The main idea of this thesis is to give an overview of the problems and difficulties that arise in solving optimal control problems with switching points. A brief discussion of existing optimality conditions is given and a numerical approach for solving the multipoint boundary value problems associated with the first-order necessary conditions of optimal control is presented. Two real-life aerospace optimization problems are treated explicitly. These are altitude maximization for a sounding rocket (Goddard Problem) in presence of a dynamic pressure limit, and range maximization for a supersonic aircraft flying in the vertical plane, also in presence of a dynamic pressure limit. In the second problem singular control appears along arcs with active dynamic pressure limit, which, in the context of optimal control, represents a first-order state inequality constraint. An extension of the Generalized Legendre-Clebsch Condition to the case of singular control along state/control constrained arcs is presented and is applied to the aircraft range maximization problem stated above. A contribution to the field of Jacobi Necessary Conditions is made by giving a new proof for the non-optimality of conjugate paths in the Accessory Minimum Problem. Because of its simple and explicit character the new proof may provide the basis for an extension of Jacobi’s Necessary Condition to the case of trajectories with interior point constraints. Finally, the result that touch points cannot occur for first-order state inequality constraints is extended to the case of vector valued control functions. / Ph. D.

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

by Kwok Siu Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 48-49). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background of switching networks --- p.1 / Chapter 1.2 --- Nonblocking properties of 3-stage networks --- p.5 / Chapter 1.3 --- Wide-sense nonblocking networks --- p.10 / Chapter 1.4 --- Routing algorithms by packing --- p.12 / Chapter 2 --- The Concept of the Upper Ideals --- p.15 / Chapter 3 --- "Routing algorithm over the network [6x10, 3x3, 10x6]" --- p.26 / Chapter 4 --- Simulation Program (SP) --- p.30 / Chapter 5 --- "Nonexistence of routing algorithm over the network [5x8, 3x3, 8x5]" --- p.35 / Chapter 6 --- Packing algorithms --- p.42 / Chapter 7 --- Summary and directions of further study --- p.47

Choy Man Ting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 66-69). / Abstracts in English and Chinese. / Acknowledgments --- p.ii / Abstract --- p.v / Table of Contents --- p.vii / List of figures --- p.viii / Chapter Chapter 1 --- p.12 / Chapter 1.1 --- OBS Network Architecture --- p.3 / Chapter 1.2 --- Offset Time and Reservation Schemes --- p.5 / Chapter 1.3 --- Research Objectives --- p.7 / Chapter 1.4 --- Overview --- p.8 / Chapter Chapter 2 --- p.9 / Chapter 2.1 --- WDM crossbar architectures --- p.9 / Chapter 2.2 --- Switch Based on Optical Crossbars --- p.10 / Chapter 2.3 --- Switch Based on Wavelength Grating Routers --- p.11 / Chapter Chapter 3 --- p.14 / Chapter 3.1 --- Basics of Dual Shuffle Exchange Network --- p.14 / Chapter 3.2 --- Dual Shuffle-exchange Network --- p.16 / Chapter 3.3 --- Proposed Architecture based on DSN --- p.19 / Chapter 3.4 --- Analysis on blocking due to output contention --- p.20 / Chapter 3.5 --- Implementation issues on the 4x4 switching module --- p.23 / Chapter 3.6 --- Analysis: Non-blocking versus banyan --- p.25 / Chapter Chapter 4 --- p.30 / Chapter 4.1 --- First Scheme --- p.30 / Chapter 4.2 --- Simulation on the first scheme --- p.33 / Chapter 4.3 --- Second Scheme: Tunable wavelength converter --- p.37 / Chapter 4.4 --- Third Scheme: Route to specific wavelength port --- p.42 / Chapter 4.5 --- Analysis on blocking due to insufficient stages --- p.46 / Chapter Chapter 5 --- p.49 / Chapter 5.1 --- Delay analysis of DSN --- p.49 / Chapter 5.2 --- Vertical Expansion --- p.51 / Chapter 5.3 --- Simulation results on vertical expansion --- p.52 / Chapter 5.4 --- Building DSN with 8x8 MEMS switches --- p.54 / Chapter 5.5 --- Prove of the proposed Quarter shuffle network --- p.56 / Chapter 5.6 --- Comparison between Quarter shuffle and doubled links approaches --- p.58 / Chapter Chapter 6 --- p.64 / Conclusion --- p.64 / Bibliography --- p.66

Michael J. Marcus. / 10255788 / Originally issued as an S.B. thesis, Dept. of Mechanical Engineering, Massachusetts Institute of Technology, 1972. / Includes bibliographical references (p. 53-54).

Issued also as a Ph.D. Thesis in the Dept. of Electrical Engineering, 1966. / Bibliography: p.56.

No description available.

Bibliography: p. 213-218. / Originally presented as the author's thesis, (Ph.D.) in the M.I.T. Dept. of Electrical Engineering and Computer Science, 1978. / Prepared under Advanced Research Projects Agency Contract ONR/N00014-75-C-1183.

Orientador: Jose Antenor Pomilio / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-13T08:24:07Z (GMT). No. of bitstreams: 1 Ortenzi_Gustavo_M.pdf: 4885292 bytes, checksum: 8a23d8845eaad19c72fe6f84e13af963 (MD5) Previous issue date: 2009 / Resumo: Descreve-se neste trabalho o desenvolvimento de uma fonte de alimentação chaveada para utilização em eletrodomésticos, capaz de entregar três saídas com níveis de tensão e potência diferentes, com uma mínima troca de componentes entre as três versões. Na primeira parte do trabalho é apresentada a aplicação da fonte e suas necessidades, seguido das especificações e da escolha da topologia e do modo de operação. Dando continuidade no desenvolvimento do projeto da fonte, apresenta-se a metodologia de cálculo adotada para o dimensionamento dos componentes a serem utilizados. Uma vez com os componentes dimensionados, apresenta-se a seleção dos componentes visando a estratégia de escalabilidade. Finalizando o dimensionamento dos componentes, apresenta-se o esquemático da fonte de alimentação e os componentes que são modificados de acordo com a versão em questão. A seguir, apresentam-se os resultados obtidos dos testes de regulação cruzada das saídas, as principais formas de onda de corrente e tensão do conversor, o rendimento das três versões considerando diferentes tensões de entrada de rede e a resposta a transiente. Fechando os resultados práticos, apresentam-se os ensaios de desenvolvimento de EMC/EMI, mostrando os resultados iniciais, as modificações implementadas e as soluções adotadas. No último capítulo apresenta-se as conclusões e as perspectivas de continuidade de desenvolvimento deste trabalho. / Abstract: This work describes the development of a switch mode power supply to be used at home appliances, capable to deliver three outputs with voltage and power different levels, changing a minimum number of components between them. At the first part of the work is presented the application of the power supply and its needs, followed by the specifications and choose of the topology and the operation mode. Continuing the design of the power supply's project, it is presented the methodology adopted to calculate and select the components to be used. With the components selected, it is presented the components selection criteria looking the scalability strategy. Ending the component's calculation and selection, the power supply schematic and the components that change according to the used version are shown. After the design, experimental results of the output cross regulation, main waveforms of voltage and current, efficiency and transient response of the three versions considering different AC Mains voltages are shown. Closing the experimental results, the EMI/EMC tests are presented, presenting the preliminary results, followed by the adopted modifications and solutions. The last chapter presents the conclusions and the perspectives of new developments of this work. / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

M.Ing. / This study considers improving the azimuth beam steering resolution of the circular Switched Parasitic Array (SPA) antennas (made up of dipoles) by a factor of two or more. In circular SPA antennas, beam steering is conventionally achieved by open-circuiting and shortcircuiting different parasitic elements and usually only one parasitic element is open-circuited at a time. However, such an approach results in low beam steering resolutions especially for the SPA antennas with few parasitic elements. In order to increase the azimuth beam steering resolution for the circular SPA antennas, two beam steering methods are proposed in this research work. In the first method, parasitic elements are open-circuited and short-circuited based on different combinations of the parasitic elements and the possible switch states. The proposed method was first validated by simulation tests using the MATLAB tool and WIPL-D. A prototype of the circular SPA antenna consisting of five elements was then implemented. It is noted that the simulation and measurement results match very well at 2.4 GHz. In order to have at least two combinations (from the first method) with almost similar gain and return loss, another simpler beam steering method was developed. The latter method is based on simultaneously open-circuiting either two or three neighbouring parasitic elements. The performance of the second method was studied through simulations using the circular SPA antenna geometries consisting of five, seven and nine elements. These geometries were first optimized (for gain and input impedance) and then modelled using WIPL-D. It was observed that the two methods double the azimuth beam steering resolution of the circular SPA antennas when compared to the conventional beam steering approaches of open-circuiting one parasitic element at a time. Variations in the structural parameters of the five elements circular SPA antenna at 2.4GHz were also investigated. In this procedure, the effects of variations (also considered as random errors) in the structural parameters (or antenna dimensions) on the performance of the SPA antennas were examined. Firstly, variations in each structural parameter were modelled with other structural parameters fixed as per specifications. Thereafter, effects of combined errors were also investigated. The simulation results demonstrated that variations in the structural parameter can either increase or decrease the gain and input impedance of the SPA antenna depending on the given specifications. The gain and input impedance sensitivities per variations in each structural parameter were computed to determine the degree at which the gain and input impedance can vary for a predefined change (error) in the structural parameter.