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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.
31

Using Poisson processes for rare event simulation / De l'utilisation des processus de Poisson pour la simulation d'événements rares

Walter, Clément 21 October 2016 (has links)
Cette thèse est une contribution à la problématique de la simulation d'événements rares. A partir de l'étude des méthodes de Splitting, un nouveau cadre théorique est développé, indépendant de tout algorithme. Ce cadre, basé sur la définition d'un processus ponctuel associé à toute variable aléatoire réelle, permet de définir des estimateurs de probabilités, quantiles et moments sans aucune hypothèse sur la variable aléatoire. Le caractère artificiel du Splitting (sélection de seuils) disparaît et l'estimateur de la probabilité de dépasser un seuil est en fait un estimateur de la fonction de répartition jusqu'au seuil considéré. De plus, les estimateurs sont basés sur des processus ponctuels indépendants et identiquement distribués et permettent donc l'utilisation de machine de calcul massivement parallèle. Des algorithmes pratiques sont ainsi également proposés.Enfin l'utilisation de métamodèles est parfois nécessaire à cause d'un temps de calcul toujours trop important. Le cas de la modélisation par processus aléatoire est abordé. L'approche par processus ponctuel permet une estimation simplifiée de l'espérance et de la variance conditionnelles de la variable aléaoire résultante et définit un nouveau critère d'enrichissement SUR adapté aux événements rares / This thesis address the issue of extreme event simulation. From a original understanding of the Splitting methods, a new theoretical framework is proposed, regardless of any algorithm. This framework is based on a point process associated with any real-valued random variable and lets defined probability, quantile and moment estimators without any hypothesis on this random variable. The artificial selection of threshold in Splitting vanishes and the estimator of the probability of exceeding a threshold is indeed an estimator of the whole cumulative distribution function until the given threshold. These estimators are based on the simulation of independent and identically distributed replicas of the point process. So they allow for the use of massively parallel computer cluster. Suitable practical algorithms are thus proposed.Finally it can happen that these advanced statistics still require too much samples. In this context the computer code is considered as a random process with known distribution. The point process framework lets handle this additional source of uncertainty and estimate easily the conditional expectation and variance of the resulting random variable. It also defines new SUR enrichment criteria designed for extreme event probability estimation.
32

Termite Ectoparasitic Fungi in Japan: Distribution, Prevalence, and Molecular Detection / 日本におけるシロアリ外部寄生菌 : 分布、感染率および分子生物学的検出法

Ikhsan, Guswenrivo 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21156号 / 農博第2282号 / 新制||農||1059(附属図書館) / 学位論文||H30||N5130(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 吉村 剛, 教授 杉山 淳司, 教授 本田 与一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
33

Efficient and optimal designs for correlated observations

Chauhan, Nikhil January 2000 (has links)
No description available.
34

Pesquisa molecular de fungos patogênicos em quirópteros da região de Botucatu-SP

Paz, Giselle Souza da January 2017 (has links)
Orientador: Helio Langoni / Resumo: Atualmente dentre as doenças emergentes a maioria são zoonoses, e os morcegos desempenham papel importante como fonte de infecção e transmissão de agentes infecciosos. Histoplasmose e criptococose são doenças fúngicas relatadas em diversas espécies animais, podendo seus agentes serem isolados de grutas, cavernas, solo e fezes de animais. Paracoccidioidomicose, doença fúngica mais importante no Brasil, acomete principalmente populações de baixa renda, na zona rural e já foi relatada em animais silvestres e domésticos. Desta forma, o objetivo do presente estudo foi realizar a detecção molecular dos fungos Histoplasma capsulatum, Cryptococcus spp. e Paracoccidioides brasiliensis em quirópteros no município de Botucatu e região, SP. O delineamento do estudo foi de série de casos, a partir de morcegos recolhidos e enviados pela Vigilância Epidemiológica municipal de 12 cidades da região Centro-Oeste de São Paulo para o diagnóstico de raiva, no período de abril de 2015 a maio de 2016. Foram coletados pulmão, baço, fígado e intestino de 172 quirópteros, e avaliados pelas técnicas de nested-PCR e cultivo microbiológico. A prevalência encontrada para H. capsulatum foi de 8,14% (14/172), com um morcego positivo somente no cultivo microbiológico, 12 na técnica de nested-PCR, e um animal positivo em ambos os métodos. Dois morcegos foram positivos para Cryptococcus spp. e dois para P. brasiliensis pela técnica de nested-PCR. Como auxílio do software Autocad® foi realizado georreferenciame... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
35

Optimal Policy for Nested Task Interruptions in a Workflow Process

Haitham H. Saleh (5930219) 17 January 2019 (has links)
<div>Interruptions are the phenomena that exist and appear in many places in life; they appear everywhere in every kind of activities either in doing personal activities on a daily basis or in doing complicated activities and processes in complex systems in industries.</div><div><br></div><div>The role and the effect of interruptions have begun to appear a lot significantly in the industries in the last few years especially the ones that related to the task or job interruptions in businesses that affect directly to the flow process of the work. It is important to reference that the interruptions can be found in many different formats depending on the work environments. Interruptions are considered as a request for a change in process, job, think, direction, move or just for a short period of pause; these interruptions have the potential to carry treasured information that can allow people to control and manage activities in the incredibly dynamic environment successfully. This control obligation is universal in many different work environments ranging from office work to a more complicated and complex world of industries and businesses. Thus, interruptions have the potential for a tremendous positive impact on work success or the potential for a significant negative impact on work success. Industries hypothesize this interruption as a useful source of valuable information to improve the workplace and flow process. Increasing the frequency of interruptions can lead to increasing the magnitude of information obtainable from a highly dynamic activities environments.</div><div><br></div><div>Consequently, that leads to improving the coordination between people for the entire organization. However, this possible enhancement and improvement in performance and workflow process of work, utilizing the insight information from interruptions, has shown to be extremely problematic and challenging. The efficacy of the information attained from interruptions is relevant to the ongoing revolution of the workflow process. </div><div><br></div><div>In this dissertation, we divide the research study into two different phases. In the initial phase, we study the workflow process interruptions from the standpoint of human subject experimentation to understand, explore, comprehend, and exploit interruptions phenomena while doing a particular task. This phase leads us to comprehend and learn whether or not the workflow process interruptions affect on task performance, transitional lag time, interruption lag time, and resumption lag time regarding the range and the level of interruptions. We conduct experiments in two stages, and we use factorial designs in these experiments. In the second stage of this phase, we use the obtained information from the first stage to design the experiment for this stage. Subsequently, the experiment is complete and proposes new policy regulations for the workflow processes under the occurrence of the nested interruptions circumstances.</div><div><br></div><div>In the second phase of the dissertation, we study the workflow process interruptions from the standpoint of a simulation model. The apparent primary goal of this phase is to understand and comprehend the effect of the workflow process interruptions in the context of various policies. In this study, we compare, test, and evaluate the new proposed policy compared to the current practice of handling interruptions when nested interruptions exist and occur. As a result, the proposed policy improved the workflow process by a substantial and noticeable amount of time-saving in total completion time for the workflow process.</div>
36

Pesquisa molecular de fungos patogênicos em quirópteros da região de Botucatu-SP / Research molecular of pathogenic fungi in bats from Botucatu region

Paz, Giselle Souza da [UNESP] 16 February 2017 (has links)
Submitted by Giselle Souza da Paz null (giselle.spaz@yahoo.com.br) on 2017-02-24T03:10:34Z No. of bitstreams: 1 Dissertação.pdf: 1081711 bytes, checksum: 854b92b0e4655258cb81dd326f478bd5 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-03-02T18:12:52Z (GMT) No. of bitstreams: 1 paz_gs_me_bot.pdf: 1081711 bytes, checksum: 854b92b0e4655258cb81dd326f478bd5 (MD5) / Made available in DSpace on 2017-03-02T18:12:52Z (GMT). No. of bitstreams: 1 paz_gs_me_bot.pdf: 1081711 bytes, checksum: 854b92b0e4655258cb81dd326f478bd5 (MD5) Previous issue date: 2017-02-16 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Atualmente dentre as doenças emergentes a maioria são zoonoses, e os morcegos desempenham papel importante como fonte de infecção e transmissão de agentes infecciosos. Histoplasmose e criptococose são doenças fúngicas relatadas em diversas espécies animais, podendo seus agentes serem isolados de grutas, cavernas, solo e fezes de animais. Paracoccidioidomicose, doença fúngica mais importante no Brasil, acomete principalmente populações de baixa renda, na zona rural e já foi relatada em animais silvestres e domésticos. Desta forma, o objetivo do presente estudo foi realizar a detecção molecular dos fungos Histoplasma capsulatum, Cryptococcus spp. e Paracoccidioides brasiliensis em quirópteros no município de Botucatu e região, SP. O delineamento do estudo foi de série de casos, a partir de morcegos recolhidos e enviados pela Vigilância Epidemiológica municipal de 12 cidades da região Centro-Oeste de São Paulo para o diagnóstico de raiva, no período de abril de 2015 a maio de 2016. Foram coletados pulmão, baço, fígado e intestino de 172 quirópteros, e avaliados pelas técnicas de nested-PCR e cultivo microbiológico. A prevalência encontrada para H. capsulatum foi de 8,14% (14/172), com um morcego positivo somente no cultivo microbiológico, 12 na técnica de nested-PCR, e um animal positivo em ambos os métodos. Dois morcegos foram positivos para Cryptococcus spp. e dois para P. brasiliensis pela técnica de nested-PCR. Como auxílio do software Autocad® foi realizado georreferenciamento dos pontos de recolhimento dos animais, verificando quirópteros positivos em escolas, praças, residências e hospitais. Conclui-se que a presença de morcegos positivos para fungos patogênicos em áreas urbanas, é um risco para a saúde pública, visto que estes animais podem favorecer a manutenção e transmissão de patógenos em ambientes caseiros. Medidas de manejo ambiental devem ser orientadas a população pelo Serviço de Vigilância Epidemiológica Municipal, visando diminuir a população de morcegos em ambientes domésticos e minimizar os riscos de transmissão de fungos patogênicos. / Currently, among the emerging diseases, most are zoonosis, and baths play an important role as source of infection and transmission of infectious agents. Histoplasmosis, criptococcosis and paracoccidioidomicosis are fungal diseases reported in several animal species, and their agents can be isolated in grottos, caverns, soils and feces of animals. Paracoccidioidomycosis, the most important fungal disease in Brazil, affects mainly low-income populations in rural areas and has been reported in wild and domestic animals. Thus, the objective of the present study was performing the molecular detection of the fungi Histoplasma capsulatum, Cryptococcus spp. and Paracoccidioides brasiliensis in bats from the city of Botucatu and region, state of São Paulo.The study was delineated with a series of cases, from bats collected and sent by the Municipal Epidemiologic Surveillance of 12 cities from the Midwest region of São Paulo for the rabies diagnosis, within the time period from April 2015 to May 2016. Lung, spleen, liver and intestine were collected from 172 bats and assessed by nested-PCR and microbiological cultive techniques.The prevalence found for H. capsulatum was 8.14% (14/172), with one positive bath only by culturing the fungus, 12 in the nested-PCR technique and a positive animal in both methods. Two bats were positive for Cryptococcus spp. and two for P. brasiliensis by nested-PCR. With the aid of Autocad® software, the georeferencing of the animals’collection spots was performed, verifying positive bats in schools, squares, residences and hospitals. We conclude that the presence of positive baths for pathogenic fungi in urban areas is a risk to public health, since these animals can help on the maintenance and transmission of pathogens in domestic environments. Environmental management measures must be conducted to the population by the Municipal Service of Epidemiologic Surveillance, with the purpose of decreasing the baths population in domestic environments and minimizing the risk of transmitting pathogenic fungi. / FAPESP: 2014/23234-0
37

Formulation of Error Structures Under Non-Orthogonal Situations

Seely, Justus Frandsen 01 May 1965 (has links)
To gain an appreciation or understanding for the title of this study we must first understand what the phrases "non-orthogonal" and "error structure" mean. With an understanding of these terms the title of this study will become clear. To obtain an understanding of the term non-orthogonal, consider an experiment where differing treatments are applied to groups of experi­mental units in order to observe the differential treatment responses. If an equal number of experimental units are in each group, then we say we have an orthogonal situation. This means that when equal numbers exist among the experimental units, that the variability associated with the individual sources of variation can be orthogonally partitioned, such that the sources of variability add to the total source of variation. However, if unequal numbers exist among the experimental units, then we say we have a non-orthogonal situation. This implies that we can no longer obtain a completely orthogonal partition, and that the sources of variability associated with the individual sources of variation do not add to the total source of variation. The phrase, error structure, can best be described with reference to the statistical technique known as the analysis of variance. For any typical analysis of variance, there exists a one to one correspondence between the mean squares and the recognized sources of variation in the underlying model.
38

A Structural Approach to Analogy

Mansour, Hormoz 01 November 1983 (has links)
There are multiple sorts of reasoning by analogy between two domains; the one with which we are concerned is a type of contextual analogy. The purpose of this paper is to see whether two domains that look analogous would be analogous in all aspects and contexts. To perform this, we analyse the domain according to different particularities. For each particularity or context we continue the analysis and search for another one within the same domain. In this way we create a kind of structure for the different domains. This sort of analysis is represented by frames and frames which are nested within each other. This paper describes this concept and an implemented system "MULTI_ANALOG", a limited example of knowledge-acquisition, problem solving, and automatic-acquisition based on this particular form of analogy namely structural analogy.
39

Epidemiological Features of natural Mycoplasma hyopneumoniae infection in pigs in Spain

Sibila Vidal, Marina 27 July 2004 (has links)
En aquesta Tesis, s'ha estudiat per una banda, 1) la dinàmica de infecció de Mycoplasma hyopneumoniae (M. hyopneumoniae) a nivell de granja i la seva relació amb els diferents sistemes de producció i 2) la correlació entre la detecció d'aquest patogen a diferents nivells del tracte respiratori (cavitat nasal, tonsil.la, i bronqui) amb la seroconversió, i presència de lesions macroscópiques i microscópiques suggestives de la Pneumònia Enzoòtica (PE) a nivell de casos clínics i nivell d'animals de camp. Del estudi de la dinàmica de infecció en vam concloure que característiques inherents de cada granja tenien un efecte molt important en el patró de circulació de M.hyopneumoniae. Fins i tot dins d'una mateixa granja, es podien trobar dinàmiques de infecció diferents entre diferents lots d'animals, repercutint en diferents graus i moments d'aparició de les lesions. A més a més, el tipus de producció utilitzat (1-2 llocs versus 3 llocs) també influenciava la dinàmica de infecció del patogen. Els resultats obtinguts en les granges en 3 llocs, clarament donen suport a la característica tardana aparició del complex respiratori porcí en els sistemes de producció en múltiples fases. De fet, la colonització en transició era menor i més tardana en els sistemes en 3 llocs comparats amb en 1-2 llocs. A més a més, en els sistemes de producció en múltiples fases, s'observava un increment molt brusc de la proporció d'animals infectats associat a brot respiratoris tardans.Malgrat que la infecció per M.hyopneumoniae es va detectar en totes les granges, aquest patogen no estava sempre involucrat en els problemes respiratoris observats. De fet, es van observar garnges infectades clínica i subclínicament per M.hyopneumoniae Aquest fet pot ser important en el moment de prendre decisions sobre les estratègies de prevenció i control de malalties. Els seroperfils no van resultar ser discriminatius per determinar el paper del agent en els problemes respiratoris observats. Els bacterioperfils van ser més útils per determinar el paper del patogen, ja que l'aparició de la simptomatologia clínica estava estretament lligada a un increment de la proporció d'animals infectats (basat en la detecció de M.hyopneumoniae en hisops nasals). Tot i no ser discriminatiu, la proporció d'animals seropositius va ser major també en les granges afectades clínicament que en les subclinicament. La seroconversió en front a aquest agent ha estat descrita com lenta, retardada i molt variable. Ens els estudis de camp presentats en aquesta Tesis, la seroconversió també va ser variable. Sembla ser, que la seroconversió estava més relacionada amb la detecció de M.hyopneumoniae en els hisops bronquials que en els nasal o tonsil.lars, i a la vegada amb el percentatge d'animals amb els hisops bronquials positius.Tal i com s'esperava, l'hisop bronquial va ser el millor en predir la presencia de lesions macroscópiques i microscópiques de PE coincidint amb els treball prèviament publicats. Sorprenentment, la proporció relativa de detecció de M.hyopneumoniae en hisops nasals va ser menor en l'estudi de camp que en l'estudi on les mostres de diagnòstic. La major proporció d'hisops positius en els animals de diagnòstic es podria explicar per: un increment de l'excreció de M. hyopneumoniae degut a situacions estressants (tal com el transport) o el increment de la multiplicació de les bactèries després d'unes hores de la mort de l'animal. Els resultats d'aquesta Tesis, han demostrat que M. hyopneumoniae es pot detectar en tonsil.la, on no hi ha cèl·lules epitelials. Malgrat el mostreig d'hisops tonsil.lar en animals vius es possible però molt laboriós, pot esdevenir un lloc de mostreig més adequat per monitorejar la infecció per M.hyopneumoniae a nivell de granja. Per altre banda, el resultats obtinguts, demostren que quan l'hisop bronchial és positiu, la probabilitat de tenir lesions macroscópiqes i microscópiques compatibles amb PE és alta. Tanmateix, la presencia d'aquestes lesions no sempre implica la detecció de M.hyopneumoniae en bronqui, ja que poden ser causades per altres patògens com pot ser SIV. / The research presented in this Thesis assessed 1) the dynamics of infection of M. hyopneumoniae at a herd level and its relationship with production systems and 2) its detection in three respiratory levels (nasal cavities, tonsil and bronchi), taking into account the presence of seroconversion and macroscopic and microscopic lung lesions suggestive of Enzootic Pneumonia (EP)The studies on infection dynamics showed that the factor with greatest effect on M. hyopneumoniae circulation pattern was the farm. Even within a farm, significant differences in the dynamics of infection between different batches were observed, which were also related with different degrees and timings of M. hyopneumoniae -related lesions appearance.Moreover, the type of production system (1/2-site versus 3-site herds) was another factor that influenced M.hyopneumoniae infection dynamics. Results of our field trial in regards M.hyopneumoniae, involving 12 Spanish herds clearly support the characteristic late appearance of Porcine Respiratory Disease Complex (PRDC) in multisite production systems. M. hyopneumoniae colonization in nurseries was lower and occurred later in time in 3-site versus in 1/2-site production systems. Moreover, an abrupt increase in the proportion of infected animals, associated with late respiratory outbreaks was seen in the multisite production systems. Although M. hyopneumoniae infection was detected in all farms, it was not always involved in the respiratory disease. An important contribution of this work is that, although seroconversion and M. hyopneumoniae infection were detected in all herds, clinical and subclinical infections were described. This is important for decision making on the control strategies to implement at the farm. Serumprofiles were not discriminative to determine the involvement of M. hyopneumoniae in a clinical outbreak. Bacteriumprofiles were more useful in determining M. hyopneumoniae involvement in respiratory disease, since an increase of the proportion of infected pigs (based on detection of M. hyopneumoniae in nasal swabs) was clearly related with appearance of the clinical outbreak. Although not discriminative, the proportion of seropositive pigs was also greater in clinically than in subclinically infected herds. Dynamics of serocoversion against M. hyopneumoniae was another issue addressed in both, transversal and longitudinal field trials. Several authors have described the time of seroconversion under field conditions as slow, delayed and vaery variable. In field studies presented here time of seroconversion was also variable. Seroconversion was more related to detection of M. hyopneumoniae in bronchial swabs rather than in nasal or tonsillar swabs, and to the detection of a higher percentage of pigs with a positive nPCR bronchial swab. As expected, bronchial swabs were the best predictors of presence of microscopic and gross EP lesions coinciding with previously published studies. However, to sample bronchial swabs from live animals is not possible. Surprisingly, the relative proportion of nasal detection was lower in the field study than in the study using pigs received at the diagnostic laboratory. An increase of M.hyopneumoniae shedding in nasal cavities due to stressful situations (such as transport) or due to increase multiplication of bacteria after the animal's death have been proposed as potential explanations for a larger proportion nPCR positive nasal samples obtained in diagnostic samples.Results of this study demonstrated that detection of M.hyopneumoniae in tonsil where no ciliated epithelial cells exists, is possible. Although tonsillar sampling in live animals is more laborious than nasal samplings, it is possibly more adequate to monitor M. hyopneumoniae detection at a farm level. Results obtained in this Thesis and from previous works, showed that when bronchial swabs are positive the probability to show EP-compatible microscopic lesions in the animal is high. However, presence of EP-compatible lesions does not always imply M. hyopneumoniae detection in bronchi, and that may be caused by other pathogens such as SIV.
40

How expressive voting behavior affects candidates¡¦ positions

Wang, Shu-Cheng 26 July 2011 (has links)
We follow the approach of expressive voting and consider that voters with more extreme ideology can enjoy higher utility after voting. However, along with effect of ideology, voters also take the difference of his ideology and candidate¡¦s into account. Given the above assumptions, two candidates choose their ideology before voters decide whether and for whom to vote. Two candidates¡¦ ideology converges to the middle point if voters¡¦ utility generated by expressive voting approach is less important than by instrumental voting approach. In the opposite, two candidates¡¦ ideology diverge and the voters with mild ideology refuse to vote in point if voters¡¦ utility generated by expressive voting approach is more important. We examine the ANES data of ten U.S. presidential elections from 1972 to 2008. The nested logit model is used to estimate the corresponding coefficients of voters¡¦ utility generated by expressive voting approach and instrumental voting approach. The data supports our conjecture that voters with more extreme ideology are more likely to cast their votes.

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