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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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This paper describes a real life case study for a web based prototype design environment to support the generation and documentation of mission concepts that will result in mission proposals to NASA.
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In this paper we describe design centers and show how it has produced remarkable decreases in time and expense of creating preliminary designs.
This paper describes the new process used by the Project Design Center at NASA's Jet Propulsion Laboratory for the identification, assessment and communication of risk elements throughout the lifecycle of a mission design. This process includes a software tool, 'RAP' that collects and communicates risk information between the various designers and a 'risk expert' who mediates this process. The establishment of this process is an attempt towards the systematic consideration of risk in the design decision making process. Using this process, we are able to better keep track of the risks associated with the design decisions. Furthermore, it helps us develop better risk profiles for the studies under consideration. We aim to refine and expand the current process to enable more thorough risk analysis capabilities in the future.
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Task Space control of manipulators is extended both in the number of simultaneous behaviors and in the dimension of task space. An application is decomposed into multiple simultaneous behaviors whose resultant behavior will provide the motion necessary to execute the task. Each behavior generates commands in its own coordinate system. These simultaneous commands are merged in a motion space using impedance control to complete a resultant command to the manipulator. The task space of each behavior can have the dimensionality of the mechanism being controlled. Control of a seven degree of freedom manipulator is described here so the available task space for each behavior has dimensionality seven.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Direct frequency comparison of atomic hydrogen masers in different places and conditions by simultaneous monitoring of Loran C signals
Human information processing rates on one and two axis compsensatory tracking tasks with secondary auditory task
Human information processing rates during one and two axis compensatory tracking tasks with secondary auditory task
Kinetic analysis of ion-molecule reactions in Ar-N mixtures with H, deuterium and HD using ion ejection mode of ion-cyclotron- resonance spectroscopy
The yes-no signal detection procedure was applied to a single-response operant paradigm in which rats discriminated between a standard auditory intensity and attenuated comparison values. The payoff matrix was symmetrical (with reinforcing brain stimulation for correct detections and brief time-out for errors), but signal probability and intensity differences were varied to generate a family of isobias and isosensitivity functions. The d' parameter remained fairly constant across a wide range of bias levels. Isobias functions deviated from a strict matching strategy as discrimination difficulty increased, although an orderly relation was maintained between signal probability value and the degree and direction of response bias.