178 research outputs found

    Application of a hybrid generation/utility assessment heuristic to a class of scheduling problems

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    A two-stage heuristic solution approach for a class of multiobjective, n-job, 1-machine scheduling problems is described. Minimization of job-to-job interference for n jobs is sought. The first stage generates alternative schedule sequences by interchanging pairs of schedule elements. The set of alternative sequences can represent nodes of a decision tree; each node is reached via decision to interchange job elements. The second stage selects the parent node for the next generation of alternative sequences through automated paired comparison of objective performance for all current nodes. An application of the heuristic approach to communications satellite systems planning is presented

    HOPE for Homeowners: Too Little, Too Late

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    Heyward argues that the HOPE for Homeowners Act of 2008 is too little, too late for the many homeowners who faced foreclosure in 2007 and the three million homeowners who are predicted to default. Given the significant barriers to success, it is unlikely that the program will prevent a significant number of foreclosures or that it will stabilize the mortgage market. Providing help to 400,000 homeowners is simply not enough, given the magnitude of the problem. The housing market is plagued by 12 million homeowners who owe more than their homes are worth. The problem is compounded by the record number of defaults resulting in foreclosures that lead to even further declines in home values. More comprehensive legislative solutions are sorely needed, and those solutions need to address the current market conditions and the lack of regulation that led to them

    HOPE for Homeowners: Too Little, Too Late

    Get PDF
    Heyward argues that the HOPE for Homeowners Act of 2008 is too little, too late for the many homeowners who faced foreclosure in 2007 and the three million homeowners who are predicted to default. Given the significant barriers to success, it is unlikely that the program will prevent a significant number of foreclosures or that it will stabilize the mortgage market. Providing help to 400,000 homeowners is simply not enough, given the magnitude of the problem. The housing market is plagued by 12 million homeowners who owe more than their homes are worth. The problem is compounded by the record number of defaults resulting in foreclosures that lead to even further declines in home values. More comprehensive legislative solutions are sorely needed, and those solutions need to address the current market conditions and the lack of regulation that led to them

    Lewis Research Center: Commercialization Success Stories

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    The NASA Lewis Research Center, located in Cleveland, Ohio, has a portfolio of research and technology capabilities and facilities that afford opportunities for productive partnerships with industry in a broad range of industry sectors. In response to the President's agenda in the area of technology for economic growth (Clinton/Gore 1993), the National Performance Review (1993), NASA's Agenda for Change (1994), and the needs of its customers, NASA Lewis Research Center has sought and achieved significant successes in technology transfer and commercialization. This paper discusses a sampling of Lewis Research Center's successes in this area, and lessons learned that Lewis Research Center is applying in pursuit of continuous improvement and excellence in technology transfer and commercialization

    Allocations by the 1992 World Administrative Radio Conference

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    An overview of the 1992 World Administrative Radio Conference is presented with viewgraphs. Allocations of radio frequency spectrum are addressed. Mobile satellite service, broadcast satellite service, and uplink power control beacons are also addressed

    Creating Assessment Tools for Students, Adjuncts, and Site Supervisors

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    During this workshop, we plan to explore how clinicians can assess student performance at project, course, and program levels using self-evaluation, peer evaluation, and faculty evaluation (focusing on clinical adjuncts and site supervisors)

    Application of heuristic satellite plan synthesis algorithms to requirements of the WARC-88 allotment plan

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    Creation of an Allotment Plan for the Fixed Satellite Service at the 1988 Space World Administrative Radio Conference (WARC) represented a complex satellite plan synthesis problem, involving a large number of planned and existing systems. Solutions to this problem at WARC-88 required the use of both automated and manual procedures to develop an acceptable set of system positions. Development of an Allotment Plan may also be attempted through solution of an optimization problem, known as the Satellite Location Problem (SLP). Three automated heuristic procedures, developed specifically to solve SLP, are presented. The heuristics are then applied to two specific WARC-88 scenarios. Solutions resulting from the fully automated heuristics are then compared with solutions obtained at WARC-88 through a combination of both automated and manual planning efforts

    Collaborative Aerospace Research and Fellowship Program at NASA Glenn Research Center

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    During the summer of 2004, a 10-week activity for university faculty entitled the NASA-OAI Collaborative Aerospace Research and Fellowship Program (CFP) was conducted at the NASA Glenn Research Center in collaboration with the Ohio Aerospace Institute (OAI). This is a companion program to the highly successful NASA Faculty Fellowship Program and its predecessor, the NASA-ASEE Summer Faculty Fellowship Program that operated for 38 years at Glenn. The objectives of CFP parallel those of its companion, viz., (1) to further the professional knowledge of qualified engineering and science faculty,(2) to stimulate an exchange of ideas between teaching participants and employees of NASA, (3) to enrich and refresh the research and teaching activities of participants institutions, and (4) to contribute to the research objectives of Glenn. However, CFP, unlike the NASA program, permits faculty to be in residence for more than two summers and does not limit participation to United States citizens. Selected fellows spend 10 weeks at Glenn working on research problems in collaboration with NASA colleagues and participating in related activities of the NASA-ASEE program. This year's program began officially on June 1, 2004 and continued through August 7, 2004. Several fellows had program dates that differed from the official dates because university schedules vary and because some of the summer research projects warranted a time extension beyond the 10 weeks for satisfactory completion of the work. The stipend paid to the fellows was 1200perweekandarelocationallowanceof1200 per week and a relocation allowance of 1000 was paid to those living outside a 50-mile radius of the Center. In post-program surveys from this and previous years, the faculty cited numerous instances where participation in the program has led to new courses, new research projects, new laboratory experiments, and grants from NASA to continue the work initiated during the summer. Many of the fellows mentioned amplifying material, both in undergraduate and graduate courses, on the basis of the summer s experience at Glenn. A number of 2004 fellows indicated that proposals to NASA will grow out of their summer research projects. In addition, some journal articles and NASA publications will result from this past summer s activities. Fellows from past summers continue to send reprints of articles that resulted from work initiated at Glenn. This report is intended primarily to summarize the research activities comprising the 2004 CFP Program at Glenn. Particular research studies include: 1) Development of an Imaging-Based, Computational Fluid Dynamics Tool to Assess Fluid Mechanics in Experimental Models that Simulate Blood Vessels; 2) Analysis of Nanomaterials Produced from Precursors; and 3) LEO Propagation Analysis Tool

    Numerical arc segmentation algorithm for a radio conference: A software tool for communication satellite systems planning

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    The Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) provides a method of generating predetermined arc segments for use in the development of an allotment planning procedure to be carried out at the 1988 World Administrative Radio Conference (WARC) on the Use of the Geostationary Satellite Orbit and the Planning of Space Services Utilizing It. Through careful selection of the predetermined arc (PDA) for each administration, flexibility can be increased in terms of choice of system technical characteristics and specific orbit location while reducing the need for coordination among administrations. The NASARC software determines pairwise compatibility between all possible service areas at discrete arc locations. NASARC then exhaustively enumerates groups of administrations whose satellites can be closely located in orbit, and finds the arc segment over which each such compatible group exists. From the set of all possible compatible groupings, groups and their associated arc segments are selected using a heuristic procedure such that a PDA is identified for each administration. Various aspects of the NASARC concept and how the software accomplishes specific features of allotment planning are discussed

    Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC), version 4.0: User's manual

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    The information in the NASARC (Version 4.0) Technical Manual (NASA-TM-101453) and NASARC (Version 4.0) User's Manual (NASA-TM-101454) relates to the state of Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) software development through November 1, 1988. The Technical Manual describes the NASARC concept and the algorithms used to implement the concept. The User's Manual provides information on computer system considerations, installation instructions, description of input files, and program operation instructions. Significant revisions were incorporated in the Version 4.0 software over prior versions. These revisions have further enhanced the modeling capabilities of the NASARC procedure and provide improved arrangements of predetermined arcs within the geostationary orbit. Array dimensions within the software were structured to fit within the currently available 12-megabyte memory capacity of the International Frequency Registration Board (IFRB) computer facility. A piecewise approach to predetermined arc generation in NASARC (Version 4.) allows worldwide planning problem scenarios to be accommodated within computer run time and memory constraints with enhanced likelihood and ease of solution
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