Attack Vulnerability of Network with Duplication-Divergence Mechanism

We study the attack vulnerability of network with duplication-divergence mechanism. Numerical results have shown that the duplication-divergence network with larger retention probability a is more robust against target attack relatively. Furthermore, duplication-divergence network is broken down more quickly than its counterpart BA network under target attack. Such result is consistent with the fact of WWW and Internet networks under target attack. So duplication-divergence model is a more realistic one for us to investigate the characteristics of the world wide web in future. We also observe that the exponent γ of degree distribution and average degree are important parameters of networks, reflecting the performance of networks under target attack. Our results are helpful to the research on the security of network.     

Analyzing mechanism-based attacks in privacy-preserving data publishing

Privacy-preserving data publishing (PPDP) deals with data publishing while preserving individual's privacy in the data. Recent researches show that knowledge of mechanism of anonymization provides a loophole for attacks [1], [2], we call this kind of attack a mechanism-based attack. In this paper, we first give a comprehensive study of mechanism-based attack and point out that the range of mechanism-based disclosure is much broader than ever said. Then, we analyze the rationale of mechanism-based attack and give the definition of mechanism-based attack formally. To counteract mechanism-based attack, we introduce a model called e-secrecy and corresponding solution algorithm MAIA. We conduct a comprehensive set of experiments to show mechanism-based attacks are practical concern in the real-world data sets and that our method introduces better data utility and very minor computation than the existing algorithms.     

Nonlinear Dynamical Behavior in Neuron Model Based on Small World Network with Attack and Repair Strategy

In this paper, we investigate the effect due to the change of topology structure of network on the nonlinear dynamical behavior, by virtue of the OFC neuron evolution model with attack and repair strategy based on the small world. In particular, roles of various parameters relating to the dynamical behavior are carefully studied and analyzed. In addition, the avalanche and EEC-like wave activities with attack and repair strategy are also explored in detail in this work.     

Modeling Evolution of Weighted Clique Networks

We propose a weighted clique network evolution model, which expands continuously by the addition of a new clique (maximal complete sub-graph) at each time step. And the cliques in the network overlap with each other. The structural expansion of the weighted clique network is combined with the edges' weight and vertices' strengths dynamical evolution. The model is based on a weight-driven dynamics and a weights' enhancement mechanism combining with the network growth. We study the network properties, which include the distribution of vertices' strength and the distribution of edges' weight, and find that both the distributions follow the scale-free distribution. At the same time, we also find that the relationship between strength and degree of a vertex are linear correlation during the growth of the network. On the basis of mean-field theory, we study the weighted network model and prove that both vertices' strength and edges' weight of this model follow the scale-free distribution. And we exploit an algorithm to forecast the network dynamics, which can be used to reckon the distributions and the corresponding scaling exponents. Furthermore, we observe that mean-field based theoretic results are
consistent with the statistical data of the model, which denotes the theoretical result in this paper is effective.     

多个子玻色-爱因斯坦凝聚气体膨胀叠加形成的量子涡旋现象研究

基于二维模型,研究了多个子玻色-爱因斯坦凝聚气体在谐振势阱内膨胀叠加形成的量子涡旋现象.运用传播子方法,分析了对称分布的三个子玻色-爱因斯坦凝聚气体膨胀叠加形成宏观量子涡旋的物理过程,得到量子涡旋随时间演化的规律;发现涡旋核分布在谐振势阱内出现振荡;涡旋与反涡旋随时间演化而相互转变,并对这些现象进行了物理分析.     

Chosen-plaintext attack on lensless double-random phase encoding in the Fresnel domain

We demonstrate a method of chosen-plaintext attack on lensless double-random phase encoding (L-DRPE) in the Fresnel domain. With this attack an opponent can access two encryption keys with help of the impulse functions as chosen plaintexts. This shows that a lensless optical encryption scheme based on DRPE is vulnerable to chosen-plaintext attack. Cryptoanalysis also indicates that the security worry originates from the linearity of the encryption and decryption mechanism of the L-DRPE scheme. One of the interesting features of the proposed attack is that the decryption process is lossless. Numerical simulations show good agreement with theoretical analysis.     

Emergence of modularity and disassortativity in protein-protein interaction networks

In this paper, we present a simple evolution model of protein-protein interaction networks by introducing a rule of small-preference duplication of a node, meaning that the probability of a node chosen to duplicate is inversely proportional to its degree, and subsequent divergence plus nonuniform heterodimerization based on some plausible mechanisms in biology. We show that our model cannot only reproduce scale-free connectivity and small-world pattern, but also exhibit hierarchical modularity and disassortativity. After comparing the features of our model with those of real protein-protein interaction networks, we believe that our model can provide relevant insights into the mechanism underlying the evolution of protein-protein interaction networks.     

Rank-based model for weighted network with hierarchical organization and disassortative mixing

In this paper, we study a rank-based model for weighted network. The evolution rule of the network is based on the ranking of node strength, which couples the topological growth and the weight dynamics. Analytically and by simulations, we demonstrate that the generated networks recover the scale-free distributions of degree and strength in the whole region of the growth dynamics parameter (α>0). Moreover, this network evolution mechanism can also produce scale-free property of weight, which adds deeper comprehension of the networks growth in the presence of incomplete information. We also characterize the clustering and correlation properties of this class of networks. It is showed that at α=1 a structural phase transition occurs, and for α>1 the generated network simultaneously exhibits hierarchical organization and disassortative degree correlation, which is consistent with a wide range of biological networks.     

Degree distribution and robustness of cooperative communication network with scale-free model

With the requirements of users enhanced for wireless communication,the cooperative communication will become a development trend in future.In this paper,a model based on complex networks with both preferential attachment is researched to solve an actual network CCN(Cooperative Communication Network).Firstly,the evolution of CCN is given by four steps with different probabilities.At the same time,the rate equations of nodes degree are presented to analyze the evolution of CCN.Secondly,the degree distribution is analyzed by calculating the rate equation and numerical simulation.Finally,the robustness of CCN is studied by numerical simulation with random attack and intentional attack to analyze the effects of degree distribution and average path length.The results of this paper are more significant for building CCN to programme the resource of communication.     

A Topological Glass

We propose and study a model with glassy behavior. The state space of the model is given by all triangulations of a sphere with n nodes, half of which are red and half are blue. Red nodes want to have 5 neighbors while blue ones want 7. Energies of nodes with other numbers of neighbors are supposed to be positive. The dynamics is that of flipping the diagonal of two adjacent triangles, with a temperature dependent probability. We show that this system has an approach to a steady state which is exponentially slow, and show that the stationary state is unordered. We also study the local energy landscape and show that it has the hierarchical structure known from spin glasses. Finally, we show that the evolution can be described as that of a rarefied gas with spontaneous generation of particles and annihilating collisions.     

Dynamics of organizational rumor communication on connecting multi-small-world networks

We study the dynamics of an epidemic-like model for the spread of a rumor on a connecting multi-small-world-network (CM-SWN) model, which represents organizational communication in the real world. It has been shown that this model exhibits a transition between regimes of localization and propagation at a finite value of network randomness. Here, by numerical means, we perform a quantitative characterization of the evolution in the three groups under two evolution rules, namely the conformity and obeying principles. The variant of a dynamic CM-SWN, where the quenched disorder of small-world networks is replaced by randomly changing connections between individuals in a single network and stable connection by star nodes between networks, is also analysed in detail and compared with a mean-field approximation.     

A numerical model of the evolution of sand saltation with consideration of two feedback mechanisms

Saltation is one of the important transport modes in the movement of wind-blown grains. Its evolution was considered to be a wind-particle self-regulating process. Recent researches indicate that the particle mid-air collision greatly influences the sand movement, thus the mid-air collision mechanism may highly contribute to the evolution of wind-sand flow. A theoretical model is suggested to mathematically describe the evolution of wind-sand flow by considering the exiting wind-particle feedback mechanism as well as the particle mid-air collision mechanism. Based on this model, the time of the entire process to reach a steady state, the variation curves of the sand transport rate with time and the mid-air collision probability with time are calculated. The results show that the mid-air collision mechanism also contributes significantly to the stabilization of the saltation process.     

Characteristic of microstructured optical fibers: an analytical approach

We have recently developed a simple analytical model to study propagation characteristics of microstructured optical fibers (MOFs). We have used this model to study splice losses between two MOFs and also between an MOF and a conventional fiber. We have also presented here the results on evolution of fundamental mode from near-field to far-field, the effective mode area and the beam divergence using this model. Comparisons with available experimental and modeling results have also been included.     

Dynamics of organizational rumor communication on connecting multi-small-world networks

We study the dynamics of an epidemic-like model for the spread of a rumor on a connecting multi-small-world-network (CM-SWN) model, which represents organizational communication in the real world. It has been shown that this model exhibits a transition between regimes of localization and propagation at a finite value of network randomness. Here, by numerical means, we perform a quantitative characterization of the evolution in the three groups under two evolution rules, namely the conformity and obeying principles. The variant of a dynamic CM-SWN, where the quenched disorder of small-world networks is replaced by randomly changing connections between individuals in a single network and stable connection by star nodes between networks, is also analysed in detail and compared with a mean-field approximation.     

Studying invisible axion models at high temperature

During the thermal evolution of the universe, symmetry of the vacuum state in the presence of quantum fields should have changed at various stages. A possible indication of this effect on the DFSZ invisible axion model of the Peccei-Quinn CP conserving mechanism is presented here. To start with, the background theory of this mechanism in the cosmic evolution has been fully reviewed, as well as the leading cosmological arguments setting limits on the mass and coupling of such a particle. The CP conserving lagrangian of the invisible axion model also includes instanton gauge field configurations. In our opinion, these configurations could behave non trivially while decreasing the temperature as a consequence of the vacuum symmetry modifications. The interplay between symmetry modifications and cosmic evolution may thus lead to yet unclear effects. In fact, the model considered here is really quite a baby version of the real world, so that only preliminary indications and bare consistency arguments have been done from it. Nevertheless, the underlying idea, a possible neutral Higgs fields approximate resonance condition, seems to survive even in more sophisticated models.     

Cascading failure in Watts-Strogatz small-world networks

In this paper, we study the cascading failure in Watts-Strogatz small-world networks. We find that this network model has a heterogeneous betweenness distribution, although its degree distribution is homogeneous. Further study shows that this small-world network is robust to random attack but fragile to intentional attack, in the cascading failure scenario. With comparison to standard random graph and scale-free networks, our result indicates that the robust yet fragile property in the cascading failure scenario is mainly related to heterogeneous betweenness, rather than the network degree distribution. Thus, it suggests that we have to be very careful when we use terms such as homogeneous network and heterogeneous network, unless the distribution we refer to is specified.     

结合实际刻蚀数据的离子刻蚀产额优化建模方法

刻蚀表面仿真是研究等离子体刻蚀工艺过程机理的重要手段.在刻蚀表面仿真方法中,刻蚀表面演化模型和离子刻蚀产额模型直接决定了刻蚀表面演化结果.但现有的刻蚀表面演化模型不够精确,且目前离子刻蚀产额模型主要来自分子动力学仿真和物理实验,而实际加工过程十分复杂,等效的离子刻蚀产额包含很多因素.针对这些问题,首先对当前的刻蚀表面演化模型进行改进,同时重新定义了离子刻蚀产额模型的优化目标,并利用实际刻蚀加工数据来优化离子刻蚀产额模型.为缩短优化模型所用时间,采用并行方法来加速优化过程.最后,将得到的离子刻蚀产额模型参数应用于采用元胞自动机法的刻蚀工艺实际仿真过程中.实验结果表明,该优化建模方法确实提高了仿真的精确度,同时优化过程所用时间也大大减少.     

基于压缩表示的离子刻蚀仿真三维表面演化方法

为了研究表面演化过程的机理, 提出了一种基于压缩表示的三维表面演化方法来模拟等离子体刻蚀工艺,并着重探讨了对离子刻蚀的仿真. 为了解决三维元胞自动机内存需求量大的问题, 该方法将二维数组和动态存储方式相结合, 既实现元胞信息的无损压缩存储, 又保持三维元胞间的空间相关性. 实验结果也表明该方法不仅节省了大量内存, 而且在高分辨率条件下查找离子初始碰撞的表面元胞效率较高, 满足高分辨率仿真的要求. 将该方法应用于实现刻蚀工艺三维表面仿真中, 模拟结果与实验结果对比验证了该方法的有效性. 关键词： 等离子体刻蚀 元胞自动机 表面演化方法 高分辨率仿真