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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.
1

Computing the Cohomology Ring and Ext-Algebra of Group Algebras

Pawloski, Robert Michael January 2006 (has links)
This dissertation describes an algorithm and its implementation in the computer algebra system GAP for constructing the cohomology ring and Ext-algebra for certain group algebras kG. We compute in the Morita equivalent basic algebra B of kG and obtain the cohomology ring and Ext-algebra for the group algebra kG up to isomorphism. As this work is from a computational point of view, we consider the cohomology ring and Ext-algebra via projective resolutions.There are two main methods for computing projective resolutions. One method uses linear algebra and the other method uses noncommutative Grobner basis theory. Both methods are implemented in GAP and results in terms of timings are given. To use the noncommutative Grobner basis theory, we have implemented and designed an alternative algorithm to the Buchberger algorithm when given a finite dimensional algebra in terms of a basis consisting of monomials in the generators of the algebra and action of generators on the basis.The group algebras we are mainly concerned with here are for simple groups in characteristic dividing the order of the group. We have computed the Ext-algebra and cohomology ring for a variety of simple groups to a given degree and have thus added many more examples to the few that have thus far been computed.
2

Uma introdução à Cohomologia local

Sousa, Wállace Mangueira de 20 December 2012 (has links)
Made available in DSpace on 2015-05-15T11:46:14Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 773765 bytes, checksum: b63ba4fb3ff15c5a4aef5a708fce596e (MD5) Previous issue date: 2012-12-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The goal this work is to understand the local cohomology functor, and some of its properties. We show that this functor has a relation with the functor Ext. Furthermore, we show the followings theorems: Grothendieck's Vanishing Theorem, Hartshorne's Vanishing Theorem, Grothendieck's Non-Vanishing Theorem and Hartshorne-Linchenbaum's Vanishing Theorem. / O objetivo desta dissertação é entender o funtor de Cohomologia Local, assim como algumas de suas propriedades. Mostramos que este funtor tem uma relação com o funtor Ext. Além disso, expomos os seguintes teoremas: Teorema do Anulamento de Grothendieck, Teorema do Anulamento de Hartshorne, Teorema do Não Anulamento de Grothendieck e o Teorema do Anulamento de Hartshorne-Linchtenbaum.
3

Structure of the space of extensions of barcodes / Strukturen hos mängden av utvidgningar av barcodes

Åkesson, Hugo January 2023 (has links)
Motivated by the recent development of noise systems, we try to describe, for fixed persistence modules \(X\) and \(Y\), the set of all persistence modules that are extensions of \(X\) by \(Y\), as well as their sizes. We restrict ourselves to tame persistence modules indexed by nonnegative numbers, and our notion of size is \((p,C)\)-norms, which is a generalization of \(p\)-norms. We prove that when \(X\) is a single bar, there is a monotone bijection between a set of antichains in the barcode of \(Y\) and the mentioned set of all extensions. A corollary is that the antichain consisting of maximal elements corresponds to the extension with maximal norm. Without this assumption on \(X\), we can reuse the previous result to construct a surjection from a set of tuples of antichains to the set of all extensions. We also conjecture that, with regards to this surjection, the tuple consisting of maximal antichains is mapped to the extension with maximal norm. We also provide some experimental justification for this conjecture. / Med anledning av det nyligen utvecklade begreppet noise system, försöker vi, för givna \(X\) och \(Y\), beskriva mängden av alla persistensmoduler som är utvidgningar av \(X\) med \(Y\), liksom deras storlekar. Vi begränsar oss till fallet med tama persistensmoduler, och där vi med storlek avser \((p,C)\)-normen, vilket är en generalisering av \(p\)-normen. I fallet när \(X\) består av en enda bar, konstruerar vi en monoton bijektion mellan en mängd av antikedjor och den nämnda mängden av alla utvidgningar. Ett korollarium är att antikedjan som består av maximala element motsvarar utvidgningen med störst norm. Vi använder sedan den nämnda bijektionen för att i det generella fallet konstruera en surjektion från en mängd av tuplar av antikedjor till mängden av alla utvidgningar. Vi formulerar även ett experimentellt bestyrkt påstående, nämligen att tupeln bestående av maximala antikedjor avbildas på utvidgningen med störst norm, av den nämnda surjektionen.
4

Representações irredutíveis de grau dois da primeira álgebra de Weyl / Irreducible representations the two deg of the first Weyl algebra

Duque, Cesar Augusto Rodriguez 27 November 2015 (has links)
Sejam K um corpo comutativo de caraterística zero. Definimos a álgebras associativa sobre K com dois geradores p, q onde pq qp = 1, como a primeira álgebra de Weyl, denotaremos esta por A 1 . As representações irredutíveis de grau um de dimensão infinita de A 1 , foram descritos por R. Block em (Block , 1981). Baseados nesta ideia, são descritas as represen- tações irredutíveis de grau dois de dimensão infinita de A 1 . No capítulo 1 são estudadas a representações da localização S 1 A 1 = B onde S = K[ q ] , ver (Block , 1981). Também apresentamos algumas definições e resultados relevantes para A 1 , os quais estabelecem uma relação entre as representações de álgebras de Lie nilpotente e as representações da enésima álgebra de Weyl A n , ver (Dixmier , 1959). No segundo capítulo é abordado o estudo da estrutura para A 1 -módulos de grau dois de dimensão infinita, obtendo uma descrição completa destes módulos. Usando esta estrutura é dada uma relação entre uma classe de Sl 2 -módulos de dimensão infinita e os A 1 -módulos de grau dois. Finalmente, no capítulo 3 são dados alguns fatos importares sobre a estrutura do Ext 1 (M, N ), onde M e N são A 1 -módulos irredutíveis de dimensão infinita com graus n 1 e n 2 repectivemente. / Let K be a commutative field such of zero characteristic. The associtive algebras from K whit two geradors p, q shuch that pq qp = 1 is the first Weyl algebra and it algebra going to denoted for A 1 . The structure of irreducible representations of degree one of infinite dimen- sional of A 1 , studied by R.Block (Block , 1981) on 1981. Based in this paper, we characterize the structure of degree two of irreducible representations of infinite dimensional of A 1 . In the first chapter, we speak of localization rings and defined B, we also give tools and definitions needed over Weyl algebras and nilpotent Lie algebras. In the second chapter we give the review for to the problem of A 1 -modules of degree two of infinite dimensional. At the end of the thesis we calculate the Ext 1 (M, N ), by M e N irreducibles A 1 -modules of degree n.
5

Appropriation de la compétence écrite de jeunes adultes malaisiens en milieu exolingue et endolingue pour une meilleure intégration dans un établissement supérieur français : problématique de l'écrit dans une situation d'apprentissage du FLE, difficultés liées à la reprise anaphorique et la reformulation de textes / The mastering of the written competency of young Malaysian adult learners of a target language in the ext-lingual and en train-lingual context with the aim of a better integration into a higher French institution of learning : issue of writing within

Ho, Lai Wan 07 December 2018 (has links)
Cette recherche vise à étudier deux procédés textuels : la reprise anaphorique et la reformulation textuelle, dans des écrits en FLE, produits par des étudiants Malaisiens à l'Institut de formation des formateurs de langues étrangères ou connu comme IPG KBA à Kuala Lumpur, Malaisie. La problématique générale s'inscrit dans le cadre de la didactique du texte écrit, relevant d'une linguistique textuelle qui permet de mieux comprendre la qualité du texte. Il s‟agit à la fois des caractéristiques observables à la surface du texte et des choix opérés pour construire et organiser la matière textuelle. La question fondamentale que nous nous sommes posée est de savoir comment aider les apprenants en FLE à se rendre compte de l'importance de l'articulation des deux niveaux local et global de l'organisation du texte, de sorte qu'ils arrivent à comprendre où se situent les dysfonctionnements dans leurs textes, de quels types de dysfonctionnements il s‟agit et de quelle manière ils peuvent y remédier. La méthodologie de recherche est basée sur une expérimentation auprès du public visé, conjuguant de facteurs textuels et extratextuels. L'analyse des textes d'apprenants a pour objectif de repérer, classer et interpréter les difficultés non seulement en fonction d'un cadre théorique d'analyse de textes mais en fonction d'une démarche comparative entre écrits d'un public en milieu d'apprentissage exolingue et celui d'endolingue. Les résultats atteints montrent que la sensibilisation des apprenants et le travail de réflexion avec eux, sur desf acteurs extratextuels, peuvent les aider à améliorer la qualité de leur production écrite. Il est aussi démontré qu‟en matière de connaissances textuelles, tout ce qui est intériorisé et maîtrisé en langue maternelle (langue première) et en anglais pourrait être exploitable de façon positive en français. Mais le français et l'anglais, deux langues étrangères, ne peuvent pas non plus être mises sur pied d'égalité, en ce qui concerne les difficultés rencontrées par les apprenants Malaisiens, du simple fait de leur « étrangeté ». Les propositions didactiques que nous avons suggérées s'inspirent de notre méthode d'analyse et reposent sur le souci d'améliorer la qualité de la production écrite en français chez le public allophone Malaisien. / This research aims at the study of two textual procedures notably the anaphoric rephrasing and the textual reformulation in the written texts in French as a Foreign Language, produced by the Malaysian students in the Institute of Teacher Training, International Languages Campus, Kuala Lumpur. The overall issue is embedded in the framework of the teaching of writing within the domain of textural linguistics. The latter enables us to understand better the quality of the text. This study deals with the observation of characteristics at the surface level as well as the choice of operations to construct and organise the textual matter. The fundamental question which confonts us is to know how to help foreign learners in French to be conscious of the importance of the global and local articulation of organising a text, leading to a better comprehension of where the textual defauts are situated. It's also more crucial to identify the types of defauts or textural disfonctionnings concerned and the remedial methods to these problems. The research methodology is based on an experiment conducted on a group of learners targetted, on a topic governed by the textual and extratextual factors. Analysis of the learners' written productions is for the objective of retrieving, regrouping and interpreting the difficulties from not only the theorical point of view but also responding to a comparative study between the written productions of a public in an exolingual and endolingual learning situations. The results achieved show that the consequences of writing on a topic bound byt he extratextual factors on the learners and the post-period of reflexion with them could help them in improving the quality of their written production. It attested also that the textual content knowledge and all that is interiorised and acquired in the first language as well as in English could be exploited in a positive way in French. However, French and English, two foreign languages cannot be put a long side equally when it comes to difficulties confronting the Malaysian learners, from the simple factual reason of their « alienicity ». The didactic propositions, which are suggested, are inspired by our method of analysis with the sole aim of improving the quality of written production in French among the Malaysian foreign learners of French.
6

Jämförelse av JavaScript-ramverk för stora dynamiska webbapplikationer / Comparison of JavaScript frameworks for large dynamic web applications

Lundgren, Victor January 2012 (has links)
På marknaden finns ett flertal JavaScript-ramverk, exempelvis: YUI, The Dojo Toolkit, Kendo UI och. Ext JS. Syftet med studien är att undersöka vilka av dessa JavaScript-ramverk som är lämpliga att använda vid utveckling av stora dynamiska webbapplikationer. Sedermera skall studien leda till ett förslag på JavaScript-ramverk för ändamålet. Ramverken har analyserats och jämförts med avseende på följande aspekter och kriterier: skalbarhet, prestanda, AJAX, RPC-hantering, licensering, webbläsarkompatibilitet, gränssnittskomponenter, anrop mellan domäner, DOM-hantering och användarvänlighet. För att jämföra och analysera ramverken har en testapplikation utvecklats med varje JavaScript-ramverk. Testapplikationen förses med information från en serverapplikation som utvecklats med PHP, där en SQLite-databas används som informationskälla. Förfarandet innebär att serverapplikationen inte används för att generera användargränssnittet, vilket därmed övergår till att vara JavaScript-ramverkets primära uppgift. Resultatet uppvisar att JavaScript-ramverket The Dojo Toolkit är karakteristiskt det mest lämpliga ramverket att använda i samband med utveckling av stora dynamiska webbapplikationer. Ramverket tillfredsställer samtliga kriterier och aspekter på ett eminent sätt. Sedermera föreslås Ext JS som det sekundära valet av JavaScript-ramverk för ändamålet. / On today’s market there are many attractive JavaScript-frameworks such as YUI, Dojo Toolkit, Kendo UI and Ext JS. The purpose with this study is to find JavaScript frameworks that are suitable in situation when developing large dynamic web applications. The study shall result in a proposal of one or more JavaScript frameworks to use in the situation previously described. The frameworks have been analyzed and compared with respect to the following aspects and criteria: scalability, AJAX, RPC-handling, cross-browser compatibility, GUI-components, cross-domain calls, DOM-handling, user-friendliness, performance, and licensing. To conduct this study a test application has been developed, that are developed with each framework. This application is feed with information from a database on a web server with PHP as the scripting environment. The application server’s primary objective is to provide information to the test application and not to generate the user interface. The result of this study indicates that Dojo Toolkit meets all requirements and has performed well overall. This framework satisfies the stated criteria and the specified aspects in an eminent way. It’s therefore proposed to be used as the main framework when developing large dynamic web applications. Ext JS is proposed as the secondary suggestion for the same purpose previously described.
7

Discipline-Independent Text Information Extraction from Heterogeneous Styled References Using Knowledge from the Web

Park, Sung Hee 11 July 2013 (has links)
In education and research, references play a key role. They give credit to prior works, and provide support for reviews, discussions, and arguments. The set of references attached to a publication can help describe that publication, can aid with its categorization and retrieval, can support bibliometric studies, and can guide interested readers and researchers. If suitably analyzed, that set can aid with the analysis of the publication itself, especially regarding all its citing passages. However, extracting and parsing references are difficult problems. One concern is that there are many styles of references, and identifying what style was employed is problematic, especially in heterogeneous collections of theses and dissertations, which cover many fields and disciplines, and where different styles may be used even in the same publication. We address these problems by drawing upon suitable knowledge found in the WWW. In particular, we use appropriate lists (e.g., of names, cities, and other types of entities). We use available information about the many reference styles found, in a type of reverse engineering. We use available references to guide machine learning. In particular, we research a two-stage classifier approach, with multi-class classification with respect to reference styles, and partially solve the problem of parsing surface representations of references. We describe empirical evidence for the effectiveness of our approach and plans for improvement of our method. / Ph. D.
8

A extensão universitária como instrumento de política pública / The academic extension as a tool for public policy

DINIZ, Flávio Pereira 27 March 2012 (has links)
Made available in DSpace on 2014-07-29T15:27:27Z (GMT). No. of bitstreams: 1 Flavio Pereira Diniz.pdf: 691928 bytes, checksum: 95066f9ce29e7a1301600c0ed10dfe07 (MD5) Previous issue date: 2012-03-27 / This work presents the results of an investigation, which had as its objective understand the building and development process of an academic extension conception defined and required as a potential instrument for social public policies. The information sources defined for the research were textual materials produced within the Brazilian Public Universities Extension Pro-Rectors Forum (EXPROFOR); documents from the Academic Extension Programme of Education Ministry (PROEXT/EM); texts from Extension Projects Methodology Seminar (EPMSEM) and reports of experiences presented on the Academic Extension Brazilian Congress (AEBC). The theoretical background comes from elements of Bakhtin s enunciation theory, highlighting this author s ideology and dialogism concepts. The results of the research indicate the existence of an imbrication between the guidelines elaborated by EXPROFOR and the financial policy of PROEXT/EM which, associated to the contributions in the methodological field and reports of extension experiences, elucidate the main characteristics of academic extension as an instrument of public policy. / Este trabalho apresenta os resultados de uma investigação que teve como objetivo compreender o processo de construção e desenvolvimento de uma determinada concepção de extensão universitária, definida e requerida como potencial instrumento de políticas públicas sociais. As fontes de informação definidas para a pesquisa foram materiais textuais produzidos no âmbito do Fórum de Pró-Reitores de Extensão das Universidades Públicas Brasileiras (FORPROEX), documentos do Programa de Extensão Universitária do Ministério da Educação (PROEXT/MEC), textos do Seminário de Metodologias para Projetos de Extensão (SEMPE) e relatos de experiências apresentados no Congresso Brasileiro de Extensão Universitária (CBEU). O aporte teórico e metodológico fundamenta-se em elementos da teoria da enunciação de Bakhtin, com destaque para os conceitos de ideologia e dialogismo neste autor. Nesta perspectiva, a contextualização e interposição dos materiais textuais pesquisados foram fundamentais para o êxito deste estudo. Os resultados da pesquisa indicam a existência de uma imbricação entre as diretrizes elaboradas pelo FORPROEX e a política de financiamento do PROEXT/MEC que, associada às contribuições no campo metodológico e relatos de experiências extensionistas, elucida as principais características daextensão universitária como instrumento de política pública.
9

Atividade anti-hiperglicemiante oral e segurança de uso do extrato aquoso da casca de Caesalpinia ferrea Martius Ex Tul (Leguminosae) em ratos Wistar

Fernando Brasileiro de Vasconcelos, Carlos 31 January 2011 (has links)
Made available in DSpace on 2014-06-12T16:28:29Z (GMT). No. of bitstreams: 2 arquivo6583_1.pdf: 2036261 bytes, checksum: 2f9456a9138bbf6c7d3482c028af1558 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / O diabetes mellitus é um grave problema de saúde pública caracterizado por hiperglicemia crônica ocasionada pela ausência ou ineficiência da insulina nos tecidos-alvo. Muitas espécies de plantas têm sido usadas na medicina popular para tratar os sintomas da doença. Na etnofarmacologia, o chá da casca de Caesalpinia ferrea Martius Ext Tul tem sido usado no tratamento do diabetes. Nesse estudo, metabólitos secundários foram identificados e quantificados por HPLC. A fim de verificar a atividade antidiabética de C. ferrea, quatro grupos de ratos Wistar diabéticos induzidos por estreptozotocina (50mg/Kg) (n=7/grupo) foram tratados com o extrato aquoso da casca do caule de C. ferrea (EaCf) (300 e 450mg/Kg/dia), veículo e metformina (500mg/Kg/dia) durante 4 semanas. Mudanças no ganho de massa, no consumo de água e ração e nos parâmetros bioquímicos foram avaliadas. A expressão da proteína quinase B (Akt), da proteína quinase ativada por AMP (AMPK) e acetil-CoA carboxilase (ACC) foram determinadas no fígado e músculo esquelético dos animais usando Western blot. A avaliação da segurança de uso do EaCf foi verificada através dos ensaios de toxicidade aguda, subcrônica, crônica e reprodutiva. Para os ensaios de toxicidade aguda, o EaCf (2000mg/Kg) foi administrado em ratos Wistar de ambos os sexos (n= 5/grupo/sexo). Na toxicidade subcrônica, ratos Wistar machos (n=10/grupo) foram tratados durante 30 dias com o EaCf (300 e 1500mg/Kg/dia) e na crônica, o EaCf (300 e 1500mg/Kg/dia) foi administrado aos camundongos Swiss machos durante 90 dias. Ao final do tratamento foram realizadas análises bioquímicas, hematológicas, macro e microscópicas dos órgãos. Na toxicidade reprodutiva, o EaCf (300 e 1500mg/Kg/dia) foi administrado em ratas Wistar prenhes durante o período integral de gestação para avaliação dos parâmetros reprodutivos maternos e comportamentais da prole. O conteúdo de ácido gálico, catequina, epicatequina e ácido elágico quantificado por HPLC foi de 112,76; 17,75; 6,13 e 12,00mg/g. Os resultados ainda mostraram que EaCf reduziu os níveis glicêmicos e melhorou o estado metabólico geral dos animais diabéticos. A ativação da Akt foi observada no fígado e músculo esquelético dos animais tratados com conseqüente desativação da AMPK no músculo e ativação da ACC em ambos quando comparado aos não-tratados. Na toxicidade aguda, o tratamento não induziu nenhum sinal de toxicidade ou morte, e na subcrônica, não houve alterações macro e microscópicas dos órgãos e nem nos parâmetros hematológicos e bioquímicos, exceto a amilasemia observada. Na toxicidade crônica, houve reduções no ganho de massa corporal, nos níveis séricos de proteínas totais e albumina (em ambas as doses). Na dose de 1500mg/Kg, houve aumento da lactato desidrogenase, amilase e necrose do intestino delgado. Durante toda a gestação, houve redução no ganho de massa corporal (1500mg/Kg) e na prole foram observadas reduções na massa corporal no 1º e 4º dias de vida e no comprimento, no 21º dia de vida pós-natal (1500mg/Kg). Os resultados sugerem que EaCf apresenta atividade antidiabética e age, possivelmente, regulando a captação hepática e muscular de glicose via Akt. O tratamento crônico sugere toxicidade principalmente na maior dose, provavelmente pela ação dos taninos que comprometem a absorção de macronutrientes
10

The Ext-Algebra of Standard Modules of Bound Twisted Double Incidence Algebras

Norlén Jäderberg, Mika January 2023 (has links)
Quasi-hereditary algebras are an important class of algebras with many appli-cations in representation theory, most notably the representation theory of semi-simple complex Lie-algebras. Such algebras sometimes admit an exact Borel sub-algebra, that is a subalgebra satisfying similar formal properties to the Borel sub-algebras from Lie theory. This thesis is divided into two parts. In the first part we classify quasi-hereditary algebras with two simple modules over perfect fields up to Morita equivalence, generalizing a similar result by Membrillo-Hernandez for thealgebraically closed case. In the second part, we take a poset X, a certain set M of constants, and a finite set ρ of paths in the Hasse-diagram of X and construct analgebra A(X, M, ρ) that generalizes the twisted double incidence algebras originally introduced by Deng and Xi. We provide necessary and sufficient conditions for this algebra to be quasi-hereditary when X is a tree, and we show that A(X, M, ρ) admits an exact Borel subalgebra when these conditions are satisfied. Following this, we compute the Ext-algebra of the standard modules of A(X, M, ρ).

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