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1
Pukhtaievych, Roman. « Periodic and hypercomplex potentials. Properties and applications ». Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425759.
Texte intégralRésumé :
This Dissertation is devoted to the study of boundary value problems and concerns two research areas. The first one is related to the perturbation analysis of boundary value problems in perforated domains and its application to the investigation of effective properties of composite materials. We investigate the dependence of the solutions of transmission boundary value problems upon some parameters and their behavior when the parameter corresponding to the size of the inclusions tends to zero, and the other parameters tend to some fixed values. Then we apply our results to study the effective conductivity of periodic composites. We also investigate the behavior of the solution of the Dirichlet problem for the Poisson equation in the domain in R3 which consists of a periodic array of cylinders upon perturbation of the shape of the cross-section of the cylinders and the periodic structure. Moreover, we apply our results to study the behavior of the longitudinal permeability of a periodic array of cylinders upon such perturbation. The second part of the Dissertation is related to the development of tools for solving boundary value problems for functions taking values in commutative Banach algebras. In particular, we investigate the properties of logarithmic residues of monogenic (continuous and differentiable in the sense of Gateau) functions and the behavior of the certain Cauchy type integral on the boundary of its definition.
The Dissertation consists of two parts and is organized as follows.
Part I consists of three chapters. In Chapter 1 we investigate the asymptotic behavior of the solutions of singularly perturbed (ideal and nonideal nonlinear) transmission problems in a periodically perforated domain. In Chapter 2 we apply the results of Chapter 1 to study the asymptotic behavior of the effective thermal conductivity of a periodic two-phase dilute composite. Chapter 3 is devoted to the study of the behavior of the longitudinal permeability of a periodic array of cylinders upon perturbation of the shape of the cross section of the cylinders and of the periodic structure.
Part II consists of two chapters. In Chapter 4 we introduce a three-dimensional commutative algebra over C with a one-dimensional radical and study the logarithmic residues of monogenic functions in this algebra. Chapter 5 is devoted to the investigation of a certain analog of Cauchy type integral taking values in the mentioned algebra and its limiting values on the boundary of the domain of definition. At the end of the Dissertation, we have enclosed three appendices with some results which we have exploited in the Dissertation.Questa Tesi si occupa dello studio di problemi al contorno e analizza due linee di ricerca. La prima riguarda lo studio di perturbazioni di problemi al contorno in domini perforati e la sua applicazione all'analisi delle proprieta efficaci dei materiali compositi. Studiamo la dipendenza delle soluzioni di problemi di trasmissione da alcuni parametri e il loro comportamento quando il parametro corrispondente alla dimensione delle inclusioni tende a zero e gli altri parametri tendono ad alcuni valori fissati. In seguito, applichiamo i nostri risultati allo studio della conduttivita efficace di composti periodici. Analizziamo anche il comportamento della soluzione del problema di Dirichlet per l'equazione di Poisson nell'insieme di R3 che consiste in una serie periodica di cilindri in caso di perturbazione della forma della sezione trasversale dei cilindri e la struttura periodica. Inoltre, applichiamo i nostri risultati per studiare il comportamento della permeabilita longitudinale di una serie periodica di cilindri rispetto a tale perturbazione. La seconda parte della Tesi riguarda lo sviluppo di strumenti per risolvere problemi al contorno per funzioni che assumono valore in algebre di Banach commutative. In particolare, studiamo le proprieta dei residui logaritmici delle funzioni monogeniche (continue e differenziabili nel senso di Gateaux) e il comportamento di certi integrali di tipo Cauchy sulla frontiera dell'insieme di definizione. La Tesi si suddivide in due parti ed è organizzata come segue. La parte I è composta da tre capitoli. Nel capitolo 1 studiamo il comportamento asintotico delle soluzioni di problemi di trasmissione (ideale e nonideale) singolarmente perturbati in un dominio periodicamente perforato. Nel capitolo 2 applichiamo i risultati del capitolo 1 per studiare il comportamento asintotico della conduttivita termica efficace di un composto periodico a due fasi diluito. Il capitolo 3 è dedicato allo studio del comportamento della permeabilita longitudinale di una serie periodica di cilindri quando perturbiamo la forma della sezione trasversale dei cilindri e la struttura periodica. La parte II è composta da due capitoli. Nel capitolo 4 introduciamo un'algebra commutativa tridimensionale su C con un radicale unidimensionale e studiamo i residui logaritmici delle funzioni monogeniche in questa algebra. Il capitolo 5 è dedicato allo studio di un analogo dell'integrale di Cauchy che assume valore nell'algebra menzionata e dei suoi valori limite sulla frontiera del dominio di definizione. Alla fine della Tesi, abbiamo inserito tre appendici con alcuni risultati che abbiamo utilizzato nella Tesi.
2
LEITE, LEONARDO DE SOUZA. « CONICS AND GRAPHS OF FUNCTIONS OF ONE VARIABLE ». PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26149@1.
Texte intégralRésumé :
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
O objetivo deste trabalho é apresentar conteúdos necessários para a construção de uma base sólida em Matemática do Ensino Fundamental e Médio, mas que são em geral mal assimilados pelos alunos. Inicialmente apresentaremos o plano cartesiano, equações de uma e duas variáveis, funções de uma variável real e gráfico de funções. Passaremos então ao estudo de curvas simples e bem conhecidas dos alunos em geral, como a circunferência, e chegaremos até as cônicas rotacionadas. A partir daí, procuramos relacionar as duas partes do trabalho, mostrando como as cônicas podem ser vistas como gráficos de função de uma variável. Pretende-se que este trabalho possa ser utilizado por professores do Ensino Fundamental e Médio em sala de aula, pois boa parte do conteúdo apresentado faz parte do currículo mínimo da Secretaria de Educação do Estado do Rio de Janeiro. Propomos atividades teóricas e computacionais, utilizando o software Geogebra para construção de curvas no plano cartesiano.
The objective of this paper is to present content needed to build a solid foundation in mathematics from primary and secondary schools, but are generally poorly assimilated by the students. Initially present the Cartesian plane, equations of one and two variables, functions of a real variable and function graph. Then we pass to the study of simple curves and well known to students in general, as the circumference, and arrive until the conical rotated. From there, we try to relate the two parts of the work, showing how the taper can be seen as a variable function graphs. It is intended that this work can be used by teachers of primary and secondary education in the classroom, because much of the content presented is part of the minimum curriculum of the Department of Education of the State of Rio de Janeiro. We propose theoretical and computational activities, using the Geogebra software to build curves in the Cartesian plane.
3
Balli, Umut. « Utility Accrual Real-Time Scheduling Under Variable Cost Functions ». Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/34358.
Texte intégralRésumé :
We present a utility accrual real-time scheduling algorithm called CIC-VCUA, for tasks whose
execution times are functions of their starting times. We model such variable execution times
employing variable cost functions (or VCFs). The algorithm considers application activities
that are subject to time/utility function time constraints (or TUFs), execution times de-
scribed using VCFs, and concurrent, mutually exclusive sharing of non-CPU resources. We
consider the multi-criteria scheduling objective of (1) assuring that the maximum interval
between any two consecutive, successful completions of jobs of a task must not exceed a
specified upper bound, and (2) maximizing the system's total accrued utility, while satis-
fying mutual exclusion resource constraints. Since the scheduling problem is intractable,
CIC-VCUA statically computes worst-case sojourn times of tasks, selects tasks for execution
based on their potential utility density, and completes them at specific times, in polynomial-
time. We establish that CIC-VCUA achieves optimal timeliness during under-loads. Further,
we identify the conditions under which timeliness assurances hold. Our simulation experi-
ments illustrate CIC-VCUA's effectiveness and superiority.Master of Science
4
Pettersson, Henrik Bengt. « Variable Stability Transfer Function Simulation ». Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/33503.
Texte intégralRésumé :
Simulation, whether in-flight or ground-based, is an invaluable tool for testing and
evaluating aircraft. Classically, a simulation model is specific to a single particular airframe,
only able to model those flying characteristics. Vast information can be gained from a
simulation that is able to model a wide range of aircraft, through a comparison of the
performance of these aircraft.
Such a variable stability simulation model was created based on 46 stability parame-ters,
including natural frequencies, damping ratios, time constants, and gains. The simula-tion
was obtained using transfer functions representing the aircraft state responses to control
inputs. These transfer functions were converted into state space systems used to create the
linear equations for the model.
The model was first developed as a desktop simulation and then converted for use
with the Virginia Techâ s 2F122A flight simulator. This conversion required a simple dynamic
inversion of the body axis force and moment terms. To reduce the error in these terms, a
model following scheme was incorporated.
A series of canned inputs and real-time pilot-in-the-loop tests were flown to evaluate
the variable stability model. Results in this paper have demonstrated the successful creation
of a variable stability simulation model.Master of Science
5
Oliveira, Ana Carolina de. « Quatérnios, operadores de Fueter e relações quaterniônicas transcendentais / ». São José do Rio Preto : [s.n.], 2006. http://hdl.handle.net/11449/94269.
Texte intégralRésumé :
Orientador: Manoel Ferreira Borges NetoBanca: Gilberto Aparecido Pratavieira
Banca: José Márcio Machado
Resumo: Resumo O objetivo deste trabalho é estabelecer similaridades entre os complexos e os hipercomplexos, motivados em explorar idéias de Murnaghan, que introduziu, pela primeira vez, em uma apresentação elementar, a teoria dos quatérnios baseados no teorema de Moivre. É mostrada em detalhes uma analogia da relação complexa clássica de Moivre para quatérnios, e em brevidade para octônios generalizados, e apresenta-se as conexões com os operadores da teoria de Fueter e as funções transcendentais. A extensão do teorema de Moivre é estudada para quatérnios em definindo-se uma função exponencial quaterniônica.
Abstract: Abstract In this work we establish similarities between the complex and the hipercomplex numbers, motivated in exploring ideas of Murnaghan, that introduced, for the first time, in an elementary presentation, the theory of the quaternions based on the theorem of Moivre. We show an analogy of the classic complex relation of Moivre for quaternions, and briefly discuss generalized octonions, as well as to present connections to operators of the theory of Fueter and transcendental functions. We consider them to study the extension of the theorem of Moivre for quaternions, in defining a exponential function on the quaternions.
Mestre
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Oliveira, Ana Carolina de [UNESP]. « Quatérnios, operadores de Fueter e relações quaterniônicas transcendentais ». Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/94269.
Texte intégralRésumé :
Made available in DSpace on 2014-06-11T19:26:56Z (GMT). No. of bitstreams: 0
Previous issue date: 2006-02-20Bitstream added on 2014-06-13T18:47:50Z : No. of bitstreams: 1
oliveira_ac_me_sjrp.pdf: 346640 bytes, checksum: dfe236f71e5ef2c050420d64d2c48a70 (MD5)O objetivo deste trabalho é estabelecer similaridades entre os complexos e os hipercomplexos, motivados em explorar idéias de Murnaghan, que introduziu, pela primeira vez, em uma apresentação elementar, a teoria dos quatérnios baseados no teorema de Moivre. É mostrada em detalhes uma analogia da relação complexa clássica de Moivre para quatérnios, e em brevidade para octônios generalizados, e apresenta-se as conexões com os operadores da teoria de Fueter e as funções transcendentais. A extensão do teorema de Moivre é estudada para quatérnios em definindo-se uma função exponencial quaterniônica.
In this work we establish similarities between the complex and the hipercomplex numbers, motivated in exploring ideas of Murnaghan, that introduced, for the first time, in an elementary presentation, the theory of the quaternions based on the theorem of Moivre. We show an analogy of the classic complex relation of Moivre for quaternions, and briefly discuss generalized octonions, as well as to present connections to operators of the theory of Fueter and transcendental functions. We consider them to study the extension of the theorem of Moivre for quaternions, in defining a exponential function on the quaternions.
7
Balister, P. N. « Two variable #rho#-adic L-functions for CM elliptic curves with supersingular reduction ». Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240890.
Texte intégral
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Braun, H. T. F. « Model theory of holomorphic functions ». Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401108.
Texte intégralRésumé :
This thesis is concerned with a conjecture of Zilber: that the complex field expanded with the exponential function should be `quasi-minimal'; that is, all its definable subsets should be countable or have countable complement. Our purpose is to study the geometry of this structure and other expansions by holomorphic functions of the complex field without having first to settle any number-theoretic problems, by treating all countable sets on an equal footing. We present axioms, modelled on those for a Zariski geometry, defining a non-first-order class of ``quasi-Zariski'' structures endowed with a dimension theory and a topology in which all countable sets are of dimension zero. We derive a quantifier elimination theorem, implying that members of the class are quasi-minimal. We look for analytic structures in this class. To an expansion of the complex field by entire holomorphic functions $\mathcal{R}$ we associate a sheaf $\mathcal{O}^{\scriptscriptstyle{\mathcal{R}}}$ of analytic germs which is closed under application of the implicit function theorem. We prove that $\mathcal{O}^{\scriptscriptstyle{\mathcal{R}}}$ is also closed under partial differentiation and that it admits Weierstrass preparation. The sheaf defines a subclass of the analytic sets which we call $\mathcal{R}$-analytic. We develop analytic geometry for this class proving a Nullstellensatz and other classical properties. We isolate a condition on the asymptotes of the varieties of certain functions in $\mathcal{R}$. If this condition is satisfied then the $\mathcal{R}$-analytic sets induce a quasi-Zariski structure under countable union. In the motivating case of the complex exponential we prove a low-dimensional case of the condition, towards the original conjecture.
9
Kakehashi, Shoji, Hiroshi Hasegawa, Ken-ichi Sato, Osamu Moriwaki et Shin Kamei. « Analysis and Development of Fixed and Variable Waveband MUX/DEMUX Utilizing AWG Routing Functions ». IEEE, 2009. http://hdl.handle.net/2237/14029.
Texte intégral
10
Ahmad, Khan Mumtaz, et Bahman Alidad. « Three Variable Analogue of Boas and Buck Type Generating Functions and Its Generalizations to M-Variables ». Pontificia Universidad Católica del Perú, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/97282.
Texte intégralRésumé :
The present papers deals with three variable analogue of Boas and Buck [14] type generating functions forpolynomials of two variables and then the same has been extended for m-variable analogue. The results obtained are extensions of those obtained by us in our earlier paper [14].El presente artículo trata el anólogo de tres variables de la función generatriz de Boas and Buck [14] para polinomios de dos variables y lo mismo se puede extender para el análogo de m variables. Los resultados obtenidos son extensiones de un artículo previo [14].
11
Manoharan, Madhu. « Evaluation of a neural network for formulating a semi-empirical variable kernel BRDF model ». Master's thesis, Mississippi State : Mississippi State University, 2005. http://library.msstate.edu/content/templates/?a=72.
Texte intégral
12
Cheng, Jiuyi. « Two problems in function theory of one complex variable : local properties of solutions of second-order differential equations and number of deficient functions of some entire functions ». Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/38553.
Texte intégral
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Slezak, Jonathan Michael. « Effects of variable training, signaled and unsignaled delays, and [delta]-amphetamine on delay-discounting functions obtained within session ». Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5650.
Texte intégralRésumé :
Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains vii, 52 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 44-48).
14
Cruz, Carla Maria. « Numerical and combinatorial applications of generalized Appell polynomials ». Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13962.
Texte intégralRésumé :
Doutoramento em MatemáticaThis thesis studies properties and applications of different generalized Appell polynomials in the framework of Clifford analysis. As an example of 3D-quasi-conformal mappings realized by generalized Appell polynomials, an analogue of the complex Joukowski transformation of order two is introduced. The consideration of a Pascal n-simplex with hypercomplex entries allows stressing the combinatorial relevance of hypercomplex Appell polynomials. The concept of totally regular variables and its relation to generalized Appell polynomials leads to the construction of new bases for the space of homogeneous holomorphic polynomials whose elements are all isomorphic to the integer powers of the complex variable. For this reason, such polynomials are called pseudo-complex powers (PCP). Different variants of them are subject of a detailed investigation. Special attention is paid to the numerical aspects of PCP. An efficient algorithm based on complex arithmetic is proposed for their implementation. In this context a brief survey on numerical methods for inverting Vandermonde matrices is presented and a modified algorithm is proposed which illustrates advantages of a special type of PCP. Finally, combinatorial applications of generalized Appell polynomials are emphasized. The explicit expression of the coefficients of a particular type of Appell polynomials and their relation to a Pascal simplex with hypercomplex entries are derived. The comparison of two types of 3D Appell polynomials leads to the detection of new trigonometric summation formulas and combinatorial identities of Riordan-Sofo type characterized by their expression in terms of central binomial coefficients.
Esta tese estuda propriedades e aplicações de diferentes polinómios de Appell generalizados no contexto da análise de Clifford. Exemplificando uma transformação realizada por polinómios de Appell generalizados, é introduzida uma transformação análoga à transformação de Joukowski complexa de ordem dois. A análise de um n- simplex de Pascal com entradas hipercomplexas permite sublinhar a relevância combinatória de polinómios hipercomplexos de Appell. O conceito de variáveis totalmente regulares e a sua relação com polinómios de Appell generalizados conduz à construção de novas bases para o espaço dos polinómios homogéneos holomorfos cujos elementos são todos isomorfos às potências inteiras da variável complexa. Por este motivo, tais polinómios são chamados de potências pseudo-complexas (PCP). Diferentes variantes de PCP são objeto de uma investigação detalhada. É dada especial atenção aos aspectos numéricos de PCP. Um algoritmo eficiente baseado em aritmética complexa é proposto para a sua implementação. Neste contexto, é apresentado um breve resumo de métodos numéricos para inverter matrizes de Vandermonde e é proposto um algoritmo modificado para ilustrar as vantagens de um tipo especial de PCP. Finalmente, são enfatizadas aplicações combinatórias de polinómios de Appell generalizados. A expressão explícita dos coeficientes de um tipo particular de polinómios de Appell e a sua relação com um simplex de Pascal com entradas hipercomplexas são obtidas. A comparação de dois tipos de polinómios de Appell tridimensionais leva à deteção de novas fórmulas envolvendo somas trigonométricas e de identidades combinatórias do tipo de Riordan – Sofo, caracterizadas pela sua expressão em termos de coeficientes binomiais centrais.
15
Kurpa, Lidiya, et T. Shmatko. « Investigation of Geometrically Nonlinear Vibrations of Laminated Shallow Shells with Layers of Variable Thickness by Meshless Approach ». Thesis, Точка, 2013. http://repository.kpi.kharkov.ua/handle/KhPI-Press/37086.
Texte intégralRésumé :
Geometrically nonlinear vibrations of laminated shallow shells with layers of variable thickness are studied.
Nonlinear equations of motion for shells based on the first order shear deformation and classical shells theories
are considered. In order to solve this problem we use the numerically-analytical method proposed in work [1].
Accordingly to this approach the initial problem is reduced to consequences of some linear problems including
linear vibrations problem, special elasticity ones and nonlinear system of ordinary differential equations in
time. The linear problems are solved by the variational Ritz’ method and Bubnov-Galerkin procedure combined
with the R-functions theory [2]. To construct the basic functions that satisfy all boundary conditions in case of
simply-supported shells we propose new solutions structures. The proposed method is used to solve both test
problems and new ones.
16
Remde, Stephen Mark. « Enhancing the performance of search heuristics : variable fitness functions and other methods to enhance heuristics for dynamic workforce scheduling ». Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4310.
Texte intégralRésumé :
Scheduling large real world problems is a complex process and finding high quality solutions is not a trivial task. In cooperation with Trimble MRM Ltd., who provide scheduling solutions for many large companies, a problem is identified and modelled. It is a general model which encapsulates several important scheduling, routing and resource allocation problems in literature. Many of the state-of-the-art heuristics for solve scheduling problems and indeed other problems require specialised heuristics tailored for the problem they are to solve. While these provide good solutions a lot of expert time is needed to study the problem, and implement solutions. This research investigates methods to enhance existing search based methods. We study hyperheuristic techniques as a general search based heuristic. Hyperheuristics raise the generality of the solution method by using a set of tools (low level heuristics) to work on the solution. These tools are problem specific and usually make small changes to the problem. It is the task of the hyperheuristic to determine which tool to use and when. Low level heuristics using exact/heuristic hybrid method are used in this thesis along with a new Tabu based hyperheuristic which decreases the amount of CPU time required to produce good quality solutions. We also develop and investigate the Variable Fitness Function approach, which provides a new way of enhancing most search-based heuristics in terms of solution quality. If a fitness function is pushing hard in a certain direction, a heuristic may ultimately fail because it cannot escape local minima. The Variable Fitness Function allows the fitness function to change over the search and use objective measures not used in the fitness calculation. The Variable Fitness Function and its ability to generalise are extensively tested in this thesis. The two aims of the thesis are achieved and the methods are analysed in depth. General conclusions and areas of future work are also identified.
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Remde, Stephen M. « Enhancing the Performance of Search Heuristics. Variable Fitness Functions and other Methods to Enhance Heuristics for Dynamic Workforce Scheduling ». Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4310.
Texte intégralRésumé :
Scheduling large real world problems is a complex process and finding high quality
solutions is not a trivial task. In cooperation with Trimble MRM Ltd., who provide
scheduling solutions for many large companies, a problem is identified and modelled. It
is a general model which encapsulates several important scheduling, routing and
resource allocation problems in literature. Many of the state-of-the-art heuristics for
solve scheduling problems and indeed other problems require specialised heuristics
tailored for the problem they are to solve. While these provide good solutions a lot of
expert time is needed to study the problem, and implement solutions.
This research investigates methods to enhance existing search based methods.
We study hyperheuristic techniques as a general search based heuristic. Hyperheuristics
raise the generality of the solution method by using a set of tools (low level heuristics)
to work on the solution. These tools are problem specific and usually make small
changes to the problem. It is the task of the hyperheuristic to determine which tool to
use and when. Low level heuristics using exact/heuristic hybrid method are used in this
thesis along with a new Tabu based hyperheuristic which decreases the amount of CPU
time required to produce good quality solutions. We also develop and investigate the
Variable Fitness Function approach, which provides a new way of enhancing most
search-based heuristics in terms of solution quality. If a fitness function is pushing hard
in a certain direction, a heuristic may ultimately fail because it cannot escape local
minima. The Variable Fitness Function allows the fitness function to change over the
search and use objective measures not used in the fitness calculation. The Variable
Fitness Function and its ability to generalise are extensively tested in this thesis.
The two aims of the thesis are achieved and the methods are analysed in depth.
General conclusions and areas of future work are also identified.
18
WEGNER, SVEN-AKE. « Projective limits of weighted (LB) - spaces of holomorphic functions ». Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8480.
Texte intégralRésumé :
Los límites proyectivos de límites inductivos de espacios de Banach, también llamados espacios (PLB), surgen de forma natural en el análisis matemático.
En esta tesis estudiamos espacios (PLB), cuyos bloques de construcción son espacios de Banach de funciones holomorfas definidas por normas supremo ponderadas. El estudio de estos espacios extiende la investigación
de Agethen, Bierstedt, Bonet quienes han considerado recientemente espacios (PLB) ponderados de funciones continuas. Desde otra perspectiva, extiende la investigación de límites inductivos ponderados de espacios de Banach de funciones holomorfas, los cuales han sido analizados intensamente por varios autores los últimos años.
Nuestro propósito es estudiar las propiedades localmente convexas de los espacios descritos arriba. En particular, investigamos cuando son ultrabornológicos o tonelados. Además, investigamos bajo qué circunstancias se pueden intercambiar el límite proyectivo y el inductivo y por lo tanto el espacio
(PLB) coincide con el límite inductivo de espacios de Fréchet definidos por la misma sucesión; espacios de este último tipo has sido investigados por Bierstedt, Bonet. Probamos condiciones necesarias para las propiedades de los espacios antes mencionadas bajo hipótesis muy poco restrictivas. En cuanto a
condiciones suficientes usamos métodos homológicos, cuya exploración fue iniciada por Palamodov al
final de los sesenta y continuada por Vogt, Wengenroth y otros a lo largo de los últimos 40 años. Presentamos también un criterio para decidir si los espacios son tonelados adaptado a estas situaciones. No obstante, parece ser inevitable descomponer funciones holomorfas para probar cualquier resultado relativo a a las condiciones suficientes. Por lo tanto introducimos varios contextos en los cuales lo último es posible,
dentro de estos contextos conseguimos la descomposición de diferentes formas;
es decir, por descomposición de polinomios (en el disco y en el espacio), un método conectado con la teoría de proyecciones de Bergman, dos tipos de representaciones del espacio de sucesiones y el método de Hörmander. Bajo algunas hipótesis adicionales (satisfechas, como mostramos, por muchos ejemplos) damos en casi todos los contextos mencionados anteriormente unas caracterizaciones completas de cuándo el espacio es ultrabornológico, cuándo es tonelado y cuándo los límites inductivo y projectivo son intercambiables.
Para finalizar nuestra investigación de espacios (PLB) ponderados, presentamos dos resultados que muestran que espacios de este tipo se pueden escribir en algunos casos como el producto tensorial de un espacio de Fréchet y un espacio (DF). El segundo resultado acerca de representaciones de productos tensoriales muestra que algunos espacios de ultradistribuciones (introducidos recientemente por Schmets y Valdivia) resultan ser espacios-(PLB) ponderados de funciones holomorfas.Wegner, S. (2010). Projective limits of weighted (LB) - spaces of holomorphic functions [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8480
Palancia
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Pelagia, Ioanna. « Variable selection of fixed effects and frailties for Cox Proportional Hazard frailty models and competing risks frailty models ». Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/variable-selection-of-fixed-effects-and-frailties-for-cox-proportional-hazard-frailty-models-and-competing-risks-frailty-models(c75c6314-f43e-4d69-a2de-942bece6a404).html.
Texte intégralRésumé :
This thesis focuses on two fundamental topics, specifically in medical statistics: the modelling of correlated survival datasets and the variable selection of the significant covariates and random effects. In particular, two types of survival data are considered: the classical survival datasets, where subjects are likely to experience only one type of event and the competing risks datasets, where subjects are likely to experience one of several types of event. In Chapter 2, among other topics, we highlight the importance of adding frailty terms on the proposed models in order to account for the association between the survival time and characteristics of subjects/groups. The main novelty of this thesis is to simultaneously select fixed effects and frailty terms through the proposed statistical models for each survival dataset. Chapter 3 covers the analysis of the classical survival dataset through the proposed Cox Proportional Hazard (PH) model. Utilizing a Cox PH frailty model, may increase the dimension of variable components and estimation of the unknown coefficients becomes very challenging. The method proposed for the analysis of classical survival datasets involves simultaneous variable selection on both fixed effects and frailty terms through penalty functions. The benefit of penalty functions is that they identify the non-significant parameters and set them to have a zero effect in the model. Hence, the idea is to 'doubly-penalize' the partial likelihood of the Cox PH frailty model; one penalty for each term. Estimation and selection implemented through Newton-Raphson algorithms, whereas closed iterative forms for the estimation and selection of fixed effects and prediction of frailty terms were obtained. For the selection of frailty terms, penalties imposed on their variances since frailties are random effects. Based on the same idea, we further extend the simultaneous variable selection in the competing risks datasets in Chapter 4, using extended cause-specific frailty models. Two different scenarios are considered for frailty terms; in the first case we consider that frailty terms vary among different types of events (similar to the fixed effects) whereas in the second case we consider shared frailties over all the types of events. Moreover, our 'individual penalization' approach allows for one covariate to be significant for some types of events, in contrast to the frequently used 'group-penalization' where a covariate is entirely removed when it is not significant over all the events. For both proposed methods, simulation studies were conduced and showed that the proposed procedure followed for each analysis works well in simultaneously selecting and estimating significant fixed effects and frailty terms. The proposed methods are also applied to real datasets analysis; Kidney catheter infections, Diabetes Type 2 and Breast Cancer datasets. Association of the survival times and unmeasured characteristics of the subjects was studied as well as a variable selection for fixed effects and frailties implemented successfully.
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Luizelli, Marcelo Caggiani. « Scalable cost-efficient placement and chaining of virtual network functions ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/169337.
Texte intégralRésumé :
A Virtualização de Funções de Rede (NFV – Network Function Virtualization) é um novo conceito arquitetural que está remodelando a operação de funções de rede (e.g., firewall, gateways e proxies). O conceito principal de NFV consiste em desacoplar a lógica de funções de rede dos dispositivos de hardware especializados e, desta forma, permite a execução de imagens de software sobre hardware de prateleira (COTS – Commercial Off-The-Shelf). NFV tem o potencial para tornar a operação das funções de rede mais flexíveis e econômicas, primordiais em ambientes onde o número de funções implantadas pode chegar facilmente à ordem de centenas. Apesar da intensa atividade de pesquisa na área, o problema de posicionar e encadear funções de rede virtuais (VNF – Virtual Network Functions) de maneira escalável e com baixo custo ainda apresenta uma série de limitações. Mais especificamente, as estratégias existentes na literatura negligenciam o aspecto de encadeamento de VNFs (i.e., objetivam sobretudo o posicionamento), não escalam para o tamanho das infraestruturas NFV (i.e., milhares de nós com capacidade de computação) e, por último, baseiam a qualidade das soluções obtidas em custos operacionais não representativos. Nesta tese, aborda-se o posicionamento e o encadeamento de funções de rede virtualizadas (VNFPC – Virtual Network Function Placement and Chaining) como um problema de otimização no contexto intra- e inter-datacenter. Primeiro, formaliza-se o problema VNFPC e propõe-se um modelo de Programação Linear Inteira (ILP) para resolvêlo. O objetivo consiste em minimizar a alocação de recursos, ao mesmo tempo que atende aos requisitos e restrições de fluxo de rede. Segundo, aborda-se a escalabilidade do problema VNFPC para resolver grandes instâncias do problema (i.e., milhares de nós NFV). Propõe-se um um algoritmo heurístico baseado em fix-and-optimize que incorpora a meta-heurística Variable Neighborhood Search (VNS) para explorar eficientemente o espaço de solução do problema VNFPC. Terceiro, avalia-se as limitações de desempenho e os custos operacionais de estratégias típicas de aprovisionamento ambientes reais de NFV. Com base nos resultados empíricos coletados, propõe-se um modelo analítico que estima com alta precisão os custos operacionais para requisitos de VNFs arbitrários. Quarto, desenvolve-se um mecanismo para a implantação de encadeamentos de VNFs no contexto intra-datacenter. O algoritmo proposto (OCM – Operational Cost Minimization) baseia-se em uma extensão da redução bem conhecida do problema de emparelhamento ponderado (i.e., weighted perfect matching problem) para o problema de fluxo de custo mínimo (i.e., min-cost flow problem) e considera o desempenho das VNFs (e.g., requisitos de CPU), bem como os custos operacionais estimados. Os resultados alcaçados mostram que o modelo ILP proposto para o problema VNFPC reduz em até 25% nos atrasos fim-a-fim (em comparação com os encadeamentos observados nas infra-estruturas tradicionais) com um excesso de provisionamento de recursos aceitável – limitado a 4%. Além disso, os resultados evidenciam que a heurística proposta (baseada em fix-and-optimize) é capaz de encontrar soluções factíveis de alta qualidade de forma eficiente, mesmo em cenários com milhares de VNFs. Além disso, provê-se um melhor entendimento sobre as métricas de desempenho de rede (e.g., vazão, consumo de CPU e capacidade de processamento de pacotes) para as estratégias típicas de implantação de VNFs adotadas infraestruturas NFV. Por último, o algoritmo proposto no contexto intra-datacenter (i.e. OCM) reduz significativamente os custos operacionais quando comparado aos mecanismos de posicionamento típicos utiNetwork Function Virtualization (NFV) is a novel concept that is reshaping the middlebox arena, shifting network functions (e.g. firewall, gateways, proxies) from specialized hardware appliances to software images running on commodity hardware. This concept has potential to make network function provision and operation more flexible and cost-effective, paramount in a world where deployed middleboxes may easily reach the order of hundreds. Despite recent research activity in the field, little has been done towards scalable and cost-efficient placement & chaining of virtual network functions (VNFs) – a key feature for the effective success of NFV. More specifically, existing strategies have neglected the chaining aspect of NFV (focusing on efficient placement only), failed to scale to hundreds of network functions and relied on unrealistic operational costs. In this thesis, we approach VNF placement and chaining as an optimization problem in the context of Inter- and Intra-datacenter. First, we formalize the Virtual Network Function Placement and Chaining (VNFPC) problem and propose an Integer Linear Programming (ILP) model to solve it. The goal is to minimize required resource allocation, while meeting network flow requirements and constraints. Then, we address scalability of VNFPC problem to solve large instances (i.e., thousands of NFV nodes) by proposing a fixand- optimize-based heuristic algorithm for tackling it. Our algorithm incorporates a Variable Neighborhood Search (VNS) meta-heuristic, for efficiently exploring the placement and chaining solution space. Further, we assess the performance limitations of typical NFV-based deployments and the incurred operational costs of commodity servers and propose an analytical model that accurately predict the operational costs for arbitrary service chain requirements. Then, we develop a general service chain intra-datacenter deployment mechanism (named OCM – Operational Cost Minimization) that considers both the actual performance of the service chains (e.g., CPU requirements) as well as the operational incurred cost. Our novel algorithm is based on an extension of the well-known reduction from weighted matching to min-cost flow problem. Finally, we tackle the problem of monitoring service chains in NFV-based environments. For that, we introduce the DNM (Distributed Network Monitoring) problem and propose an optimization model to solve it. DNM allows service chain segments to be independently monitored, which allows specialized network monitoring requirements to be met in a efficient and coordinated way. Results show that the proposed ILP model for the VNFPC problem leads to a reduction of up to 25% in end-to-end delays (in comparison to chainings observed in traditional infrastructures) and an acceptable resource over-provisioning limited to 4%. Also, we provide strong evidences that our fix-and-optimize based heuristic is able to find feasible, high-quality solutions efficiently, even in scenarios scaling to thousands of VNFs. Further, we provide indepth insights on network performance metrics (such as throughput, CPU utilization and packet processing) and its current limitations while considering typical deployment strategies. Our OCM algorithm reduces significantly operational costs when compared to the de-facto standard placement mechanisms used in Cloud systems. Last, our DNM model allows finer grained network monitoring with limited overheads. By coordinating the placement of monitoring sinks and the forwarding of network monitoring traffic, DNM can reduce the number of monitoring sinks and the network resource consumption (54% lower than a traditional method).
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Junior, Jony Arrais Pinto. « Seleção de covariáveis para modelos de sobrevivência via verossimilhança penalizada ». Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-28072009-214959/.
Texte intégralRésumé :
A seleção de variáveis é uma importante fase para a construção de um modelo parcimonioso. Entretanto, as técnicas mais populares de seleção de variáveis, como, por exemplo, a seleção do melhor subconjunto de variáveis e o método stepwise, ignoram erros estocásticos inerentes à fase de seleção das variáveis. Neste trabalho, foram estudados procedimentos alternativos aos métodos mais populares para o modelo de riscos proporcionais de Cox e o modelo de Cox com fragilidade gama. Os métodos alternativos são baseados em verossimilhançaa penalizada e diferem dos métodos usuais de seleção de variáveis, pois têm como objetivo excluir do modelo variáveis não significantes estimando seus coeficientes como zero. O estimador resultante possui propriedades desejáveis com escolhas apropriadas de funções de penalidade e do parâmetro de suavização. A avaliação desses métodos foi realizada por meio de simulação e uma aplicação a um conjunto de dados reais foi considerada.Variable selection is an important step when setting a parsimonious model. However, the most popular variable selection techniques, such as the best subset variable selection and the stepwise method, do not take into account inherent stochastic errors in the variable selection step. This work presents a study of alternative procedures to more popular methods for the Cox proportional hazards model and the frailty model. The alternative methods are based on penalized likelihood and differ from the usual variable selection methods, since their objective is to exclude from the model non significant variables, estimating their coefficient as zero. The resulting estimator has nice properties with appropriate choices of penalty functions and the tuning parameter. The assessment of these methods was studied through simulations, and an application to a real data set was considered.
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Cervo, Victor Leonardo. « Seleção de variáveis para clusterização através de índices de importância das variáveis e Análise de Componentes Principais ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/75915.
Texte intégralRésumé :
A presente dissertação propõe novas abordagens para seleção de variáveis com vistas à formação de grupos representativos de observações. Para tanto, sugere um novo índice de importância das variáveis apoiado nos parâmetros oriundos da Análise de Componentes Principais (APC), o qual é integrado a uma sistemática do tipo forward para seleção de variáveis. A qualidade dos agrupamentos formados é medida através do Silhouette Index. Um estudo de simulação é projetado para avaliar a robustez e o desempenho da sistemática proposta em dados com diferentes níveis de correlação, ruído e número de observações a serem clusterizadas. Na sequência, é apresentada uma versão modificada da sistemática original, a qual utiliza funções kernel para remapeamento dos dados com vistas ao incremento da qualidade de clusterização e redução das variáveis retidas para formação dos agrupamentos. A versão modificada é aplicada em 3 bancos de dados da indústria química, aumentando a qualidade da clusterização medida pelo SI médio em 150% e utilizando em torno de 6% das variáveis originais.This thesis proposes new approaches for variable selection aimed at forming representative groups of observations. For that matter, we suggest a new variable importance index based on parameters derived from the Principal Component Analysis (PCA), which is integrated to a forward procedure for variable selection. The quality of clustering procedure is assessed by the Silhouette Index. A simulation study is designed to evaluate the robustness of the proposed method on different levels of variable correlation, noise and number of observations to be clustered. Next, we modify the original method by remapping observations through kernel functions tailored to improving the clustering quality and reducing the retained variables. The modified version is applied to 3 databases related to chemical processes, increasing the quality of clustering measured by SI on average 150%, while using around 6% of the original variables.
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Lee, Jin Woo. « Multi-level Decoupled Optimization of Wind Turbine Structures Using Coefficients of Approximating Functions as Design Variables ». University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1501003238831086.
Texte intégral
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Loganathan, Ramanan Mayoorathen. « Solutions for the flows induced by lazy, forced and pure turbulent plumes ». Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273741.
Texte intégralRésumé :
In this thesis an analytical modelling approach is employed to predict and gain insight into the flows induced by turbulent plumes and jets above slender horizontal slots, in otherwise quiescent uniform environments. To supplement the solutions, the effect on the environment of a plume driven by an off-source supply of buoyancy was also considered. The solutions derived provide an advancement on existing idealised models for the jet and plume induced flows, and moreover, complement a number of key advances that have been made in our understanding of plume flows in recent years. The theory of functions of a complex variable, which has not previously been applied in such an application, has been utilised as a fundamental tool throughout the work. This has enabled the entrainment behaviour and geometry of the plumes to be accounted for when developing the induced flow solutions. A novel conformal mapping has been devised specifically to account for the curved perimeter of the contracting lazy plume. This modelling approach is robust in that future developments to aspects of the modelling, for instance, the formulation of a new entrainment closure, can be straightforwardly accounted for using the method. The induced flow solutions exhibit a range of flow patterns which are dependent on the source Richardson number of the plume flow. A pure plume induces a uniform horizontal flow. Forced and lazy plumes correspond to a relative deficit and excess in source buoyancy flux compared to the pure plume, respectively. Generally, forced plumes induce downwardly inclined flows, in contrast to lazy plumes, which induce upwardly inclined flows. Consistent with these solutions, the notionally lazy plume driven by a vertical uniform off-source supply of buoyancy induces an upwardly inclined flow. In addition to an improved understanding of induced flows, our solutions have provided us with insight into the plume flow. Notably, the solution corresponding to the forced plume has led us to fundamentally question existing models describing the plume and, in particular, closures that have been employed to model entrainment. We find that the existing well accepted closures exhibit some form of non-physical flow behaviour.
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Raoult, Cécile. « Modélisation numérique non-linéaire et dispersive des vagues en zone côtière ». Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1150/document.
Texte intégralRésumé :
Au cours de cette thèse, un modèle potentiel résolvant les équations d’Euler-Zakharov a été développé dans le but de simuler la propagation de vagues et d’états de mer irréguliers et multi-directionnels, du large jusqu’à la côte, sur des bathymétries variables. L’objectif est de représenter les effets non-linéaires et dispersifs le plus précisément possible pour des domainescôtiers bidimensionnels (dans le plan horizontal) de l’ordre de quelques kilomètres.La version 1DH initiale du modèle, résolvant le problème aux limites de Laplace à l’aide de schémas aux différences finies d’ordre élevé dans la direction horizontale combinés à une approche spectrale sur la verticale, a été améliorée et validée. L’implémentation de conditions aux limites de type Dirichlet et Neumann pour générer des vagues dans le domaine a été étudiée en détail. Dans la pratique, une zone de relaxation a été utilisée en complément deces conditions pour améliorer la stabilité du modèle.L’expression analytique de la relation de dispersion a été établie dans le cas d’un fond plat. Son analyse a montré que la représentation des effets dispersifs s’améliorait significativement avec l’augmentation de la résolution sur la direction verticale (i.e. avec le degré maximal de la basede polynômes de Tchebyshev utilisée pour projeter le potentiel des vitesses sur la verticale).Une étude de convergence menée pour des ondes solitaires modérément à fortement non-linéaires a confirmé la convergence exponentielle avec la résolution verticale grâce à l’approche spectrale, ainsi que les convergences algébriques en temps et en espace sur l’horizontale avec des ordres d’environ 4 (ou plus) en accord avec les schémas numériques utilisés.La comparaison des résultats du modèle à plusieurs jeux de données expérimentales a démontré les capacités du modèle à représenter les effets non-linéaires induits par les variations de bathymétrie, notamment les transferts d’énergie entre les composantes harmoniques, ainsi que la représentation précise des propriétés dispersives. Une formulation visco-potentielle a également été implémentée afin de prendre en compte les effets visqueux induits par la dissipation interne et le frottement sur le fond. Cette formulation a été validée dans le cas d’une faible viscosité avec un fond plat ou présentant une faible pente.Dans le but de représenter des champs de vagues 2DH, le modèle a été étendu en utilisant une discrétisation non-structurée (par nuage de points) du plan horizontal. Les dérivées horizontales ont été estimées à l’aide de la méthode RBF-FD (Radial Basis Function-Finite Difference), en conservant l’approche spectrale sur la verticale. Une étude numérique de sensibilité a été menée afin d’évaluer la robustesse de la méthode RBF-FD, en comparant différents types de RBFs, avec ou sans paramètre de forme et l’ajout éventuel d’un polynôme. La version 2DH du modèle a été utilisée pour simuler deux expériences en bassin, validant ainsi l’approche choisie et démontrant son applicabilité pour simuler la propagation 3D des vagues faisant intervenir des effets non-linéaires. Dans le but de réduire le temps de calcul et de pouvoir appliquer le code à des simulations sur de grands domaines, le code a été modifié pour utiliser le solveur linéaire direct en mode parallèleIn this work, a potential flow model based on the Euler-Zakharov equations was developed with the objective of simulating the propagation of irregular and multidirectional sea states from deep water conditions to the coast over variable bathymetry. A highly accurate representation of nonlinear and dispersive effects for bidimensional (2DH) nearshore and coastal domains on the order of kilometers is targeted.The preexisting 1DH version of the model, resolving the Laplace Boundary Value problem using a combination of high-order finite difference schemes in the horizontal direction and a spectral approach in the vertical direction, was improved and validated. The generation of incident waves through the implementation of specific Dirichlet and Neumann boundary conditions was studied in detail. In practice, these conditions were used in combination witha relaxation zone to improve the stability of the model.The linear dispersion relation of the model was derived analytically for the flat bottom case. Its analysis showed that the accuracy of the representation of dispersive effects improves significantly by increasing the vertical resolution (i.e. the maximum degree of the Chebyshev polynomial basis used to project the potential in the vertical). A convergence study conducted for moderate to highly nonlinear solitary waves confirmed the exponential convergence in the vertical dimension owing to the spectral approach, and the algebraic convergence in time and in space (horizontal dimension) with orders of about 4 (or higher) in agreement with the numerical schemes used.The capability of the model to represent nonlinear effects induced by variable bathymetry, such as the transfer of energy between harmonic components, as well as the accurate representation of dispersive properties, were demonstrated with comparisons to several experimental data sets. A visco-potential flow formulation was also implemented to take into account viscous effects induced by bulk viscosity and bottom friction. This formulation was validated inthe limit of small viscosity for mild slope bathymetries.To represent 2DH wave fields in complex nearshore domains, the model was extended using an unstructured discretization (scattered nodes) in the horizontal plane. The horizontal derivatives were estimated using the RBF-FD (Radial Basis Function - Finite Difference) method, while the spectral approach in the vertical remained unchanged. A series of sensitivity tests were conducted to evaluate numerically the robustness of the RBF-FD method, including a comparison of a variety of RBFs with or without shape factors and augmented polynomials. The 2DH version of the model was used to simulate two wave basin experiments, validating the approach and demonstrating the applicability of this method for 3D wave propagation, including nonlinear effects. As an initial attempt to improve the computational efficiency ofthe model for running simulations of large spatial domains, the code was adapted to use a parallelized direct linear solver
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Santos, Rafael Ribeiro dos. « Um framework para agrupar funções com base no comportamento da comunicação de dados em plataformas multiprocessadas ». Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-24102018-100329/.
Texte intégralRésumé :
O aumento da demanda por sistemas computacionais mais eficientes para obter alto desempenho impôs novos desafios à comunidade de pesquisa, que precisou buscar por novas plataformas heterogêneas para grandes aplicações. Para utilizar todo o potencial dessas plataformas, podese agrupar a aplicação em grupos menores de modo que cada grupo seja executado em uma unidade de processamento específica, para reduzir o gargalo de comunicação, de acordo com o comportamento de comunicação durante a execução da aplicação. Com o propósito de oferecer um agrupamento mais eficiente, este projeto propõe a análise de agrupamento de uma aplicação levando em consideração não só o volume total de dados, mas também a distribuição desse volume durante o tempo de execução associado à restrição da banda e da taxa de transmissão. Embora alguns trabalhos considerem o volume total de dados para o agrupamento, não é evidenciado como esse volume é distribuído e como a restrição de banda afeta o agrupamento. Assim, neste projeto foi implementado um framework para sugerir um agrupamento considerando a distribuição do volume de comunicação e restrições de banda. Além disso, foi desenvolvido um módulo de extensão para a ferramenta externa MCProf (Memory and Communication Profiler) com o objetivo de obter a distribuição do volume de comunicação. A validação do framework foi realizada por meios de testes de agrupamentos de aplicações nos quais foram comparados o tempo de comunicação do agrupamento gerado pela execução do framework em relação aos resultado dos agrupamentos considerando os trabalhos da literatura. O uso desta abordagem apresentou um aumento no desempenho que variou de 1,117X a 2,621X para as aplicações usadas nos experimentos.The increased demand for more efficient computing systems to achieve high performance proposed new challenges to the research community, which needed to search for new heterogeneous platforms for large applications. To utilize the full potential of these platforms, the application can be grouped into small groups that runs on a specific processing unit to reduce the communication bottleneck according to the communication behavior during application execution . With the purpose of offering a more efficient clustering, this project proposes the analysis of clustering of an application taking into account not only the total volume of data, but also the distribution of that volume during the execution time associated to the band and restriction of rate transmission. Although some studies consider the total volume of data for the cluster, it is not clear how this volume is distributed and how the band constraint affects clustering. Thus, in this project was implemented a framework to suggest a cluster considering the distribution of the volume of communication and band restrictions. In addition, an extension module was developed for the external tool MCProf (Memory and Communication Profiler) in order to obtain the distribution of the communication. The validation of the framework was performed by clsutering tests which used applications in which the communication time of the cluster generated by the execution of framework was compared to the results of the clusters considering the literature. The use of this approach showed an increase in performance ranging from 1.117X to 2.621X for the applications used in the experiments.
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Monzon, Larissa Weyh. « Números complexos e funções de variável complexa no ensino médio : uma proposta didática com uso de objeto de aprendizagem ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/56236.
Texte intégralRésumé :
A presente dissertação tem como propósito apresentar uma proposta didática para o ensino de números complexos e funções de variável complexa, fazendo uso de um objeto de aprendizagem. Para o embasamento teórico, quanto ao processo de construção de conhecimento, referenciamos Vygotsky e Piaget. Também foi feita uma análise das tecnologias como ferramenta para o ensino e, em especial quanto às possibilidades que dizem respeito aos registros dinâmicos de representação semiótica. A metodologia para conceber, realizar e analisar a proposta didática é a Engenharia Didática. Essa metodologia permitiu uma detalhada validação da sequência didática que integra o uso do objeto de aprendizagem "Números Complexos" com animações interativas, vídeos, explicações e exercícios. A sequência foi implementada em um terceiro ano do Ensino Médio.This work presents a suggestion of a didactical sequence for teaching complex numbers and functions in high school. The sequence supposes the use of the learning object "Complex Numbers" with interactive animations, videos and exercises. As a theoretical frame to support our understanding of the knowledge construction process it was taken into account the Vygotsky´s theory and Piaget´s theory. A discussion about the potential of technologies as a teaching tool is also presented, specially about the possibilities related to dynamical semiotic representation in mathematics. The research methodology used was Didactical Engineering. With this methodology was possible to implemented and validate the didactical sequence.
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Sevinik, Adiguzel Rezan. « On The Q-analysis Of Q-hypergeometric Difference Equation ». Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612758/index.pdf.
Texte intégralRésumé :
In this thesis, a fairly detailed survey on the q-classical orthogonal polynomials of the Hahn
class is presented. Such polynomials appear to be the bounded solutions of the so called qhypergeometric
difference equation having polynomial coefficients of degree at most two. The
central idea behind our study is to discuss in a unified sense the orthogonality of all possible
polynomial solutions of the q-hypergeometric difference equation by means of a qualitative
analysis of the relevant q-Pearson equation. To be more specific, a geometrical approach has
been used by taking into account every posssible rational form of the polynomial coefficients,
together with various relative positions of their zeros, in the q-Pearson equation to describe a
desired q-weight function on a suitable orthogonality interval. Therefore, our method differs
from the standard ones which are based on the Favard theorem and the three-term recurrence
relation.
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Cosler, Douglas Jay. « Numerical investigation of field-scale convective mixing processes in heterogeneous, variable-density flow systems using high-resolution adaptive mesh refinement methods ». Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1148412827.
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Larsson, David. « Generalized Riemann Integration : Killing Two Birds with One Stone ? » Thesis, Linköpings universitet, Matematik och tillämpad matematik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-96661.
Texte intégralRésumé :
Since the time of Cauchy, integration theory has in the main been an attempt to regain the Eden of Newton. In that idyllic time [. . . ] derivatives and integrals were [. . . ] different aspects of the same thing. -Peter Bullen, as quoted in [24] The theory of integration has gone through many changes in the past centuries and, in particular, there has been a tension between the Riemann and the Lebesgue approach to integration. Riemann's definition is often the first integral to be introduced in undergraduate studies, while Lebesgue's integral is more powerful but also more complicated and its methods are often postponed until graduate or advanced undergraduate studies. The integral presented in this paper is due to the work of Ralph Henstock and Jaroslav Kurzweil. By a simple exchange of the criterion for integrability in Riemann's definition a powerful integral with many properties of the Lebesgue integral was found. Further, the generalized Riemann integral expands the class of integrable functions with respect to Lebesgue integrals, while there is a characterization of the Lebesgue integral in terms of absolute integrability. As this definition expands the class of functions beyond absolutely integrable functions, some theorems become more cumbersome to prove in contrast to elegant results in Lebesgue's theory and some important properties in composition are lost. Further, it is not as easily abstracted as the Lebesgue integral. Therefore, the generalized Riemann integral should be thought of as a complement to Lebesgue's definition and not as a replacement.Ända sedan Cauchys tid har integrationsteori i huvudsak varit ett försök att åter finna Newtons Eden. Under den idylliska perioden [. . . ] var derivator och integraler [. . . ] olika sidor av samma mynt.-Peter Bullen, citerad i [24] Under de senaste århundradena har integrationsteori genomgått många förändringar och framförallt har det funnits en spänning mellan Riemanns och Lebesgues respektive angreppssätt till integration. Riemanns definition är ofta den första integral som möter en student pa grundutbildningen, medan Lebesgues integral är kraftfullare. Eftersom Lebesgues definition är mer komplicerad introduceras den först i forskarutbildnings- eller avancerade grundutbildningskurser. Integralen som framställs i det här examensarbetet utvecklades av Ralph Henstock och Jaroslav Kurzweil. Genom att på ett enkelt sätt ändra kriteriet for integrerbarhet i Riemanns definition finner vi en kraftfull integral med många av Lebesgueintegralens egenskaper. Vidare utvidgar den generaliserade Riemannintegralen klassen av integrerbara funktioner i jämförelse med Lebesgueintegralen, medan vi samtidigt erhåller en karaktärisering av Lebesgueintegralen i termer av absolutintegrerbarhet. Eftersom klassen av generaliserat Riemannintegrerbara funktioner är större än de absolutintegrerbara funktionerna blir vissa satser mer omständiga att bevisa i jämforelse med eleganta resultat i Lebesgues teori. Därtill förloras vissa viktiga egenskaper vid sammansättning av funktioner och även möjligheten till abstraktion försvåras. Integralen ska alltså ses som ett komplement till Lebesgues definition och inte en ersättning.
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Amaral, Amaury de Souza. « Análise de funções booleanas e engenharia reversa em jogos ». reponame:Repositório Institucional da UFABC, 2013.
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Oliveira, Gabriela Martins Gonçalves de. « Ajuste de parâmetros em algoritmos de aprendizado de máquina utilizando transferência de aprendizado ». reponame:Repositório Institucional da UFABC, 2014.
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Farquhar, Megan Elizabeth. « Cardiac modelling with fractional calculus : An efficient computational framework for modelling the propagation of electrical impulses in the heart ». Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/120682/1/__qut.edu.au_Documents_StaffHome_StaffGroupH%24_halla_Desktop_Megan_Farquhar_Thesis.pdf.
Texte intégralRésumé :
Heart failure is one of the most common causes of death in the western world. Many heart problems are linked to disturbances in cardiac electrical activity. Further understanding of how electrical impulses propagate through the heart may lead to new diagnosis and treatment options.
Using our novel numerical scheme, we are able to conduct preliminary investigations into the effect of fixed and variable order fractional Laplacian operators for modelling propagation of electrical impulses through the heart. We implement our numerical framework to solve the coupled monodomain, Beeler-Reuter model. Preliminary results confirm the effectiveness of our numerical scheme, and pave the way to exciting areas of future research.
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Crambes, Christophe. « Modèles de régression linéaire pour variables explicatives fonctionnelles ». Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00134003.
Texte intégralRésumé :
L'analyse des données fonctionnelles constitue une branche de la statistique dont le développement s'est fortement intensifié ces dernières années. Dans cette thèse, on s'intéresse à des problèmes de régression fonctionnelle pour lesquels il s'agit d'expliquer les variations d'une variable d'intérêt réelle à partir d'une variable explicative fonctionnelle, c'est-à-dire à valeur dans un espace de dimension éventuellement infinie. On considère plus précisément des modèles de régression linéaire. Deux types d'estimation sont proposés: l'estimation de quantiles conditionnels et l'estimation de la moyenne conditionnelle (cette dernière étant considérée dans le cas où la variable explicative est non bruitée, puis lorsque celle-ci est soumise à des erreurs de mesure). Dans chaque cas, des estimateurs basés sur les fonctions splines sont proposés, solutions de problèmes de minimisation pénalisés, la pénalisation intervenant pour contourner le problème lié au fait que la variable explicative est à valeurs dans un espace de dimension infinie. Finalement, on s'intéresse aux aspects pratique de cette étude, au moyen de simulations, puis sur un jeu de données réelles concernant la prévision de pics de pollution à l'ozone à Toulouse.
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Signorelli, Shirley Ferreira. « Um ambiente virtual para o ensino semipresencial de funções de uma variável real : design e análise ». Pontifícia Universidade Católica de São Paulo, 2007. https://tede2.pucsp.br/handle/handle/11284.
Texte intégralRésumé :
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The purpose of this investigation was the elaboration and implementation of a virtual environment for a part time distance course for students of the Computer Science and Systems of Information. The students failed in a former discipline that approaches topics of elementary Mathematics. It happened in a particular university in the city of São Paulo. Our focus was on analyzing this environment, the tools and interactions that happened on distance mode, about the content of real function of one variable. The methodology used, design-based research, favored proposing and analyzing the activities about this topic, as well as their reorganization and, the re design of the environment. The Blackboard platform and the used tools were analyzed based on Chaves (2000) criteria, and it seemed efficient as a virtual environment for the learning in our course. However, we leaved some critical and suggestions for future works, mainly about the role of the tools for communication within part time distance courses. The analysis of the students and teacher speeches' was based on the Model of Argumentative Strategy (CASTRO et al, 2004) and allowed to raise some aspects on the understanding of Real Functions of one variable, as they were privileged in the different interactive spaces such as forum, chat, email and daily log. Aspects like the meaning production in Mathematics can be produced due to the authority of a teacher or of another student who is considered good by the classroom peers, or based on everyday language usage or on cultural characteristics. Moreover, we found that besides the students lack of prerequisite elementary mathematics, there is a lack of a culture for on-line courses
Nesta pesquisa objetivamos a elaboração e implementação de um ambiente virtual para um curso semipresencial, para estudantes dos cursos de Bacharelado em Ciência da Computação e Sistemas de Informação de uma instituição particular na cidade de São Paulo, dependentes na disciplina que aborda tópicos de pré-calculo. Nosso foco recaiu na análise do ambiente, da viabilidade das ferramentas e das interações que ocorreram a distância, no que tange o conteúdo de Funções de uma Variável Real. A metodologia utilizada, design research, permitiu propor e analisar as atividades sobre este tópico, incluindo a reestruturação e complementação deste ambiente. A plataforma Blackboard e as ferramentas foram analisadas segundo critérios definidos por Chaves (2000) e se mostraram eficazes como ambiente virtual de aprendizagem atendendo, para nosso curso, os critérios necessários. Entretanto, deixamos algumas críticas e sugestões para trabalhos futuros, principalmente quanto o papel do uso de ferramentas de comunicação em cursos semipresenciais. A análise dos discursos dos alunos e docente baseados no Modelo de Estratégia Argumentativa (CASTRO et al, 2004) permitiu levantar alguns aspectos sobre a compreensão de Funções de uma Variável Real que foram privilegiados nos diferentes espaços interativos como fórum, chat, e-mail e diário de rotina, tais como o fato de que a produção de significados em Matemática pode estar apoiada na autoridade do professor ou alunos bem vistos pela classe, na linguagem cotidiana e no aspecto cultural. Observamos ainda que além da falta de pré-requisitos de matemática básica, ainda há falta de cultura de trabalhos on-line
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Hunt, Julian David. « Integration of rationale management with multi-criteria decision analysis, probabilistic forecasting and semantics : application to the UK energy sector ». Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:2cc24d23-3e93-42e0-bb7a-6e39a65d7425.
Texte intégralRésumé :
This thesis presents a new integrated tool and decision support framework to approach complex problems resulting from the interaction of many multi-criteria issues. The framework is embedded in an integrated tool called OUTDO (Oxford University Tool for Decision Organisation). OUTDO integrates Multi-Criteria Decision Analysis (MCDA), decision rationale management with a modified Issue-Based Information Systems (IBIS) representation, and probabilistic forecasting to effectively capture the essential reasons why decisions are made and to dynamically re-use the rationale. In doing so, it allows exploration of how changes in external parameters affect complicated and uncertain decision making processes in the present and in the future. Once the decision maker constructs his or her own decision process, OUTDO checks if the decision process is consistent and coherent and looks for possible ways to improve it using three new semantic-based decision support approaches. For this reason, two ontologies (the Decision Ontology and the Energy Ontology) were integrated into OUTDO to provide it with these semantic capabilities. The Decision Ontology keeps a record of the decision rationale extracted from OUTDO and the Energy Ontology describes the energy generation domain, focusing on the water requirement in thermoelectric power plants. A case study, with the objective of recommending electricity generation and steam condensation technologies for ten different regions in the UK, is used to verify OUTDO’s features and reach conclusions about the overall work.
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Bensedik, Ahmed. « Sur quelques problèmes elliptiques de type Kirchhoff et dynamique des fluides ». Phd thesis, Université Jean Monnet - Saint-Etienne, 2012. http://tel.archives-ouvertes.fr/tel-00971279.
Texte intégralRésumé :
Cette thèse est composée de deux parties indépendantes. La première est consacrée à l'étude de quelques problèmes elliptiques de type de Kirchhoff de la forme suivante : -M(ʃΩNul² dx) Δu = f(x, u) xЄΩ ; u(x) = o xЄƋΩ où Ω cRN, N ≥ 2, f une fonction de Carathéodory et M une fonction strictement positive et continue sur R+. Dans le cas où la fonction f est asymptotiquement linéaire à l'infini par rapport à l'inconnue u, on montre, en combinant une technique de troncature et la méthode variationnelle, que le problème admet au moins une solution positive quand la fonction M est non décroissante. Et si f(x, u) = |u|p-1 u + λg(x), où p >0, λ un paramètre réel et g une fonction de classe C1 et changeant de signe sur Ω, alors sous certaines hypothèses sur M, il existe deux réels positifs λ. et λ. tels que le problème admet des solutions positives si 0 < λ <λ. et n'admet pas de solutions positives si λ > λ.. Dans la deuxième partie, on étudie deux problèmes soulevés en dynamique des fluides. Le premier est une généralisation d'un modèle décrivant la propagation unidirectionnelle dispersive des ondes longues dans un milieu à deux fluides. En écrivant le problème sous la forme d'une équation de point fixe, on montre l'existence d'au moins une solution positive. On montre ensuite sa symétrie et son unicité. Le deuxième problème consiste à prouver l'existence de la vitesse, la pression et la température d'un fluide non newtonien, incompressible et non isotherme, occupant un domaine borné, en prenant en compte un terme de convection. L'originalité dans ce travail est que la viscosité du fluide ne dépend pas seulement de la vitesse mais aussi de la température et du module du tenseur des taux de déformations. En se basant sur la notion des opérateurs pseudo-monotones, le théorème de De Rham et celui de point fixe de Schauder, l'existence du triplet, (vitesse, pression, température) est démontré
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SARFATTI, GIULIA. « Elements of function theory in the unit ball of quaternions ». Doctoral thesis, 2013. http://hdl.handle.net/2158/806320.
Texte intégralRésumé :
The theory of regular functions over the quaternions introduced by Gentili and Struppa in 2006, already quite rich, is in continuous development. Despite their diverse peculiarities, regular functions reproduce numerous properties of holomorphic functions of one complex variable.
This Thesis is devoted to investigate properties of regular functions defined on the unit ball B of the quaternions H. As it happens in the complex case, this particular subset of H represents a special domain for the class of regular function. It is the simplest example of the most natural set of definition for a regular function, namely of a "symmetric slice domain".
Furthermore, on open balls centred at the origin, regular functions are characterized by having a power series expansion, hence they behave very nicely.
The first Chapter, starting from the very first definitions, includes all the preliminary results that will be used in the sequel.
The second Chapter discusses some properties of the modulus of regular functions, in particular how it is related with the modulus of the "regular conjugate" of a regular function. The main result presented is an analogue of the Borel-Carathéodory Theorem, a tool useful to bound the modulus of a regular function by means of the modulus of its real part.
The central part of the Thesis contains geometric theory results. The third Chapter contains the analogue of the Bohr Theorem concerning power series, together with a weaker version, that follows as in the complex case from the Borel-Carathéodory Theorem. In the fourth Chapter we prove a Bloch-Landau type theorem, showing that in some sense the image of a ball under a regular function can not be too much thin. The fifth Chapter is dedicated to Landau-Toeplitz type theorems, that study the possible shapes that the image of a regular function can assume.
The last Chapter is devoted to the study of the quaternionic Hardy spaces. We begin by the definition of the spaces H^p(B) and H^{\infty}(B), then we prove some of their basic properties. We introduce in conclusion the Corona Problem in the quaternionic setting, proving a partial statement of the Corona Theorem.
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Gabrielli, Andrea. « Defining, calculating and reasoning in Higher-Order Logic : Complex and Hypercomplex Analysis and applications ». Doctoral thesis, 2018. http://hdl.handle.net/2158/1160982.
Texte intégralRésumé :
The occasional ambiguity of traditional mathematical notations, and the increasing complexity of proofs, has led to the situation that the use of a proof-verification system is desirable if not, in some situations, unavoidable. Moreover, by merging calculation techniques and proofs, theorem provers also allow a deep interconnection of the three basic mathematical activities, that is, defining, calculating and reasoning.
In this thesis we explore such activities from different points of view, dealing with complex and hypercomplex analysis and computability theory using the HOL Light theorem prover. More precisely, the work is divided into four parts, each independent from the others.
In the first we report on a formal development of quaternions and their algebraic structure, and we discuss automatic and certified procedures to perform calculations on them.
The second part is dedicated to investigate the formalization of possible applications of our framework about quaternions. They are interesting theories on their own and, at the same time, a test for our work. In particular, we formalize basics definitions and theorems about two of the most recent and stimulating theories based on quaternions, that is, ''Slice regular quaternionic functions'' and ''Pythagorean-Hodograph curves''. Slice regular functions extend, in a suitable way, the notion of complex holomorphic function to the quaternionic case whereas, PH-curves are a class of polynomial functions with many theoretical properties and several significant computational advantages in many fields like computer-aided design (CAD), digital motion control, path planning, robotics applications and animation. The main points of the work presented in the first two parts has been published in proceedings of the 8th International Conference on Interactive Theorem Proving in Brasilia 2017.
In part three and four we consider computability as a theory on its own. In particular, we focus on two radically different models of computation (but equally important), namely ''Turing Machines'' and ''quantum computing''. We give the basic definitions and we develop two certified systems to simulate computations in such models. Moreover, by implementing the concepts of Turing machines and quantum circuits in HOL Light, we explore these different approaches formalizing some simple different problems they can solve.
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STOPPATO, CATERINA. « Regular functions of one quaternionic variable ». Doctoral thesis, 2010. http://hdl.handle.net/2158/1034111.
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Литвин, О. М., О. Г. Литвин et О. О. Литвин. « Method of Calculating Fourier Coefficients of Three Variable Functions Using Tomogram ». Thesis, 2019. http://openarchive.nure.ua/handle/document/9457.
Texte intégralRésumé :
A method for calculating Fourier coefficients of functions of three variables using tomograms is proposed and
investigated. Earlier Lytvyn O.M. proposed and introduced the method of calculating Fourier coefficients of the function of two variables using integrals of this function along a given system of direct. It is believed that these integrals - projections or projection data arrive from a computer tomograph.
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DAI, XIAN-GUAN, et 戴顯權. « A study on suppressed variable permutation and complementation transformations on boolean functions ». Thesis, 1989. http://ndltd.ncl.edu.tw/handle/14534163069016445799.
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Lin, Jang-Hung, et 林建宏. « Fuzzy Sliding Mode Controller Design With Variable Sliding Surface And Adjustable Membership Functions ». Thesis, 1999. http://ndltd.ncl.edu.tw/handle/79621800953037122373.
Texte intégralRésumé :
碩士大同工學院
電機工程研究所
87
In this thesis, a simple design method is applied to regulate the membership functions of fuzzy sliding mode controller for the control of second order system. On the other hand, we will apply a variable sliding surface to design the fuzzy sliding mode controller, instead of the fixed sliding surface, which has the robustness against parameter variations and extraneous disturbances. At first, a kind of experimental design method, called Taguchi’s method, is introduced. We can give each design factor of the membership functions three values and then find out the best combination of the values of all design factors that can come out the best performance under these selectable values. Therefore, we can regulate the membership functions by this method. Second, we will change the fixed parameter of sliding surface to time-varying one by Takagi-Sugeno fuzzy algorithm. This design method has better performance than the conventional method (with fixed parameter) in reaching time, and getting better performance even with parameter variation and extraneous disturbance. Finally, a hydraulic servo system is proposed to simulate. It is simulated by using four different combinations of the membership function values in order to contrast with the performance which simulates using the best combination of the membership function values by our proposed fuzzy sliding mode controller.
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« Students' Ways of Thinking about Two-Variable Functions and Rate of Change in Space ». Doctoral diss., 2012. http://hdl.handle.net/2286/R.I.14562.
Texte intégralRésumé :
abstract: This dissertation describes an investigation of four students' ways of thinking about functions of two variables and rate of change of those two-variable functions. Most secondary, introductory algebra, pre-calculus, and first and second semester calculus courses do not require students to think about functions of more than one variable. Yet vector calculus, calculus on manifolds, linear algebra, and differential equations all rest upon the idea of functions of two (or more) variables. This dissertation contributes to understanding productive ways of thinking that can support students in thinking about functions of two or more variables as they describe complex systems with multiple variables interacting. This dissertation focuses on modeling the way of thinking of four students who participated in a specific instructional sequence designed to explore the limits of their ways of thinking and in turn, develop a robust model that could explain, describe, and predict students' actions relative to specific tasks. The data was collected using a teaching experiment methodology, and the tasks within the teaching experiment leveraged quantitative reasoning and covariation as foundations of students developing a coherent understanding of two-variable functions and their rates of change. The findings of this study indicated that I could characterize students' ways of thinking about two-variable functions by focusing on their use of novice and/or expert shape thinking, and the students' ways of thinking about rate of change by focusing on their quantitative reasoning. The findings suggested that quantitative and covariational reasoning were foundational to a student's ability to generalize their understanding of a single-variable function to two or more variables, and their conception of rate of change to rate of change at a point in space. These results created a need to better understand how experts in the field, such as mathematicians and mathematics educators, thinking about multivariable functions and their rates of change.Dissertation/Thesis
Ph.D. Mathematics 2012
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Belock, Julie. « Random variable dilation equations in R[superscript d] and the stability of scaling functions / ». Diss., 1998. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:9914424.
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Medalha, Samuel João Baltazar. « Algebras of Convolution Type Operators on Weighted Variable Lebesgue Spaces ». Master's thesis, 2021. http://hdl.handle.net/10362/135865.
Texte intégralRésumé :
We prove a version of the Riesz-Thorin interpolation theorem for some types of weighted
variable Lebesgue spaces. In order to do this we use the theory developed by Calderón in
his 1964 article, together with some Banach function space theory.
Using our version of the Riesz-Thorin theorem, we prove a version of the Stechkin
inequality forweighted variable Lebesgue spaces, allowing us to define algebras of Fourier
multipliers arising from functions of bounded variation.
After analyzing the invertibility of Fourier convolution operators with piecewise continuous
symbols, we shift our attention to slowly oscillating Fourier multipliers, finishing
with a proof that the image in the Calkin algebra of the algebra of convolution type
operators with slowly oscillating data is commutative.Provamos uma versão do teorema de interpolação de Riesz-Thorin para alguns tipos de espaços de Lebesgue com expoente variável e peso. De forma a atingir este objectivo, usamos a teoria desenvolvida por Calderón no seu artigo de 1964. Usando a versão do teorema de Riesz-Thorin obtida, provamos uma versão da desigualdade de Stechkin para espaços de Lebesgue com expoente variável e peso. Isto permite-nos definir álgebras de multiplicadores de Fourier associados a funções de variação limitada. Após analisada a invertibilidade dos operadores de convolução com símbolos contínuos por troços, deslocamos a nossa atenção para multiplicadores de Fourier fracamente oscilantes. Terminamos com a prova de que a imagem na álgebra de Calkin da álgebra de operadores tipo convolução com dados fracamente oscilantes é comutativa.
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Wu, Meng-Shiun, et 吳孟訓. « Exploring the Antecedents of Mentoring Functions and Their Effects on Proteges Job-Related Output─Role Stress as the Mediating Variable ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/67164151059802949695.
Texte intégralRésumé :
碩士國立屏東科技大學
企業管理系所
97
As human and intellectual capital have become more essential to organizational effectiveness and competitive advantages under the challenging environment, mentoring programs have become an important means to accelerate the protégé’s socialization and learning process. This strategic issue has received an increasing attentions in academy and practitioners. Although, the previous literatures have expanded our insights on this field, many theorists and researchers recommend that an integrated framework should be empirically examined to have a broader and deeper understanding. This study will try to construct a more integrated framework, in which the causal linkage structure within the variables of mentoring functions, their antecedents （which include mentor’s characteristics and protégé’s negative experience）, the mediating effect of role stress and protégé’s job related outputs will be explored. The statistical method of LISREL will be adopted in this part. This study is an empirical research. Structured questionnaires will be designed for mentor and protégé respondent respectively from two different sources: adult students enrolled in a master’s of management programme in universities. After a clear definition of mentor program is given, qualified respondents will be drawn. The questionnaires will be given on the spot and should be returned by attached posted mail before deadline. The result of this study conclusions indicate that (1) the mentor’s leadership, motivation, expect benefit, social psychology has positive to impact on mentoring function. (2) protégé's negative mentoring experiences has negative to impact on mentoring function. (3) mentoring function has negative to impact on role stress. (4) work output has negative to impact on role stress.
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Tang, Ming-Jmeng, et 唐明正. « The impact of mentoring functions on job performance using learning performance as an intermediary variable : The moderating effect of self-efficacy ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/14066153682101308585.
Texte intégralRésumé :
碩士國立屏東科技大學
資訊管理系所
100
In recent years, research on learning performance of mentoring functions calls attentions from the academic and the practice. Related research on mentoring functions including vocational supports, psychosocial supports, and role modeling on job performance has been widely discussed. However, research on the impact of mentoring functions on job performance using learning performance as an intermediary variable and self-efficacy as a moderator has not been found in related research. Based on the above discussion, this research develops a framework that uses learning performance as an intermediary variable and self-efficacy as a moderating variable to investigate the influences of mentoring functions on job performance. A survey of 547 respondents chosen from vocational soldiers of a military training center located in southern Taiwan. The findings of this research are shown as follows: (1) the impact of mentoring functions on learning performance: (a) vocational supports has insignificant influence on related job learning and individual technical development; (b) psychosocial supports and role modeling has significant influence on related job learning and individual technical development. (2) the impact of mentoring functions on job performance: (a) vocational supports has insignificant influence on work efficiency and work quality; (b) psychosocial supports and role modeling has significant influence on work efficiency, but has insignificant influence on work quality. (3) the impact of learning performance on job performance: (a) related job learning has insignificant influence on work efficiency and work quality; (b) individual technical development has significant influence on work efficiency and work quality. Based on the results of research, it is suggested that persons in charge of training centers shall strength the psychosocial supports, and role modeling of mentoring functions to improve job performance through the learning performance of individual technical development. Furthermore, the findings of this research include self-efficacy has moderating effects of the mentoring functions on learning performance, self-efficacy has moderating effects of the learning performance on job performance, and self-efficacy does not have moderating effects of the mentoring functions on job performance. Based on the findings of this research, it is suggested that persons in charge of military training centers shall adopt proper learning method to train the learners according to the learner’s level of individual self-efficacy. In summary, the research findings mentioned above can provide useful suggestions for military training centers in carrying out training activities and references for making an important decision.
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CHANG, YA-LING, et 張雅苓. « The effect of mentoring functions on innovative behaviors of R&D engineers of new high-tech companies – Knowledge sharing as a mediating variable ». Thesis, 2018. http://ndltd.ncl.edu.tw/handle/r6vw9q.
Texte intégralRésumé :
碩士國立臺北科技大學
技術及職業教育研究所
107
In the era of knowledge economy, high-tech innovative companies have become important indexes and projects of future national development. These industries have to ensure the competitive advantage and sustainable development, which lie on the function of mentoring in the company, employee innovation behavior, knowledge sharing and other factors. The mentioned core abilities can effectively promote the growth of organization through communication and coordination. The purpose of this study is to investigate the correlation between mentoring function and employee innovation behavior, as well as the mediating effect of knowledge sharing. The research adopts an investigation method to the employees in those companies which were listed at stock exchange market for the first time, at over-the-counter market and at emerging stock market during March 2014 to September 2017 in Taiwan stock market. 1970 questionnaries were issued and 202 valid questionnaries were collected. After analyzing the received data, the results are showed as follows:1.The employees’ perception of mentoring function in occupation and role model is good, but that in society support is just passable.2.The employees’ perception of knowledge sharing in offering and acquiring knowledge is good.3.The employees’ perception of innovation behavior is good.4.Society support and role model in mentoring function have a significant positive influence on the employees’ innovation behavior; occupation function has a significant negative influence.5.Occupation and role model in mentoring function have a significant positive influence on the employees’ knowledge sharing.6.The employees’ knowledge acquiring ability has a significant positive influence on innovation behavior.7.The employees’ knowledge sharing has a mediating effects between mentoring function and innovation behavior.Finally, this thesis proposes the conclusion of the study and the practice meaning based on the research results, and the suggestion to future studies.
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Bartel, Joseph. « A study on the effects of multicollinearity, autocorrelation and four sampling designs on the predictive ability of the 1994 and 1995 variable-exponent taper functions ». Thesis, 1999. http://hdl.handle.net/2429/9003.
Texte intégralRésumé :
In British Columbia, government, industry and consulting firms have used taper functions
since the late sixties. Most recently, Kozak's (1988) variable exponent model has been used since
1989. One practical problem with the model is that, it does not estimate total or merchantable
volume without bias. These biases were found to be more pronounced for red cedar (Thuja
plicata Donn ex D.Don) and western hemlock (Tsuga heterophylla (raf). Sarg.). Because of this
problem, a second equation known as the 1994 equation was developed. However, reviewers
identified some theoretical problems concerning multicollinearity and autocorrelation in the 1994
equation. These prompted the development of a third equation that possesses a lesser amount of
multicollinearity referred to as the 1995 equation.
The three principal objectives of this research were: (1) to study the effects of
multicollinearity and autocorrelation on the predictive ability of the 1994 and 1995 variableexponent
taper functions; (2) to study the effects of four sampling strategies on the predictive
ability of the 1994 and 1995 taper equations; and (3) to examine the possibility of localizing the
1994 taper equations.
The effects of multicollinearity and autocorrelation and the four sampling designs were
studied using Monte Carlo simulations. The results of the study indicated that the presence of
severe multicollinearity and autocorrelation in the data did not seriously affect the predictive
ability of the equations.
Stratified random sampling, with equal allocation of observations selected from each
stratum, gave the smallest variability of the estimated coefficients compared to simple random
sampling, and stratified random sampling, with the number of samples proportional to the size of
the strata. However, the average estimated regression coefficients were somewhat different from the population parameters.Therefore, simple random sampling is recommended for selecting
trees from the population if the main objective is the estimation of the population parameters. If
the equations are to be used for prediction, then a wider range of the data (stratified sampling)
should be used.
The results indicated that no adjustment or scaling is required for the western hemlock
equation for the two subzones studied.