基于时延嵌入式隐马尔科夫模型的癫痫脑电分类算法

癫痫脑电的分类识别能够为癫痫的预警和病程的发展监测提供强有力的技术支持。传统的癫痫脑电分类识别方法需要从较长的时间序列中提取特征,难以刻画大脑的瞬态变化,检测低效且耗时,降低了癫痫预警的有效性。针对上述问题,提出一种基于隐马尔科夫模型的癫痫脑电分类算法。该方法通过时延嵌入式隐马尔科夫模型(time-delay embedded hidden Markov model,TDE-HMM)对脑电进行状态估计,并提取状态序列中的状态切换特征,通过多层感知机(multiple layer perceptron,MLP)实现对不同癫痫发作阶段脑电的有效辨识。实验结果表明,相较于小波变换、微分熵等传统特征,所提方法准确率高,能够有效刻画癫痫不同阶段的大脑状态变化,为癫痫脑电的分类识别和状态分析提供了新的备选方案。     

血吸虫病蔓延周期的灰色预测模型

对血吸虫病蔓延高峰期的预测具有深远的意义。本文建立一种新的灰色预测模型,对该病蔓延发展的高峰期进行预测,通过实例计算分析,预测结果正确,模型拟合精度为优。     

SEA方法及其在C~3I系统效能分析中的应用(Ⅱ)——交战模型

本文采用ＳＥＡ方法建立了Ｃ３Ｉ系统在一种典型交战环境下的系统效能模型及其分析程序,举例说明了系统效能计算结果的战术涵义。由于Ｃ３Ｉ系统所处的交战环境是千变万化的,因此采用ＳＥＡ方法建立一般交战情形下通用的Ｃ３Ｉ系统效能模型仍是十分困难的工作。然而,本文的分析过程可起到一定的示范作用。     

基于神经网络和微分对策理论的制导律

根据微分对策制导律目前面临的困境,本文尝试将神经网络引入微分对策制导律。采用ＢＰ模型,将微分对策的定量和定性分析结合起来。以导弹与飞机格斗为例,探讨其实现的可能性和优点,为将来发展基于微分对策理论的智能制导律提供了一定的思路。     

有色噪声中多个周期相近信号参数的估计算法

本文提出了一种“谐波组清除算法”来估计周期信号的参数。该算法不仅计算简单并可获得较高的频率分辨率,而且对信号模型具有较强的鲁棒性。最后,用数值仿真数据与实测直升机噪声数据对该算法进行了检验。     

连续竞价市场中格式化特征形成机理的仿真研究

现有的研究一般将金融市场中的胖尾分布、波动聚集、长期记忆等格式化特征的形成机理归于交易者的行为.为了研究市场交易机制对这些特征有何影响,以我国证券市场交易制度为蓝本,建立了一个连续竞价市场的基于Agent的仿真模型.仿真结果表明:在连续竞价机制下,即使Agent是理性的基本分析者或简单的随机交易者,模型仍然能够再现上述特征.这一结果说明,交易机制也是导致格式化特征的重要原因.     

Novel cued search strategy based on information gain for phased array radar

A search strategy based on the maximal information gain principle is presented for the cued search of phased array radars. First, the method for the determination of the cued search region, arrangement of beam positions, and the calculation of the prior probability distribution of each beam position is discussed. And then, two search algorithms based on information gain are proposed using Shannon entropy and Kullback-Leibler entropy, respectively. With the proposed strategy, the information gain of each beam position is predicted before the radar detection, and the observation is made in the beam position with the maximal information gain. Compared with the conventional method of sequential search and confirm search, simulation results show that the proposed search strategy can distinctly improve the search performance and save radar time resources with the same given detection probability.     

Research on secure buyer-seller watermarking protocol

A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyer＇s watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.     

Cluster Synchronization in a Complex Dynamical Network with Two Nonidentical Clusters

This paper further investigates cluster synchronization in a complex dynamical network with two-cluster. Each cluster contains a number of identical dynamical systems, however, the subsystems composing the two clusters can be different, i.e., the individual dynamical system in one cluster can differ from that in the other cluster. Complete synchronization within each cluster is possible only if each node from one cluster receives the same input from nodes in other cluster. In this case, the stability condition of one-cluster synchronization is known to contain two terms： the first accounts for the contribution of the inner-cluster coupling structure while the second is simply an extra linear term, which can be deduced by the ＂same-input＂ condition. Applying the connection graph stability method, the authors obtain an upper bound of input strength for one cluster if the first account is known, by which the synchronizability of cluster can be scaled. For different clusters, there are different upper bound of input strength by virtue of different dynamics and the corresponding cluster structure. Moreover, two illustrative examples are presented and the numerical simulations coincide with the theoretical analysis.     

要加强对复杂适应性系统的研究——对自组织理论的反思

简单回顾了自组织理论的发展历史、内容和采用的方法,重点分析了自组织理论的研究对象和研究范围;指出自组织理论在研究复杂系统上的局限性——只适于研究简单巨系统,它研究的是系统演化的结果而非过程;自组织理论使用微分方程作为数学工具,要求子系统之间的相互作用要满足叠加原理而不考虑涌现的情况。在此基础上,本文提出要加强复杂适应性系统的研究,具体有两方面的工作：首先要加强计算机作为数学工具的应用,扩展对系统状态描述的范围;另外要加强对层次性的研究,重点是对涌现问题的分析。最后提出现在加强复杂系统的研究应从实际的具体系统入手。