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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Lossless video multiplexing for transport over communication networks.

January 1997 (has links)
by Chan Hang Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 62-68). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of video transmission --- p.1 / Chapter 1.2 --- Previous work on lossless video transmission --- p.4 / Chapter 1.3 --- Central theme of thesis ´ؤ Lossless video Aggregation --- p.5 / Chapter 1.4 --- Organization of thesis --- p.9 / Chapter 2 --- Framework of LVAS --- p.11 / Chapter 2.1 --- Review: Transporting single VBR stream using a CBR channel --- p.11 / Chapter 2.2 --- Lossless aggregation of VBR streams --- p.14 / Chapter 3 --- Minimization of Buffer Size --- p.17 / Chapter 3.1 --- A theoretical approach ´ؤ Dynamic programming --- p.19 / Chapter 3.2 --- A practical heuristic ´ؤ Backward Equalization --- p.21 / Chapter 3.3 --- Simulation results of the heuristic method --- p.24 / Chapter 4 --- Bit-rate allocation with fixed buffer --- p.28 / Chapter 4.1 --- Problem formulation --- p.28 / Chapter 4.2 --- Different bit-rate scheduling methods --- p.33 / Chapter 4.3 --- Speed up using point sampling technique --- p.39 / Chapter 4.4 --- Simulation results --- p.44 / Chapter 5 --- Call Admission and Interactive Control for Video Aggregation --- p.50 / Chapter 5.1 --- Call admission issues --- p.50 / Chapter 5.2 --- Interactive Control --- p.53 / Chapter 5.3 --- CBR and ABR hybrid --- p.54 / Chapter 5.4 --- Simulation results --- p.55 / Chapter 6 --- Conclusions and Future research --- p.57 / Chapter 6.1 --- Future Research Suggestions --- p.58 / Chapter 6.2 --- Publications --- p.60 / Bibliography --- p.62
52

An analytical approach to computer aided diagnosis and tuning of lossy microwave coupled resonator filters.

January 2009 (has links)
Meng, Meng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. [100]-102). / Abstract also in Chinese. / List of tables --- p.iii / List of figures --- p.iv / Introduction --- p.1 / Chapter 1.1 --- Overview of Microwave filters --- p.1 / Chapter 1.2 --- tuning of Microwave filters --- p.3 / Chapter 1.3 --- Rationalization of measured data --- p.6 / Chapter 1.4 --- Contributions of this thesis --- p.8 / Chapter 1.5 --- Organization of this thesis --- p.10 / Coupling matrix extraction methods --- p.11 / Chapter 2.1 --- Basics for coupling matrix synthesis --- p.11 / Chapter 2.2 --- Lossless coupling matrix extraction --- p.14 / Chapter 2.3 --- Lossy coupling matrix extraction --- p.17 / Chapter 2.3.1 --- Effects of dissipation factor --- p.18 / Chapter 2.3.2 --- Determination of dissipation factor --- p.21 / Approximation method single pole --- p.21 / Adjustment method by complex Y parameters --- p.22 / Chapter 2.3.3 --- Coupling matrix synthesis method with loss --- p.25 / Chapter 2.3.4 --- Relations between residues --- p.28 / Chapter 2.4 --- Case of degenerated poles --- p.29 / Chapter 2.4.1 --- The determination of poles --- p.30 / Y parameters interpolation method --- p.30 / Interpolation of denominator of Y parameter --- p.32 / Vector fitting method --- p.34 / Chapter 2.4.2 --- The determination of residues --- p.35 / Data rationalization --- p.39 / Chapter 3.1 --- Quasi-SB-AFS interpolation --- p.40 / Chapter 3.2 --- Removal of phase loading --- p.40 / Asymptote of phase using S parameters --- p.43 / Asymptote of phase using low-pass circuit model --- p.45 / Method of phase loading removal --- p.47 / Chapter 3.3 --- De-embedding of the reference plane --- p.49 / Examples of coupling matrix extraction --- p.57 / A 4th degree DR filter --- p.57 / A 6th degree waveguide filter --- p.62 / An 8th degree waveguide filter --- p.63 / A 10th degree waveguide filter --- p.66 / Filter tuning utilizing coupling matrix extraction --- p.69 / Chapter 5.1 --- Filter tuning strategies --- p.69 / Chapter 5.2 --- Filter tuning examples --- p.71 / Conclusions and discussions --- p.81 / APPENDIX A: Time domain tuning --- p.83 / APPENDIX B: ACME User´ةs Manual --- p.87 / Chapter B.1 --- ACME basics --- p.87 / Chapter B.2 --- Installations --- p.89 / Chapter B.3 --- Getting started --- p.90 / Chapter B.4 --- A hello world example --- p.97 / bibliography --- p.100
53

Network coding for WDM all-optical networks

Manley, Eric D. January 2009 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed October 15, 2009). PDF text: xx, 160 p. : ill. (some col.) ; 1 Mb. UMI publication number: AAT 3360160. Includes bibliographical references. Also available in microfilm and microfiche formats.
54

High performance wavelength-division multiplexing schemes for optical networks

Deng, Xuegong. January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.
55

RWA and wavelength conversion in wavelength-routed all-optical WDM networks /

Chu, Xiaowen. January 2003 (has links)
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 127-134). Also available in electronic version. Access restricted to campus users.
56

Multiwavelength optical sources based on fiber optical parametric process

Wang, Xie, 王勰 January 2014 (has links)
With ever-increasing networking bandwidth demand imposed by data explosion in recent years, optical source generation plays a more and more important role in fiber optical communications. Today wavelength-division-multiplexing (WDM) which refers to encoding independent information onto different wavelengths becomes a widely used technique to increase the transmission bandwidth. However, current WDM system usually requires one single laser source for each distinct wavelength channel which is relatively expensive and cumbersome. Moreover, current WDM system is usually confined to conventional band (C-band) due to the lack of proper gain medium outside C-band. Thus simultaneously generating multiple wavelengths beyond C-band is highly desirable and attractive. Fiber optical parametric amplifier (FOPA) which is based on χ^((3)) nonlinear effect of optical fiber exhibits remarkable properties such as high gain, wide gain bandwidth, and ultra-fast response and could act as a promising candidate for amplifying optical signal beyond C-band. In this thesis I propose and demonstrate several multiwavelength optical sources by taking advantaging of the parametric process. I first experimentally demonstrate the dual-cavity mode-locked FOPO by utilizing two intracavity branches which share the same highly-nonlinear dispersion-shifted fiber (HNL-DSF) as gain medium. Simultaneous generation of 10-GHz pulse train at four different wavelengths located in short wavelength band (S-band) and long wavelength band (L-band) can be achieved. I then introduce the first dispersion distributed FOPO at 10-GHz. With this more advanced cavity configuration, narrower wavelength spacing and wider tuning range in the S- and L-band can be obtained more efficiently in a single cavity. In addition to multiwavelegnth 10-GHz FOPO, multiwavelength FOPO at higher repetition rate beyond C-band is also of great interest in fiber optical communication. I then achieve the first widely tunable 40-GHz dual-wavelength pulsed FOPO. Good quality pulses in both S-and L-band with relatively short duration and low timing jitter can be generated simultaneously. Apart from the parametric process in uniform fiber, I also explore the parametric process in dispersion oscillating fiber (DOF) whose dispersion is periodically modulated along the propagation direction. Based on quasi-phase matched parametric process in DOF, we generate two pairs (quad-wavelength) of modulation instability (MI) side lobes simultaneously. We then numerically and experimentally investigate the spectral correlation between multiple MI by leveraging the dispersive Fourier transformation method. My research efforts presented in this thesis will show the versatility of parametric process for generating multiwavelength optical waves. These schemes have the potential to become efficient optical sources for optical communication beyond C-band. / published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy
57

Dynamic wavelength assignment in WDM passive optical networks

Handley, Michael Robert January 2002 (has links)
This thesis is concerned with the study of dynamic wavelength assignment in wavelength division multiplexed (WDM) passive optical networks (PONs), which is one option for implementing WDM in access networks. A discrete event simulation is developed using the Block Oriented Network Simulator (BONeS) package to compare a WDM PON using dynamic wavelength allocation with one utilizing fixed wavelengths. The model is used in conjunction with a traffic profile constructed using market research data to show bandwidth savings for dynamic assignment of between 4 and 20 % depending on the number of customers and the services distributed. It is shown that the alternative approach of using the Erlang laws underestimates these benefits. An upstream protocol for real-time services with a Fibre To The Cabinet (FTTCab) configuration is developed for single wavelength PONs. It is shown that using connectionbased information does not improve the performance of such a protocol. A segment based protocol which provides timing information on cell arrivals to reduce CDV is modelled and optimized. The results show that a frame of 766 ps divided into 10 segments allows the International Telecommunication Union (ITU) delay and cell delay variation (CDV) targets to be met. The protocol and modelling process is then extended to a WDM system with multiple service classes and non-negligible tuning times. A mechanism for masking tuning latencies which achieves a throughput efficiency of over 98% is designed and modeled. An improvement in performance is then demonstrated for rapid retuning at frame level compared with wavelength assignment at connection set-up. Finally, a new architecture for transferring the tunable devices from the optical network units (ONUs) to the optical line termination (OLT) is proposed. The reduction in the number of tunable components enables cost savings. The efficient transmission of broadcast and multicast traffic is demonstrated using this architecture.
58

High performance wavelength-division multiplexing schemes for optical networks

Deng, Xuegong 09 March 2011 (has links)
Not available / text
59

Resonant-cavity-enhanced surface-emitted second-harmonic generation for optical time-division demultiplexing

Ulmer, Todd G. 12 1900 (has links)
No description available.
60

The application of Kalman filtering to pilot assisted channel estimation for orthogonal frequency division multiplexing

Markus, Patrick Wayne 08 1900 (has links)
No description available.

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