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Reutilization of software is a difficult goal to achieve particularly in complex environments that require advanced software systems. The Request-Oriented Scheduling Engine (ROSE) was developed to create a reusable scheduling system for the diverse scheduling needs of the National Aeronautics and Space Administration (NASA). ROSE is a data-driven scheduler that accepts inputs such as user activities, available resources, timing contraints, and user-defined events, and then produces a conflict-free schedule. To support reutilization, ROSE is designed to be flexible, extensible, and portable. With these design features, applying ROSE to a new scheduling application does not require changing the core scheduling engine, even if the new application requires significantly larger or smaller data sets, customized scheduling algorithms, or software portability. This paper includes a ROSE scheduling system description emphasizing its general-purpose features, reutilization techniques, and tasks for which ROSE reuse provided a low-risk solution with significant cost savings and reduced software development time.

Recent numerical studies of convection in the earth's mantle have included various features of plate tectonics. This paper describes three methods of modeling plates: through material properties, through force balance, and through a thin power-law sheet approximation. The results obtained are compared using each method on a series of simple calculations. From these results, scaling relations between the different parameterizations are developed. While each method produces different degrees of deformation within the surface plate, the surface heat flux and average plate velocity agree to within a few percent. The main results are not dependent upon the plate modeling method and herefore are representative of the physical system modeled.

Mission planning and scheduling of spacecraft operations are becoming more complex at NASA. Described here are a mission planning process; a robust, flexible planning language for spacecraft and payload operations; and a software scheduling system that generates schedules based on planning language inputs. The mission planning process often involves many people and organizations. Consequently, a planning language is needed to facilitate communication, to provide a standard interface, and to represent flexible requirements. The software scheduling system interprets the planning language and uses the resource, time duration, constraint, and alternative plan flexibilities to resolve scheduling conflicts.

The following topics are presented in view graph form and include the following: scheduling application; the motivation for the Flexible Envelope Request Notation (FERN); characteristics of FERN; types of information needed in requests; where information is stored in requests; FERN structures; generic requests; resource availability for pooled resources; expressive notation; temporal constraints; time formats; changes to FERN; sample FERN requests; the temporal relationship between two steps; maximum activity length to limit step delays; alternative requests; the temporal relationship between two activities; and idle resource usage between steps.

A study was conducted in a day care setting to assess whether differences in the intellectual and social competence scores of young children were reflected in the communicative behavior occurring between the children's mothers and caregivers. A total of forty-seven 2- to 4-year-old children in day care and their mothers participated. Two instruments developed by the researcher measured mothers' attitudes and behaviors. Additionally, the McCarthy Scales of Children's Abilities and the Harvard Preschool Project's Social Competence Checklist were administered to test, respectively, children's intellectual and social competence. Based on the sample, it was determined that, as children scored higher on intellectual and social tests, their mothers were found to be making increased efforts to become knowledgeable consumers of day care services for their children. Specifically, significant relationships were found (1) between mothers' communicative attitude scores and their children's intellectual and social competence scores and (2) between mothers' communicative attitude scores and their communicative behavior. Results suggested that the mother/caregiver interaction is highly attitudinal. Appended are two checklists (Classification of Parent Attitude toward Caregiver Communication and Parent Participation Communication Checklist) and two charts (Attitude toward Caregiver Communication and Levels of Communicative Behavior). (Author/BJD)

Users of instructional innovations in civilian and military instructional settings were compared in factors that influence the adoption of new technologies for their respective learning environments. Administrators and instructors from Florida public school systems and the U.S. Marine Corps participated in qualitative, quantitative, and attitudinal surveys to measure their adoption behavior. A survey instrument and followup interviews measured Florida teachers' attitudes toward instructional television (ITV). Survey instruments and onsite interviews collected data from Marines. Instruments measured the quantity and quality of Training and Audiovisual Support System (TAVSS) operations and Marines' attitudes toward TAVSS policies and practices. Rogers and Shoemaker's "perceived attributes of innovations and their rate of adoption" were correlated with the quality and quantity of use and attitudes toward instructional innovations. When compared, the two groups showed the same types of adoption concerns. The quantity, quality, and attitude results were influenced by the degree to which the potential adopter of a technological innovation perceived it to be relatively advantageous to existing instructional products and procedures, compatible with the curriculum or training program, available for short-term tryout, instructionally measurable by observation and data, and free from unnecessary complexity. (Author/YLB)

An analysis of four different hotspot distributions, ranging from Morgan's (1972) original list of 19 to Vogt's (1981) list of 117 reveals that the hotspots are preferentially located near divergent plate boundaries. The probability of this proximity occurring by chance alone is quite remote, less than 0.01 for all four hotspot distributions. The same analysis also reveals that the hotspots are preferentially excluded from regions near convergent plate boundaries. The probability of this exclusion occurring by chance alone is 0.1 or less for three out of the four distributions examined. We interpret this behavior as being a consequence of the effects of large scale convective circulation on ascending mantle plumes. Mantle thermal plumes, the most probable source of hotspots, arise from instabilities in a basal thermal boundary layer. Plumes are suppressed from regions beneath convergent boundaries by descending flow and are entrained into the upwelling flow beneath spreading centers. Plate-scale convective circulation driven by subduction may also advect mantle thermal plumes toward spreading centers.