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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.
131

Level of UV-B Radiation Influences the Effects of Glyphosate-Based Herbicide on Fitness of the Spotted Salamander

Levis, Nicholas A. 01 May 2014 (has links)
Numerous causes have been implicated in contributing to amphibian population declines since the 1980's, with habitat modification, ultraviolet radiation (UV-B) and environmental contaminants (such as glyphosate-based herbicide) being among the most common. This study identifies the effects of a generic glyphosate-based herbicide (GLY- 4 Plus) on mortality, immune function, body condition, and morphological plasticity of larvae of the spotted salamander (Ambystoma maculatum) under conditions that reflect open and closed canopy light regimes. Larval salamander responses to glyphosate-based herbicide varied depending on UV-B conditions. In general, it appears that an open canopy (i.e. greater UV-B exposure) may confer fitness benefits. In the presence of herbicide, survival was higher in an open canopy UV-B regime and pooled open canopy survival was higher than that of closed canopy treatments. In the absence of herbicide, body condition and immune function were positively related with amount of UV-B. Finally, herbicide presence appeared to affect morphology under low UV-B conditions. UV-induced breakdown of surfactant or a complex interaction between temperature stratification and trophic relations is potentially responsible for the observed patterns in survival and body condition. However, the mechanistic underpinnings of improved immune function and morphological differences are less clear. As deforestation is likely to continue, amphibians may find themselves in ponds with increasingly open canopies. Combined with the knowledge that some amphibians can become locally adapted to UV exposure and develop pesticide tolerance, the probability of surviving exposure to this herbicide may be elevated in open canopy ponds. These results emphasize the complexity of natural systems and the importance of including multiple factors in experiments.
132

Social Approaches to Disease Prediction

Mansouri, Mehrdad 25 November 2014 (has links)
Objective: This thesis focuses on design and evaluation of a disease prediction system that be able to detect hidden and upcoming diseases of an individual. Unlike previous works that has typically relied on precise medical examinations to extract symptoms and risk factors for computing probability of occurrence of a disease, the proposed disease prediction system is based on similar patterns of disease comorbidity in population and the individual to evaluate the risk of a disease. Methods: We combine three machine learning algorithms to construct the prediction system: an item based recommendation system, a Bayesian graphical model and a rule based recommender. We also propose multiple similarity measures for the recommendation system, each useful in a particular condition. We finally show how best values of parameters of the system can be derived from optimization of cost function and ROC curve. Results: A permutation test is designed to evaluate accuracy of the prediction system accurately. Results showed considerable advantage of the proposed system in compare to an item based recommendation system and improvements of prediction if system is trained for each specific gender and race. Conclusion: The proposed system has been shown to be a competent method in accurately identifying potential diseases in patients with multiple diseases, just based on their disease records. The procedure also contains novel soft computing and machine learning ideas that can be used in prediction problems. The proposed system has the possibility of using more complex datasets that include timeline of diseases, disease networks and social network. This makes it an even more capable platform for disease prediction. Hence, this thesis contributes to improvement of the disease prediction field. / Graduate / 0800 / 0766 / 0984 / mehrdadmansouri@yahoo.com
133

不盡相異物的環狀排列公式 / A Formula on Circular Permutation of Nondistinct Objects

王世勛, Wang,shyh shiun Unknown Date (has links)
n個物品之直線排列數與環狀排列數有對應關係,一般而言,具有K-循環節的直線排列之所有情形數若為 ,則 即為所對應的環狀排列數,亦即每K種直線排列對應到同一種環狀排列。本文將直線排列之所有情形依所具有的K-循環節之類別做分割,並導出具有K-循環節之直線排列之所有情形數之計數公式,假設直線排列依 -循環節, -循環節, , -循環節分類依序有 種不同排列情形,則所有的環狀排列數 。 / There exists a correspondence between ordered arrangements and circular permutations. Generally speaking, suppose the number of ordered arrangements with K-recurring periods is S, then the number of circular permutations is , namely we may assigne each K cases of ordered arrangements with K-recurring periods to a case of circular permutations. This article partitions the total cases of ordered arrangements with indistinguishable objects by means of the different catagories of K-recurring periods and derives a formula to calculate the total number of ordered arrangements with K-recurring periods. Suppose the number of ordered arrangements with -recurring periods、 -recurring periods、 、 -recurring periods is respectively, then the total number of circular permutations is .
134

A permutation evaluation of the robustness of a high-dimensional test

Eckerdal, Nils January 2018 (has links)
The present thesis is a study of the robustness and performance of a test applicable in the high-dimensional context (𝑝>𝑛) whose components are unbiased statistics (U-statistics). This test (the U-test) has been shown to perform well under a variety of circumstances and can be adapted to any general linear hypothesis. However, the robustness of the test is largely unexplored. Here, a simulation study is performed, focusing particularly on violations of the assumptions the test is based on. For extended evaluation, the performance of the U-test is compared to its permutation counterpart. The simulations show that the U-test is robust, performing poorly only when the permutation test does so as well. It is also discussed that the U-test does not inevitably rest on the assumptions originally imposed on it.
135

On the Uncrossing Partial Order on Matchings

January 2018 (has links)
abstract: The uncrossing partially ordered set $P_n$ is defined on the set of matchings on $2n$ points on a circle represented with wires. The order relation is $\tau'\leq \tau$ in $P_n$ if and only if $\tau'$ is obtained by resolving a crossing of $\tau$. %This partial order has been studied by Alman-Lian-Tran, Huang-Wen-Xie, Kenyon, and Lam. %The posets $P_n$ emerged from studies of circular planar electrical networks. Circular planar electrical networks are finite weighted undirected graphs embedded into a disk, with boundary vertices and interior vertices. By Curtis-Ingerman-Morrow and de Verdi\`ere-Gitler-Vertigan, the electrical networks can be encoded with response matrices. By Lam the space of response matrices for electrical networks has a cell structure, and this cell structure can be described by the uncrossing partial orders. %Lam proves that the posets can be identified with dual Bruhat order on affine permutations of type $(n,2n)$. Using this identification, Lam proves the poset $\hat{P}_n$, the uncrossing poset $P_n$ with a unique minimum element $\hat{0}$ adjoined, is Eulerian. This thesis consists of two sets of results: (1) flag enumeration in intervals in the uncrossing poset $P_n$ and (2) cyclic sieving phenomenon on the set $P_n$. I identify elements in $P_n$ with affine permutations of type $(0,2n)$. %This identification enables us to explicitly describe the elements in $P_n$ with the elements in $\mathcal{MP}_n$. Using this identification, I adapt a technique in Reading for finding recursions for the cd-indices of intervals in Bruhat order of Coxeter groups to the uncrossing poset $P_n$. As a result, I produce recursions for the cd-indices of intervals in the uncrossing poset $P_n$. I also obtain a recursion for the ab-indices of intervals in the poset $\hat{P}_n$, the poset $P_n$ with a unique minimum $\hat0$ adjoined. %We define an induced subposet $\mathcal{MP}_n$ of the affine permutations under Bruhat order. Reiner-Stanton-White defined the cyclic sieving phenomenon (CSP) associated to a finite cyclic group action on a finite set and a polynomial. Sagan observed the CSP on the set of non-crossing matchings with the $q$-Catalan polynomial. Bowling-Liang presented similar results on the set of $k$-crossing matchings for $1\leq k \leq 3$. In this dissertation, I focus on the set of all matchings on $[2n]:=\{1,2,\dots,2n\}$. I find the number of matchings fixed by $\frac{2\pi}{d}$ rotations for $d|2n$. I then find the polynomial $X_n(q)$ such that the set of matchings together with $X_n(q)$ and the cyclic group of order $2n$ exhibits the CSP. / Dissertation/Thesis / Doctoral Dissertation Mathematics 2018
136

Equações polinomiais e matrizes circulantes

Oliveira Júnior, Pedro Jerônimo Simões de 10 July 2015 (has links)
Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-30T14:02:41Z No. of bitstreams: 1 arquivototal.pdf: 1530287 bytes, checksum: bd20f7e7a563f1aa0ad40d276bc400f9 (MD5) / Approved for entry into archive by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2017-08-30T14:19:18Z (GMT) No. of bitstreams: 1 arquivototal.pdf: 1530287 bytes, checksum: bd20f7e7a563f1aa0ad40d276bc400f9 (MD5) / Made available in DSpace on 2017-08-30T14:19:18Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1530287 bytes, checksum: bd20f7e7a563f1aa0ad40d276bc400f9 (MD5) Previous issue date: 2015-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we discuss the procedures for solving polynomials equations of degree n 4; n 2 N via circulant matrices, highlighting a new perspective to obtain the Cardano- Tartaglia formulae. This brings up a new look on connected subjects, including the elimination of the term of degree (n􀀀1) and the characterization of real polynomials with all real roots. The method is based on searching a circulant matrix whose characteristic polynomial is identical to the one with the same roots we desire to nd. This approach provides us a simple and uni ed method for all equations through degree four. / Neste trabalho abordamos via matrizes circulantes a resolução de equações polinomiais de grau n 4; n 2 N , destacando uma nova perspectiva para obtenção das fórmulas de Cardano-Tartaglia. Além disso, ele oportuniza uma nova maneira de olhar para questões conexas, incluindo a eliminação do termo de grau (n 􀀀 1) e a caracterização de equações reais com todas as raízes reais. O método é baseado na busca de uma matriz circulante cujo polinômio característico seja idêntico ao das raízes que queremos encontrar. Essa metodologia nos fornece um método simples e uni cado para todas equações até quarto grau.
137

Métodos heurísticos para a programação em flow shop permutacional com tempos de setup separados dos tempos de processamento e independentes da seqüência de tarefas / Heuristic methods for the permutation flow shop scheduling problem with separated, non-batch, and sequence-independent setup times

Thays Josyane Perassoli Boiko 11 June 2008 (has links)
Este trabalho dedica-se ao problema de programação em flow shop permutacional com tempos de setup separados dos tempos de processamento e independentes da seqüência de execução das tarefas com o objetivo de minimizar a duração total da programação (Makespan). Por intermédio de investigações realizadas sobre as características estruturais do problema de programação e sua solução, uma propriedade deste problema é apresentada. Esta propriedade, denominada \"Propriedade LBY\", considerando quaisquer duas tarefas adjacentes Ju e Jv (Ju imediatamente precede Jv) independentemente de suas posições na seqüência de tarefas, fornece, um limitante inferior do tempo de espera para a tarefa Jv entre o fim do seu processamento na máquina Mk e o início do seu processamento na máquina seguinte. Dois novos métodos heurísticos são desenvolvidos, com base na propriedade apresentada e no procedimento de inserção de tarefas dos conhecidos métodos N&M e NEH: um construtivo, denominado BMc; e, um melhorativo, denominado BMm. Os métodos heurísticos propostos são comparados com os métodos heurísticos melhorativos de Cao; Bedworth (1992) e Rajendran; Ziegler (1997), através de um grande número de problemas gerados aleatoriamente. Os tempos de processamento são distribuídos no intervalo [1, 99] e os tempos de setup nos intervalos de [1, 49], [1, 99], [51, 149] e [101, 199]. Os métodos são avaliados quanto à porcentagem de sucesso em obter a melhor solução, ao desvio relativo médio e o tempo médio de computação. Os resultados da experimentação computacional mostram a qualidade do método construtivo BMc e a melhor performance do método melhorativo BMm. Estes resultados são apresentados e discutidos. / This work addresses the permutation flow shop scheduling problem with separated, non-batch, and sequence-independent setup times with the objective of minimizing the total time to complete the schedule (Makespan). Following an investigation of problem structural characteristics and your solution a property of this scheduling problem is presented. This property, denoted by \"Property LBY\", given any two adjacent jobs Ju e Jv (Ju immediately precedes Jv), regardless of their position in the sequence of jobs, provides an lower bound of the waiting time for job Jv between the end of its operations on the machine Mk and the beginning on machine M(k+1). Two news heuristics methods are development, on the basis of the presented property and in the job insertion procedure of the known methods named N&M and NEH: one constructive, denote by BMc; and, one improvement, denote by BMm. The proposed heuristics methods are compared with the improvement heuristics methods of Cao; Bedworth (1992) and Rajendran; Ziegler (1997), by a large number of randomly generated problems. The processing time are sampled from a distribution ranging from [1, 99] and, the setup times are sampled from distributions ranging from [1, 49], [1, 99], [51, 149] and [101, 199]. The methods are evaluated by the percentage of success in find the best solution, the average relative deviation and the average computation time. The results of the computational investigation show the quality of the constructive heuristic method BMc and that the improvement heuristic method BMc outperforms all others. These results are presented and discussed.
138

Análise de alterações em fenômenos agroambientais utilizando o método de entropia de permutação

FERREIRA, Diego Vicente de Souza 18 February 2016 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-05-20T16:02:58Z No. of bitstreams: 1 Diego Vicente de Souza Ferreira.pdf: 4348458 bytes, checksum: d170ec08e8b19561b0eff75d6b69c040 (MD5) / Made available in DSpace on 2016-05-20T16:02:58Z (GMT). No. of bitstreams: 1 Diego Vicente de Souza Ferreira.pdf: 4348458 bytes, checksum: d170ec08e8b19561b0eff75d6b69c040 (MD5) Previous issue date: 2016-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we analyze the complexity of stream flow in the São Francisco River and hot-pixels detected in Amazonia, in order to evaluate the effects of human activity. Permutation entropy is employed which takes into account temporal causality by comparing consecutive values within the series. We also use this entropy method to analyze rainfall regime in Pernambuco, Brazil. For the São Francisco River, we analyze the influence of the Sobradinho dam construction on the hydrological regime. The results show that entropy of stream flow increases after the dam’s construction in 1979, which indicates more disordered and less predictable dynamics. For hot-pixels detected in Amazonia, the increase in entropy is related to severe droughts in 2005, 2007, and 2010. For temporal series of precipitation in Pernambuco, entropy values decrease with distance from the coast, indicating more predictability of monthly rainfall in the zona de mata and agreste regions, and less predictable rainfall dynamics in the sertão and vale do São Francisco regions. / Neste trabalho foi analisada a complexidade das séries temporais de vazão do rio São Francisco e de queimadas na Amazônia, para avaliar as alterações causadas pela atividade humana. Utilizou-se o método entropia de permutação (Permutation entropy) que incorpora a relação temporal entre os valores da série analisada, utilizando uma representação simbólica baseada na comparação dos valores consecutivos da série. Este método também foi usado para analisar regime de chuva de Pernambuco. Para a vazão do rio São Francisco avaliou se a influência da construção da barragem Sobradinho no regime hidrológico. Os resultados das análises da série temporal de vazão para o período 1929-2009 mostraram que a entropia aumentou depois da construção da barragem Sobradinho indicando uma dinâmica de vazão mais desordenada e menos previsível neste período. Os resultados obtidos para série temporal diária de queimadas detectadas na Amazônia durante o período 1999-2012, mostraram um aumento da entropia relacionado com secas que ocorreram em 2005, 2007 e 2010. Em relação aos dados de precipitação de Pernambuco, os valores da entropia de permutação diminuem com o aumento da distância das estações do litoral, indicando maior variabilidade e menor previsibilidade das chuvas mensais nas regiões próximas a zona da mata e agreste, e menor variabilidade e maior previsibilidade nas regiões próximas ao sertão e vale do São Francisco.
139

Permutações

CAMPOS JÚNIOR, Walfrido Siqueira 10 June 2014 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-29T14:53:15Z No. of bitstreams: 1 Walfrido Siqueira Campos Junior.pdf: 422142 bytes, checksum: a769780b0d11bc646f87ad7036267f6b (MD5) / Made available in DSpace on 2017-03-29T14:53:15Z (GMT). No. of bitstreams: 1 Walfrido Siqueira Campos Junior.pdf: 422142 bytes, checksum: a769780b0d11bc646f87ad7036267f6b (MD5) Previous issue date: 2014-06-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work consists of the presentation of a simple permutation, seen as function. This function is bijective, hence admits inverse (inverse permutation). The composition of this function with the same it is also bijective (composed permutation). We will also see the permutations with repetition, circular without repetition and repetition, beyond chaotic permutations, which are those in which no element occupies its original position. The work is also part of the de nition and presentation of a group of permutations consisting of 3 properties in which the composition of functions satisfy all of them. This is our highest goal. Still show the parity of the permutation, as well as their applications in cases of determinants. / Este trabalho consta da apresentação de uma permutação simples, vista na forma de função. Essa função é bijetora, portanto admite inversa (permutação inversa). A composição dessa função com ela mesma, também é bijetora (permutação composta). Veremos também as permutações com repetição, circulares sem repetição e com repetição, além das permutações caóticas, que são aquelas em que nenhum elemento ocupa sua posição inicial. O trabalho consta também da definição e apresentação de um Grupo das permutações que consiste em 3 propriedades na qual a composição das funções satisfazem todas elas. Esse e o nosso maior objetivo. Mostraremos ainda a paridade da permutação, bem como suas aplicações em casos de determinantes.
140

O teorema de enumeração de Polya, generalizações e aplicações / Polya's enmeration theorem, generalizations and applications

Bovo, Eduardo 29 April 2005 (has links)
Orientador: Jose Plinio de Oliveira Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-05T07:47:09Z (GMT). No. of bitstreams: 1 Bovo_Eduardo_M.pdf: 3427598 bytes, checksum: 757ebc9282f3c010e155c26ec46fb42a (MD5) Previous issue date: 2005 / Resumo: Neste trabalho são desenvolvidos conceitos algébricos, analíticos e combinatórios que culminam no Teorema de Enumeração de Pólya; bem como são fornecidas muitas de suas aplicações em enumeração de padrões (grafos, colorações geométricas, tipos e permutações, etc). Tal teorema clássico, que tem suas bases em Teoria dos Grupos, utiliza fundamentalmente o conceito de funções geradoras, o que permite grande generalidade e computabilidade de resultados. Finalmente são apresentadas algumas generalizações do resultado principal, aplicações destas e também uma importante interpretação probabilística / Abstract: In this dissertation we present algebraic, analytic and combinatorial results that are used to prove Polya's Enumeration Theorem. Applications to counting patterns (graphs, colourings, permutations, etc.) are given. This classical Theorem has its foundations on the theory of groups and uses, mainly, the concept of generating functions which allows great generality and computability of results. At the end some generalizations of the main theorem are given including applications and, aiso, an important probabilistic interpretation / Mestrado / Combinatoria Enumerativa / Mestre em Matemática Aplicada

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