The coastal zone is a valuable resource which provides a diversity of benefits. The difficulties facing the coastal zone tend to fall into three categories: (1) Pressure and conflict on resources. The beach residence value, an indicator of land use pressure, implies that, of the Australian states, New South Wales' coastal zone is under the greatest pressure. Associated with population is development pressure. Many forms of development are not compatible, hence conflicts of interest can arise. (2) The dynamic nature of the coast. That is, the physical and biological aspects of the coastal zone are in a state of flux. The dynamics make predictions for management controversial. (3) Organisational problems. The lack of direction, lack of coordination and fragmentation of management leads to ad hoc management of this valuable resource. This evaluation identified and confirmed the relevance of coastal issues which led to the enactment of the Coastal Protection Act, 1979. The coastal issues investigated were: coastal erosion and development; coastal erosion and protection works; coastal land degradation; degradation of coastal habitats, fish and wildlife resources; recreation opportunities; pollution; and increasing population pressure and competition betweeen alternative uses. The administrative arrangements for management of the issues were investigated. A broad range of coastal issues were evaluated using a mix of indicators with standards of comparison to measure progress. Management tools, policies and strategies used to address the issues were investigated. Finally prescriptions to further address the issues were made as was how to implement the prescriptions. The evaluation noted: increasing coastal population and development pressure; numerous examples of conflicts of interest; complex and often bewildering administrative arrangements for coastal zone management; widely varying levels of performance by agencies; and a lack of direction and co-ordination from State authorities. The principal conclusion was that strategic planning needed to be undertaken through a lead coastal agency. The lead agency should clarify and improve direction, co-ordination and co-operation in coastal management. This should improve the effectiveness of management and reduce the incidence and duration of conflict among the different and competing coastal values. This evaluation of the effectiveness of coastal management, at a State level, should not only assist New South Wales but also other States in the management of this valuable resource.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

A numerical model for the cathodic protection of steel in reinforced concrete is developed. Parameters are set to represent a three-dimensional section of a bridge beam exposed to the atmosphere and coated with a thermally sprayed zinc anode. Both diffusion of oxygen and conduction of charge within the concrete are considered explicitly through a two-dimensional finite element model. The diffusivity and conductivity are represented as functions of concrete moisture content. Electrochemical reactions considered at the rebar-concrete interface are reduction of oxygen, oxidation of iron, and evolution of hydrogen in a constant-potential cathodic protection circuit. Reaction-kinetic parameters for actively corroding steel (not passivated steel) are used. Reactions at the zinc-concrete interface are not considered explicitly. The effectiveness of protection is found to vary significantly with both concrete moisture content and position on the rebar. For spatially uniform pore saturation, the drier the concrete is, the greater the corrosion current and the greater the non-uniformity. Protection is significantly more effective at the "front" of the rebar (closest to the zinc anode) than at the "back" (closest to the center of the beam). Corrosion current is greater under drying conditions than under wetting conditions. The numerical model is applied towards interpretation of the "100-mV polarization decay criterion" that is often used to assess the effectiveness of cathodic protection. It is found that the polarization decay predicted from relaxation of oxygen concentration gradients was comparable in magnitude to that observed experimentally, but depends on location on the rebar. A numerical model for the transport of ions in porous concrete under cathodic protection is presented. In this initial model, transport of the ions zinc, calcium, chloride and hydroxide is described by a one-dimensional Nernst-Planck equation at constant current density with generation of zinc ions at the anodic interface, generation of hydroxide ions at the cathodic interface, and no chemical reactions in the bulk of the concrete. The equations are solved numerically by two methods: the point method, in which concentrations and electric potentials are solved for directly through finite-difference approximations of the differential equations and the box method, in which the domain is divided into discrete volume elements with flux balances for each chemical component and for charge. A base grid of 41 nodes is used. Results for the system after 96 and 9600 days of cathodic protection are discussed. Both numerical methods yielded concentration profiles that are virtually indistinguishable. Numerical noise in the box method leads to values in the first and second derivatives of the electric potential that tend to oscillate around the central values represented by the same smooth curve of the point method. In contrast, the point method shows greater apparent numerical deviation from electroneutrality which is largest near the boundaries and decays towards the center in damped oscillations. The deviations decrease with smaller size of grid elements and higher order difference approximations. The magnitude of the charge density in the bulk of the concrete calculated from the second derivative of the electric potential through Poisson's equation is shown to be negligible compared to the overall electroneutrality calculated from the concentrations of ions. At 96 days, the relative contributions of migration and diffusion to the overall flux are shown to vary widely with position and species; migration can neither be neglected nor can a "corrected" Fick's law approach be used. Zinc ions are found to have moved approximately 15 mm into the bulk of the concrete at 96 days. / Graduation date: 2006

Landsliding is a significant contributor to continuous erosion of the 150-mile northern Oregon coast. Direct loss of land to the sea by landslides occurs along 47 percent of the coast. The remaining 53 percent has minor shifting of sand along depositional areas such as spits and dunes. These minor movements alter coastal topography but do not erode material directly into the sea. The type of landsliding is principally controlled by the lithology of the coastline. Landslides are classified on the basis of two features: the lithology of the coastal material in the slide and the type of movement expressed by the overall shape of the slide. Slump occurs in deeply weathered sedimentary rocks and in marine terrace sands overlying seaward-dipping rocks. Rock and debris fall are mainly confined to headlands. Block glides develop along bedding planes of relatively unweathered sandstone. Debris shift occurs in thick terrace and dune sand deposits in which no slip surface is defined. Factors contributing to the cause of coastal landslides include high precipitation, easily weathered rock, and high coastal wave energy. Frequency of reported landslides is related to periods of high precipitation and high wave energy. Although rock weathering is continuous throughout the year, the final phase in disruption of slope equilibrium often occurs during winter storm conditions. Landslides on headlands and adjacent coastlines disrupt the most extensive land area. Wave refraction directly influences this relationship by focusing wave energy on promentories and on the coastline within one mile of the headlands. Distribution of coarse and fine beach material is affected by refraction in restricted coves. Severe coastal erosion has taken place in local areas. The average rates of retreat vary according to the lithology of the coastline, and have been determined as follows: unconsolidated sand and gravel - 23 feet per year; marine terrace sands overlying sandstone and clay - 20 feet per year; marine terrace sands overlying mudstone and sandy shales - 6.5 feet per year. Knowledge of the processes of marine erosion applied to local cliff protection measures can assist in increasing the effectiveness of erosion control attempts. / Graduation date: 1964

Minority children are involved in the child welfare system at rates disproportionate to their numbers in the overall population. Prior research argues that risk assessments conducted by child welfare agencies may be racially biased, and thus contribute to disproportionality. This study seeks to explore the effect of different risk assessment models on racial disproportionality. This is done by examining the relationship between race/ethnicity and various child welfare outcomes in three states that utilize the consensus-based model and three states that utilize the actuarial model of risk assessment. Results were similar for both groups of states, suggesting that one model is not more biased than the other. The results also indicate that racial/ethnic groups enter the child welfare system at different rates. However, groups remained involved in subsequent outcomes at consistent percentages. Finally, the results suggest differential treatment among the most restrictive child welfare outcomes. / McAnulty College and Graduate School of Liberal Arts / Graduate Center for Social and Public Policy / MA / Thesis

A digital watermark is a message robustly hidden within another digitized signal such as an image, a piece of music, a video, etc. . The principal applications of this technology are copyright protection and document fingerprinting. The robustness of watermarking algorithms against common geometrical deformations has drawn the attention of many researchers in the last ten years. Such distortions can result from usual processing of the media and/or malicious manipulations. As an example, a major concern for digital cinema industry is the illicit copy of movies with video cameras taking place in movie theaters. In this scenario, severe geometric distortions can jeopardize the retrieval of the watermark message from the illicit copies. The limitations and weaknesses of the previously proposed solutions to fight these distortions are presented. We developed a generalized construction method for periodic pseudo-random patterns. Based on these patterns, we designed a spread spectrum watermarking scheme with enhanced security properties. We investigated the detection probability and the interaction between exhaustive search and informed coding strategies. Finally, a scheme for the detection of a periodic structure and for the inversion of affine distortions was presented. We showed that the choice of the periodic repetition size involves a trade-off between robustness and secrecy. Thereafter, we studied the security flaw caused by the lack of secrecy in pilot-registration approaches. We proposed an innovative hiding scheme to remedy this issue. Our solution involves the extraction of robust local references from the content of the cover signal. Using this content normalized interpretation, we showed how one can design robust secret binary mask and modulate pilot signals in watermarking schemes. The efficiency of the approach is demonstrated on pilots derived from periodic structures. We also addressed the assessment of the degradation introduced by a geometrical distortion. We assume that a global rigid transform does not impair the perceptual value of an image and we propose a new criterion based on a local analysis of the geometrical deformations.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 168-173). Also available in electronic version.

Thèse (Docteur ès sciences)--Université de Genève, 2002. / Summary in French. "Thèse no 3396." Includes bibliographical references.

No description available.

Current Canadian Building Codes mandate prescribed design requirements for the protection of vertical floor openings by means of draft stops and closely spaced sprinklers. In the event that a design cannot meet the requirements, they also allow for the use of an alternative solution as long as the alternative solution can be proven to provide at least an equivalent level of performance as that prescribed in the Code. A commonly suggested alternative to the use of draft stops includes the construction of a recession at the perimeter of the floor opening; however, the performance of this design relative to that of an equivalent draft stop design has not been thoroughly evaluated. In this research, the available methods for the evaluation of ceiling recession designs are reviewed in order to identify appropriate tools with which to conduct such an analysis. While both analytical analysis and experimental testing could be used, experimental testing of the design is not considered here as this option would not commonly be pursued by design teams due to restrictions on both project budget and design timelines. From the available analytical tools, the fire modeling software Fire Dynamics Simulator (FDS) is selected for evaluation of the ceiling recession design due primarily to the ability of FDS to address complex geometries with appropriate spatial resolution to investigate details of flow and thermal profiles at the ceiling level in a larger compartment. Previous FDS studies are reviewed and an independent validation study is conducted in order to develop an analysis methodology which is appropriate for the evaluation of ceiling recession designs. A case study evaluation is conducted consisting of two dimensionally distinct ceiling recession configurations in the same compartment and two separate source fire heat release rates (HRR). Results are analyzed to evaluate the selected analysis methodology with respect to the characteristics of the simulated flow, and thermal detector response. Results show that the presence of an obstruction to the ceiling jet flow significantly improves thermal detector response where the source fire HRR is low. At higher source fire HRRs, the difference in activation time is found to be minimal amongst configurations of ceiling recession considered in the study. Predictions of thermal detector response time for a selected ceiling recession design are compared to predictions made for code-prescribed draft stop configuration as would be necessary for an alternative solution evaluation. Results indicate that ceiling recession designs provide a reduced level of performance at both low and high source fire HRRs when the thermal detector is placed at the recession ceiling level. In contrast, when the thermal detectors are located at distances greater than 80 mm below the upper ceiling, a design which is permitted by the Code, the performance of the ceiling recession appears better than that of the prescribed draft stop design. Results from the model for detectors placed at distances from the ceiling exceeding 40 mm, however, require further confirmation through experimental testing or additional modeling.