Program on State Agency Remote Sensing Data Management (SARSDM)

A planning study for developing a Missouri natural resources information system (NRIS) that combines satellite-derived data and other information to assist in carrying out key state tasks was conducted. Four focal applications -- dam safety, ground water supply monitoring, municipal water supply monitoring, and Missouri River basin modeling were identified. Major contributions of the study are: (1) a systematic choice and analysis of a high priority application (water resources) for a Missouri, LANDSAT-based information system; (2) a system design and implementation plan, based on Missouri, but useful for many other states; (3) an analysis of system costs, component and personnel requirements, and scheduling; and (4) an assessment of deterrents to successful technological innovation of this type in state government, and a system management plan, based on this assessment, for overcoming these obstacles in Missouri

Alternative communication network designs for an operational Plato 4 CAI system

The cost of alternative communications networks for the dissemination of PLATO IV computer-aided instruction (CAI) was studied. Four communication techniques are compared: leased telephone lines, satellite communication, UHF TV, and low-power microwave radio. For each network design, costs per student contact hour are computed. These costs are derived as functions of student population density, a parameter which can be calculated from census data for one potential market for CAI, the public primary and secondary schools. Calculating costs in this way allows one to determine which of the four communications alternatives can serve this market least expensively for any given area in the U.S. The analysis indicates that radio distribution techniques are cost optimum over a wide range of conditions

HOUSEHOLD NUTRIENT DEMAND: USE OF CHARACTERISTICS THEORY AND A COMMON ATTRIBUTE MODEL

A characteristics model, which assumes goods generate a common set of attributes but no unique attribute, is described. The model yielded two equations which were estimated. One was a set of hedonic price equations in which the price paid for each food purchased was a function of imputed attribute prices. This set of equations was estimated at the household level. Nutrient demand equations were estimated across households. Imputed prices, income, and household characteristics including location, size, education, age distribution, and race affected nutrient demand levels.Consumer/Household Economics,

Behaviour and Perceptions of the Interlibrary Loan and Document Delivery Service Users: High Energy Physicists at CERN- a Case Study

CERN, the European Laboratory for Particle Physics, situated in Geneva, Switzerland, has a rare user population, which consists of more than 10,000 high energy physicists coming from other institutes scattered in Europe and the rest of the world. They come to CERN to share accelerators and research infrastructures and services. Therefore, the library and particularly the ILL-DD Service have a substantial number of potential users. As it is a research library, with many varied subject interests, and experiences the 'normal' budget restrictions, the CERN Library collection cannot accommodate all the documents in all of subjects potentially required. Therefore, the ILL-DD Service is performing an important task. During a one month period this year, we distributed a User Survey. Primarily this was to gauge the level of user satisfaction and to discover if the service was performing competently. Using these results along with statistics collected about the users requests, drawing on experience, and consulting published observations we have collected interesting information in this paper which portrays not only high energy physicists behaviour, but also user perceptions that may shape the future work of all ILL-DD Services

Prolongations of Geometric Overdetermined Systems

We show that a wide class of geometrically defined overdetermined semilinear partial differential equations may be explicitly prolonged to obtain closed systems. As a consequence, in the case of linear equations we extract sharp bounds on the dimension of the solution space.Comment: 22 pages. In the second version, a comparison with the classical theory of prolongations was added. In this third version more details were added concerning our construction and especially the use of Kostant's computation of Lie algebra cohomolog

Particle-in-cell simulations of electron acceleration by a simple capacitative antenna in collisionless plasma

We examine the electron acceleration by a localized electrostatic potential oscillating at high frequencies by means of particle‐in‐cell (PIC) simulations, in which we apply oscillating electric fields to two neighboring simulation cells. We derive an analytic model for the direct electron heating by the externally driven antenna electric field, and we confirm that it approximates well the electron heating obtained in the simulations. In the simulations, transient waves accelerate electrons in a sheath surrounding the antenna. This increases the Larmor radii of the electrons close to the antenna, and more electrons can reach the antenna location to interact with the externally driven fields. The resulting hot electron sheath is dense enough to support strong waves that produce high‐energy sounder‐accelerated electrons (SAEs) by their nonlinear interaction with the ambient electrons. By increasing the emission amplitudes in our simulations to values that are representative for the ones of the sounder on board the OEDIPUS C (OC) satellites, we obtain electron acceleration into the energy range which is comparable to the 20 keV energies of the SAE observed by the OC mission. The emission also triggers stable electrostatic waves oscillating at frequencies close to the first harmonic of the electron cyclotron frequency. We find this to be an encouraging first step of examining SAE generation with kinetic numerical simulation codes

A MARKETING-SYSTEM APPROACH TO REMOVING DISTRIBUTION BARRIERS CONFRONTING SMALL-VOLUME FRUIT AND VEGETABLE GROWERS

Marketing,

The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turn-offs. II. Results from 12 Galactic Clusters and OB Associations

Here we examine 12 Galactic clusters and OB associations containing Wolf-Rayet stars (W-Rs) and/or Luminous Blue Variables (LBVs), in order to assess the progentor masses of these evolved massive stars. We find that in the Milky Way, early-type WN stars evolve from stars with masses as low as 20Mo. Some early-type WN stars are found in clusters with very high turn-off masses, supporting our earlier results that the "WNE" class of W-Rs is a common stage in the evolution of stars with a wide range of mases. In contrast, the late-type WNs (particularly those of WN7 class) and the LBVs are only found in clusters with the very highest turn-off masses, suggesting that only the most massive stars evolve to these objects. An examination of the environment of the archetype LBV Eta Car reveals that this star is coeval with the rest of the Tr14/16 association, suggesting that its LBV properties is a normal consequence of evolution, and has little to do with the possibility that it is a binary.Comment: Scheduled for the Feb 2001 issue of the Astronomical Journal. Postscript version including figs from ftp://ftp.lowell.edu/pub/massey/galwr.ps.g