Space shuttle orbiter leading-edge flight performance compared to design goals

Thermo-structural performance of the Space Shuttle orbiter Columbia's leading-edge structural subsystem for the first five (5) flights is compared with the design goals. Lessons learned from thse initial flights of the first reusable manned spacecraft are discussed in order to assess design maturity, deficiencies, and modifications required to rectify the design deficiencies. Flight data and post-flight inspections support the conclusion that the leading-edge structural subsystem hardware performance was outstanding for the initial five (5) flights

Thermodynamic and transport properties of fluids and selected solids for cryogenic applications Summary report, 1 Dec. 1965 - 1 Nov. 1970

Summary data on thermodynamic and transport properties of fluids and solids for cryogenic application

Sub-structural Niching in Estimation of Distribution Algorithms

We propose a sub-structural niching method that fully exploits the problem decomposition capability of linkage-learning methods such as the estimation of distribution algorithms and concentrate on maintaining diversity at the sub-structural level. The proposed method consists of three key components: (1) Problem decomposition and sub-structure identification, (2) sub-structure fitness estimation, and (3) sub-structural niche preservation. The sub-structural niching method is compared to restricted tournament selection (RTS)--a niching method used in hierarchical Bayesian optimization algorithm--with special emphasis on sustained preservation of multiple global solutions of a class of boundedly-difficult, additively-separable multimodal problems. The results show that sub-structural niching successfully maintains multiple global optima over large number of generations and does so with significantly less population than RTS. Additionally, the market share of each of the niche is much closer to the expected level in sub-structural niching when compared to RTS

Economic Impact of Fusarium Head Blight in Malting Barley: Blending Margins and Firm-Level Risk

FHB and DON present significant challenges to producers, grain elevators, and the brewing industry. Yield reductions and price discounts incurred by producers in North Dakota, Minnesota, and South Dakota averaged about $45.3 million annually during the years 1998 through 2000. Losses are more substantial when secondary economic impacts are considered. For every$1 of scab losses incurred by the producer, $2 in losses are incurred in other areas of rural and state economies. One way of mitigating these losses is to blend barley with DON and barley without DON. Results from the grain blending model show a sharp decline of DON discounts and losses after blending. The average discount fell from$0.57/bu to $0.17/bu in 1998,$0.48/bu to $0.14/bu in 1999, and$0.38/bu to $0.15/bu in 2000. However, producers may not benefit from blending margins (gains from improved quality less blending costs) because these margins are the primary source of revenue for grain elevators. It should also be noted that the aggregate costs of DON to grain handlers are difficult to estimate because DON is subject to an unusual amount of measurement uncertainty, and penalties for excess DON pose an unusual level of risk.Crop Production/Industries,

IMPACTS OF DON IN THE MALTING BARLEY SUPPLY CHAIN: AGGREGATE COSTS AND FIRM-LEVEL RISKS

DON is a toxic byproduct of fusarium head blight (FHB), a fungal disease of small grains. Beginning in 1993, a prolonged outbreak of FHB occurred in the Upper Midwest, the traditional source of most six-rowed malting barley produced in the United States. Price discounts associated with DON in barley have been significant. This paper has two objectives. The first is to estimate the impact of DON on the value of malting barley grown in the Upper Midwest. Using crop quality data, we use a linear programming model to derive optimal blends of barley supplies, given discount schedules and the distribution of quality factors. The premise is that blending activities, on a regional scale, allow a larger fraction of the crop to be sold as malting. The second objective is to assess the risks associated with DON in the context of a firm-level blending model. We frame a nonlinear optimization problem in which an elevator seeks to maximize the expected sales value of the barley in its bins. Price discounts for several quality factors are incorporated in the analysis, along with probability distributions for DON. Treating DON as a random quality factor adds some interesting complexity to the standard grain blending problem. Attachments: <a href="/Data/ndsu/aem187a.xls">aem187a.xls</a> <a href="/Data/ndsu/aem187a.xls">aem187b.xls</a> <a href="/Data/ndsu/aem187a.xls">aem187c.xls</a> <a href="/Data/ndsu/aem187a.xls">aem187d.xls</a>barley, malt, DON, fusarium head blight, grain quality, blending, Production Economics,

Feasibility of conventional control techniques for large highly coupled elastic boost vehicles Final report

Control techniques for large highly-coupled elastic boost vehicles with elastic and fuel slosh mode frequencies close to desired control frequencies - motion equation

Influence of data type and rate on short arc lunar orbit determination

Error analysis for selecting optimum rates for taking counted doppler rate and range data for tracking short arc of lunar satellite orbi