反向累加生成的特性及GOM(1,1)模型的优化

针对反向累加序列的生成与建模问题, 分析了反向累加生成的准光滑性和准指数规律, 进而给出反向累加生成序列的灰建模条件. 证明了基于反向累加生成的齐次与非齐次离散指数函数之间的关系, 并经过理论推导得到了GOM(1,1)模型的最优背景值. 结果表明, 优化的背景值与GOM(1,1)模型的时间响应函数具有较好的一致性, 从而可以在理论上有效提高传统模型的精度. 最后通过实例验证了优化模型的实用性与有效性.     

Distribution of one-error linear complexity of binary sequences for arbitrary prime period

Complexity measures for sequences,such as the linear complexity and the k-error linear complexity,play an important role in stream ciphers.This contribution studies the distribution of 1-error linear complexity of binary sequences with arbitrary prime period.For any odd prime N,the authors present all possible values of 1-error linear complexity of N-periodic binary sequences,and derive the exact formulas to count the number of N-periodic binary sequences with any given 1-error linear complexity.     

Hybrid chaotic sequence for QS-CDMA system with RAKE receiver

A class of the hybrid chaotic sequences is presented. The generator of the sequences is given and realized by the digital method. The hybrid chaotic sequences exhibit good random properties that are very important for the performance of QS-CDMA system with RAKE receiver. The performance of the system is analyzed when the hybrid chaotic sequences are used as spreading codes in a QS-CDMA system with RAKE receiver and compared with those obtained for m-se-quences and logistic sequences. The results show that the hybrid chaotic sequences are a class of very promising spreading codes for QS-CDMA system.     

RSC卷级码中的自结尾序列和最小码重

对自结尾输入序列进行了研究 ,证明了自结尾输入序列的若干性质 ,揭示了自结尾输入序列与RSC码的最小码重关系。指出较短的自结尾输入序列通常产生较轻的输出码重。尤其对一类重量为 2的自结尾序列给予了特别关注 ,并进行了深入研究。最后给出了RSC码最小码重的一个上限 ,并通过例子说明这个上限是很紧的 ,很多情况下就是最小码重。     

基于k近邻平均距离的异步航迹关联算法

针对异步不等速率下局部节点航迹关联复杂问题, 提出了基于k近邻平均距离的异步航迹直接关联算法。首先, 给出不等长航迹序列间的k近邻平均距离计算规则, 进而计算得到不等长航迹序列间的灰色关联度, 再利用经典分配法进行航迹关联判定。算法无需时间同步, 避免估值误差传播积累。仿真数据表明, 算法正确关联率高、耗时较短、局部节点采样周期和开机时机不一致等异步因素对算法影响不明显, 并且算法不受噪声分布形式和目标数目变化的影响。     

建立系统科学基础理论框架的一种可能途径与若干具体思路(之八)——固定环境中的稳态涌现

该文是总标题下的第八篇。全文的总目的是试图从现代物理、分子生物学与脑神解剖学等学科领域的最新实验事实，以及相应的前沿理论领域围绕着演化概念研究的展开所获得已有与成就为基础，按照“由大爆炸理论所描述的物理世界之最初情景出现以来，世界物质总是在其不同时空点具体结构状态下的几种基本相互作用属性形成的机械造成的物质－能量结构与分布仍非完全平衡态热的推动下，不断的一层一层完成其全方位整体性进一步精细平衡结构，实现其该层次从无序到有序的起伏演化－这一总体自然法则”的认识主线，提出一种建立系统科学基础理论的定性定量框架思路与若干细节方法。文中对相互作用、进化、演化、适应性与复杂性等概念进行了分析，对突变、分歧、吸引子、混沌、协同、分形等基于此种理论做了一处较为直观的诠释。同时，也将论及信息的本质与其人本意义下的价值概念，特别是她与非线性的密切关系等。当然，这一切均还是初步的，尽管其中一部分我们也已经获得了一些较为严谨的结果。     

Upper and lower bounds on PMEPR in OFDM systems and application

Upper and lower bounds on peak-to-mean envelope power ratio (PMEPR) in OFDM systems are derived in this paper. The derivation results show that the upper bound on PMEPR only depends on the aperiodic autocorrelation functions of the data sequences and is quite useful for rapid elimination of sequences that have PMEPR exceeding a given threshold. According to the lower bound on PMEPR,it has a great change as N (number of subcarriers) varies only for a very small N. For a 16-subcarrier BPSK-OFDM system, a selective mapping (SLM) way to reduce PMEPR is investigated with the upper bound on PMEPR and the distribution of PMEPR for all possible message sequences is given. The analytic results show that the maximal PMEPR is about 6.5 dB which is 5.5 dB less than that in worst situation.     

Reduction effect of SLM on the PAPR in MC-CDMA system

1.INTRODUCTION Asanewmulticarriermultiple accesscommunication method,themulticarrierCDMA(MC CDMA)based onthecombinedschemeofCDMAandOFDM,has manyadvantages,includinghigherfrequencyeffi ciency,fittinghigh speeddatatransmissionandbet terabilityofcombatingmultipathfading.Itislikely tobecomethemultiple accessmethodusedinthe fourthgenerationmobilecommunicationsystem[1～4].However,sincetheMC CDMAsystemusesthe OFDMmodulationmethod,itinheritsinevitablythe problemonthehigherpeak averagep…     

混沌直扩序列的优选及与传统序列的性能比较

为了提高异步直扩序列码分多址 (DS/CDMA)系统的容量和保密性能 ,从整个扩频序列集合相关函数的均方值出发 ,对一类由一维混沌映射产生的混沌直扩序列与传统的伪随机序列如m序列、Gold序列和Kasami序列等 ,在异步DS/CDMA系统中作了性能比较研究。计算机仿真表明 ,其性能与传统序列相当 ,其序列数较m序列数多 ,适于作CDMA系统的扩频码 ,并由此提出了一种混沌直扩序列的优选方法。     

吉普问题的最优序列

介绍了吉普问题的由来及发展,在动态规划原理的基础上给出了处理吉普问题的有效工具——最优序列利用最优序列研究了Gale往返吉普问题及其变形.     

混沌扩频序列的优选算法及其系统性能研究

为了获得多址通信中优良的伪随机特性码组,提出了一种混沌序列的优选算法。通过对混沌系统迭代结果的截断和量化处理,根据扩频序列的理想特性和多址干扰指数,给出了优化混沌序列码组的具体步骤,并对传统的Gold序列和多种混沌序列的码组性能作了比较和分析。对DS/CDMA系统性能的仿真结果表明,优选混沌扩频序列的相关性能优于传统的伪随机扩频序列,有利于解决CDMA移动通信中的抗多址干扰及多用户检测等关键问题,从而使混沌扩频系统的抗干扰能力和抗破译能力得到增强。     

变形模板技术及其在多目标跟踪中的应用

变形模板技术是一种能够精确匹配、分割目标轮廓的图像处理技术。在过去20多年左右的时间里,该项技术已取得了长足的发展并显示出强大的生命力,如今变形模板模型已被广泛的应用于图像分析和计算机视觉等领域之中。从方法论的角度介绍了变形模板技术的理论基础、建模的一般过程及技术难点与解决方法,并以一种基于Snake模型的多目标跟踪算法为例介绍了该项技术在高空对地观测中对多个运动目标的精确分割与跟踪的应用。     

Constrained predictive control of nonlinear stochastic systems

The receding horizon control (RHC) problem is considered for nonlinear Markov jump systems which can be represented by Takagi-Sugeno fuzzy models subject to constraints both on control inputs and on observe outputs. In the given receding horizon, for each mode sequence of the T-S modeled nonlinear system with Markov jump parameter, the cost function is optimized by constraints on state trajectories, so that the optimization control input sequences are obtained in order to make the state into a terminal invariant set. Out of the receding horizon, the stability is guaranteed by searching a state feedback control law. Based on such stability analysis, a linear matrix inequality approach for designing receding horizon predictive controller for nonlinear systems subject to constraints both on the inputs and on the outputs is developed. The simulation shows the validity of this method.         

Petri网的分享合成操作

通过引入Fork算子，建立Petri网的一种新的合成操作一分享合成，分享合成探作与传统的共享合成操作相比更适合于描述信息系统的建模。在分享合成时，子网中任何与分享库所无关的变迁序列在合成后保持不变，分享合成对于子网内由分享库所引发的变迁序列也保持不变。分享合成实际上增加了分享库所引发变迁序列发生的机会，使得到达输出集的机会增加。最后介绍了Petri网分享合成操作在信息系统安全管理中的应用。     

基于面向对象的视频系统建模研究

针对移动信道的长突发误码特性,提出采用组合随机数发生器法来产生(0,1)均匀分布随机数,由它产生信道差错序列,并建立一个具有一定精度的一阶三状态Markov仿真信道模型,在此基础上应用面向对象技术构建了一个无线视频传输系统模型。通过仿真实验表明模型构建具有高度的可扩展性,系统仿真具有较高的精度,且能较好的反映移动信道的特性。     

OFDM-CDMA系统建模仿真及误码率分析

OFDM－CDMA是将OFDM与CDMA相结合的综合技术，是继第三代移动通信之后移动通信技术中的新热点。本文阐述了其基本原理，建立了其中一种性能较好的结合方案，即MC－CDMA系统的仿真模型。在该系统模型下，做了用三种不同的扩频序列m序列、Gold序列、Kasami小集合序列进行扩频调制下的系统仿真性能分析，分别给出误码率曲线并进行对比，得出了较理想的结论。     

灰色关联度模型正负性问题的研究及其改进

灰色关联分析是通过对序列几何关系的度量来比较系统中多因素关系的紧密程度,其紧密程度可由序列曲线几何形状的接近(或相近)程度来度量。因此可以利用参考序列和比较序列各对应时段斜率的比值来反映序列之间的紧密程度。首先定义了广义变异系数,并提出一种新的关联度计算方法,该关联度能够反映序列的正相关与负相关关系,并且只与序列的形状有关,而与它们在空间的相对位置无关。此方法充分利用了序列各时点的信息及正、负相关性。最后通过算例验证了它的合理性与实用性。     

Hilbert Problem 15 and Ritt-Wu Method (II)

This paper proves three statements of Schubert about cuspal cubic curves in a plane by using the concept of generic point of Van der Waerden and Weil and Ritt-Wu methods. They are relations of some special lines: 1) For a given point, all the curves containing this point are considered. For any such curve, there are five lines. Two of them are the tangent lines of the curve passing through the given point. The other three are the lines connecting the given point with the cusp, the inflexion point and the intersection point of the tangent line at the cusp and the inflexion line. 2) For a given point, the curves whose tangent line at the cusp passes through this point are considered. For any such curve, there are four lines. Three of them are the tangent lines passing through this point and the other is the line connect the given point and the inflexion point. 3) For a given point, the curves whose cusp, inflexion point and the given point are collinear are considered. For any such curve, there are five lines. Three of them are tangent lines passing through the given point. The other two are the lines connecting the given point with the cusp and the intersection point of the tangent line at the cusp and the inflexion line.

     

IDENTIFICATION ERROR BOUNDS AND ASYMPTOTIC DISTRIBUTIONS FOR SYSTEMS WITH STRUCTURAL UNCERTAINTIES

This work is concerned with identification of systems that are subject to not only measure-ment noises.but also structural uncertainties such as unmodeled dynamics,sensor nonlinear mismatch,and observation bias.Identification errors are analyzed for their dependence on these structural uncer-tainties.Asymptotic distributions of scaled sequences of estimation errors are derived.     

等待时间受限的流水车间调度问题的若干性质

等待时间受限的流水车间调度问题广泛存在于高温连续作业或中间产品不稳定的流水车间生产管理过程中, 要求工件在相邻机器上的等待时间不能超过一定的上限. 针对以最小化最大完工时间为目标函数的该类问题, 研究了加工机器上的工件序列特征, 并在此基础上分析了基于排列排序进行问题求解的可行性和有效性, 为算法求解提供了理论依据.