1,116 research outputs found

    Rendezvous strategy impacts on CTV avionics design, system reliability requirements, and available collision avoidance maneuvers

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    Rockwell International is conducting an ongoing program to develop avionics architectures that provide high intrinsic value while meeting all mission objectives. Studies are being conducted to determine alternative configurations that have low life-cycle cost and minimum development risk, and that minimize launch delays while providing the reliability level to assure a successful mission. This effort is based on four decades of providing ballistic missile avionics to the United States Air Force and has focused on the requirements of the NASA Cargo Transfer Vehicle (CTV) program in 1991. During the development of architectural concepts it became apparent that rendezvous strategy issues have an impact on the architecture of the avionics system. This is in addition to the expected impact on propulsion and electrical power duration, flight profiles, and trajectory during approach

    Preliminary analysis of Carter’s energy conservation plan with respect to New England issues

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    An application of a generalized management information system to energy policy and decision making : the user's view

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    This paper presents an approach to the development and use of management information systems that is particularly applicable to systems with the following characteristics: - several classes of users, each of which has a different degree of sophistication - complex and changing security requirements - data exhibits complex and changing inter-relationships - changing needs to be met by information system - must be built quickly nd inexpensively - complex data validation requirements The approach is hierarchical from the user's view in that he may access the system at distinct levels, corresponding to his degree of computer sophistication. A casual user has high level primitives to work with, while an experienced user has more flexible but more detailed low- level primitives. We also have advocated that such systems be implemented in a hierarchical fashion, because this technique provides for ease of debugging, independence of hardware, and a basis for investigating properties of completeness, integrity, correctness, and performance

    NEEMIS : text of governors presentation of October 6, 1975

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    Prepared in association with the Alfred P. Sloan School of ManagementThis is the text of a presentation given to the six New England governors on November 7, 1975. The presentation focused on explaining how the New England Energy Management Information System (NEEMIS) has helped the region, what it is, how it will continue to help the region, what unique technology made it possible, what shall be done in the future, and a demonstration of one application

    GMIS : an experimental system for data management and analysis

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    Prepared in association with the Sloan School of Managemen

    Creation, Coordination, and Activation of Resources in Physics and Mathematics Learning

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    This project seeks to study introductory college level courses in physics, mechanics, and mathematics. The research questions involve the processes by which students become able to use resources across contexts (such as between mathematics and physics), how ideas in math and physics form a resource network, and what mechanisms trigger individual resources or coordinated networks. The researcher will conduct clinical interviews, small group interviews, and statistical analysis of survey questions as well as videos from classroom and help sessions. The data being collected would be analyzed for purpose of describing the development of students as they refine skills in mathematics and physical reasoning. A small group of students (15) at the University of Maine will be the subject of the study.The outcome of this project is expected to be a better model of student reasoning and learning . The reviewers were particularly interested in the possibly useful observations about the connections between mathematics and physics learning. Papers would be prepared for all education research associations, including physics

    Factors affecting residential heating energy consumption

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    Twenty per cent of all energy consumed in New England and ten per cent of all energy consumed in the United States is consumed in home heating. This paper reports on an effort to ascertain the major factors affecting the consumption of home heating oil. Three general classes of factors are analyzed: (1) physical and occupant characteristics (number of rooms, number of occupants, number of stories, amount of insulation, income level, etc.); (2) external (price, shortage awareness, weather); and (3) behavioral and physical changes (change in temperature settings, change in insulation, change in oil burner, etc.). The study is based on four data series: (1) actual monthly home heating oil consumption data on 8000 suburban homeowners in suburban Boston; (2) questionnaire responses from 2000 homeowners on their homes' physical and occupant characteristics, as well as changes in physical and occu- pant behavioral characteristics between 1972 and 1975; (3) monthly weather data; and (4) heating oil price data. The data is associated with the years from 1972 through 1975, a period in which marked price changes, shortages, and behavioral changes occurred, hence providing an opportunity to study the effects of these various events. Three models are central to the study: Model I. A cross-sectional model that depicts consumption per degree-day as a function of physical and occupant characteristics of a home. Model II. A time series regression model that establishes consumption per degree-day as a function of price and consumer awareness of an energy shortage. Model III. A cross-sectional regression model that attempts to explain change in consumption per degree-day from one year to the next as a function of specific conservation actions such as temperature resetting, addition of storm windows, etc. The major findings of each model are as follows: Model I: House size, age of home, family income, and the presence of storm doors and windows are all significant factors in predicting the amount of home oil consumption. Model II: Estimated values of price elasticity with respect to demand for residential heating oil and a measure of 'mnpact of shortage awareness on consumption are determined. This model also demonstrates that there were substantial savings in consumption corresponding to increases in price and shortage awareness from 1972-1975. Model III: he data from the questionnaire indicate that only a few consumers made physical home improvements; however, the data from the oil company indicate that a substantial savings (over 12%) in consumption occurred between the heating seasons 1972/73 and 1973/74. The conclusion from this data indicates that behavioral changes were the major conservation actions taken. Model III indicates that the behavioral change of temperature resetting is significant and the physical change of additional weather stripping and change of burner are significant. Further study is needed, however, to determine those behavioral changes that accounted for the major change in consumption. In addition, this model indicates that different groups within the sample (e.g., by income level, house characteristics) display similar conservation efficiency. In addition to the findings of the models, the paper includes (in Appendix B) a detailed discussion of biases associated with the data. Major conclusions from that discussion are: (1) our sample is representative of suburban homes in the Northern United States; (2) the consumers who responded to the questionnaire were slightly more energy- conscious and responded slightly more dramatically to price increases than the general populace; (3) our residential heating oil prices are representative of those that prevailed in the region; and (4) the heating seasons 1972 through 1975 were warmer than usual. Trends in the data indicate that new homes in the sample have a considerable amount of insulation and the typical single-family house in the sample has storm windows and doors.New England Regional Commission, NEEMIS Project Contract no. 10630776 and the M.I.T./IBM Joint Study Agreemen

    Toward An Axiomatic Approach to Information Systems Development

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    This paper advocates an approach called the axiomatic method to reduce the costs of constructing an information system. Further, we contrast the applicability of the axiomatic method to the more traditional approach of enumerating alternatives (the algorithmic method) in constructing an information system. We delineate the steps involved in building an information system, present a set of pilot axioms, and offer some derivative theorems. We then apply these axioms and theorems to each phase (specification, design, implementation, and maintenance) of the information system life cycle, and confirm a number of empirical results other information system builders have observed

    Polyethylene Frequency Spectrum from ``Warm''‐Neutron Scattering

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71280/2/JCPSA6-42-12-4299-1.pd
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