1,275 research outputs found

    Civil mini-RPA's for the 1980's: Avionics design considerations

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    A number of remote sensing or surveillance tasks (e.g., fire fighting, crop monitoring) in the civilian sector of our society may be performed in a cost effective manner by use of small remotely piloted aircraft (RPA). This study was conducted to determine equipment (and the associated technology) that is available, and that could be applied to the mini-RPA and to examine the potential applications of the mini-RPA with special emphasis on the wild fire surveillance mission. The operational considerations of using the mini-RPA as affected by government regulatory agencies were investigated. These led to equipment requirements (e.g., infra-red sensors) over and above those for the performance of the mission. A computer technology survey and forecast was performed. Key subsystems were identified, and a distributed microcomputer configuration, that was functionally modular, was recommended. Areas for further NASA research and development activity were also identified

    Organization and use of a Software/Hardware Avionics Research Program (SHARP)

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    The organization and use is described of the software/hardware avionics research program (SHARP) developed to duplicate the automatic portion of the STOLAND simulator system, on a general-purpose computer system (i.e., IBM 360). The program's uses are: (1) to conduct comparative evaluation studies of current and proposed airborne and ground system concepts via single run or Monte Carlo simulation techniques, and (2) to provide a software tool for efficient algorithm evaluation and development for the STOLAND avionics computer

    An Approach to the Questionnaire State in the Knowledge-Based Operations Management System

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    This paper discusses some preliminary thoughts about the development of a questionnaire for the Knowledge-based Operations Management System (KOMS) project. The questionnaire is designed to elicit information from managers, regarding the type of operating problems faced by them in terms of decisions which have to be made. This information is to be used to design the type of operating system appropriate for the case in question.The role of the questionnaire in relation to KOMS is discussed, with an account of the tasks that this stage would perform in the system. The type of information needed at each point has been lined briefly.Supported in part by the Office of Naval Research under contract 67-A-0204-007

    The General N-Location Distribution Problem

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    This paper studies the one-period, general network distribution problem with linear costs. The approach is to decompose the problem into a transportation problem that represents a stocking decision, and decoupled newsboy problems that represent the realization of demand with the usual associated holding and shortage costs. This approach leads to a characterization of optimal policies in terms of the dual of the transportation problem. Specifically, it is shown that there is a correspondence between the optimal policies and the extreme points, edges, faces etc. of the dual feasible region. This method is not directly suitable for the solution of large problems but the exact solution for small problems can be obtained. It is shown that the three location case involves 37 policies as compared to seven for the two location case. For the numerical solutions of large problems, the problem has been formulated as a linear program with column generation. This latter approach is quite robust in the sense that it is easily extended to incorporate capacity constraints and the multiproduct case. Extensions of this work are briefly discussed.Supported in part by the Office o Naval Research under contract 67-A-0204-007

    Comparison of Piezo and Ball Copper Pressure Measurements in Closed Vessel System

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    A series of Closed Vessel firings are carried out at different pressure levels in the range of 0 to 1800 kg/cm/sup 2/ covering the complete pressure range of ball copper and Marl 8 crusher gauge combination. The pressure are simultaneously measured by a piezo (tourmaline) gauge and the ball copper pressures are evaluated from the Tarage table for existing standard ball copper as required by U.K. ordnance, using suitable temperature corrections. The results indicated that the agreement between the piezo and ball copper pressures is generally very good. At the pressure levels of 600,1200 and 1800 kg/cm/sup 2/, the magnitudes of percentage deviation of ball copper pressures from piezo pressures are from 0.2 to 3.4, 2.6 to 4.2 and 2.0 to 4.6 respectively. The pressure recorded by ball coppers are found to be slightly on higher side compared to piezo pressure in nearly all the measurements

    Molecular markers for discriminating Streptococcus pyogenes and S. dysgalactiae subspecies equisimilis

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    Given the increasing aetiological importance of Streptococcus dysgalactiae subspecies equisimilis in diseases which are primarily attributed to S. pyogenes, molecular markers are essential to distinguish these species and delineate their epidemiology more precisely. Many clinical microbiology laboratories rely on agglutination reactivity and biochemical tests to distinguish them. These methods have limitations which are particularly exacerbated when isolates with mixed properties are encountered. In order to provide additional distinguishing parameters that could be used to unequivocally discriminate these two common pathogens, we assess here three molecular targets: the speB gene, intergenic region upstream of the scpG gene (IRSG) and virPCR. Of these, the former two respectively gave positive and negative results for S. pyogenes, and negative and positive results for S. dysgalactiae subsp. equisimilis. Thus, a concerted use of these nucleic acid-based methods is particularly helpful in epidemiological surveillance to accurately assess the relative contribution of these species to streptococcal infections and diseases

    Random Costs in Combinatorial Optimization

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    The random cost problem is the problem of finding the minimum in an exponentially long list of random numbers. By definition, this problem cannot be solved faster than by exhaustive search. It is shown that a classical NP-hard optimization problem, number partitioning, is essentially equivalent to the random cost problem. This explains the bad performance of heuristic approaches to the number partitioning problem and allows us to calculate the probability distributions of the optimum and sub-optimum costs.Comment: 4 pages, Revtex, 2 figures (eps), submitted to PR

    Healthcare Utilization and Costs Among High-Need and Frail Mexican American Medicare Beneficiaries

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    Objectives To examine Medicare health care spending and health services utilization among high-need population segments in older Mexican Americans, and to examine the association of frailty on health care spending and utilization. Methods Retrospective cohort study of the innovative linkage of Medicare data with the Hispanic Established Populations for the Epidemiologic Study of the Elderly (H-EPESE) were used. There were 863 participants, which contributed 1,629 person years of information. Frailty, cognition, and social risk factors were identified from the H-EPESE, and chronic conditions were identified from the Medicare file. The Cost and Use file was used to calculate four categories of Medicare spending on: hospital services, physician services, post-acute care services, and other services. Generalized estimating equations (GEE) with a log link gamma distribution and first order autoregressive, correlation matrix was used to estimate cost ratios (CR) of population segments, and GEE with a logit link binomial distribution was applied to estimate odds ratios (OR) of healthcare use. Results Participants in the major complex chronic illness segment who were also pre-frail or frail had higher total costs and utilization compared to the healthy segment. The CR for total Medicare spending was 3.05 (95% CI, 2.48–3.75). Similarly, this group had higher odds of being classified in the high-cost category 5.86 (95% CI, 3.35–10.25), nursing home care utilization 11.32 (95% CI, 3.88–33.02), hospitalizations 4.12 (95% CI, 2.88–5.90) and emergency room admissions 4.24 (95% CI, 3.04–5.91). Discussion Our findings highlight that frailty assessment is an important consideration when identifying high-need and high-cost patients
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