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IEEE 1994 National Aerospace and Electronics conference (NAECON 1994)

作者： HE, SH SUN, WF GUO, GR CHANGSHA INST TECHNOL DEPT ELECT ENGNHUNAN 410073PEOPLES R CHINA

ISBN: (纸本)0780318935

A new data extrapolation algorithm is presented for guidance and target recognition application. The algorithm firstly uses DFT or FFT computation of L points data of response over band (f/sub o/,f/sub o/+/spl Delta/F) to obtain the rough outline of target range profile. Then a CFAR detector is used to obtain the structure window function X/sub w/(e/sup j/spl omega) and its IFT series X/sub w/(l) and several filtering functions {H/sub j/(z)} are constructed. Finally, the extrapolation process by using the filtered series {y/sub j/(l)} based on X/sub w/(e/sup j/spl omega) restriction is established. The algorithm has the advantage of robustness under clutter background.

关键词： image recognition image processing extrapolation fast Fourier transforms radar systems data extrapolation target recognition guidance target range profile structure window function filtered series clutter robustness discrete Fourier transform fast Fourier transform radar systems

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THE PERCEPTION OF THE IMPACT OF guidance SERVICES IN SOME SELECTED SECONDARY SCHOOLS IN ZARIA, KADUNA STATE

THE PERCEPTION OF THE IMPACT OF GUIDANCE SERVICES IN SOME SE...

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作者： BOLARIN W. VICTORIA AHMADU BELLO UNIVERSITY

学位级别：硕士

The study investigated the extent and organisation of guidance services in some secondary schools so as to assess the impact of guidance services on the lives of students. The main objective was to find out what the schools were doing to meet the educational, social and personal needs of the stuaents, and the means by which students could be better helped to understand themselves and plan for their future careers. Two main research questions were posed and answered. In addition, the following null hypotheses were stated and tested at 0.05 level of significance: 1. There is no significant difference between male and female students* needs for guidance services in the selected secondary schools. 2. There is no significant difference between students' ages and their needs for guidance servicer, 3. There is no significant difference between the mean scores of day and boarding students with respect of their needs for guidance services in secondary schools. ix The sample size of 308 respondents was randomly chosen out of which 296 were from Junior Secondary Three and Senior Secondary Two while 12 school counsellors were drawn from the six sample schools. The main instruments used for the study were the questionnaire and structured interview which were designed by the researcher. ANOVA and t-test statistical tools were used to analyse the data. Hypotheses 1 was retained while, hypotheses 2 and 3 were rejected. The study revealed the following: 1. That age has no significant effect on students' need for counsel-ling. That is to say both old and young need guidance services. 2. That guidance services have not yet made any appreciable impact in most of these schools under study. From the findings the following major recommendations were made: (a) That school administrations should provide some infrastructure, such as counsel-ling rooms adequate furniture and adequate funds to equip counsel-ling rooms. X (b) That the teaching load of the guidance masters should be greatly redu

关键词： PERCEPTION IMPACT guidance SERVICES SELECTED SECONDARY SCHOOLS ZARIA KADUNA STATE

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Effects of Physical guidance and Knowledge of Results on Motor Learning: Support for the guidance Hypothesis

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Research Quarterly. American Association for Health and Physical Education 1994年第4期65卷 316-323页

The guidance hypothesis (Schmidt, 1991) predicts that the guiding properties of augmented feedback are beneficial for motor learning when used to reduce error, but detrimental when relied upon. Therefore, a heavily guiding form of feedback might be detrimental for learning. In addition, the guidance hypothesis predicts that practice with a high relative frequency of augmented feedback would be detrimental for learning. An experiment is described that crossed two forms of feedback with two levels of relative frequency. Subjects practiced movements to a target with either physical guidance or knowledge of results, and with either a high or faded relative frequency. The high frequency physical guidance condition resulted in the poorest retention, and both high frequency feedback conditions resulted in the least accuracy in transfer. These results provide support for the guidance hypothesis and suggest consideration of the combined effects on learning of the type and relative frequency of augmented feedback and acquisition-test conditions.

关键词： learning guidance knowledge of results motor skills

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Optimal guidance of a Solar Sail Spacecraft to the Sun-Earth L 2 Point

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IFAC Proceedings Volumes 1994年第13期27卷 29-34页

作者： S.H. Hur A.E. Bryson Space Systems/Loral Palo Alto CA 94303 USA Stanford University Department oj Aeronautics and Astronautics Stanford CA 94305 USA

The guidance of a solar sail spacecraft from an Earth orbit to a point near the Sun-Earth L2 libration point is investigated in this paper. An open-loop trajectory is first computed by maximizing the rate of energy increase during the spiral segment and applying minimum-time optimal control for the remainder of the transfer. A follower guidance logic is employed in the spiral segment and a neighboring extremal feedback guidance is applied in the remaining transition segment.

关键词： Optimal control guidance solar sail three-body problem low-thrust

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VA/DOD HEALTH CARE: More guidance Needed to Implement CHAMPUS Funded Sharing Agreements

VA/DOD HEALTH CARE: More Guidance Needed to Implement CHAMPU...

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作者： Brown, J United States General Accounting Office WASHINGTON DC

In February 1994, after nearly 3 years of negotiation, VA and DOD agreed on a framework for VA to treat CHAMPUS-eligible beneficiaries and receive reimbursement from CHAMPUS funds. Implementation of CHAMPUS/VA sharing agreements has been delayed because of disagreements between DOD and VA over VA hospital requirements. DOD wanted VA hospitals to be subject tothe same requirements as civilian hospitals under CHAMPUS. Disagreements continued until the Chairman, House Committee on Veterans Affairs, intervened.

关键词： Health care Department of veterans affairs Department of defense Military medicine Hospitals Agreements Health services Military hospitals Congress Accounting guidance

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MULTIOBJECTIVE HEURISTIC-SEARCH IN AND/OR GRAPHS

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IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS 1995年第11期25卷 1513-1521页

作者： LIAW, CF STEWART, BS WHITE, CC US WEST ENGLEWOODCO 80111 UNIV MICHIGAN ANN ARBORMI 48109

We develop and analyze a heuristic search algorithm that determines the nondominated set of solution graphs for a multiobjective AND/OR graph, This algorithm, MOAO*, is a multiobjective generalization of AO*, MOAO* uses sets of vector-valued heuristic estimates to give guidance to the search, We show that MOAO* satisfies termination, completeness, and admissibility conditions, generalizing results associated with AO*. Further, we prove that if the heuristic sets satisfy a monotonicity condition, then MOAO* possesses an efficiency property reminiscent of a well-known result associated with A*.

关键词： heuristic searching algorithms Heuristics SETTING heuristic search SEARCHING ALGORITHM Writers AUXILIARY ORIFICES guidance Acceptability

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A REVIEW OF PROCEDURES FOR UPDATING AIR-QUALITY MODELING TECHNIQUES FOR REGULATORY PROGRAMS

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JOURNAL OF APPLIED METEOROLOGY 1995年第3期34卷 731-737页

作者： TOUMA, JS IRWIN, JS TIKVART, JA COULTER, CT NOAA AIR RESOURCES LABDIV ATMOSPHER SCI MODELINGRES TRIANGLE PKNC

Air quality models are a key component in determining pollution control requirements. To ensure that the best techniques are used, modeling guidance must be flexible and include better techniques as they become available. Revisions to modeling guidance require an assessment of the scientific basis, a model performance evaluation using observed data, sensitivity analysis for impact on design concentrations and data input requirements, and public review and comment before formal adoption in regulatory programs. The procedures used in reviewing new techniques are examined in this paper, and past actions are discussed. The appropriateness of adopting a new method for modeling area sources characterized by low-level releases with little buoyancy is provided as an example of the revision review process. While this process is lengthy, it ensures that decisions on potentially costly pollution controls are based on full public participation and sound scientific developments.

关键词： Modeling Air quality models Performance Evaluation Comment Ensure Public Participation new methods FLEXIBLE guidance Technology data entry LOW LEVEL

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CART DECISION-TREE STATISTICAL-ANALYSIS AND PREDICTION OF SUMMER SEASON MAXIMUM SURFACE OZONE FOR THE VANCOUVER, MONTREAL, AND ATLANTIC REGIONS OF CANADA

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JOURNAL OF APPLIED METEOROLOGY 1995年第8期34卷 1848-1862页

作者： BURROWS, WR BENJAMIN, M BEAUCHAMP, S LORD, ER MCCOLLOR, D THOMSON, B ENVIRONM CANADA ST LAURENTPQCANADA ENVIRONM CANADA BEDFORDNSCANADA ENVIRONM CANADA VANCOUVERBCCANADA

Prediction of daily maximum surface ozone (O-3) concentration was begun by Environment Canada in the spring of 1993 for the Vancouver, Montreal, and Atlantic regions in order to advise the public of expected air quality. Forecasts have been issued for southern Ontario for many years by the province of Ontario, but this is a new undertaking in other parts of the country, where air quality has become a concern in recent years, There is a need for guidance to prepare the forecasts, particularly for prediction of surface O-3 concentration levels near or exceeding the Canadian 1-h maximum acceptable concentration of 82 ppb. Such occurrences are episodic and relatively rare in southern Canada. Probability of occurrence is in the range 0.00-0.08 at the sites in the regions studied here, thus, reliable prediction is difficult without guidance, Mesoscale numerical meteorological-photochemical models are not currently available for routine use in operations, but the capability exists for development and use of sophisticated multivariate statistical techniques for prediction of daily maximum O-3 concentration. Most statistical ozone forecast procedures to date in Canada have been based on multiple linear regression with a limited number of predictors mainly drawn from surface meteorology and subjective classification of the synoptic meteorological flow pattern, Since the relationship between surface O-3 and meteorology is nonlinear, tree-based statistical models with several predictors are appropriate for developing objective forecast guidance. Surface and upper-air meteorological predictor;and other predictors were matched with several years of observed daily maximum O-3 concentrations for the months of May-September at air-monitoring sites in the three regions. A recent nonparametric data-driven tree-based analysis method known as CART (classification and regression trees) was used to analyze the data at each site. The decision trees built by CART were found to fit the data

关键词： Decision Trees Vancouver ozone Canada Region of Canada total maximum daily load Meteorology Disease Predictive Factor guidance Surfaces

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DEVELOPMENT OF THE SPECIFICATION FOR GROUND INVESTIGATION

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PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-GEOTECHNICAL ENGINEERING 1995年第1期113卷 19-24页

作者： GREENWOOD, JR COBBE, MI SKINNER, RW Travers Morgan Ltd United Kingdom M. J. Carter Associates Ltd United Kingdom Foundation and Exploraiion Services Ltd United Kingdom

The Specification for ground investigation (1993)(1) has been prepared and published as part of the Site Investigation Steering Group initiative for improved practice in site investigation, The development of the specification, based on earlier specifications by the Department of Transport (1987)(5) and the Institution of Civil Engineers (1989),(6) is described together with the philosophy adopted in its preparation, Problems with the previously existing specifications are noted, The format of the new document and the use of schedules to provide detailed information for a particular contract are described, The Paper describes the elements of the specification including the comprehensive notes for guidance and the bill of quantities, A formal method of measurement is not necessary but the option of including one to suit the Client's requirements is recognized, New and extended topics are summarized including the investigation of contaminated ground, Finally, users are invited to provide feedback and comment on the use of the specification, The contribution and support of the construction industry in its preparation is acknowledged.

关键词： TRAVERS MORGAN , M J CARTER , SITE INVESTIGATION STEERING GROUP FOUNDATION & EXPLORATION SERVICES GROUND , INVESTIGATIONS , SPECIFICATIONS , DEVELOPMENT , SITE INVESTIGATION , CONTRACTS , guidance , NOTES , BILLS , QUANTITIES , CONTAMINATED , CONTRACTORS , GEOTECHNICS , SCHEDULES , DOCUMENTATION , CLAUSES

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FUEL-OPTIMAL BANK-ANGLE CONTROL FOR LUNAR-RETURN AEROCAPTURE

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JOURNAL OF SPACECRAFT AND ROCKETS 1995年第1期32卷 149-155页

作者： MEYER, JL SILVERBERG, L WALBERG, GD N CAROLINA STATE UNIV RALEIGH NC 27695 USA

Aerocapture is defined as the deceleration of a spacecraft due to drag produced on it by a planet's atmosphere such that the vehicle is captured into orbit about the planet. This is accomplished by varying the direction of the vehicle's lift vector through bank-angle modulation. This paper examines the application of four optimal-control approaches to aerocapture. The first is a minimization of a pseudo fuel cost function, which yields continuous controls. The second is bang-bang control, which minimizes the time associated with bank-angle modulation. Next, an absolute fuel function is minimized, which results in controls in the form of impulses. A fourth approach is a modification to impulsive control, where impulses are approximated by pulses of finite duration. All of the approaches are applied to a single-pass aerocapture problem. The modified impulsive-control approach is applied to a two-pass aerocapture scenario. Recommendations on the practical implementation of these control approaches in the presence of vehicle and atmospheric uncertainties are given.

关键词： guidance vehicle deceleration angle modulation bang-bang control guidance Cost functions aerocapture

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