Considering the South China Sea dispute as a flashpoint of regional stability and power balance within the Southeast Asian region, the first failure in ASEAN history to reach a consensus in 2012 and the deadlock in 2016 on this issue brought up uncertainty towards the ability of ASEAN member states to reach a consensus on the South China Sea issue. This thesis seeks to analyze this issue based on neo-classical realism and the two-level games theory to what extent, if any, do the ASEAN member states’ domestic factors and external relations influence their decision towards the South China Sea dispute. The theoretical framework of neoclassical realism provides three indicators for analysis, which are national interests, domestic politics, and the role and perception of political leaders. The two-level games theory addresses on the preferences and coalitions within states, political institutions, and the role of chief negotiators as the three indicators to determine the win-sets of the ASEAN member states. The conclusions show the different win-sets size of ASEAN member states vary accordingly from a larger win-sets size of an authoritarian state to a smaller win-sets size of a more democratic state.

Electrical vehicles have become more popular during recent years due to their reduced greenhouse gas emissions. The research within Li-ion batteries is therefore moving fast. Presently, two-level converters transforming the current from DC to AC. However, an alternative method of power conversion is by utilizing modular multilevel converters, which can perform better harmonics than the two-level converter. This study aims to research the impact of these converters on battery cell heat generation. In doing so, developing a digital twin of the Li-ion battery cell, which in this case is a Samsung 28 Ah nickel, manganese, and cobalt prismatic battery cell, focusing on the thermal aspects such as heat generation, heat capacity, and thermal conductivity. The modular multilevel converter may also cause significant overtones, harmonics. Therefore, this study investigates the thermal impact of these frequencies. The results show that it is possible to, via experiments and simulations, determine the heat capacity and thermal conductivity of a Li-ion cell. Furthermore, the frequencies caused by the modular multilevel converter cause a temperature rise in the cell, compared to the two-level converter. Although, if the same root mean square for the modular multilevel converter current is used, the temperature rise is lower compared to DC. During the load cycles, the results show that there are slightly higher temperatures at the positive current collector side compared to the negative. It is, however, the jelly roll core that has the highest temperatures.

This thesis addresses the military capabilities gap between the US and European member states of NATO. It seeks to answer the question, why does the US-European capabilities gap persist despite apparent agreement between Allies on strategic capabilities objectives and cooperative solutions? The paper first establishes the need for a strong, independent European Security and Defense Identity within the Alliance, particularly since NATO's operations in Libya. It then defines and explicates the military capabilities gap within the Alliance, including its scope, history, and attempts to find cooperative solutions. This analysis demonstrates that there is broad agreement both on what the Alliance requires for military capabilities and for how best to obtain them (cooperatively), yet the gap has persisted and grown for two decades. In an attempt to solve this empirical puzzle, the paper employs a two-level games framework to analyze the NATO defense planning process, which links supranational capabilities planning for the Alliance to national-level execution, dependent upon funding from state parliaments. Faced with the general answer that fiscal constraints preclude states from following through on their commitments, the paper delves deeper to determine factors that may influence differences in defense...

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Reduced-order models are frequently used in the simulation of complex flows to overcome the high computational cost of direct numerical simulations, especially for three-dimensional nonlinear problems. Proper orthogonal decomposition, as one of the most commonly used tools to generate reduced-order models, has been utilized in many engineering and scientific applications. Its original promise of computationally efficient, yet accurate approximation of coherent structures in high Reynolds number turbulent flows, however, still remains to be fulfilled. To balance the low computational cost required by reduced-order modeling and the complexity of the targeted flows, appropriate closure modeling strategies need to be employed. In this dissertation, we put forth two new closure models for the proper orthogonal decomposition reduced-order modeling of structurally dominated turbulent flows: the dynamic subgrid-scale model and the variational multiscale model. These models, which are considered state-of-the-art in large eddy simulation, are carefully derived and numerically investigated. Since modern closure models for turbulent flows generally have non-polynomial nonlinearities, their efficient numerical discretization within a proper orthogonal decomposition framework is challenging. This dissertation proposes a two-level method for an efficient and accurate numerical discretization of general nonlinear proper orthogonal decomposition closure models. This method computes the nonlinear terms of the reduced-order model on a coarse mesh. Compared with a brute force computational approach in which the nonlinear terms are evaluated on the fine mesh at each time step, the two-level method attains the same level of accuracy while dramatically reducing the computational cost. We numerically illustrate these improvements in the two-level method by using it in three settings: the one-dimensional Burgers equation with a small diffusion parameter, a two-dimensional flow past a cylinder at Reynolds number Re = 200, and a three-dimensional flow past a cylinder at Reynolds number Re = 1000. With the help of the two-level algorithm, the new nonlinear proper orthogonal decomposition closure models (i.e., the dynamic subgrid-scale model and the variational multiscale model), together with the mixing length and the Smagorinsky closure models, are tested in the numerical simulation of a three-dimensional turbulent flow past a cylinder at Re = 1000. Five criteria are used to judge the performance of the proper orthogonal decomposition reduced-order models: the kinetic energy spectrum, the mean velocity, the Reynolds stresses, the root mean square values of the velocity fluctuations, and the time evolution of the proper orthogonal decomposition basis coefficients. All the numerical results are benchmarked against a direct numerical simulation. Based on these numerical results, we conclude that the dynamic subgrid-scale and the variational multiscale models are the most accurate. We present a rigorous numerical analysis for the discretization of the new models. As a first step, we derive an error estimate for the time discretization of the Smagorinsky proper orthogonal decomposition reduced-order model for the Burgers equation with a small diffusion parameter. The theoretical analysis is numerically verified by two tests on problems displaying shock-like phenomena. We then present a thorough numerical analysis for the finite element discretization of the variational multiscale proper orthogonal decomposition reduced-order model for convection-dominated convection-diffusion-reaction equations. Numerical tests show the increased numerical accuracy over the standard reduced-order model and illustrate the theoretical convergence rates. We also discuss the use of the new reduced-order models in realistic applications such as airflow simulation in energy efficient building design and control problems as well as numerical simulation of large-scale ocean motions in climate modeling. Several research directions that we plan to pursue in the future are outlined. / Ph. D.

This thesis provides a detailed explanation of the complex interrelations between national political dynamics and policy-making processes within the European Union, with a particular emphasis on Germany's involvement in the negotiation of the Corporate Sustainability Due Diligence Directive. The central research question is as follows: What factors influenced Germany's decision to block the CSDD adoption despite agreeing to the proposal just a month earlier? The theoretical approach for this research integrates normative institutionalism and a new model of foreign policy analysis within the framework of two-level game theory. These theoretical constructs are leveraged to dissect the dual-level negotiation processes, facilitating an analysis of how Germany navigates between internal pressures and broader EU policy mandates. This theoretical exploration extends to assess the overarching dynamics of EU legislative processes, especially in relation to the alignment and conflict between economic imperatives and normative policy objectives such as sustainability. Methodologically, this thesis utilises in-depth theory- building process-tracing to identify causal-mechanisms that led from the proposal of the CSDD draft to Germanys decision to hinder the adoption of the agreed upon draft. The results underscore a nuanced landscape of negotiation and adjustment, wherein Germany's economic imperatives frequently conflict with the EU's sustainability ambitions. The analysis demonstrates that Germany's external commitments to EU sustainability policies are significantly conditioned by domestic economic considerations, which in turn influence Germany's tactical approaches within EU policy negotiations.

Un préconditionneur à deux niveaux, reposant sur la technique d’accélération d’Aitken d’une suite de q vecteurs solutions de l’interface d’un pro- cessus itératif de Schwarz Additif Restreint, est conçu. Cette nouvelle technique, dénomée ARAS(q), utilise une approximation grossière de la solution sur l’interface. Différentes méthodes sont proposées, aboutissant au développement d’une tech- nique d’approximation par Décomposition en Valeures Singulières de la suite de vecteurs. Des implémentations parallèles des méthodes d’Aitken-Schwarz sont pro- posées et l’étude conduit à l’implémentation d’un code totalement algébrique, sur un ou deux niveaux de parallélisation MPI, écrit dans l’environnement de la biblio- thèque PETSc. Cette implémentation pleinement parallèle et algébrique procure un outil flexible pour la résolution de systèmes linéaires tels que ceux issus de la dif- férentiation automatique des solutions de Navier-Stokes dépendant des paramètres de la simulation / A two level preconditioner, based on the Aitken acceleration technique of a sequence of q interface’s solution vectors of the Restricted Additive Schwarz iterative process, is designed. This new technique, called ARAS(q), uses a coarse approximation of the solution on the interface. Different methods are discussed, leading to the development of an approximation technique by Singular Value De- composition of the sequence of vectors. Parallel implementations of Aitken-Schwarz methods are proposed, and the study leads to a fully algebraic one-level and two- level MPI implementation of ARAS(q) written into the PETSc library framework. This fully parallel and algebraic code gives an adaptive tool to solve linear systems such as those arising from automatic differentiation of compressible Navier-Stokes solution with respect to the simulation’s parameters

本論文的研究動機始於有感民族陣線在當今法國政壇的影響力不容小覷，「勒班效應」也使得1980年代中期後極右主義的風潮在西歐蔓延開來，因此吾人在研究歐洲整合的過程時，似應考慮到會員國國內這些反歐洲化的政治現象的發展。然而，主流的國際關係理論認為國際體系構成單位的層次分析並不重要。雖然國際關係體系論的建立被視為是本學門邁向「科學化」的重要嘗試，惟其亦使得學者在研究區域整合時面臨了見林不見樹的困境，本文的研究目的也就在試圖證明會員國國內政治不能被歐洲整合研究所忽視。 本論文以法國極右主義與歐盟移民政策之關聯為例，透過二重賽局的分析架構進行實證研究，研究結果顯示法國右派政府為了爭取極右派選民的票源而吸納民族陣線的反移民訴求，不僅反映在該國自1980年代中期以降的移民政策對非歐盟國家移民的趨於排斥，亦顯現於法國政府在歐盟移民政策共同體化之前與其他會員國協調移民政策時的保守立場。本研究指出，法國極右派在國內層次的影響能夠經由政府的利益匯集過程而到達歐盟層次，從而說明學者不宜貿然分割國內與國際政治研究。另一方面，案例亦顯示政府領袖的偏好在形成後仍有可能發生轉變，因此做為跨層次分析工具的二重賽局尚有修正其架構的必要性，如何發展有效連結國內政治與國際關係的理論途徑與分析架構，對於區域研究學者實屬緊要。

國際貿易會決定國內不同行為者的利益分配，促使國內產生主張自由貿易與支持保護主義的陣營，進而影響貿易政策的制訂。本論文以紡織品貿易為主題，首先闡述保護主義為何在貿易自由化浪潮中，依舊能夠貫穿20世紀後半葉的紡織品貿易，卻又在1990年代末期開始式微；其次，本論文分析當全球紡織品貿易於2005年全面取消配額之後，中國紡織品的大量出口，如何引發進口國內部保護主義勢力的反撲，令歐盟和美國先後和中國重新展開紡織品配額談判。最後，本論文分析歐、美境內自由貿易與保護主義兩個陣營，如何影響和中國的談判結果，並藉此比較具有不同制度的經濟體，如何回應國際經濟秩序的變化。 本文援引Robert Putnam所提出的「雙層賽局」分析架構，並進一步討論國內制度如何國際談判產生影響。經研究後發現，歐盟和美國內部的政治聯盟是影響談判結果的重要因素。這兩起談判雖然都源於本國紡織業者在受到中國紡織品的強力挑戰之後，進而要求政府必須出面解決這個問題，但是，由於歐盟和美國內部政治制度設計的不同，讓不同陣營有不同的施力空間，最後使得兩起談判結果有所差異。在歐盟方面，紡織產業和進口商之間的衝突，透過歐盟尊重多元的政治制度設計而有了旗鼓相當的局勢，因此歐盟執委會出面和中國談判之前，必須兼顧這兩個陣營的利益，令歐盟和中國的談判結果較有利於中國紡織品出口。但是在美國方面，儘管進口商和紡織業者之間的利益也是有所衝突，不過紡織業者最後透過政治運作而佔了上風，加上美國政府也希望藉由限制中國紡織品來降低對中國的貿易逆差，使得中美談判的結果對中國較為嚴格，具有濃厚的保護主義色彩。 / International trade distributes various interests to actors, who then form two camps supporting free trade and protectionism, respectively. Both two camps also influence the decision-making of trade policy. This thesis focuses on textile trade and analyzes why protectionism could prevail in the textile trade during the second half of 20th century, and why it declined in the end of 1990s. Second, this thesis analyzes how China’s considerable textile exports after 2005 incur resistances of protectionists in the European Union (EU) and the United States (US). Those protectionists request their government to negotiate with China on textile products. However, those requests attract the counterpunches from supporters of free trade. By rendering the “Two-level Game Theory”, this thesis discovers that the domestic coalitions in the EU and the US significantly determine the results of negotiations. Although both negotiations result from powerful challenges of Chinese textile products, the EU and the US have their own institutional designs and then take different responses. In the EU, conflicts between textile industry and textile importers are of approximately equal strength. The European Commission has to hold an eclectic position between the supporters of free trade and protectionists. As a result, the results of EU-Sino negotiation favor China’s textile export to the European market. On the other hand, even though there are conflicts between textile producers and importers, producers get the upper hand by lobbying politicians. In addition, because the US government also intends to reduce the US’ tremendous trade deficit with China by limiting China’s textile product, the US-Sino textile quota negotiation is much more protectionism-oriented.