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611.
本文介绍了在线切割电火花机床上加工非圆齿轮的编程方法。详细介绍了对节曲线的拟合及其在上分齿的方法,以及折算齿数的求取及对齿形曲线、齿根过渡曲线的处理方法。  相似文献   
612.
The Mathematical Statistics Theory (MST) and the Mathematical Theory of Stochastic Processes (MTSP) are different branches of the more general Mathematical Probability Theory (MPT) that represents different aspects of some physical processes we can analyze using mathematics. Each model of a stochastic process according to the MTSP can provide one or more interpretations in the MST domain. The importance of MTSP is that each such interpretation can provide large amount of new information. While large body of work on the impact crater statistics according to MST has already been done, it is yet to be investigated as to how we can model a stochastic process according to MTSP; for example, bombardment of the planetary surface or something else in a Lunar and Planetary Science (LPS) domain. In order to show possible achievements, the possible existence of a Martian ocean was chosen as a query that could be addressed through computations using presumptions according to MTSP, including probability of existence as well as lateral and vertical extent and duration of time. While the presumptions for this particular case will also be addressed in certain degree, this will be done primarily to show complexities of some physical process that can be modeled, rather than to prove correctness of the concrete values computed here. While this in itself can be the objective in some future work toward the formal proof of the probability, extent, and timing of oceans on Mars, the basic idea here is to show the basic principles of MTSP, and its potential for addressing LPS-related phenomena. Here, I attempt to show how this approach can: (1) provide large amounts of previously unknown information about physical processes on the surface of the planet, (2) lead to a better understanding of the processes that have shaped the surface of the planet, and/or (3) help constrain the amount of resurfacing. Coupled with other current methodologies, MTSP can result in a better understanding of the history of Mars, as well as other lunar and planetary bodies.  相似文献   
613.
本组系列论文(Ⅰ)-(Ⅴ)从数学和认识论的角度系统地研究了无穷观问题的历史发展和现状,确立了无穷观背景世界的三分法原则,指出了两种无穷观相五排斥的局限性,形成了统一两种无穷于同一框架中的基本观点,并建立了一个统一实无限与潜无限于同一框架中的公理集体论系统APAS。  相似文献   
614.
粗糙集中连续属性离散化的一种新方法   总被引:17,自引:0,他引:17  
提出一种新的间接离散化方法——超曲面法。首先给出了超曲面的定义,证明了超曲面为一个高阶的多项式,且给出了该多项式的总项数;同时证明了超曲面数与最大决策规则数之间的关系。然后提出了应用支持向量机来求取最优超曲面的方法。最后以空军低消耗器材的储存策略为例,说明了超曲面的求解过程。实例仿真结果表明,用支持向量机来求解超曲面,不仅方法简单,而且较容易寻得最优解。结果还表明,文中提出的超曲面间接离散方法能较好地区分决策表中的决策类别,从而获得更为简捷的决策规则。  相似文献   
615.
INTRODUCTIONThe energy of the Richtmyer- Meshkov in-stability is excited by the interaction between ashock wave and a contact interface across thatfluids are different.Itis very important thatcap-ture the interface in multi- material flows exact-ly.Here we will apply the ghost fluid method tosimulate two dimensional Richtmyer- Meshkovinstability.The mathematical equation used to simulatethe Ritchmyer- Meshkov instability is the com-pressible Euler equation for two ideal gases.ρρuρvE…  相似文献   
616.
起落架缓冲系统参数优化设计   总被引:1,自引:0,他引:1  
刘莉  杨国柱  何庆芝 《航空学报》1992,13(10):506-511
 同时考虑了起落架缓冲系统性能对飞机着陆和滑行过程中的影响,从改善飞机地面滑行动态响应特性出发,在满足着陆撞击等约束条件下,提出并建立了起落架缓冲系统参数优化设计的方法和模型,并以主起落架缓冲系统优化设计为例,具体讨论了优化过程和结果。实例计算表明,利用本文方法将有效地改善起落架缓冲系统性能。  相似文献   
617.
介绍了用功率源法与分流法相结合对电流互感器校验仪进行检定的方法,并给出了检定结果的不确定度。该方法已应用于新研制的400Hz电流互感校验仪的检定,对于工频的电流互感器校验仪的检定也有一定的参考价值。  相似文献   
618.
A comprehensive observational sequence using the Deep Impact (DI) spacecraft instruments (consisting of cameras with two different focal lengths and an infrared spectrometer) will yield data that will permit characterization of the nucleus and coma of comet Tempel 1, both before and after impact by the DI Impactor. Within the constraints of the mission system, the planned data return has been optimized. A subset of the most valuable data is planned for return in near-real time to ensure that the DI mission success criteria will be met even if the spacecraft should not survive the comet’s closest approach. The remaining prime science data will be played back during the first day after the closest approach. The flight data set will include approach observations spanning the 60 days prior to encounter, pre-impact data to characterize the comet at high resolution just prior to impact, photos from the Impactor as it plunges toward the nucleus surface (including resolutions exceeding 1 m), sub-second time sampling of the impact event itself from the Flyby spacecraft, monitoring of the crater formation process and ejecta outflow for over 10 min after impact, observations of the interior of the fully formed crater at spatial resolutions down to a few meters, and high-phase lookback observations of the nucleus and coma for 60 h after closest approach. An inflight calibration data set to accurately characterize the instruments’ performance is also planned. A ground data processing pipeline is under development at Cornell University that will efficiently convert the raw flight data files into calibrated images and spectral maps as well as produce validated archival data sets for delivery to NASA’s Planetary Data System within 6 months after the Earth receipt for use by researchers world-wide.  相似文献   
619.
采用模糊集合理论来处理校准实验室质量体系的综合评判问题.描述了建立模糊评价模型的方法,并给出了实际的应用计算.  相似文献   
620.
线阵CCD器件主要性能参数及测试方法   总被引:5,自引:1,他引:5  
给出了星载遥感器所使用的线阵CCD器件的主要性能参数及其定义,提出一整套测试线阵CCD器件所需的测试设备、测试方法及其用于获得测试结果的计算公式。  相似文献   
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