No description available.

No description available.

Thesis (Ph. D.)--Carleton University, 1988. / Also available in electronic format on the Internet.

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Ferri, Bonnie Heck, Committee Member ; Gavrilovska, Ada, Committee Member ; Yalamanchili, Sudhakar, Committee Member ; Schwan, Karsten, Committee Chair.

This dissertation is concerned with the design of a high speed fiber optic campus backbone network which not only provides a high bandwidth connection to various LANs, PBXs, ISDNs, supercomputers, and other high speed computing facilities but also offers an integrated service of voice and data. The campus backbone network is based on an optical fiber dual ring structure. A new token ring protocol based on the IEEE 802.5 standard is proposed as the medium access protocol for the backbone network. In the proposed token ring network, the token holder transmits packets in an exhaustive way when no other nodes want to transmit voice packets. If any node has voice packets waiting for transmission, the token holder can transmit only a single packet during its access opportunity. In this way, not only can the voice delay be bounded at high voice traffic intensities, but a high data throughput can be achieved at low voice traffic intensities. The potential use of Time Division Multiplexing (TDM) was also considered, but the TDM technique was found to be less suitable for our campus environment mainly due to its low efficiency in bursty environments and complex hardware requirements. The backbone network was simulated using the Simscript II.5 discrete event simulation language. The simulation results indicated that the proposed token ring protocol provides satisfactory performances in every respect. A network interface unit (NIU) was designed, which consists of optical transmitter, receiver, and fault tolerance mechanisms as well as the protocol engine. The optimal values of major parameters for the NIU design were determined by the simulation.

The focus of this dissertation is the development of resource management schemes for integrated networks, with the major contributions being: (i) the development of an optimal adaptive buffer management scheme for the packet-switched subsystem, (ii) the integration of a moveable-boundary hybrid switching scheme with the time assigned speech interpolation technique for implementing a congestion control mechanism for the packet-switched subsystem, and (iii) the development of an adaptive hierarchical scheme for implementing the access control and routing functions within the circuit-switched subsystem. The problem of buffer management at an integrated network node is formulated as a nonlinear programming problem with a convex objective function and an interative solution technique with fast convergence is proposed for a real-time implementation of the buffer management scheme in practical environments. In order to exercise an additional degree of control over the packet-blocking probability at each hybrid-switched link within the network, a new multiplexing scheme based on the integration of the moveable-boundary hybrid switching scheme and the time assigned speech interpolation technique is presented in this dissertation. The tradeoff between the corresponding decrease in the packet blocking probability and the increase in the circuit freezeout fraction is demonstrated by a detailed queueing analysis of the multiplexer. Specific algorithms are also presented in this dissertation for the solution of the access control and routing problems within the circuit-switched subsystem. In particular, an access control scheme is developed by solving an integer programming problem formulated using the policy of complete partitioning of the available bandwidth among the competing user classes. As an alternative to the completely partitioned approach, the problem of traffic routing is considered in a network that supports homogeneous traffic classes based on the policy of complete sharing. Finally, for the general case of networks with heterogeneous traffic classes, a hierarchical scheme is developed for the implementation of the access control and the routing functions at two functional levels, where the access control is implemented by the network supervisor who solves an appropriate linear integer programming problem periodically, and the routing function is handled by the individual nodes of the network on a distributed basis. (Abstract shortened with permission of author.)

Primary care clinics are increasingly integrating psychological services into their service programs, however few studies have used a comparison group to demonstrate the effectiveness of these services. This study evaluated the psychological services provided at the Ambulatory Care Clinic (ACC) at the Virginia Commonwealth University Health System (VCUHS) by comparing changes in 147 patients’ PHQ-9 depression scores and GAD-7 anxiety scores over time to the scores of 139 patients at the Hayes E. Willis Health Center, a comparison clinic with demographically similar patients but no integrated psychological services. Assessment data were collected from participants in the ACC at VCUHS during their first or second primary care psychology appointment and during their 3rd-5th appointment. To maximize similarity in baseline levels, participants in the Hayes clinic were matched to participants from the ACC at VCUHS according to their initial levels of depression and anxiety. Participants from the Hayes clinic were then evaluated with follow-up measures of depression and anxiety at approximately the same time interval as their matched counterparts from the ACC at VCUHS. Results indicated that participants from the ACC at VCUHS experienced significantly greater decreases in their depression and anxiety scores compared to participants in the Hayes Clinic. These results remained significant after accounting for participants’ medication for depression and anxiety and participants’ medical diagnoses. The influence of additional mental health services, treatment resistance factors, marital status, employment status, and general demographic variables were also evaluated. This study provided modest preliminary evidence that indicate integration of psychological services is effective. Strengths, limitations, and implications and future directions are discussed.

by Cheung Kam Wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 62-63). / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- ISDN Architecture --- p.4 / Chapter 2.1 --- ISDN Definition --- p.4 / Chapter 2.2 --- Channel Structure --- p.6 / Chapter 2.3 --- Wiring Configuration of ISDN User-Network Interface --- p.6 / Chapter 2.4 --- ISDN Signalling Protocol at S/T Interface --- p.7 / Chapter Chapter 3. --- ISDN Signalling Protocol Enhancement --- p.8 / Chapter 3.1 --- ISDN Basic Rate Access Configuration --- p.8 / Chapter 3.2 --- Protocol Enhancement --- p.10 / Chapter 3.3 --- ISDN Layer 1 Signalling Protocol Enhancement --- p.11 / Chapter 3.4 --- ISDN Layer 2 Signalling Protocol Enhancement --- p.13 / Chapter 3.5 --- ISDN Layer 3 Signalling Protocol Enhancement --- p.15 / Chapter Chapter 4. --- Basic Call Control Procedure for Special Terminal Equipment --- p.18 / Chapter 4.1 --- Signalling Procedure for Call establishment and Termination --- p.18 / Chapter 4.2 --- Requirements on the Developed System --- p.27 / Chapter Chapter 5. --- Software Simulation --- p.29 / Chapter Chapter 6. --- System Performance Analysis --- p.33 / Chapter 6.1 --- Simple Measurement on the Execution Time of ISDN Call --- p.33 / Chapter 6.2 --- Call Handling Capacity Analysis --- p.36 / Chapter 6.3 --- Call Request Delay Analysis --- p.42 / Chapter Chapter 7. --- Conclusion --- p.59 / References --- p.62 / Appendix I: Software Simulation Program Flowchart --- p.64 / Appendix II: Software Simulation Program in Borland C++ Language --- p.86

by Chan-weng Lai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 81-[83]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Where May Soft Multiplexing Occur? --- p.2 / Chapter 1.1.1 --- Multiplexing VC's on to a VP --- p.2 / Chapter 1.1.2 --- Virtual Private Networks --- p.5 / Chapter 1.2 --- Survey of Previously Proposed Hard Multiplexing Schemes --- p.7 / Chapter 1.3 --- Contributions of This Thesis --- p.8 / Chapter 1.4 --- Organization of This Thesis --- p.10 / Chapter 2 --- "Effect of (δ,p) Channels in ATM Networks" --- p.12 / Chapter 2.1 --- Leaky Bucket --- p.13 / Chapter 2.2 --- "(δ, p) Channel" --- p.14 / Chapter 2.3 --- "Comparison of Deterministic VP's and(δ, p) VP's" --- p.17 / Chapter 2.4 --- A Simulation Study : The Effect of δ --- p.20 / Chapter 2.5 --- Summary of This Chapter --- p.23 / Chapter 3 --- Soft-Multiplexing Scheduling Schemes --- p.26 / Chapter 3.1 --- Issues in Soft Multiplexing --- p.27 / Chapter 3.2 --- First Come First Serve (FCFS) --- p.30 / Chapter 3.3 --- Fixed-resource Allocation --- p.32 / Chapter 3.4 --- Excess Token Passing --- p.35 / Chapter 3.5 --- Simulation Results --- p.38 / Chapter 3.6 --- Summary of This Chapter --- p.42 / Chapter 4 --- Analysis of Rate Proportional Token Passing --- p.44 / Chapter 4.1 --- The Fictitious System --- p.45 / Chapter 4.2 --- Leaky-Bucket-Controlled Sources --- p.49 / Chapter 4.3 --- Delay Bound for All Work Conserving Soft Multiplexers --- p.51 / Chapter 4.4 --- The All-Greedy Bound in a RPTP Multiplexer --- p.53 / Chapter 4.5 --- Calculation of the Worst-Case Delay in a RPTP Multiplexer --- p.56 / Chapter 4.6 --- Summary of This Chapter --- p.61 / Chapter 5 --- Implementation of RPTP --- p.63 / Chapter 5.1 --- Virtual Time Implementation --- p.64 / Chapter 5.2 --- Leaky Bucket Implementation --- p.70 / Chapter 5.3 --- Summary of This Chapter --- p.72 / Chapter 6 --- Conclusion --- p.73 / Chapter A --- End-to-end Delay/Backlog Bound in ATM Networks --- p.76 / Bibliography --- p.81

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