Computer Sciences Corporation

About: Computer Sciences Corporation is a based out in . It is known for research contribution in the topics: Spacecraft & Software development. The organization has 1916 authors who have published 2389 publications receiving 62729 citations. The organization is also known as: CSC.

Atmospheric environment for space shuttle (STS-8) launch

Abstract: Selected atmospheric conditions observed near Space Shuttle STS-8 launch time on August 30, 1983, at Kennedy Space Center, Florida are summarized. Values of ambient pressure, temperature, moisture, ground winds, visual observations (cloud), and winds aloft are included. The sequence of prelaunch Jimsphere measured vertical wind profiles is given. Also presented are wind and thermodynamic parameters representative of surface and aloft conditions in the SRB descent/impact ocean area. Final meteorological tapes, which consist of wind and thermodynamic parameters versus altitude, for STS-8 vehicle ascent and SRB descent/impact were constructed. The STS-8 ascent meteorological data tape was constructed.

A duality principle for state estimation with partially noise corrupted measurements

Abstract: In derivations of the Kalman-Bucy filter, one generally assumes that the measurement noise process possesses a nonsingular covariance matrix. Some authors, [1], [2], have derived formulas for a reduced order optimal estimator with a singular covariance matrix. Their solutions require coordinate transformations in both state and output noise variables. Here we employ the Moore-Penrose generalized inverse of the noise covariance matrix to obtain a full order optimal filter without the use of coordinate transformations. Two different optimal estimators corresponding to two different optimization criteria are found. One of these estimators provides a duality principle relating the optimal estimation problem with a partially singular optimal control problem.

NAS experiences with a prototype cluster of workstations

Abstract: This paper discusses the year-long activity at NAS to implement a large, loose cluster of workstations from the existing Silicon Graphics, Inc. (SGI) pool of systems. Issues related to establishing a loosely coupled cluster of workstations are presented. Included are steps needed to resolve system management issues intended to provided reasonable cycle recovery from these systems without disrupting the primary system users. Performance evaluation tests were run based on the NAS Parallel Benchmarks (NPB) and other codes, including OVERFLOW-PVM, a full-fledged computational fluid dynamics (CFD) application. This paper summarizes the activities related to the prototype cluster and identifies areas that need improvement, development, and research in order to make workstation clusters a viable computing environment for solving aeroscience problems. >