低对比度图像特征点提取与匹配

针对常用特征点匹配算法在低对比度图像中存在特征点少、匹配精度低的问题,将图像自相似性用于图像特征点提取,并改进特征点匹配过程,提出了自相似性与改进归一化互相关相结合的方法.该方法首先根据像素点自对称值提取出图像特征点,然后通过特征点的尺度信息构建自适应相关窗口来改进互相关匹配,最后由阈值筛选和随机抽样一致性算法优化匹配结果,从而完成低对比度图像特征点的提取和匹配.实验结果表明,该方法在匹配低对比度图像特征点时相比常用算法具有较高的效率,且对图像尺度和旋转变换具有较强的鲁棒性.     

网络流量分析方法综述

了解网络流量的各种特性和分析方法可以更好的理解网络行为,规划和设计网络。通过对网络流量分析方法的研究,对该领域的关键概念和流量模型的工作原理、特点及应用范围的分析与比较,得出混合模型将成为未来流量预测研究的发展方向。     

自相似业务流复用特性分析

现有研究将复用的自相似业务流Hurst参数值确定为各个业务流中最大的H参数值，与业务流的其他性质无关，这一结论用于网络设备的设计不利于网络资源的有效利用。本文采用简单近似估算，并用分形布朗运动模型生成自相似业务流，彩用小波分析方法估计Hurst参数值。实验结果表明，由于复用合成业务流的渐近自相似的本质，在可以观测的时间尺度范围内业务流的Hurst参数比这理论预测值小；在一定的序列长度下，复用流的Hurst参数的不仅和最大Hurst参数业务流有关，还受到其它业务流，特别是业务流的方差系数所表现出的短时突发性影响，因此对合成业务流的自相似参数具有重要的影响。     

Another Cause of Long-Range Time Dependence

Cellular communicationnetworks satisfy the very conditions required to be complex adaptivesystems,so it is expected thatinteresting phenomenaproper to themcan be observed in their behaviors.In this paper,assuming three kinds of cellular networkssuch as CDMA, FCA-TDMA and DCA-TDMA networks,we examine their traffic intensity dynamicsby computer simulation.We show thatDCA-TDMA network has a hidden cause to producea long-range time dependence in its traffic intensity dynamics,so self-similarity appears there,regardless of property of traffic source andservice generation rate.Furthermore,we reveal that the cause is a strong interdependency amongcells through inter-cell interference.     

Characteristics of WAP Traffic

This paper considers the characteristics of Wireless Application Protocol (WAP) traffic. We start by constructing a WAP traffic model by analysing the behaviour of users accessing public WAP sites via a monitoring system. A wide range of different traffic scenarios were considered, but most of these scenarios resolve to one of two basic types. The paper then uses this traffic model to consider the effects of large quantities of WAP traffic on the core network. One traffic characteristic which is of particular interest in network dimensioning is the degree of self-similarity, so the paper looks at the characteristics of aggregated traffic with WAP, Web and packet speech components to estimate its self-similarity. The results indicate that, while WAP traffic alone does not exhibit a significant degree of self-similarity, a combined load from various traffic sources retains almost the same degree of self-similarity as the most self-similar individual source.     

Can Chaos Theory Explain Complexity In Urban Fabric? Applications in Traditional Muslim Settlements

The present work is a limited analysis of the traditional urban fabric of Muslim cities in the light of this theory. Chaos theory provides better instruments for the analysis and understanding of the traditional urban fabric in old Muslim cities that have, paradoxically, long been considered as lacking order and thus “chaotic” in the pejorative sense! Beyond the analysis, our study also aims at providing a fresh approach to the built environment that shifts the architectural and planning professions from the traditional design and planning approach to a self-generating process that, once set up, would function and develop without need for intervention. However, the present study will be limited to the application of such concepts at two levels. At the urban level, it will provide evidence of the existence of chaos and fractals at the scale of the city. At the domestic level, concepts are applied to housing evolution and community spaces.     

分形图案与花色设计

分形几何学为描述自然界中具有无规结构之复杂系统的形貌及结构特征提供了一个极为有效的工具．本文借助分形几何学中自相似性的概念，利用压缩变换法，在计算机上得到了具有自相似性特征的、美妙而富于变化的分形图案．本工作为印染图案和花色设计提供了新的构造方法．     

Emergence of genomic self-similarity in location independent representations

A key property for predicting the effectiveness of stochastic search techniques, including evolutionary algorithms, is the existence of a positive correlation between the form and the quality of candidate solutions. In this paper we show that when the ordering of genomic symbols in a genetic algorithm is completely independent of the fitness function and therefore free to evolve along with the candidate solutions it encodes, the resulting genomes self-organize into self-similar structures that favor this key stochastic search property.     

光突发交换网中的智能组包研究

光突发交换(OBS)相对传统的电路交换方式具有更高的传输效率和更短的网络时延,而相对于未来网络的发展趋势光分组交换,光突发交换具备更现实的可行性.在OBS中,突发汇聚是一个很关键的技术,它对OBS网络的性能有着重要的影响,在本文中,我们对突发汇聚机制进行了较深入的研究,并提出了一种新的突发汇聚算法,它对抑制网络流量的自相似性,提高突发传输效率和避免在不同节点由于突发同步所引起的带宽资源竞争都有较好的结果.     

网络自相似业务模型进展

综述了目前国内外在自相似业务建模研究方面所获得的主要成果，分析了各种模型的特点，并进行了分类和评价，指出了几种重要模型的参数获取的复杂度，并对模型的意义进行了初步的探讨，提出了有待进一步研究的问题，对自相似业务的分析和处理具有一定的指导意义。