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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Robust incremental relational learning

Westendorp, James, Computer Science & Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Real-world learning tasks present a range of issues for learning systems. Learning tasks can be complex and the training data noisy. When operating as part of a larger system, there may be limitations on available memory and computational resources. Learners may also be required to provide results from a stream. This thesis investigates the problem of incremental, relational learning from imperfect data with constrained time and memory resources. The learning process involves incremental update of a theory when an example is presented that contradicts the theory. Contradictions occur if there is an incorrect theory or noisy data. The learner cannot discriminate between the two possibilities, so both are considered and the better possibility used. Additionally, all changes to the theory must have support from multiple examples. These two principles allow learning from imperfect data. The Minimum Description Length principle is used for selection between possible worlds and determining appropriate levels of additional justification. A new encoding scheme allows the use of MDL within the framework of Inductive Logic Programming. Examples must be stored to provide additional justification for revisions without violating resource requirements. A new algorithm determines when to discard examples, minimising total usage while ensuring sufficient storage for justifications. Searching for revisions is the most computationally expensive part of the process, yet not all searches are successful. Another new algorithm uses a notion of theory stability as a guide to occasionally disallow entire searches to reduce overall time. The approach has been implemented as a learner called NILE. Empirical tests include two challenging domains where this type of learner acts as one component of a larger task. The first of these involves recognition of behavior activation conditions in another agent as part of an opponent modeling task. The second, more challenging task is learning to identify objects in visual images by recognising relationships between image features. These experiments highlight NILE'S strengths and limitations as well as providing new n domains for future work in ILP.
212

West Nile virus in Nevada : mosquito infection rates and weather /

Francis, Stephen Starko. January 2006 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 29-33). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.
213

The contribution of different mechanisms of viral sequence variation to the evolution of positive-sense single-stranded RNA viruses

Pickett, Brett E. January 2010 (has links) (PDF)
Thesis (Ph.D.)--University of Alabama at Birmingham, 2010. / Title from PDF title page (viewed on July 7, 2010). Includes bibliographical references.
214

Performance of Nile tilapia and yellow perch fed diets containing distillers dried grain with solubles and extruded diet characteristics /

Schaeffer, Travis W. January 2009 (has links) (PDF)
Thesis (M.S.)--Wildlife and Fisheries Sciences Dept., South Dakota State University, 2009. / Includes bibliographical references (leaves 80-102). Also available via the World Wide Web.
215

Control over the Nile implications across nations /

Chesire, David K. January 2010 (has links) (PDF)
Thesis (M.S. in Defense Analysis)--Naval Postgraduate School, June 2010. / Thesis Advisor(s): Borer, Douglas A. ; Second Reader: Simons, Anna. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Upstream states, Downstream states, sovereign territory, equitable utilization, national security, conflict, water scarcity, Nile river/basin, hegemony, control, legitimacy, absolute territorial sovereignty, natural rights, absolute integrity, acquired rights, negotiations, contentious agreements, prior appropriation, virtual water, interstate relations, competitive exploitation, political stability/instability, compromise, cooperation, unilateralism, food security, regional security, strategic interests, sustainable exploitation, riparian co-dependence, limited territorial sovereignty, limited integrity, arbitration, asymmetry. Includes bibliographical references (p. 71-74). Also available in print.
216

A GIS model for predicting potential "high risk" areas of West Nile virus by identifying ideal mosquito breeding habitats /

Wallis, Robert Charles January 2005 (has links)
Thesis (M.S.) -- Mississippi State University, 2006. / Includes bibliographical references (p. 91-96). Available online in PDF format.
217

Investigations of the West Nile virus transmission cycle at Medicine Lake National Wildlife Refuge, Montana, 2006-2006

Hale, Kristina Marjorie. January 2007 (has links) (PDF)
Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Gregory D. Johnson. Includes bibliographical references (leaves 60-66).
218

Development of a micropshere-based immunoassay for the detection of IgM antibodies to West Nile virus and St. Louis Encephalitis virus in sentinel chicken sera

Haller, Logan C. January 2006 (has links)
Thesis (M.A.)--University of South Florida, 2006. / Title from PDF of title page. Document formatted into pages; contains 86 pages. Includes bibliographical references.
219

Habitat vulnerability for the Nile crocodile (Crocodylus niloticus) in the Okavango Delta, Botswana

Shacks, Vincent 12 1900 (has links)
Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2006. / The Okavango river along the panhandle of the Delta, in Botswana, is home to many wildlife species as well as to many large village communities. Local communities rely on the riverine system and its resources for subsistence and commerce. Activities associated with the utilization of these resources are governed by the fluctuating water levels of the river, which inhibit access during high water levels and allow access during low water levels. The high intensity of activities, such as reed harvesting, fishing and increased tourism, during low water periods coincides with the breeding season of many wildlife species in the system, including the Nile crocodile (Crocodylus niloticus). Over 90% of crocodile breeding areas in the Delta are found only in the panhandle region. The association between the intensity of human activities in the floodplains and crocodile nesting activity means that much of the habitat required for nesting is vulnerable to human disturbance and this could have severe negative impacts on the future of the Okavango crocodile population. The study evaluated habitat vulnerability by mapping and spatially comparing habitat suitability, based on optimum environmental requirements for crocodile nesting, and human disturbance factors. A detailed crocodile nesting survey was carried out to locate and test all nesting sites according to criteria selected by species experts. The results from the survey were used to locate suitable nesting habitat in the study area by analysis in a Geographic Information System (GIS). Disturbance factors were visually identified and their locations in the study area spatially mapped. Their spatial influences on crocodile nesting were used as factors in a Multi-Criteria Evaluation (MCE) that evaluated the combined effect of the disturbances on the area defined as suitable crocodile habitat. The results indicate the extent of habitat vulnerable to human disturbances. The results from the study show that 59% of once suitable crocodile habitat is currently disturbed by human activities. Most of the remaining 41% of undisturbed habitat is located along the Moremi/Phillipa side channel, which represents a core area for protection measures to be instated. The study recommends the declaration of a crocodile nesting sanctuary in this side channel to ensure the breeding success of this keystone species.
220

Métodos de abate e qualidade da tilápia do Nilo

Santos, Elaine Cristina Batista dos [UNESP] 25 February 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-25Bitstream added on 2014-06-13T19:19:22Z : No. of bitstreams: 1 santos_ecb_dr_jabo.pdf: 578679 bytes, checksum: 657dd6dc624c7974afa4e574d17d045d (MD5) / Este trabalho foi desenvolvido para avaliar a eficiência de três métodos de abate da tilápia do Nilo (Oreochromis niloticus) sobre a qualidade de filés congelados. Esta pesquisa foi executada em duas etapas que consistiram na aplicação dos métodos de abate por eletronarcose (ChE), mistura gasosa (CO2N) e hipotermia (AG). Na primeira etapa foi analisado o peixe inteiro resfriado, avaliados índices de rigor mortis, degradação de ATP, pH, BNV, NNP, contração muscular, cor e texuta instrumental e avaliação sensorial. Os peixes abatidos por ChE apresentaram um retardamento no tempo de entrada em rigor mortis, este mesmo tratamento apresentou R2 de 0,92 na interação entre a degradação de ATP e rigor mortis. O pH foi afetado pelos tratamentos e pelo tempo. Os maiores valores de BNV ocorreram no abate por ChE. O abate por AG apresentou 452 mg NNP/100g. O tempo de estocagem causou uma leve diminuição na textura instrumental no abate por ChE. A L* aumentou com o tempo para os abates por ChE e CO2N. A análise sensorial mostrou um R2 de 0,94; 0,98 e 0,96 para os abates por ChE, CO2N e AG, respectivamente. Na segunda etapa foram aplicados os mesmo métodos de abate da primeira, seguido da filetagem e análises dos filés congelados. Avaliados índices físicos e químicos de qualidade como BNV, TBARS, DSC, CRA, perda de água por cozimento e descongelamento, textura e cor instrumental. Não houve diferença para os valores de BNV. A maior variação de pH ocorreu no abate por AG. Os valores de TBARS foram crescentes ao longo do tempo. O método de abate influenciou a temperatura de desnaturação da actina. A cor L* para o abate por ChE se mantiveram superiores. Ocorreu uma redução significativa na textura. As perdas de água por cozimento e descongelamento e a CRA apresentaram diferença no abate por AG. A partir desses... / This study aimed to evaluate the efficacy of three methods of slaughter of Nile tilapia (Oreochromis niloticus) and the quality of frozen fillets. This research was performed in two steps consisting in applying the methods of killing by electric shock (ChE), gas mixture (CO2N) and hypothermia (AG). The first step was analyzed whole fish cold, evaluated indices of rigor mortis, degradation of ATP, pH, N-BVT NNP, muscle contraction, and texture instrumental color and sensory evaluation. Fish killed by ChE showed a delay in the time of entry into rigor mortis, this same treatment showed R2 0.92 in the interaction between the degradation of ATP and rigor. The pH was affected (p> 0.05) by treatments and time. The highest values occurred in the BNV slaughter by ChE. Slaughter presented by AG 452 mg NNP/100g. The storage time caused a slight decrease in instrumental texture slaughter by ChE. A L* increased with time for slaughter for ChE and CO2N. Sensory analysis showed an R2 0.94, 0.98 and 0.96 for withdrawals by ChE, CO2N and AG, respectively. In the second step we applied the same methods of killing the first, followed by filleting and analysis of frozen fillets. Indices evaluated physical and chemical quality as N-BVT, TBARS, DSC, WRC, cooking and drip loss, texture and instrumental color. There was no difference in the values of N-BVT. The biggest change occurred in pH slaughter by AG. TBARS values were increased over time. The method of killing influence the denaturation temperature of actin. The color L * for slaughter by ChE remained higher. There was a significant reduction in texture. The analysis of cooking and drip loss and WRC differ (p>0.05) at slaughter by mainly AG. From these results it is concluded that is posssible in humanitarian point of view and the quality of the fish, there are feasibility of using electric shock as an... (Complete abstract click electronic access below)

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