3,765 research outputs found

    Decision-making and problem-solving methods in automation technology

    Get PDF
    The state of the art in the automation of decision making and problem solving is reviewed. The information upon which the report is based was derived from literature searches, visits to university and government laboratories performing basic research in the area, and a 1980 Langley Research Center sponsored conferences on the subject. It is the contention of the authors that the technology in this area is being generated by research primarily in the three disciplines of Artificial Intelligence, Control Theory, and Operations Research. Under the assumption that the state of the art in decision making and problem solving is reflected in the problems being solved, specific problems and methods of their solution are often discussed to elucidate particular aspects of the subject. Synopses of the following major topic areas comprise most of the report: (1) detection and recognition; (2) planning; and scheduling; (3) learning; (4) theorem proving; (5) distributed systems; (6) knowledge bases; (7) search; (8) heuristics; and (9) evolutionary programming

    Conference on Automated Decision-Making and Problem Solving, the Third Day: Issues Discussed

    Get PDF
    A conference held at Langley Research Center in May of 1980 brought together university experts from the fields of Control Theory, Operations Research, and Artificial Intelligence to explore current research in automation from both the perspective of their own particular disciplines and from that of interdisciplinary considerations. Informal discussions from the final day of the those day conference are summarized

    Systems simulations supporting NASA telerobotics

    Get PDF
    Two simulation and analysis environments have been developed to support telerobotics research at the Langley Research Center. One is a high-fidelity, nonreal-time, interactive model called ROBSIM, which combines user-generated models of workspace environment, robots, and loads into a working system and simulates the interaction among the system components. Models include user-specified actuator, sensor, and control parameters, as well as kinematic and dynamic characteristics. Kinematic, dynamic, and response analyses can be selected, with system configuration, task trajectories, and arm states displayed using computer graphics. The second environment is a real-time, manned Telerobotic Systems Simulation (TRSS) which uses the facilities of the Intelligent Systems Research Laboratory (ISRL). It utilizes a hierarchical structure of functionally distributed computers communicating over both parallel and high-speed serial data paths to enable studies of advanced telerobotic systems. Multiple processes perform motion planning, operator communications, forward and inverse kinematics, control/sensor fusion, and I/O processing while communicating via common memory. Both ROBSIM and TRSS, including their capability, status, and future plans are discussed. Also described is the architecture of ISRL and recent telerobotic system studies in ISRL

    Credit Rationing in the U.S. Mortgage Market: Evidence from Variation in FHA Market Shares

    Get PDF
    This paper examines the nature of mortgage credit rationing across geographic markets and time. Particular attention is paid to the response of conventional mortgage supply to higher risk conditions associated with regional recessions. We develop a series of four indirect tests based on the spatial variation of the FHA share of mortgages, both endorsements and applications, as well as FHA and conventional rejection rates. Results of these four tests indicate that conventional mortgage underwriting criteria do not become more flexible and may even become more demanding when local economic conditions deteriorate. This result indicates the use of non-price credit rationing in the mortgage market and suggests a special role for FHA-insured mortgages as a mechanism for maintaining mortgage credit supply in declining housing markets

    Interpreting the environmental record in the sediments of Blelham Tarn

    Get PDF
    Two aspects of the environmental record in the sediments of Blelham Tarn have been investigated: (1) the ecological history of the catchment, and lake-catchment relationships, by detailed analysis of the preserved pollen (as an indication of vegetation) and sediment composition with respect to a range of inorganic and organic geochemical variables and (2) a detailed investigation of the manner in which sediment is being formed today, including the way in which microfossils (pollen and diatoms) are being recruited and incorporated into sediments. When the record was examined by biological and geochemical analysis, together with radionuclide dating, of closely spaced samples, it was found that the changes of the last 30 yrs represented only the most recent episode in a long history of modification of the lake by man. To find an approach to this it is necessary to go back for at least 2500 yrs

    Human activity was a major driver of the mid-Holocene vegetation change in southern Cumbria: Implications for the elm decline in the British Isles

    Get PDF
    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The dramatic decline in elm (Ulmus) across a large swathe of north-west Europe in the mid-Holocene has been ascribed to a number of possible factors, including climate change, human activity and/or pathogens. A major limitation for identifying the underlying cause(s) has been the limited number of high-resolution records with robust geochronological frameworks. Here, we report a multiproxy study of an upland (Blea Tarn) and lowland (Urswick Tarn) landscape in southern Cumbria (British Isles) to reconstruct vegetation change across the elm decline in an area with a rich and well-dated archaeological record to disentangle different possible controls. Here we find a two-stage decline in Ulmus taking place between 6350–6150 and 6050–5850 cal a BP, with the second phase coinciding with an intensification of human activity. The scale of the decline and associated human impact is more abrupt in the upland landscape. We consider it likely that a combination of human impact and disease drove the Ulmus decline within southern Cumbria.This work was funded by a studentship for MJG from the University of Exeter and Sir John Fisher Foundation. Additional funding for 14C dating was from the Cumberland and Westmorland Antiquarian and Archaeological Society (Clare Fell Bursary to MJG), and the Australian Research Council (FL100100195)

    Research and education in management of large- scale technical programs Semiannual progress report

    Get PDF
    Research and education in management of large scale technical programs - education and integration of interdisciplinary tea

    The preparation, identification and properties of chlorophyll derivatives

    Get PDF
    In the investigation of 10-hydroxy chlorophylls a and b novel techniques included modification of chromatography and the use of fully-deuterated compounds isolated from fully-deuterated autotropic algae to determine the molecular structure of the chlorophylls

    Cerebral Palsy: Enhancing Movement Opportunity with Help from the Care Team

    Get PDF
    Cerebral palsy is the most common motor disability in childhood. Cerebral palsy can significantly impact the amount of physical activity and individual obtains, and the scope and quality of the physical activity may be limited by cerebral palsy. High-quality physical education can integrate children with cerebral palsy into movement programing, as to enable children with cerebral palsy to achieve goals related to cognitive skills associated with exploring physical health, maintaining physical health, as well as affective values towards physical health, movement, play, and general wellbeing. This article provides a basic overview of the physical characteristics of cerebral palsy, as well as outlines ways the child’s educational care-team can work with physical educators and physical therapist to enhance movement skills and health behavior
    • …
    corecore