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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

A computational classification of multivariate polynomials using symmetries and reductions

Sturtivant, Carl January 1983 (has links)
An examination of some properties that interrelate the computational complexities of evaluating multivariate polynomial functions is presented. The kind of relationship between polynomial functions that is studied takes the form of linear transformations of the arguments and results of a polynomial function that transform it into another such function. Such transformations are a generalisation of projection (a form of reduction in algebraic complexity first introduced by Valiant, whereby variables and constants are substituted for the arguments of a polynomial function in order to transform it into another polynomial function). In particular, two restricted forms of this generalised projection are considered: firstly, those that relate a polynomial function to itself, and secondly, those that are invertable. Call these symmetries and similarities, respectively. The structure of the set of symmetries of a polynomial function is explored, and the computationally useful members of the set identified; a technique for finding all such symmetries is presented. It is shown that polynomials related by similarity have "isomorphic" sets of symmetries, and this condition may be used as a criterion for similarity. Similarity of polynomial functions is shown to be an equivalence relation, and "similar polynomials" can be seen to possess closely comparable complexities. A fast probabilistic algorithm for finding the symmetries of a polynomial function is given. The symmetries of the determinant and of the permanent (which differs from the determinant only in that all of its monomials have coefficients of +1), and those of some other polynomials, are explicitly found using the above theory. Fast algorithms using linear algebra for evaluating the determinant are known, whereas evaluating the permanent is known to be a #p-complete problem, and is apparently intractable; the reasons for this are exposed. As an easy corollary it is shown that the permanent is not preserved by any bilinear product of matrices, in con'trast to the determinant which is preserved by matrix multiplication. The result of Marcus and Minc, that the determinant cannot be transformed into the permanent by substitution of linear combinations of variables for its arguments (i.e. the permanent and determinant are not similar), also follows as an easy corollary. The relationship between symmetries and ease of evaluation is discussed.
2

Computational Investigation and Parametric Study of Lateral Impact Behavior of Pressurized Pipelines

Dou, Yangqing 07 May 2016 (has links)
This thesis presents a computational study to examine lateral impact behavior of pressurized pipelines and to determine influence of internal pressure on the impact behaviors of pipelines. More than 300 numerical simulations were carried out on mild steel pipe models with different internal pressure levels and were struck at the mid-span and at the one quarter span positions. The computational results for the first time systematically revealed the effects of internal pressure, impact position, and outside diameter on the lateral impact behavior of the pipeline models. It inspects effects of important parameters such as the outside diameter and internal pressure. Quartic polynomial functions are applied to formulate the maximum crushing force (F), permanent displacement (W), and absorbed energy (E) of the pressurized pipelines during the impact problem. Response surfaces are plotted based on the generated quartic polynomial functions and the quality (accuracy) of those functions are verified through several techniques.
3

Singularidades no infinito de funções polinomiais / Singularities at infinity of polynomial functions

Ribeiro, Nilva Rodrigues 22 October 2012 (has links)
O principal objetivo desta tese é classificar as singularidades no infinito de polinômios em \'C POT. n\'. Aplicamos inicialmente o método utilizado por Siersma e Smeltink em [38], para classificar polinômios de grau 3 em \'C POT. 3\'. Este método consiste em classificar polinômios fixando uma forma normal para a parte homogênea de maior grau. As singularidades no infinito de funções polinomiais podem ser estudadas através das singularidades das homogenizações destas aplicações definidas no espaço projetivo. Este é o método utilizado por Bruce e Wall em [11], que fazem uma classificação das superfícies cúbicas no espaço projetivo \'P POT. 3\', relacionando as singularidades destas superfícies com a classificação de certos sistemas polinomiais a elas associados. Um dos objetivos do nosso trabalho é estender parcialmente o método de Bruce e Wall para classificar as singularidades no infinito de polinomios f = \"f IND. d\'1 +\'f IND. d\' em \'C POT. n\', com d 3, através do estudo das singularidades do sistema polinomial g = (\'f IND. d\' 1, \'f IND. d\'). Para polinômios de grau 3 em \'C POT. 3\', fazemos um refinamento das formas normais de [11], que possibilita uma descrição mais detalhada da fibra especial e o estudo no infinito da topologia da fibra genérica. Isto é feito com o auxílio do invariante \' IND. n1\' (f) definido por Siersma e Tibar em [39], e por eles denominado defeito maximal de Betti / The main purpose of this thesis is to classify singularities at infinity of polynomial functions f : \'C POT. n\' C. We first apply Siersma and Smeltinks method [38] to classify degree 3 polynomials in \'C POT. 3\'. This method consists on classifying polynomials fixing the normal form of their highest homogeneous part. The singularities at infinity of polynomial functions may also be studied through the classification of singularities of the projective hypersurfaces F = 0, where F is the homogenization of f. This was the method applied by Bruce and Wall in [11], in their classification of the cubic surfaces in \'P POT. 3\'. They relate the singularities of the cubic surfaces with the singularities of certain systems of polynomials. In our work, we partially extend Bruce and Walls method to classify the singularities at infinity of polynomials f = \'f IND. d1\' + \'f IND. d\' in \'C POT. 3\', n 3, based on the investigation of singularities of the polynomial system g = (\'f IND. d1\', \'f IND. d\'). For the class of degree 3 polynomials in \'C POT. 3\', we refine Bruce-Walls classification, in order to present a more detailed description of the special fiber of f and to investigate its topology with the help of the invariant Betti maximal defect, introduced by Siersma and Tibar in [39]
4

Singularidades no infinito de funções polinomiais / Singularities at infinity of polynomial functions

Nilva Rodrigues Ribeiro 22 October 2012 (has links)
O principal objetivo desta tese é classificar as singularidades no infinito de polinômios em \'C POT. n\'. Aplicamos inicialmente o método utilizado por Siersma e Smeltink em [38], para classificar polinômios de grau 3 em \'C POT. 3\'. Este método consiste em classificar polinômios fixando uma forma normal para a parte homogênea de maior grau. As singularidades no infinito de funções polinomiais podem ser estudadas através das singularidades das homogenizações destas aplicações definidas no espaço projetivo. Este é o método utilizado por Bruce e Wall em [11], que fazem uma classificação das superfícies cúbicas no espaço projetivo \'P POT. 3\', relacionando as singularidades destas superfícies com a classificação de certos sistemas polinomiais a elas associados. Um dos objetivos do nosso trabalho é estender parcialmente o método de Bruce e Wall para classificar as singularidades no infinito de polinomios f = \"f IND. d\'1 +\'f IND. d\' em \'C POT. n\', com d 3, através do estudo das singularidades do sistema polinomial g = (\'f IND. d\' 1, \'f IND. d\'). Para polinômios de grau 3 em \'C POT. 3\', fazemos um refinamento das formas normais de [11], que possibilita uma descrição mais detalhada da fibra especial e o estudo no infinito da topologia da fibra genérica. Isto é feito com o auxílio do invariante \' IND. n1\' (f) definido por Siersma e Tibar em [39], e por eles denominado defeito maximal de Betti / The main purpose of this thesis is to classify singularities at infinity of polynomial functions f : \'C POT. n\' C. We first apply Siersma and Smeltinks method [38] to classify degree 3 polynomials in \'C POT. 3\'. This method consists on classifying polynomials fixing the normal form of their highest homogeneous part. The singularities at infinity of polynomial functions may also be studied through the classification of singularities of the projective hypersurfaces F = 0, where F is the homogenization of f. This was the method applied by Bruce and Wall in [11], in their classification of the cubic surfaces in \'P POT. 3\'. They relate the singularities of the cubic surfaces with the singularities of certain systems of polynomials. In our work, we partially extend Bruce and Walls method to classify the singularities at infinity of polynomials f = \'f IND. d1\' + \'f IND. d\' in \'C POT. 3\', n 3, based on the investigation of singularities of the polynomial system g = (\'f IND. d1\', \'f IND. d\'). For the class of degree 3 polynomials in \'C POT. 3\', we refine Bruce-Walls classification, in order to present a more detailed description of the special fiber of f and to investigate its topology with the help of the invariant Betti maximal defect, introduced by Siersma and Tibar in [39]
5

An Algorithmic Characterization Of Polynomial Functions Over Zpn

Guha, Ashwin 02 1900 (has links) (PDF)
The problem of polynomial representability of functions is central to many branches of mathematics. If the underlying set is a finite field, every function can be represented as a polynomial. In this thesis we consider polynomial representability over a special class of finite rings, namely, Zpn, where p is a prime and n is a positive integer. This problem has been studied in literature and the two notable results were given by Carlitz(1965) and Kempner(1921).While the Kempner’s method enumerates the set of distinct polynomial functions, Carlitz provides a necessary and sufficient condition for a function to be polynomial using Taylor series. Further, these results are existential in nature. The aim of this thesis is to provide an algorithmic characterization, given a prime p and a positive integer n, to determine whether a given function over Zpn is polynomially representable or not. Note that one can give an exhaustive search algorithm using the previous results. Our characterization involves describing the set of polynomial functions over Zpn with a ‘suitable’ generating set. We make use of this result to give an non-exhaustive algorithm to determine whether a given function over Zpn is polynomial representable.nβ
6

Piecewise polynomial functions on a planar region: boundary constraints and polyhedral subdivisions

McDonald, Terry Lynn 16 August 2006 (has links)
Splines are piecewise polynomial functions of a given order of smoothness r on a triangulated region (or polyhedrally subdivided region) of Rd. The set of splines of degree at most k forms a vector space Crk() Moreover, a nice way to study Cr k()is to embed n Rd+1, and form the cone b of with the origin. It turns out that the set of splines on b is a graded module Cr b() over the polynomial ring R[x1; : : : ; xd+1], and the dimension of Cr k() is the dimension o This dissertation follows the works of Billera and Rose, as well as Schenck and Stillman, who each approached the study of splines from the viewpoint of homological and commutative algebra. They both defined chain complexes of modules such that Cr(b) appeared as the top homology module. First, we analyze the effects of gluing planar simplicial complexes. Suppose 1, 2, and = 1 [ 2 are all planar simplicial complexes which triangulate pseudomanifolds. When 1 \ 2 is also a planar simplicial complex, we use the Mayer-Vietoris sequence to obtain a natural relationship between the spline modules Cr(b), Cr (c1), Cr(c2), and Cr( \ 1 \ 2). Next, given a simplicial complex , we study splines which also vanish on the boundary of. The set of all such splines is denoted by Cr(b). In this case, we will discover a formula relating the Hilbert polynomials of Cr(cb) and Cr (b). Finally, we consider splines which are defined on a polygonally subdivided region of the plane. By adding only edges to to form a simplicial subdivision , we will be able to find bounds for the dimensions of the vector spaces Cr k() for k 0. In particular, these bounds will be given in terms of the dimensions of the vector spaces Cr k() and geometrical data of both and . This dissertation concludes with some thoughts on future research questions and an appendix describing the Macaulay2 package SplineCode, which allows the study of the Hilbert polynomials of the spline modules.
7

Polinômio Interpolador de Lagrange: uma proposta para a melhoria do processo de ensino-aprendizagem de funções polinomiais e polinômios na Educação Básica

Lopes, Arthur Silva, 92981192212 25 May 2018 (has links)
Submitted by Juliana Tregnago (julianatregnago@gmail.com) on 2018-06-25T15:46:15Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Arthur.pdf: 1459378 bytes, checksum: cb0c9a3fddd8931c4664ce6f8635241b (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-06-26T13:04:00Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Arthur.pdf: 1459378 bytes, checksum: cb0c9a3fddd8931c4664ce6f8635241b (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-06-26T13:12:45Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Arthur.pdf: 1459378 bytes, checksum: cb0c9a3fddd8931c4664ce6f8635241b (MD5) / Made available in DSpace on 2018-06-26T13:12:46Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Arthur.pdf: 1459378 bytes, checksum: cb0c9a3fddd8931c4664ce6f8635241b (MD5) Previous issue date: 2018-05-25 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nowadays, the teaching of polynomial functions and polynomials is introduced with problems related to areas and perimeters of flat figures, volumes of geometric solids and the mention of some applications in other sciences, without showing the polynomial function used there. For a historical contextualization, the work is developed from the study of the improvement of Algebra throughout the societies. Then we will present the concepts of Polynomial in Rings and Fields, with some propositions, and the determinants, their properties, and the matrix of Vandermonde and its determinant. Promptly, we will talk about Interpolation, highlighting the polynomial interpolation. Finally, we present the panorama of Mathematics in Brazil and the proposal to use the Lagrange Interpolator Polynomial in the teaching of polynomial functions and the polynomials in basic education. / Atualmenteoensinodasfunçõespolinomiaisedospolinômioséintroduzidocomproblemasrelacionadosaáreaseperímetrosdefigurasplanas,avolumesdesólidosgeométricoseamenção de algumas aplicações em outras ciências, sem mostrar a função polinomial ali utilizada. Para umacontextualizaçãohistórica,otrabalhoédesenvolvidoapartirdoestudodoaperfeiçoamento da Álgebra ao longo das sociedades. Em seguida, apresentaremos os conceitos de Polinômio em Anéis e Corpos, com algumas proposições, e dos determinantes, suas propriedades, e a matriz de Vandermonde e seu determinante. Prontamente, falaremos sobre a Interpolação, destacando a interpolação polinomial. Finalmente, apresentaremos o panorama da Matemática no Brasil e a proposta de utilização do Polinômio Interpolador de Lagrange no ensino de funções polinomiais e dos polinômios na educação básica.
8

A probabilistic approach to a classical result of ore

Muhie, Seid Kassaw 31 August 2021 (has links)
The subgroup commutativity degree sd(G) of a finite group G was introduced almost ten years ago and deals with the number of commuting subgroups in the subgroups lattice L(G) of G. The extremal case sd(G) = 1 detects a class of groups classified by Iwasawa in 1941 (in fact sd(G) represents a probabilistic measure which allows us to understand how far is G from the groups of Iwasawa). Among them we have sd(G) = 1 when L(G) is distributive, that is, when G is cyclic. The characterization of a cyclic group by the distributivity of its lattice of subgroups is due to a classical result of Ore in 1938. Therefore sd(G) is strongly related to structural properties of L(G). Here we introduce a new notion of probability gsd(G) in which two arbitrary sublattices S(G) and T(G) of L(G) are involved simultaneously. In case S(G) = T(G) = L(G), we find exactly sd(G). Upper and lower bounds in terms of gsd(G) and sd(G) are among our main contributions, when the condition S(G) = T(G) = L(G) is removed. Then we investigate the problem of counting the pairs of commuting subgroups via an appropriate graph. Looking at the literature, we noted that a similar problem motivated the permutability graph of non–normal subgroups ΓN (G) in 1995, that is, the graph where all proper non– normal subgroups of G form the vertex set of ΓN (G) and two vertices H and K are joined if HK = KH. The graph ΓN (G) has been recently generalized via the notion of permutability graph of subgroups Γ(G), extending the vertex set to all proper subgroups of G and keeping the same criterion to join two vertices. We use gsd(G), in order to introduce the non–permutability graph of subgroups ΓL(G) ; its vertices are now given by the set L(G) − CL(G)(L(G)), where CL(G)(L(G)) is the smallest sublattice of L(G) containing all permutable subgroups of G, and we join two vertices H, K of ΓL(G) if HK 6= KH. We finally study some classical invariants for ΓL(G) and find numerical relations between the number of edges of ΓL(G) and gsd(G).
9

O USO DE JOGOS COMO ESTRATÉGIA DE ENSINO E APRENDIZAGEM DA MATEMÁTICA NO 1º ANO DO ENSINO MÉDIO

Strapason, Lísie Pippi Reis 30 September 2011 (has links)
Made available in DSpace on 2018-06-27T19:13:08Z (GMT). No. of bitstreams: 2 Lisie Pippi Reis Strapason.pdf: 15815936 bytes, checksum: acdbd264444719c7cb3c54be6fc19f80 (MD5) Lisie Pippi Reis Strapason.pdf.jpg: 3093 bytes, checksum: eb31814671a837cb2fa782245e5e80f5 (MD5) Previous issue date: 2011-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to find out whether the use of games as a teaching strategy to facilitate students learning concerning to the function concept and polynomial functions of the 1st and 2nd degrees. This research was accomplished with students in a class of 1 st year hight school that were applied in four games as a teaching and learning strategy. In the first game, was scheduled activities for the student to recognize the different representations of functions such as: writing; the numeric form, expressed through tables; visual, expressed by means of graphs; algebraic, represented by formulas; and using these differents representations to clarify the concept of function. In the second game, were developed different problem situations on polynomial function of the 1st degree. In the third game, was scheduled activities on the polynomial function of the 2nd degree and in the fourth game, were presented problem situations involving polynomial function of the 2nd degree in order to explore its properties. The research foccus is qualitative and the data analysis and interpretation of results were based on the theoretical and research objectives. The modality used for the research was the field search because data collection was carried out by the teacher and researcher through observations of students strategy during the games, noted in her field diary, and reports and work performed by them. From the results obtained we can concluded that the game was a good teaching strategy and facilitated the undestanding of the content worked. / Este trabalho teve como objetivo verificar se a utilização dos jogos como estratégia de ensino facilitou a aprendizagem dos alunos referente ao conceito de função e de funções polinomiais do 1º e do 2º graus. Esta pesquisa foi realizada com alunos de uma turma do 1º ano do Ensino Médio em que foram aplicados quatro jogos como estratégia de ensino e aprendizagem. No primeiro jogo, foram programadas atividades para o aluno reconhecer as diferentes representações de funções, tais como: a forma escrita; a forma numérica, expressa por meio de tabelas; visual, expressa por meio de gráficos; algébrica, representada por meio de fórmulas e que utilizasse essas diferentes representações para tornar mais claro o conceito de função. No segundo jogo, foram elaboradas diferentes situações-problema sobre a função polinomial de 1° grau. No terceiro jogo, foram programadas atividades sobre a função polinomial de 2º grau e, no quarto jogo, foram apresentadas situações-problema envolvendo a função polinomial do 2º grau com o propósito de explorar suas propriedades. A pesquisa teve uma abordagem qualitativa e a análise dos dados e a interpretação dos resultados foi embasada no referencial teórico e nos objetivos da pesquisa. A modalidade da pesquisa foi a de campo, pois a coleta de dados foi realizada pela professora e pesquisadora através das observações das estratégias dos alunos durante os jogos, anotadas em seu diário de campo, e dos trabalhos e relatos por eles realizados. Podemos concluir dos resultados obtidos que o jogo foi uma boa estratégia de ensino e facilitou a compreensão dos conteúdos trabalhados.
10

A formação de professores de matemática para uso das tecnologias de informação e comunicação: uma abordagem baseada no ensino de funções polinomiais de primeiro e segundo graus

Costa, Ricardo Carvalho 24 November 2010 (has links)
Made available in DSpace on 2016-04-27T16:57:03Z (GMT). No. of bitstreams: 1 Ricardo Carvalho Costa.pdf: 815443 bytes, checksum: e0237d33ddfc13d65730d8d76e2fb871 (MD5) Previous issue date: 2010-11-24 / Secretaria da Educação do Estado de São Paulo / This work refers to the research accomplished in the extent of the Didactic Workshops of Mathematical Education and Technologies; promoted by the group of researches TecMEM, of the Program of Postgraduate Studies in Mathematical Education of PUC/SP. The specific themes are the polynomial functions of first and second degrees, that were study object and discussion, on the part of teachers of Mathematics, that they teach in the first year of the Medium Teaching in schools of the public net of the State of São Paulo. The study tried to clean the possibilities and difficulties in the treatment with the content, mathematical specific and with the interfaces used computation, more specifically involving the software Winplot. Another objective was it of investigating, the elements considered by the teachers to the they elaborate, in groups, pedagogic strategies with the use of TICs, for eventual classes, that would give to their students on functions algebraic expressions. The analysis of the data allowed to identify some linked difficulties to the interpretation of statements, to the algebraic generalization, to the maintenance of expository practices on the part of the subject of the research, as well as concerning interesting possibilities to the experimentation and the dynamics of the educational practice of the same ones / Este trabalho refere-se à pesquisa realizada no âmbito das Oficinas Didáticas de Educação Matemática e Tecnologias, promovidas pelo grupo de pesquisas TecMEM do Programa de Estudos Pós-Graduados em Educação Matemática da PUC/SP. Os temas específicos da oficina a que se refere este trabalho são as funções polinomiais de primeiro e segundo graus, que foram objeto de estudo e discussão por parte de professores de Matemática que lecionam no primeiro ano do Ensino Médio em escolas da rede pública do Estado de São Paulo. O estudo procurou apurar as possibilidades e dificuldades no trato com o conteúdo matemático específico e com as interfaces computacionais utilizadas, mais especificamente envolvendo o software Winplot. Outro objetivo foi o de investigar os elementos considerados pelos professores ao elaborarem, em grupos, estratégias pedagógicas com o uso de TICs para eventuais aulas que dariam a seus alunos sobre funções polinomiais. A análise dos dados permitiu identificar algumas dificuldades ligadas à interpretação de enunciados, à generalização algébrica e à manutenção de práticas expositivas por parte dos sujeitos da pesquisa, bem como possibilidades interessantes atinentes à experimentação e à dinâmica da prática docente dos mesmos

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