低信噪比条件下无先验知识的信号检测问题是一类侦察问题。基于功率谱熵的分析算法是一种实际可行且有效的自动检测方法,但还没有建立相应的理论性能分析。针对白高斯噪声背景中检测未知正弦信号的问题描述,以统计理论分析功率谱熵检测...低信噪比条件下无先验知识的信号检测问题是一类侦察问题。基于功率谱熵的分析算法是一种实际可行且有效的自动检测方法,但还没有建立相应的理论性能分析。针对白高斯噪声背景中检测未知正弦信号的问题描述,以统计理论分析功率谱熵检测的接收机工作特性曲线(ROC),所得到的理论结果与仿真相比基本吻合。功率谱熵检测与能量检测的性能比较表明,功率谱熵检测性能明显优于后者。海试数据验证实际可检测的信噪比与理论预报相差不超过2 d B。展开更多
分布式拒绝服务(distributed denial of service,DDoS)攻击能够在短时间内产生巨量的数据包耗尽目标主机或网络的资源,经过研究发现这些伪造的数据包在一个特定的时间内有着合法数据包所不具备的函数特点。因此,本文提出了行为分布的模...分布式拒绝服务(distributed denial of service,DDoS)攻击能够在短时间内产生巨量的数据包耗尽目标主机或网络的资源,经过研究发现这些伪造的数据包在一个特定的时间内有着合法数据包所不具备的函数特点。因此,本文提出了行为分布的模型,一旦有可疑流流入服务器,则开始计算这些可疑流的行为分布差异,如果该差异小于一个设定的阈值,则判断有DDoS攻击发生;反之则为合法的数据访问。根据NS-3的模拟实验,证明该模型能够有效的从合法访问中区分出DDoS攻击流,对提前控制DDoS攻击的发生具有重要的意义。展开更多
This paper presents an algorithm of edge detection in image processing. A new entropy operator and threshold estimation technique are effectively proposed. The algorithm overcomes some drawbacks of Shiozaki operator. ...This paper presents an algorithm of edge detection in image processing. A new entropy operator and threshold estimation technique are effectively proposed. The algorithm overcomes some drawbacks of Shiozaki operator. It not only has higher speed but also can extract the edge better. Finally, an example of 2D image is given to demonstrate the usefulness and advantages of the algorithm.展开更多
Log volume inspection is very important in forestry research and paper making engineering. This paper proposed a novel approach based on computer vision technology to cope with log volume inspection. The needed hardwa...Log volume inspection is very important in forestry research and paper making engineering. This paper proposed a novel approach based on computer vision technology to cope with log volume inspection. The needed hardware system was analyzed and the details of the inspection algorithms were given. A fuzzy entropy based on image enhancement algorithm was presented for enhancing the image of the cross-section of log. In many practical applications the cross-section is often partially invisible, and this is the major obstacle for correct inspection. To solve this problem, a robust Hausdorff distance method was proposed to recover the whole cross-section. Experiment results showed that this method was efficient.展开更多
Based upon the maximum entropy theorem of information theory, a novel fuzzy approach for edge detection is presented. Firstly, a definition of fuzzy partition entropy is proposed after introducing the concepts of fu...Based upon the maximum entropy theorem of information theory, a novel fuzzy approach for edge detection is presented. Firstly, a definition of fuzzy partition entropy is proposed after introducing the concepts of fuzzy probability and fuzzy partition. The relation of the probability partition and the fuzzy c-partition of the image gradient are used in the algorithm. Secondly, based on the conditional probabilities and the fuzzy partition, the optimal thresholding is searched adaptively through the maximum fuzzy entropy principle, and then the edge image is obtained. Lastly, an edge-enhancing procedure is executed on the edge image. The experimental results show that the proposed approach performs well.展开更多
The heart rate variability could be explained by a low-dimensional governing mechanism. There has been increasing interest in verifying and understanding the coupling between the respiration and the heart rate. In thi...The heart rate variability could be explained by a low-dimensional governing mechanism. There has been increasing interest in verifying and understanding the coupling between the respiration and the heart rate. In this paper we use the nonlinear detection method to detect the nonlinear deterministic component in the physiological time series by a single variable series and two variables series respectively, and use the conditional information entropy to analyze the correlation between the heart rate, the respiration and the blood oxygen concentration. The conclusions are that there is the nonlinear deterministic component in the heart rate data and respiration data, and the heart rate and the respiration are two variables originating from the same underlying dynamics.展开更多
Detecting traffic anomalies is essential for diagnosing attacks. HighSp eed Backbone Net works （HSBN） require Traffic Anomaly Detection Systems （TADS） which are accurate （high detec tion and low false positive ra...Detecting traffic anomalies is essential for diagnosing attacks. HighSp eed Backbone Net works （HSBN） require Traffic Anomaly Detection Systems （TADS） which are accurate （high detec tion and low false positive rates） and efficient. The proposed approach utilizes entropy as traffic distributions metric over some traffic dimensions. An efficient algorithm, having low computational and space complexity, is used to estimate entro py. Entropy values over all dimensions are展开更多
文摘低信噪比条件下无先验知识的信号检测问题是一类侦察问题。基于功率谱熵的分析算法是一种实际可行且有效的自动检测方法,但还没有建立相应的理论性能分析。针对白高斯噪声背景中检测未知正弦信号的问题描述,以统计理论分析功率谱熵检测的接收机工作特性曲线(ROC),所得到的理论结果与仿真相比基本吻合。功率谱熵检测与能量检测的性能比较表明,功率谱熵检测性能明显优于后者。海试数据验证实际可检测的信噪比与理论预报相差不超过2 d B。
文摘分布式拒绝服务(distributed denial of service,DDoS)攻击能够在短时间内产生巨量的数据包耗尽目标主机或网络的资源,经过研究发现这些伪造的数据包在一个特定的时间内有着合法数据包所不具备的函数特点。因此,本文提出了行为分布的模型,一旦有可疑流流入服务器,则开始计算这些可疑流的行为分布差异,如果该差异小于一个设定的阈值,则判断有DDoS攻击发生;反之则为合法的数据访问。根据NS-3的模拟实验,证明该模型能够有效的从合法访问中区分出DDoS攻击流,对提前控制DDoS攻击的发生具有重要的意义。
文摘This paper presents an algorithm of edge detection in image processing. A new entropy operator and threshold estimation technique are effectively proposed. The algorithm overcomes some drawbacks of Shiozaki operator. It not only has higher speed but also can extract the edge better. Finally, an example of 2D image is given to demonstrate the usefulness and advantages of the algorithm.
文摘Log volume inspection is very important in forestry research and paper making engineering. This paper proposed a novel approach based on computer vision technology to cope with log volume inspection. The needed hardware system was analyzed and the details of the inspection algorithms were given. A fuzzy entropy based on image enhancement algorithm was presented for enhancing the image of the cross-section of log. In many practical applications the cross-section is often partially invisible, and this is the major obstacle for correct inspection. To solve this problem, a robust Hausdorff distance method was proposed to recover the whole cross-section. Experiment results showed that this method was efficient.
文摘Based upon the maximum entropy theorem of information theory, a novel fuzzy approach for edge detection is presented. Firstly, a definition of fuzzy partition entropy is proposed after introducing the concepts of fuzzy probability and fuzzy partition. The relation of the probability partition and the fuzzy c-partition of the image gradient are used in the algorithm. Secondly, based on the conditional probabilities and the fuzzy partition, the optimal thresholding is searched adaptively through the maximum fuzzy entropy principle, and then the edge image is obtained. Lastly, an edge-enhancing procedure is executed on the edge image. The experimental results show that the proposed approach performs well.
基金Scientific Research Foundation for the Returned Overseas Chinese Scholars of ChinaGrant number:20041764+1 种基金Natural Science Foundation of Shandong ProvinceGrant number:Z2004G01
文摘The heart rate variability could be explained by a low-dimensional governing mechanism. There has been increasing interest in verifying and understanding the coupling between the respiration and the heart rate. In this paper we use the nonlinear detection method to detect the nonlinear deterministic component in the physiological time series by a single variable series and two variables series respectively, and use the conditional information entropy to analyze the correlation between the heart rate, the respiration and the blood oxygen concentration. The conclusions are that there is the nonlinear deterministic component in the heart rate data and respiration data, and the heart rate and the respiration are two variables originating from the same underlying dynamics.
基金supported by the National High-Tech Research and Development Plan of China under Grant No.2011AA010702
文摘Detecting traffic anomalies is essential for diagnosing attacks. HighSp eed Backbone Net works （HSBN） require Traffic Anomaly Detection Systems （TADS） which are accurate （high detec tion and low false positive rates） and efficient. The proposed approach utilizes entropy as traffic distributions metric over some traffic dimensions. An efficient algorithm, having low computational and space complexity, is used to estimate entro py. Entropy values over all dimensions are
