Characterization of fuzzy clustering algorithms in terms of entropy of probabilistic sets

We discuss a method of evaluating fuzzy clustering algorithms. Each of them generates a partition matrix of a data set with the entries lying in the [0, 1] interval and expressing the grade of belonging of the object to the clusters detected. Membership functions of the same cluster are interpreted as probabilistic sets in the sense of Hirota. This makes it possible to characterize the clusters by means of the entropy of the corresponding probabilistic sets. Moreover, the mutual entropy of pairs of probabilistic sets provides an index for evaluating the degree of interaction between clusters.     

局部环上两个同阶幂等矩阵及其积在同一相似变换下的广义逆

设R是一个局部环,在R上同一相似变换下将单个矩阵的广义逆理论进行推广. 利用局部环上矩阵方法和同一相似变换下的矩阵标准形理论,研究了2个同阶幂等矩阵及其积的广义逆,得到了(1)2个幂等矩阵及其积在同一相似变换下的{k}-逆 (k=1,3);(2)2个幂等矩阵及其积在同一相似变换下的{i,j}-逆的表达式,其中i≠j.     

多尺度特征提取和多级别特征融合的显著性目标检测方法

显著性目标检测已经被广泛应用到图像检索、图像分割、行人重识别等领域.目前主流的显著性目标检测方法通常采用短连接加权的方式融合多级别特征信息,这种方式无法精准有效地控制信息流的传递.而且,现有的检测方法通常采用单一的特征检测,导致显著性目标区域与背景的边界不连续、易模糊.因此,本文提出一种多尺度特征提取和多级别特征融合的...     

一种大容量文本集的智能检索方法

分析了潜在语义模型,研究了潜在语义空间中文本的表示方法,提出了一种大容量文本集的检索策略。检索过程由粗粒度非相关剔除和相关文本的精确检索两个步骤组成。使用潜在语义空间模型对文本集进行初步的筛选,剔除非相关文本;使用大规模文本检索方法对相关文本在段落一级进行精确检索,其中为了提高检索的执行效率,在检索算法中引入了遗传算法;输出这些候选的段落序号。实验结果证明了这种方法的有效性和高效性。     

分层的文本信息隐藏研究

针对文本载体冗余度小的问题,提出一种在文本中分层隐藏信息的技术,建立了一个由待藏信息表示层、待藏信息加密层、载体内容层、载体内码层和载体版式层五个层次组成的隐藏模型.待藏信息表示层将待藏信息编码成不可读的符号序列,待藏信息加密层则对这些不可读符号序列进一步加密.载体内容层在句法、语义和语用上对前一层的输出进行嵌入隐藏,载体内码层和载体版式层分别通过选择载体文字自身的机器编码标准及版式来隐藏信息.每层有控制信息和数据信息作为参数,各层各司其职,高度独立.根据不同的隐藏要求,可以选择跳过某层,直接进入下层.介绍了各层的隐藏技术和方法,并在微软的Word文本中实现了该5层隐藏模型.     

基于EMD的融合特征快速多示例人脸识别算法

在基于五官模版技术的人脸识别中,因光照、角度及缺少整体性考虑等情况,易产生异常示例,影响了算法精度;而适合多示例检索的EMD测度寻优路径较长,导致在人脸识别中应用受限。为此本文提出了一种基于EMD测度的快速融合特征多示例人脸识别算法（IIFEMD-MIL）。针对异常点的问题,通过引入结合整体特征的融合多示例技术以及距离阀值,从而减少异常示例的产生并对超过阈值的示例予以平滑处理;针对寻优路径长的问题,将人脸五官之三结合整体示例为模版构建四示例的一一匹配,并进一步提出了融合快速EMD-MIL框架,缩短了寻优遍历路径。在ORL和MIT图像集上进行的比对实验表明,该算法执行效率和分类准确性优于其他同类算法。     

网络隐蔽通道检测系统模型设计

利用TCP／IP协议中建立隐蔽通道来进行非法通信已经成为网络安全的重要威胁。论文首先以IP协议和TCP协议为例,简要介绍了TCP／IP协议下网络隐蔽通道的建立方法和检测特点,针对目前检测工具主要面向特定隐蔽通道的特点,结合协议分析和流量分析方法提出了一种网络隐蔽通道检测系统的设计模型,为隐蔽通道的综合性检测提供了一种新的思路。     

A scalable and format-compliant encryption scheme for H.264/SVC bitstreams

SVC (Scalable Video Coding) is designed to adapt to heterogeneous networks and various terminal devices. This paper presents an encryption scheme for SVC bitstreams which retains the valuable scalability properties of SVC. To this end, we explore PACSI (Payload Content Scalability Information) and RTP (Real-time Transport Protocol) payload format such that encrypted bitstreams are SVC format-compliant. Specifically, the proposed scheme processes the base layer and enhancement layers in different ways. For the base layer, the scheme encrypts VCL (video coding layer) NALU (Network Abstract Layer Unit) into either SEI (Supplement Enhancement Information) NALU or PACSI NALU. For an enhancement layer, the scheme replaces a coded slice in scalable extension NALU with an encryption of PACSI NALU. Thus, the proposed encryption scheme preserves SVC scalability and format-compliance. It produces encrypted bitstreams which have the original SVC structure without emulation markers or illegal codewords for any standard decoder. The analysis and experiments indicate that our algorithm is cost-effective and secure against chosen plaintext attack.     

Polynomial time solution to minimum forwarding set problem in wireless networks under disk coverage model

In this paper, we consider a practical problem, called Minimum Forwarding Set Problem (MFSP), that emerges within the context of implementing (energy efficient) communication protocols for wireless ad hoc or sensor networks. For a given node v, MFSP asks for a minimum cardinality subset of 1-hop neighbors of v to cover v’s 2-hop neighbors. MFSP problem is also known as multi-point relay (MPR) problem. It is shown to be an NP-complete problem for its general case that does not consider the coverage characteristics of wireless transmissions. In this paper, we present two polynomial time algorithms to solve the MFSP problem under disk coverage model for wireless transmissions. In our earlier work, we presented a polynomial time algorithm for this problem under unit disk coverage model. In the current work, we present several observations on the geometric characteristics of wireless transmissions under disk coverage model and build two alternative dynamic programming based solutions with different run time and space complexities to the problem. Disk coverage model is a more general model because it allows nodes to use arbitrary power levels for transmissions. As a result, the presented algorithms provide a more practical solution that can be used as a building block for energy efficient communication protocols designed for wireless ad hoc and sensor networks.