1,116 research outputs found
Rendezvous strategy impacts on CTV avionics design, system reliability requirements, and available collision avoidance maneuvers
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
An application of a generalized management information system to energy policy and decision making : the user's view
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
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
Prepared in association with the Sloan School of Managemen
Creation, Coordination, and Activation of Resources in Physics and Mathematics Learning
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
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
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
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71280/2/JCPSA6-42-12-4299-1.pd
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