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Desempenho Produtivo e Comportamento Ingestivo de Novilhas Angus x Nelore em Sistemas Integrados de Produção AgropecuáriaSantos, Juliana Mara de Freitas dos January 2019 (has links)
Orientador: Cristiana Andrighetto / Resumo: O objetivo deste trabalho foi avaliar a produção, valor nutritivo e capacidade de suporte do capim Marandu, desempenho produtivo e comportamento ingestivo de novilhas meio sangue Angus x Nelore. O experimento foi conduzido na APTA – Andradina, SP em Sistemas Silvipastoris, sendo: SSP-1 com 187 árvores/ha, SSP-2 com 446 árvores/ha, associado ao Eucalyptus urograndis, clone I-224 (17 e 18,7m de altura respectivamente) e Sistema Convencional (SC), ambos em pastagens de Urochloa brizantha cv. Marandu. Para as avaliações da forragem, foram realizadas: massa seca total, análise bromatológica, desempenho animal e taxa de lotação nas estações inverno e verão. Para o comportamento ingestivo, realizou-se quatro coletas: uma no início e outra no final das estações inverno e verão. Foram observados os seguintes comportamentos: pastejo, ruminação (em pé e deitado), ócio (em pé e deitado), outras atividades, que incluem: interação com outros animais, ida ao bebedouro e ao cocho, urinar e defecar e deslocamento. Concomitantemente, foram avaliados as seguintes variáveis microclimáticas: temperatura de globo negro, temperatura ambiente, umidade relativa do ar e velocidade do vento. A partir destes dados, foram calculados os seguintes índices de conforto térmico: índice de temperatura e umidade (ITU), índice de temperatura de globo e umidade (ITGU) e carga térmica radiante (CTR). O delineamento experimental foi em blocos completos com 3 tratamentos e 4 repetições. Os dados foram submetidos às ... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
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Risco nas passagens de nível ferroviárias: lições do caso do acidente de Americana-SP / Risk on railway grade crossings: lessons from accident case of AmericanaSPManoela Gomes Reis Lopes 16 March 2012 (has links)
Introdução - O cruzamento do modal ferroviário com rodoviário em um mesmo nível é chamado de passagem de nível (PN), os quais apresentam baixa freqüência de acidentes, porém elevados índices de gravidade. No dia 08 de setembro de 2010, em Americana-SP, ocorreu acidente envolvendo dois trens e um ônibus em uma PN, com dez vítimas fatais e dezessete feridos, dos quais quatro foram registrados como acidentes de trabalho. Objetivo - Analisar origens imediatas e latentes desse acidente visando evitar ou minimizar as chances de ocorrência de eventos semelhante no futuro. Método - Estudo de caso que foi realizado através da pesquisa de artigos, livros, jornais e reportagens televisivas sobre o assunto. Após essa etapa, foram realizadas entrevistas com pessoas envolvidas no acidente, como canceleiros, motoristas de ônibus e maquinistas. O Modelo de Análise e Prevenção de Acidentes de Trabalho (MAPA), que propõe uma abordagem sistêmica do caso, foi usado na análise do evento. Resultados - O local é mal iluminado e com presença de construções que dificultam a visualização dos trens. Essa PN apresenta intenso tráfego de pedestres e de carros mesmo com o sinal fechado. O motorista informou que o sinal vermelho só foi acionado quando o ônibus já estava no meio da PN, instantes antes do choque. As condições de trabalho dos motoristas de ônibus e maquinistas são inadequadas com uma prática freqüente de horas extras e às vezes não é respeitado o intervalo legal de 11 horas entre uma jornada e outra. As barreiras presentes na PN eram apenas simbólicas. O sistema de comunicação entre canceleiros, motoristas e maquinistas é dependente da ação humana sendo considerado frágil. Os entrevistados afirmaram já ter presenciado acidentes em PN, confirmando a fragilidade do sistema. O acidente foi investigado pelo Instituto de Criminalística que considerou o motorista do ônibus culpado pela ocorrência, sendo atualmente objeto de processo criminal correndo o risco de ser condenado e preso. Conclusão - O acidente foi um evento complexo, com a interação entre, pelo menos os seguintes componentes: o sistema de transporte rodoviário urbano, com destaque para a ação do motorista do ônibus; o transporte ferroviário e o trabalho dos maquinistas dos trens; o sistema de controle da PN que envolve o trabalho dos canceleiros encarregados da sinalização de aproximação dos trens; a concepção, gestão e manutenção da segurança da PN, o sistema viário urbano que inclui a iluminação pública / Introduction - The railway crossing with the road on the same level is called Grade Crossing (GC), which present low incidence of accidents, however, when they happen, they usually present high rates of severity. On September 8th, 2010, in Americana-SP, there was an accident involving two trains and one bus on a GC, with ten people died and seventeen were injured, four of which were registered as work accident. Aim - To analyze the immediate and latent causes of the accident attempting to avoid or minimize the chances of similar events to happen in the future. Method Case study that was performed by means of research from articles, books, newspapers and TV reports about the subject. After this phase, interviews were carried out with people involved in the accident, like watchmen, bus drivers and train operators. The Model of Analysis and Prevention of Work Accidents (MAPA), which proposes a systemic approach of the event, was used as a guide. Results - The site is poorly lit and with the presence buildings that obstruct the visualization of the trains coming to it. This GC has intense traffic of pedestrians and cars when the traffic signal is closed. The driver said that the red traffic signal was only triggered when the bus was in the middle of GC, moments before the collision. The work conditions bus drivers and driver of train are inadequate with a frequent practice of overtime and sometimes not respected the legal range of 11 hours between one day and another. At the time the accident happened, there were only symbolic barriers. The system of communication among watchmen, bus drivers and train operators depends on the human action being considered weak. The people interviewed said they had seen accidents on GC, which confirmed the fragility of the system. The accident was investigated by the Institute of Forensic Science which has considered the bus driver guilty of the occurrence, nowadays being object of criminal procedure and may be condemned and arrested. Conclusion - The accident was a complex event, with the interaction among, at least: the system of urban road transport, especially the action of the bus driver; the rail transport and the work of trains operators; the control system of GC, that involves the work of watchmen that are responsible by traffic signal at the approaching of trains; those in charge of design, management and maintenance of safety issues in the GCs and those in charge of the urban road system that includes lighting
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PCR-RFLP no ?xon II do gene da leptina e avalia??o das caracter?sticas f?sicas da carne de caprinos machos inteiros saanen e cruzados saanen X boer / PCR-RFLP in exon II of the leptin gene and evaluation of the physical characteristics of meat from boars Saanen goats and crossed Saanen x BoerSilva, Rebecca Barbosa 04 March 2016 (has links)
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Previous issue date: 2016-03-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Molecular markers are important tools in the marker assisted selection programs (MAS).
Leptin is expressed hormone mainly in the adipocytes and involved in the regulation of
energy metabolism, fat deposition, regulation of glycemia and reproductive physiology and
thus has been investigated in association studies quality carcass characteristics and meat in
different species. Objective with this work identify the polymorphism in the Leptin gene,
changes in qualitative and quantitative characteristics of meat and goat carcass and relate
variations of productive features to potential polymorphisms. They were used for genotyping
38 goats intact males, 21 Saanen and 17 crusaders Boer x Saanen. Genotypes for the marker
were identified by PCR-RFLP technique based on standardized protocols for SNP305. DNA
samples were isolated from leukocyte genomic and amplified through reaction technique
Polymerase Chain Reaction (PCR). The generated PCR fragments of 94 base pairs (bp) were
digested by Kpn2I enzyme yielding two fragments 75 (bp), 19 (bp) for all individuals
analyzed, obtaining allelic frequency of 100% for T. Thus genotype, it was not possible to
correlate the results obtained in the evaluation of quality meat and carcass to the results of the
molecular study. For the evaluation of carcass quality and meat was used 18 male, 9 Saanen
and Saanen x 9 crusaders Boer. t test was used for independent samples of the statistical
program BioEstat the 5% significance (P<0.05) for morphometric measurements, live weight,
live weight after fasting, hot carcass weight, cold carcass weight, cooling breaks, carcass
yield, loss of cooling, thick fat cover, color, pH, water holding capacity and tenderness of the
meat, weight and yield cuts (shoulder, hand saw, rib set, ham and loin) and compactness
index of carcass. The grouping of the Crusaders animals showed significant differences
(P<0.05) for wide shank and shear force. For Saanen animals, there was a significant
difference (P<0.05) for the external length of the housing. Although Crossed have shown
higher shear strength values (P<0.05), the two groups had average below 5.4 kg-f cm-?,
featuring soft meats in goats (2.20 and 1, 57 kg f cm-2 for Crossed and Saanen, respectively).
The results showed that the use of both the Crusaders animals, as the Saanen animals are a
viable option for dairy farmers who wish to diversify their activities, taking advantage of the
disposal of male goats for meat production / Os marcadores moleculares s?o importantes ferramentas nos programas de sele??o assistida
por marcadores (MAS). A Leptina ? um horm?nio expresso principalmente nos adip?citos e
est? envolvido na regula??o do metabolismo energ?tico, deposi??o de gordura, regula??o da
glicemia e fisiologia reprodutiva e por isso tem sido investigado em estudos de associa??o a
caracter?sticas de qualidade de carca?a e carne em diferentes esp?cies. Objetiva-se com este
trabalho identificar o polimorfismo no gene da Leptina, as varia??es nas caracter?sticas
qualitativas e quantitativas da carne e da carca?a de caprinos e relacionar as varia??es das
caracter?sticas produtivas a poss?veis polimorfismos. Foram utilizados para a genotipagem 38
cabritos machos inteiros, sendo 21 Saanen e 17 Cruzados Saanen x Boer. Os gen?tipos para o
marcador foram identificados pela t?cnica de PCR-RFLP com base nos protocolos
padronizados para o SNP305. Foram isoladas amostras de DNA gen?mico a partir de
leuc?citos e amplificados por interm?dio da t?cnica de Rea??o em Cadeia de Polimerase
(PCR). A PCR gerou fragmentos de 94 pares de bases (pb) que foram digeridos pela enzima
Kpn2I, originando dois fragmentos de 75 (pb) e 19 (pb) para todos os indiv?duos analisados,
obtendo frequ?ncia al?lica de 100% para o gen?tipo T. Dessa forma, n?o foi poss?vel
correlacionar os resultados obtidos na avalia??o de qualidade de carne e carca?a aos
resultados obtidos no estudo molecular. Para a avalia??o de qualidade de carca?a e carne
foram utilizados 18 machos inteiros, 9 Saanen e 9 Cruzados Saanen x Boer. Foi aplicado o
teste t para amostras independentes do programa estat?stico BioEstat a 5% de signific?ncia
(P<0,05) para as medidas morfom?tricas, peso vivo, peso vivo ap?s jejum, peso de carca?a
quente, peso de carca?a fria, quebra de resfriamento, rendimentos de carca?a, perda por
resfriamento, espessura de gordura de cobertura, cor, pH, capacidade de reten??o de ?gua e
maciez da carne, peso e rendimento de cortes (paleta, serrote, carr?, pernil e lombo) e ?ndice
de compacidade da carca?a. O grupamento dos animais Cruzados apresentou diferen?as
significativas (P<0,05) para largura de pernil e for?a de cisalhamento. Para os animais
Saanen, houve diferen?a significativa (P<0,05) para o comprimento externo da carca?a.
Embora os Cruzados tenham apresentado maiores valores de for?a de cisalhamento (P<0,05),
os dois grupos obtiveram m?dias abaixo de 5,4 kg-f cm-2, o que caracteriza carnes macias em
caprinos (2,20 e 1,57 kg-f cm-2 para Cruzados e Saanen, respectivamente). Os resultados
mostraram que a utiliza??o tanto dos animais Cruzados, quanto dos animais Saanen s?o uma
op??o vi?vel aos produtores de leite que desejam diversificar as atividades, aproveitando os
cabritos machos de descarte para a produ??o de carne
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Risco nas passagens de nível ferroviárias: lições do caso do acidente de Americana-SP / Risk on railway grade crossings: lessons from accident case of AmericanaSPLopes, Manoela Gomes Reis 16 March 2012 (has links)
Introdução - O cruzamento do modal ferroviário com rodoviário em um mesmo nível é chamado de passagem de nível (PN), os quais apresentam baixa freqüência de acidentes, porém elevados índices de gravidade. No dia 08 de setembro de 2010, em Americana-SP, ocorreu acidente envolvendo dois trens e um ônibus em uma PN, com dez vítimas fatais e dezessete feridos, dos quais quatro foram registrados como acidentes de trabalho. Objetivo - Analisar origens imediatas e latentes desse acidente visando evitar ou minimizar as chances de ocorrência de eventos semelhante no futuro. Método - Estudo de caso que foi realizado através da pesquisa de artigos, livros, jornais e reportagens televisivas sobre o assunto. Após essa etapa, foram realizadas entrevistas com pessoas envolvidas no acidente, como canceleiros, motoristas de ônibus e maquinistas. O Modelo de Análise e Prevenção de Acidentes de Trabalho (MAPA), que propõe uma abordagem sistêmica do caso, foi usado na análise do evento. Resultados - O local é mal iluminado e com presença de construções que dificultam a visualização dos trens. Essa PN apresenta intenso tráfego de pedestres e de carros mesmo com o sinal fechado. O motorista informou que o sinal vermelho só foi acionado quando o ônibus já estava no meio da PN, instantes antes do choque. As condições de trabalho dos motoristas de ônibus e maquinistas são inadequadas com uma prática freqüente de horas extras e às vezes não é respeitado o intervalo legal de 11 horas entre uma jornada e outra. As barreiras presentes na PN eram apenas simbólicas. O sistema de comunicação entre canceleiros, motoristas e maquinistas é dependente da ação humana sendo considerado frágil. Os entrevistados afirmaram já ter presenciado acidentes em PN, confirmando a fragilidade do sistema. O acidente foi investigado pelo Instituto de Criminalística que considerou o motorista do ônibus culpado pela ocorrência, sendo atualmente objeto de processo criminal correndo o risco de ser condenado e preso. Conclusão - O acidente foi um evento complexo, com a interação entre, pelo menos os seguintes componentes: o sistema de transporte rodoviário urbano, com destaque para a ação do motorista do ônibus; o transporte ferroviário e o trabalho dos maquinistas dos trens; o sistema de controle da PN que envolve o trabalho dos canceleiros encarregados da sinalização de aproximação dos trens; a concepção, gestão e manutenção da segurança da PN, o sistema viário urbano que inclui a iluminação pública / Introduction - The railway crossing with the road on the same level is called Grade Crossing (GC), which present low incidence of accidents, however, when they happen, they usually present high rates of severity. On September 8th, 2010, in Americana-SP, there was an accident involving two trains and one bus on a GC, with ten people died and seventeen were injured, four of which were registered as work accident. Aim - To analyze the immediate and latent causes of the accident attempting to avoid or minimize the chances of similar events to happen in the future. Method Case study that was performed by means of research from articles, books, newspapers and TV reports about the subject. After this phase, interviews were carried out with people involved in the accident, like watchmen, bus drivers and train operators. The Model of Analysis and Prevention of Work Accidents (MAPA), which proposes a systemic approach of the event, was used as a guide. Results - The site is poorly lit and with the presence buildings that obstruct the visualization of the trains coming to it. This GC has intense traffic of pedestrians and cars when the traffic signal is closed. The driver said that the red traffic signal was only triggered when the bus was in the middle of GC, moments before the collision. The work conditions bus drivers and driver of train are inadequate with a frequent practice of overtime and sometimes not respected the legal range of 11 hours between one day and another. At the time the accident happened, there were only symbolic barriers. The system of communication among watchmen, bus drivers and train operators depends on the human action being considered weak. The people interviewed said they had seen accidents on GC, which confirmed the fragility of the system. The accident was investigated by the Institute of Forensic Science which has considered the bus driver guilty of the occurrence, nowadays being object of criminal procedure and may be condemned and arrested. Conclusion - The accident was a complex event, with the interaction among, at least: the system of urban road transport, especially the action of the bus driver; the rail transport and the work of trains operators; the control system of GC, that involves the work of watchmen that are responsible by traffic signal at the approaching of trains; those in charge of design, management and maintenance of safety issues in the GCs and those in charge of the urban road system that includes lighting
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Evaluation of the Institute of Transportation Engineers program for school pedestrian crossingHamadeh, Nabil S. 01 January 1976 (has links)
The Technical Council of the Institute of Transportation Engineers (ITE) developed a program f or school crossing protection. The intent of this thesis is to evaluate the ITE program within. the context of those programs developed by other agencies throughout the nation. Research materials were obtained from the appropriate Federal, state, local and other agencies through papers, articles, reports and correspondence. Upon the analysis of these sources, the ITE program was found to be deficient in several ways. Recommendations for modifying the program which are set forth herein include a revision of the ITE program including the school route map, clarification of technical terminology, incorporation of a sound criteria for selecting the appropriate protective devices and/or measures, establishing a priority system, deletion of portable school signs, identification of funding sources, and establishing additional warrants for the installation of traffic control devices.
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Les échanges de l'ombre : passages des services de renseignements suisse et alliés à travers la frontière de l'Arc jurassien 1939-1945 / Underground Exchanges. : Crossings by Swiss and Allied Intelligence Services of the Franco-Swiss Border along the Jura Mountains during World War IIRossé, Christian 30 September 2013 (has links)
Durant la période de l’Occupation de la France, la frontière franco-suisse est bien gardée par les Allemands, secondés par les douaniers français, et les Suisses. Ses franchissements sont sévèrement réglementés. Les autorisations sont délivrées au compte-goutte. Elle se veut une barrière hermétique pour lutter par exemple, du côté allemand, contre la fuite de prisonniers de guerre ou de gens persécutés, l’espionnage, le marché noir, et, du côté suisse, contre l’afflux de réfugiés clandestins et la contrebande. Elle est doublée d’une zone interdite, sur sol français, dans laquelle il faut montrer patte blanche pour circuler. En principe donc, l’espace à proximité de la frontière est supposé être un no man’s land mort, occupé uniquement par les sentinelles.Mais, dans la réalité, cet objectif est bien loin d’être atteint. L’espace de la frontière est le lieu d’une intense activité clandestine. L’élément clé en est le passeur. Ce dernier est généralement soutenu par les « by-standers », soit les frontaliers qui, sans franchir eux-mêmes la frontière, leur offrent une assistance logistique (hébergement, nourriture, …). Grâce à ces réseaux, une masse hétéroclite de personnes et de choses, voire d’animaux, franchissent la frontière dans les deux sens : réfugiés juifs, prisonniers de guerre français ou polonais, espions suisses et alliés, résistants et maquisards français, marchandises de tous genres, courrier, etc.La mission du Service de renseignements suisse (SR) est de fournir au commandant en chef de l’armée et à l’Etat-major général les informations dont ils ont besoin pour prendre leurs décisions. L’acquisition de l’information est en théorie la tâche des postes extérieurs répartis le long de la frontière, ainsi que des centrales de collecte. Parmi les différentes méthodes employées pour rassembler les renseignements figurent l’étude des rapports des attachés militaires à l’étranger, l’exploitation des lignes de renseignement, mais aussi l’envoi de l’autre côté de la frontière suisse d’agents en mission.Les bons résultats du SR obtenus entre 1940 et 1944 sont dus en grande partie à la collaboration mise en place, à tous les niveaux, avec les services de renseignement étrangers et les réseaux de résistance. La Suisse a en effet été choisie par bon nombre d’organisations alliées comme plaque-tournante pour leurs réseaux de renseignement. Les informations convergent de toute l’Europe vers les représentations diplomatiques établies en Suisse avant d’être transmises par celles-ci, via des postes émetteurs, à destination de Londres, Moscou ou Washington.Que ce soit au niveau du commandement du SR ou des postes extérieurs, les hommes de Roger Masson tirent avantage de ce flux et établissent un rapport de donnant-donnant avec les réseaux étrangers. En échange d’informations pouvant intéresser la défense nationale, ils organisent le franchissement de la frontière aux agents étrangers et laissent les agents de la communauté internationale du renseignement vaquer à leurs occupations en toute impunité sur le territoire helvétique.Le SR est parfaitement intégré dans la communauté internationale du renseignement établie sur le territoire suisse durant la Seconde Guerre mondiale. Sur le terrain, il partage ses agents et ses passeurs avec les réseaux étrangers. / The Franco-Swiss border was well guarded during the French occupation, on the one side by the Germans, seconded by the French customs and on the other, by the Swiss. Border crossings were strictly controlled and the border was supposed to be water-tight. The French side of the border was doubled by a first zone accessible only by special authorisation, and a second forbidden zone 1 to 3 km wide stretching along the frontier. In the minds of the German occupying forces, this corridor along the border was supposed to be a no man’s land in which only the border guards patrolled.This ideal was a long way from being the achieved, since the corridor was the scene of intense clandestine activity. The key player was the ‘passeur’ who smuggled across the border and who was usually assisted by by-standers, residents on both sides of the border-zone who did not cross the border themselves, but who supplied the logistical support of safe houses, food etc… Thanks to this network of smugglers and by-standers, a heterogeneous mass of people, objects and even animals crossed the border in both directions – French and Polish POWs, Jewish refugees, Allied airmen, Swiss and Allied spies, French resistance fighters, post, and all sorts of merchandise…The Swiss Intelligence Service (SR) was tasked with supplying the commander-in-chief and the AHQ with the information which would allow them to lead the army. The collection of information was in theory the task of the outposts spread along the border as well as of the central stations. Amongst the various methods used to collect the raw information – such as the questioning of travellers and deserters, the study of reports issued by Swiss military attachés abroad and the exploitation of intelligence lines– the SR sent agents on missions beyond the Swiss borders.Part of the mechanism which allowed the SR to be well informed between 1940 and 1944, was its collaboration at all levels with the foreign secret services and the resistance networks. In fact a number of Allied organisations chose Switzerland as the hub of their intelligence networks. Information converged from all over Europe towards the embassies and consulates established in Switzerland, and these in turn transmitted it via radio emitters from their delegations, or via clandestine ones, to London, Moscow or Washington.Whether it was at the level of the head of the SR, or of the listening posts, Roger Masson’s men took advantage of this flow and set up relationships on a give and take basis with the foreign networks. In exchange for information affecting the security of the nation, they organized the border crossings of foreign agents and of documents coming from abroad, and allowed the international intelligence community agents to go about their business with almost total impunity on Swiss soil.The SR was perfectly integrated into the international ‘intelligence community’ established on Swiss soil during World War II. In the field, it ‘shared’ its agents and smugglers with the foreign networks.
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Reliability Analysis of Degrading Uncertain Structures - with Applications to Fatigue and Fracture under Random LoadingBeck, Andre Teofilo January 2003 (has links)
In the thesis, the reliability analysis of structural components and structural details subject to random loading and random resistance degradation is addressed. The study concerns evaluation of the probability of failure due to an overload of a component or structural detail, in consideration of random (environmental) loads and their combination, uncertain resistance parameters, statistical and phenomenological uncertainty and random resistance degradation mechanisms. Special attention is devoted to resistance degradation, as it introduces an additional level of difficulty in the solution of time variant reliability problems. The importance of this study arrives from the ageing of existing infrastructure in a world wide scale and from the lack of standards and codes for the ongoing safety management of general structures past their original design lives. In this context, probabilistic-based risk assessment and reliability analysis provide a framework for the safety management of ageing structures in consideration of inherent load and resistance uncertainty, current state of the structure, further resistance degradation, periodic inspections, in the absence of past experience and on an individual basis. In particular, the critical problem of resistance degradation due to fatigue is addressed. The formal solution of time variant reliability problems involves integration of local crossing rates over a conditional failure domain boundary, over time and over random resistance variables. This solution becomes very difficult in the presence of resistance degradation, as crossing rates become time dependent, and the innermost integration over the failure domain boundary has to be repeated over time. Significant simplification is achieved when the order of integrations is changed, and crossing rates are first integrated over the random failure domain boundary and then over time. In the so-called ensemble crossing rate or Ensemble Up-crossing Rate (EUR) approximation, the arrival rate of the first crossing over a random barrier is approximated by the ensemble average of crossings. This approximation conflicts with the Poisson assumption of independence implied in the first passage failure model, making results unreliable and highly conservative. Despite significant simplification of the solution, little was known to date about the quality of the EUR approximation. In this thesis, a simulation procedure to obtain Poissonian estimates of the arrival rate of the first up-crossing over a random barrier is introduced. The procedure is used to predict the error of the EUR approximation. An error parameter is identified and error functions are constructed. Error estimates are used to correct original EUR failure probability results and to compare the EUR with other common simplifications of time variant reliability problems. It is found that EUR errors can be quite large even when failure probabilities are small, a result that goes against previous ideas. A barrier failure dominance concept is introduced, to characterize those problems where an up-crossing or overload failure is more likely to be caused by a small outcome of the resistance than by a large outcome of the load process. It is shown that large EUR errors are associated with barrier failure dominance, and that solutions which simplify the load part of the problem are more likely to be appropriate in this case. It is suggested that the notion of barrier failure dominance be used to identify the proper (simplified) solution method for a given problem. In this context, the EUR approximation is compared with Turkstra’s load combination rule and with the point-crossing formula. It is noted that in many practical structural engineering applications involving environmental loads like wind, waves or earthquakes, load process uncertainty is larger than resistance uncertainty. In these applications, barrier failure dominance in unlikely and EUR errors can be expected to be small. The reliability problem of fatigue and fracture under random loading is addressed in the thesis. A solution to the problem, based on the EUR approximation, is constructed. The problem is formulated by combining stochastic models of crack propagation with the first passage failure model. The solution involves evaluation of the evolution in time of crack size and resistance distributions, and provides a fresh random process-based approach to the problem. It also simplifies the optimization and planning of non-destructive periodic inspection strategies, which play a major role in the ongoing safety management of fatigue affected structures. It is shown how sensitivity coefficients of a simplified preliminary First Order Reliability solution can be used to characterize barrier failure dominance. In the fatigue and fracture reliability problem, barrier failure dominance can be caused by large variances of resistance or crack growth parameters. Barrier failure dominance caused by resistance parameters leads to problems where overload failure is an issue and where the simplified preliminary solution is likely to be accurate enough. Barrier failure dominance caused by crack growth parameters leads to highly non-linear problems, where critical crack growth dominates failure probabilities. Finally, in the absence of barrier failure dominance, overload failure is again the issue and the EUR approximation becomes not just appropriate but also accurate. The random process-based EUR solution of time-variant reliability problems developed and the concept of barrier failure dominance introduced in the thesis have broad applications in problems involving general forms of resistance degradation as well as in problems of random vibration of uncertain structures. / PhD Doctorate
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Detection of Driver Unawareness Based on Long- and Short-term Analysis of Driver Lane KeepingWigh, Fredrik January 2007 (has links)
<p>Many traffic accidents are caused by driver unawareness. This includes fatigue, drowsiness and distraction. In this thesis two systems are described that could be used to decrease the number of accidents. In the first part of this thesis a system using long-term information to warn drivers suffering from fatigue is developed. Three different versions with different criteria are evaluated. The systems are shown to handle more then 60% of the cases correctly.</p><p>The second part of this thesis examines the possibilities of developing a warning system based on the predicted time-to-lane crossing, TLC. A basic TLC model is implemented and evaluated. For short time periods before lane crossing this may offer adequate accuracy. However the accuracy is not good enough for the model to be used in a TLC based warning system to warn the driver of imminent lane departure.</p>
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Mathematical modelling and analysis of communication networks: transient characteristics of traffic processes and models for end-to-end delay and delay-jitterØsterbø, Olav January 2003 (has links)
<p>The first part of the thesis (Part I) is devoted to find methods to describe transient behaviour of traffic processes, where the main emphasis is put on the description and analysis of excess periods and excess volumes of quite general stochastic processes. By assuming that traffic changes on different time scales, the transient characteristics such as excess periods could be important measures to describe periods of congestion on a communication link and moreover, the corresponding excess volume will represent lost information during such periods. Although the results obtained are of rather general nature, they provide some rather fundamental insight into transient characteristics of traffic processes. The distributions of the length of excess periods may then be expressed it terms of some excess probabilities that are related to the minimum of the process in the time interval considered. Similar relationsfor the excess volumes are harder to obtain and require the joint probability of the arrived volume and the minimum of the process in the same time interval.</p>
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Exploring rates and patterns of variability in gene conversion and crossover in the human genome /Hellenthal, Garrett. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 130-133).
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