含理想控制策略和期望轨道的最优控制

研究合理想控制策略和期望轨道的二次型最优控制问题．通过把控制问题转化为估计问题，从信息融合估计的角度，使原问题转化为求控制量的“最优估计”问题．通过实际算例表明。该算法所得二次性能指标值优于现有算法．     

基于综合预测算法的无线传感器网络移动节点定位策略

结合测距定位方法和移动节点历史定位信息,提出历史定位算法。在此基础上,引入移动节点相对运动角度测量,提出了基于综合预测算法的无线传感器网络移动节点定位策略。首先,根据测距结果选择较近的三个信标节点,并且加入移动节点的前一时刻坐标,应用最小二乘法,得到当前时刻的坐标;另一方面,由移动节点相对运动角度同样可以计算节点当前时刻的坐标;最后,将两种方法得到的坐标求平均值,作为综合预测算法给出的节点当前定位位置。仿真结果表明,所提出的定位策略能够高性能的实现移动节点定位,并且成本较低。     

Multicut问题参数算法的改进

Multicut问题即在一个图上删除最少个数的顶点,使得预先给定的一组顶点对均不连通.该问题是NP难的.在深入分析问题结构特点的基础上,运用集合划分策略和相关问题的最新研究结果,对它提出了一种时间复杂度为O*的参数化算法,其中,l为给定的顶点对数目,k为需删除的顶点个数.该算法明显改进了当前时间复杂度为O*的最好算法.     

Multicut问题参数算法的改进

Multicut问题即在一个图上删除最少个数的顶点,使得预先给定的一组顶点对均不连通.该问题是NP难的.在深入分析问题结构特点的基础上,运用集合划分策略和相关问题的最新研究结果,对它提出了一种时间复杂度为O*的参数化算法,其中,l为给定的顶点对数目,k为需删除的顶点个数.该算法明显改进了当前时间复杂度为O*的最好算法.     

Efficient Algorithm for the Constrained Two-dimensional Cutting Stock Problem

This paper considers the constrained two-dimensional cutting stock problem. Some properties of the problem are derived leading to the development of a new algorithm, which uses a very efficient branching strategy for the solution of this problem. This strategy enables the early rejection of partial solutions that cannot lead to optimality. Computational results are given and compared with those produced by a leading alternative method. These results show that the new algorithm is far superior in terms of the computer time needed to solve such problems.     

考虑非确定加工时间的柔性作业车间调度问题研究

加工时间不确定的柔性作业车间调度问题已逐渐成为生产调度研究的热点。采用区间表示加工时间范围,利用时间Petri网建立区间柔性作业车间调度问题形式化模型,并运用网模型的状态类图进行可达性分析,计算出所有可行变迁触发序列。通过对触发序列的时序分析,提出一种有效的逆向分步法来构造触发序列的时间约束不等式,进而求解线性规划问题来获得最小完工时间下界(上界)的优化调度策略。最后利用实例分析验证了模型及所提方法的正确性和可行性,为实际的区间柔性作业车间调度问题提供有效方案。     

Quality Control for Scalable Media Processing Applications

Many media processing applications create a load that varies significantly over time. Hence, if such an application is assigned a lower processing-time budget than needed in its worst-case load situation, deadline misses are likely to occur. This problem can be dealt with by designing media processing applications in a scalable fashion. A scalable media processing application can run in multiple qualities, leading to correspondingly different resource demands. The problem we consider is to find an accompanying quality control strategy, which minimizes both the number of deadline misses and the number of quality changes, while maximizing the quality of processing. We present an initial approach to the above problem by modeling it as a Markov decision process (MDP). Our model is based on measuring relative progress at milestones. Solving the MDP results in a quality control strategy that can be applied during runtime with only little overhead. We evaluate our approach by means of a practical example, which concerns a scalable MPEG-2 decoder.     

面向搜索时间受限的完全信息博弈UCT算法改进研究

针对完全信息博弈中搜索时间受限的算法设计问题,在考虑博弈模型不同特点及对结局影响程度的基础上,提出了分阶段的算法模型,给出了三阶段博弈算法设计方法。通过改造影响搜索策略的目标函数,使得在时间受限的前提下,能够方便控制每一阶段均更有效地搜索出较好策略,并给出相应的算法实现与分析。以点格棋为对象,给出了通过改造UCT算法中UCB公式的实现思路,设计了方向引导控制策略、多种算法混合、二进制压缩和并行化处理等技巧,有效提升了算法的效率和稳定性,并通过试验验证了所给出方法的有效性和效率。     

Primary exploration of nonlinear information fusion control theory

By introducing information fusion techniques into a control field, a new theory of information fusion control (IFC) is proposed. Based on the theory of information fusion estimation, optimal control of nonlinear discrete control system is investigated. All information on control strategy, including ideal control strategy, expected object trajectory and dynamics of system, are regarded as measuring information of control strategy. Therefore, the problem of optimal control is transferred into the one of information fusion estimation. Firstly, the nonlinear information fusion estimation theorems are described. Secondly, an algorithm of nonlinear IFC theory is detailedly deduced. Finally, the simulation results of manipulator shift control are given, which show the feasibility and effectiveness of the presented algorithm.     

Score calculation from final tournament tables

In this paper, we deal with the issue of determining the scores of all matches involved in a football tournament. The final table of the tournament, which shows the standings of the teams, is taken as the initial data of the problem. This is a different kind of combinatorial problems which require the construction of valid initial states according to some given final state. We use a rules-based method to solve the problem, analyzing the search space and introducing the notion of black&white graphs. The table data is firstly used to compute possible results of all played matches. Based on the results as well as the total number of scored and conceded goals, possible scores of the matches are then computed. The solution strategy is experimented on several final tables from previous World Cup tournaments. Other experiments are conducted for various team standings, measuring the time required to process some specific data of up to 10 teams.     

Event-triggered finite-time consensus of multiple Euler Lagrange systems under Markovian switching topologies

Finite-time consensus problem for multiple Euler Lagrange systems under Markovian switching topologies is investigated through an event-triggered control protocol. First, instead of the general stochastic topology, the graph of the entire system is governed by some Markov chains to the edge set, which can recover the traditional Markovian switching topologies in line with the practical communication environment. Then, by utilising an integral sliding-mode control strategy, rigorous analysis of finite-time consensus is performed through the graph theory and Lyapunov stability theory. An event-triggered communication law is delicately carried out for each agent, and Zeno behaviour of triggering time sequences is excluded absolutely. Finally, several simulation results on six two-link manipulators are given to verify the effectiveness of the designed control strategy.     

Relay pursuit of a maneuvering target using dynamic Voronoi diagrams

This paper addresses the problem of the pursuit of a maneuvering target by a group of pursuers distributed in the plane. This pursuit problem is solved by associating it with a Voronoi-like partitioning problem that characterizes the set of initial positions from which the target can be intercepted by a given pursuer faster than any other pursuer from the same group. In the formulation of this partitioning problem, the target does not necessarily travel along prescribed trajectories, as it is typically assumed in the literature, but, instead, it can apply an “evading” strategy in an effort to delay or, if possible, escape capture. We characterize an approximate solution to this problem by associating it with a standard Voronoi partitioning problem. Subsequently, we propose a relay pursuit strategy, that is, a special group pursuit scheme such that, at each instant of time, only one pursuer is assigned the task of capturing the maneuvering target. During the course of the relay pursuit, the pursuer–target assignment changes dynamically with time based on the (time varying) proximity relations between the pursuers and the target. This proximity information is encoded in the solution of the Voronoi-like partitioning problem. Simulation results are presented to highlight the theoretical developments.     

线性时变二次微分对策Nash策略的小波分析法(Ⅱ)——小波逼近解的收敛性

研究小波逼近分析方法的收敛性问题, 对线性时变二次微分对策Nash策略情形, 证明了Nash策略的小波逼近解收敛于精确解, 基于小波逼近的多尺度多分辨特性, 给出了误差估计的阶数.     

基于McCabe的软件复杂性度量与控制策略

软件复杂性度量与控制是软件开发面临的主要问题。本文通过对软件复杂性的定量分析,提出了软件复杂性的控制策略,该策略对开发高质量、高可靠性与高可维护性软件有一定的指导作用。     

基于McCabe的软件复杂性度量与控制策略

软件复杂性度量与控制是软件开发面临的主要问题。本文通过对软件复杂性的定量分析，提出了软件复杂性的控制策略，该策略对开发高质量、高可靠性与高可雏护性软件有一定的指导作用。     

基于加权平均值的一种分支启发式方法

在可满足性(Satisfiability,SAT)问题算法中提出有效的分支策略可以提高求解器的效率,文中主要从冲突分析的角度出发,依据变量是否发生冲突和冲突的次数,提出 一种基于加权平均值的分支启发式方法。该方法首先采用一组序列来记录变量是否参与冲突;其次赋予一个加权平均函数,依据变量的序列和决策层求出函数值;最后选择具有最大的函数值变量赋值,执行实例分析比较。由于该方法是对控制编码方法的改进,因此在进行例子分析时,采用了比较法和分析法,同时分析比较了所提方法、 SUM(Sum in experiment)策略和 ACIDS(Average Conflict-index Decision Score)策略。对SATLIB(SAT Little Information Bank)中的实例进行分析,结果表明所提方法能够实现更多子句被满足或最新冲突子句优先满足。     

SALSA: QoS-aware load balancing for autonomous service brokering

The evolution towards “Software as a Service”, facilitated by various web service technologies, has led to applications composed of a number of service building blocks. These applications are dynamically composed by web service brokers, but rely critically on proper functioning of each of the composing subparts which is not entirely under control of the applications themselves. The problem at hand for the provider of the service is to guarantee non-functional requirements such as service access and performance to each customer. To this end, the service provider typically divides the load of incoming service requests across the available server infrastructure. In this paper we describe an adaptive load balancing strategy called SALSA (Simulated Annealing Load Spreading Algorithm), which is able to guarantee for different customer priorities, such as default and premium customers, that the services are handled in a given time and this without the need to adapt the servers executing the service logic themselves. It will be shown that by using SALSA, web service brokers are able to autonomously meet SLAs, without a priori over-dimensioning resources. This will be done by taking into account a real time view of the requests by measuring the Poisson arrival rates at that moment and selectively drop some requests from default customers. This way the web servers’ load is reduced in order to guarantee the service time for premium customers and provide best effort to default customers. We compared the results of SALSA with weighted round-robin (WRR), nowadays the most used load balancing strategy, and it was shown that the SALSA algorithm requires slightly more processing than WRR but is able to offer guarantees - contrary to WRR - by dynamically adapting its load balancing strategy.     

基于LMI的参数随机变化系统的概率密度函数控制

针对模型参数在有界区域内随机变化的系统, 基于平方根 B 样条模型, 提出了输出概率密度函数 (Probability density function, PDF) 跟踪控制策略. 目标是控制系统输出的概率密度函数跟踪给定的概率密度函数. 通过 B 样条逼近建立了输出 PDF 和权值之间的对应关系, 把 PDF 的跟踪转化为权值的跟踪, 同时系统转化为 MIMO 系统,从而权值向量的跟踪就转化为 MIMO 系统的跟踪问题, 接着给出了系统输出概率密度函数跟踪给定概率密度函数的控制器存在的充分条件, 通过求解线性矩阵不等式完成状态反馈和输出反馈跟踪控制器的设计, 得到了系统具有 Hinfinity 范数界 Gamma 鲁棒镇定的结果. 仿真结果表明本文提出的控制算法是有效的.     

Cooperative attack strategy design via H−/H∞ scheme for linear cyber‐physical systems

This paper studies the problem of cooperative attack strategy design for cyber‐physical systems modeled by discrete‐time linear systems. A function that reflects the attacker's target is established, and a linear attack strategy is designed based on the objective function, in which the attack signal is unknown but energy bounded, while the statistical information of the existing ones is required to be known. Unlike the existing analysis methods for attack strategy, new Lyapunov functions that depend on the system states at different instants are constructed in the attack strategy analysis, and the sensitivity to the state estimator and the robustness against the detector are both enhanced on attack signals through using the H_?/H_∞ scheme. Finally, two simulation examples are given to show that the designed attack strategy achieves larger estimation errors and smaller detection probability simultaneously than the existing design methods.     

双足足球机器人守门策略研究

首先提出了双足足球机器人的体系结构,然后给出了基本步态算法,针对FIRA类人型项目比赛规则,提出了全新的双足足球机器人守门策略,最后给出了分析测距试验数据,验证了测距准确性和守门策略的合理性.