5,299 research outputs found
Random sampling adaptively focusing synthetic aperture radar
A high resolution narrow angle of view imaging radar system is considered that employs an airborne synthetic aperture of 600 meters operating at X-band to produce a beamwidth of approximately 0.05 mr. This system differs from a conventional SAR in that only a smaller number of wavefront samples, spaced randomly over the aperture are processed, and adaptive beamforming with open loop scanning is used. As a result, the processing requirements are reduced to within the capability of present day small computer technology, and the tolerance on flight stability is loosened by about 100:1. The system is described and initial analysis and evaluation results are presented
Dynamic equilibrium economies: a framework for comparing models and data
We propose a constructive, multivariate framework for assessing agreement between (generally misspecified) dynamic equilibrium models and data, a framework which enables a complete second-order comparison of the dynamic properties of models and data. We use bootstrap algorithms to evaluate the significance of deviations between models and data, and we use goodness-of-fit criteria to produce estimators that optimize economically relevant loss functions. We provide a detailed illustrative application to modeling the U.S. cattle cycle.Equilibrium (Economics) - Mathematical models ; Cattle trade
Biochemical characteristics and antibiogram patterns of some gram-negative nonfermentors
This study was undertaken, chiefly, for the purpose of characterizing biochemically a random sample of non fermentative bacilli obtained from local hospitals and determining the prevalence of Ps. aeruginosa among them. A second objective was to compare the antibiogram patterns obtained in this study with those reported by other investigators, and thirdly to establish a baseline for future comparative studies
Recovery from Hepatorenal Syndrome after Orthotopic Liver Transplantation
Three patients with progressive renal failure and advanced hepatic insufficiency due to cirrhosis of the liver underwent orthotopic liver transplantation. All three patients had immediate improvement in hepatic function and within two weeks after liver replacement regained nearly normal kidney function. However, the renal recovery was delayed in each case, and its course was not uniform. Plasma renin activity was high, and renin substrate was low before transplantation in one case in which these measurements were obtained; both returned to normal soon after liver replacement. (N Engl J Med 289:1155–1159, 1973). © 1973, Massachusetts Medical Society. All rights reserved
Study of large adaptive arrays for space technology applications
The research in large adaptive antenna arrays for space technology applications is reported. Specifically two tasks were considered. The first was a system design study for accurate determination of the positions and the frequencies of sources radiating from the earth's surface that could be used for the rapid location of people or vehicles in distress. This system design study led to a nonrigid array about 8 km in size with means for locating the array element positions, receiving signals from the earth and determining the source locations and frequencies of the transmitting sources. It is concluded that this system design is feasible, and satisfies the desired objectives. The second task was an experiment to determine the largest earthbound array which could simulate a spaceborne experiment. It was determined that an 800 ft array would perform indistinguishably in both locations and it is estimated that one several times larger also would serve satisfactorily. In addition the power density spectrum of the phase difference fluctuations across a large array was measured. It was found that the spectrum falls off approximately as f to the minus 5/2 power
Performance, emissions, and physical characteristics of a rotating combustion aircraft engine
The RC2-75, a liquid cooled two chamber rotary combustion engine (Wankel type), designed for aircraft use, was tested and representative baseline (212 KW, 285 BHP) performance and emissions characteristics established. The testing included running fuel/air mixture control curves and varied ignition timing to permit selection of desirable and practical settings for running wide open throttle curves, propeller load curves, variable manifold pressure curves covering cruise conditions, and EPA cycle operating points. Performance and emissions data were recorded for all of the points run. In addition to the test data, information required to characterize the engine and evaluate its performance in aircraft use is provided over a range from one half to twice its present power. The exhaust emissions results are compared to the 1980 EPA requirements. Standard day take-off brake specific fuel consumption is 356 g/KW-HR (.585 lb/BHP-HR) for the configuration tested
Predicting New Product Success or Failure: A Comparison of U.S. and U.K. Practices
We propose a model that allows managers to assess new product development (NPD) projects, combined with the anticipated strategy, prior to introduction and to estimate a probability of success. This model allows for an evaluation and prioritization of resource commitments. A test of this model that compares companies within the United States (U.S.) and the United Kingdom (U.K.) is provided
Book Reviews
The Law Practice of Alexander Hamilton By Julius Goebel, Ed. and Associate Editors New York and London: Columbia University Press, 1964. Pp. XXV, 898.
reviewer: Elliot E. Cheatham
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Lawyers in Politics: A Study in Professional Convergence By Heinz Eulau and John D. Sprague Indianapolis: Bobbs-Merrill,1964. Pp. 164. $1.95.
reviewer: Joseph B. Board, Jr.
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Occupational Disability and Public Policy Edited by Earl F. Cheit and Margaret S. Gordon. New York: John Wiley and Sons,Inc., 1963. Pp. xii, 446.
reviewer: Monroe Berkowit
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