基于FKCM的球磨机系统T-S模糊建模方法

针对传统的描述热工过程动态数学模型的方法难以建立非线性模型的缺点,提出了一种基于模糊核聚类的球磨机系统T-S模糊建模算法.该算法首先通过灰色关系法确定模型输入变量,利用FKCM聚类算法对输入空间进行模糊划分,确定T-S模型的前件结构和前件参数;进而利用最小二乘算法确定模糊规则的后件参数.最后,利用数字仿真数据对球磨机系统进行模糊建模,建模结果表明该算法简单、实用,模型能够精确地描述过程的非线性.     

一种基于小波的电网谐波检测新方法

在电力系统中存在许多非线性负载,由此产生的谐波对电网的电能质量造成很大的影响.为了保证电网的电能质量,必须监测由此产生的谐波.首先讲解用于谐波检测的小波变换的理论,其次在MATLAB中用FFT、小波分解和小波包变换三种方法对由电焊机产生的谐波电流进行了仿真分析与计算.仿真结果表明:小波分解能够有效地分离基波,小波包变换能够分离任意次谐波.该方法具有普遍适用性,与使用昂贵的专用测量仪器相比,不失为一种好的替代方法.     

A differential game model for a developing and a developed country

A differential game (DG) model for a developing and a developed country is considered. Each player makes decisions about how much resource to be used to restrict the opponent's development so as to maximize his weighted sum of current consumption and final output. Current consumption is assumed to be preferred to final output for both players. The developing country is assumed to have a higher economic growth rate and a higher preference to final output, whereas the developed country is assumed to have a higher initial income and a higher efficiency in restricting his opponent. This problem is investigated under three kinds of information structures, i.e., a zerosum, a nonzero-sum, and a Stackelberg game. Open-loop equilibrium solutions are obtained for all the three cases. Economic implications of the result are provided. The research is supported by the National Natural Science Foundation of China under Grant Nos. 70771118 and 70371030 and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry under Grant No. 2006.331.     

Model and algorithm of flow interception problem with multi-type of flows

To study simultaneous location of different kinds of facilities, a new model of flow interception problem with multi-type of flows is proposed, with the consideration of multi-purpose flows and the influence of facilities on each other. To be more practical, the objective is to maximize the benefits from flow-by customers instead of maximizing flows in the past. Since this problem is NP-hard and there is no optimal solution for large network, greedy and improved greedy heuristic algorithms are proposed. A computational example is presented to show that the optimal location decisions are proved to be strongly dependent on the influence coefficients and average profits by one customer and different types of facilities are almost co-located. Finally the results of sensitivity analysis are reported.     

基于差价补偿策略的集装箱班轮运输定价模型

针对集装箱班轮运输定价问题,构建差价补偿策略下班轮运输的定价模型,研究差价补偿策略下托运人订舱行为和承运人定价决策,分析市场需求波动与承运人定价、差价补偿系数、承运人收益的内在关系,以及承运人定价对托运人订舱量的影响,并通过数值分析进行验证.结果表明:随着市场需求波动的增大,承运人最优定价与最大收益降低,而差价补偿系数增大;且托运人订舱量随着承运人定价的增大而减少.承运人采用差价补偿策略时,市场需求波动存在一个上限值,如果需求波动小于该值,则承运人采用差价补偿策略有利于其提高收益.     

Underdetermined DOA estimation and blind separation of non-disjoint sources in time-frequency domain based on sparse representation method

This paper deals with the blind separation of nonstation-ary sources and direction-of-arrival （DOA） estimation in the under-determined case, when there are more sources than sensors. We assume the sources to be time-frequency （TF） disjoint to a certain extent. In particular, the number of sources presented at any TF neighborhood is strictly less than that of sensors. We can identify the real number of active sources and achieve separation in any TF neighborhood by the sparse representation method. Compared with the subspace-based algorithm under the same sparseness assumption, which suffers from the extra noise effect since it can-not estimate the true number of active sources, the proposed algorithm can estimate the number of active sources and their cor-responding TF values in any TF neighborhood simultaneously. An-other contribution of this paper is a new estimation procedure for the DOA of sources in the underdetermined case, which combines the TF sparseness of sources and the clustering technique. Sim-ulation results demonstrate the validity and high performance of the proposed algorithm in both blind source separation （BSS） and DOA estimation.     

基于QHSME的装备危险耦合传导GERT分析

针对装备活动中危险耦合传导关系描述不清楚、分析不具体的问题,构建考虑任意分布的危险耦合传导图形评审技术（graph evaluation and review technique,GERT）改进模型。提出了系统危险度、危险耦元重要度、危险路径隶属度等扩展分析参数,进一步刻画装备活动中的微观危险信息;采用系统耦合理论和极大熵方法（maximum entropy,ME）配置GERT模型变量,并设计量子和声算法（quantum harmony search algorithm,QHS）求解危险度概率密度极大熵模型。最后,以飞机大表速低空俯冲科目为例进行分析。结果表明,与传统GERT模型比较,该改进模型能充分反映危险耦元对装备活动随机过程的交互影响关系,以及其他相关微观信息,且具有较好的求解精度与适用性。     

一种基于网络分析的语义冗余发现方法

以农业AGROVOC本体为例,结合语义万维网推理机制定性分析冗余信息产生原因,利用复杂网络分析方法量化推理过程中产生的冗余,进而确定本体中的核心概念,解决推理冗余问题。实验表明,复杂网络分析方法可从定量角度找出核心节点及导致推理产生冗余的边,并揭示了语义冗余引起的推理效率降低问题。为优化本体设计、提高推理效率提供了一种新的可行方法。     

Robust output regulation problem for discrete-time linear systems with both input and communication delays

Recently, the robust output regulation problem for continuous-time linear systems with both input and communication time-delays was studied. This paper will further present the results on the robust output regulation problem for discrete-time linear systems with input and communication delays. The motivation of this paper comes from two aspects. First, it is known that the solvability of the output regulation problem for linear systems is dictated by two matrix equations. While, for delay-free systems, these two matrix equations are same for both continuous-time systems and discrete-time systems, they are different for continuous-time time-delay systems and discrete-time time-delay systems. Second, the stabilization methods for continuous-time timedelay systems and discrete-time time-delay systems are also somehow different. Thus, an independent treatment of the robust output regulation problem for discrete-time time-delay systems will be useful and necessary.     

EMD新算法及其应用

经验模态分解（ENID）算法是Hilbert-Huang变换（HHT）的核心算法，它的分解效果依赖于包络线的生成算法和端点延拓算法。采用分段幂函数插值算法求包络成。结合一种改进的端点延拓算法。得到了一种新的EMD算法。分析了分段幂函数插值算法的收敛精度。从数学角度解释了选取该插值算法的原因．最后，结合一个股票模型的仿真结果说明新的EMD算法效果更好。