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1.
In this paper extensions to the numerical solution method of deterministic and stochastic Petri nets (DSPNs) are introduced in order to cope with deterministic transitions with marking-dependent firing delays. The basic idea lies in scaling each row of the generator matrix of the Markov chain subordinated to a deterministic transition with marking-dependent firing delay by the delay value corresponding to this marking. Computational formulas of this solution method are implemented in the software package DSPNexpress which completely automates the solution process of DSPNs. The extended modeling power of DSPNs is illustrated by a single-server queuing system with Poisson arrivals, degradable deterministic service requirements, and finite capacity. Christoph Lindemann was supported by the Federal Ministry for Research and Technology of Germany (BMFT) and by the German Research Council (DFG) under grants ITR9003 and Ho 1257/2-1, respectively. Reinhard German was supported by Siemens Corporate Research and Development and by a doctoral fellowship from the German Research Council (DFG) under grant Ho 1257/1-2.  相似文献   

2.
针对存在传输滞后的线性离散系统的状态反馈镇定问题,给出了系统可镇定的一个内部限制条件.为克服这一限制条件,提出了两种方法:一种是充分利用滞后状态的信息,另一种是设计带有递推动态的状态反馈控制器.研究结果表明,若系统在没有传输滞后时能通过状态反馈被镇定,则存在传输滞后时一定也能通过设计新的控制器使系统被镇定.  相似文献   

3.
变增益智能PID控制器设计   总被引:4,自引:1,他引:4  
针对典型的具有滞后的一阶惯性环节进行了变增益智能PID控制器的设计和数字仿真研究。仿真结果表明,该控制器对滞后较大的对象比常规最优PID控制器具有更好的控制性能。  相似文献   

4.
This paper investigates the consensus problem of second‐order Markovian jump multi‐agent systems with delays. Both network‐induced random delay and node‐induced state delay are considered, where the network‐induced random delay, subjected to a Markov chain, exists in the switching signal and the node‐induced state delay, related to switching topologies, is heterogeneous between any two linked agents. In order to reduce communication and control energy, an impulsive protocol is proposed, where each agent only can get delayed relative positions to neighbors and the velocity of itself at impulsive instants. By performing three steps of model transformation and introducing a mapping for two independent Markov chains, the consensus problem of the original continuous‐time system is equivalent to the stability problem of a discrete‐time expand error system with two Markovian jumping parameters and a necessary and sufficient criterion is derived. A numerical example is given to illustrate the effectiveness of the theoretical result.@@@@This work is supported by the National Natural Science Foundation of China under Grants 61374171, 61572210, and 51537003, the Fundamental Research Funds for the Central Universities (2015TS030), and the Program for Changjiang Scholars and Innovative Research Team in University (IRT1245).  相似文献   

5.
In irregular scientific computational problems one is periodically forced to choosea delay point where some overhead cost is suffered to ensure correctness, or to improve subsequent performance. Examples of delay points are problem remappings, and global synchronizations. One sometimes has considerable latitude in choosing the placement and frequency of delay points; we consider the problem of scheduling delay points so as to minimize the overal execution time. We illustrate the problem with two examples, a regridding method which changes the problem discretization during the course of the computation, and a method for solving sparse triangular systems of linear equations. We show that one can optimally choose delay points in polynomial time using dynamic programming. However, the cost models underlying this approach are often unknown. We consequently examine a scheduling heuristic based on maximizing performance locally, and empirically show it to be nearly optimal on both problems. We explain this phenomenon analytically by identifying underlying assumptions which imply that overall performance is maximized asymptotically if local performance is maximized.This research was supported in part by the National Aeronautics and Space Administration under NASA contract NAS1-18107 while the author consulted at ICASE, Mail Stop 132C, NASA Langley Research Center, Hampton, Virginia 23665.Supported in part by NASA contract NAS1-18107, the Office of Naval Research under Contract No. N00014-86-K-0654, and NSF Grant DCR 8106181.  相似文献   

6.
基于实时应用的网络传输时延测量设计   总被引:3,自引:0,他引:3  
本文对基于实时应用的计算机网络数据传输时延问题进行了深入研究,完成了对计算机网络时延的实际测试,针对实时应用和系统的复杂性特点,采用实际测试获得的数据,对网络传输时延进行了分析和评价,在技术上用软件方式实现时延测试,并基于ICMP协议反射式工作,增加了系统的灵活性和适应性,为网络设备提供了重要的评定依据。  相似文献   

7.
In this study, an appropriate inventory model for non-instantaneous deteriorating items with permissible delay in payments is considered. The purpose of this study is to find an optimal replenishment policy for minimizing the total relevant inventory cost. This mathematical model is a general framework that comprises numerous previous models such as in Ghare and Schrader [Ghare, P. M., & Schrader, G. H. (1963). A model for exponentially decaying inventory system. International Journal of Production Research, 21, 449–460], Goyal [Goyal, S. K. (1985). Economic order quantity under conditions of permissible delay in payments. Journal of the Operational Research Society, 36, 335–338], and Teng [Teng, J. T. (2002). On the economic order quantity under conditions of permissible delay in payments. Journal of the Operational Research Society, 53, 915–918] as special cases. We have developed some useful theorems to characterize the optimal solutions and provide an easy-to-use method to find the optimal replenishment cycle time and order quantity under various circumstances. Several numerical examples are given to test and verify the theoretical results. Finally, a sensitivity analysis of the optimal solution with respect to major parameters is also included. According to the results of numerical analysis, we provided several ways for the retailer to effectively reduce total annual relevant inventory cost.  相似文献   

8.
章治  曾夏玲 《计算机仿真》2012,29(5):130-132,238
研究网络控制系统的优化问题,提高系统的实时性。针对传统的网络控制系统是闭环系统,网络带宽有限,网络传输中的时间延迟、数据包丢失等问题不可避免。当发生以上情况时,反馈信号不能及时传回,造成控制信号发出延迟,影响了系统的实时性。为了解决上述问题,提出了一种非规律时滞补偿算法,把时滞信号引入自由权矩阵,能够得到延迟信号相关稳定性条件,并充分运用线性信号特征矩阵保证网络控制系统的性能,保证系统在线控制的实时性。证明改进方法能够避免控制信号延迟造成的滞后问题,提高了网络控制系统的实时性。  相似文献   

9.
研究了BACnet总线通信,针对MS/TP网络中的节点和报文传输性能进行了分析。运用有限状态机理论,在仿真环境下建立了混合型MS/TP网络的随机通信模型。针对应用层服务如读属性报文的传输等进行了仿真运行,评估了MS/TP网络传输的平均服务延迟特性,给出了楼宇控制器网络通信中的网络数据帧数、传输速率、延迟三者之间的关系。研究表明,当报文产生时间平均间隔一定,随着最大数据帧数增加,总线利用率变大,网络平均延迟变大。运用该方法可针对实际的网络结构和节点数量,评估出该网络的数据传输最大平均延迟和最大数据帧数,为总线网络的设计及优化提供了依据。  相似文献   

10.
We consider the Channel Multiple-Access problem for messages with strict delay constraints. The constraints are represented by an upper bound on the transmission delays. For this problem, and for binary collision-noncollision feedback per slot, we present a simple full sensing window Random-Access algorithm. We analyze the algorithm and we compute the fraction of maintained traffic and the expected delay for the successfully transmitted packet, for various input Poisson intensities and various values of the bound on the transmission delays.This work was supported by the U.S. Office of Naval Research, under Contract ONR-N14-86-K-0742.  相似文献   

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