9,439 research outputs found
Tank Tests of a Model of the NC Flying-boat Hull - N.A.C.A. Model 44
A 1/7.06 full-size model of the NC-type hull was tested in the N.A.C.A. tank by both the general method and the specific or free-to-trim method. The results of the tests are given in curves plotted as non dimensional coefficients and are compared with the test results of N.A.C.A. model 11-A. The NC model (N.A.C.A. model 44) shows higher resistance than model 11-A at hump speed but lower resistance at high speeds. Model 44 has a higher best trim angle at the jump and a lower maximum positive trimming moment than model 11-A. At high speeds the best trim angle and the trimming moments of the two models are approximately the same
Tank Tests of Two Floats for High-speed Seaplanes
At the request of the Bureau of Aeronautics, Navy Department, a study of the design of floats especially suitable for use on high-speed seaplanes was undertaken in the N.A.C.A. tank. This note give the results obtained in tests of one-quarter full-size models of two floats for high-speed seaplanes. One was a float similar to that used on the Macchi high-speed seaplane which competed in the 1926 Schneider Trophy races, and the other a float designed at the N.A.C.A. tank in an attempt to improve on the water performance of the Macchi float. The model of the latter showed considerably better water performance than the model of the Macchi float
THE RURAL TOWN AS A PRODUCING UNIT: AN EMPIRICAL ANALYSIS AND IMPLICATIONS FOR RURAL DEVELOPMENT POLICY
Community/Rural/Urban Development,
Unionization and cost of production: compensation, productivity, and factor-use effects
A demonstration that unionization can affect cost of production through increases in compensation, through shifts in technologies, and through deviations from the least-cost combination of inputs (the factor-use effect).Labor productivity ; Wages ; Labor unions
AN ANALYSIS OF CONSUMER CHARACTERISTICS ASSOCIATED WITH THE PURCHASE OF BEEF AND PORK VARIETY MEATS
This analysis uses a dichotomous qualitative response model to assess the influences of several economic and demographic characteristics of consumers on the purchase decision for variety (edible organ and offal) meats. Specific factors considered include education, age, income, household size, and ethnic heritage. Data collected from a survey of 3,340 consumers are utilized. Results confirm strong income, age, household size, and ethic effects on the purchase of variety meats.Consumer/Household Economics,
Metropolitan wage differentials: can Cleveland still compete?
A look at the Cleveland metropolitan labor market as a point of comparison to highlight how labor costs in a major industrial city fare with respect to other U.S. cities. ; A look at the Cleveland metropolitan labor market as a point of comparison to highlight how labor costs in a major industrial city fare with respect to other U.S. cities.Wages ; Cleveland (Ohio) ; Urban economics
Exact reconstruction of gene regulatory networks using compressive sensing.
BackgroundWe consider the problem of reconstructing a gene regulatory network structure from limited time series gene expression data, without any a priori knowledge of connectivity. We assume that the network is sparse, meaning the connectivity among genes is much less than full connectivity. We develop a method for network reconstruction based on compressive sensing, which takes advantage of the network's sparseness.ResultsFor the case in which all genes are accessible for measurement, and there is no measurement noise, we show that our method can be used to exactly reconstruct the network. For the more general problem, in which hidden genes exist and all measurements are contaminated by noise, we show that our method leads to reliable reconstruction. In both cases, coherence of the model is used to assess the ability to reconstruct the network and to design new experiments. We demonstrate that it is possible to use the coherence distribution to guide biological experiment design effectively. By collecting a more informative dataset, the proposed method helps reduce the cost of experiments. For each problem, a set of numerical examples is presented.ConclusionsThe method provides a guarantee on how well the inferred graph structure represents the underlying system, reveals deficiencies in the data and model, and suggests experimental directions to remedy the deficiencies
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