Guidance, navigation, and control subsystem equipment selection algorithm using expert system methods

Enhanced engineering tools can be obtained through the integration of expert system methodologies and existing design software. The application of these methodologies to the spacecraft design and cost model (SDCM) software provides an improved technique for the selection of hardware for unmanned spacecraft subsystem design. The knowledge engineering system (KES) expert system development tool was used to implement a smarter equipment section algorithm than that which is currently achievable through the use of a standard data base system. The guidance, navigation, and control subsystems of the SDCM software was chosen as the initial subsystem for implementation. The portions of the SDCM code which compute the selection criteria and constraints remain intact, and the expert system equipment selection algorithm is embedded within this existing code. The architecture of this new methodology is described and its implementation is reported. The project background and a brief overview of the expert system is described, and once the details of the design are characterized, an example of its implementation is demonstrated

Automated assembly of large space structures using an expert system executive

NASA LaRC has developed a unique testbed for investigating the practical problems associated with the assembly of large space structures using robotic manipulators. The testbed is an interdisciplinary effort which considers the full spectrum of assembly problems from the design of mechanisms to the development of software. This paper will describe the automated structures assembly testbed and its operation, detail the expert system executive and its development, and discuss the planned system evolution. Emphasis will be placed on the expert system development of the program executive. The executive program must be capable of directing and reliably performing complex assembly tasks with the flexibility to recover from realistic system errors. By employing an expert system, information pertaining to the operation of the system was encapsulated concisely within a knowledge base. This lead to a substantial reduction in code, increased flexibility, eased software upgrades, and realized a savings in software maintenance costs

From the Prison Track to the College Track: Pathways to Postsecondary Success for Out-of-School Youth

Many young people learn a discouraging set of lessons between the ages of 16 and 24. They come to see secondary school as irrelevant, available jobs as demeaning, and their prospects and choices as diminishing. Some continue to "drop in" to school long enough to get a diploma, but leave lacking the skills or interest to pursue further education. Others drop out of school altogether. Seen in this context, the ambitious promise implied in the federal law to "leave no child behind" will require moving expeditiously beyond the "one-size-fits-all," factory-model high school to a far richer diversity of learning environments. This paper focuses on four types of learning environments that appear to hold particular promise for vulnerable and potentially disconnected youth: reinvented high schools, secondary/postsecondary blends, education/employment blends, and extended learning opportunities beyond the school day, year, and building. The first section paints a statistical portrait of the substantial number of urban youth who could potentially benefit from these new programmatic options. The second section describes the authors' process for identifying and investigating emerging, powerful learning environments, then profiles four programs that show evidence of effectiveness. The report concludes with a discussion of the policy opportunities today for creating multiple avenues for young people to achieve to higher standards, along with four specific policy recommendations to meet this goal

The Effect of Guided and Unguided Television Viewing on Vocabulary and Comprehension of Fifth Grade Viewers

In this study, two questions were posed for examination. The first problem measured the significance in the gain scores of comprehension and vocabulary presented in a television program to students viewing a telecast with a guided purpose and to students viewing a telecast unguided. Students who watched the guided program yielded growth in both areas of comprehension and vocabulary. However, satisfactory academic growth was observed also in unguided television viewing. Secondly, differences were measured in posttest scores of comprehension and vocabulary presented in a television program between students viewing a telecast with a guided purpose and students viewing the telecast unguided. No significant difference was found between the posttest scores of the two groups

Data base architecture for instrument characteristics critical to spacecraft conceptual design

Spacecraft designs are driven by the payloads and mission requirements that they support. Many of the payload characteristics, such as mass, power requirements, communication requirements, moving parts, and so forth directly affect the choices for the spacecraft structural configuration and its subsystem design and component selection. The conceptual design process, which translates mission requirements into early spacecraft concepts, must be tolerant of frequent changes in the payload complement and resource requirements. A computer data base was designed and implemented for the purposes of containing the payload characteristics pertinent for spacecraft conceptual design, tracking the evolution of these payloads over time, and enabling the integration of the payload data with engineering analysis programs for improving the efficiency in producing spacecraft designs. In-house tools were used for constructing the data base and for performing the actual integration with an existing program for optimizing payload mass locations on the spacecraft

Development of a multivariate logistic model to predict bicycle route safety in urban areas

In response to the renewed appreciation of the benefits of bicycling to the environment and public health, public officials across the nation are working to establish new bicycle routes. During the past two decades, a number of methods have been endorsed for the selection of suitable bicycle routes. These methods are limited in that they do not explicitly address bicycle safety nor do they reflect urban conditions. The purpose of this research is to develop an objective bicycle route safety rating model based on injury severity. The model development was conducted using a logistic transformation of Jersey City\u27s bicycle crash data for the period 1997-2000. The resulting model meets a 90% confidence level by using various operational and physical factors (traffic volume, lane width, population density, highway classification, the presence of vertical. grades, one-way streets and truck routes) to predict the severity of an injury that would result from a crash that occurred at a specific location. The rating of the bicycle route\u27s safety is defined as the expected value of the predicted injury severity. This rating is founded on the premise that safe routes produce less severe accidents than unsafe routes. The contribution of this research goes beyond the model\u27s predictive capacity in comparing the safety of alternative routes. The model provides planners with an understanding, derived from objective data, of the factors that add to the route\u27s safety, the factors that reduce safety and the factors that are irrelevant. The model often confirms widely held beliefs as evidenced by the finding that highways with steep grades, truck routes and poor pavement quality create an unfavorable environment for bicyclists. Conversely, the model has found that increased volume and reduced lane width, at least in urban areas, actually reduce the likelihood of severe injury. Planners are encouraged to follow the lead of experienced bicyclists in choosing routes that travel through the urban centers as opposed to diverting bicyclists to circuitous routes on wide, low volume roads at the periphery of cities

NASA's Research in Aircraft Vulnerability Mitigation

Since its inception in 1958, the National Aeronautics and Space Administration s (NASA) role in civil aeronautics has been to develop high-risk, high-payoff technologies to meet critical national aviation challenges. Following the events of Sept. 11, 2001, NASA recognized that it now shared the responsibility for improving homeland security. The NASA Strategic Plan was modified to include requirements to enable a more secure air transportation system by investing in technologies and collaborating with other agencies, industry, and academia. NASA is conducting research to develop and advance innovative and commercially viable technologies that will reduce the vulnerability of aircraft to threats or hostile actions, and identify and inform users of potential vulnerabilities in a timely manner. Presented in this paper are research plans and preliminary status for mitigating the effects of damage due to direct attacks on civil transport aircraft. The NASA approach to mitigation includes: preventing loss of an aircraft due to a hit from man-portable air defense systems; developing fuel system technologies that prevent or minimize in-flight vulnerability to small arms or other projectiles; providing protection from electromagnetic energy attacks by detecting directed energy threats to aircraft and on/off-board systems; and minimizing the damage due to high-energy attacks (explosions and fire) by developing advanced lightweight, damage-resistant composites and structural concepts. An approach to preventing aircraft from being used as weapons of mass destruction will also be discussed

Collaborative practices with the framework of a professional learning community: elementary principals' perceptions of their role

The Director of Elementary Education, elementary principals, and elementary teachers offered information during a structured interview, surveys, and a focus group pertaining to collaboration. Within the context of this study, collaboration was defined as “a way of working with colleagues that is characterized by cooperation, mutual respect, and shared goals, involving sharing of information, coordinating actions, discussing what is working and what is not, and perpetually seeking input and feedback," (Edmondson, 2012, p. 54). This qualitative, bounded case study, conducted in a Midwestern suburban school district, provides an analysis of collaboration at the elementary school level with a focus on professional learning communities and the elementary principal's role. The purpose of this study was to discover perceptions of elementary principals' role in implementing collaborative processes through the framework of a professional learning community. Hord's (1997, 2008) framework for a professional learning community was the conceptual framework for this study. Open and axial coding were utilized throughout the qualitative data analysis process. Findings indicated prominent themes of facilitator, team builder, and strategic planner as the perceived role of the elementary principal in the implementation of collaborative practices and processes within a professional learning community. Additional findings indicated that each tenant of an effective professional learning community (Hord 1997, 2008) was equitably recognized by respondents across data collection modalities.Includes bibliographical references

An expert system executive for automated assembly of large space truss structures

Langley Research Center developed a unique test bed for investigating the practical problems associated with the assembly of large space truss structures using robotic manipulators. The test bed is the result of an interdisciplinary effort that encompasses the full spectrum of assembly problems - from the design of mechanisms to the development of software. The automated structures assembly test bed and its operation are described, the expert system executive and its development are detailed, and the planned system evolution is discussed. Emphasis is on the expert system implementation of the program executive. The executive program must direct and reliably perform complex assembly tasks with the flexibility to recover from realistic system errors. The employment of an expert system permits information that pertains to the operation of the system to be encapsulated concisely within a knowledge base. This consolidation substantially reduced code, increased flexibility, eased software upgrades, and realized a savings in software maintenance costs

The effect of a lesbian woman\u27s coming-out experience on her psychological well-being

This study was performed to provide social workers with knowledge about the psychosocial risks of a lesbian client\u27s coming-out event. A survey was administered consisting of 22 questions and the Center for Epidemiologic Studies-Depressed Mood Scale (CES-D)