Cellular systems are interference limited in nature. This problem is further accentuated in upcoming commercial wireless standards, which intend to use all the available spectrum in every cell in the network to improve peak data rates. This, however, could lead to considerable interference among neighboring cells, decreasing data rates and causing outages at the cell-edge. Multicell cooperation offers a solution for reducing the high levels of interference. The basic idea is that base stations coordinate transmissions by sharing user information among themselves via backhaul links. With the backhaul being bandwidth limited, cooperative strategies that involve the exchange of only user channel state information (CSI) among base stations offer the best tradeoff between complexity, backhaul load and performance gains. This dissertation focuses on these partial cooperative techniques, known as coordinated beamforming in 3GPP LTE Advanced. In existing frequency division duplex systems, users estimate and feedback the CSI of a single channel over a finite-bandwidth feedback link, using limited feedback techniques. In a multicell cooperative scenario, each user needs to transmit the CSI of multiple channels using the same feedback link. This implies that the available feedback bandwidth must be efficiently shared among different channels to maximize performance gains in the cellular network. This dissertation develops three different approaches to limited feedback in multicell cooperative systems. The first technique, separate quantization, involves each channel being fed back individually using a different codebook. Closed-form expressions are derived to partition adaptively the available feedback bits, as a function of the signal strengths and delays associated with each of the multiple channels. The second strategy is known as joint quantization, where the CSI of all the channels are quantized together as a composite vector. It is shown that though this approach yields higher data rates with smaller feedback requirements than separate quantization, it requires the design and storage of special codebooks. Finally, predictive joint quantization is proposed to exploit the temporal correlation of the wireless channel to reduce feedback requirements significantly as compared to the other two strategies, at the cost of high complexity at the user terminals. / text

Nondeterminism is typically used as an inherent part of the computational models used incomputational complexity. However, much work has been done looking at nondeterminism asa separate resource added to deterministic machines. This survey examines several differentapproaches to limiting the amount of nondeterminism, including Kintala and Fischer's βhierarchy, and Cai and Chen's guess-and-check model.

Doctor of Philosophy / Psychological services in Australia are frequently provided in the context of third party payers who impose time limits based on reasons other than particular client (or therapist) characteristics. Time limits may function as a useful clinical factor in the provision of therapy, for example through accelerating treatment. Less is known about the third party imposition of time limits and the impact they may have on psychotherapy from the perspective of psychologists. The present study investigates the impact of time limits imposed in this manner from the viewpoint of practising psychologists. Practising psychologists took part in a mixed methods study. Twenty seven participated in a semi-structured interview, and eighty-five completed a mailed questionnaire. Interviews were analysed thematically, while both qualitative content analysis and statistical analyses were applied to questionnaires. The interview and questionnaire findings were congruent, both showing that a time limit makes a difference to psychologists. Psychologists are less satisfied with treatment that can be provided in the time limited as opposed to time unlimited context. However, they also perceived benefit in terms of improved client access to psychologists and improvements in the efficiency of therapy. Participants reported that the system of third party referrals had an impact on them that was over and above the impact that a time limit itself had, for example, the fact they were externally managed. The broader context therefore reportedly brought with it the need for psychologists to adapt their treatment to the context of the service. Psychologists reported that, in response to time limits, they often changed their treatment type, for example, from a psychodynamic to cognitive behavioural approach. They also made more general changes, such as moving quicker through the process of therapy and becoming more directive and less client-centred. Perceived outcomes were also affected by the time-limited context. How psychologists conceive of, report, and achieve outcomes is different in this context, and overall outcomes were perceived as weaker. In conclusion, this study has demonstrated that time limits impact upon psychologists in important ways with regard to the process and outcomes of psychotherapy. The broader system of third party referrals has implications for the delivery of psychological services in Australia, which clinical understandings of time limitation have not accounted for. Previous research has shown that the number of sessions available makes a difference, but the present research shows that a time limit cannot be separated from the system under which it is imposed, because once it is imposed, it has implications throughout the whole process.

Zugl.: Bachelorarbeit, 2006

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2007. / Includes bibliographical references.

Fachhochsch., Diplomarbeit, 2006--Bielefeld.

Thesis (M.S. in Defense Analysis)--Naval Postgraduate School, June 2008. / Thesis Advisor(s): Jansen, Erik. "June 2008." Description based on title screen as viewed on August 26, 2008. Includes bibliographical references (p. 49-54). Also available in print.

Project Report (M.Pub.) - Simon Fraser University, 2005. / Project Report (Master of Publishing Program) / Simon Fraser University.

Thesis (doctoral)--Universität Erlangen.

Zugl.: Freiburg (Breisgau), Univ., Diss., 2007/2008