京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第18612号 / エネ博第308号 / 新制||エネ||63(附属図書館) / 31512 / 京都大学大学院エネルギー科学研究科エネルギー応用科学専攻 / (主査)教授 平藤 哲司, 教授 馬渕 守, 教授 土井 俊哉 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM

No description available.

Os algoritmos evolutivos são métodos heurísticos utilizados para a solução de problemas de otimização e que possuem mecanismos de busca inspirados nos conceitos da Teoria de Evolução das Espécies. Entre os algoritmos evolutivos mais populares, estão os Algoritmos Genéticos (GA) e a Programação Genética (GP). Essas duas técnicas possuem como ponto em comum o uso pesado do operador de recombinação, ou \"crossover\" - mecanismo pelo qual novas soluções são geradas a partir da combinação entre soluções existentes. O que as diferencia é a flexibilidade - enquanto que nos algoritmos genéticos as soluções são representadas por códigos binários, na programação genética essa representação é feita por algoritmos que podem assumir qualquer forma ou extensão. A preferência pelo operador de crossover não é simplesmente uma característica em comum das duas técnicas supracitadas, mas um poderoso diferencial. Na medida em que os indivíduos (as soluções) são selecionados de acordo com a respectiva qualidade, o uso do operador crossover tende a aumentar mais rapidamente a qualidade média da população se as partes boas de cada solução combinada (os \"building blocks\") forem preservadas. Holland [1975] prova matematicamente que sob determinadas condições esse efeito ocorrerá em algoritmos genéticos, em um resultado que ficou conhecido como \"Schema Theorem of GAs\". Entretanto, a implementação prática de GA (e, em especial, de GP) geralmente não ocorre segundo as condições supostas neste teorema. Diversos estudos têm mostrado que a extensão variável das estruturas utilizadas em GP dão um caráter de mutação ao operador de crossover, na medida em que a seleção aleatória dos pontos de combinação pode levar à destruição dos building blocks. Este trabalho propõe um novo operador de crossover, baseado em uma técnica de meta-controle que orienta a seleção dos pontos para a recombinação das soluções, respeitando o histórico de recombinação de cada ponto e a compatibilidade semântica entre as \"partes\" de cada solução que são \"trocadas\" neste processo. O método proposto é comparado ao crossover tradicional em um estudo empírico ligado à área Financeira, no qual o problema apresentado consiste em replicar a carteira de um fundo de investimentos setorial. Os resultados mostram que o método proposto possui performance claramente superior ao crossover tradicional, além de proporcionar a emergência de semântica entre as soluções ótimas. / Evolutionary algorithms are heuristic methods used to find solutions to optimization problems. These methods use stochastic search mechanisms inspired by Natural Selection Theory. Genetic Algorithms and Genetic Programming are two of the most popular evolutionary algorithms. These techniques make intensive use of crossover operators, a mechanism responsible for generating new individuals recombining parts of existing solutions. The choice of crossover operator to be used is very important for the algorithms´ performance. If individuals are selected according to the fitness, the use of crossover operator helps to quickly increase the average quality of the population. In GA we also observe the emergence of \"building blocks\", that is, encapsulated parts of good solutions that are often preserved during the recombination process. Holland [1975] proves that, under some conditions, this phenomenon will occur in GAs. This result is known as Schema Theorem of GAs. However, practical implementations of these algorithms may be far away from the conditions stated in Holland´s theorem. In these non-ideal conditions, several factor may contribute to higher rates of destructive crossover (building blocks destruction). This work proposes a new crossover operator, based on a meta-control technique that drives selection of crossover points according to recombination history and semantic compatibility between the code blocks to be switched. The proposed method is compared to common crossover in a case study concerning the replication of an investment fund. Our results show that the proposed method has better performance than the common crossover. Meta-control techniques also facilitate the emergence of building blocks that, in turn, give raise to emergent semantics that can be used to give meaning or interpretations to an optimal solution and its components.

Os algoritmos evolutivos são métodos heurísticos utilizados para a solução de problemas de otimização e que possuem mecanismos de busca inspirados nos conceitos da Teoria de Evolução das Espécies. Entre os algoritmos evolutivos mais populares, estão os Algoritmos Genéticos (GA) e a Programação Genética (GP). Essas duas técnicas possuem como ponto em comum o uso pesado do operador de recombinação, ou \"crossover\" - mecanismo pelo qual novas soluções são geradas a partir da combinação entre soluções existentes. O que as diferencia é a flexibilidade - enquanto que nos algoritmos genéticos as soluções são representadas por códigos binários, na programação genética essa representação é feita por algoritmos que podem assumir qualquer forma ou extensão. A preferência pelo operador de crossover não é simplesmente uma característica em comum das duas técnicas supracitadas, mas um poderoso diferencial. Na medida em que os indivíduos (as soluções) são selecionados de acordo com a respectiva qualidade, o uso do operador crossover tende a aumentar mais rapidamente a qualidade média da população se as partes boas de cada solução combinada (os \"building blocks\") forem preservadas. Holland [1975] prova matematicamente que sob determinadas condições esse efeito ocorrerá em algoritmos genéticos, em um resultado que ficou conhecido como \"Schema Theorem of GAs\". Entretanto, a implementação prática de GA (e, em especial, de GP) geralmente não ocorre segundo as condições supostas neste teorema. Diversos estudos têm mostrado que a extensão variável das estruturas utilizadas em GP dão um caráter de mutação ao operador de crossover, na medida em que a seleção aleatória dos pontos de combinação pode levar à destruição dos building blocks. Este trabalho propõe um novo operador de crossover, baseado em uma técnica de meta-controle que orienta a seleção dos pontos para a recombinação das soluções, respeitando o histórico de recombinação de cada ponto e a compatibilidade semântica entre as \"partes\" de cada solução que são \"trocadas\" neste processo. O método proposto é comparado ao crossover tradicional em um estudo empírico ligado à área Financeira, no qual o problema apresentado consiste em replicar a carteira de um fundo de investimentos setorial. Os resultados mostram que o método proposto possui performance claramente superior ao crossover tradicional, além de proporcionar a emergência de semântica entre as soluções ótimas. / Evolutionary algorithms are heuristic methods used to find solutions to optimization problems. These methods use stochastic search mechanisms inspired by Natural Selection Theory. Genetic Algorithms and Genetic Programming are two of the most popular evolutionary algorithms. These techniques make intensive use of crossover operators, a mechanism responsible for generating new individuals recombining parts of existing solutions. The choice of crossover operator to be used is very important for the algorithms´ performance. If individuals are selected according to the fitness, the use of crossover operator helps to quickly increase the average quality of the population. In GA we also observe the emergence of \"building blocks\", that is, encapsulated parts of good solutions that are often preserved during the recombination process. Holland [1975] proves that, under some conditions, this phenomenon will occur in GAs. This result is known as Schema Theorem of GAs. However, practical implementations of these algorithms may be far away from the conditions stated in Holland´s theorem. In these non-ideal conditions, several factor may contribute to higher rates of destructive crossover (building blocks destruction). This work proposes a new crossover operator, based on a meta-control technique that drives selection of crossover points according to recombination history and semantic compatibility between the code blocks to be switched. The proposed method is compared to common crossover in a case study concerning the replication of an investment fund. Our results show that the proposed method has better performance than the common crossover. Meta-control techniques also facilitate the emergence of building blocks that, in turn, give raise to emergent semantics that can be used to give meaning or interpretations to an optimal solution and its components.

Local search algorithms have been proved to be effective in refining solutions that have been found by other algorithms. Evolutionary algorithms, in particular global search algorithms, have shown to be successful in producing approximate solutions for optimisation and classification problems in acceptable computation times. A relatively new method, memetic algorithms, uses local search to refine the approximate solutions produced by global search algorithms. This thesis develops such a memetic algorithm. The global search algorithm used as part of the new memetic algorithm is a genetic program that implements the building block hypothesis by building simplistic decision trees representing valid solutions, and gradually increases the complexity of the trees. The specific building block hypothesis implementation is known as the building block approach to genetic programming, BGP. The effectiveness and efficiency of the new memetic algorithm, which combines the BGP algorithm with a local search algorithm, is demonstrated. / Dissertation (MSc)--University of Pretoria, 2006. / Computer Science / unrestricted

The key objective of this research is to develop a generic simulation modelling methodology that can be used to model stochastic continuous systems effectively. The generic methodology renders simulation models that exhibit the following characteristics: short development and maintenance times, user-friendliness, short simulation runtimes, compact size, robustness, accuracy and a single software application. The research was initiated by the shortcomings of a simulation modelling method that is detailed in a Magister dissertation. A system description of a continuous process plant (referred to as the Synthetic Fuel plant) is developed. The decision support role of simulation modelling is considered and the shortcomings of the original method are analysed. The key objective, importance and limitations of the research are also discussed. The characteristics of stochastic continuous systems are identified and a generic methodology that accommodates these characteristics is conceptualised and developed. It consists of the following eight methods and techniques: the variables technique, the iteration time interval evaluation method, the event-driven evaluation method, the Entity-represent-module method, the Fraction-comparison method, the iterative-loop technique, the time “bottleneck” identification technique and the production lost “bottleneck” identification technique. Five high-level simulation model building blocks are developed. The generic methodology is demonstrated and validated by the development and use of two simulation models. The five high-level building blocks are used to construct identical simulation models of the Synthetic Fuel plant in two different simulation software packages, namely: Arena and Simul8. An iteration time interval and minimum sufficient sample sizes are determined and the simulation models are verified, validated, enhanced and compared. The simulation models are used to evaluate two alternative scenarios. The results of the scenarios are compared and conclusions are presented. The factors that motivated the research, the process that was followed and the generic methodology are summarised. The original method and the generic methodology are compared and the strengths and weaknesses of the generic methodology are discussed. The contribution to knowledge is explained and future developments are proposed. The possible range of application and different usage perspectives are presented. To conclude, the lessons learnt and reinforced are considered. / Thesis (PhD (Industrial Engineering))--University of Pretoria, 2004. / Industrial and Systems Engineering / unrestricted

No description available.

The convergence of supramolecular and polymer sciences has led to the construction of analogs of traditional covalently-constructed polymeric structures and architectures by supramolecular methods. Host-guest complexations of polymers are also possible through well-defined synthesis of polymeric building blocks, for novel supramolecular polymers. Monotopic polymeric building blocks were synthesized by controlled radical polymerizations with a crown or paraquat initiator. The combinations of terminal and central functionalities of host and guest polymeric building blocks provided chain-extended and tri-armed homopolymers, and diblock and tri-armed copolymers. A supramolecular graft copolymer was formed from a main-chain poly(ester crown ether) and a paraquat terminated polystyrene. This comb-like copolymer was characterized by a large viscosity increase. A four-armed polystyrene-b-poly(n-butyl methacrylate) was synthesized from a pseudorotaxane macroinitiator derived from a complex of a crown-centered polystyrene and a dufunctional paraquat compound. A single peak with higher molecular weight from size exclusion chromatography proved the copolymer formation. Supramolecular interactions enhance the ionic conductivity of semi-crystalline ionic polymers; the ionic conductivity of a C₆-polyviologen and dibenzo-30-crown-10 mixture was 100 times higher than the polyviologen itself. However, ionic conductivities of amorphous polyviologens with polyethers were influenced only by glass transition temperature changes. New imidazolium ionic liquid monomers and imidazolium based polymers were synthesized for potential applications in electroactive devices, such as actuators. Structure-property relationships for pendant imidazolium polyacrylates and main-chain imidazolium polyesters were investigated. Terminal ethyleneoxy moeties enhanced ionic conduction 2~3 times; however, the alkyl chain length effect was negligible. For the imidazoium polyesters, higher ion conductivities result from 1) mono-imidazolium over bis-imidazolium, and 2) bis(trifluoromethanesulfonyl)imide polymers over hexafluorophosphate analogs. A semi-crystalline hexafluorophosphate polyester with C₁₀-sebacate-C₁₀, displayed 400-fold higher ionic conductivity than the amorphous C₆-sebacate-C₆ analogue, suggesting the formation of a biphasic morphology in the former polyester. New dicationic imidazolium salts have interesting features. 1,2-Bis[N-(N'-alkylimidazoilum)]ethane salts stack well in the solid state and possess multiple solid-solid phase transitions. They complex with dibenzo-24-crown-8 and a dibenzo-24-crown-8 based pyridyl cryptand with <i>K_a</i> = ~30 and 360 M¹, respectively. Some of these dicationic imidazolium salts have low entropies of fusion, typical of plastic crystals. These newly discovered imidazolium homopolymers have ionic conductivities up to 10⁴ (S cm⁻¹); however, better properties are still required. Well-designed block copolymers should provide both good electrical and mechanical properties from bicontinuous morphologies, such ion channels. / Ph. D.

In this dissertation, a design approach for medium voltage (MV) PCB-based components, such as the dc bus, is detailed. Key considerations, including electric field (E-field) grading near power terminals and PCB edges, cable feedthroughs, and the integration of components, are explored from the perspective of E-field management. A design example of a 3-level dc bus for a 6 kV-1 MW Power Electronics Building Block (PEBB) is presented. This PEBB was assembled using an array of low-voltage (LV) capacitors to create 3 kV PCB-based capacitor daughtercards, applying the same design principles as the dc bus. The scalability of this design approach is demonstrated with a 9-level dc bus rated for 24 kV. The insulation quality and MV performance of all PCBs have been assessed through partial discharge (PD) analysis using an Omicron MPD 600. The high-voltage (HV) design approach takes into account the mitigation of peak electric field intensity to minimize insulation degradation caused by electrical stress. In addition to electrical stress, the current carrying capacity (CCC) of these printed circuit boards (PCBs) was assessed concerning steady-state thermal performance and short-circuit (SC) robustness. Multiple configurations were examined to determine the current density, with the aim of reducing temperature. The insulation performance following repetitive fault events was monitored. Although the Partial Discharge Inception Voltage (PDIV) reduced by 50% after 140 SC faults, it remained higher than the operational voltage. This demonstrates the feasibility of utilizing HV PCBs in practical applications. Finally, the insulation performance of a complete 6 kV PEBB assembly was assessed. The PEBB was assembled component by component, with a focus on tracking the PDIV at each stage. This approach allowed for the qualification of the PEBB for use in a 24 kV PEBB-based converter with a common mode (CM) PDIV of 33.2 kV. Subsequently, multiple PEBBs underwent testing to simulate their operation within a 24 kV converter configuration, ensuring dependable performance when assembled. Custom support structures were also designed and tested to accommodate the 24 kV PCB bus and dc-link capacitors, serving as interconnections between multiple phase legs and the external voltage source. / Doctor of Philosophy / Power electronic converters are used in many applications ranging from low power to high. Some applications include cellphone chargers, electric vehicle chargers, and even power distribution systems on land and sea. The electronics devices that are at the heart of these converters are rapidly advancing. Newer devices are being fabricated using so-called wide bandgap (WBG) materials such as silicon carbide as opposed to their older silicon counterparts. These WBG devices allow power converters to shrink in size due to their enhanced performance. As these device technologies evolve, the need to completely redesign systems to fully leverage their benefit arise. In this dissertation, the work centers around computer based simulations, coupled with hardware experiments, to design custom components that will allow engineers to significantly reduce the size and weight of medium voltage (MV) power electronic converters while also increasing their power. The printed circuit board (PCB) is a standard component used in every day electronics. They are used to host electronic components while creating precise electrical connections between them. Although these are very useful in circuits operating at lower voltages, their use has not been widely explored for applications requiring higher voltage such those as where these advancing WBG devices would provide the most benefit. A design method is introduced which allows these boards to be used at relatively high voltage (HV). The robustness of these HV PCBs were evaluated to ensure the feasibility of their continued use after multiple fault events. The size of power converter can be largely affected by the cooling system. Although the WBG devices can withstand higher temperature operation, the temperature of the device can still be a limiting factor. It is preferred to extract heat from the devices, allowing them to process more power. A standard component of cooling systems using forced air is the heatsink. The standard heatsink has corners that create sharp corners which are not ideal in high voltage systems; spacing between components must be increases to mitigate the effects caused by these sharp corners. Computer simulations were used to aid in the design of a heatsink profile which eliminates these sharp corners and was shown to reduce the clearance between cooling system components by up to 50%. Each component was individually designed and tested to ensure its reliable operation. However, it's crucial to verify their performance when assembled with other components. In addition to designing components for high voltage operation, the insulation system for a complete converter assembly was evaluated. Once a full converter was successfully qualified, a similar approach was taken to evaluate multiple converters when assembled together, much like building blocks, to construct even larger converters. This rigorous testing and assembly process ensures the reliable operation of the entire system.

IFRS 的準則，對於未來想國際化的國內保險公司及面對國際投資人，是使用相同一套會計準則，不需再調整財報，有助提升國際競爭力及國際形象，若海外發行有價證券也不需再重編財報，可節省籌資成本。依目前國際發展情勢，IFRS 4 已廣泛為全球保險市場之採用準則，直接採用(adoption)IFRS 4 亦成為國際保險市場之趨勢，我國亦於2011 年1 月1 日公佈IFRS 4 第一階段生效，期與世界接軌，IFRS 4 未來對我國保險業將會有更重大之影響。為未雨綢繆，遂引起本文對此議題研究之動機。壽險業為長年期保險合約，須採用要素衡量法評估。為符合IFRS 4 第二階段規定之要素衡量法及保費分配法之評估，採個案產險公司為研究對象，祈予在IFRS 4 第二階段實施前，台灣產險業能提早做準備，並以充足時間瞭解並完善規劃準備執行配合，以符合未來主管機關之相關規定。 本論文以個案公司為例，評估國際財務報導準則第四號對保險公司精算規範與目前保險局規範保險公司相關精算試算之差異，特選用一般自用汽車財產損失險及傷害險採用保費分配法，工程險採用要素衡量法試算，並分析差異之內容，以了解個案公司未來因IFRS4 實施對該公司財務之影響。 以目前資料推估實施當年採用保費分配法會對盈餘報導較為有利，採用要素衡量法當年度會有對盈餘報導不利的衝擊，整體而言，對個案公司未來營運應無重大影響。 / The principles of IFRS ,which is using the same set of accounting standards, is conducive to enhance the international competitiveness and image for domestic insurance companies who scheme to internationalization and contact with international investors. In addition, companies can also saving the cost of issuance of foreign securities since they do not need to restate the financial statements. Taiwan also announced the IFRS 4 phase I be effective in January 1, 2011, hoping to connect with the world. In the future, IFRS 4 will have a more significant influence on Taiwan's Insurance Industry. In order to thinking ahead, which bring in my motivation to researching on this topic. Life insurance industry is major in long term insurance contracts, has to use the Building Block Approach. To comply the IFRS 4 Phase II which using the Building Block Approach and Premium Allocation Approach, I adopt the case of property Insurance as the research objectives. In order to fit with the relevant provisions of the competent authority in the future, Expecting Taiwan’s property Insurance can prepare in advance, well understanding and scheduling, before the implement of IFRS 4 phase II. In this paper, which use the property insurance case, evaluation the actuarial valuation difference of IFRS 4 and relevant norms of Insurance Bureau. I use Premium Allocation Approach to value the usually own car property damage insurance and casualty Insurance, and use Building Block Approach to evaluate Engineering Insurance. Through analysis of the content, to understanding the influence of IFRS 4 for the study company in the future. Based on the current data, adopting Building Block Approach is beneficial for the study company. Comparatively, Premium Allocation Approach is disadvantage for the study company. In conclusion, the implement of IFRS 4 should have no significant influence to the study company in the future.