1,376 research outputs found

    Fundamental study in low-density gas dynamics Progress report, 1 Nov. 1968 - 30 Jun. 1969

    Get PDF
    Theoretical and experimental study of rarefied gas viscoseals in continuum to free molecular density range and speeds up to 30,000 rp

    Tunable lasers for water vapor measurements and other lidar applications

    Get PDF
    A tunable dye laser suitable for differential absorption (DIAL) measurements of water vapor in the troposphere was constructed. A multi-pass absorption cell for calibration was also constructed for use in atmospheric DIAL measurements of water vapor

    Development of an Expert System to Convert Knowledge-based Geological Engineering Systems into Fortran

    Get PDF
    A knowledge-based geographic information system (KBGIS) for geological engineering map (GEM) production was developed in GoldWorks, an expert system development shell. GoldWorks allows the geological engineer to develop a rule base for a GEM application. Implementation of the resultant rule base produced a valid GEM, but took too much time. This proved that knowledge-based GEM production was possible but in GoldWorks implementation failed as a practical production system. To solve this problem, a Conversion Expert System was developed which accepted, as input, a KBGIS and produced, as output, the equivalent Fortran code. This allowed the engineer to utilize GoldWorks for development of the rule base while implementing the rule base in a more practical manner (as a Fortran program). Testing of the Fortran program generated by this Conversion System confirmed that the GEMs produced were identical to those from the KBGIS, and execution time was significantly reduced. There was an additional benefit; since use of the Fortran program did not require access to the GoldWorks System, a single GoldWorks package could be used with the Conversion System to develop several Fortran production systems. These systems could then be used at remote production sites. However, each Fortran production system still required access to the Earth Resources Data Analysis System (ERDAS) that supplied the GIS input and output files. Thus, this Conversion System achieved two major objectives; it dramatically reduced GEM production time, and it added versatility

    An Expert System to Convert Knowledge-Based Geological Engineering Systems into Fortran

    Get PDF
    A knowledge-based geographic information system (KBGIS) for geological engineering map (GEM) production was developed in GoldWorks, an expert system development shell. Using this shell, the geological engineer is able to develop a rule base for a particular application that results in a valid GEM. However, this implementation failed as a practical production system due to the excessive execution time required to produce a GEM. To solve this problem, a conversion expert system was developed which accepted, as input, a KBGIS and produced, as output, the equivalent Fortran code. Two major objectives are accomplished as a result of this system: GEN production time is dramatically reduced and the versatility of the KBGIS development environment is retained. The conversion expert system was tested by converting the Midwestern KBGIS expert syste

    Experimentation with Proof Methods for Non-Horn Sets

    Get PDF
    Two Resolution Proof Strategies Developed by Peterson Are Implemented by Modifying Otter, an Existing Automated Theorem Prover. the Methods, Lock-T Refutation and LNL-T Refutation, Are Generalizations of Unit Refutation and Input Resolution, Respectively, to Non-Horn Sets and Represent Independent, Equivalent but Opposite Ways of Searching. the Algorithms Used Are based on a Corrected Version of the Foundational Work. the Strategies Have Been Tested on Various Non-Horn Challenge Problems from the Tarskian Geometry and the Non-Obvious Problem, with the Results Being in Some Cases Quite Favorable When Compared to Other Resolution Techniques

    Application of Remote Sensing to the Chesapeake Bay Region. Volume 2: Proceedings

    Get PDF
    A conference was held on the application of remote sensing to the Chesapeake Bay region. Copies of the papers, resource contributions, panel discussions, and reports of the working groups are presented

    Application of Remote Sensing to the Chesapeake Bay Region. Volume 1: Executive summary

    Get PDF
    The proceedings are presented of a conference, jointly sponsored by the National Aeronautics and Space Administration, the U.S. Environmental Protection Agency, and the University of Maryland. The purpose of the Conference was to assemble representatives of federal and state government agencies engaged in research on the condition and evolution of the Chesapeake Bay to compose a status report, to present current activities and future plans, and to recommend a long-range future course of policies and programs

    A pulsed, mono-energetic and angular-selective UV photo-electron source for the commissioning of the KATRIN experiment

    Get PDF
    The KATRIN experiment aims to determine the neutrino mass scale with a sensitivity of 200 meV/c^2 (90% C.L.) by a precision measurement of the shape of the tritium β\beta-spectrum in the endpoint region. The energy analysis of the decay electrons is achieved by a MAC-E filter spectrometer. To determine the transmission properties of the KATRIN main spectrometer, a mono-energetic and angular-selective electron source has been developed. In preparation for the second commissioning phase of the main spectrometer, a measurement phase was carried out at the KATRIN monitor spectrometer where the device was operated in a MAC-E filter setup for testing. The results of these measurements are compared with simulations using the particle-tracking software "Kassiopeia", which was developed in the KATRIN collaboration over recent years.Comment: 19 pages, 16 figures, submitted to European Physical Journal

    Observed Coupling of the Mesosphere Inversion Layer to the Thermal Tidal Structure

    Get PDF
    Rayleigh lidar observations of mesosphere temperature profiles obtained from 40 to ∼100 km from Logan, Utah (41.7, 111.8 W, altitude, 1.9 km) over 10 nights in late February, 1995, revealed an interesting development between 60 to 75 km of a winter mesosphere inversion layer with an amplitude of ∼20–30 K and a downward phase progression of ∼1 km/hr. The data also showed two altitude regions exhibiting significant cooling of 10–30 K in extent. These were located below and above the peak of the inversion layer, respectively, at altitudes of ∼50–55 km and ∼70–80 km. When these results were compared with the predictions of a global wave scale model (GSWM), the observed thermal mesosphere structure is similar to the computed composite tidal structure based upon the semi‐diurnal and diurnal tides with the exception that observed amplitudes of heating and cooling are ∼10x larger than predicted GSWM values. We suggest that these events over Utah are caused through a localized mechanism involving the coupling of gravity waves to the mesopause tidal structure
    corecore