9,280 research outputs found
Physical insight into the simultaneous optimization of structure and control
Recent trends in spacecraft design which yield larger structures with more stringent performance requirements place many flexible modes of the structure within the bandwidth of active controllers. The resulting complications to the spacecraft design make it highly desirable to understand the impact of structural changes on an optimally controlled structure. This work uses low structural models with optimal H(sub 2) and H(sub infinity) controllers to develop some basic insight into this problem. This insight concentrates on several basic approaches to improving controlled performance and how these approaches interact in determining the optimal designs. A numerical example is presented to demonstrate how this insight can be generalized to more complex problems
Origins of Congenital Defects: Epidemiologic Approach
This presentation consists of several short stories from personal experience to illustrate the complementary nature of epidemiologic and laboratory research in the study of congenital malformations
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