Flight evaluation of a computer aided low-altitude helicopter flight guidance system

The Flight Systems Development branch of the U.S. Army's Avionics Research and Development Activity (AVRADA) and NASA Ames Research Center developed for flight testing a Computer Aided Low-Altitude Helicopter Flight (CALAHF) guidance system. The system includes a trajectory-generation algorithm which uses dynamic programming and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and precision navigation information to determine a trajectory between mission waypoints that seeks valleys to minimize threat exposure. This system was developed and evaluated through extensive use of piloted simulation and has demonstrated a 'pilot centered' concept of automated and integrated navigation and terrain mission planning flight guidance. This system has shown a significant improvement in pilot situational awareness, and mission effectiveness as well as a decrease in training and proficiency time required for a near terrain, nighttime, adverse weather system

Alien Registration- Clark, Raymond H. (Corinna, Penobscot County)

https://digitalmaine.com/alien_docs/9842/thumbnail.jp

Alien Registration- Clark, Raymond H. (Castle Hill, Aroostook County)

https://digitalmaine.com/alien_docs/26342/thumbnail.jp

A descriptive and evaluative bibliography of mathematics filmstrips.

Submitted by A.W. Clark and R.W. Allen for the degree of Master of Arts and by C.H. Gardner and R.F. Sweeney for the degree of Master of Education. Thesis (Ed.M.)--Boston UniversityThe purpose of this paper is to present in one volume (1) a bibliography of all mathematics filmstrips from those suitable for the first grade to those suitable for use in senior high school and college, (2) an accurate description of each filmstrip, and (3) unbiased evaluations of each filmstrip by qualified teachers invited to take part in the project. Concomitant problems. The foregoing three parts were the heart of the problem and the portion nearly completely solved. There were, however, concomitant problems which have been partially solved by this work. The first of these concerns the limited use of filmstrips by mathematics teachers. Undoubtedly many do not believe in using filmstrips in mathematics classes. Others have never given serious thought about the advisability of using filmstrips. In later sections of this chapter and throughout this work evidence is cited to support the contention that filmstrips should have serious consideration, and that they are useful in mathematics classes. The second concomitant problem concerns the revision of current filmstrips and production of new ones. The filmstrip producers were supplied, upon their request, with summaries of the evaluations. Summaries were supplied only at the producer's request; for unless they were interested enough to request the summaries, they probably would not be interested in changing or improving their filmstrips. Summary. The problem, then, had three major parts: listing , describing, and evaluating mathematics filmstrips, and two concomitant parts: arousing the mathematics teacher's interest in filmstrips, and encouraging producers to make better productions and necessary revisions in current productions. [TRUNCATED

Computation of vertical fluid mobility of CO₂, methane, hydrogen and hydrocarbons through sandstones and carbonates.

Over the last decade, there has been an irreversible shift from hydrocarbon exploration towards carbon storage, low-carbon energy generation and hydrogen exploration. Whilst basin modelling techniques may be used to predict the migration of hydrocarbons through sedimentary basins on geological timescales, there remains little understanding of how fluids behave at the basin scale on present-day timescales. We apply the Darcy flow equation to present an algorithm to determine the basin-scale mobilities and maximum vertical velocity, [Formula: see text], of CO[Formula: see text], methane, hydrogen and hydrocarbons with depth for sandstone and carbonate. [Formula: see text] for CO[Formula: see text] and methane are on scales of m/year, whilst values for hydrocarbon fluids are an order of magnitude smaller than for other fluids. Our results indicate that the fluid mobility of subsurface CO[Formula: see text] may be sensitive to surface and near-surface temperature variations. [Formula: see text] for hydrogen is approximately 2-10 times greater than hydrocarbon fluids, yielding important consequences for the future use of basin modelling software for determining hydrogen migration for exploration and storage

Adaptive Calibration for Prediction of Finite Population Totals

Sample weights can be calibrated to reflect the known population totals of a set of auxiliary variables. Predictors of finite population totals calculated using these weights have low bias if these variables are related to the variable of interest, but can have high variance if too many auxiliary variables are used. This article develops an adaptive calibration approach, where the auxiliary variables to be used in weighting are selected using sample data. Adaptively calibrated estimators are shown to have lower mean squared error and better coverage properties than non-adaptive estimators in many cases