两个具有耦合时滞的分数阶复杂网络的延迟投影同步与参数辨识

研究两个具有耦合时滞的分数阶复杂网络的延迟投影同步与参数辨识的问题.首先,建立具有耦合时滞以及模型参数不确定分数阶复杂网络模型,并给出驱动网络与响应网络的延迟投影同步误差模型;其次,设计有效的控制器以及参数自适应律以实现两个网络之间的延迟投影同步与参数辨识,给出了实现延迟投影同步与参数辨识的充分条件,对该充分条件给出了严格的数学证明,并通过一个数值仿真实例验证了所提出方法的有效性和可行性;然后,对3种特例进行讨论,并得到实现同步的充分条件,这3种情况分别为具有耦合时滞的延迟同步、具有耦合时滞的投影同步和没有耦合时滞的延迟投影同步;最后,对模型中耦合强度、时滞因素以及投影比例对同步的影响进行了讨论.     

一般耦合结构时变时滞复杂网络的同步准则

研究一般耦合结构时变时滞复杂网络的同步问题,取消了复杂网络外部耦合矩阵是对称且不可简约的约束.对于一般的外部耦合矩阵,考虑了具有复数特征根的情况,并对复数域上的向量进行相应的处理.基于Lyapunov稳定性理论,利用矩阵分解技巧及线性矩阵不等式方法,通过构造适当的Lyapunov泛函,得到了网络系统实现同步的充分条件.为验证所得结论的有效性,对网络同步问题进行了数值仿真.仿真结果显示本文的同步准则较已有研究具有更小的保守性.     

时滞耦合和非时滞耦合的奇异复杂动态网络之同步性准则

本文利用李雅普诺夫稳定性理论,对时滞耦合和非时滞耦合的奇异复杂动态网络之同步获得了一些新的充分条件.这些条件均可转化为求解一组线性矩阵不等式(LMI).在降低准则保守性的过程中,本文充分运用了矩阵函数的凸性和自由权重矩阵理论.最后给出了两个数例;与已有文献做了比较,说明本文结论的有效性,以及较低的保守性.     

具有切换拓扑的时滞耦合网络的同步控制

针对一类具有耦合时滞且耦合拓扑集合给定的动态复杂网络模型存在同步的要求,传统的网络同步不能通过单一拓扑结构实现时,如何通过拓扑之间的切换来实现网络的同步.为解决上述问题,提出构建合适的Lyapunov函数给出了网络同步所需要满足的条件和相应的切换规则.进行仿真的结果与已有的研究结果相比,动态复杂网络的耦合矩阵可为一般的形式,并不需要满足同时上三角化和同时对角化等条件.仿真结果验证了结论的有效性和正确性.     

具有混合时滞的四元数神经网络全局同步性控制

本文研究了具有混合时滞的四元数神经网络的全局同步性问题. 在不要求网络的激活函数可分离为两个复数或四个实数的情况下, 通过选取合适的 Lyapunov -Krasovskii 泛函, 并运用驱动-响应同步、自由权矩阵方法和矩阵不等式技巧, 给出了网络全局同步性的充要条件, 建立了同步控制器的设计方法. 给出的同步性判据是四元数和复数两种形式的线性矩阵不等式, 同时与已有的结果进行了对比. 最后通过一个数值仿真算例验证了所得结论的有效性.     

基于分散反馈控制的时滞混沌大系统

研究一类具有时滞关联的时滞大系统的混沌现象和分散反馈控制问题。应用线性矩阵不等式（LMI）方法,基于李雅普诺夫定理,分别得到了系统存在分散时滞反馈控制器和分散标准反馈控制器的充分条件,并利用分散时滞反馈控制器对系统中存在的不稳定周期轨道的追踪控制问题进行研究。仿真结果表明控制器具有很强的鲁棒性。     

一类线性时滞系统的鲁棒稳定性分析

针对一类具有范数有界不确定性和2个继发时变时滞的线性时滞不确定系统,研究了其时滞依赖鲁棒稳定性问题。通过定义充分利用时变时滞上下界信息的新型Lyapunov—Krasovskii泛函,并结合时滞系统相关处理方法和线性矩阵不等式方法,得到了时滞线性不确定系统鲁棒渐近稳定所满足的条件。为了降低结论的保守性,对某些项进行了较紧致的估计。此外,并未引入自由权矩阵。最后并通过2个数值仿真证实了方法的有效性和优越性。     

基于LM I 方法的时滞分布参数控制系统的镇定

针对常时滞、多个常时滞及多个变时滞的分布参数控制系统，提出一种与现有研究分布参数控制系统不同的方法．该方法通过构造平均Lyapunov函数，利用LMI和矩阵不等式知识，在只要求系统本身所固有的系数是负定矩阵的条件下，给出了所研究的分布参数系统镇定的充分条件．当模型中时滞为常时滞时，所得的充分条件与时滞无关；当模型中时滞为变时滞时，所得模型的镇定准则依赖于时滞．此外，该方法一个显著优点是所获得的条件容易检验，因而易于应用．     

线性定常时滞系统的鲁棒控制

在建立线性定常时滞系统模型的基础上,给出了时滞系统是独立鲁棒稳定的条件,并利用Lyapunov理论给予一些定理的证明,同时设计出了使闭环系统时滞独立鲁棒稳定的状态反馈控制器（即时滞独立鲁棒镇定问题）,最后给出的一个数值例子中用Matlab编程求出了符合条件的正定矩阵和控制律,从算例结果验证了所得出的结论。     

具有相似节点的耦合时滞复杂网络的稳定性与同步控制分析

讨论具有相似节点的耦合时滞复杂网络的稳定和同步问题,且网络模型的外部耦合满足耗散条件.对于不同维数节点的复杂网络,根据节点之间相似参量的信息,利用线性矩阵不等式方法设计出含有相似参量的分散控制器,给出耦合复杂网络实现稳定的时滞独立判定准则.定义了含有相似参量的同步流形的概念,并设计了相应的分散控制器,给出了能使整个复杂网络同步的时滞独立判定条件.数值算例表明了所提出设计方法的有效性.     

Strategic bidding in continuous double auctions

In this paper, we describe a novel bidding strategy that autonomous trading agents can use to participate in Continuous Double Auctions (CDAs). Our strategy is based on both short and long-term learning that allows such agents to adapt their bidding behaviour to be efficient in a wide variety of environments. For the short-term learning, the agent updates the aggressiveness of its bidding behaviour (more aggressive means it will trade off profit to improve its chance of transacting, less aggressive that it targets more profitable transactions and is willing to trade off its chance of transacting to achieve them) based on market information observed after any bid or ask appears in the market. The long-term learning then determines how this aggressiveness factor influences an agent's choice of which bids or asks to submit in the market, and is based on market information observed after every transaction (successfully matched bid and ask). The principal motivation for the short-term learning is to enable the agent to immediately respond to market fluctuations, while for the long-term learning it is to adapt to broader trends in the way in which the market demand and supply changes over time. We benchmark our strategy against the current state of the art (ZIP and GDX) and show that it outperforms these benchmarks in both static and dynamic environments. This is true both when the population is homogeneous (where the increase in efficiency is up to 5.2%) and heterogeneous (in which case there is a 0.85 probability of our strategy being adopted in a two-population evolutionary game theoretic analysis).     

双Quantales模中的张量积

在双Quantales模中引入了双Quantales模双同态的概念,在完备格张量积的基础上,得到了双Quantales模张量积的具体形式,讨论了双Quantales模张量积的一些重要性质。     

Fair Electronic Cash Based on Double Signatures

In order to decrease crimes such as money laundering,blackmailing etc.in electronic cash systems,fair electronic cash has been a major focus of academic research in electronic commence.When a bank finds some dubious cash or owner,the trusted entity or trustee can help him to revoke the anonymity of the cash.In the previous protocols,the trustee knows all the information of the cash whether he is trusted or not,that is,he can trace the user or cash unconditionally,Furthermore,the dishonest trustee may deceive a user,which means that the may withdraw cash while tracing other users,Such cases are unfair to the honest users.A new fair electronic cash protocol based on untrustworkthy trustees is proposed in this paper.The key idea is that the coin structure should include the signatures of both the trustee and the bank so that the trustee shares the information of the cash with the bank,while we do not use the secret sharing scheme.In contrast with the previous protocols.neither the trustee nor the bank can trace the money without the help of the other entity.In this way,the privacy of the user is protected furthest.Also,the trustee is off-line in the protocol,which means that he will not be involved in withdrawing the cash.Therefore,the protocol is efficient for implementation.     

基于间隔型双边拍卖的网格资源预留算法

针对已有基于竞价拍卖的网格资源预留方法存在的问题，提出了一种基于间隔型双边拍卖的网格资源预留算法。根据网格资源预留的需求和拍卖机制的特点，给出了网格系统模型；基于间隔型双边拍卖的思想，设计了适合网格系统的资源拍卖机制，给出了详细的网格资源预留算法；算法的最优性分析表明：在资源拍卖过程，提供真实信息对用户方和资源方均是唯一占优策略，且算法能够保证中标资源供需平衡。 最后，模拟实验结果证明了算法的有效性和正确性。     

Stability analysis of time-delay systems via free-matrix-based double integral inequality

Based on the free-weighting matrix and integral-inequality methods, a free-matrix-based double integral inequality is proposed in this paper, which includes the Wirtinger-based double integral inequality as a special case. By introducing some free matrices into the inequality, more freedom can be provided in bounding the quadratic double integral. The connection of the new integral inequality and Wirtinger-based double one is well described, which gives a sufficient condition for the application of the new inequality to be less conservative. Furthermore, to investigate the effectiveness of the proposed inequality, a new delay-dependent stability criterion is derived in terms of linear matrix inequalities. Numerical examples are given to demonstrate the advantages of the proposed method.     

基于双层扫描策略的IPv6蠕虫研究*

由于IPv6网络地址空间巨大,传统的基于随机扫描、顺序扫描等网络层扫描策略的IPv4蠕虫难以在IPv6网络中传播。构建了一种新型IPv6网络蠕虫——V6-Worm,该蠕虫运用双层扫描策略,在子网内和子网间分别采用基于组播和基于域间路由协议路由前缀的扫描策略,并在此基础上建立了一种双层蠕虫传播模型(double layer model,DLM)来仿真V6-Worm的传播趋势。仿真结果表明,V6-Worm可在大规模IPv6网络中传播,与采用随机扫描策略的CodeRed相比,V6-Worm具有更快的传播速度。     

一种基于蜜蜂双种群进化的遗传算法

提出了一种基于蜜蜂双种群进化的遗传算法(BDPGA)。算法共有两个种群,一个是通过迭代进行遗传操作得到的,一个是在每代进化过程中随机引入的。每个种群中的最优个体作为蜂王分别以概率与其它个体(雄蜂)进行交配操作。既能增强对种群最优个体所包含信息的开采能力,又能提高算法的勘探能力,从而避免算法过早地收敛。实验结果表明,该算法对于改进和提高遗传算法性能是有效可行的。     

基于双晶片压电传感器特性分析

用模态分析法分析双晶片压电力、振动、位移传感器的位移特性及灵敏度特性,并给出灵敏度与压电材料参数及晶片几何尺寸的关系。其仿真分析结果对压电双晶片用于力、振动、位移等传感器的设计具有重要意义。     

Online double auction mechanism for perishable goods

One-sided auctions are used for market clearing in the spot markets for perishable goods because production cost in spot markets is already “sunk.” Moreover, the promptness and simplicity of one-sided auctions are beneficial for trading in perishable goods. However, sellers cannot participate in the price-making process in these auctions. A standard double auction market collects bids from traders and matches the higher bids of buyers and lower bids of sellers to find the most efficient allocation, assuming that the value of unsold items remains unchanged. Nevertheless, in the market for perishable goods, sellers suffer a loss when they fail to sell their goods, because their salvage values are lost when the goods perish. To solve this problem, we investigate the suitable design of an online double auction for perishable goods, where bids arrive dynamically with their time limits. Our market mechanism aims at improving the profitability of traders by reducing trade failures in the face of uncertainty of incoming/departing bids. We develop a heuristic market mechanism with an allocation policy that prioritizes bids of traders based on their time-criticality, and evaluate its performance experimentally using multi-agent simulation. We find out that our market mechanism realizes efficient and fair allocations among traders with approximately truthful behavior in different market situations.     

双光栅干涉仪数字式位移传感器的研究

为了检定高准确度位移传感器、几何量计量定位、微细加工测量,同时,也测量那些可以转换为微位移或光程差的其它物理量。基于双光栅干涉仪原理,设计了一种数字式位移传感器,对该装置进行了理论分析和计算机模拟,实验验证:该测量装置的绝对误差不大于0.019μm。