共查询到20条相似文献,搜索用时 15 毫秒
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In constructing an observer for a discrete-time nonlinear system, the system is commonly required to satisfy a certain kind of "uniform" observability condition, that is, the state should always be reconstructible from observation windows of a specific length, irrespective of the values of the state and inputs. In this technical note, it is proved that this "uniform" requirement is unnecessary in the sense that if the initial state and inputs are on a compact set, then the "uniform" observability is derived from its non-uniform counterpart. 相似文献
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本文提出了一个端到端的安全移动商务方案,它是基于J2ME并采周密钥动态更新的快速混沌加密技术而、实现的。针对混沌序列的特点,本文提出密钥生成与加密过程分离;对软件实现的有限字长效应,采用了两次反馈混沌加密。一个实例证实了本文的方案。 相似文献
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《Neural Networks, IEEE Transactions on》2008,19(8):1494-1495
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This letter describes an attack on the recently proposed ldquowatermarking method based on significant difference of wavelet coefficient quantizationrdquo by Lin While the method is shown to be robust against many signal processing operations, security of the watermarking scheme under intentional attack exploiting knowledge of the implementation has been neglected. We demonstrate a straightforward attack which retains the fidelity of the image. The method is therefore not suitable for copyright protection applications. Further, we propose a countermeasure which mitigates the shortcoming. 相似文献
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《Neural Networks, IEEE Transactions on》2009,20(8):1363-1367
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Huixia Liu Keyi Xing Song Gao 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2009,39(6):1348-1350
It was claimed recently in the paper by Li and Zhou that ldquoa polynomial time algorithm for finding the set of elementary siphons in S3PRs is proposed, which avoids complete siphon enumerationrdquo. However, this is incorrect because Proposition 1 and Corollary 6 of the aforementioned paper, which lead to the claim, are both incorrect. In this correspondence paper, Proposition 1 and Corollary 6 are disproved. As a consequence, some claims of the aforesaid paper are denied. Two examples are presented to disprove some claims of the previously mentioned paper. 相似文献
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Remarks on “Measuring Ambiguity in the Evidence Theory” 总被引:1,自引:0,他引:1
Klir G.J. Lewis H.W. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2008,38(4):995-999
In a recent paper, a functional AM (ambiguity measure) is introduced and an attempt is made to show that this functional qualifies as a measure of total aggregated uncertainty in the Dempster-Shafer theory. We show that this attempt fails due to a particular error in the proof of one of the principal theorems in the paper. Some additional remarks are made regarding recent research pertaining to the subject of the discussed paper. 相似文献
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A “Globally” Convergent Controller for Multi-Machine Power Systems Using Structure-Preserving Models
Dib W. Ortega R. Barabanov A. Lamnabhi-Lagarrigue F. 《Automatic Control, IEEE Transactions on》2009,54(9):2179-2185
The design of excitation controllers to improve transient stabilization of power systems is a topic of renewed interest in the control community. Existence of a state-feedback stabilizing law for multi-machine aggregated reduced network models has recently been established. In this paper we extend this result in two directions: first, in contrast with aggregated models, we consider the more natural and widely popular structure-preserving models that preserve the identity of the network components (generators, loads and lines) and allow for a more realistic treatment of the loads. Second, we explicitly compute a control law that, under a detectability assumption, ensures that all trajectories converge to the desired equilibrium point, provided that they start and remain in the region where the model makes physical sense. 相似文献
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《Neural Networks, IEEE Transactions on》2009,20(3):540-541
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In the recent paper by Cetinkaya et al , admission control tests are derived by approximating the sum of two Gumbel distributed random variables by a Gumbel distributed random variable. In fact, the sum of two Gumbel distributed random variables does not follow a Gumbel distribution. Here, explicit expressions are derived for the probability density function (pdf) and the cumulative distribution function (cdf) of the exact distribution of the sum. The discrepancy between the exact and the approximate distributions is studied numerically. 相似文献
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Van-Nam Huynh Nakamori Y. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2010,40(1):205-209
In a recent paper, Liu have proposed the so-called F -algorithm which conditionally reduces the computational complexity of the Meyerowitz-Richman-Walker algorithm for the computation of the aggregate-uncertainty measure in the Dempster-Shafer theory of evidence, along with an illustration of its application in a practical scenario of target identification. In this correspondence, we will point out several technical mistakes, which some of them lead to some inexact or incomplete statements in the paper of Liu The corrections of these mistakes will be made, and some further improvement and results will be derived. 相似文献
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由于图像隐写所引起的各种统计特征变化是不确定的,文中将Vague集相似度量引人隐写系统的安全性评价中.从图像的一阶统计特征和二阶统计特征两方面,定义了基于载体数据及载密数据相关Vague集相似度量的隐写系统一阶和二阶安全性测度,证明了该安全性测度的有界性,对称性和一致性.在假设图像满足独立同分布的条件下,证明了所提出的两种安全性测度是等价的.结果表明,所提出的二阶安全性比一阶安全性能更好地反映隐写引起的载体统计分布变化.与确定模式下的安全性测度相比,当嵌入率低于0.5比特/像素,新的测度可更好地度量隐写系统安全性,因此该测度对小容量的隐写及隐写分析算法设计具有更好的指导作用. 相似文献
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该文基于分布式系统给出了一种安全广播方案。与已有广播方案相比,该方案有效地减少了发送者所产生的广播信息并能防止攻击;另外,当一个新用户/已有用户要插入/退出分布式系统时,该方案不需要修改任何已有的保密密钥和公开密钥。 相似文献
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在分析图像盲检测算法原理的基础上,提出了一种在形态小波高频系数上进行消息嵌入的抗盲检测隐写算法.该算法利用五株采样提升实现图像的小波变换,在大于一定门限的小波高频系数中嵌入消息,并通过建立的嵌入信息表来修正嵌入规则以保持小波系数直方图近似不变,在门限处引入直方图调整策略以减小系数直方图在门限处的变化.由于通用盲检测算法大多基于概率密度函数的变化实现图像隐写的检测,因此本文算法可以获得对通用盲检测算法的抵抗能力.实验结果表明,本文算法在抵抗小波高阶统计量分析、直方图特征函数质心等盲检测算法能力方面,优于LSB匹配、像素值差分等隐写算法. 相似文献
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《Robotics, IEEE Transactions on》2009,25(2):475-475
In the above titled paper (ibid., vol. 24, no. 3, pp. 527-536, Jun 08), it is stated in Sec. IV-D3 that the characteristic number of the first variant of the "god object" method applied to texture synthesis is 1. This statement is not always true, and clarification of this issue is presented here. 相似文献
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Weisheng Chen 《Neural Networks, IEEE Transactions on》2009,20(5):897-898
The purpose of this comment is to point out some mistakes in the above paper. It is shown that the main results of the paper cannot stand in general. Also, it is pointed out that after some corrections, the proposed control algorithm is still applicable to a more simple system. For simplicity, all the symbols in this comment are the same as those in the above paper. 相似文献