Tracking and data relay satellite fault isolation and correction using PACES: Power and attitude control expert system

The Power and Attitude Control Expert System (PACES) is an object oriented and rule based expert system which provides spacecraft engineers with assistance in isolating and correcting problems within the Power and Attitude Control Subsystems of the Tracking and Data Relay Satellites (TDRS). PACES is designed to act in a consultant role. It will not interface to telemetry data, thus preserving full operator control over spacecraft operations. The spacecraft engineer will input requested information. This information will include telemetry data, action being performed, problem characteristics, spectral characteristics, and judgments of spacecraft functioning. Questions are answered either by clicking on appropriate responses (for text), or entering numeric values. A context sensitive help facility allows access to additional information when the user has difficulty understanding a question or deciding on an answer. The major functionality of PACES is to act as a knowledge rich system which includes block diagrams, text, and graphics, linked using hypermedia techniques. This allows easy movement among pieces of the knowledge. Considerable documentation of the spacecraft Power and Attitude Control Subsystems is embedded within PACES. The development phase of TDRSS expert system technology is intended to provide NASA with the necessary expertise and capability to define requirements, evaluate proposals, and monitor the development progress of a highly competent expert system for NASA's Tracking and Data Relay Satellite Program

Happa: The New Frontier of Marginality and Disruption of Long-Static Racial Constructs

Recent reports have noted a rise in interracial marriages, which some say represents a positive change in attitudes toward race and ethnicity. However, the available data shows interracial marriages more often entail a union where one person is the member of the dominant group (e.g., White European). So, why is the percentage of marriage between non-dominants so rare? This chapter discusses whether this is a result of minority groups adopting majority attitudes toward other ethnic groups—a reflection of interethnic group conflict between ethnic groups—or just a reflection of the population and patterns of integration. Still, in its own way, this pattern may reinforce ethnic stereotypes and attitudes to the benefit of the majority group and the continued marginalization of ethnic groups