15,492 research outputs found
General Fast Sampling Theorems for Nonlinear Systems
This paper is concerned with the gap metric approach to controller discretisation problems for continuous-time nonlinear systems with disturbances in both input and output channels. The principal idea is to construct a discrete controller based on a given stabilizing continuous time controller via a fast sampling and hold procedure and to calculate the gap between the two controllers. It is expected that, under general conditions, the computed gap depends on the discrete sample size and the faster the sample rate, the smaller the gap and, therefore, existing gap metric robust stability theorems can be applied to obtain both stability and performance results for the appropriately discretised controller. This is shown for the case of memoryless controllers and for a more general class of controllers specified by stable, causal operators. In both cases, both regional and global results are obtained under respective local and global incremental stability assumptions on the controllers
Solar flare radiation protection requirements for passive and active shields
Solar flare radiation protection requirements for passive and active shields for manned spacecraft on interplanetary fligh
Theoretical studies on the mechanical behavior of granular materials under very low intergranular stresses
The salient aspects of the theoretical modeling of a conventional triaxial test (CTC) of a cohesionless granular medium with stress and strain rate loading are described. Included are a controllable gravitational body force and provision for low confining pressure and/or very low intergranular stress. The modeling includes rational, analytic, and numerical phases, all in various stages of development. The numerical evolutions of theoretical models will be used in final design stages and in the analysis of the experimental data. In this the experimental design stage, it is of special interest to include in the candidate considerations every anomaly found in preliminary terrestrial experimentation. Most of the anomalies will be eliminated by design or enhanced for measurement as the project progresses. The main aspect of design being not the physical apparatus but the type and trajectories of loading elected. The major considerations that have been treated are: appearance and growth of local surface aberrations, stress-power coefficients, strain types, optical strain, radial bead migration, and measures of rotation for the proper stress flux
Expert system verification and validation study. ES V/V guidelines/workshop conference summary
The intent of the workshop was to start moving research on the verification and validation (V&V) of knowledge based systems (KBSs) in the direction of providing tangible 'products' that a KBS developer could use. In the near term research will focus on identifying the kinds of experiences encountered during KBS development of 'real' KBSs. These will be stored in a repository and will serve as the foundation for the rest of the activities described here. One specific approach to be pursued is 'benchmarking'. With this approach, a KBS developer can use either 'canned' KBSs with seeded errors or existing KBSs with known errors to evaluate a given tool's ability to satisfactorily identify errors
Ectoparasites and Other Arthropod Associates of the Hairy-tailed Mole, \u3ci\u3eParascalops Breweri\u3c/i\u3e
A total of 33 taxa of ectoparasites and other associates was taken on seven individuals of the Hairy-tailed Mole, Parascalops breweri, from New York and New England. The most abundant form was the glycyphagid mite, Labidophorus nearcticus
Ectoparasites and Other Arthropod Associates of Some Voles and Shrews From the Catskill Mountains of New York
Reported here from the Catskill Mountains of New York are 30 ectoparasites and other associates from 39 smoky shrews, Sorex fumeus, 17 from 11 masked shrews, Sorex cinereus, 11 from eight long-tailed shrews, Sorex dispar, and 31 from 44 rock voles, Microtus chrotorrhinus
Buoyant Venus station mission feasibility study for 1972 and 1973 launch opportunities. Volume 2 - Trajectory analysis for 1972 and 1973 missions Final report
Trajectory analysis for 1972 and 1973 buoyant Venus station missio
Neurophysiological and Behavioral Studies of Chimpanzees Semiannual Report, 1 Jul. - 31 Dec. 1966
Computer program for control of chimpanzee discrimination test analysis and electroencephalographic response dat
The plasma radiation shield - Concept, and applications to space vehicles
Plasma radiation shield - concept and applications to space vehicle
Monitoring brain function and performance in the primate under prolonged weightlessness Final report, 15 Aug. 1963 - 14 Aug. 1964
Summary of program for monitoring brain function and performance in primate under prolonged weightlessnes
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