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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.
261

Le contrôle continu de l'interception d'un créneau temporel en mouvement : Le cas de la traversée d'intersection. / Continuous control of the interception of a moving gap : The case of road crossing at intersection

Louveton, Nicolas 05 October 2012 (has links)
L'objectif de cette thèse est d'étudier le comportement de traversée d'intersection en conduite automobile sous l'angle des actions visuellement guidées. Dans l'introduction, nous montrons que les principales études portant sur la traversée d'intersection se sont focalisées sur les processus de jugement perceptif ; or nous montrons que la compréhension de cette activité pourrait être affinée en utilisant les concepts de la théorie de la perception directe et ceux issus du contrôle continu. Notre revue de questions nous conduit à rapprocher la tâche de traversée d'intersection à l'intérieur d'un créneau libre du trafic à celle d'interception de cible se déplaçant horizontalement. Or, dans le cadre des tâches d'interception, il a été démontré que la stratégie d'angle de relèvement constant (i.e., Constant Bearing Angle, CBA) a un fort pouvoir explicatif vis-à-vis des données expérimentales. Nous avons donc tiré partie des outils de simulation automobile pour tester la plausibilité de l'utilisation d'une telle stratégie par les conducteurs. Dans le premier chapitre expérimental, nous montrons qu'il est légitime d'étudier le couplage perception-action dans ce type de tâche et que les conducteurs adoptent des régulations comportementales proches de celles observées dans une tâche d'interception de mobile. Le second chapitre expérimental nous permet de mettre en évidence l'utilisation conjointe par les conducteurs d'informations relatives au créneau du trafic (supports globaux) et aux véhicules (supports locaux). / This Ph.D. project aims at studying drivers' road crossing behaviour under the perspective of visually guided actions. In the introduction, we present that former studies related to road crossing behaviour mainly focused on perceptual judgement processes. However, we demonstrate that this kind of task would be better understood with theories from the ecological approach of perception and motor control studies. Our literature review lead us to make a bridge between the task of crossing a road inside a free moving traffic gap and the task of intercepting an horizontally moving target. In this regard, it has been demonstrated that the Constant Bearing Angle strategy (CBA) has a high explanatory power in respect to experimental data. We used driving simulation tools in order to assess the hypothesis of the use of bearing angle based strategy by drivers. In the first experimental chapter, we show that studying perceptual-motor coupling in this task is relevant and that observed behaviour is close to taht observed in horizontally moving target interception tasks. The second experimental chapter demonstrates that drivers' behaviour relies both on visual information related to the moving gap (global contribution) and that related to the independent vehicles (local contributions). In the last experimental chapter, we evidenced that drivers' behaviour does not exclusively rely on the changes of the bearing angle but also on traffic vehicles' optical expansion. We conclude on how our results shed new light on former results obtained with perceptual-judgements based methodology.
262

Rôle de multiples affordances dans la prise de décision et la régulation de l'action chez le conducteur : L'exemple du franchissement d'intersection / Role of multiple affordances in the selection and the control of the driver’s action while attempting to cross an intersection

Marti, Geoffrey 28 May 2015 (has links)
La traversée d’intersection constitue une tâche typique dans laquelle plusieurs affordances coexistent, l’une traduisant les possibilités de franchir l’intersection, l’autre traduisant les possibilités d’immobiliser le véhicule afin d’éviter une collision. En nous inspirant des travaux de Gibson et Crooks (1938), nous avons formalisé les affordances Field of Safe Travel (FST) et Minimum Stopping Zone (MSZ) en termes de temps critique pour réussir le franchissement d’intersection et l’immobilisation du véhicule, respectivement. Grâce à un dispositif de réalité virtuelle et un simulateur de conduite, nous avons testé la prise en compte de ces affordances par un agent engagé dans la tâche de référence à travers trois expérimentations. Les résultats, appuyés par notre modèle de prise de décision, montrent que le conducteur intègre non seulement l’affordance FST, mais aussi l’affordance MSZ, dans sa décision de franchir l’intersection. De plus, l’utilisation conjointe de ces deux affordances rend compte des régulations de vitesses produites par un agent devant réaliser la tâche de franchissement en présence d’un véhicule préprogrammée ou soumis au contrôle d’un autre agent. Ces différents résultats montrent que les agents prennent en compte les différentes possibilités qui leur sont offertes (affordances FST et MSZ) pour faire un choix adapté et réguler leur vitesse. / Crossing an intersection is a typical task in which several affordances coexist, one offering the possibilities to safely cross the intersection (the main goal) and another offering the possibilities to stop the driving car to avoid a collision (the alternative goal). Based on Gibson and Crooks’ works (1938), we formalized the so-called Field of Safe Travel (FST) and Minimum Stopping Zone (MSZ) affordances in terms of critical time for safe crossing and for safe stopping, respectively. Using a virtual reality set-up with a driving simulator, three experiments have been designed to test the role of these two affordances on the decision-making and the regulation of action process. Our results, supported by a model of decision-making, reveal that drivers rely not only on the FST affordance, but also on the MSZ affordance, to choose to cross-or-not the intersection. Moreover, the joint use of these affordances is still observed when drivers have to control their velocity to perform the task when either a vehicle with a computed kinematic or a car driven by another agent is approaching. Put together, these results show that drivers take into account several possibilities for action offered by the environment (FST and MSZ affordances) to make a suitable choice and to control their speed when approaching an intersection.
263

Réflexions autour de la méthodologie de vérification des circuits multi-horloges : analyse qualitative et automatisation / Reflections on the methodology for verifying multi-clock design : qualitative analysis and automation

Kebaili, Mejid 25 October 2017 (has links)
Depuis plusieurs années, le marché des circuits intégrés numériques requiert des systèmes de plus en plus complexes dans un temps toujours plus réduit. Afin de répondre à ses deux exigences, les industriels de la conception font appel à des fournisseurs externes proposant des circuits fonctionnant sur des signaux d'horloge dédiés. Lorsque ces derniers communiquent entre eux, les horloges d'émission et de réception ne sont pas les mêmes, on parle de « Clock Domain Crossing » (CDC).Les CDC correspondent à des communications asynchrones et peuvent provoquer des dysfonctionnements critiques. Par ailleurs, ces problèmes étant intermittents et complexes à analyser, ils ne peuvent pas être exhaustivement vérifiés avec des méthodes telles que l’analyse de timing ou la simulation fonctionnelle. Avec l'augmentation du nombre de CDC dans les circuits, les industriels de la conception assistée par ordinateur (EDA) ont proposé des solutions logicielles spécialisées dans la vérification statique des CDC. Cependant, les circuits développés étant en constante évolution, les outils ne sont pas en mesure de s’adapter. Pour pallier ces problèmes, la vérification industrielle des CDC est basée sur la spécification de contraintes et d'exclusions par l'utilisateur. Ces actions, qui se substituent aux outils, peuvent masquer des bugs. De plus, l’effort humain requis par cette approche n’est pas compatible avec le temps alloué au développement de circuits industriels. Nous avons donc cherché à automatiser la vérification en proposant des solutions basées sur des propriétés formelles. Les travaux ont consisté à analyser les différentes techniques de conception et de vérification des CDC à travers l’évaluation des principaux outils du marché. A partir des résultats obtenus, nous avons formalisé les problèmes pratiques et proposé des modèles permettant d’obtenir des résultats exhaustifs automatiquement. Les essais ont été réalisés sur un sous-système à base de processeurs (CPUSS) développé chez STMicroelectronics. L'adoption de nos modèles permet une vérification complète des CPUSS de manière automatique ce qui est essentiel dans un environnement industriel compétitif. En effet, le nombre d’informations devant être spécifiées par l’utilisateur a été réduit de moitié pour chacun des outils évalués. Par ailleurs, ces travaux ont montré que l’axe de développement des outils CDC avec l’ajout de fonctionnalités telles que les flots hiérarchiques ou l’injection de fautes n’améliore pas la qualité de résultats. Une collaboration ayant été mise en place avec les principaux fournisseurs outils, certaines solutions seront probablement intégrées aux outils dans les années à venir. / For several years now, the digital IC market has been requiring both more complex systems and reduced production times. In this context, the semiconductor chip maker companies call on external IP providers offering components working on dedicated clock signals. When these IPs communicate between them, the source and destination clocks are not the same, we talk about "Clock Domain Crossing" (CDC).CDC correspond to asynchronous communications and can cause critical failures. Furthermore, due to the complexity and the random nature of CDC issues, they can not be exhaustively checked with methods such as timing analysis or functional simulation. With the increase of CDC in the digital designs, EDA tools providers have developed software solutions dedicated to CDC static verification.Whereas, the designs are subject to continuous change, the verification tools are not able to be up to date. To resolve these practical issues, the CDC industrial verification is based on the specification of constraints and exclusions by the user. This manual flow, which replaces the tools, can mask bugs. Moreover, the human effort required by this approach is incompatible with the time allowed to industrial designs development.Our goal has been to automate the verification submitting solutions based on formal properties.The work consisted in the analysis of the different CDC design and verification approaches through the evaluation of main CDC checker tools. From the results obtained, we have formalized the practical problems and proposed models to obtain automatically exhaustive results. The tests have been performed on a processor-based subsystem (CPUSS) developed at STMicroelectronics.Adopting our models enables a complete checking of CPUSS in an automatic way, which is essential within a competitive industrial environment. Actually, the amount of information to be specified by the user has been reduced by half for each one of the evaluated tools. Otherwise, this work has shown that the development axis of the CDC tools despite the addition of functionalities such as hierarchical flows or fault injection, doesn’t improve the quality of results (QoR). Since a collaboration has been established with the main tool providers some solutions would probably be included into the tools over the coming years.
264

De exílio em exílio: um diálogo entre Eurípides e Clara de Góes na peça Medea en Promenade / From exile to exile:a dialogue between Euripides and Clara de Góes in the play Medea en Promenade

Silva, Francisca Luciana Sousa da January 2015 (has links)
SILVA, Francisca Luciana Sousa da. De exílio em exílio: um diálogo entre Eurípides e Clara de Góes na peça Medea en Promenade. 2015. 166f. – Dissertação (Mestrado) – Universidade Federal do Ceará, Programa de Pós-graduação em Letras, Fortaleza (CE), 2015. / Submitted by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2016-08-05T16:39:01Z No. of bitstreams: 1 2015_dis_flssilva.pdf: 3767809 bytes, checksum: 6ba722a9950245ad0a7f31c2684e2366 (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2016-08-05T17:10:47Z (GMT) No. of bitstreams: 1 2015_dis_flssilva.pdf: 3767809 bytes, checksum: 6ba722a9950245ad0a7f31c2684e2366 (MD5) / Made available in DSpace on 2016-08-05T17:10:47Z (GMT). No. of bitstreams: 1 2015_dis_flssilva.pdf: 3767809 bytes, checksum: 6ba722a9950245ad0a7f31c2684e2366 (MD5) Previous issue date: 2015 / This dissertation analyzes the unpublished text by Clara de Góes, Medea en Promenade (2012), based on the homonymous tragedy of Euripides' Medea (431 BC). The target text narrates the meeting of Glauce, (the young one), Medea (the woman) and the love of Medea (the old one), three women "in a sort of desert outside of time and space" according to the words of the author. Punctuating the speech of these women, the voice of Corifeu is perceived, often in the dark. Thus, we propose a critical reflection, turning our gaze to the protagonists of this poetic work, whose speeches are characterized by the following questions: "What is my place in exile? Do I belong to the exile ? "Such questions reinforce a longstanding demand of women, not only in Athens, but in many other places, especially the foreign ones. In order to understand these banks and the reason why there are so many crossings, many of them forced, we choose exile as a theme, considering it a object of interest not only of the Classics, but also of the cultural studies, for example. Our aim is to show, comparatively, how the so called "dialogue" between Euripides and Clara Garcia is constructed, trying also to discover another reading for the Medea myth, parallel or beyond the metaphor itself, concerning especially the heroin journeys. As pointed out by Jan Felix Gaertner, one of the authors that support our research, exile "has been one of the most productive literary themes in the literature of the twentieth century" (2007, p. 1) and has become a central theme in postcolonial literature or in association with another themes related to distance, separation, displacement, detachment and diaspora. Our hypothesis is to recognize the exile as a device, as Agamben would define (2009) – a key technical term in Foucault's thinking strategy, - not only a political device but also an existential one. All of this analysis, according to Medea, of Euripides, who immortalized her as an infanticide, but not without questioning her status as a foreign woman. In order to study this condition, we support ourselves especially in the works of Pierre Vidal - Naquet (1999) and Vernant (2009), Queiroz (1998) and Jasinski (2012). The following studies don’t seem to contradict our hypothesis, given their hybridization aspect: Sara Forsdyke (2005) and Gayatri C. Spivak (2014). The theoretical syllabus about the theater - from Greek tragedy to the contemporary scene – is based on the following works: Albin Lesky, Jacqueline Rommily, Marie - Claude Hubert and Patrice Pavis (2011). / A presente dissertação analisa o texto de Clara de Góes, Medea en Promenade (2012), a partir da tragédia homônima de Eurípedes, Medeia, (431 a.C.). O texto de chegada narra o encontro de Glauce, (Jovem), Medeia (Mulher) e a ama de Medeia (Velha), três mulheres “em uma espécie de deserto fora do tempo e do espaço”, nas palavras da autora. Pontuando a fala dessas mulheres, ouvimos a voz do Corifeu, quase sempre à penumbra. Propomos, assim, uma reflexão crítica, voltando nosso olhar para as protagonistas dessas poéticas, cujas falas são marcadas por questionamentos: “Qual meu lugar no exílio? Seria o exílio meu lugar?” Tais perguntas reforçam uma antiga reivindicação das mulheres, não só de Atenas, mas de muitos outros lugares, especialmente as estrangeiras. Foi buscando entender essas margens e o porquê de tantas travessias, muitas delas forçadas, que elegemos o tema do exílio, haja vista constituir objeto de interesse não só dos Estudos Clássicos, mas também dos Estudos Culturais, por exemplo. Nosso intuito é mostrar como ocorre o que ora chamamos “diálogo” entre Eurípides e Clara de Góes, numa perspectiva comparada, buscando imprimir outra leitura para o mito de Medeia, paralela ou além da metáfora, especialmente voltada para os constantes deslocamentos da heroína. Como salienta Jan Felix Gaertner, um dos autores que fundamentam nossa pesquisa, o exílio “tem sido um dos temas literários mais produtivos em literatura do século XX” (2007, p. 1) e tornou-se um tema central na literatura pós-colonial em associação a temas relacionados a distância, separação, deslocamento, desprendimento e diáspora. Nossa hipótese é reconhecer ou ler o exílio como dispositivo, conforme Agamben (2009) – termo técnico decisivo na estratégia do pensamento de Foucault, do qual foi tomado de “empréstimo” – não só político, mas também existencial, a partir da Medeia, de Eurípides, que a imortalizou como infanticida, não sem antes problematizar seu status de mulher estrangeira. A respeito dessa condição, apoiamo-nos, especialmente, em Pierre Vidal-Naquet (1999) e Vernant (2009), Queiroz (1998) e Jasinski (2012). A fim de confirmar, em parte, nossa hipótese, dado o hibridismo da análise, apoiamo-nos em Sara Forsdyke (2005) e Gayatri C. Spivak (2014). Como aporte teórico do teatro – da tragédia grega à cena contemporânea –, Albin Lesky (2010), Jacqueline de Romilly (2013), Marie-Claude Hubert (2013) e Patrice Pavis (2011).
265

Análise de variabilidade genética em populações segregantes de soja

Muniz, Franco Romero Silva [UNESP] 28 September 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-28Bitstream added on 2014-06-13T18:43:25Z : No. of bitstreams: 1 muniz_frs_dr_jabo.pdf: 1182648 bytes, checksum: 94ba816afe15c07503cde37414bc5a99 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A variabilidade entre progênies é criada pela segregação cromossômica independente dos genes e pela recombinação genética intracromossomal durante a meiose. O objetivo deste estudo foi analisar a variabilidade derivada de crossing-overs em cruzamentos biparentais (G2 e J2), quádruplos (G4 e J4) e óctuplos (G8 e J8), avaliados em populações segregantes derivadas de parentais contrastantes para resistência ao nematóide de cisto da soja (raça 3) – NCS – e ao oídio - O. A análise foi realizada em populações F2, através de marcadores SSR (single sequence repeat) concentrados em uma região de 55 cM ao redor do gene rmd (resistência ao oídio) e rhg1 (resistência ao NCS). Após o teste dos marcadores, quanto ao polimorfismo, apenas marcadores polimórficos foram utilizados para detectar crossing-over. Todos os marcadores analisados foram não significativos pelo teste de qui-quadrado (P > 0,05), indicando que os valores observados se ajustam à proporção genotípica esperada em F2 (1:2:1). As maiores médias de crossing-over por genótipo foram obtidas para G4 (4,00), no grupo G, e J8 (2,91), no grupo J. Por outro lado, as maiores médias de crossing-over considerando o número de gerações para formar cada população, foram para G2 (2,02) e J8 (0,97). A recombinação entre alelos ocorreu em algumas populações, entretanto para G4 e J8 em 1,89% dos genótipos não ocorreram. Em geral, nos cruzamentos com maior número de parentais envolvidos a ocorrência de crossingover foi maior, sendo satisfatórios na criação de variabilidade. O progresso no melhoramento de soja tem sido alcançado em partes pela criação de novas combinações alélicas dentro dos cromossomos. / The variability among the progenies is created by chromosome segregation, independent assortment of genes, and intra-chromosomal genetic recombination during meiosis. The objective of this study was to analyze the variability derived from crossovers in soybean biparental (G2 and J2), quadruple (G4 and J4) and octuple (G8 and J8) crosses, measured in segregant population derived from contrasting parental regarding their resistance to cist nematode (race 3) – SCN and powdery mildew – PM. The analyses were made in F2 population through SSR (single sequence repeat) markers located in a 55CM region around Rmd (powdery mildew) and Rhg1 (cist nematode) resistance genes. After screening makers for their polymorphism, only polymorphic markers were used to detect crossovers. All markers were not significant by chi-square test (P > 0.05), showing that observed values corroborates to genotypic inheritance ratio expected in F2 population (1:2:1). Thus, the higher average of crossovers for some populations were observed for G4 (4.00), at linkage group G and J8 (2.91), at linkage group J. On the other hand, the higher average of crossovers considering the generation number to form each population, was found for G2 (2.02) and J8 (0.97). The recombination between alleles occurred in some populations, however, to G4 and J8, in 1.89% of the genotypes not showing crossover. In general, the crosses with larger numbers of parents showed higher number of crossovers, being very satisfactory for the creation of genetic variability. Soybean breeding progress has been accomplished in part by creating on new within_chromossome allele combinations.
266

HODNOCENÍ UŽITKOVÝCH PARAMETRŮ U PLEMEN KAPRA OBECNÉHO A JEJICH KŘÍŽENCŮ / EVALUATE THE PERFORMANCE PARAMETERS OF THE BREEDS OF COMMON CARP AND ITS CROSSBREDS

KŘÍŽ, Michal January 2009 (has links)
The aim of the thesis was to evaluate the performance parameters of the breeds of common carp and its crossbreds by using the top-crossing. On the maternal position the Hungarian synthetic mirror carp line (HSM) was used. On this line, males of HSM, Telč mirror carp (TeL), Northern mirror carp (M72) and Amur mirror carp (AL) were crossed and a hybrid of Ropsha carp (ROP) and Tata carp (TAT) was used as their control group. Rearing of the tested groups was monitored from larval stage until their market size in ponds with a semi-intensive way of management in three localities (2 organisations). In the first year, each tested group was bred individually with internal control group of a different scaly covering phenotype in order to correct the influence of the environment on the weight achieved. In the second and the third year, all the groups were group-labelled and bred together in triplicate (three ponds) localities. In the individual stages of testing, the weight and the survival rate were recorded. Moreover, in the market size stage the biometric measurement and slaughtering value were evaluated. In the overall assessment of the results from all the localities carried out by the ANCOVA procedure, the highest weight at the K3 age was achieved by the hybrid HSM x AL (1413 {$\pm$} 31.5 g; Last square means {$\pm$} S.E.), whose weight was statistically comparable to the other hybrids (HSM x M72 a HSM x TeL). However, it was the only noticeably higher weight in comparison with the HSM (1257 {$\pm$} 31.5 g) with its ordinary heterosis effect of growth on the level of 12.4%. During the third year of testing, the survival ranged from 69.0 % in HSM x Tel to 73.4% in HSM x AL and the values were statistically comparable. The yield parameters (the proportion of the processed body, the proportion of filets with skin and the skinless ones) were similar in all the groups. In the previous periods of testing the results reflected the situation in the market size. As a result, it is concluded that preferably the hybrid HSM x AL could be exploitable in commercial breeding.
267

Výsledky masné užitkovosti býků různých genotypů / Results of meat performance in bulls of various genotype

ŠIMÁK LÍBALOVÁ, Kristýna January 2010 (has links)
A growing number of pure-bred herds of beef breeds began to grow a herd of cows with a dual-purpose efficiency type, farmers often use their crosses with beef breeds of cattle to increase their meat performance. The aim of this diploma work was to analyse results of fattening ability and carcass value of Czech Pied Cattle bulls (C) and their crosses with beef breeds. In evaluation selected indicators were included 907 slaughtered bulls dividing according their genotype. The software programs Microsoft Excel and Statistica has been used for processing calculations and the statistic data. An important indicator is achieved dressed carcass weight (DCW), which was highest in bulls Meat Siemental (SI) 370.1 kg, Aberdeen Angus (G) 359.0 kg and crossbreeds Charolais and Czech Pied Cattle (TxC) 354.2 kg. Lowest DCW had extensive breed Highland (E) and Galloway (W) 318.8 kg. The difference between SI and E + W was 51.3 kg and was highly statistically significant (P {$\leq$} 0.001). The group of TxC and TxH and breed Piemontese (P) had the highest intensity of growth, net gain was 671.5 g, resp. 669.6 g for T and crosses and 652.5 g for the breed P. The lowest average net gain was found in the breed G (531.3 g). The highest production of first quality meat was found in the breed P (55.6 kg), 55.4 kg was achieved in breed SI. At least meat I. grade was found in bulls of E and W (47.2 kg). Significant difference was found between SI and E + W at a significance level P {$\leq$} 0.001. Based on the results we can recommend commercial crossings Czech Pied cattle with bulls meat breed or breeding pure-bred beef breeds. It is important to take into account the specificity of each breed, its earliness and size of body frame in the choice of slaughter weight and age of fattening bulls, to avoid unwanted growth of fat in bulls, and to realize the slaughter weight trough the most intensive fattening.
268

Analytic Selection of a Valid Subtest for DIF Analysis when DIF has Multiple Potential Causes among Multiple Groups

January 2014 (has links)
abstract: The study examined how ATFIND, Mantel-Haenszel, SIBTEST, and Crossing SIBTEST function when items in the dataset are modelled to differentially advantage a lower ability focal group over a higher ability reference group. The primary purpose of the study was to examine ATFIND's usefulness as a valid subtest selection tool, but it also explored the influence of DIF items, item difficulty, and presence of multiple examinee populations with different ability distributions on both its selection of the assessment test (AT) and partitioning test (PT) lists and on all three differential item functioning (DIF) analysis procedures. The results of SIBTEST were also combined with those of Crossing SIBTEST, as might be done in practice. ATFIND was found to be a less-than-effective matching subtest selection tool with DIF items that are modelled unidimensionally. If an item was modelled with uniform DIF or if it had a referent difficulty parameter in the Medium range, it was found to be selected slightly more often for the AT List than the PT List. These trends were seen to increase as sample size increased. All three DIF analyses, and the combined SIBTEST and Crossing SIBTEST, generally were found to perform less well as DIF contaminated the matching subtest, as well as when DIF was modelled less severely or when the focal group ability was skewed. While the combined SIBTEST and Crossing SIBTEST was found to have the highest power among the DIF analyses, it also was found to have Type I error rates that were sometimes extremely high. / Dissertation/Thesis / Doctoral Dissertation Educational Psychology 2014
269

Distribuições e estatisticas de ordem superior para o canal sem fio / Distributions and higher-order statistics for wireless channels

Fraidenraich, Gustavo, 1975- 02 July 2006 (has links)
Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T02:52:07Z (GMT). No. of bitstreams: 1 Fraidenraich_Gustavo_M.pdf: 1838522 bytes, checksum: 4099008fa7bbc89eb2642a891bd64509 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho, uma nova distribuição de probabilidade amplamente geral, a distribuição a-?-?-µ, é proposta. Esta distribuição contempla como casos particulares várias outras distribuições conhecidas na literatura, tais como Rayleigh, Rice, Nakagami-m, Hoyt, Weibull, a-? (Gamma Generalizada) ?-µ e ?-µ. Por conta de sua generalidade, todos os mais importantes ambientes de desvanecimento de curto prazo são modelados por esta distribuição. Além de prover a função densidade de probabilidade para o modelo a-?-?-µ, os momentos e a função cumulativa de probabilidade também são encontrados. Este modelo geral é então especializado para quatro casos particulares, para os quais distribuições mais simples, mas ainda gerais, são encontradas: a a-?-µ, a-?-µ, ?-? Simétrica e ?-? Assimétrica. Para esses casos, estimadores práticos baseados nos momentos são deduzidos. A aplicabilidade destes estimadores é verificada utilizando medidas de campo realizadas na Unicamp com um equipamento construído no laboratório Wisstek para este ?m. Em seguida, estatísticas de ordem superior, em particular a taxa de cruzamento de nível e a duração média de desvanecimento, são encontradas de forma exata para os ambientes Hoyt e Weibull em sistemas de diversidade com M ramos desbalanceados, não idênticos e independentes utilizando os combinadores por ganho igual e por razão máxima. Neste trabalho, o resultado geral é validado através de simulações e redução das expressões gerais para casos em que os resultados já são conhecidos. Além disso, para alguns destes casos particulares, as expressões gerais são simplificadas e reduzidas a fórmulas fechadas. Estendendo esse último campo de investigação e seguindo um pioneiro trabalho da literatura, o qual abordou o caso Rayleigh, a taxa de cruzamento de nível e a duração média de desvanecimento são obtidas para ambientes Hoyt com dois ramos correlacionados. Nesta investigação, reformula-se a metodologia da literatura e obtém-se um procedimento geral para a análise da taxa de cruzamento de nível e duração média de desvanecimento em ambientes com apenas um cluster, com aplicação direta aos canais Rice, Weibull, ?-? Simétrica e ?-? Assimétrica. Finalmente, este trabalho propõe, de forma precursora, uma distribuição para a fase do canal Nakagami-m. Ao contrário do que, convencionalmente e por simplicidade, se postulava, a distribuição de fase é não uniforme e dependente de m, o que torna o modelo compatível com aqueles aproximados por Nakagami-m, nomeadamente Hoyt e Rice / Abstract: In this work, a new, very general probability density function, the a-?-?-µ distribution, is proposed. This distribution comprises, as particular cases, several other well known distributions such as Rayleigh, Rice, Nakagami-m, Hoyt, Weibull, a-? (Generalized Gamma) ?-µ and ?-µ. Due to its generality, all of the most important short fading environments can be modeled by this distribution. Besides providing the probability density function for the a-?-?-µ model, the moments and the cumulative distribution function are also found. This general model is then specialized into four particular cases, for which new simpler, though still general, distributions, are found: the a-?-µ, a-?-µ, Symmetrical ?-?, and Asymmetrical ?-?. For these cases, practical moment-based estimators are derived. The applicability of these estimators is verified using field measurements obtained through an experiment conducted at the University of Campinas (Unicamp) with an equipment specially built for this end in the Wisstek laboratory. Higher order statistics, more specifically the level crossing rates and average fade durations, are then obtained in an exact form for the Hoyt and Weibull fading environments. The results are applicable to M unbalanced, non-identical, and independent channels using equal gain and maximal ratio combining techniques. The general results are thoroughly validated by means of simulation and also by reducing the general solution to some particular cases for which the solutions are known. Moreover, new closed form expressions are also achieved for some of these particular cases. Extending this field of investigation and following a pioneering work in the literature, which approached the Rayleigh case, the level crossing rate and average fade duration are obtained considering two correlated, unbalanced, and non-identical branches in a Hoyt fading environment. In this investigation, the methodology found in the literature is reformulated and generalized so as to comprise several other cases. The general procedure developed for this analysis can now be applied to other fading environment for which one cluster of mutipaths exists, i.e., Rice, Weibull, Symmetrical ?-?, and Asymmetrical ?-?. Finally, this work proposes, in a pioneering way, the phase distribution for the Nakagami-m channel. Contrary to what conventionally, and for simplicity, was usually postulated, the phase distribution is non-uniform and dependent on m, rendering this model compatible with those approximated by Nakagami-m, namely Hoyt and Rice / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
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Assessment of crosses of sheep breeds dorp, poll dorset, santa inÃs and somalis brazilian / AvaliaÃÃo de cruzamentos de ovinos das raÃas dorper, poll dorset, santa inÃs e somalis brasileira

Adriano Caminha Barbosa Neto 25 April 2008 (has links)
FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / O objetivo deste trabalho foi de analisar as caracterÃsticas de crescimento, reprodutivas e de habilidade materna de vÃrios grupos genÃticos compostos pelas raÃas Santa InÃs, Somalis Brasileira, Dorper, Poll Dorset, e seus cruzamentos, avaliando os diversos fatores genÃticos e nÃo genÃticos envolvidos. Foram utilizados registros de peso ao nascer (PN), peso ao desmame (PD), ganho de peso do nascimento ao desmame (GP), peso total de crias ao nascimento por matriz (PTCN), peso total de crias ao desmame por matriz (PTDC), idade ao primeiro parto (IPP), intervalo de partos (IDP) e perÃodo de gestaÃÃo (PG), no perÃodo de 1998 a 2007. Os dados foram oriundos de animais da Gaasa e Alimentos LTDA, localizada no MunicÃpio de Inhumas-GO, uma fazenda assistida pelo Programa de Melhoramento GenÃtico de Caprinos e Ovinos de Corte (GENECOC), pertencente à Empresa Brasileira de Pesquisa AgropecuÃria - Embrapa Caprinos. Os modelos de anÃlises foram definidos pelo procedimento MIXED do pacote estatÃstico SAS, apÃs a verificaÃÃo das restriÃÃes e limitaÃÃes dos dados. As avaliaÃÃes dos efeitos genÃticos aditivos e nÃo aditivos, e as estimativas dos componentes de (co)variÃncia foram obtidos pelo mÃtodo da mÃxima verossimilhanÃa restrita (REML), usando um algoritimo livre de derivadas, sob um modelo animal, utilizando o programa Multiple Trait Derivative-Free Restricted Maximum Likelihood (MTDFREML). Para as caracterÃsticas PN, PD e GP, utilizou-se o modelo animal considerando como aleatÃrios os efeitos genÃticos aditivos direto e maternos, o efeito de ambiente permanente materno e os efeitos residuais, enquanto os efeitos fixos foram os de grupo de contemporÃneos, interaÃÃo do sexo com o tipo de nascimento e classe de idade da mÃe, alÃm das (co)variÃveis para a obtenÃÃo das estimativas dos efeitos genÃticos aditivos diretos de cada raÃa, do efeito da heterose individual e heterose materna e do efeito de recombinaÃÃo. Para as caracterÃsticas PTCN, PTCD, IDP e PG, incluÃram-se o efeito genÃtico aditivo direto e o efeito de ambiente permanente do animal como aleatÃrios e os efeitos de grupo de contemporÃneas, ordem de parto e interaÃÃo do sexo com o tipo de nascimento das crias como fixos, alÃm das (co)variÃveis para a obtenÃÃo das estimativas do efeito genÃtico aditivo direto de cada raÃa, da heterose individual e de recombinaÃÃo. Jà para a IPP foram incluÃdos estes mesmos efeitos, exceto o efeito de ambiente permanente do animal. As anÃlises do desempenho mÃdio do rebanho para as caracterÃsticas estudadas foram de 3,75 kg, 14,91 kg, 0,200 kg/dia, 4,82 kg, 16,21 kg, 604,11 dias, 283,07 dias e 150,51 dias, respectivamente para PN, PD, GP, PTCN, PTCD, IPP IDP e PG. As estimativas para a diferenÃa genÃtica aditiva entre as raÃas ovinas foram significativas para todas as caracterÃsticas, exceto para o IDP. Os efeitos de heterose individual e materna tambÃm foram significativos para todas as caracterÃsticas, exceto para o PN (individual e materna) e para o GP (individual). Foi observada significativa perda por recombinaÃÃo para PD, GP, IPP e PG. As estimativas de herdabilidade para as PN, PD e GP foram de 0,38, 0,14 e 0,10, respectivamente, para herdabilidade direta e de 0,27, 0,09 e 0,04, respectivamente, para herdabilidade materna. Jà as estimativas de herdabilidade direta para PTCN, PTCD, IPP, IDP e PG foram de 0,19, 0,05, 0,21, 0,02 e 0,10, respectivamente. Foi observada a reduÃÃo do desempenho em vÃrias das caracterÃsticas estudadas, em funÃÃo de perdas por recombinaÃÃo. Isto significa que a formaÃÃo de uma populaÃÃo sintÃtica a partir das raÃas envolvidas neste estudo à uma aÃÃo bastante complexa, exigindo um rigoroso e bem conduzido processo de seleÃÃo para neutralizar estes efeitos indesejÃveis. Nas condiÃÃes do presente estudo, os genes da raÃa Somalis Brasileira contribuÃram para um melhor desempenho reprodutivo. Por outro lado, conduziu a reduÃÃo no ganho de peso, quando comparado Ãs demais raÃas estudadas / The aim of this study was to analyze growth, reproductiv e and maternal traits from Santa InÃs, Brazilian Somali, Dorper and Poll Dorset breeds and its crosses, evaluating the genetic and non-genetic factors presented. Records of birth weight (BW), weaning weight (WW), weight gain from birth to weaning (WG), litter weig ht at birth (LWB), litter weight at weaning (LWW), age at first lambing (AFL), lambing interval (LI) and gestation length (GL), between 1998 and 2007, were utilized. Data were from animals of the Gaasa e Alimentos LTDA, located in Inhumas-GO, a herd assisted by Programa de Melhoramento GenÃtico de Caprinos e Ovinos de Corte (GENECOC), of Empresa Brasileira de Pesquisa AgropecuÃria - Embrapa Caprinos. The analysis models were defined by MIXED procedure of the statistical package SAS, after verification of restrictions and limitations of data. The evaluations of additives and non-additives genetic effects, and the estimates of (co)variance components were obtained by Restricted Maximum Likelihood method (REML), using a derivative-free algorithm under animal model, using the software Multiple Trait Derivative-Free Restricted Maximum Likelihood (MTDFREML). For the traits BW, WW and WG, the animal model accomplished direct and maternal addictive genetic effects, maternal permanent environmental effect and residual effects as aleatory, while the fixed effects were contemporary group, interaction of sex with birth type and class of the mother's age, besides the(co)variables for the obtaining of the estimates of direct addictive genetic effects of each breed, individual heterosis effects, maternal heterosis effects and recombination e ffects. For the traits LWB, LWW, LI and GL, direct addictive genetic effects and individual permanent environmental effects were included in the model as aleatory and contemporary group, lactation order and in teraction of the sex with birth type effects as fixed, besides the (co)variables for the obtaining of the estimates of direct addictive genetic effect s breed, individual heterosis effects and recombination effects. Already for AFL, all effects were included, except the individual permanent environmental effect. The averages for the the studied traits were 3,75 kg, 14,91 kg, 0,200 kg/day, 4,82 kg, 16,21 kg, 604,11 days, 283,07 days and 150,51 days for BW, WW, WG, LWB, LWW, AFL, LI and GL, respectively. The estimates for the addictive genetic differences among the breeds were also significant for all the traits, except for LI. The individual and maternal heterosis were also significant for all the traits, ex cept for BW (individual and maternal) and WG (individual). Significant recombination losses were observed for WW, WG, AFL and GL. The direct heritabilities for BW, WW and WG were 0,38, 0,14 and 0,10, respectively, while maternal heritabilities for the same traits were 0,27, 0,09 and 0,04, respectively. Already the direct heritabilities for LWB, LWW, AFL, LI and GL were 0,19, 0,05, 0,21, 0,02 and 0,10. Reduction of performance were observed in many studied traits due losses by recombination. This means that the formation of a synthetic breed from the breeds involved in this study is a complex action, requiring a rigorous and well conducted process of selection to neutralize these undesirable effects. In the conditions of this study, the genes of Brazilian Somali contributed to improve reproductive performance. On the other hand, it contributed to reduction of weight gain when compared to the other breeds studied.

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