by Kwok Chi Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references. / Abstract / Acknowledgements / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Basic Concepts of Lasers and Simple Survey of Laser Theories --- p.4 / Chapter 2.1 --- Introduction --- p.4 / Chapter 2.1.1 --- Basic Structure of a Laser --- p.4 / Chapter 2.1.2 --- "Concepts of "" Mode"" arid "" Mode-Locking""" --- p.6 / Chapter 2.2 --- Brief Review of Laser Theories --- p.9 / Chapter 2.3 --- Other Simple Models --- p.12 / Chapter 2.4 --- Review of the Maxwell-Bloch Equations --- p.17 / Chapter 2.4.1 --- Derivation of Maxwell-Bloch Equations --- p.17 / Chapter 2.4.2 --- Continuous-Wave Operation --- p.23 / Chapter 2.4.3 --- Mean-Field Approximation and Lorenz-Haken Instability --- p.24 / Chapter 2.4.4 --- Adiabatic Elimination of Fast Variables --- p.26 / Chapter 2.4.5 --- Thin-Sheet-Gain Approximation for Multimode Lasers --- p.30 / Chapter 2.4.6 --- Self-Mode-Locking Predicted by Using Maxwell-Bloch Equations --- p.33 / Chapter 2.4.7 --- Hysteresis Phenomena in Switching the Cavity Detuning --- p.35 / Chapter 3. --- "Moving-Mirror ""Mode-Locking""" --- p.41 / Chapter 3.1 --- Conventional Laser Mode-Locking --- p.41 / Chapter 3.1.1 --- Preliminaries： What is Mode-Locking (Conventional) ？ --- p.41 / Chapter 3.1.2 --- Active Mode-Locking and Passive Mode-Locking --- p.43 / Chapter 3.1.3 --- Spectra of Conventional Mode-Locked Lasers --- p.49 / Chapter 3.2 --- Moving-Mirror Mode-Locking --- p.50 / Chapter 3.2.1 --- Historical Notes --- p.50 / Chapter 3.2.2 --- Previously Proposed Explanations --- p.54 / Chapter 3.3 --- MMML Mechanism: our Proposal --- p.59 / Chapter 3.3.1 --- Relation between MMML Lasers and FSFC Lasers --- p.60 / Chapter 3.3.2 --- Concept of Moving Modes --- p.62 / Chapter 3.3.3 --- How are the Moving Modes Locked ？ --- p.64 / Chapter 3.4 --- Numerical Simulations ´ؤ Method and Results --- p.68 / Chapter 3.4.1 --- Description of Our Numerical Model --- p.68 / Chapter 3.4.2 --- Tests on the Simulation Method --- p.71 / Chapter 3.4.3 --- Ultrashort Pulses Generation of a MMML Laser --- p.73 / Chapter 3.4.4 --- Modulation of the Pulses --- p.74 / Chapter 3.4.5 --- Broadband or Discrete Spectra ？ --- p.75 / Chapter 3.4.6 --- Different Operation Regimes in MMML Lasers --- p.79 / Chapter 3.4.7 --- Why Period-T/2 Pulses --- p.84 / Chapter 3.4.8 --- Auto-Correlation Function of the Electric Field --- p.86 / Chapter 3.4.9 --- FSFC Laser with Injection Signal --- p.87 / Chapter 3.4.10 --- MMML in Class C Laser: d = 1.0 --- p.88 / Chapter 3.4.11 --- Exciting the Relaxation Oscillation Resonance --- p.89 / Chapter 4. --- Discussion and Conclusion --- p.92 / Chapter 4.1 --- Limitation of (Conventional) Thin-Sheet-Gain Approximation --- p.92 / Chapter 4.1.1 --- Problem with the Conventional Thin -Sheet-Gain Approximation --- p.92 / Chapter 4.1.2 --- Modified Thin-Sheet-Gain Approximation --- p.93 / Chapter 4.2 --- Concluding Remarks; Possibilities of Further Research --- p.97 / References and Notes / Appendix: Source Codes of the Fortran Program

by Cheng Sze Wan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 72-[76]). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Traffic Scheduling in Input-buffered Switches .。 --- p.3 / Chapter 1.3 --- Organization of Thesis --- p.7 / Chapter 2 --- Principle of Enchanced PIM Algorithm --- p.8 / Chapter 2.1 --- Introduction --- p.8 / Chapter 2.1.1 --- Switch Model --- p.9 / Chapter 2.2 --- Enhanced Parallel Iterative Matching Algorithm (EPIM) --- p.10 / Chapter 2.2.1 --- Motivation --- p.10 / Chapter 2.2.2 --- Algorithm --- p.12 / Chapter 2.3 --- Performance Evaluation --- p.16 / Chapter 2.3.1 --- Simulation --- p.16 / Chapter 2.3.2 --- Delay Analysis --- p.18 / Chapter 3 --- Providing Bandwidth Guarantee in Input-Buffered Switches --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Bandwidth Reservation in Static Scheduling Algorithm --- p.26 / Chapter 3.3 --- Incorporation of Dynamic and Static Scheduling Algorithms .。 --- p.32 / Chapter 3.4 --- Simulation --- p.34 / Chapter 3.4.1 --- Switch Model --- p.35 / Chapter 3.4.2 --- Simulation Results --- p.36 / Chapter 3.5 --- Comparison with Existing Schemes --- p.42 / Chapter 3.5.1 --- Statistical Matching --- p.42 / Chapter 3.5.2 --- Weighted Probabilistic Iterative Matching --- p.45 / Chapter 4 --- EPIM and Cross-Path Switch --- p.50 / Chapter 4.1 --- Introduction --- p.50 / Chapter 4.2 --- Concept of Cross-Path Switching --- p.51 / Chapter 4.2.1 --- Principle --- p.51 / Chapter 4.2.2 --- Supporting Performance Guarantee in Cross-Path Switch --- p.52 / Chapter 4.3 --- Implication of EPIM on Cross-Path switch --- p.55 / Chapter 4.3.1 --- Problem Re-definition --- p.55 / Chapter 4.3.2 --- Scheduling in Input Modules with EPIM --- p.58 / Chapter 4.4 --- Simulation --- p.63 / Chapter 5 --- Conclusion --- p.70 / Bibliography --- p.72

by Chi Sang Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Abstract also in Chinese. / Abstract --- p.ii / Acknowledgements --- p.vii / Table of Contents --- p.viii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Organisation of Thesis --- p.4 / References --- p.6 / Chapter 2 --- Principles and Theories --- p.8 / Chapter 2.1 --- Device Concepts --- p.9 / Chapter 2.2 --- Picosecond Photoconductors --- p.14 / Chapter 2.3 --- Photoconducting Antennas --- p.18 / Chapter 2.4 --- Summary --- p.20 / References --- p.21 / Chapter 3 --- Self-mode-locked Ti:sapphire (Ti:Al203) Laser --- p.24 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Self-mode-locked Ti:sapphire Laser Cavity --- p.26 / Chapter 3.3 --- Negative Dispersion Using Pairs of Prisms --- p.28 / Chapter 3.4 --- Kerr-lens Mode-Locked Model: Role of Space-time Effects --- p.33 / Chapter 3.5 --- Initiation of Self-mode-locked Pulses --- p.37 / Chapter 3.6 --- 39-fs Pulses from A Self-mode-locked Ti:sapphire Laser --- p.38 / Chapter 3.7 --- Summary --- p.42 / References --- p.43 / Chapter 4 --- Photoconductive Detection of Millimetre Waves Using LT-GaAs --- p.46 / Chapter 4.1 --- Introduction --- p.47 / Chapter 4.2 --- Devices Structures --- p.48 / Chapter 4.3 --- Experimental Setup --- p.52 / Chapter 4.4 --- Results and Discussion --- p.54 / Chapter 4.5 --- Summary --- p.57 / References --- p.58 / Chapter 5 --- Investigation of Other Materials for THz Detection --- p.60 / Chapter 5.1 --- Introduction --- p.61 / Chapter 5.2 --- Material Preparation --- p.62 / Chapter 5.3 --- Devices Structures --- p.64 / Chapter 5.4 --- Experimental Setup --- p.68 / Chapter 5.5 --- Results and Discussion --- p.69 / Chapter 5.6 --- Investigation of Other Materials --- p.72 / Chapter 5.7 --- Summary --- p.73 / References --- p.74 / Chapter 6 --- Characteristics of Millimetre Waves --- p.76 / Chapter 6.1 --- Introduction --- p.77 / Chapter 6.2 --- Experimental Setup --- p.78 / Chapter 6.3 --- Experimental Results --- p.80 / Chapter 6.4 --- Experimental Setup --- p.83 / Chapter 6.5 --- Experimental Results --- p.85 / Chapter 6.6 --- Summary --- p.86 / References --- p.87 / Chapter 7 --- Conclusion and Future Work --- p.88 / Chapter 7.1 --- Conclusion --- p.88 / Chapter 7.2 --- Future Work --- p.91 / Appendixes --- p.A-l / Chapter Appendix A: --- Hall Effect Measurement System --- p.A-l / Chapter Appendix B: --- Photography of Device Structures --- p.A-2 / Chapter Appendix C: --- Fast Fourier Transform Program --- p.A-3 / Chapter Appendix D: --- List of Publications --- p.A-4

Although the Maxwell equations govern the propagation of EM waves at all frequencies, the methods required to generate, direct, analyse and detect radiation differ from band to band. This thesis is concerned with the development and demonstration of 'Quasi-optical' techniques for millimetre wavelengths, which involve the propagation of Gaussian profiled beams a few wavelengths across, and the realization of a general circuit approach to mm-wave measurement. Gaussian beam-mode analysis, which is used in later chapters to understand propagation of quasi-optical beams, is reviewed in chapter 1. Chapter 2 outlines the design, manufacture and testing of corrugated feed horns which generate fundamental Gaussian beam-modes. The design and manufacture of lenses which control the spreading of the beams and directional couplers which provide desirable signal processing functions in quasi-optical circuits is discussed in chapter 3. Chapter 4 traces the development of a Faraday isolator which operates in free-space and can suppress unwanted reflections in quasi-optical circuits. Chapter 5 discusses a reusable circuit board upon which systems can be easily and quickly constructed. A null reflectometer built using quasi-optical components is outlined in chapter 6 and reflection measurements from lenses and horns presented. Chapter 7 describes a corrugated feed horn/lens antenna used in a balloon-borne nw-wave cosmic background experiment. Finally, Chapter 8 demonstrates the use of quasi-optical components in a 115 GHz receiver circuit.

Kwok Chi Hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- All-Optical Signal Processing in Optical Communications --- p.2 / Chapter 1.2 --- Fiber-Based Optical Kerr Nonlinear Switches --- p.5 / Chapter 1.3 --- Highly Nonlinear Fibers --- p.6 / Chapter 1.4 --- Objectives and Scope of Study --- p.8 / Chapter 1.5 --- Summary --- p.9 / Chapter Chapter 2 --- Optical Nonlinearity --- p.14 / Chapter 2.1 --- Fiber Nonlinearity --- p.15 / Chapter 2.2 --- Dispersion --- p.21 / Chapter 2.3 --- Cross-Phase Modulation --- p.26 / Chapter 2.4 --- Cross-Polarization Modulation --- p.29 / Chapter Chapter 3 --- Fibers: The Nonlinear Media --- p.47 / Chapter 3.1 --- Average Dispersion --- p.48 / Chapter 3.2 --- Longitudinal Dispersion Map --- p.53 / Chapter 3.3 --- Nonlinear Refractive Index and Nonlinear Coefficient --- p.57 / Chapter 3.4 --- Electrostrictive Contribution --- p.62 / Chapter 3.5 --- List of the Fiber Properties --- p.66 / Chapter Chapter 4 --- Multi-Wavelength Nonlinear Signal Processing --- p.69 / Chapter 4.1 --- Challenge --- p.70 / Chapter 4.2 --- Applications --- p.72 / Chapter 4.3 --- Proposed System Application --- p.110 / Chapter Chapter 5 --- Conclusion and Future Work --- p.114 / Chapter 5.1 --- Comparisons between Proposed and Existing Approaches --- p.114 / Chapter 5.2 --- Conclusion of the Dissertation --- p.115 / Chapter 5.3 --- Prospects and Directions of Future Work --- p.117 / Appdenix A Numerical Model for Dispersion Calculation --- p.I / Appdenix B Simulation Model of Wide Band Cross-Polarization Switch --- p.III / Appdenix C Simulation Model of Spectral Filtering under XPM --- p.VI / List of Publications --- p.IX

Kinetic energy storage via flywheels is an emerging avenue for hybrid vehicle research, offering both high energy and power density compared to more established electric and hydraulic alternatives. However, connecting the high speed flywheel to the relatively low speed drivetrain of the vehicle is a persistent challenge, requiring a transmission with high variability and efficiency. A proposed solution drawing inspiration from the electrical domain is the Switch-Mode Continuously Variable Transmission (SM CVT), which uses a high speed clutch to transfer energy to a torsion spring in discrete pulses with a variable duty cycle. The greatest limitation to the performance of this system is the speed and efficiency of commercial clutch technology. It is the goal of this thesis to develop a novel clutch which meets the actuation speed, controllability, and efficiency requirements of the SM CVT, with potential for reapplication in other rotary mechanical systems with switching functionality. The performance demands of the clutch were derived via a theoretical design case based on the performance requirements of a typical passenger vehicle, indicating the need for a sub-millisecond engagement and disengagement cycle. This is not met by any conventional clutch. Several concepts were considered across the fluid, electromagnetic and mechanical energy domains. A final concept was chosen which employs a friction disk style architecture, with normal force produced by compressing springs via an axial cam mounted to the flywheel. To control duty cycle, the cam was designed with a radially varying profile such that increasing radial position results in proportionally increasing ratio of high dwell to low dwell. Three synchronized followers are then translated radially on the cam by a control linkage. Analysis of the follower train dynamics and system stiffness were carried out to inform the design of a scaled benchtop prototype. Experimental testing was carried out to characterize the performance of the prototype. It was found that the intended functionality of the design was achieved, with discrete energy transfer accomplished via pulsing of the clutch. However, maximum efficiency was only 33% and torque capacity was only 65% of the intended 70Nm. Significant opportunity exists for improvement of the clutch performance in future research.

We have developed a causal model of how various aspects of a computer game influence how much a player enjoys the experience, as well as how long the player will play. This model is organized into three layers: a generic layer that applies to any game, a refinement layer for a particular game genre, and an instantiation layer for a specific game. Two experiments using different games were performed to validate the model. The model was used to design and implement a system and API for Dynamic Difficulty Adjustment(DDA). This DDA system and API uses machine learning techniques to make changes to a game in real time in the hopes of improving the experience of the user and making them play longer. A final experiment is presented that shows the effectiveness of the designed system.

Le sujet de cette recherche, intitulé Temps et Aspect en arabe. Étude comparative avec le français, porte sur une étude comparative du fonctionnement du temps et de l’aspect dans les deux langues. Le présent travail décrit le système temporel de la langue et étudie les procédures de fonctionnement du temps dans le récit et les effets de sens relevant des différentes procédures de l’énonciation du temps.En effet, notre étude n’est pas uniquement une étude à perspective contrastive de l’arabe et du français. Elle a aussi pour but d’éclairer le processus de production écrite des étudiants soudanais quant à l’expression du temps. Nous recueillerons dans un premier temps un corpus de productions écrits d’étudiants soudanais. Nous avons consacré dans un deuxième temps notre étude à un corpus littéraire (deux récits : Saison de la migration vers le nord et Le Messie du Darfour). / The subject of this research, entitled Tenses and Aspect in Arabic: a comparative study with French, consists of a comparative study of the functioning of tenses and aspect in the languages in question. This work describes the tense systems of both languages: it studies howt heses tenses function in narration and the effects of meaning under the different procedures of the enunciation of tenses. However, our study is not only a contrastive study of Arabic and French tenses. It also aims to shed light on the written production process of Sudanese students as regards the expression of tenses. We will first collect a corpus of written productions of Sudanese students. We also based our study on a literary corpus (two stories: Season of the migration to the north and The Messiah of Darfur)

Vi lever idag i ett samhälle där överkonsumtion av kläder blir allt vanligare. Modebranschen erbjuder ett explosivt utbud av kläder, och ”fast fashion” har blivit ett allmänt känt begrepp. Under de senaste åren har dock ett motstånd till detta växt fram: vissa konsumenter blir alltmer medvetna om hur deras egna konsumtionsvanor påverkar både miljön och människor världen över. Massproduktionens- och masskonsumtionens tid förväntas därmed snart vara över, och hållbarhet förutspås bli en så kallad megatrend inom såväl klädbranschen som andra branscher. Det har tidigare genomförts en mängd forskning om hållbarhet och hur detta påverkar konsumenters köpbeslut. Trots att etik och miljö uppmärksammas alltmer menar dock många forskare att det idag finns ett gap mellan konsumenters uttalade omtanke om hållbarhet och deras faktiska ageranden. Många kunder uttrycker en positiv attityd till ämnet och en önskan om att bidra till en hållbar utveckling, men det är fortfarande få som tar hänsyn till detta i sitt beteende. Syftet med vår studie är att bidra till en ökad kunskap om gapet mellan konsumenters uttalade omtanke om hållbarhet och deras faktiska ageranden. Vi har under arbetets gång samarbetat med Nudie Jeans som är ett klädföretag som aktivt arbetar med miljö och etik. Trots sitt ekologiska ställningstagande är dock företaget frågande till hur stor inverkan hållbarhet faktiskt har i deras kunders köpbeslut. Vår studie baseras på en kvantitativ undersökning där empirin utgörs av webbenkäter som skickats ut till ett urval av Nudie Jeans kunder. Det resultat som vår undersökning genererat sammanställdes i datorprogrammet SPSS, och redovisas i ett flertal tabeller. Vi testade även samband mellan ett antal relevanta variabler för att tydligare få svar på vår studies syfte. Resultatet av vår undersökning antyder att det även bland Nudie Jeans kunder finns ett gap mellan uttalad omtanke om hållbarhet och faktiska ageranden. Eftersom urvalet består av Nudie Jeans kunder kan dessa antas ha en positiv inställning till hållbarhet, och ett handlande därefter. Så är dock inte fallet. Vår studie indikerar att respondenterna har en positiv inställning till hållbarhet och en vilja att lägga ner både mer tid och pengar på köp av denna typ av varor. Resultatet pekar även på att hållbarhet är en av de tre viktigaste faktorerna vid köp av såväl kläder generellt som jeans specifik. Dock är det fortfarande något som saknas för att denna positiva attityd ska omvandlas till handling. Den slutsats som kan dras från vår undersökning är att det hållbara klädutbud som marknaden idag erbjuder inte är tillräckligt, både vad gäller estetik och mängd. Existerande modeföretag måste uppenbarligen arbeta för att få en bättre förståelse för vad deras kunder efterfrågar, och därefter utveckla klädkollektioner som stämmer in på detta. / Program: Textilekonomutbildningen

Syfte: Den textila klädmarknaden har under senare år expanderat ochidag har mode en helt annan betydelse än vad det tidigare haft.Trender kommer och går allt snabbare och det blir allt viktigareför konsumenten och därmed företagen att följa med i rådandetrender. Syftet för vår uppsats är att ta reda på hur en trendfaktiskt skapas idag och vilka faktorer som är med och påverkar.Metod: Vår uppsats är byggd på kvalitativa intervjuer med respondentersom verkar på den berörda marknaden. Uppsatsen bygger på etthermeneutiskt synsätt där vi valt att ta fram olika teorier somligger till grund för att svara på vår frågeställning. I vår studievalde vi att beröra ämnet från olika vinklar där både detpsykologiska och sociologiska fick spela en stor roll samt om detfinns ekonomiska drivkrafter bakom trenders uppkomst.Teori: Mode tillhandahåller extra adderat värde till kläder men vilketendast existerar i människans fantasi och freställning.Sociologer studerar mode ur en samhällssynvinkel, men medfokus på att mode påverkas av människor som agerar i grupper.3Psykologer däremot studerar mode utifrån enskilda individersinstinkter och behov. Om man använder det psykologiskaaspekterna som underlag till att studera mode kan man se modesom en del av personligheten inte som ett materiellt ting. Därförhar vi valt att närmare studera, Kimball Young, Sigmund Freudoch Abraham Maslow.Det sociologiska synsättet angriper ur en grupp- ochsamhällssynvinkel. För att förstå processen kring hur trenderskapas och betydelsen av dem kan det underlätta att utforskaden historiska utvecklingen av mode- och textilindustrin.Genom att identifiera de drivande krafterna förr och idag är detlättare att förstå trendernas roll idagEmpiri: I det här avsnittet presenteras vår empiri, uppdelat på varjerespondent och indelat efter fem huvudområden med. Varje delinleds också med en kort presentation av respondenterna, MaudKällqvist, Li Gadd Dackås, Jan Alsén samt Svenska moderådet,för att klargöra relevansen för dennes medverkan samt syntsättoch bakgrund.Slutdiskussion: Trender föds genom olika livsstilar, musik, kultur ochfolkgrupper och blir till trender per definition när aktörer inomtextilbranschen vill föra ut dessa influenser och inspiration tillden stora massan. Då modebranschen, liksom alla branscherstyrs av en ekonomisk bakomliggande drivkraft harkonsekvensen blivit en dynamisk, snabbt föränderlig ochombytlig miljö. Således kan man diskutera huruvida den kreativaprocess och det kreativa behov som en gång givit liv åtmodevärlden fått ge plats för kalkyler, försäljningssiffror ochbörsnoteringar. / Program: Textil produktutveckling med entreprenörs- och affärsinriktning