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21.
D. P. Phillips, T. E. Ruth, and L. M. Wagner (1993) reported that 1969-1990 California mortality data show that Chinese Americans are particularly vulnerable to diseases that Chinese astrology and traditional Chinese medicine associate with their birth years. For example, because fire is associated with the heart, a Chinese person born in a fire year (such as 1937) is more likely to die of heart disease than is a Chinese person born in a nonfire year. However, many diseases were excluded from this study, some diseases that were included have ambiguous links to birth years, and the statistical tests were indirect. A more complete statistical analysis and independent California mortality data for the years 1960-1968 and 1991-2002 did not replicate the original results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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We study learning of predicate logics formulas from “elementary facts,” i.e. from the values of the predicates in the given model. Several models of learning are considered, but most of our attention is paid to learning with belief levels. We propose an axiom system which describes what we consider to be a human scientist's natural behavior when trying to explore these elementary facts. It is proved that no such system can be complete. However we believe that our axiom system is “practically” complete. Theorems presented in the paper in some sense confirm our hypothesis.  相似文献   
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Cinematic primitives for multimedia   总被引:5,自引:0,他引:5  
The development of robust frameworks in interactive multimedia for representing story elements to the machine so that they can be retrieved in multiple contexts is addressed. Interactive multimedia is discussed as a user-directed form of storytelling, and the nature of cinematic storytelling is examined. It is proposed that content can be represented in layers. This model for layered information will allow programs to take advantage of the relation between cinematic sequences and the world they represent. The collection of content by the camera and microphone is considered in this context. The use of the methodology to build meaningful, context-rich sequences is discussed  相似文献   
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The literature provides little information on high-speed, high-normal-load, plain linear bearings, although the case for two rigid surfaces in relative linear motion can readily be solved by assuming squeeze action resistance. A new genus of internal combustion engines based on the Stiller-Smith mechanism incorporates connecting rods constrained by linear bearings, with the central normal load on the rod restricted by an oil film. A general analysis takes into account the bending of the rod, when the distributed oil film pressure resists the distributed load on the elastic rod. Design charts result that yield the dimensionless velocity at which the rod sinks in the oil as a function of the dimensionless load and the bearing clearance, and predict the deflection of the beam. The rod clearance history simulations for the Stiller-Smith engine compare favourably with computations for the rigid beam, confirming the analysis technique.  相似文献   
27.
Hydroelectric generators of less than 20 kilowatts can be in remote areas served only by a single-phase line. For high efficiency and low cost, a three-phase induction generator should be used. This three-phase generator can operate with balanced voltages and currents when the ``phase-splitting' circuit uses two capacitors connetted to two different single-phase voltage sources.  相似文献   
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The nave of Santa Maria Novella, a Dominican church in Florence Italy is representative of a Florentine Gothic system of construction. This system, consisting of domical rib vaults on square nave bays, high side aisles, and crypto-buttressing, differs substantially from the French high Gothic system of even-level-crown rib vaults on rectangular bays, with flying buttresses over relatively low aisles. An investigation into the structural aspects of the Florentine Gothic construction system reveals that the domical vaults increase the longitudinal thrust and reduce the transverse thrust, which may require additional precautions to be taken during construction, but entails a less elaborate buttressing system. The domical vaults are found to perform well structurally, with an absence of tensile stresses, and are more suitable for a square bay. In general, the structural system of the nave of Santa Maria Novella is found to be the product of carefully considered structural design, which may be accepted as an alternative to the French Gothic construction system.  相似文献   
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This paper presents a particle penetration model predicting particle penetration coefficient (Pp) through a narrow crack of arbitrary incline angles (θ). The objective was to simulate Pp for outdoor-to-indoor particle penetration for residential infiltration conditions. This model assumes laminar infiltration flow and considers particle deposition from both gravitational sedimentation and Brownian diffusion. For micron-sized particles, modeling results indicate that gravitational sedimentation is the major deposition mechanism. Pp increases monotonically with ∣θ∣ because effective particle sedimentation velocity (vs?cos?θ) decreases monotonically with ∣θ∣. For submicron-sized particles (0.1?μm), Brownian diffusion is the major particle deposition mechanism. Because Brownian diffusion is a nondirectional deposition mechanism, crack inclination did not affect Pp. This study applied this model to estimate Pp for L-shaped cracks, and validated modeling results with experiments. Experimental results indicated that inertial impaction and crack entrance cutoff effects were not significant particle deposition mechanisms for the test micron-sized particles. Gravitational sedimentation was the major deposition mechanism. An L-shaped crack can be simulated as the combination of horizontal and vertical sections. This model agreed reasonably with experimental results.  相似文献   
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