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Srikanthan, Sasiharan Sudeshna. "An investigation of matrix switching topologies and algorithms." Thesis, University of Hertfordshire, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315633.
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Gilorma, Mike. "Path Panels vs. Digital Switching Matrices." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595788.
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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada<br>Patch panels are still frequently used in telemetry installations as a means for routing signals during and in between missions. These patch panels have been used for decades and have many benefits operationally speaking. Digital switching matrices on the other hand, while very popular in the broadcasting and music industries, are not being fully utilized in the telemetry world. Digital switches offer many of the same benefits of patch panels along with an abundance of added features including signal conversion and distribution. This paper describes the benefits of migrating from patch panels to digital switching matrices. It will discuss both the pros and cons of each technology as well as look at the short term and long term cost implications of each. This paper will also discuss return on investment and operational improvements that can be gained from utilizing digital switching matrices in place of patch panels.
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Jaques, Stuart Roland. "A TLM analysis of an all-optical switching device." Thesis, University of Hull, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363266.
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Bland, Michael. "An investigation of matrix converter losses and soft switching techniques." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289478.
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Current research and the price of semiconductors are making Matrix Converter topologies more attractive and practically viable for many applications. One of the key benefits claimed for the matrix approach is the possibility of greater power density due to the absence of a DC link. To capitalise on this it is necessary to make the input filter small by having a sufficiently high switching frequency. In order to arrive at optimised solutions in terms of filtering, heatsinking and packaging, it is important to have accurate models to predict power circuit losses as a function of operating point and switching frequency. This aim of this thesis is to further the understanding of Matrix Converter current commutation with a focus on switching losses. The commutation process is analysed in detail and a complete loss model for Matrix Converter circuits is developed. The use of circuit simulation software in the prediction of switching losses is investigated and comparisons are made with experimentally measured results. The loss model is used to compare Matrix Converter losses with a functionally equivalent sinusoidal front end inverter. A review of soft switching techniques for Matrix Converter circuits is given. A new auxiliary resonant soft switching Matrix Converter is presented which overcomes many of the problems of the previously proposed circuits. The design, construction and testing of a 6kW prototype soft switching Matrix Converter is presented to evaluate the feasibility of the topology.
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Iqbal, Javed. "Application of regime switching and random matrix theory for portfolio optimization." Thesis, University of Essex, 2018. http://repository.essex.ac.uk/22633/.
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Market economies have been characterized by boom and bust cycles. Since the seminal work of Hamilton (1989), these large scale fluctuations have been referred to as regime switches. Ang and Bekaert (2002) were the first to consider the role of regime switches for stock market returns and portfolio optimisation. The key stylized facts regarding regime switching for stock index returns is that boom periods with positive mean stock returns are associated with low volatility, while bear markets with negative mean returns have high volatility. The correlation of asset returns also show asymmetry with greater correlation being found during stock market downturns. In view of the large portfolio losses from correlated negative movements in asset returns during the recent 2007 financial crisis, it has become imperative to incorporate regime sensitivity in portfolio management. This thesis forms an extensive application of regime sensitive statistics for stock returns in the management of equity portfolios for different markets. Starting with the application to a small 3 asset portfolio for UK stocks (in Chapter 4), the methodology is extended to large scale portfolio for the FTSE-100. In chapters 5 and 6, respectively, using stock index data from the subcontinent (India, Pakistan and Bangladesh) and for the Asia Pacific, optimal regime sensitive portfolios have been analysed with the MSCI AC Index (for Emerging and Asia Pacific Markets) being taken as the benchmark index. Portfolio performance has been studied using a dynamic end of month rebalancing of the portfolio on the basis of regime indicators given by market index and relevant regime dependent portfolio statistics. The cumulative end of period returns and risk adjusted Sharpe Ratio from this exercise is compared to the simple Markowitz mean-variance portfolio and market value portfolio. The regime switching optimal portfolio strategy has been found to dominate non-regime sensitive portfolio strategies in Asia Pacific and 3 asset portfolio for UK stocks cases but not in Subcontinent case (for the first half of out-sample period). In the case of the relationship of the sub-continental indexes vis-à-vis the MSCI benchmark index, the latter has negligible explanatory power for the former especially for the first half of out-sample period. Hence, the regime indicators based on MSCI emerging market index have detrimental effects on portfolio selection based on the sub-continental indexes. As regime sensitive variance–covariance matrices have implications for the selection of optimal portfolio weights, the final Chapter 7 uses the FTSE-100 and its constituent company data to compare and contrast the implications for optimal portfolio management of filtering the covariance matrix using Random Matrix Theory (RMT). While it is found that filtering the variance-covariance matrix using Marchenko-Pasteur bounds of RMT improves optimal portfolio choice in both non-regime and regime dependent cases, remarkably in the latter case for Regime 2 determined variance-covariance matrix, the RMT filter was least needed. This result is given in Chapter 7, Table 7.5-1. This confirms the significance of using Hamilton (1989) regime sensitive statistics for stock returns in identifying the ‘true’ non-noisy variance-covariance relationships. The RMT methodology is also useful for identifying the centrality, based on eigenvector analysis, of the constituent stocks in their role in driving crisis and non-crisis market conditions. A fully automated suite of programs in MATLAB have been developed for regime switching portfolio optimization with RMT filtering of the variance-covariance matrix.
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Chia, Liang. "Language shift in a Singaporean Chinese family and the matrix language frame model." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365765.
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Kabasele, Philothe Mwamba. "TESTING THE MATRIX LANGUAGE FRAME MODEL WITH EVIDENCE FROM FRENCH-LINGALA CODE-SWITCHING." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/616.
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My thesis investigates the universality of the Matrix Language Frame model developed by Myers-Scotton (2002). The work tests the model by using bilingual data which display code-switching between French and the low variety of Lingala. The main concern of the work is to test the constraints that are posited in terms of principles of the model and which claim that the Matrix Language dictates the morphosyntactic frame of a bilingual Complementizer Phrase (CP). In the light of the findings of this study, it was shown that the ML model failed to account for a number of situations; and such was the case of the Morpheme Order Principle and double morphology, specifically with the outsider late system morphemes.
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Komolafe, Olufemi O. "High-speed optical packet switching over arbitrary physical topologies using the Manhattan Street Network." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366847.
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Cha, Han Ju. "Analysis and design of matrix converters for adjustable speed drives and distributed power sources." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/1048.
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Recently, matrix converter has received considerable interest as a viable alternative to the conventional back-to-back PWM (Pulse Width Modulation) converter in the ac/ac conversion. This direct ac/ac converter provides some attractive characteristics such as: inherent four-quadrant operation; absence of bulky dc-link electrolytic capacitors; clean input power characteristics and increased power density. However, industrial application of the converter is still limited because of some practical issues such as common mode voltage effects, high susceptibility to input power disturbances and low voltage transfer ratio. This dissertation proposes several new matrix converter topologies together with control strategies to provide a solution about the above issues.
In this dissertation, a new modulation method which reduces the common mode voltage at the matrix converter is first proposed. The new method utilizes the proper zero vector selection and placement within a sampling period and results in the reduction of the common mode voltage, square rms of ripple components of input current and switching losses.
Due to the absence of a dc-link, matrix converter powered ac drivers suffer from input voltage disturbances. This dissertation proposes a new ride-through approach to improve robustness for input voltage disturbances. The conventional matrix converter is modified with the addition of ride-through module and the add-on module provides ride-through capability for matrix converter fed adjustable speed drivers.
In order to increase the inherent low voltage transfer ratio of the matrix converter, a new three-phase high-frequency link matrix converter is proposed, where a dual bridge matrix converter is modified by adding a high-frequency transformer into dc-link. The new converter provides flexible voltage transfer ratio and galvanic isolation between input and output ac sources.
Finally, the matrix converter concept is extended to dc/ac conversion from ac/ac conversion. The new dc/ac direct converter consists of soft switching full bridge dc/dc converter and three phase voltage source inverter without dc link capacitors. Both converters are synchronized for zero current/voltage switching and result in higher efficiency and lower EMI (Electro Magnetic Interference) throughout the whole load range. Analysis, design example and experimental results are detailed for each proposed topology.
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Backlund, Alexander. "Switching hybrid recommender system to aid the knowledge seekers." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414623.
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In our daily life, time is of the essence. People do not have time to browse through hundreds of thousands of digital items every day to find the right item for them. This is where a recommendation system shines. Tigerhall is a company that distributes podcasts, ebooks and events to subscribers. They are expanding their digital content warehouse which leads to more data for the users to filter. To make it easier for users to find the right podcast or the most exciting e-book or event, a recommendation system has been implemented. A recommender system can be implemented in many different ways. There are content-based filtering methods that can be used that focus on information about the items and try to find relevant items based on that. Another alternative is to use collaboration filtering methods that use information about what the consumer has previously consumed in correlation with what other users have consumed to find relevant items. In this project, a hybrid recommender system that uses a k-nearest neighbors algorithm alongside a matrix factorization algorithm has been implemented. The k-nearest neighbors algorithm performed well despite the sparse data while the matrix factorization algorithm performs worse. The matrix factorization algorithm performed well when the user has consumed plenty of items.
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Semethe, Mpho Maboitumelo. "Code-switching, Structural change and Convergence: A study of Sesotho in contact with English in Lesotho." Master's thesis, Faculty of Humanities, 2019. http://hdl.handle.net/11427/31233.
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This study investigates whether code-switching practices among Sesotho-English bilinguals promote convergence between Sesotho and English. First, the study identifies different types and patterns of code-switching between Sesotho and English and analyses them using Myers-Scotton’s (1993) Matrix Language Frame model and Myers-Scotton and Jake’s (2000) 4-M model. Second, it applies the ML turnover in order to detect convergence in Sesotho-English code-switching data and to observe which direction it takes. The study also explores other factors contributing to change in the structure of Sesotho, which are not necessarily influenced by convergence. In conducting this study, data was collected through interviews that were held with younger bilingual speakers from different tertiary institutions in and around Maseru (Lesotho) and through recorded youth-centred phone-in radio programmes. Findings from the analysis of data reveal simple to complex Sesotho-English code-switching performance of various types and strategies. Findings also show through the existence of composite language in Sesotho-English code-switching that there is a turnover in the ML, which indicates a development of an asymmetrical convergence between Sesotho and English. It was also discovered that, although other changes in the Sesotho structure are not English influenced, they are enhanced mostly by younger urban bilingual speakers’ frequent “looser” approach to Sesotho. This is an indication that Sesotho’s susceptibility to change correlates strongly with age; that is, both the length of time contact between Sesotho and English has existed, and the generation in which change is mostly found. This thesis adds and documents a different perspective to the previously recorded changes on Sesotho-English contact in Lesotho.
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Andersson, Peter. "Charge Transport Modulation and Optical Absorption Switching in Organic Electronic Devices." Doctoral thesis, Norrköping : Department of Science and Technology, Linköping University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10271.
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Balakrishnan, Anand Kumar. "Soft switched high frequency ac-link converter." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3156.
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Li, Quan, and q. li@cqu edu au. "DEVELOPMENT OF HIGH FREQUENCY POWER CONVERSION TECHNOLOGIES FOR GRID INTERACTIVE PV SYSTEMS." Central Queensland University. School of Advanced Technologies & Processes, 2002. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20020807.152750.
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This thesis examines the development of DC-DC converters that are suitable for Module Integrated Converters, (MICs), in grid interactive photovoltaic (PV) systems, and especially concentrates on the study of the half bridge dual converter, which was previously developed from the conventional half bridge converter. Both hard-switched and soft-switched half bridge dual converters are constructed,
which are rated at 88W each and transform a nominal 17.6Vdc input to an output in the range from 340V to 360Vdc. An initial prototype converter operated at 100kHz and is used as a base line device to establish the operational behaviours of the converter. The second hard-switched converter operated at 250kHz and included a coaxial matrix transformer that significantly reduced the power losses related to the transformer leakage inductance. The soft-switched converter operated at 1MHz and is capable of absorbing the parasitic elements into the resonant tank. Extensive theoretical analysis, simulation and experimental results are provided for each converter. All three converters
achieved conversion efficiencies around 90%. The progressive increases in the operation frequency, while maintaining the conversion efficiency, will translate into the reduced converter size and weight. Finally different operation modes for the
soft-switched converter are established and the techniques for predicting the occurrence of those modes are developed. The analysis of the effects of the transformer winding capacitance also shows that soft switching condition applies for both the primary side mosfets and the output rectifier diodes.
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Wang, Erik. "Growing as a business in a mature business-to-business service industry : A case study in the Swedish energy services industry." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-249671.
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In the past decade, the energy markets within the European Union haveincreasingly been deregulated as a means to promote increased competition, andthereby efficiency, on these markets. As a result of this, several energy institutionshave been forced to become unbundled from their parent companies and toinstead form smaller separate entities. Contracts that previously were guaranteedare now subjected to public competition and in order to not risk decreasing in size,these companies must now find new ways to grow and generate new business. To study this, a case study was conducted at a Swedish energy servicescompany who recently has been unbundled from one of the largest Swedish gridowners. Specifically, the research focused on what companies in maturebusiness-to-business services contexts can do to increase their sales. The studywas conducted primarily through gathering qualitative interview data bothinternally and externally, but secondary data from surveys were also used. The findings indicate that the case company should focus on pursuing a combinedstrategy of market penetration and service/product penetration to increase sales.In addition, the company should continue to invest substantially into relationshipmarketing practices in order to build long-term potential for growth. Specifically,the findings indicate it should improve its communication and relationshipinvestment towards its customers. Furthermore, it should adopt appropriatestrategies to reduce the switching barriers of its prospective customers. The findings contribute to the understanding of how companies in similarsituations as the case company can act in order to drive growth. The studyprovides further empirical data in a field that has received relatively little academicattention. The author also suggests venues for future research in the concludingchapters.
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Hladký, Pavel. "Numerická klávesnice." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413032.
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This thesis deals with design of numeric keyboard, which can be connected to personal computer or laptop through USB interface. This numeric keyboard can be also configured using application for operating system Windows. Backlight pattern generator is also part of this application. Theoretic part deals with various types of keyboards, switches and closer description of USB interface. Practical part deals with sole design of circuit that detects keystrokes and sends information about active switches through USB, description of used components, description of microcontroller service routine and description of the application for backlight pattern generating. At the end of this thesis are described results of measurements which were made to choose mechanical switches with shortest debounce time and keyboard response to key press.
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Carniato, Leonardo Ataide. "Robust H∞ switched static output feedback control design for linear switched systems subject to actuator saturation /." Ilha Solteira, 2019. http://hdl.handle.net/11449/183007.
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Orientador: Marcelo Carvalho Minhoto Teixeira<br>Resumo: Este trabalho dedica-se ao estudo do problema de controle robusto envolvendo custo H∞ para sistemas lineares chaveados no tempo contínuo, sujeitos à saturação no atuador e com incertezas politópicas, considerando leis de chaveamento e controladores chaveados dependentes da saída da planta. Os métodos propostos oferecem novas condições baseadas em Desigualdades Matriciais Lineares (LMIs - do inglês, Linear Matrix Inequalities) para o projeto de controladores chaveados utilizando funções de Lyapunov dependentes de parâmetros. O método é baseado em um resultado recentemente introduzido na literatura para o projeto de controle H∞ de saída o qual evita igualdades matriciais lineares (LMEs - do inglês, Linear Matrix Equalities) e a necessidade de impor restrições nas matrizes de saída do sistema, isto é, as matrizes de saída do sistema podem ser de posto linha incompleto. Com o objetivo de estender estes resultados, a restrição de saturação no atuador é estudada. Análises teóricas e resultados de simulações mostram que os novos procedimentos são menos conservativos quando comparados a métodos publicados recentemente na literatura. No método proposto, as condições são uma classe particular de desigualdades matriciais bilineares (BMIs - do inglês, Bilinear Matrix Inequalities), as quais contêm alguns termos bilineares devido à multiplicação de matrizes por escalares. Estes termos estão relacionados à combinação convexa das matrizes de chaveamento bem como a outros parâmetros escalare... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: This thesis is devoted to the study of the robust H∞ control problem of continuous-time switched linear systems subject to actuator saturation with polytopic uncertainties, considering an output-dependent switching law and a switched static output feedback controller. The proposed method offers new sufficient conditions based on linear matrix inequalities (LMIs) for designing the switched controllers using parameter-dependent Lyapunov functions. The method is based on a static output feedback H∞ control design recently presented in the literature that avoids linear matrices equalities (LMEs) and the need to impose any constraints on output system matrices, that is, the output matrices of the system are allowed to be of non-full row rank. In order to extend those results, the actuator saturation constraint is also studied. Theoretical analyses and simulation results show that these new procedures are less conservative than recent methods available in the literature. The conditions of the proposed methods are a particular class of Bilinear Matrix Inequalities (BMIs), which contain some bilinear terms as the product of a matrix and a scalar, related to a suitable convex combination and scalars parameters to provide extra free dimensions in the solution space. The hybrid algorithm Differential Evolution-Linear Matrix Inequality (DE-LMI), is proposed for obtaining feasible solutions of this particular NP-hard problem. Examples show that the proposed methodologies reduce the design ... (Complete abstract click electronic access below)<br>Doutor
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KRISHNA, RAJAN KRISHNA RAJAN. "Hybrid Resistive Switching Devices Based On Soft Nanocomposites." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2705510.
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Questa tesi studia la preparazione e la caratterizzazione del dispositivo di commutazione resistivo ibrido (RSD) a base di nano composito (NC) organico o memristor. La ricerca in questo campo è andata avanti per anni, ma un dispositivo appropriato con un principio di funzionamento unificato non è mai stato sviluppato nella pratica applicazione della memoria. Lo scopo principale dell'attività di ricerca è di fabbricare un RSD basato sul nanocomposito organico e concentrarsi sul suo meccanismo di funzionamento, sulle proprietà del materiale e sulle caratteristiche elettriche in dettaglio. Sono stati condotti numerosi esperimenti per ottenere un dispositivo ibrido ottimizzato che ne misura la durata, la conservazione della memoria, la finestra di memoria (On / Off) ecc. La fase iniziale della ricerca si è occupata dello sviluppo di una RSD simmetrica planare basata su Silver NC. Qui la commutazione resistiva è stata spiegata in termini di formazione indotta da campo di filamento conduttivo lungo i cluster di argento. Questo lavoro consente l'assemblaggio di un dispositivo logico, che presenta un comportamento di commutazione non volatile bipolare che viene controllato mediante l'attuale livello di conformità. Il lavoro è progredito ulteriormente con l'uso di sale d'argento insieme a Ionic Liquid (IL) in varie matrici polimeriche. Questa matrice attiva ha funzionato bene sia su simmetrici (RSD con elettrodi identici) sia su RSD asimmetriche (RSD con elettrodi realizzati in metallo diverso). L'aggiunta di Ionic Liquid a temperatura ambiente svolge un ruolo importante nell'avviare la memoria permanente e ridurre l'intervallo di tensione impostato che è stato un vero colpo d'occhio nel presente lavoro di ricerca. La presenza di ioni d'argento ben dispersi nella matrice polimerica che ha una grande diffusività, aiuta a mantenere gli stati elettrochimici reversibili che immagazzinano informazioni o bit logici sotto forma di filamento conduttivo recuperabile nella nostra matrice di commutazione ibrida basata su polimero. In questo lavoro, presentiamo uno studio dettagliato che mostra l'interazione tra il polimero e le particelle nano mediante varie tecniche. Gli RSD ibridi a matrice di commutazione discussi qui, presentano alcuni dei migliori risultati ottenuti in tutto il mondo nel campo degli RSD ibridi Polimero. Le matrici di commutazione attive preparate durante la nostra ricerca consentono una facile deposizione su vari substrati, ampliando così le potenzialità dell'elettronica stampata. La parte finale della tesi riguarda la fabbricazione e la caratterizzazione di un dispositivo di selezione ibrido a bassa potenza e ad alta velocità.<br>This thesis investigates the preparation and characterization of organic Nano composite (NC) based hybrid Resistive switching device (RSD) or memristor. The research in this field has been going on for years, yet a proper device with a unified working principle has never been developed in practical memory application. The main aim of the research activity is to fabricate an RSD based on organic nanocomposite and to focus on its working mechanism, material properties and electrical characteristics in detail. Several experiments were conducted to obtain an optimized hybrid device measuring its endurance, memory retention, memory window (On/Off) etc. The initial stage of research dealt with the development of a planar symmetric RSD based on Silver NC. Here the resistive switching was explained in terms of field-induced formation of conductive filament along the silver clusters. This work enables the assembling of a logic device, which exhibits a bipolar non-volatile switching behaviour that is controlled by means of the current compliance level. The work further progressed with the use of silver salt along with Ionic Liquid (IL) in various polymeric matrices. This active matrix worked well both on symmetric (RSDs with identical electrodes) as well as on asymmetric RSDs (RSDs with electrodes made different metal). The addition of room temperature Ionic Liquid plays an important role in initiating permanent memory and reducing the set voltage range which was a real eye opener in the present research work. The presence of well dispersed silver ions in the polymer matrix which has a great diffusivity, helps to maintain reversible electrochemical states that store information or logic bits in the form of recoverable conducting filament in our polymer based hybrid switching matrix. In this work, we present a detailed study showing the interaction between the polymer and the Nano particles by means of various techniques. The hybrid switching matrix based RSDs discussed here, present some of the best results obtained worldwide in the field of Polymer hybrid RSDs. The active switching matrices prepared throughout our research enables an easy deposition onto various substrates thus widening printed electronics potentialities. The final part of the thesis deals with the fabrication and characterization of a low power, high speed hybrid selector device.
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GIOVINAZZO, CECILIA. "Resistive switching in ALD metal-oxides with engineered interfaces." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2727227.
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FRA, VITTORIO. "Resistive switching devices with improved control of oxygen vacancies dynamics." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2903510.
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Cristino, Luciana dos Santos. "Bilingüismo e code-switching: um estudo de caso." Pontifícia Universidade Católica de São Paulo, 2008. https://tede2.pucsp.br/handle/handle/13934.
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Previous issue date: 2008-02-11<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>This research aims at investigating the occurrence of code-switching in the
speech of a late bilingual subject, under sociolinguistic and psycholinguistic
perspectives. Code-switching or code alternation is a communicative strategy
used by bilingual speakers in a given social situation. The word bilingual
primarily describes someone who is proficient in two languages. This term can,
however, also include the many people in the world who have varying degrees
of proficiency in three, four or even more languages simultaneously (Wei, 2000)
Adopting the parameters of qualitative research, we have done a case study of
a 39-year-old Nigerian male bilingual who has lived in Brazil for about 6 years
working as an English teacher and is married to a Brazilian. The data was
collected by means of five different instruments: audio and video recording of
an oral presentation of the subject to a group of students in a Brazilian school
in a bilingual context (English/Portuguese), followed by an interview session; a
closed individual interview recorded on audio tape, made by means of discrete
questions; a written questionnaire in order to collect some personal data about
the subject; a visual perception test to detect the preferential language in a free
speech context; and an auto-confrontation or reflexive interview. Only the
passages where the code-switching phenomenon occured were transcribed
and analyzed. Some sentences of this corpus were selected for acoustic
analysis and some charts of duration and F0 measures were made to analyze
some prosody aspects of the native speaker when speaking the first language
and the second language. The final results indicate that: (1) although the
subject prefers the mother tongue (English), code-switching occurs in both
ways: first language second language / second language first-tongue
language; (2) the data analyses suggest that the subject uses different
strategies for choosing lexical items, according to the context, the interlocutor,
and the place, and that the change of the linguistic code appears most of the
time initiated by the OK interjection. The emotional aspect is also worth
mentioning: the subject is always worried about the interlocutor and wants to
know whether he has made himself clear. The pronunciation of Portuguese
words are heavily influenced by his first language; (3) we could observe, from
the acoustic analyses , that the intonation curve of the yes/no questions
produced in English bears much resemblance to English melodic patterning in
that the subject keeps the the intonational aspects of the matrix language; (4)
there is considerable alteration in the fonotaxe of some words used by the
speaker; (5) the altered lexical item is replaced by words belonging to the same
syntactic level<br>Esta pesquisa tem como objetivo investigar a ocorrência de code-switching na
fala de um sujeito bilíngüe tardio (inglês/português), enfocando aspectos
prosódicos e de uso lexical, sob uma perspectiva sociolingüística e
psicolingüística. Code-switching ou alternância no código lingüístico é uma
estratégia comunicativa usada pelo falante bilíngüe de acordo com a situação
socialmente estabelecida. A palavra bilíngüe descreve primariamente alguém
que seja proficiente em duas línguas. Este termo pode porém, ser usado para
incluir muitas pessoas no mundo que tenham diversos níveis de proficiência em
duas, três ou mais línguas simultaneamente (Wei, 2000). Seguindo os
parâmetros da pesquisa qualitativa, fIzemos um estudo de caso de um bilíngüe
do sexo masculino, com 39 anos de idade, nacionalidade Nigeriana, professor
de língua inglesa, residente no Brasil há aproximadamente 6 anos e casado
com uma brasileira. Os dados foram coletados por meio de cinco instrumentos
distintos: gravação em áudio e vídeo de uma apresentação oral do sujeito de
pesquisa acima citado a um grupo de alunos de uma escola brasileira em
contexto bilíngüe (inglês/português), seguida de sessão de perguntas; uma
entrevista fechada individual gravada em áudio, composta por perguntas
pontuais; um questionário escrito para levantamento de dados pessoais do
sujeito da pesquisa; um teste de percepção visual, para detectarmos a língua
preferencialmente escolhida para o discurso livre; e uma auto-confrontação ou
entrevista reflexiva. Foram transcritos e analisados apenas os trechos que
ocorrem o code-switching. Foram selecionadas algumas sentenças deste
corpus para a análise acústica e elaborados alguns gráficos das medidas de
duração de F0 para análise dos aspectos prosódicos do falante nativo quando
produz na primeira língua e na segunda língua. Os resultados obtidos indicam
que: (1) embora o sujeito tenha preferência pela língua materna (inglês), o
code-switching ocorre nos dois sentidos: primeira língua segunda língua /
segunda língua primeira língua; (2) a análise dos dados trouxe à tona que o
sujeito utiliza diferentes estratégias para escolha do léxico, de acordo com o
contexto, do interlocutor, do local, e a mudança do código lingüístico aparece
na maioria das vezes iniciado com a interjeição Ok . A questão emocional
também aparece como um fator: o sujeito sempre se preocupa com o
interlocutor, e com a compreensão das mensagens. A pronúncia das palavras
do português é fortemente influenciada pela primeira língua do sujeito; (3) com
o auxílio da análise acústica pudemos verificar que a curva entoacional de
frases interrogativas totais produzidas em português revelam traços prosódicos
do inglês, ou seja, o sujeito mantém a língua matriz nos aspectos entoacionais;
(4) a fonotaxe sofre alteração em algumas palavras pelo falante utilizada; (5) o
léxico alterado é substituído por palavras do mesmo nível sintático
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Gruson, François. "Modulation naturelle généralisée des convertisseurs matriciels pour la variation de vitesse." Thesis, Ecole centrale de Lille, 2010. http://www.theses.fr/2010ECLI0027/document.
Full textAbstract:
La variation de vitesse des machines électriques est une application très porteuse de l’électronique de puissance. La solution de conversion la plus répandue consiste à connecter en cascade deux convertisseurs statiques et d’effectuer une double conversion (AC/DC/AC). Une autre solution, faiblement répandue dans l’industrie, effectue une conversion directe AC/AC. Ce mémoire effectue une synthèse sur les solutions de conversion directe ainsi que sur les stratégies de modulation des convertisseurs matriciels et matriciels « double étage » dans le but de piloter des machines électriques triphasées à partir d’un réseau alternatif triphasé. Cette synthèse a permis de développer une modulation scalaire généralisée, associée à un modulateur par porteuse, équivalente à la modulation vectorielle et applicable aux différents convertisseurs matriciels. Les modulations, à nombre de commutation réduit par période de découpage, ont été approfondies. Cette généralisation a permis de mettre en évidence une solution réduisant les pertes et améliorant le comportement électromagnétique du dispositif comparativement aux modulations traditionnellement utilisées. La présentation des contraintes réelles (commande rapprochée des interrupteurs, Les protections ainsi que le filtrage) est abordée et a été utilisée pour développer une maquette laboratoire. Les stratégies de modulation ont été implantées expérimentalement et valident l’étude théorique. Enfin, un fonctionnement direct à la fréquence réseau, sans modulation donc à faibles pertes, est proposé. Un fonctionnement particulier est introduit, permettant d’effectuer le transitoire du mode modulé classique au fonctionnement direct non modulé<br>In the power electronics field, the adjustable speed drives is a growing application for electric motors control. The most common conversion solution is to connect in series two static converters and perform a double conversion (AC/DC/AC). Another solution, hardly proposed by industry, uses a direct AC/AC conversion. This thesis aims to make a direct conversion solutions and matrix converters and ‘‘two stage’’ matrix converters modulation strategies synthesis for the purpose to control three-phase electric motor with a three phase input network. This synthesis has developed a generalized scalar modulation, combined with a carrier wave modulator, equivalent to the space vector modulation and applied to matrix converters and the ‘‘two stage’’ matrix converters. Some attention has been done to reduced the switching number during the modulation period. The generalization allows to propose a modified modulation which reduces the losses and improves the electromagnetic performance compared to the traditional modulations used for these kind of converters. The practical constraint (switches control, protection system and filtering) are discussed and has been used to develop a laboratory prototype. The modulations strategies have been implemented experimentally and validate the theoretical study. Finally, a direct function mode with an equal frequency between the input and output network is proposed, without modulation and therefore low losses. In the last part, a particular operation mode is then introduced, permitting the transient operation between the modulated conventional mode to the direct mode without modulation
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MILANO, GIANLUCA. "ZnO nanowires for memristive devices with enhanced functionalities." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2727229.
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Frascaroli, J. "OXIDE-BASED MEMRISTIVE DEVICES BY BLOCK COPOLYMER SELF-ASSEMBLY." Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/356780.
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Oxide-based memristive systems represent today an emerging class of devices with a significant potential in memory, logic, and neuromorphic circuit applications. These devices have a simple capacitor structure and promise superior scalability together with favorable memory performances. This thesis presents a study of resistive switching phenomena in HfOx-based nanoscale memristive devices, with focus on material properties and development of bottom-up approaches for the fabrication of structures with dimension down to the nanoscale.
One of the main issues for practical applications regarding device variability is first assessed by doping hafnium oxide films with different concentrations of aluminum atoms. Testing devices are analyzed by physico-chemical and electrical techniques in order to define the effect of oxide doping on the device properties. In the following part of the thesis, the scalability limit is explored in very high density arrays of nanodevices produced exploiting a lithographic approach based on the bottom-up self-assembly of block copolymer templates. This technique allows a tight control over the size and density of the defined features, and the possibilities offered by block copolymer patterning are here discussed. Electrical measurements of the nanodevices are performed through conductive atomic force microscopy. The device variability is examined and related to the inherent oxide non-homogeneity at the nanoscale, while a non-volatile switching of the resistance of the nanodevices is demonstrated. Further, this analysis draws the attention to a crosstalk phenomenon occurring at the nanoscale in a continuous thin film geometry. This result suggests to select different system configurations. A promising technique based on selective reactions with one copolymer block is finally discussed which allows the direct production of oxide patterns from block copolymer templates avoiding a pattern transfer process. In conclusion, the results reported in this thesis highlight the high scalability potential of oxide-based memristive devices, providing a missing piece of information for the understanding and practical development of very high density arrays.
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Su, Xiaoshan. "Three Essays on the Design, Pricing, and Hedging of Insurance Contracts." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE2065.
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Cette thèse utilise des outils théoriques de la finance, de la théorie de la décision et de l'apprentissage automatique, pour améliorer la conception, la tarification et la couverture des contrats d'assurance. Le chapitre 3 de cette thèse développe des formules de tarification sous forme fermée pour une classe de contrats d'assurance vie participatifs, sur la base de la factorisation matricielle de Wiener-Hopf, et prend en compte plusieurs types de risque, tels que les risques de crédit, de marché et économiques. La méthode de tarification se révèle précise et efficace. Les stratégies de couverture dynamique et semi-statique sont introduites pour aider les compagnies d'assurance à réduire leur risque lié à l'émission de contrats participatifs. Le chapitre 4 traite de la conception optimale de contrats lorsque l'assuré possède une aversion au risque du troisième degré. Les résultats exhibent une forme de contrat optimale pour les agents averses au risque comme pour ceux appréciant le risque dans différents contextes. Le chapitre 5 développe un modèle stochastique amplificateur degradient fréquence/sévérité qui améliore les modèles de fréquence et de sévérité importants et populaires que sont les modèles GLM et GAM. Ce nouveau modèle hérite pleinement des avantages de l'algorithme de renforcement du gradient, dépassant ainsi les formes linéaires ou additives restrictives des modèles GLM et GAM, avec apprentissage de la structure du modèle à partir des données. En outre, ce modèle peut également rendre compte de la dépendance non linéaire existant entre fréquence et sévérité des sinistres<br>This thesis makes use of some theoretical tools in finance, decision theory, machine learning, to improve the design, pricing and hedging of insurance contracts. Chapter 3 develops closed-form pricing formulas for participating life insurance contracts, based on matrix Wiener-Hopf factorization, where multiple risk sources, such as credit, market, and economic risks, are considered. The pricing method proves to be accurate and efficient. The dynamic and semi-static hedging strategies are introduced to assist insurance company to reduce risk exposure arising from the issue of participating contracts. Chapter 4 discusses the optimal contract design when the insured is third degree risk averse. The results showthat dual limited stop-loss, change-loss, dual change-loss, and stop-loss can be optimal contracts favord by both of risk averters and risk lovers in different settings. Chapter 5 develops a stochastic gradient boosting frequency-severity model, which improves the important and popular GLM and GAM frequency-severity models. This model fully inherits advantages ofgradient boosting algorithm, overcoming the restrictive linear or additive forms of the GLM and GAM frequency-severity models, through learning the model structure from data. Further, our model can also capture the flexible nonlinear dependence between claim frequency and severity
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Masoud, Khalid Hasan. "Circuits and controls for grid-connected inverters." Thesis, Queensland University of Technology, 2002.
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CONTI, DANIELE. "Neuromorphic systems based on memristive devices - From the material science perspective to bio-inspired learning hardware." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2711511.
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Hardware computation is facing in the present age a deep transformation of its own paradigms. Silicon based computation is reaching its limit due to the physical constraints of transistor technology. As predicted by the Moore’s law, downscaling
of transistor dimensions doubled each year since the 60s, leading nowadays to the extreme of 16-nm channel width of the present state-of-the-art technology. No further improvement is possible, since laws of physics impose a different electrical
behavior when lower dimensions are attempted. Multiple solutions are then envisaged, spanning the range from quantum computing to neuromorphic computing.
The present dissertation wants to be a preliminary study for understanding the opportunities enabled by neuromorphic computing based on resistive switching memories. In particular, brain inspires technology and architecture of new generation processors because of its unique properties: parallel and distributed computation, superposition of processing and memory unit, low power consumption, to cite only some of them. Such features make brain particularly efficient and robust against degraded data, further than particularly suitable to process and store in memory new nformation. Despite many research projects and some commercial products are already proposing brain-like computing processors, like spiNNaker or IBM’s Bluenorth, they only mimic the brain functioning with standard Silicon technology, that is inherently serial
and distinguish between processing and memory unit. Resistive switching technology on the other hand, would allow to overcome many of these issues, enabling a far better match between biological and artificial neuromorphic computation.
Resistive switching are, generally speaking, Metal-Insulator-Metal structures able to change their electrical conductance as a consequence of the history of applied electric signal. In such sense, they behave exactly as synapses do in a biological
neural networks. For this reason, resistive switching when modeled as memristor, i.e. memory-resistor, can act as artificial synapses and, moreover, are particularly suitable to be interfaced with artificial Silicon neurons that are designed to replicate the biological behavior when excited with electric pulses. Anyhow, from the technological standpoint, there is still no standard on the design and fabrication of resistive switching, so that multiple structure and materials are investigated.
In this dissertation, it is reported an analysis of multiple resistive switching devices, based on various materials, i.e. TiO2, ZnO and HfO, and device architectures, i.e. thin film and nanostructured devices, with the scope of both characterizing and
comprehending the physics behind resistive switching phenomena. Furthermore, numerical simulations of artificial spiking neural networks, embedding Silicon neurons and HfO-based resistive switching are designed and performed, in order to give a systematic analysis of the performances reached by this new kind of computing paradigm.
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Neto, Apiano Ferreira de Morais. "Chaveamento de pulsos ultracurtos em grades de Bragg nÃo-lineares de fibras Ãpticas." Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=173.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>Grades de Bragg nÃo-lineares tÃm sido consideradas desde o final do sÃculo passado para aplicaÃÃes em sistemas de comunicaÃÃes Ãpticas e sensoriamento. O estudo de pulsos ultra-curtos em grades de Bragg lineares, entretanto, sà tem sido considerado nos Ãltimos anos, devido ao desenvolvimento de tÃcnicas numÃricas especÃficas para se resolver o problema.
Neste trabalho, foi realizado um estudo analÃtico-numÃrico das caracterÃsticas de transmissÃo e reflexÃo das grades de Bragg nÃo-lineares. Pela primeira vez, foram consideradas variaÃÃes periÃdicas da nÃo-linearidade no dispositivo operando no regime de onda continua, levando a uma nova classe de grades nÃo-uniformes. CaracterÃsticas dos estados bi- e multi-estÃveis foram extensamente investigados nas grades de Bragg nÃo-lineares.
TambÃm, pela primeira vez, foi realizado o estudo numÃrico de pulsos ultracurtos ($sim$1 ps) incidindo em grades nÃo-lineares. O enfoque foi dado para a dependÃncia da intensidade de um pulso ultracurto ao passar por tal grade. Foram estudadas, ainda, as dependÃncias na forma temporal da profundidade de modulaÃÃo da grade e do Ãndice nÃo-linear. Grades apodizadas foram consideradas, jà que estas sÃo de importÃncia fundamental nos sitemas de comunicaÃÃes modernos.<br>Nonlinear fiber Bragg gratings has been considered since the end of last century for applications in optical communications and sensor techniques. The investigation of ultrashort pulses in linear Bragg gratings, however has been considered in the last few years due the development of specifical numerical techniques to solve this problem.
In the present work an analytical and numerical study of the reflection and transmission characteristics of nonlinear Bragg gratings was done. For the first time, it has been considered periodic variations of the nonlinearity in that devices operating in the continuous wave regime, leading to a new class of nonuniform gratings. It was extensively investigated the bi- and multistable characteristics in these nonlinear fiber Bragg gratings.
Also, for the first time, the numerical study of ultrahsort pulses ($sim$1 ps) incident in nonlinear gratings was done. The focus was the input pulse intensity dependence on that gratings. Also, the depedences in the time shapes of grating index modulation depth and nonlinear index were studied. Apodized gratings were considered since they are of fundamental importance in modern communications systems.
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NGUYEN-THI, Van-Oanh. "SPECTROSCOPIE ET STABILITE DES HYDROCARBURES AROMATIQUES POLYCYCLIQUES DANS LES CONDITIONS DU MILIEU INTERSTELLAIRE." Phd thesis, Université Paris Sud - Paris XI, 2003. http://tel.archives-ouvertes.fr/tel-00005244.
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Ce travail porte sur la dynamique intramoléculaire des Hydrocarbures Aromatiques Polycycliques soumis aux conditions du milieu interstellaire (PAH isolé rotationnellement froid mais vibrationnellement excité). Des études théoriques et expérimentales ont été menées sur leur deux voies de relaxation: émission IR ou fragmentation. Le spectre d'absorption IR a été obtenu par dynamique moléculaire couplée à une méthode semi-classique Adiabatic Switching. La dynamique a été réalisée sur une surface de potentiel semi-empirique Tight-Binding dans le but de simuler tous types de PAHs pouvant dépasser une centaine de carbones (systèmes encore inaccessibles aux expériences et aux calculs ab-inito). Une paramétrisation du potentiel adaptée aux PAHs a été développée ainsi qu'un modèle donnant la densité d'états anharmonique quantique. La simulation spectrale reproduit les grandes tendances en fonction des variables pertinentes en astrophysique: rôle de l'ionisation fort changement de l'allure du spectre et de l'intensité totale absolue), et de la température (décalage vers le rouge, élargissement et modification des intensités des bandes), effet d'anharmonicité (énergie de point zéro, fréquences), et de structure (compacité, cycle pentagonal et taille). La cinétique de fragmentation (induite par absorption séquentielle de photons) d'un hydrogène du cation fluorène (ionisation REMPI) a été étudiée à l'aide d'un jet supersonique et d'un spectromètre de masse. Cette méthode expérimentale originale a permis de déterminer la section efficace absolue d'absorption, d'analyser son atténuation avec le nombre de photons absorbés et l'évolution de la constante de dissociation dans un domaine d'énergie relativement large. Une attention particulière a été portée sur les techniques d'analyse des données. (la loi de Poisson, matrice de branchement, la loi cinétique, matrice d'évolution, simulation de la forme de signaux du spectromètre). Un ajustement libre de la variation de cette constante est proche de celui du modèle statistique PTD mais très différent à basse énergie du modèle RRK. L'énergie d'activation obtenue par ces deux modèles est compatible avec celle déduite du potentiel Tight-Binding.
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WU, HSIAO-CHING, and 吳曉菁. "Using Brand Switching Matrix to Construct Competitive Map." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/55186619910429074660.
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碩士<br>國立臺北大學<br>企業管理學系<br>93<br>Using database to analyze how consumers make their decisions in front of varies brands is rather popular in most western countries but is just an emerging study in Taiwan. Nowadays, studies about brand choice gradually become more important since Taiwan market tends to become channel integration and product variety. Not only manufacturers but also retailers must recognize who the actual competitors are. Hence, they can concentrate limited resources on the right place.
This study uses the scanner panel data of 3C retailer as the tool, chooses AA type alkaline batteries as the example for research, and then finds out customers’ brand choice behavior. There are three main purposes.
(1)Construct brand choice models to compare different customer behaviors among each segment.
(2)Find out the real situation of the battery market by using competitive map.
(3)Measure relative loyalty of each brand in terms of the loyalty map.
After reviewing relative studies, the research method of this study was chosen as follows:
First, use nested logistic model to comprehend customers’ behavior in brand choosing. Second, apply brand-switching matrix to distance matrix by distance formula, and, subsequently, and use MDS (Multi-Dimensional Scaling) to construct competitive map to understand the substitute level from one brand to another. Third, draw brand loyalty map with repurchasing rate and self-price sensitivity. After that, divide the map to four quadrants. The map represents different meaning in terms of dimensions.
Upon the results of the substantial evidence, all research objectives have been achieved. The results were summarized as below:
(1)The brand choice models are valid in all segments.
(2)The competitive map shows the situation of the eight brands at each segment. Taking the total group for example, the keenest competition is found between Duracell small package and Energizer small package.
(3)Among the eight brands, the brand loyalty of Eveready big package is much lower than others, which shows that the company should do something to improve it.
Finally, according to the results of the substantial evidence, we get some derived strategic implications, which are divided into two parts for major manufactures and the 3C retailer to help them make marketing strategies.
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Chen, Yu-Sheng, and 陳. 昱升. "Beam-Switching Planar Antenna arrays with 8x8 Bulter Matrix." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/46462649327627419819.
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碩士<br>國立交通大學<br>電信工程研究所<br>103<br>This thesis is aimed at designing a beam-forming network in a smart antenna switch-beam system, and implementing this design by using a planar antenna array integrated with an 8×8 Butler Matrix. The 8×8 Butler Matrix is able to get a main beam from an antenna array into one of eight various directions.
A tapered slot antenna is used as an antenna array and combined with the 8×8 Butler Matrix in micro-strip lines, which features planarity, simple structure and easily-implemented.
For more details, the theories and features of 8×8 Butler Matrix and tapered slot antenna are introduced in this thesis. Through the simulation and measurement for the design of beam-switched planar antenna array with 8×8 Butler Matrix, this antenna array has been completed during the implementation.
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LI, SHAO-PING, and 李紹平. "Beam-Switching Antenna Array Implemented by Butler Matrix Network." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/ra7792.
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廖昱泰. "Analysis of Board-level Simultaneous Switching Noise with T-Matrix Method." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/78460799095539707964.
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碩士<br>國立交通大學<br>電信工程系<br>91<br>In the multilayer printed circuit board, it is prevalent to use dedicated power/ground planes for power delivery network. On the network, simultaneous switching noise (SSN) is a primary source of electromagnetic interference (EMI) and signal integrity.
In this thesis, we use transmission matrix method to simulate and model SSN problem of power/ground plane structure. With this matrix model, SSN can be efficiently evaluated for both the rectangular and arbitrarily shaped power/ground plane structures.
In the end of this thesis, we use transmission matrix to analyze a familiar power/ground plane design issue: irregular shaped power plane. From the simulation results, we can conclude that a delicate topology for power plane changes the impedance characteristic of problem structure.
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Ho, Tsung-Yuan, and 何宗遠. "Novel 5-GHz Butler Matrix Beamformer with Two-Axis and Three-Axis Beam-Switching Capability." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/89408747760902674950.
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碩士<br>國立交通大學<br>電信工程系所<br>94<br>The switched-beam antenna is one type of the smart antennas, which consists of the antenna array and the beamforming network. Its principle makes use of narrow wave of producing several different directions, pointing to each direction respectively. It is also equal to use N antennas overlay N corn district and can carry out a purpose of tracking the customer by this kind of mechanism.
In this thesis, we propose novel 5-GHz Butler matrix beamformers with two-axis and three-axis beam-switching capability. In the design of 5-GHz Butler matrix beamformer with two-axis, we use two-layer structure to design one set of 4x4 Butler matrix , and implement Butler matrix beamformer with four switch-control circuits to achieve the two-axis beam-switching capability. Besides, by using simple circuits, the SSL (side-lobe level) of each beam is less than -10dB. In the 5-GHz Butler matrix beamformer with three-axis , we use two sets of 8x8 Butler matrix to present structure in the form of 16x16 Butler matrix , by setting up layout of Butler matrix , making use of four sets of antenna array to achieve three-axis beam-switching capability.
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Syu, Yu-Cian, and 徐與謙. "On the design of coupling switching matrix and analysis of shared elements for hybrid electric power conversion." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/723kc8.
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碩士<br>國立虎尾科技大學<br>電機工程系碩士班<br>105<br>With global climate change and the shortage of nonrenewable energy sources, it gives priority to the development of electric vehicle (EV). Various power conversion modules are used in EV, such as the inverter, which changes DC power into AC power. Others are DC-DC converter, which converts battery voltage to other voltage level, and on-board charger, which converts the utility voltage to a battery. More power conversion modules are therefore introduced to achieve higher performance and efficiency. Inside these modules, many devices are of the same functions. With proper hybrid electric power conversion topology and multi-modes control law, the system size and cost can be effectively reduced
In this thesis, a voltage-node-switching analysis and a switching-matrix control method are established. A systematic approach is proposed to integrate different conversion architectures into a single system. Besides, characteristics of the interoperable devices are analyzed and then the motor inductance used as passive element is thoroughly studied. Finally, a hybrid electric power conversion system is realized to verify the proposed approach.
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Lin, Che-Wei, and 林哲維. "Design of a Novel 5-GHz Butler Matrix Beamformer with Two-Axis Beam-Switching Capability and 60GHz Series-Fed Microstrip Array." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/29001949630848492902.
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碩士<br>國立交通大學<br>電信工程系所<br>93<br>In this thesis, we propose a Novel 5-GHz Butler Matrix Beamformer with Two-Axis Beam-Switching Capability and 60GHz Series-Fed Microstrip Array. In the 5-GHz Butler Matrix Beamformer, we use two- layer structure to design a 4x4 butler matrix. We can use two- layer structure to combine two different butler matrices to achieve the two-axis beam-switching capability. Besides, by using simple circuits, the SSL (side-lobe level) of each beam is less than -10dB.
In the 60GHz Series-Fed Microstrip Array, we use seven elements to implement it
, and improve the SSL (side-lobe level) to be less than -18dB.
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Gimode, Jescah Khadi. "A socio-pragmatic and structural analysis of code-switching among the Legoli speech community of Kangeni, Nairobi, Kenya." Thesis, 2015. http://hdl.handle.net/10500/19660.
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The study is an in-depth examination of code-switching in the Logoli speech community in the cosmopolitan Kangemi informal settlement area on the outskirts of the city of Nairobi. The aim of the study is to investigate the sociolinguistic and structural developments that result from urban language contact settings such as Kangemi. The main objective is to identify and illustrate the social motivations that influence the tendency of the Logoli speakers to alternate codes between Lulogoli, Kiswahili and English in the course of their routine conversations as well as the structural patterns that emerge in the process of code-switching. Various methodological techniques were used in the gathering of data, including questionnaire surveys, oral interviews, tape recordings and ethnographic participant-observation techniques are highlighted. Extracts from the corpus were analysed within a theoretical framework based on two models, namely the Markedness Model and the Matrix Language Frame Model, both developed by Myers-Scotton. The study identified and interpreted, within the Markedness Model framework, the key social variables that determine code-switching behaviour among the Logoli speech community. These include age, education, status and the various social domains of interaction. In the light of these factors, the researcher was able to explain the tendency to switch codes in different settings and confirm the study’s assumption that urban-based social factors largely determine the motivations for and the patterns of code-switching. This lead to the conclusion that code-switching is not a random phenomenon but a strategy and a negotiation process that aims at maximizing benefits from interaction. Structural features of the corpus were also identified and analysed within the Matrix Language Frame Model. The assumptions of the model were tested and found to be supported by numerous examples from the data. A number of recommendations were made for further research on minority languages in Kenya and the need for language policy in Kenya to be formulated to take these language groups into consideration.<br>Linguistics and Modern Languages
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Huang, Bo-sheng, and 黃伯昇. "Study of color conversion for display color appearance between three-primary colors and four-primary colors based on the matrix switching method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/05659345597417003090.
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碩士<br>國立成功大學<br>光電科學與工程研究所<br>97<br>In this thesis, our major study is color conversion between three-primary and four-primary colors on the three-primary colors LCD by simulation. Matrix switching algorithm is the tool of color conversion processed in CIEXYZ color space. In order to confirm correctness of color conversion, we simulated and made comparisons of some color patterns on the LCD, which were spatial color mixing with the original three-primary colors and reconstructed four-primary colors, respectively. The pixel unit of four-primary colors was classical Bayer type, which sub-pixels were composed of original RGB stripe sub-pixels of LCD. We also used spectroradiometer to measure color characteristics of studied color patterns.
From experimental results, they show that the measured color values, (x, y) of the same color pattern respectively rendered by three-primary and four-primary colors are very close, but a significantly large luminance difference exists between them. To enhance the luminance of four-primary color patterns, we multiplied a factor in the measured spatially four-primary color spectrum. The value of multiple factor was the average ratio of luminance between three-primary and four-primary in fourteen gray patterns. After luminance compensation, the four-primary color patterns are more consistent with the original three-primary color patterns.
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Mambambo, John. ""Blessed with a curse?" linguistic constraints on the code-switching of bilingual Shona-Xhosa speakers in Cape Town." Diss., 2016. http://hdl.handle.net/10500/22183.
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Completely couched in and steered by the qualitative research method, this study examines the linguistic constraints on the code-switching of the bilingual Shona-Xhosa speakers in Cape Town. The views of the key research participants obtained through participant observation, interviews and questionnaires were heavily relied on. The motivations for the code-switching of the bilingual Shona-Xhosa speakers in Cape Town were explored in this study, including the Shona-Xhosa interlink. Myers-Scotton‟s Markedness theory was scrutinized to discern the assorted social variables motivating the bilingual speakers to code-switch in Cape Town while the Matrix Language Frame Model was used to determine that Shona is the base language and isiXhosa is the embedded language in the Shona-Xhosa code-switching in Cape Town. Diverse linguistic constraints were examined in the context of the Shona-Xhosa code-switching and their universality was disputed. Similarities between Shona and Xhosa were unearthed and the researcher recommends that further Shona-Xhosa studies be pursued.<br>African Languages<br>M.A. (African Languages)
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Parge, Anne. "Current-Induced Excitations in Ferromagnetic Single Layer and Trilayer Nanodevices." Doctoral thesis, 2007. http://hdl.handle.net/11858/00-1735-0000-0006-B459-F.
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