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电子邮件的预处理,在邮件智能分类系统中是必不可少的重要环节,预处理的效果直接影响到邮件分类器的构建和邮件分类的效果。对电子邮件的预处理主要指汉语自动分词技术。 相似文献
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详细介绍了应用Windows2000技术,实现安全电子邮件体系的基本过程,包括认证中心的建立与管理,数字证书的申请,以及安全电子邮件操作。 相似文献
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电子邮件智能分类的研究 总被引:1,自引:0,他引:1
目前,对于电子邮件的分类主要是手动的方法,比如可以将我们收到的邮件选中之后手动标志为重要邮件、公司邮件、业务邮件、资讯邮件、亲友邮件、同学邮件、休闲邮件,没有基本的自动分类方法,没有实现真正意义上的电子邮件智能分类.当前有些电子邮件系统具有过滤功能,也只是根据已有垃圾邮件地址进行简单拦截,也有些系统具有标签的功能,但并没有真正实现电子邮件的智能服务,基于以上情况,此课题使用机器学习的方法提出了邮件智能分美的设计与实现.设计一种智能分类邮件的算法,并将算法应用在邮件智能分类系统中. 相似文献
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通过研究Postfix相关原理技术,提出了在linux操作系统上搭建符合企业实际需求的电子邮件管理系统的一套解决方案。 相似文献
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针对两类常见的制造加工约束即对称性和重复性下的连续体拓扑优化问题,提出了将敏度值在每轮优化前的修正方法,该方法简单且易于编程实现,实现了对称性或重复性约束条件下连续体拓扑优化设计,通过数值算例对不同制造加工约束下的拓扑结果进行了分析对比,结果表明,研究方法具有可行性和有效性。 相似文献
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D. G. Milovzorov V. Kh. Yasoveev 《Optoelectronics, Instrumentation and Data Processing》2017,53(4):388-394
Issues of designing fluxgate magnetic gradiometers are considered. The areas of application of fluxgate magnetic gradiometers are determined. The structure and layout of a two-component fluxgate magnetic gradiometer are presented. It is assumed that the fluxgates are strictly coaxial in the gradiometer body. Elements of the classical approach to the mathematical modeling of the spatial arrangement of solids are considered. The bases of the gradiometer body and their transformations during spatial displacement of the gradiometer are given. The problems of mathematical modeling of gradiometers are formulated, basic mathematical models of a two-component fluxgate gradiometer are developed, and the mathematical models are analyzed. A computer experiment was performed. Difference signals from the gradiometer fluxgates for the vertical and horizontal position of the gradiometer body are shown graphically as functions of the magnitude and direction of the geomagnetic field strength vector. 相似文献
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对液氮泵在使用过程中机械密封的失效现象进行分析研究,参数核算,确定出失效的原因,由此确定出改造措施,在大庆天然气公司的液氮泵上应用,密封性能和使用寿命得到了提高,改善了工作环境,经济效益非常显著。同时也为解决易挥发性介质的密封问题提供了参考。 相似文献
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Khodabakhsh Saeedi Alfin Leo Rama B. Bhat Ion Stiharu 《Journal of Mechanical Science and Technology》2012,26(5):1439-1448
The free vibration of a circular plate with multiple perforations is analyzed by using the Rayleigh-Ritz method. Admissible functions are assumed to be separable functions of radial and tangential coordinates. Trigonometric functions are assumed in the circumferential direction. The radial shape functions are the boundary characteristic orthogonal polynomials generated following the Gram-Schmidt recurrence scheme. The assumed functions are used to estimate the kinetic and the potential energies of the plate depending on the number and the position of the perforations. The eigenvalues, representing the dimensionless natural frequencies, are compared with the results obtained using Bessel functions, where the exact solution is available. Moreover, the eigenvectors, which are the unknown coefficients of the Rayleigh-Ritz method, are used to present the mode shapes of the plate. To validate the analytical results of the plates with multiple perforations, experimental investigations are also performed. Two unique case studies that are not addressed in the existing literature are considered. The results of the Rayleigh-Ritz method are found to be in good agreement with those from the experiments. Although the method presented can be employed in the vibration analysis of plates with different boundary conditions and shapes of the perforations, circular perforations that are free on the edges are studied in this paper. The results are presented in terms of dimensionless frequencies and mode shapes. 相似文献
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Yu. I. Sazonov 《Russian Journal of Nondestructive Testing》2006,42(12):823-836
Features of electron-beam welding (EBW), various types of flaws arising in welded joints during EBW, and the factors causing these flaws’ appearance are considered. The effects of beam focusing and the thickness of the welded metals on the shape of a seam are demonstrated. EBW flaws are classified. The difficulties associated with obtaining informative parameters during EBW are analyzed. Radiation and acoustic methods for engineering diagnostics of EBW are considered. New approaches to the construction of systems for diagnostics of EBW are proposed. Experimental results are presented. 相似文献
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基于活动标架法的二自由度机器人操作性能分析 总被引:1,自引:0,他引:1
用活动标架法研究了二自由度机器人机构的运动学 ,得出了机器人机构的一些不变量 ,并根据它们定义了机器人的平移体积、旋转体积、可操作性指标和灵活度 ,用这些指标评价机器人的操作性能。并由此得出了机器人产生奇异的条件 ,研究了工作空间曲面和奇异曲面的几何性质 ,计算了它们的法曲率和高斯曲率 相似文献
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铜合金表面激光熔覆研究现状 总被引:1,自引:0,他引:1
为了提高铜合金的表面耐磨性能,激光熔覆技术已被用于铜合金的表面处理;总结了铜合金表面激光熔覆的特点,评述了铜合金表面熔覆材料体系的研究现状和激光熔覆技术工艺,分析了熔覆层的表面性能,阐明了铜合金表面激光熔覆存在的主要问题和相应改进途径,并提出了今后的研究方向。 相似文献