Measurements of ocean wave spectra and modulation transfer function with the airborne two frequency scatterometer

The directional spectrum and the microwave modulation transfer function of ocean waves can be measured with the airborne two frequency scatterometer technique. Similar to tower based observations, the aircraft measurements of the Modulation Transfer Function (MTF) show that it is strongly affected by both wind speed and sea state. Also detected are small differences in the magnitudes of the MTF between downwind and upwind radar look directions, and variations with ocean wavenumber. The MTF inferred from the two frequency radar is larger than that measured using single frequency, wave orbital velocity techniques such as tower based radars or ROWS measurements from low altitude aircraft. Possible reasons for this are discussed. The ability to measure the ocean directional spectrum with the two frequency scatterometer, with supporting MTF data, is demonstrated

Cold cathode gauge experiment (ALSEP)

Cold cathode ionization gages were left on the lunar surface as part of ALSEP (Apollo Lunar Surface Experiment Package) on Apollo missions 12, 14, and 15. An instrument prepared for Apollo 13 did not reach the surface because of the abort of that mission. The gages that reached the lunar surface measured the amounts of gas present in the vicinity of the ALSEP sites. The observed daytime gas concentrations were initially about two orders of magnitude greater than the nighttime observations; this was due to contamination of the landing area by the Apollo operations and equipment, and the daytime measurements showed a decrease with time characterized by a time constant of a few months

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

INFLUENCES OF HUMAN CAPITAL AND FARM CHARACTERISTICS ON FARMERS' RISK ATTITUDES

We have two objectives for this paper. The first is to develop an index reflective of farmers' attitudes towards risk. In addition, we show how the risk indices are distributed by size of farm and other farm and operator characteristics, providing information as to how risk management tools may be used, and farm policies targeted. This information will be useful to help explain agricultural sector structural change, such as complex business arrangements arising in agriculture, and household portfolio investment choices.Farm Management, Labor and Human Capital, Risk and Uncertainty,

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,

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