by Chin Pang Cheung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 38-39). / Abstracts in English and Chinese. / Chapter 1 --- Main Results and Introduction --- p.4 / Chapter 1.1 --- Preliminaries --- p.5 / Chapter 2 --- The Linearized Operator in the Weighted Sobolev Spaces --- p.8 / Chapter 2.1 --- Weighted Sobolev Space and Some Useful Properties --- p.8 / Chapter 2.2 --- The Linearized Operator --- p.10 / Chapter 3 --- Reduction to Finite Dimensions --- p.19 / Chapter 4 --- Reduced Problem --- p.27 / Chapter 4.1 --- Proof of Theorem 1.1 --- p.27 / Chapter 4.2 --- Asymptotic Behavior of uE --- p.34 / Bibliography

Lam, Wai Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 55-56). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Yeung Sik-ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 39-42). / Chapter 1 --- Introduction and Statement of the Results --- p.3 / Chapter 2 --- Maximum Principles and Comparison Theorems --- p.12 / Chapter 3 --- Pohozaev Identity and Symmetry for p-Laplacian when 1<p<2 --- p.18 / Chapter 4 --- Singularly Perturbed p-Laplacian Equation --- p.23 / Chapter 5 --- Appendix --- p.31 / Bibliography --- p.39

對流佔優擴散問題一直是一個俱有挑戰性的問題。眾所週知，解可能在邊界或者內部表現出局部斷層。傳統的數值解法在解決對流佔優擴散問題時不夠穩定和精確。因此有很多空間穩定技巧被提出和學習。 / 在這篇論文中，我們設計了一個全變分規則化方法來解對流佔優擴散方程。首先，選取一個較小的測試函數空間構造一個欠定模型。然後，通過附加條件最小化全變分來計算唯一解。這個想法是基於離散化解雙曲形偏微分方程的全變分遞減原理。為了實現這個全變分規則化方法，我們需要找出相應的拉格郎日方程的最優條件，並當做時間依賴方程進行求解。論文中涉及了三個運算符拆分方法，Peaceman-Rachford方法，Douglas-Rachford方法和Theta方法。數值實驗證明我們的方法可以準確的描繪出對流佔優擴散問題的邊界和內部斷層現象，因此可以在擴散系數很小的時候提供可靠的數值結果。 / The convection-dominated diffusion problem has been a challenge problem for a long time. It is well known that the solution may exhibit localized layer on the boundary or in the interior. Conventional numerical schemes for the convection-dominated diffusion problem are lacking in both stability and accuracy. Therefore many spatial stabilization techniques have been proposed and studied. / In this thesis, we devise a TV regularization method for solving convection-dominated diffusion equations. First, we form an underdetermined system by choosing a small test function space. Then, we find the unique solution by minimizing the total variation. The idea is based on the fact that total variation diminishing (TVD) is a property of certain discretization schemes used to solve hyperbolic partial differential equation. To implement this TV regularization approach, we find the optimality condition of the corresponding Lagrange function for the minimization problem, and then solve it as a time dependent problem. Three operator splitting methods, the Peaceman-Rachford method, the Douglas-Rachford method and the Theta scheme are studied. The numerical experiments demonstrate that our scheme can accurately capture the boundary and internal layer for the convection-dominated problem, and therefore provide reliable numerical result for small diffusivity. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Qi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 56-[58]). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.6 / Chapter 2 --- TV scheme --- p.9 / Chapter 2.1 --- TV regularization --- p.9 / Chapter 2.1.1 --- The underdetermined system --- p.10 / Chapter 2.1.2 --- The minimization problem --- p.10 / Chapter 2.2 --- The optimality conditions --- p.11 / Chapter 2.3 --- Discrete version --- p.14 / Chapter 3 --- Numerical schemes --- p.17 / Chapter 3.1 --- Peachment-Rachford method --- p.17 / Chapter 3.2 --- Douglas-Rachford method --- p.18 / Chapter 3.3 --- Theta scheme --- p.19 / Chapter 3.4 --- Two systems --- p.22 / Chapter 3.4.1 --- System 1 --- p.23 / Chapter 3.4.2 --- System 2 --- p.25 / Chapter 3.5 --- Matrix representation --- p.26 / Chapter 4 --- Numerical examples --- p.29 / Chapter 4.1 --- Scenario --- p.30 / Chapter 4.1.1 --- Initial condition --- p.30 / Chapter 4.1.2 --- Notation --- p.30 / Chapter 4.1.3 --- Parameter --- p.31 / Chapter 4.2 --- Experiment 1 --- p.32 / Chapter 4.3 --- Experiment 2 --- p.38 / Chapter 4.4 --- Experiment 3 --- p.42 / Chapter 4.5 --- Experiment 4 --- p.48 / Chapter 5 --- Conclusion --- p.55

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Analisa-se numericamente o comportamento das soluções da equação X(t) + X(t) = f(X(t-)) para f(X) = A X (l-X), em função dos parâmetros , A. Constroem-se as curvas de duplicação de período no espaço de parâmetros para uma determinada condição inicial, que assegura um determinado tipo de solução assintótica (pertencente ao \"ramo 1\"). Verifica-se a conjectura de que a \"rota para o caos\" neste ramo 1\", possa ser a rota de Feigenbaum. Realça-se o fato de que esta equação, para alguns valores de , A, possui diversos atratores. Estuda-se a organização das soluções globais e limitadas da equação acima em \"ramos\" (certos domínios de soluções), e faz-se uma análise das relações entre as soluções dos diversos \"ramos\". Constata-se que uma cascata de duplicação de período no ramo 1, implica em cascatas de duplicação, ao menos parciais, em outros ramos. Para a equação acima com f(X) = A X (l-X), apresentam-se algumas soluções sob a forma de série, parcialmente computáveis sobre a reta, e faz-se uma aplicação de um resultado acerca da estabilidade do ramo 1 no caso f(X) = A sen(X-C), que corresponde a uma equação da ótica. / Numerical analysis are made of the behavior of the solutions of the equation X(t) + X(t) = f(X(t-)) for f(X) = A X (1 - X), as function of the parameters , A. Period-doubling bifurcation curves are constructed in the parameter space for some particular initial conditions, that insures a certain asymptotic behavior of the solutions (it belongs to \"branch 1\"). It is verified the conjecture that the \"route to chaos\" in the \"branch 1\" may be the Feigenbaum\'s route. The organization of the global and bounded solutions of the above equation in branches (certain domains of solutions) is studied. An analysis is made of the relations between solutions belonging to different branches. It is verified that the existence of a full period-doubling cascade in the branch 1 implies the existence, at least partially, of period-doubling cascade in other branches. It is noted that, for some values of (, A), the equation has many attractors. Some series expansions of solutions of the above equation are presented. These series expantions may be partially computed on the set R. An application of a result about the \"stability\" of branch 1 is made for the case f(X) = A sin(X-C), used to describe an optical system.

Cheung Ka Luen. / "December 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 95-101). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Finally, we get various estimates on the rupture set of the solution to the Thin Film type equations. / In the first part of the thesis, we focus on the semilinear equations with supercritical growth, and give upper bounds on the Hausdorff dimension of the singular sets for borderline solution. As a result, we can prove that the positive borderline solution must blow up in finite time. / Secondly, for the semilinear equations with critical growth, we apply a fundamental e-regularity property to illustrate the concentration phenomenon for the positive borderline solution when time goes to infinity. More precisely, we show that the lost energy can be counted exactly by the standard bubbles. / Du, Shizhong. / Adviser: Kai-Seng Chou. / Source: Dissertation Abstracts International, Volume: 70-09, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 113-119). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Shi-Zhong Du. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 56-58). / Chapter 1 --- Introduction --- p.5 / Chapter 2 --- A Nondegenerate Cahn-Hilliard Type Equation --- p.11 / Chapter 2.1 --- A priori estimation --- p.13 / Chapter 2.2 --- Long time existence --- p.19 / Chapter 3 --- The Thin Film Type Equation --- p.31 / Chapter 3.1 --- Positivity for n>4 --- p.31 / Chapter 3.2 --- Improved entropy estimates --- p.36 / Chapter 4 --- Finite Speed of Propagation --- p.43 / Chapter 4.1 --- Finite speed of propagation --- p.44 / Chapter 4.2 --- The regularity of free boundary --- p.54

Yao, Wei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 52-58). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Orbital stability without linear optical lattice --- p.12 / Chapter 2.1 --- Properties of single-spike bound states --- p.12 / Chapter 2.2 --- Proof of theorem 1.0.1 --- p.20 / Chapter 3 --- Orbital stability with linear optical lattice --- p.30 / Chapter 3.1 --- Properties of single-spike bound states --- p.30 / Chapter 3.2 --- Proof of theorem 1.0.2 --- p.33 / Chapter 3.3 --- Proof of theorem 1.0.3 --- p.34 / Chapter 3.4 --- Proof of theorem 1.0.4 --- p.37 / Chapter 4 --- Uniqueness for semilinear elliptic systems --- p.42 / Chapter 4.1 --- Proof of theorem 1.0.5 --- p.42 / Chapter 5 --- Appendix --- p.44 / Chapter 5.1 --- Appendix A --- p.44 / Chapter 5.2 --- Appendix B --- p.45 / Chapter 5.3 --- Appendix C --- p.47