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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Elliptiska kurvor och Lenstras faktoriseringsalgoritm / Elliptic Curves and Lenstra's Factorization Algorithm

Jonsson, Johan January 2009 (has links)
En elliptisk kurva består av nollställena till ett kubisk polynom i två variabler, sådant att det existerar åtminstone en punkt på kurvan och kurvan är icke-singulär. Punkterna på en sådan kurva bildar en abelsk grupp och olika egenskaper hos dessa grupper beskrivs i den här uppsatsen. Bland annat presenteras Mordell-Weils sats som säger att en elliptisk kurva över en talkropp är en ändligt genererad grupp. Nagell-Lutz sats ger nödvändiga villkor för att en punkt på en rationell elliptisk kurva ska ha ändlig ordning. Resultatet att en elliptisk kurva över de komplexa talen är isomorf med en torus presenteras också. Tillämpningen heltalsfaktorisering presenteras genom en beskrivning av Lenstras algoritm. En implementation av denna algoritm i form av ett datorprogram görs och denna implementation jämförs med den triviala algoritmen för heltalsfaktorisering. / An elliptic curve consists of the zeros of a cubic polynomial i two variables, such that there exists at least one point on the curve and the curve is non-singular. The points on such a curve form an abelian group and various properties of these groups are described in this thesis. Among other things the Mordell-Weil theorem, which states that an elliptic curve over a number field is a finitely generated group, is presented. The Nagell-Lutz theorem gives necessary conditions for a point on a rational elliptic curve to have finite order. Another presented result is that an elliptic curve over the complex numbers is a torus. The application of elliptic curves in integer factorization is presented by describing Lenstra's algorithm. A computer program implementing this algorithm is made and this implementation is compared to the trivial algorithm for integer factorization.
132

Asymptotic analysis of an ε-Stokes problem with Dirichlet boundary conditions

Matsui, Kazunori January 2019 (has links)
In this thesis, we propose an ε-Stokes problem connecting the Stokes problem and the corresponding pressure-Poisson equation using one pa- rameter ε > 0. We prove that the solution to the ε-Stokes problem, converges as ε tends to 0 or ∞ to the Stokes and pressure-Poisson prob- lem, respectively. Most of these results are new. The precise statements of the new results are given in Proposition 3.5, Theorem 4.1, Theorem 5.2, and Theorem 5.3. Numerical results illustrating our mathematical results are also presented. / STINT (DD2017-6936) "Mathematics Bachelor Program for Efficient Computations"
133

Influence of bilingualism on simple arithmetic

Unknown Date (has links)
It has been widely hypothesized that while doing arithmetic, individuals use two distinct routes for phonological output. A direct route is used for exact arithmetic which is language dependent, while an indirect route is used during arithmetic approximation and thought to be language independent. The arithmetic double route has been incorporated on the triple- code model that consists of visual arabic code for identifying strings of digits, magnitude code for knowledge in numeral quantities, and verbal code for rote arithmetic fact. Our goal is to investigate whether language experience has an effect on the processing of exact/approximation math using bilingual participants who have access to two languages, using a theoretical arithmetic processing model, which has been validated across many studies. We have measured the two groups (monolinguals/bilinguals) processing speed for completing the two tasks (Exact/Approximation) in two codes (Arabic digit/Verbal). We hypothesized a faster reaction time in exact arithmetic task in compared to approximation in accordance with the triple-code model. We alsoexpected a main effect for the task (Exact vs.Approximation) independent of the input code when the stimulus was presented in either Arabic digit and/or verbal codes. Our results show exact arithmetic is faster than approximation of arithmetic facts in all codes supporting earlier theories. Also, there was no significant difference in processing speed between monolinguals and bilinguals when performing the arithmetic task in either Arabic and/or verbal codes. In addition, our investigation suggests a modification to the triple-code model when interpreting arithmetic facts in verbal code due to interference of two languages with bilingual participants. Additions to the model can be suggested when the stimulus is expressed in verbal code for visual identification, which may cause interference in bilinguals leading to a first language advantage due to language experience. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
134

Forever Young : Convolution Inequalities in Weighted Lorentz-type Spaces

Křepela, Martin January 2014 (has links)
This thesis is devoted to an investigation of boundedness of a general convolution operator between certain weighted Lorentz-type spaces with the aim of proving analogues of the Young convolution inequality for these spaces. Necessary and sufficient conditions on the kernel function are given, for which the convolution operator with the fixed kernel is bounded between a certain domain space and the weighted Lorentz space of type Gamma. The considered domain spaces are the weighted Lorentz-type spaces defined in terms of the nondecreasing rearrangement of a function, the maximal function or the difference of these two quantities. In each case of the domain space, the corresponding Young-type convolution inequality is proved and the optimality of involved rearrangement-invariant spaces in shown. Furthermore, covering of the previously existing results is also discussed and some properties of the new rearrangement-invariant function spaces obtained during the process are studied. / <p>Paper II was a manuscript at the time of the defense.</p>
135

A value estimation approach to Iri-Imai's method for constrained convex optimization.

January 2002 (has links)
Lam Sze Wan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 93-95). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background --- p.4 / Chapter 3 --- Review of Iri-Imai Algorithm for Convex Programming Prob- lems --- p.10 / Chapter 3.1 --- Iri-Imai Algorithm for Convex Programming --- p.11 / Chapter 3.2 --- Numerical Results --- p.14 / Chapter 3.2.1 --- Linear Programming Problems --- p.15 / Chapter 3.2.2 --- Convex Quadratic Programming Problems with Linear Inequality Constraints --- p.17 / Chapter 3.2.3 --- Convex Quadratic Programming Problems with Con- vex Quadratic Inequality Constraints --- p.18 / Chapter 3.2.4 --- Summary of Numerical Results --- p.21 / Chapter 3.3 --- Chapter Summary --- p.22 / Chapter 4 --- Value Estimation Approach to Iri-Imai Method for Con- strained Optimization --- p.23 / Chapter 4.1 --- Value Estimation Function Method --- p.24 / Chapter 4.1.1 --- Formulation and Properties --- p.24 / Chapter 4.1.2 --- Value Estimation Approach to Iri-Imai Method --- p.33 / Chapter 4.2 --- "A New Smooth Multiplicative Barrier Function Φθ+,u" --- p.35 / Chapter 4.2.1 --- Formulation and Properties --- p.35 / Chapter 4.2.2 --- "Value Estimation Approach to Iri-Imai Method by Us- ing Φθ+,u" --- p.41 / Chapter 4.3 --- Convergence Analysis --- p.43 / Chapter 4.4 --- Numerical Results --- p.46 / Chapter 4.4.1 --- Numerical Results Based on Algorithm 4.1 --- p.46 / Chapter 4.4.2 --- Numerical Results Based on Algorithm 4.2 --- p.50 / Chapter 4.4.3 --- Summary of Numerical Results --- p.59 / Chapter 4.5 --- Chapter Summary --- p.60 / Chapter 5 --- Extension of Value Estimation Approach to Iri-Imai Method for More General Constrained Optimization --- p.61 / Chapter 5.1 --- Extension of Iri-Imai Algorithm 3.1 for More General Con- strained Optimization --- p.62 / Chapter 5.1.1 --- Formulation and Properties --- p.62 / Chapter 5.1.2 --- Extension of Iri-Imai Algorithm 3.1 --- p.63 / Chapter 5.2 --- Extension of Value Estimation Approach to Iri-Imai Algo- rithm 4.1 for More General Constrained Optimization --- p.64 / Chapter 5.2.1 --- Formulation and Properties --- p.64 / Chapter 5.2.2 --- Value Estimation Approach to Iri-Imai Method --- p.67 / Chapter 5.3 --- Extension of Value Estimation Approach to Iri-Imai Algo- rithm 4.2 for More General Constrained Optimization --- p.69 / Chapter 5.3.1 --- Formulation and Properties --- p.69 / Chapter 5.3.2 --- Value Estimation Approach to Iri-Imai Method --- p.71 / Chapter 5.4 --- Numerical Results --- p.72 / Chapter 5.4.1 --- Numerical Results Based on Algorithm 5.1 --- p.73 / Chapter 5.4.2 --- Numerical Results Based on Algorithm 5.2 --- p.76 / Chapter 5.4.3 --- Numerical Results Based on Algorithm 5.3 --- p.78 / Chapter 5.4.4 --- Summary of Numerical Results --- p.86 / Chapter 5.5 --- Chapter Summary --- p.87 / Chapter 6 --- Conclusion --- p.88 / Bibliography --- p.93 / Chapter A --- Search Directions --- p.96 / Chapter A.1 --- Newton's Method --- p.97 / Chapter A.1.1 --- Golden Section Method --- p.99 / Chapter A.2 --- Gradients and Hessian Matrices --- p.100 / Chapter A.2.1 --- Gradient of Φθ(x) --- p.100 / Chapter A.2.2 --- Hessian Matrix of Φθ(x) --- p.101 / Chapter A.2.3 --- Gradient of Φθ(x) --- p.101 / Chapter A.2.4 --- Hessian Matrix of φθ (x) --- p.102 / Chapter A.2.5 --- Gradient and Hessian Matrix of Φθ(x) in Terms of ∇xφθ (x) and∇2xxφθ (x) --- p.102 / Chapter A.2.6 --- "Gradient of φθ+,u(x)" --- p.102 / Chapter A.2.7 --- "Hessian Matrix of φθ+,u(x)" --- p.103 / Chapter A.2.8 --- "Gradient and Hessian Matrix of Φθ+,u(x) in Terms of ∇xφθ+,u(x)and ∇2xxφθ+,u(x)" --- p.103 / Chapter A.3 --- Newton's Directions --- p.103 / Chapter A.3.1 --- Newton Direction of Φθ (x) in Terms of ∇xφθ (x) and ∇2xxφθ(x) --- p.104 / Chapter A.3.2 --- "Newton Direction of Φθ+,u(x) in Terms of ∇xφθ+,u(x) and ∇2xxφθ,u(x)" --- p.104 / Chapter A.4 --- Feasible Descent Directions for the Minimization Problems (Pθ) and (Pθ+) --- p.105 / Chapter A.4.1 --- Feasible Descent Direction for the Minimization Prob- lems (Pθ) --- p.105 / Chapter A.4.2 --- Feasible Descent Direction for the Minimization Prob- lems (Pθ+) --- p.107 / Chapter B --- Randomly Generated Test Problems for Positive Definite Quadratic Programming --- p.109 / Chapter B.l --- Convex Quadratic Programming Problems with Linear Con- straints --- p.110 / Chapter B.l.1 --- General Description of Test Problems --- p.110 / Chapter B.l.2 --- The Objective Function --- p.112 / Chapter B.l.3 --- The Linear Constraints --- p.113 / Chapter B.2 --- Convex Quadratic Programming Problems with Quadratic In- equality Constraints --- p.116 / Chapter B.2.1 --- The Quadratic Constraints --- p.117
136

A lagrangian reconstruction of a class of local search methods.

January 1998 (has links)
by Choi Mo Fung Kenneth. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 105-112). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Constraint Satisfaction Problems --- p.2 / Chapter 1.2 --- Constraint Satisfaction Techniques --- p.2 / Chapter 1.3 --- Motivation of the Research --- p.4 / Chapter 1.4 --- Overview of the Thesis --- p.5 / Chapter 2 --- Related Work --- p.7 / Chapter 2.1 --- Min-conflicts Heuristic --- p.7 / Chapter 2.2 --- GSAT --- p.8 / Chapter 2.3 --- Breakout Method --- p.8 / Chapter 2.4 --- GENET --- p.9 / Chapter 2.5 --- E-GENET --- p.9 / Chapter 2.6 --- DLM --- p.10 / Chapter 2.7 --- Simulated Annealing --- p.11 / Chapter 2.8 --- Genetic Algorithms --- p.12 / Chapter 2.9 --- Tabu Search --- p.12 / Chapter 2.10 --- Integer Programming --- p.13 / Chapter 3 --- Background --- p.15 / Chapter 3.1 --- GENET --- p.15 / Chapter 3.1.1 --- Network Architecture --- p.15 / Chapter 3.1.2 --- Convergence Procedure --- p.18 / Chapter 3.2 --- Classical Optimization --- p.22 / Chapter 3.2.1 --- Optimization Problems --- p.22 / Chapter 3.2.2 --- The Lagrange Multiplier Method --- p.23 / Chapter 3.2.3 --- Saddle Point of Lagrangian Function --- p.25 / Chapter 4 --- Binary CSP's as Zero-One Integer Constrained Minimization Prob- lems --- p.27 / Chapter 4.1 --- From CSP to SAT --- p.27 / Chapter 4.2 --- From SAT to Zero-One Integer Constrained Minimization --- p.29 / Chapter 5 --- A Continuous Lagrangian Approach for Solving Binary CSP's --- p.33 / Chapter 5.1 --- From Integer Problems to Real Problems --- p.33 / Chapter 5.2 --- The Lagrange Multiplier Method --- p.36 / Chapter 5.3 --- Experiment --- p.37 / Chapter 6 --- A Discrete Lagrangian Approach for Solving Binary CSP's --- p.39 / Chapter 6.1 --- The Discrete Lagrange Multiplier Method --- p.39 / Chapter 6.2 --- Parameters of CSVC --- p.43 / Chapter 6.2.1 --- Objective Function --- p.43 / Chapter 6.2.2 --- Discrete Gradient Operator --- p.44 / Chapter 6.2.3 --- Integer Variables Initialization --- p.45 / Chapter 6.2.4 --- Lagrange Multipliers Initialization --- p.46 / Chapter 6.2.5 --- Condition for Updating Lagrange Multipliers --- p.46 / Chapter 6.3 --- A Lagrangian Reconstruction of GENET --- p.46 / Chapter 6.4 --- Experiments --- p.52 / Chapter 6.4.1 --- Evaluation of LSDL(genet) --- p.53 / Chapter 6.4.2 --- Evaluation of Various Parameters --- p.55 / Chapter 6.4.3 --- Evaluation of LSDL(max) --- p.63 / Chapter 6.5 --- Extension of LSDL --- p.66 / Chapter 6.5.1 --- Arc Consistency --- p.66 / Chapter 6.5.2 --- Lazy Arc Consistency --- p.67 / Chapter 6.5.3 --- Experiments --- p.70 / Chapter 7 --- Extending LSDL for General CSP's: Initial Results --- p.77 / Chapter 7.1 --- General CSP's as Integer Constrained Minimization Problems --- p.77 / Chapter 7.1.1 --- Formulation --- p.78 / Chapter 7.1.2 --- Incompatibility Functions --- p.79 / Chapter 7.2 --- The Discrete Lagrange Multiplier Method --- p.84 / Chapter 7.3 --- A Comparison between the Binary and the General Formulation --- p.85 / Chapter 7.4 --- Experiments --- p.87 / Chapter 7.4.1 --- The N-queens Problems --- p.89 / Chapter 7.4.2 --- The Graph-coloring Problems --- p.91 / Chapter 7.4.3 --- The Car-Sequencing Problems --- p.92 / Chapter 7.5 --- Inadequacy of the Formulation --- p.94 / Chapter 7.5.1 --- Insufficiency of the Incompatibility Functions --- p.94 / Chapter 7.5.2 --- Dynamic Illegal Constraint --- p.96 / Chapter 7.5.3 --- Experiments --- p.97 / Chapter 8 --- Concluding Remarks --- p.100 / Chapter 8.1 --- Contributions --- p.100 / Chapter 8.2 --- Discussions --- p.102 / Chapter 8.3 --- Future Work --- p.103 / Bibliography --- p.105
137

A nonparametric multiclass partitioning method for classification

Gelfand, Saul B. (Saul Brian) January 1982 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Includes bibliographical references. / by Saul Brian Gelfand. / M.S.
138

Evolution equations and vector-valued Lp spaces: Strichartz estimates and symmetric diffusion semigroups.

Taggart, Robert James, Mathematics & Statistics, Faculty of Science, UNSW January 2008 (has links)
The results of this thesis are motivated by the investigation of abstract Cauchy problems. Our primary contribution is encapsulated in two new theorems. The first main theorem is a generalisation of a result of E. M. Stein. In particular, we show that every symmetric diffusion semigroup acting on a complex-valued Lebesgue space has a tensor product extension to a UMD-valued Lebesgue space that can be continued analytically to sectors of the complex plane. Moreover, this analytic continuation exhibits pointwise convergence almost everywhere. Both conclusions hold provided that the UMD space satisfies a geometric condition that is weak enough to include many classical spaces. The theorem is proved by showing that every symmetric diffusion semigroup is dominated by a positive symmetric diffusion semigoup. This allows us to obtain (a) the existence of the semigroup's tensor extension, (b) a vector-valued version of the Hopf--Dunford--Schwartz ergodic theorem and (c) an holomorphic functional calculus for the extension's generator. The ergodic theorem is used to prove a vector-valued version of a maximal theorem by Stein, which, when combined with the functional calculus, proves the pointwise convergence theorem. The second part of the thesis proves the existence of abstract Strichartz estimates for any evolution family of operators that satisfies an abstract energy and dispersive estimate. Some of these Strichartz estimates were already announced, without proof, by M. Keel and T. Tao. Those estimates which are not included in their result are new, and are an abstract extension of inhomogeneous estimates recently obtained by D. Foschi. When applied to physical problems, our abstract estimates give new inhomogeneous Strichartz estimates for the wave equation, extend the range of inhomogeneous estimates obtained by M. Nakamura and T. Ozawa for a class of Klein--Gordon equations, and recover the inhomogeneous estimates for the Schr??dinger equation obtained independently by Foschi and M. Vilela. These abstract estimates are applicable to a range of other problems, such as the Schr??dinger equation with a certain class of potentials.
139

En learning study i geometriEn learning study i geometri : Hur elever i årskurs 2 kan lära sig förstå skillnaderna och likheterna mellan kvadrat, rektangel, romb och parallellogram / A Learning Study in Geometry : How pupils in the second grade can understand and learn the differences and similarities between square, rectangle, rhomb and parallelogram

Billing, Annika, Linton, Lotta January 2009 (has links)
<p>Syftet med denna studie har varit att hitta de kritiska aspekterna för eleverna att lära sig särskilja fyrhörningarna, kvadrat, rektangel, romb och parallellogram. Vidare har vi undersökt hur undervisningen kan genomföras för att eleverna ska ha möjlighet att känna igen och korrekt namnge fyrhörningarna samt hur läraren kan ge eleverna möjlighet att erfara variation av vårt valda lärandeobjekt. För att besvara ovanstående frågor har vi använt oss av learning study som forskningsmetod. De 3 momenten som har ingått i vår studie är förtest, lektion och eftertest. Studien har genomförts i årskurs 2 i 3 relativt kunskapshomogena elevgrupper som vi i studien kallar grupp 1, 2 och 3. Alla grupper har efter genomförd undervisning förbättrat sina kunskaper avsevärt. Grupp 1 var den grupp som hade den största kunskapsökningen samt visade det totalt bästa resultatet.</p>
140

Hedging strategy for an option on commodity market

Tkachev, Ilya January 2010 (has links)
<p>In this work we consider the methods of pricing and hedging an option on the forward commodity market described by the multi-factor diffusion model. In the previous research there were presented explicit valuation formulas for standard European type options and simulation schemes for other types of options. However, hedging strategies were not developed in the available literature. Extending known results this work gives analytical formulas for the price of American, Asian and general European options. Moreover, for all these options hedging strategies are presented. Using these results the dynamics of the portfolio composed of options on futures with different maturities is studied on a commodity market.</p>

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