CS 801: Advanced Database Systems

Introduction of current trends and research issues in database systems

CS 701: Database Systems and Design

Introduction of DB design concepts and operating principles of database systems

CS 7700: Advanced Database Systems

Introduction of DB design concepts and operating principles of database systems

CS 405/605: Introduction to Database Management Systems

Survey of logical and physical aspects of database management systems. Entity Relationship, relational, object-oriented models for databases are presented. Physical implementation methods are discussed

CS 801: Advanced Database Systems

Introduction of current trends and research issues in database systems

CEG 820-01: Computer Architecture II

Continuation of CEG 720 with more details on multiprocessor systems, parallel processing, and performance analysis

CS 801: Advanced Database Systems

Introduction of current trends and research issues in database systems

CEG 820-01: Computer Architecture II

Continuation of CEG720 with more details on multiprocessor systems, parallel processing, and performance analysis

SPHERES Tethered Formation Flight Testbed: Application to NASA’s SPECS Mission

This paper elaborates on theory and experiment of the formation flight control for the future space-borne tethered interferometers. The nonlinear equations of multi-vehicle tethered spacecraft system are derived by Lagrange equations and decoupling method. The preliminary analysis predicts unstable dynamics depending on the direction of the tether motor. The controllability analysis indicates that both array resizing and spin-up are fully controllable only by the reaction wheels and the tether motor, thereby eliminating the need for thrusters. Linear and nonlinear decentralized control techniques have been implemented into the tethered SPHERES testbed, and tested at the NASA MSFC's flat floor facility using two and three SPHERES configurations. The nonlinear control using feedback linearization technique performed successfully in both two SPHERES in-line configuration and three triangular configuration while varying the tether length. The relative metrology system, using the ultra sound metrology system and the inertial sensors as well as the decentralized nonlinear estimator, is developed to provide necessary state information

On Development of 100-Gram-Class Spacecraft for Swarm Applications

A novel space system architecture is proposed, which would enable 100-g-class spacecraft to be flown as swarms (100 s-1000 s) in low Earth orbit. Swarms of Silicon Wafer Integrated Femtosatellites (SWIFT) present a paradigm-shifting approach to distributed spacecraft development, missions, and applications. Potential applications of SWIFT swarms include sparse aperture arrays and distributed sensor networks. New swarm array configurations are introduced and shown to achieve the effective sparse aperture driven from optical performance metrics. A system cost analysis based on this comparison justifies deploying a large number of femtosatellites for sparse aperture applications. Moreover, this paper discusses promising guidance, control, and navigation methods for swarms of femtosatellites equipped with modest sensing and control capabilities