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121.
Tiersten HF 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2003,50(11):1436-1443
A modal representation of the thickness vibrations of rotated Y-cut quartz plates, which was used in the treatment of driven transversely varying thickness modes, is shown to be defective in certain respects. The differential equations and edge conditions for transversely varying thickness modes have been used in the accurate treatment of trapped energy resonators, monolithic crystal filters, and contoured quartz resonators, even though those defects were present. In this work those defects in the thickness solution are corrected along with the influence on the differential equations and edge conditions in the transversely varying case. The corrected modal representation shows that, because in practical applications to the above mentioned devices, the driving frequency is always near a thickness resonant frequency, essentially the same results will be obtained with the corrected representation as were obtained with the defective one, which explains why the results obtained with the defective equations were so accurate. 相似文献
122.
Loffler G Orbach HS 《Journal of the Optical Society of America. A, Optics, image science, and vision》2003,20(8):1461-1471
The perceived direction of motion of a featureless contour inside a circular aperture is always perpendicular to the contour's orientation, regardless of its true motion (the aperture problem). This study investigates the circumstances under which unambiguous feature motion (of line terminators, single dots, or truncations of a D6 pattern) in adjacent apertures can alter the perceived direction of such featureless contours. We find that integration mechanisms responsible for motion capture are fairly robust against misorientations and contrast manipulations of individual components, are sensitive to differences in spatial frequencies, and scale with pattern size. Motion capture is not diminished when a D6 profile is substituted for the square-pulse profile of a line and is independent of the visibility of the apertures, indicating that object interpretations and three-dimensional analyses of a scene are less important than has been postulated previously. These results have strong implications for the neuronal hardware underlying the integration of motion signals across space and provide a framework for global motion models. 相似文献
123.
124.
Harry McCracken 《微电脑世界》2007,(4):184-184
Google Apps现在还只处在基础阶段,虽然短期内还不能对Office构成威胁,但只要Gooqle想打倒微软,就绝对有可能。 相似文献
125.
Eric Wade Harry Asada 《Pervasive Computing, IEEE》2007,6(1):52-58
Theoretical analysis and experimentation show that a prototype body area network composed of 20 electrically conductive fabric sheets can transmit both signals and DC power sufficient for implementing a cable-free network in a garment. This wearable system has broad applications. The applications presented represent just two areas where our garment technology can be useful in the health-monitoring domain. As wearable computing matures, alternative electronic systems like ours can play a larger role in applications. Meanwhile, the DC-PLC system we've developed presents a workable model for the design of CF garments 相似文献
126.
Protein‐Encapsulated Catalysts: WO3 Nanofiber‐Based Biomarker Detectors Enabled by Protein‐Encapsulated Catalyst Self‐Assembled on Polystyrene Colloid Templates (Small 7/2016) 下载免费PDF全文
127.
In models of first-price auctions, when bidders are ex ante heterogeneous, deriving explicit equilibrium bid functions is typically impossible, so numerical methods are often employed to find approximate solutions. Recent theoretical research concerning asymmetric auctions has determined some properties these bid functions must satisfy when certain conditions are met. Plotting the relative expected pay-offs of bidders is a quick, informative way to decide whether the approximate solutions are consistent with theory. We approximate the (inverse-)bid functions by polynomials and employ theoretical results in two ways: to help solve for the polynomial coefficients and to evaluate qualitatively the appropriateness of a given approximation. We simulate auctions from the approximated solutions and find that, for the examples considered, low-degree polynomial approximations perform poorly and can lead to incorrect policy recommendations concerning auction design, suggesting researchers need to take care to obtain quality solutions. 相似文献
128.
Harry K.H. Chow Winson Siu Chi-Kong Chan Henry C.B. Chan 《Expert systems with applications》2013,40(10):3858-3871
This paper advocates the use of multi-agent systems in the freight forwarding industry. We propose an intelligent mobile agent system to cope with a dynamic freight forwarding environment where up-to-date information is crucial but time-consuming to obtain. A key component of our system is an agent argumentation mechanism that allows decision support agents to discuss, argue, and come to a compromise in order to derive well-explained freight planning solutions. A number of artificial intelligence mechanisms are implemented, namely: (1) a mobile-agent-based automated information gathering mechanism, where designated mobile agents access various websites automatically to gather information (e.g., weather conditions on a candidate route) critical for cargo consolidation and route planning, (2) a fuzzy logics engine for risk evaluation, and (3) a simulated annealing engine for optimizing cargo consolidation. A system prototype is developed and the feasibility of our approach is demonstrated in a case study. A series of experiments are also conducted to evaluate the system’s performance. 相似文献
129.
Adsorption of lutein from crude soybean oil miscella on dispersed silicic acid resulted in three different Freundlich type
isotherms, depending on the amount of adsorbent used. Normally, changing the amount of adsorbent gives a new point on the
same isotherm. Further investigation of the lutein adsorption revealed that addition of 1% isopropanol to the hexane solvent
and deactivation of the silica acid with water decreased lutein adsorption. Purification of the lutein resulted in increased
adsorption, indicating that triglyceride was competing for adsorption sites. The triglyceride competition was confirmed by
calculating an adsorption isotherm for triglyceride from crude soybean oil miscella. Use of silicic acid as a column rather
than dispersed yielded multiple isotherms for lutein adsorption based on the amount of adsorbent used. Also, lutein adsorption
on columns was concentrated at the entrance to the column. Experiments showed that lutein adsorption was not due to partitioning
between bound triglyceride and hexane solvent. 相似文献
130.
Although methods of product design and materials selection have been developed, the recent rise of multimaterials (composites, hybrids, etc.) has shown a lack of tools for engineering in this domain. The present contribution aims at the development of a multimaterials design method based on the adaptation of existing methods and on the conclusions of a case study. In comparison with materials selection, the originality of multimaterials design relates to searching materials coupling mechanisms to satisfy a set of requirements. More, it appears that manufacturing process and validation tests are very important points that must be integrated early in the design process. 相似文献