The relay channel plays an integral role in network communication systems. An intermediate node acts as a relay to facilitate the communication between the source and the destination. If the rate of codewords is less than the capacity of the source-relay link, the relay can decode the source's messages and forward them to the destination. On the contrary, if the rate of codewords is greater than the capacity of the source-relay link, the relay cannot decode the messages. Nevertheless, the relay can still compress its observations and then send them to the destination. Obviously, if the relay-destination link is of a capacity high enough such that the relay's observations can be losslessly sent to the destination, then the maximum message rate can be achieved as if the relay and the destination can jointly decode. However, when the relay-destination link is of a limited capacity such that the relay's observation cannot be losslessly forwarded to the destination, then what is the maximum achievable rate from the source to the destination? This problem was formulated by Cover in another perspective [7], i.e., what is the minimum rate of the relay-destination link such that the maximum message rate can be achieved? We try to answer this Cover's problem in this thesis. First, a sufficient rate to achieve the maximum message rate can be obtained by Slepian-Wolf coding, which gives us an upper bound on the optimal relay-destination link rate. In this thesis, we show that under some channel conditions, this sufficient condition is also necessary, which implies that Slepian-Wolf coding is already optimal. Hence, the upper bound meets exactly the minimum value of the required rate. In our approach, we start with the standard converse proof. First, we present a necessary condition for achieving the maximum message rate in the single-letter form. Following the condition, we derive a theorem, which is named as "single-letter criterion". The "single-letter criterion" can be easily utilized to verify different channels. Then we show that for two special cases: when the source-relay link and the source-destination link of the relay channel are both binary symmetric channels (BSCs), and when they are both binary erasure channels (BECs), Slepian-Wolf coding is optimal in achieving the maximum message rate. Moreover, the maximum message rates of these two special channels are also calculated in this thesis.

Channel assignment in wireless mesh network (WMN) aims at improving the network throughput by utilizing multiple orthogonal frequency channels to minimize the interference. Interference can be categorized as coordinated and non-coordinated, depending upon the relative location of the interfering links. Compared to coordinated interference, non-coordinated interference has a severe adverse impact on throughput. This thesis is based on the hypothesis that the network throughput can be improved significantly, if channel assignment minimizes non-coordinated interference with priority. We propose a static and centralized channel assignment scheme CCAS to show the effectiveness of the hypothesis. The cluster-based approach of CCAS minimizes non-coordinated interference with reduced complexity. CCAS improves the network throughput by upto 80%, compared to the existing schemes. We propose topology control scheme MATS that constructs low interference multipath network topology using a subset of links from physical topology. We report an additional improvement of upto 10% in the network throughput, when CCAS assigns channels to the links selected by MATS. In the final part of the thesis, we formulate generalized channel assignment as an optimization problem, accounting for real network traffic. The objective of the problem is to select the channels for links such that maximum incident traffic can be transmitted over the links, while ensuring a fair distribution of throughput amongst links and elimination of non-coordinated interference. For a given network and incident traffic, the solution to this problem generates the channel assignment resulting in optimal network throughput. We propose dynamic and distributed scheme LYCAS as an approximate solution to the problem. LYCAS employs MATS to construct network topology and cluster-based approach of CCAS to minimize non-coordinated interference. In addition, it periodically updates the assignment of channels to adapt to the changing traffic load. LYCAS achieves upto 68% of the optimal network throughput and upto 72% of optimal aggregate end-to-end throughput of multi-hop flows. It outperforms the existing schemes by a factor of 2.

The decision to commence the Ord River Irrigation Scheme in the East Kimberley region of Western Australia had extensive political repercussions in national and state politics . The thesis is introduced with an analysis of the decision in relation to the literature of decision making theory, in particul are the two most actively supported decision making theories the rational and the incremental approaches. The thesis demonstrates that the Ord River Scheme accords with the empirical patterns of incremental decision making, The processes of decision making on the Ord River Scheme involved a seemingly endless sequence o f small, incremental and unco-ordinated adjustments on the part of both the Commonwealth and the Western Australian governments. The initial chapters trace the early exploration of the Kimberley region, the state encouraged experiments in tropical agriculture in the 1920's and the early plans for settlement in, and development of the area. Later chapters analyse the main decisions made by both the Commonwealth and Western Australian governments relating to the development of the region - decisions concerning the establishment of Kimberley Research Station, the construction of the Ord River Diversion Dam and early farming developments. The thesis then examines the attempt by both the Commonwealth and Western Australian governments to inject some rationality into the decision making process on the Ord, in the form of cost benefit analysis , the Commonwealth government's agreement of 1967 t o finance the construction of the Main Ord Dam and finally, the Western Australian government's decision in 1974 to abandon cotton growing.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill 6 uppsatser.

Thesis (M.Hous.M.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 73-78) Also available in print.

Thesis (Ph. D.)--Victoria University (Melbourne, Vic.), 2008. / Includes bibliographical references.

Thesis (M. Hous. M.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 71-74).

Thesis (M. Sc.)--University of Hong Kong, 1994. / Includes bibliographical references (leaves 50-54).

Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 207-213).

Thesis (M.S.W.)--University of Hong Kong, 1990.