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Complex systems, be they natural or synthetic, are ubiquitous. In particular, complex networks of devices and services underpin most of society's operations. By their very nature, such systems are di cult to conceptualize and reason about e ectively. One seemingly natural notion, which helps to manage complexity and which is commonly found in discussions of complex systems, is that of layering: the system is considered to consist of a collection of interconnected layers that have distinct, identi able roles in the overall operations of the system. Noting that graphs are a key formalism in the description of complex systems, this thesis establishes a notion of a layered graph. A logical characterization of this notion of layering using a non-associative, non-commutative substructural, sepa- rating logic is provided. In addition, soundness and completeness results for a class of algebraic models that includes layered graphs are provided, which give a math- ematically substantial semantics to this very weak logic. Examples in information processing and security are used to show the applicability of the logic. The examples given use an informal notion of action. The thesis also presents a discussion of a number of possible languages that could be used to provide a dynamic extension of the logic. The key components of each language are identi ed and the semantics that would be required in the case of a full, theoretical, development are presented. Examples, mainly in access control, are used to illustrate situations where each extension could be applied. The logic is then used to describe a uniform logical framework for reasoning compositionally about access control policy models. The approach takes account of the underlying system architecture, and so provides a way to identify and reason about how vulnerabilities may arise (and be removed) as a result of the architecture of the system. The logic is then used to describe a uniform logical framework for reasoning compositionally about access control policy models. The approach takes account of the underlying system architecture, and so provides a way to identify and reason about how vulnerabilities may arise (and be removed) as a result of the architecture of the system. Using frame rules, it is also considered how local properties of access control policies are maintained as the system architecture evolves.

by Leung Lee. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references. / Chapter SECTION 1. --- Introduction --- p.1 / Chapter SECTION 2. --- Formulation of Problem --- p.2 / Chapter 2.1 --- Problem Identification --- p.2 / Chapter 2.2 --- Network Planning Parameters and Assumptions --- p.3 / Chapter 2.3 --- Neural Network Model Transformation --- p.5 / Chapter 2.4 --- Algorithm and Implementation --- p.12 / Chapter SECTION 3. --- Simulation Results --- p.15 / Chapter 3.1 --- All Link Costs Are Same or Nearly the Same --- p.17 / Chapter 3.2 --- Fluctuated Cost in One or Two Fibre Paths --- p.18 / Chapter 3.3 --- Sudden Traffic Demand Change in Last Season --- p.19 / Chapter SECTION 4. --- Discussion --- p.20 / Chapter SECTION 5. --- Conclusion --- p.26 / GLOSSARY OF TERMS --- p.27 / BIBLIOGRAPHY --- p.29 / APPENDIX --- p.A1 / Chapter A --- Simulation Results --- p.A1 / Chapter B --- ANN Traffic Routing Example --- p.B1

by Lam Wan. / Thesis submitted in: November 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 96-102). / Abstract also in Chinese. / Part I / Chapter 1 --- Introduction to Integrated Intelligent Personal Communication System --- p.1 / Chapter 2 --- The Switching Architecture --- p.5 / Chapter 2.1 --- The Overall Switching Architecture --- p.6 / Chapter 2.2 --- Switching Module --- p.10 / Chapter 2.2.1 --- Traffic Routing in Switching Module --- p.11 / Chapter 2.2.2 --- Structure of Switching Module --- p.15 / Chapter 2.2.3 --- Wireless Base Interface --- p.16 / Chapter 2.2.4 --- Trunk Interface --- p.18 / Chapter 2.2.5 --- Analog Interfaces --- p.18 / Chapter 2.3 --- Network Intelligence --- p.19 / Chapter 2.4 --- Wireless Part --- p.21 / Chapter 2.4.1 --- Call-Setup in IIPCS --- p.24 / Chapter 2.4.2 --- Handoff --- p.25 / Chapter 2.4.3 --- Wireless Base --- p.27 / Chapter 2.5 --- Downstream Wired Extensions --- p.28 / Chapter 2.6 --- Upstream Wired Part --- p.28 / Chapter 2.7 --- Voice System --- p.28 / Chapter 2.8 --- Features of the IIPCS --- p.29 / Chapter 3 --- Concluding Remarks --- p.33 / Chapter 3.1 --- Summary --- p.35 / Chapter 3.2 --- Directions for Further Research --- p.36 / Part II / Chapter 4 --- Introduction to Next-Generation Switch --- p.37 / Chapter 5 --- Architecture of Next-Generation Switch --- p.41 / Chapter 5.1 --- Overall Architecture of Next-Generation Switch --- p.42 / Chapter 5.1.1 --- Interface module --- p.44 / Chapter 5.1.2 --- Packetizer --- p.46 / Chapter 5.2 --- Concentration Fabric --- p.50 / Chapter 5.3 --- Shared-Buffer Memory Switch --- p.53 / Chapter 6 --- Concentration Networks --- p.56 / Chapter 6.1 --- Background of Concentration Networks --- p.56 / Chapter 6.2 --- k-Sorting --- p.63 / Chapter 6.3 --- Concentrator --- p.72 / Chapter 6.3.1 --- Nk-to-k Concentrator --- p.73 / Chapter 6.3.2 --- Match between Circles with Cost Reduction --- p.75 / Chapter 6.4 --- The Structure of a Molecule --- p.78 / Chapter 6.5 --- Summary --- p.81 / Chapter 7 --- Lock-Latch Algorithm --- p.82 / Chapter 8 --- Performance Evaluation --- p.88 / Chapter 9 --- Concluding Remarks --- p.93 / Chapter 9.1 --- LSI Implementation --- p.94 / Chapter 9.2 --- Summary --- p.95 / Bibliography

Zhang Li. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 71-74). / Abstracts in English and Chinese. / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgments --- p.v / Contents --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Internet Routing and Performance Studies --- p.5 / Chapter 2.1 --- Border Gateway Protocol Version 4 (BGP4) --- p.5 / Chapter 2.2 --- Internet Performance Studies --- p.6 / Chapter 2.3 --- Improve Routing Performance --- p.8 / Chapter 2.3.1 --- Traffic Engineering --- p.8 / Chapter 2.3.2 --- Network-layer Techniques --- p.9 / Chapter 2.3.3 --- Minimum Delay Routing --- p.11 / Chapter Chapter 3 --- Overlay-based Techniques --- p.15 / Chapter 3.1 --- Content Distribution Network --- p.16 / Chapter 3.2 --- Relative Overlay Techniques --- p.16 / Chapter Chapter 4 --- Overlay Minimum Delay Routing --- p.19 / Chapter 4.1 --- Minimum Delay Routing in Overlay Network --- p.21 / Chapter 4.1.1 --- Problem Formulation --- p.21 / Chapter 4.1.2 --- Necessary and Sufficient Conditions for Distributed Computing --- p.25 / Chapter 4.1.3 --- Optimal Overlay Auxiliary Routing (00AR) Algorithm --- p.29 / Chapter 4.2 --- Performance Comparing with Optimal IP routing --- p.31 / Chapter Chapter 5 --- Sub-Optimal Overlay Auxiliary Routing Algorithm --- p.39 / Chapter 5.1 --- Approximation Conditions to Optimal Overlay Routing --- p.40 / Chapter 5.2 --- SOAR algorithm Overview --- p.44 / Chapter 5.3 --- Distributing Traffic over Multiple Paths --- p.49 / Chapter 5.3.1 --- Adaptive load Adjustment --- p.50 / Chapter 5.3.2 --- Per-flow Routing Control --- p.53 / Chapter 5.4 --- Discussion on Marginal Delay of an OAR Link --- p.55 / Chapter Chapter 6 --- Performance Evaluation of Sub-Optimal Overlay Auxiliary Routing --- p.57 / Chapter 6.1 --- Experiment Method Description --- p.57 / Chapter 6.2 --- Comparison of overall delay --- p.61 / Chapter 6.3 --- Effect of the Routing update interval parameters xx and yy --- p.64 / Chapter 6.4 --- Comparison of packet loss rate --- p.66 / Chapter 6.5 --- Comparison of potential maximum data transmission rate --- p.68 / Chapter 6.6 --- Stability of the OAR load-balancing heuristics algorithm --- p.69 / References --- p.71 / Appendix --- p.75

abstract: Emerging modular cable network architectures distribute some cable headend functions to remote nodes that are located close to the broadcast cable links reaching the cable modems (CMs) in the subscriber homes and businesses. In the Remote- PHY (R-PHY) architecture, a Remote PHY Device (RPD) conducts the physical layer processing for the analog cable transmissions, while the headend runs the DOCSIS medium access control (MAC) for the upstream transmissions of the distributed CMs over the shared cable link. In contrast, in the Remote MACPHY (R-MACPHY) ar- chitecture, a Remote MACPHY Device (RMD) conducts both the physical and MAC layer processing. The dissertation objective is to conduct a comprehensive perfor- mance comparison of the R-PHY and R-MACPHY architectures. Also, development of analytical delay models for the polling-based MAC with Gated bandwidth alloca- tion of Poisson traffic in the R-PHY and R-MACPHY architectures and conducting extensive simulations to assess the accuracy of the analytical model and to evaluate the delay-throughput performance of the R-PHY and R-MACPHY architectures for a wide range of deployment and operating scenarios. Performance evaluations ex- tend to the use of Ethernet Passive Optical Network (EPON) as transport network between remote nodes and headend. The results show that for long CIN distances above 100 miles, the R-MACPHY architecture achieves significantly shorter mean up- stream packet delays than the R-PHY architecture, especially for bursty traffic. The extensive comparative R-PHY and R-MACPHY comparative evaluation can serve as a basis for the planning of modular broadcast cable based access networks. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019

A research area that has recently gained great interest is the development of network architectures relating to the tracking of wireless VoIP devices. This is particularly so for architectures based on the popular Session Initiation Protocol (SIP). Previous work, however, in this area does not consider the impact of combined VoIP and tracking on the capacity and call set-up time of the architectures. Previous work also assumes that location information is always available from sources such as GPS, a scenario that rarely is found in practice. The inclusion of multiple positioning systems in tracking architectures has not been hitherto explored. It is the purpose of this thesis to design and test SIP-based architectures that address these key issues. Our first main contribution is the development of a tracking-only SIP based architecture. This architecture is designed for intermittent GPS availability, with wireless network tracking as the back-up positioning technology. Such a combined tracking system is more conducive with deployment in real-world environments. Our second main contribution is the development of SIP based tracking architectures that are specifically aimed at mobile wireless VoIP systems. A key aspect we investigate is the quantification of the capacity constraints imposed on VoIP-tracking architectures. We identify such capacity limits in terms of SIP call setup time and VoIP QoS metrics, and determine these limits through experimental measurement and theoretical analyses. Our third main contribution is the development of a novel SIP based location tracking architecture in which the VoIP application is modified. The key aspect of this architecture is the factor of two increase in capacity that it can accommodate relative to architectures utilizing standard VoIP. An important aspect of all our tracking architectures is the Tracking Server. This server supplies the location information in the event of GPS unavailability. A final contribution of this thesis is the development of novel particle-filter based tracking algorithms that specifically address the GPS intermittency issue. We show how these filters interact with other features of our SIP based architectures in a seamless fashion.

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed December 6, 2007) Includes bibliographical references (p. 60-63).

M.S. / Computer Science and Engineering / Before artificial neural network applications become common there must be inexpensive hardware that will allow large networks to be run in real time. It is uncertain how large networks will do when constrained to implementations on architectures of current technology. Some tradeoffs must be made when the network models are implemented efficiently. Three popular artificial neural network models are analyzed. This paper discusses the effects on performance when the models are modified for efficient hardware implementation.

Thesis (B.A.)--Haverford College, Dept. of Mathematics, 2005. / Includes bibliographical references.