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81.
82.
Aerodynamic loads on a multi-bladed helicopter rotor in hovering flight were calculated by solving the three-dimensional incompressible Navier-Stokes equations. The rotor wake effects were accounted by the correction of local geometric angle of attack according to a free-wake modeling in addition to an empirical modification for the tip flow effect. The validity and efficiency of the present method were verified by the comparisons between numerical results and experimental data. 相似文献
83.
84.
关于Vague集的模糊熵及其构造 总被引:17,自引:3,他引:14
本文分析了Vague集的性质,给出了将Vague集变换为Fuzzy集的转换函数,并讨论了其性质。分析了关于Vague集的模糊熵的直观特性,在此基础上我们给出了Vague集的模糊熵的定义。最后给出了一个关于Vague集的模糊熵的构造方法。 相似文献
85.
Process characterization and optimization based on censored datafrom highly fractionated experiments
Censored data resulting from life-test of durable products, coupled with complicated structures of screening experiments, makes process characterization very difficult. Existing methods can be inadequate for modeling such data because important effects and factor levels might be identified wrongly. This article presents an expectation-modeling-maximization (EMM) algorithm, where censored data are imputed as pseudo-complete samples and a forward regression is used to compare all main effects and 2-factor interactions for process characterization. Then, the best combination of controllable variables is determined in order to optimize predictions from the final model. A sensitivity study of the selected models, with changes of imputation and parameter estimation methods, shows the importance of using appropriate models and estimation methods in EMM. The author's analysis of the Specht (1985) heat-exchanger life-test data indicates that E, EG, EH in the wall data and A, K, D, DJ in the corner data are the dominating factors. However, in finding the best process recipe, one might use a model with a few additional terms, which leads to more accurate predictions for better process optimization 相似文献
86.
This paper formulates a general framework that includes and extends the existing definitions for network survivability. Based on this framework, network survivability is characterized by a survivability function rather than a single-value survivability measure, and various quantities of interest can be derived from the function. Examples are the expected survivability, the worst-case survivability, the r-percentile survivability, and the probability of zero survivability. The survivability function is especially useful for the study of large-scale disasters. For illustration, the authors derive the survivability function in closed form for a simple ring network under link failures. They also discuss the general procedure for finding survivability functions for complex networks, and show that the survivability function reveals useful information about a network. This framework provides a unified and practical approach to analyzing and designing highly survivable communications networks 相似文献
87.
用发射天线式微波等离子体CVD装置沉积大面积金刚石薄膜 总被引:1,自引:0,他引:1
在国内首次研制成功了高气压发射天线式微波等离子体辅助化学气相沉积金刚石薄膜装置,用该装置成功地在3英寸的单晶硅衬底上沉积了Φ70mm的金刚石薄膜。这一成果填补了国内空白,对我国金刚石薄膜研究领域的设备更新换代和开发应用具有重要意义。 相似文献
88.
89.
Li S. Zhang H. Lu P. Zhu W. Edelman H. Rea C. Tabat N. Mao S. Brown D. Montemorra M. Palmer D. 《IEEE transactions on magnetics》2006,42(12):3874-3879
In perpendicular recording, substantial erasure of the stored data patterns can occur during the writing process. Among all those erasure processes, side-track erasure (STE) is one of the critical issues in drive head/media integration. Unlike the adjacent track erasure (ATE) process, the locations of the STE affected areas are often many tens of tracks away from the central writing track location. In this work, we report on an experimental investigation and quantification of the general attributes and the origins of the STE processes in various situations. Particularly, we thoroughly characterize some distinctive signatures and behaviors of STE processes by employing both the amplitude- and bit-error-rate-based STE measurement methods in combination with a novel magnetic force microscope characterization technique 相似文献
90.
丙烯酸酯与甲基丙烯酸酯的共聚及性能研究 总被引:22,自引:0,他引:22
采用悬浮聚合法,以丙烯酸-2-乙基-己酯与甲基丙烯酸十二酯为单体,合成了共聚型高吸油性树脂。研究了共聚单体的配比、交联剂用量、引发剂用量诸因素对高吸油性树脂的性能影响。制得的树脂可以吸其自身质量的11.8倍的煤油、14.7倍的苯、6.5倍的泵油。 相似文献