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在网络信息搜索过程中会经常出现大量垃圾信息,这些垃圾信息,提高了用户查询有效信息的难度,浪费了用户查询有效信息的时间。本文提出一种利用行为模式识别技术,对网络搜索引擎获得信息结果进行过滤的方式,通过这种方式来提高网络搜索信息的准确率。 相似文献
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具有字符过滤功能的包过滤防火墙的设计研究 总被引:1,自引:0,他引:1
一、绪论传统的包过滤防火墙系统主要是包过滤规则以IP信息包为基础,对IP源地址、IP目标地址、封装协议(TCP/UDP)、端口号等进行筛选。只有符合访问条件的数据包才被转发,其它包被丢弃。其功能设计主要是为在IP层和传输层上进行过滤的,而内容过滤在传统的包过滤防火墙上是难 相似文献
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采用了模糊神经网络模型,对柴油机缸套磨损故障以及缸套破坏性磨损故障进行了诊断研究.通过缸套磨损故障的模拟实验,获取柴油机机身振动和铁谱分析等多源多雏故障信息,并对融合故障信息进行预处理,解决了模糊神经网络输入矢量的模糊特性化、输出矢量的隶属函数及网络的学习训练问题,对缸套不同磨损故障进行了诊断.研究表明,这种基于多信息的诊断方法减小了故障诊断的不确定性,提高了诊断精度. 相似文献
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如今我们的企业所使用的工程机械多数都采用了机、电、液一体化的技术,而液压系统的技术状况的好坏是整个工程机械技术状况好坏的关键。液压系统的作用是通过压强的改变增大作用力。一个完整的液压系统是由五个部分构成,即执行元件、动力元件、辅助元件、控制元件和液压油。系统设计合理性、系统污染处理与防护、系统元件性能优劣决定了一个液压系统的好坏。而系统污染处理与防护尤为重要。近年来我国国内的液压技术已经有了很大的提高,不再是使用国外的液压技术完成工程机械的加工。本文将针对工程机械液压油污染问题的来源和危害.对液压油过滤技术展开探讨。 相似文献
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随着通讯时代的到来,短信已成为人们生活中必不可少的工具之一,但是随之而来的垃圾短信,给人们的生活、工作带来一定烦恼,垃圾短信逐渐成为社会公害,需引起关注,将对当前垃圾短信的现状进行分析,并提出垃圾短信的过滤技术与解决方案,以净化通讯环境。 相似文献
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目前,90%的医药产品生产厂商都要利用活性炭清除杂质和异昧。但与此同时,如何将这些极为细小的活性炭粉末从最终成品中清理出去则成为一个生产过程的遗留问题。本文将向您介绍一种以深层过滤为基础的活性炭过滤方法,为您解决生产中的难题。 相似文献
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一种自适应的图像双边滤波方法 总被引:15,自引:0,他引:15
提出一种利用双边滤波的图像平滑滤波方法,即在滤除图像中高频噪声的同时,按照图像亮度变化保持图像中处于高频部分的边缘信息的自适应滤波过程。该滤波方法将传统的Gauss滤波器的权系数优化成Gauss函数和图像的亮度信息乘积的形式,优化后的权系数再与图像作卷积运算。这样,滤波时就可以考虑到图像的亮度信息,在滤除图像噪声的同时尽量保持了图像的边缘。由于双边滤波的方法可以使滤波器的权系数随着图像的亮度变化而改变,所以在滤波过程中能达到自适应滤波的目的。 相似文献
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The existing literature on supply chain information sharing assumes that information is shared truthfully. Unless each party can verify the authenticity of the other party's information, manufacturers and retailers may divulge false information for their own benefit. These information distortions may reduce the benefit levels or even stop information sharing in supply chains. We analyze the incentives for manufacturers and retailers within a supply chain to distort information when they share it and propose a mechanism that results in truthful information sharing. We consider a make-to-order supply chain consisting of a single manufacturer and a single retailer. The manufacturer and the retailer set prices based on their private forecasts of uncertain demand. If both parties share their forecasts truthfully, the manufacturer always benefits; however, the retailer benefits only if the manufacturer sets a lower wholesale price when information is shared compared to when information is not shared. However, we show that the manufacturer and the retailer, respectively, have an incentive to overstate and understate their forecasts while sharing information. The information distortion phenomenon is the direct result of each party exploiting its private information to appropriate the gains from information sharing. We show that the incentives to distort information are eliminated and both parties benefit from information sharing if the manufacturer and the retailer can agree on their relative profit margins prior to information sharing. 相似文献
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Application of stochastic filtering for lifetime prediction 总被引:1,自引:0,他引:1
This paper introduces a stochastic filtering modeling approach for predicting the remaining lifetime of a component based on information on the stochastic degradation process and uncertain condition monitoring measurements. The model is illustrated by a case study, where the degradation is assumed to be a simplified fatigue crack growth process. The model accounts for uncertainties in both degradation process and condition measurements in a sound way. If completed with information on costs of monitoring, failure and replacement, such model could be used in optimizing both the condition monitoring intervals and, e.g. the replacement time for the component. 相似文献
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在使用Shack-Hartmann传感器进行大口径非球面镜面检测中,外部环境的各种振动影响以及气流、温差的干扰都会使检测精度下降。针对这个问题,提出了一种新的时域小波滤波技术。这项技术可以对传感器的信号干扰在时间域上进行不同层次的小波分析,提取干扰信号的先验特征,对测量数据进行有效的滤波,减小波前的扰动起伏,以更准确地探测质心。实验结果表明,采用这种技术后,Shack-Hartmann波前传感器对光学镜面检测的静态测量精度提高了50%以上,离散性减少到原来的20%-30%。 相似文献
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Han‐Gyu Kim Gil‐Jin Jang Jeong‐Sik Park Ji‐Hwan Kim Yung‐Hwan Oh 《International journal of imaging systems and technology》2013,23(1):64-70
This article proposes a novel speech and sound segregation framework incorporating a technique for correcting a series of pitch periods based on particle filtering. The conventional pitch track correction method finds the peak locations of the autocorrelation functions to estimate the pitch period, and only the longest reliable pitch streak is used to correct unreliable pitch tracks. Especially in noisy environments, it is hard to find long and reliable pitch streaks, resulting in the degradation of the speech segregation performance. The proposed algorithm based on particle filtering considers all the reliable pitch streaks rather than the longest one and smoothly connects the scattered pitch streaks. To apply the particle filtering algorithm to pitch track correction, the importance weight computation to account for the degree of matchness of the found pitch to the individual spectro‐temporal components is also proposed. The performance of the proposed method is evaluated by the results of speech segregation experiments for the mixtures of speech and various noise sources in various mixing signal‐to‐noise ratios (SNRs). The evaluation measures were SNR, energy loss ratio, and noise residue ratio of the segregated speech, and all these measures showed that the proposed segregation method achieved superior performance compared to the conventional approach. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 64–70, 2013. 相似文献
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Bilateral filtering for structural topology optimization 总被引:1,自引:0,他引:1
Michael Yu Wang Shengyin Wang 《International journal for numerical methods in engineering》2005,63(13):1911-1938
Filtering has been a major approach used in the homogenization‐based methods for structural topology optimization to suppress the checkerboard pattern and relieve the numerical instabilities. In this paper a bilateral filtering technique originally developed in image processing is presented as an efficient approach to regularizing the topology optimization problem. A non‐linear bilateral filtering process leads to a suitable problem regularization to eliminate the checkerboard instability, pronounced edge preserving smoothing characteristics to favour the 0–1 convergence of the mass distribution, and computational efficiency due to its single pass and non‐iterative nature. Thus, we show that the application of the bilateral filtering brings more desirable effects of checkerboard‐free, mesh independence, crisp boundary, computational efficiency and conceptual simplicity. The proposed bilateral technique has a close relationship with the conventional domain filtering and range filtering. The proposed method is implemented in the framework of a power‐law approach based on the optimality criteria and illustrated with 2D examples of minimum compliance design that has been extensively studied in the recent literature of topology optimization and its efficiency and accuracy are highlighted. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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小波变换与卡尔曼滤波结合的RLG降噪方法 总被引:3,自引:1,他引:3
针对激光陀螺随机游走噪声其非平稳和非正态分布的特性,提出了基于小波变换的卡尔曼滤波的RLG降噪方法,该方法既具有小波变换对自相似过程的去相关作用和多分辨分析的功能,同时又保持了卡尔曼滤波器对未知信号的线性无偏最小方差估计的特点,实现了激光陀螺随机游走噪声的实时多尺度分解和最优估计。实测激光陀螺零偏信号去噪的结果表明,基于小波变换的卡尔曼滤波器使随机游走噪声的标准差降低了10.3%,降噪效果优于传统的卡尔曼滤波器。 相似文献