Vertical cable seismic methods are becoming more relevant as we require high quality and high resolution seismic data in both land and marine environments. Our goal in this thesis is to demonstrate the impacts of vertical cable surveying in these areas. Vertical cable methods have been applied to the marine environment with encouraging results. Data quality is similar to that of traditional towed-streamer data, without the long, cumbersome towed-streamers which are difficult to maneuver in congested areas. The current marine vertical cable processing schemes tend to use primaries and receiver ghosts of primaries for imaging. Therefore, we demonstrate the ability of the current multiple attenuation algorithms developed by Ikelle (2001) to preserve either primaries or the receiver ghosts of primaries. As we focus on land acquisition, we discover that vertical cable surveying can overcome many of the traditional problems of land seismics. In fact, our investigations lead us to believe that problems such as ground roll, guided waves and statics can be avoided almost entirely using vertical cable acquisition methods. Furthermore, land vertical surveying is naturally suited for multi-component acquisition and time-lapse surveying. To fully analyze the applicability of vertical cable surveys in marine and land environments, we also investigate the problem of cable spacing and sampling within each cable. We compare the resolution of vertical cable data and horizontal data by calculating the maximum angular coverage of each acquisition geometry and measuring the occurrence of each angle within this coverage, such that more occurrences means better resolution. From our investigations, we find that by using vertical cables of no more than 500 m in length at 500 m intervals, we can acquire higher resolution seismic data relative to horizontal surface methods for an image point, horizontal reflector or a dipping reflector. The key tool used in these investigations is fully elastic finite-difference modeling. We chose this technique based on its ability to properly and accurately model the full wavefield through complex models, all the while preserving amplitudes and the phase of reflected, diffracted and converted wavefields.

Multiple description coding (MDC) has received a lot of attention recently, and has been studied widely and extended to many demanding applications such as speech and video. MDC is a coding technique that generates correlated descriptions of the source stream for transmitting over a diversity system with several channels. The objective of this diversity system is to overcome channel impairments and provide more reliability. In the context of lossy source coding and quantization, a multiple description quantization system usually consists of multiple channels, side encoders to quantize the source samples and send over different channels, and side and central decoders to reconstruct the source. We propose two multiple description quantization schemes in order to design the codebooks and partitions of side and central quantizers of a multiple description system with two channels. The applied framework originated in the multiple description quantization via Gram-Schmidt orthogonalization approach. The basic idea of our proposed schemes is to minimize a Lagrangian cost function by an iterative technique which jointly designs side codebooks and partitions. Our proposed methods perform very closely to the optimum MD quantizer with considerably less complexity. We also propose a multiple description video coding technique motivated by human visual perception. We employ two simple parameters as a measure of the perceptual tolerance of discrete cosine transform (DCT) blocks against visual distortion. We duplicate the essential information such as motion vectors and some low-frequency DCT coefficients of prediction errors into each description, and split the remaining high-frequency DCT coefficients according to the calculated perceptual tolerance parameter. Our proposed technique has very low complexity and achieves superior performance compared to other similar techniques which do not consider perceptual distortion in the design problem. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-08-19 03:33:10.451

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Fishery managers face two problems that are endemic to all renewable resource management: how much of the resource should be extracted, and how should resource users be managed to ensure efficiency and fairness. The predominant fishery management approach addresses these problems through fish stock assessment and resource economics. However, my review of the literature and analysis of the situation in the Danube Delta Biosphere Reserve show that both methodologies face serious difficulties: they deal inadequately with uncertainties about the causes of observed behaviour and the likely effects of different policies; they are too focused on readily measurable objectives; and they do not address the effects of the institutional context on management. In Chapter 3, I examine previous applications of Multiple Criteria Decision Analysis (MCDA) with a view to see if they can be applied to fishery management. My analysis shows that until now MCDA has been used to address only the first two sets of fishery management problems: systematically incorporating uncertainty and multiple objectives into policy development. I also argue that existing proposals for the use of Decision Analysis can be classified as variations of one version of MCDA, namely Multiple Stakeholder Decision Analysis (MSDA). The main problems that remain to be resolved relate to the interaction between experts, stakeholders, and managers when there are conflicting interpretations of evidence, and situations of high institutional inertia. In Chapter 4, I examine these problems within the context of ecological management experience and New Institutional Economics. I argue that for complex problems, such as those in the Danube Delta, management that aims to attain narrowly defined optimal fishing yields through command and control measures is unfeasable and undesirable. A more promising approach would seek to strengthen resilience, promote organisational variety, and increase the leverage of stakeholders over those who provide services for them. When one seeks to achieve such a transformation of management, I argue that the intervention needs to take into account the specific institutional circumstances of the client. In Chapter 5, I show how management procedures, problem perception, and strategy development are influenced by organisational structure and the hierarchical position of managers. That is why decision analysis interventions must address both technical as well as institutional needs of clients. In Chapter 6, I discuss Decision Conferencing, an alternative MCDA approach, and argue that it is more suitable for dealing with management problems such as those of the Danube Delta Biosphere Reserve. Decision Conferences can provide a structure for expert, manager, and stakeholder interaction and can lead to the transformation of social realities. In Chapters 7 and 8, I review the context and concrete environmental and institutional problems that led to the first Decision Conference on an environmental management problem. I report the processes of the Decision Conference, the agreements reached, and anlyse both the short and medium term effects of the intervention. On the basis of that evidence I make claims about the general utility of the approach. The thesis concludes with proposals to improve Decision Conferencing through a framework that provides guidance for context specific process management and helps to ensure that a requisite variety of viewpoints are incorporated into management strategy development.

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This thesis conducts a performance analysis of cognitive transmission in a multiple- cell environment. Most of the cognitive radio (CR)-related research has focused on scenarios where a secondary system operates in the presence of a single primary com- munication system. In this work, we extend the study of a single-cell scenario to a more practical scenario where the secondary system is subjected to two independent primary users (PU). In particular, we investigate the performance of a secondary system operating in an interweaving fashion to explore the spectrum of opportuni- ties. Under the assumption of the Poison traffic model for PU activities, we apply the Markov chain model to first determine the system parameters for combined PUs activities, and then characterize the dynamics of the spectrum opportunities for a secondary user (SU) for both single- and multiple-channel access. To fully inves- tigate the proposed system, we also consider some possible drawbacks and provide corresponding solutions in the extension section. We derive the exact mathematical expressions for the performance metrics, in- cluding average waiting time and average service time of the SU transmission. To enrich the performance analysis, other performance metrics, such as average through- put and collision frequency/ratio are also presented. Through selected numerical examples, we examine the effect of different operation parameters on the SU system performance. We believe that those analytical results can help predict which types of SU applications can be supported under certain practical PU activities. / Graduate

The objective of this research effort is to provide an efficient methodology for a multi-agent robotic system to observe moving targets that are generated from an ablation process. An ablation process is a process where a larger mass is reduced in volume as a result of erosion; this erosion results in smaller, independent masses. An example of such a process is the natural process that gives rise to icebergs, which are generated through an ablation process referred to as ice calving. Ships that operate in polar regions continue to face the threat of floating ice sheets and icebergs generated from the ice ablation process. Although systems have been implemented to track these threats with varying degrees of success, many of these techniques require that the operations are conducted outside of some boundary where the icebergs are known not to drift. Since instances where polar operations must be conducted within such a boundary line do exist (e.g., resource exploration), methods for situational awareness of icebergs for these operations are necessary. In this research, efficacy of these methods is correlated to the initial acquisition time of observing newly ablated targets, as it provides for the ability to enact early countermeasures. To address the research objective, the iceberg tracking problem is defined such that it is re-cast within a class of robotic, multiagent target-observation problems. From this new definition, the primary contributions of this research are obtained: 1) A definition of the iceberg observation problem that extends an existing robotic observation problem to the requirements for the observation of floating ice masses; 2) A method for modeling the activity regions on an ablating source to extract ideal search regions to quickly acquire newly ablated targets; 3) A method for extracting metrics for this model that can be used to assess performance of observation algorithms and perform resource allocation. A robot controller is developed that implements the algorithms that result from these contributions and comparisons are made to existing target acquisition techniques.

One of the numerous results of recent developments in communication networks and distributed systems has been an increased interest in the study of applications and protocolsfor communications between multiple, as opposed to single, entities such as processes and computers. For example, in replicated file storage, a process attempts to store a file on several file servers, rather than one. MUltiple entity communications, which allow one-to-many and many-to-one communications, are known as multicast communications. This thesis examines some of the ways in which the architectures of computer networks and distributed systems can affect the design and development of multicast communication applications and protocols. To assist in this examination, the thesis presents three contributions. First, a set of classification schemes are developed for use in the description and analysis of various multicast communication strategies. Second, a general set of multicast communication primitives are presented, unrelated to any specific network or distributed system, yet efficiently implementable on a variety of networks. Third, the primitives are used to obtain experimental results for a study ofintranetwork and internetwork multicast communications.