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基于逆系统的墙壁补偿算法研究
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作者 崔国龙 孔令讲 杨建宇 《信号处理》 CSCD 北大核心 2009年第3期489-492,共4页
针对信号穿过墙壁产生折射、速度改变等问题,本文把墙壁近似看成线性可逆系统,通过分析目标信号的回波模型,推导出发射信号、目标参数和墙壁系统函数之间的关系,提出一种基于逆系统概念的墙壁补偿算法和墙壁系统函数估计方法。实验表明... 针对信号穿过墙壁产生折射、速度改变等问题,本文把墙壁近似看成线性可逆系统,通过分析目标信号的回波模型,推导出发射信号、目标参数和墙壁系统函数之间的关系,提出一种基于逆系统概念的墙壁补偿算法和墙壁系统函数估计方法。实验表明,该算法能够很好的补偿图像出现的散焦、位置偏移等影响。 展开更多
关键词 系统 系统函数估计 墙壁补偿算法
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Robust background subtraction in traffic video sequence 被引量:6
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作者 高韬 刘正光 +3 位作者 岳士弘 张军 梅建强 高文春 《Journal of Central South University》 SCIE EI CAS 2010年第1期187-195,共9页
For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background mod... For intelligent transportation surveillance, a novel background model based on Mart wavelet kernel and a background subtraction technique based on binary discrete wavelet transforms were introduced. The background model kept a sample of intensity values for each pixel in the image and used this sample to estimate the probability density function of the pixel intensity. The density function was estimated using a new Marr wavelet kernel density estimation technique. Since this approach was quite general, the model could approximate any distribution for the pixel intensity without any assumptions about the underlying distribution shape. The background and current frame were transformed in the binary discrete wavelet domain, and background subtraction was performed in each sub-band. After obtaining the foreground, shadow was eliminated by an edge detection method. Experimental results show that the proposed method produces good results with much lower computational complexity and effectively extracts the moving objects with accuracy ratio higher than 90%, indicating that the proposed method is an effective algorithm for intelligent transportation system. 展开更多
关键词 background modeling background subtraction Marr wavelet binary discrete wavelet transform shadow elimination
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Leak Detection in Water Distribution Systems Using Bayesian Theory and Fisher’s Law 被引量:1
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作者 张宏伟 王丽娟 《Transactions of Tianjin University》 EI CAS 2011年第3期181-186,共6页
A leak detection method based on Bayesian theory and Fisher’s law was developed for water distribution systems. A hydraulic model was associated with the parameters of leaks (location, extent). The randomness of para... A leak detection method based on Bayesian theory and Fisher’s law was developed for water distribution systems. A hydraulic model was associated with the parameters of leaks (location, extent). The randomness of parameter values was quantified by probability density function and updated by Bayesian theory. Values of the parameters were estimated based on Fisher’s law. The amount of leaks was estimated by back propagation neural network. Based on flow characteristics in water distribution systems, the location of leaks can be estimated. The effectiveness of the proposed method was illustrated by simulated leak data of node pressure head and flow rate of pipelines in a test pipe network, and the leaks were spotted accurately and renovated on time. 展开更多
关键词 water distribution systems LEAK DETECTION EPANET Fisher's law Bayesian theory back propagationneural network
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ITERATIVE QUASI-LIKELIHOOD FOR SEEMINGLY UNRELATED REGRESSION SYSTEMS
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作者 LINLU FANYUNZHENG +1 位作者 DUJUN YUANYUAN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2005年第3期335-346,共12页
In the seemingly unrelated regression systems, the existing quasi-likelihood is always involved in the difficult problem of calculating inverse of a high order matrix specially for large systems. To avoid this problem... In the seemingly unrelated regression systems, the existing quasi-likelihood is always involved in the difficult problem of calculating inverse of a high order matrix specially for large systems. To avoid this problem, the new quasi-likelihood proposed in this paper is based mainly on a linearly iterative process of some unbiased estimating functions.Some finite sample properties and asymptotic behaviours for this new quasi-likelihood are investigated. These results show that the new quasi-likelihood for parameter of interest is E-sufficient, iteratively efficient and approximately efficient. Some examples are given to illustrate the theoretical results. 展开更多
关键词 Seemingly unrelated regression system QUASI-LIKELIHOOD Unbiased estimating function
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