568 research outputs found

    Study of aircraft in intraurban transportation systems, volume 1

    Get PDF
    An analysis of an effective short range, high density computer transportation system for intraurban systems is presented. The seven county Detroit, Michigan, metropolitan area, was chosen as the scenario for the analysis. The study consisted of an analysis and forecast of the Detroit market through 1985, a parametric analysis of appropriate short haul aircraft concepts and associated ground systems, and a preliminary overall economic analysis of a simplified total system designed to evaluate the candidate vehicles and select the most promising VTOL and STOL aircraft. Data are also included on the impact of advanced technology on the system, the sensitivity of mission performance to changes in aircraft characteristics and system operations, and identification of key problem areas that may be improved by additional research. The approach, logic, and computer models used are adaptable to other intraurban or interurban areas

    Advanced techniques for high resolution spectroscopic observations of cosmic gamma-ray sources

    Get PDF
    An advanced gamma-ray spectrometer that is currently in development is described. It will obtain a sensitivity of 0.0001 ph/sq cm./sec in a 6 hour balloon observation and uses innovative techniques for background reduction and source imaging

    Structural Change in (Economic) Time Series

    Get PDF
    Methods for detecting structural changes, or change points, in time series data are widely used in many fields of science and engineering. This chapter sketches some basic methods for the analysis of structural changes in time series data. The exposition is confined to retrospective methods for univariate time series. Several recent methods for dating structural changes are compared using a time series of oil prices spanning more than 60 years. The methods broadly agree for the first part of the series up to the mid-1980s, for which changes are associated with major historical events, but provide somewhat different solutions thereafter, reflecting a gradual increase in oil prices that is not well described by a step function. As a further illustration, 1990s data on the volatility of the Hang Seng stock market index are reanalyzed.Comment: 12 pages, 6 figure

    The BATSE experiment on the Gamma Ray Observatory: Solar flare hard x ray and gamma-ray capabilities

    Get PDF
    The Burst and Transient Source Experiment (BATSE) for the Gamma Ray Observatory (GRO) consists of eight detector modules that provide full-sky coverage for gamma-ray bursts and other transient phenomena such as solar flares. Each detector module has a thin, large-area scintillation detector (2025 sq cm) for high time-resolution studies, and a thicker spectroscopy detector (125 sq cm) to extend the energy range and provide better spectral resolution. The total energy range of the system is 15 keV to 100 MeV. These 16 detectors and the associated onboard data system should provide unprecedented capabilities for observing rapid spectral changes and gamma-ray lines from solar flares. The presence of a solar flare can be detected in real-time by BATSE; a trigger signal is sent to two other experiments on the GRO. The launch of the GRO is scheduled for June 1990, so that BATSE can be an important component of the Max '91 campaign

    Historical and Projected Municipal and Industrial Water Usage in Utah 1960-2020

    Get PDF
    This publication reports the results of a municipal and industrial water use inventory. Data reported covers the period 1960 through 1976. Time series information is aggregated from municipal and industrial system level to country and state totals. Total municipal and industrial withdrawals are divided between surface and groundwater sources. Yearly per capital withdrawal rates are estimated for 50 Utah municipalities and for each of Utah’s 29 counties. Per capita withdrawal rates range from a high of over 400 gallons per capita per day (gcd) in the communities of Delta, Fillmore, Hyrum, Logan, and Morgan to a low of 100 gcd in Bountiful, Washington, Terrace, Centerville, and South Ogden. A three year average (1974, 1975, and 1976) of Utah’s per capita withdrawal rate is 262 gcd. Also reported are return flow rates for 13 Utah waste treatment facilities. Withdrawal and return flow rates are also reported for Utah’s major water using industries. These rates are reported in gallons per employee per day (or gallons per unit of output). The publication also discusses methodologies for projecting municipal and industrial usage in Utah to the year 2020. Also reported are population projections for multicounty districts, counties and major cities by ten year intervals from 1960-2020

    Definition of remission and relapse in polymyalgia rheumatica: data from a literature search compared with a Delphi-based expert consensus

    Get PDF
    OBJECTIVE: To compare current definitions of remission and relapse in polymyalgia rheumatica (PMR) with items resulting from a Delphi-based expert consensus. METHODS: Relevant studies including definitions of PMR remission and relapse were identified by literature search in PubMed. The questionnaire used for the Delphi survey included clinical (n=33), laboratory (n=54) and imaging (n=7) parameters retrieved from a literature search. Each item was assessed for importance and availability/practicability, and limits were considered for metric parameters. Consensus was defined by an agreement rate of ≥80%. RESULTS: Out of 6031 articles screened, definitions of PMR remission and relapse were available in 18 and 34 studies, respectively. Parameters used to define remission and/or relapse included history and clinical assessment of pain and synovitis, constitutional symptoms, morning stiffness (MS), physician's global assessment, headache, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), blood count, fibrinogen and/or corticosteroid therapy. In the Delphi exercise a consensus was obtained on the following parameters deemed essential for definitions of remission and relapse: patient's pain assessment, MS, ESR, CRP, shoulder and hip pain on clinical examination, limitation of upper limb elevation, and assessment of corticosteroid dose required to control symptoms. CONCLUSIONS: Assessment of patient's pain, MS, ESR, CRP, shoulder pain/limitation on clinical examination and corticosteroid dose are considered to be important in current available definitions of PMR remission and relapse and the present expert consensus. The high relevance of clinical assessment of hips was unique to this study and may improve specificity and sensitivity of definitions for remission and relapse in PMR
    corecore