4,213 research outputs found
Pressure and convective heat-transfer measure- ments in a shock tunnel using several test gases
Pressure and convective heat-transfer measurements on hemisphere-cylinder, blunted 30 degree cone, in shock tunnel using several test gase
Search, Moral Hazard, and Price Dispersion
We study the effects of insurance coverage on consumer search behavior and the pricing of services covered by insurance, constructing a general equilibrium model of moral hazard in search with an endogenous price distribution. When an insured event occurs, households request quotes from firms, who offer a homogenous service at various prices. We show that lower coinsurance rates reduce the amount of search by households, allowing firms to increase their prices. Hence, moral hazard in search is far more costly than shown in previous models, which ignored equilibrium firm response to changes in consumer search behavior.
Study of onboard expert systems to augment space shuttle and space station autonomy
The feasibility of onboard crew activity planning was examined. The use of expert systems technology to aid crewmembers in locating stowed equipment was also investigated. The crew activity planning problem, along with a summary of past and current research efforts, was discussed in detail. The requirements and specifications used to develop the crew activity planning system was also defined. The guidelines used to create, develop, and operate the MFIVE Crew Scheduler and Logistics Clerk were discussed. Also discussed is the mathematical algorithm, used by the MFIVE Scheduler, which was developed to aid in optimal crew activity planning
Space Applications of Automation, Robotics and Machine Intelligence Systems (ARAMIS), phase 2. Volume 1: Telepresence technology base development
The field of telepresence is defined, and overviews of those capabilities that are now available, and those that will be required to support a NASA telepresence effort are provided. Investigation of NASA's plans and goals with regard to telepresence, extensive literature search for materials relating to relevant technologies, a description of these technologies and their state of the art, and projections for advances in these technologies over the next decade are included. Several space projects are examined in detail to determine what capabilities are required of a telepresence system in order to accomplish various tasks, such as servicing and assembly. The key operational and technological areas are identified, conclusions and recommendations are made for further research, and an example developmental program is presented, leading to an operational telepresence servicer
Space applications of Automation, Robotics And Machine Intelligence Systems (ARAMIS). Volume 3, phase 2: Executive summary
The field of telepresence is defined, and overviews of those capabilities that are now available, and those that will be required to support a NASA telepresence effort are provided. Investigation of NASA's plans and goals with regard to telepresence, extensive literature search for materials relating to relevant technologies, a description of these technologies and their state of the art, and projections for advances in these technologies are included. Several space projects are examined in detail to determine what capabilities are required of a telepresence system in order to accomplish various tasks, such as servicing and assembly. The key operational and technological areas are identified, conclusions and recommendations are made for further research, and an example developmental program leading to an operational telepresence servicer is presented
Space Applications of Automation, Robotics and Machine Intelligence Systems (ARAMIS), phase 2. Volume 2: Telepresence project applications
The field of telepresence is defined and overviews of those capabilities that are now available, and those that will be required to support a NASA telepresence effort are provided. Investigation of NASA' plans and goals with regard to telepresence, extensive literature search for materials relating to relevant technologies, a description of these technologies and their state of the art, and projections for advances in these technologies over the next decade are included
The role of thermal and lubricant boundary layers in the transient thermal analysis of spur gears
An improved convection heat-transfer model has been developed for the prediction of the transient tooth surface temperature of spur gears. The dissipative quality of the lubricating fluid is shown to be limited to the capacity extent of the thermal boundary layer. This phenomenon can be of significance in the determination of the thermal limit of gears accelerating to the point where gear scoring occurs. Steady-state temperature prediction is improved considerably through the use of a variable integration time step that substantially reduces computer time. Computer-generated plots of temperature contours enable the user to animate the propagation of the thermal wave as the gears come into and out of contact, thus contributing to better understanding of this complex problem. This model has a much better capability at predicting gear-tooth temperatures than previous models
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