共查询到20条相似文献,搜索用时 15 毫秒
1.
Madiman M. Barron A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(7):2317-2329
New families of Fisher information and entropy power inequalities for sums of independent random variables are presented. These inequalities relate the information in the sum of n independent random variables to the information contained in sums over subsets of the random variables, for an arbitrary collection of subsets. As a consequence, a simple proof of the monotonicity of information in central limit theorems is obtained, both in the setting of independent and identically distributed (i.i.d.) summands as well as in the more general setting of independent summands with variance-standardized sums. 相似文献
2.
Binia J. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(3):1179-1182
Expressions for (entropy-power inequality (EPI) Shannon type) divergence-power inequalities (DPIs) in two cases (time-discrete and time-continuous) of stationary random processes are given. The new expressions connect the divergence rate of the sum of independent processes, the individual divergence rate of each process, and their power spectral densities. All divergences are between a process and a Gaussian process with same second-order statistics, and are assumed to be finite. A new proof of the Shannon EPI, based on the relationship between divergence and causal minimum mean-square error (CMMSE) in Gaussian channels with large signal-to-noise ratio, is also shown 相似文献
3.
基于最优分类系数及分类熵准则的模糊C均值聚类算法 总被引:1,自引:0,他引:1
本文分别以模糊分类系数和分类熵为聚类有效性的测度函数,采用模糊C均值分类法,求最优的测度函数值所代表的全局极值的那种分类,确定为最佳分类方,对一张由卫星拍摄的地面MIG-29型飞机照片进行了成功的分类试验。 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》2009,55(6):2537-2546
5.
Schonhuth A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2009,55(5):2119-2127
Entropy rate is a real valued functional on the space of discrete random sources for which it exists. However, it lacks existence proofs and/or closed formulas even for classes of random sources which have intuitive parameterizations. A good way to overcome this problem is to examine its analytic properties relative to some reasonable topology. A canonical choice of a topology is that of the norm of total variation as it immediately arises with the idea of a discrete random source as a probability measure on sequence space. It is shown that both upper and lower entropy rate, hence entropy rate itself if it exists, are Lipschitzian relative to this topology, which, by well known facts, is close to differentiability. An application of this theorem leads to a simple and elementary proof of the existence of entropy rate of random sources with finite evolution dimension. This class of sources encompasses arbitrary hidden Markov sources and quantum random walks. 相似文献
6.
Gemelos G.M. Weissman T. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(9):3994-4007
We study the entropy rate of pattern sequences of stochastic processes, and its relationship to the entropy rate of the original process. We give a complete characterization of this relationship for independent and identically distributed (i.i.d.) processes over arbitrary alphabets, stationary ergodic processes over discrete alphabets, and a broad family of stationary ergodic processes over uncountable alphabets. For cases where the entropy rate of the pattern process is infinite, we characterize the possible growth rate of the block entropy 相似文献
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With the aim to reduce disorder and improve efficiency, nodes in an ad hoc network run a self-organization scheme to cooperatively organize the network. Although metrics such as complexity or self-stability are commonly used for evaluation, to the best of our knowledge, none of them quantifies the efficiency to build and maintain an organization (order). We henceforth apply the notion of entropy to ad hoc type wireless networks facilitating a quantification of the internal organizational state generated by different self-organization schemes. Invoking node and link failure probabilities, we expose the dependency of the organizational state on the self-organization protocol of choice. 相似文献
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纸币扎把的识别是纸币处理一个关键环节.目前识别纸币扎把的方法有图像颜色识别法和图像噪声边沿法,两种方法都需要保证扎把颜色与背景色有较大的差异,而且计算复杂.提出了图像分块的图像熵计算方式来完成纸币捆中的扎把区域识别的新思路,放宽了条件,提高了识别速度. 相似文献
12.
Yaming Yu 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2009,55(8):3645-3650
Some entropy comparison results are presented concerning compound distributions on nonnegative integers. The main result shows that, under a log-concavity assumption, two compound distributions are ordered in terms of Shannon entropy if both the ldquonumbers of claimsrdquo and the ldquoclaim sizesrdquo are ordered accordingly in the convex order. Several maximum/minimum entropy theorems follow as a consequence. Most importantly, two recent results of Johnson (2008) on maximum entropy characterizations of compound Poisson and compound binomial distributions are proved under fewer assumptions and with simpler arguments. 相似文献
13.
《Multimedia, IEEE》1999,6(1):80-84
The accepted and much-repeated definition for DVD is digital versatile disc or digital video disc, depending on whom you ask. The words behind the letters are not the only things about DVD whose meaning depends on the respondent; you will also get a different answer regarding DVD's purpose and future depending on individual viewpoint. The author gives a brief history of DVD and considers DVD-ROM and DVD Video 相似文献
14.
Multimedia is variously and often ambiguously defined. While most people might accept a mix of voice, text and graphics, they might resist calling a live lecture on a titled work of art a multimedia presentation. On the other hand, many definitions focus entirely on technology: multimedia seems to be defined by the hardware required rather than by the user's experience. For example, despite the statement that any computer application that employs a video disk, images from a CD-ROM, uses high-quality sound, or uses high-quality video images on a screen may be termed a multimedia application, the author doubts that anyone would use the term multimedia for a computer application that merely plays a piece of music. She suggests a model of media objects that does not refer to technology or interactivity, but rather concentrates on the nature of the text. This model provides a useful basis for defining multimedia communication securely and unambiguously 相似文献
15.
现有基于网络报文流量信息的协议分析方法仅考虑报文载荷中的明文信息,不适用于包含大量密文信息的安全协议。为充分发掘利用未知规范安全协议的密文数据特征,针对安全协议报文明密文混合、密文位置可变的特点,该文提出一种基于熵估计的安全协议密文域识别方法CFIA(Ciphertext Field Identification Approach)。在挖掘关键词序列的基础上,利用字节样本熵描述网络流中字节的分布特性,并依据密文的随机性特征,基于熵估计预定位密文域分布区间,进而查找密文长度域,定位密文域边界,识别密文域。实验结果表明,该方法仅依靠网络数据流量信息即可有效识别协议密文域,并具有较高的准确率。 相似文献
16.
针对基于深度图的视点绘制中空洞填补时产生的图像失真问题,提出一种还原空洞区域可靠纹理的空洞填补方法。通过从临近的帧画面中提取有效信息还原真实的背景图像,用于新视点中背景区域的空洞填补。并通过区分前景和背景图像区域,对不同区域的空洞采取不同的填充方法,从而获得较为可靠和真实的填补效果。从实验结果来看,该方法获得的PSNR数据优于其他算法,并且与真实视点比较的结构相似度达到99.1%,比传统方法提高10%以上。 相似文献
17.
一种改进的基于熵的图像检索算法 总被引:5,自引:4,他引:1
利用信息熵可以有效的将图像颜色直方图特征降低到一维,但以往的基于信息熵的图像检索算法却没有考虑熵的对称特性,因此极易造成误检现象.基于此,文中提出了相应的改进算法,消除由于熵的对称性对图像检索效果造成的影响.试验结果证明改进的方法在进行图像检索时具有更强的鲁棒性,大大提高了图像检索效率. 相似文献
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Nilsson M. Kleijn W.B. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(7):2330-2341
Estimation of the differential entropy from observations of a random variable is of great importance for a wide range of signal processing applications such as source coding, pattern recognition, hypothesis testing, and blind source separation. In this paper, we present a method for estimation of the Shannon differential entropy that accounts for embedded manifolds. The method is based on high-rate quantization theory and forms an extension of the classical nearest-neighbor entropy estimator. The estimator is consistent in the mean square sense and an upper bound on the rate of convergence of the estimator is given. Because of the close connection between compression and Shannon entropy, the proposed method has an advantage over methods estimating the Renyi entropy. Through experiments on uniformly distributed data on known manifolds and real-world speech data we show the accuracy and usefulness of our proposed method. 相似文献
20.
LIUYan-su XIAYang XUHong-ru ZHOUDong YAODe-zhong 《中国电子科技》2005,3(1):72-74
By the means of computing approximate entropy (ApEn) of video-EEG from some clinical epileptic, ApEn of EEG with epileptiform discharges is found significantly different from that of EEG without epileptiforrn discharges, (p=0.002). Meanwhile, dynamic ApEn shows consistent change of EEG signal with discharges of epileptic waves inside. These results suggest that ApEn may be a useful tool for automatic recognition and detection of epileptic activity and for understanding epileptogenic mechanism. 相似文献