366 research outputs found
Probabilistic Sensitivity Analysis for Launch Vehicles with Varying Payloads and Adapters for Structural Dynamics and Loads
This paper examines Probabilistic Sensitivity Analysis (PSA) methods and tools in an effort to understand their utility in vehicle loads and dynamic analysis. Specifically, this study addresses how these methods may be used to establish limits on payload mass and cg location and requirements on adaptor stiffnesses while maintaining vehicle loads and frequencies within established bounds. To this end, PSA methods and tools are applied to a realistic, but manageable, integrated launch vehicle analysis where payload and payload adaptor parameters are modeled as random variables. This analysis is used to study both Regional Response PSA (RRPSA) and Global Response PSA (GRPSA) methods, with a primary focus on sampling based techniques. For contrast, some MPP based approaches are also examined
ePortfolios: Mediating the minefield of inherent risks and tensions
The ePortfolio Project at the Queensland University of Technology (QUT) exemplifies an innovative and flexible harnessing of current portfolio thinking and design that has achieved substantial buy-in across the institution with over 23000 active portfolios. Robust infrastructure support, curriculum integration and training have facilitated widespread take-up, while QUTâs early adoption of ePortfolio technology has enabled the concomitant development of a strong policy and systems approach to deal explicitly with legal and design responsibilities. In the light of that experience, this paper will highlight the risks and tensions inherent in ePortfolio policy, design and implementation. In many ways, both the strengths and weaknesses of ePortfolios lie in their ability to be accessed by a wider, less secure audience â either internally (e.g. other students and staff) or externally (e.g. potential employees and referees). How do we balance the obvious requirement to safeguard students from the potential for institutionally-facilitated cyber-harm and privacy breaches, with this generationâs instinctive personal and professional desires for reflections, private details, information and intellectual property to be available freely and with minimal restriction? How can we promote collaboration and freeform expression in the blog and wiki world but also manage the institutional risk that unauthorised use of student information and work so palpably carries with it? For ePortfolios to flourish and to develop and for students to remain engaged in current reflective processes, holistic guidelines and sensible boundaries are required to help safeguard personal details and journaling without overly restricting studentsâ emotional, collaborative and creative engagement with the ePortfolio experience. This paper will discuss such issues and suggest possible ways forward
Optimal Control of Parallel Queues for Managing Volunteer Convergence
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163497/2/poms13224.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163497/1/poms13224_am.pd
Field tests of a pond water treating system
Done under Department of Agricultural Engineering Research Project 155, 'Farm water supplies'--P. [2].Digitized 2007 AES.Includes bibliographical references (page 27)
Organization of the Mouse and Human Carbonic Anhydrase II Genes a
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75491/1/j.1749-6632.1984.tb12355.x.pd
The Value of Inherited Deficiencies of Human Carbonic Anhydrase Isozymes in Understanding Their Cellular Roles a
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73265/1/j.1749-6632.1984.tb12346.x.pd
Matched Filter Stochastic Background Characterization for Hyperspectral Target Detection
Algorithms exploiting hyperspectral imagery for target detection have continually evolved to provide improved detection results. Adaptive matched filters can be used to locate spectral targets by modeling scene background as either structured (geometric) with a set of endmembers (basis vectors) or as unstructured (stochastic) with a covariance or correlation matrix. These matrices are often calculated using all available pixels in a data set. In unstructured background research, various techniques for improving upon scene-wide methods have been developed, each involving either the removal of target signatures from the background model or the segmentation of image data into spatial or spectral subsets. Each of these methods increase the detection signal-to-background ratio (SBR) and the multivariate normality (MVN) of the data from which background statistics are calculated, thus increasing separation between target and non-target species in the detection statistic and ultimately improving thresholded target detection results. Such techniques for improved background characterization are widely practiced but not well documented or compared. This paper provides a review and comparison of methods in target exclusion, spatial subsetting and spectral pre-clustering, and introduces a new technique which combines these methods. The analysis provides insight into the merit of employing unstructured background characterization techniques, as well as limitations for their practical application
Juvenile salmonid distribution, growth, condition, origin, and environmental and species associations in the Northern California Current
Information is summarized on juvenile salmonid distribution, size, condition, growth, stock origin, and
species and environmental associations from June and August 2000 GLOBEC cruises with particular emphasis on differences related to the regions north and south of Cape Blanco off Southern Oregon. Juvenile salmon were more abundant during the August cruise as compared to the June cruise and were
mainly distributed northward from Cape Blanco. There were distinct differences in distribution patterns between
salmon species: chinook salmon were found close inshore in cooler water all along the coast and coho salmon were
rarely found south of Cape Blanco. Distance offshore and temperature were the dominant explanatory variables related to coho and chinook salmon distribution. The nekton assemblages differed significantly between cruises. The June cruise was dominated by juvenile rockfishes, rex sole, and sablefish, which were almost completely absent in August. The forage fish community during June comprised Pacific herring and whitebait smelt north of Cape Blanco and surf smelt south of Cape Blanco. The fish community in August was dominated by Pacific sardines and highly migratory pelagic species. Estimated growth rates of juvenile coho salmon were higher in the GLOBEC study area than in areas farther north. An unusually high percentage of coho salmon in the study area were precocious males. Significant differences in growth and condition of juvenile coho salmon indicated different oceanographic environments north and south of Cape Blanco. The condition index was higher in juvenile coho salmon to the north but no significant differences were found for yearling chinook salmon. Genetic mixed stock analysis indicated that during June, most of the Chinook salmon in our sample originated from rivers along the central coast of Oregon. In August, chinook salmon sampled south of Cape Blanco were largely from southern Oregon and northern California; whereas most chinook salmon north of Cape Blanco were from the Central Valley in California
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