2,594 research outputs found
A Visual Language for Composable Simulation Scenarios
Modeling and Simulation plays an important role in how the Air Force trains and fights, Scenarios are used in simulation to give users the ability to specify entities and behaviors that should be simulated by a model: however, building and understanding scenarios can be a difficult and time-consuming process, furthermore, as composable simulations become more prominent, the need for a common descriptor for simulation scenarios has become evident. In order to reduce the complexity of creating and understanding simulation scenarios, a visual language was created, The research on visual languages presented in this thesis examines methods of visually specifying the high-level behavior of entities in scenarios and how to represent the hierarchy of the entities in scenarios. Through a study of current behavior specification techniques and the properties of mission-level simulation scenarios, Simulation Behavior Specification Diagrams (SBSD) were developed to represent the behavior of entities in scenarios, Additionally, the information visualization technique of treemaps was adapted to represent the hierarchy of entities in scenarios, After completing case studies on scenarios for the OneSAF simulation model, SBSDs and the application of treemaps to scenarios was considered successful, SBSD diagrams accurately represented the behavior of entities in the simulation scenarios and through software can be converted into code for use by simulation models, The treemap displayed the hierarchy of the entities along with information about the relative size of the entities when applied to simulation scenarios
A digital system for accurate time sector division of a spin stabilized vehicle
Digital system for accurate time sector division of spin stabilized vehicle as used on Pioneer space probe
Design, fabrication, testing and delivery of a solar collector
A two phase program encompassing the redesign and fabrication of a solar collector which is low in cost and aesthetically appealing is described. Phase one work reviewed the current collector design and developed a low-cost design based on specific design/performance/cost requirements. Throughout this phase selected collector component materials were evaluated by testing and by considering cost, installation, maintainability and durability. The resultant collector design was composed of an absorber plate, insulation, frame, cover, desiccant and sealant. In Phase two, three collector prototypes were fabricated and evaluated for both nonthermal and thermal characteristics. Tests included static load tests of covers, burst pressure tests of absorber plates, and tests for optical characteristics of selective absorber plate coatings. The three prototype collectors were shipped to Marshall Space Flight Center for use in their solar heating and cooling test facility
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