In the imaging system, a blurred defocus image is a common problem. This is because different objects in the scene need different focus for imaging clearly. However, we can only have one focus distance in one picture. Therefore, the images of the other objects in different focus distance would be blurred by the faulty focuses. We apply wave front coding to solve the above defocus problem. Wave front coding is a technique that adds a phase mask in front of the lens, changing the image performance, and solving the problem of defocus. In this thesis, we used a new phase screen, computed accordingly its optical transfer function and then simulated the resulting images. We compared with other phase screens provided by other researchers for different defocus situations. From our results, our pupil and optical transfer function are slightly superior.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 133-144).

Thesis (M. Sc.)--York University, 2002. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 186-198). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ71626.

published_or_final_version / Architecture / Master / Master of Landscape Architecture

My thesis is to re habitat the grassland of Xilingol League, through the combination of nomadic, local and contemporary landscape technologies to reorganize the utilization of the grassland, aim to get the balance of human-livestock-grassland system for recovery rangeland and give back their pastoral life for the herder’s who living off the grassland. / published_or_final_version / Architecture / Master / Master of Landscape Architecture

The aim of this research is to investigate the social benefits generated by heritage conservation in the Eastern country – China. With economic booming in the urban area, the cultural built heritage is hardly got properly conservation resulting from primarily considering economic benefits other than environmental or social benefits. Nowadays, the social benefits have been recognized by experts and governments; however few studies were conducted in developing or Eastern countries. Thus, this research is appealing a completed picture of heritage conservation in China. This research was based on a review of relevant literature, in which heritage conservation, social benefits of heritage conservation and conservation in China are discussed. Case study is adopted in this research and Gulou area, since it is one of representative heritage conservation in China whose renew project draws much focus. Questionnaires are delivered to local residents in the site of case study –Gulou area in Beijing, China, together with several interviews. The findings underline that the social benefits mentioned in the contemporary literature are partly achieve in practice. Education about the heritage and public participation are particularly lacking. The main conclusion to be drawn from this work is that heritage-related celebrations and completed exhibition should get more consideration in heritage conservation, while there are constrains to conduct. / published_or_final_version / Housing Management / Master / Master of Housing Management

This research explores whether digital records created and used in environments without explicit record-keeping rules provide evidence of the organization that creates them and can be preserved in the long term. I studied the formation process of a digital archive that belonged to a philanthropic organization in Argentina. This archive originated in the late 1980s and was added to until 2005, a period during which, as information technologies were being massively adopted in the work-place, new problems were compounded by the nature and conditions of its electronic records and database systems. The study revealed knowledge about the information technologies and social practices used in the archive's development, providing an understanding of the path from its past to its present form and insights about how to preserve it. The attributes characterizing this archive led to developing the concept of a natural electronic archive. To determine whether the records in the natural archive reflect the organization that created them I devised an inductive appraisal method that uses text mining, social network analysis, and visualization methods. I calculated the similarity between the text records created, gathered, and shared by them within frameworks of time and provenance as a measure of the strength of the relationships between staff members and the functions that they represented. Results of mining electronic text records belonging to 10 years of activities in the organization indicate that it is possible to observe changes in work-dynamics and roles in a way that goes beyond the typical organizational chart. The process and challenges involved in developing and validating the appraisal method are reported in this dissertation. Studying the archive's formation process allowed gaps in the technical documentation to be filled and suggested a preservation strategy. The goal of the strategy is to preserve the structure and context in which the electronic records and databases were created and used, while moving them into a new and compatible technical environment to allow continuous access. From a practical perspective the strategy allows studying the effects of hardware and software migration on file formats and databases present in the digital archive. From a broader perspective it aims to provide a theoretical understanding of the relationship that exists between digital information creation and use and preservation strategies. / text

No description available.

Best practices for Restoration Ecology have been largely derived from case studies. Novel Ecosystems is an approach that has the possibility of providing the field of restoration research with both structure and a road map for ecological recovery. In December 2015, Ontario Parks will be ceasing the lease of approximately 122 ha of farmland within Boyne Valley Provincial Park. My thesis aims to bridge the gap between social and ecological systems and build a resilient restoration project at Boyne Valley Provincial Park. My approach integrated the best case scenarios from each the social and ecological aspects to determine a restoration plan. From the social aspect, I chose the method photo-elicitation to bridge the communication gap between myself, the researcher, and the interviewees. Semi-structured interviews were conducted with six major stakeholders including a farmer who is currently leasing land within Boyne Valley Provincial Park, a frequent hiker of the Ontario Parks’ trail system, an academic researcher for Ontario Parks, and three Ontario Parks’ personnel to understand the different landscape preferences of stakeholders within Boyne Valley Provincial Park. From the ecological aspect, I examined the success of restoration for the first year after a fall planting in terms of species richness and percent cover for all species, including native species (planted and not planted) and non-native species across three fields with different initial conditions. To test which species should be used as the initial ground cover after farming has ceased, I looked at the survivorship and growth of five species: Danthonia spicata, Elymus trachycaulus ssp. trachycaulus, Sporobolus cryptandrus, Monarda fistulosa and Penstemon hirsutus. My recommendations for restoration at Boyne Valley Provincial Park include implementing the restoration efforts at a smaller scale to start. The remaining fields should continue to be farmed until restoration can commence or mowed at least four times a year before seeds are formed. Open communication should continue between all stakeholders. Soil preparation should include tilling the soil prior to planting only if the land was left abandoned (e.g. old-field). A plant composition survey should be conducted prior to restoration – more particularly in hay fields - to determine if native meadow species are found. If native meadow species are present (e.g. Sisyrinchium montanum) that would not survive tilling, a no-till planting method may be a better option than tilling. Acknowledging these are early results, my initial recommendation based on survivorship and growth for the first year after planting would be to use plant plugs for Elymus trachycaulus ssp. trachycaulus and a combination of plant plugs and seeds for Monarda fistulosa and Penstemon hirsutus. Future studies should incorporate other herbaceous species to increase the biodiversity while choosing flowers that bloom at different times. Additionally, pilot studies should be completed at all Ontario Parks locations where agriculture leases are ending to develop restoration methodologies that are applicable across Ontario. Information on each of the species to be planted should be distributed to the farmers that border Ontario Parks’ boundaries. This information should include at minimum the species life history, dispersal mechanisms, and a photograph. The research in this thesis outlines initial restoration efforts to guide restoration recommendations for the first year after land abandonment. Much longer-termed research is necessary to understand community dynamics and potential recovery of system.

Restored plant populations frequently fail to establish or don’t persist over short to intermediate periods of time. These unsuccessful restoration attempts may be the result of strong selection and a high degree of maladaptation within restored populations. There are various potential evolutionary causes of maladaptation within restored systems, which may ultimately lead to extirpation. Here, I investigated whether current restoration practises systematically lead to stronger selection and a greater magnitude of maladaptation, by comparing restored prairie populations of Monarda fistulosa to naturally occurring populations. Phenotypic selection and maladaptation analyses were conducted on nine ecologically important traits in three restored and three natural tall grass prairie populations. Significant differences in selection and maladaptation were detected among the six study populations; however there was no significant difference between restored and natural populations. The lack of difference may indicate that the restored populations are well adapted to their environment or that natural populations are less well adapted than assumed.