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1.
This paper considers a two-level supply chain consisting of one warehouse and one retailer. In this model we determine the optimal ordering policy according to inventory and transportation costs. We assume that the demand rate by the retailer is known. Shortages are allowed neither at the retailer nor at the warehouse. We study this model in two cases; decentralized and centralized. In the decentralized case the retailer and the warehouse independently minimize their own costs; while in the centralized case the warehouse and the retailer are considered as a whole firm. We propose an algorithm to find economic order quantifies for both the retailer and the warehouse which minimize the total system cost in the centralized case. The total system cost contains the holding and ordering costs at the retailer and the warehouse as well as the transportation cost from the warehouse to the retailer. The application of this model into the pharmaceutical downstream supply chain of a public hospital allows obtaining significant savings. By numerical examples, the costs are computed in MATLAB to compare the costs in the centralized case with decentralized one and to propose a saving-sharing mechanism through quantity discount.  相似文献   

2.
Inconsistency of multi-perspective requirements specifications is a pervasive issue during the requirements process. However, managing inconsistency is not just a pure technical problem. It is always associated with a process of interactions and competitions among corresponding stakeholders. The main contribution of this paper is to present a negotiations approach to handling inconsistencies in multi-perspective software requirements. In particular, the priority of requirements relative to each perspective plays an important role in proceeding negotiation over resolving inconsistencies among different stakeholders. An algorithm of generating negotiation proposals and an approach to evaluating proposals are also presented in this paper, respectively.  相似文献   

3.
The conventional data warehouse can only analyze historical data. This paper proposes a concept of agent-based real-time data warehouse in BI system, With this model we can improve the real-time performance of data warehouse. On the other hand, the BI system flexibility is enhanced in this model, which makes it much more efficient to manage the distributed environment.  相似文献   

4.
One important model in handling the multivariate data is the varying-coemcient partially linear regression model.In this paper,the generalized likelihood ratio test is developed to test whether its coefficient functions are varying or not.It is showed that the normalized proposed test follows asymptoticallyχ~2-distribution and the Wilks phenomenon under the null hypothesis,and its asymptotic power achieves the optimal rate of the convergence for the nonparametric hypotheses testing.Some simulation studies illustrate that the test works well.  相似文献   

5.
Supply-driven chain’s production is different from traditional demand-driven production because its supplies must guide the full production flow toward the markets and respond actively to customer demand. According to the control theory, a novel multi-variable operation model of supply-driven chain is discussed here, integrating suppliers, manufacturers, distributors and market demands. Especially the coordination problem between suppliers and manufacturers is discussed where suppliers play more important role than manufacturers. Because defect is common in real production system, the production operation of supply-driven chain with imperfect quality is described on the basis of fuzzy set to model the ambiguity of quality and to provide appropriate supply coordination mechanism. In a designed numerical example, it is apparent that both response and robustness performances of supply-driven production system on demand with imperfect quality are improved by a fuzzy proportional-integral- differential regulator. The proposed model may apply to similar productions with imperfect quality.  相似文献   

6.
Abstract Accurate forecast of future container throughput of a port is very important for its con struction, upgrading, and operation management. This study proposes a transfer forecasting model guided by discrete particle swarm optimization algorithm (TF-DPSO). It firstly transfers some related time series in source domain to assist in modeling the target time series by transfer learning technique, and then constructs the forecasting model by a pattern matching method called analog complexing. Finally, the discrete particle swarm optimization algorithm is introduced to find the optimal match between the two important parameters in TF-DPSO. The container throughput time series of two im portant ports in China, Shanghai Port and Ningbo Port are used for empirical analysis, and the results show the effectiveness of the proposed model.  相似文献   

7.
This paper addresses the problem of handling the uncertainty of demand in aone-supplier-one-retailer supply chain system. Demand variation often makes the real productiondifferent from what is originally planned, causing a deviation cost from the production plan. Assumethe market demand is sensitive to the retail price in a nonlinear form, we show how to effectivelyhandle the demand uncertainty in a supply chain, both for the case of centralized-decision-makingsystem and the case of decentralized-decision-making system with perfect coordination.  相似文献   

8.
This paper investigates the feedback control of hidden Markov process(HMP) in the face of loss of some observation processes.The control action facilitates or impedes some particular transitions from an inferred current state in the attempt to maximize the probability that the HMP is driven to a desirable absorbing state.This control problem is motivated by the need for judicious resource allocation to win an air operation involving two opposing forces.The effectiveness of a receding horizon control scheme based on the inferred discrete state is examined.Tolerance to loss of sensors that help determine the state of the air operation is achieved through a decentralized scheme that estimates a continuous state from measurements of linear models with additive noise.The discrete state of the HMP is identified using three well-known detection schemes.The sub-optimal control policy based on the detected state is implemented on-line in a closed-loop,where the air operation is simulated as a stochastic process with SimEvents,and the measurement process is simulated for a range of single sensor loss rates.  相似文献   

9.
Command Decision Simulation (CDS) is not only an important and difficult issue in the field of simulation, but also a technique issue to be tackled in the course of collective Modeling and Simulation in Joint Operations Experiment Center. CDS can give support to all kinds of simulation. Using computer to realize the Blue side's command deci- sion automatic execution in the operation training simulation system can improve training effect. Using computer to realize the lower level command unit's automatic command deci- sion can help to reduce the number of controllers and release them from heavy work. It can also enlarge simulation scale and increase the freedom of the simulation entity especially the command entity, thus enhance the authenticity and credibility of the simulation. Ac- cording to the command decision structure and the Joint Intention Theory, the thesis puts forward the method of making use of Coordination Matrix (CM) to realizing cooperation among the entities in CDS and constructs the calculation sketch of Task Execution, Task Monitoring and Task Replanning. At the same time, the thesis brings forward the CDS structure vision based on Partial Global Planning(PGP). As CM is an indispensable part of combat simulation, the theory and the method of CDS will become an important part for the theory of Combat Simulation.  相似文献   

10.
在CTCS-3级列控系统的仿真平台中,应答器作为关键的地面设备,需要给车载等地面设备提供定位信息和线路信息等,以保证列车的正常安全行驶,所以在正确的位置给车载设备发送应答器报文信息是很重要的。提出了一种仿真平台中减小应答器定位查找误差的算法,阐述了该算法的实现过程。仿真结果表明该算法减小了应答器定位查找的误差,是仿真中保证列车正常安全行驶的一种重要算法。
Abstract:
In the simulation platform of CTCS-3 system,the balise is the indispensable above-ground equipment which sends the localization information and the line information to the on-board equipment to guarantee traffic safety.It is very important to send the balise text in the correct position and opportunity.An algorithm was developed to reduce the localization search error when a balise was found in the simulation platform and this algorithm’s realizing process in the simulation platform was elaborated on.The result of the simulation indicates this algorithm can reduce the localization search error for balises,which is important in guaranteeing the normal and safe operation for trains.  相似文献   

11.
模糊供应链批量生产计划问题   总被引:1,自引:0,他引:1  
描述了模糊单位生产成本、模糊生产能力以及模糊需求下的分布式多工厂供应链批量生产计划问题。根据不同的决策准则建立了模糊期望值模型和模糊相关机会约束规划模型。当模糊变量是三角模糊数时,讨论了模糊规划模型的清晰等价形式,并采用遗传算法给出了求解模型的具体步骤。最后通过一个数值例子验证了方法的有效性。  相似文献   

12.
This paper considers the economic production quantity (EPQ) problem with backorder in which the setup cost, the holding cost and the backorder cost are characterized as fuzzy variables, respectively. Following expected value criterion and chance constrained criterion, a fuzzy expected value model (EVM) and a chance constrained programming (CCP) model are constructed. Then fuzzy simulations are employed to estimate the expected value of fuzzy variable and α-level minimal average cost. In order to solve the CCP model, a particle swarm optimization (PSO) algorithm based on the fuzzy simulation is designed. Finally, the effectiveness of PSO algorithm based on the fuzzy simulation is illustrated by a numerical example. This research is supported by the National Natural Science Foundation of China under Grant No. 70471049.  相似文献   

13.
针对导弹部队多波次作战任务规划问题, 依据无人机的实时数据, 构建了基于路径的多层规划模型, 并设计了模型的算法求解流程。使用遗传算法与禁忌搜索混合算法, 得出了任务规划中的最优路径规划, 并在此基础上进行了冲突的消除。通过仿真案例表明, 用无人机协同配合导弹部队作战, 实时传输作战数据, 能够解决战场信息模糊不确定的问题; 使用多层规划模型能够为导弹多波次规划作战的路径进行科学的决策和选择。利用遗传算法和禁忌搜索混合算法, 能够避免局部最优导致无法输出结果的现象。  相似文献   

14.
基于不确定规划的供应链网络设计模型与算法   总被引:6,自引:0,他引:6  
利用不确定规划,根据决策者的要求,对供应链网络设计问题进行建模.并采用由随机模拟、模糊模拟以及遗传算法相结合的混合智能算法来求解,最后给出了生活中的实际例子来说明模型和算法的正确性和高效性.  相似文献   

15.
针对模糊环境中资产收益和换手率均为模糊变量的投资组合问题, 考虑了资产组合的基数约束、投资比例的边界约束、资产的流动性以及分散化程度约束, 建立了一个以资产组合收益、偏度最大, 同时资产组合风险、不确定性以及模糊性最小为目标的多准则投资组合优化模型. 然后, 利用加权极大-极小模糊目标规划方法将所提出的模型转化为单目标规划问题, 进而设计了一个遗传算法来对其进行求解. 最后, 通过一个实例来阐明所提出模型的实用性以及算法的有效性. 研究结果表明: 本模型能够有效地刻画不同投资者的投资意图, 所设计的算法是有效的.  相似文献   

16.
基于遗传算法的模糊优化研究   总被引:5,自引:0,他引:5  
针对约束条件、系数和优化变量均为模糊数形式的线性和非线性全模糊优化问题 ,利用模糊数积分排序方法 ,提出了基于遗传算法的模糊优化问题求解方法 ,在该方法中对优化变量采用模糊数编码(每个变量用三个实数编码 ,对应三角模糊数中的 a,b,c) ,最后通过全模糊线性和非线性优化算例 ,验证了方法的有效性.  相似文献   

17.
对于卫星链路参数在复杂空间环境中存在不确定性的问题,研究了一种基于不确定链路参数的卫星网络路由算法。首先,采用三角模糊数描述链路参数的不确定性;在此基础上,建立卫星网络多约束路由模型;然后,设计保证路径有效性的遗传操作,通过遗传算法对路由模型进行求解;最后,通过仿真分析表明,该算法可以在复杂环境中实现高效路由,在平均时延、时延抖动和丢包率等方面有较好的效果。  相似文献   

18.
围绕机会阵雷达(opportunistic array radar, OAR)阵列动态机会组阵的资源管理问题,以面向多任务为应用需求背景,针对机会布置在平台3D空间多个区域内的天线单元,提出了一种基于现代数学不确定性理论中的相关机会约束规划方法用于机会阵方向图综合。该方法建立在不确定性理论和模糊数学基础上,考虑OAR大量天线单元空间位置分布的不确定性和各单元激励(开/关)状态的不确定性,用模糊随机变量来刻画不确定环境中的模糊性和随机性,在天线资源受约束的不确定条件下,建立不确定规划模型来实现方向图综合。并设计将遗传算法和模糊随机模拟算法相结合的智能混合优化算法以获得模型的最优解。最后利用仿真实例验证了不确定规划模型和所设计算法的可行性和鲁棒性。  相似文献   

19.
一种基于三角模糊数多指标信息的聚类方法   总被引:1,自引:0,他引:1  
针对一类特征指标值及指标权重均为三角模糊数的多指标信息聚类问题,提出了一种新的最大树聚类分析方法。首先对三角模糊数多指标信息聚类问题进行了描述;然后依据传统的基于数值信息的最大树模糊聚类分析方法的基本思路,给出了解决三角模糊数多指标信息聚类问题的计算步骤。最后,通过算例说明了本文给出的聚类方法。  相似文献   

20.
针对战场物资配送中带硬时间窗车辆路径问题的多重模糊性,基于模糊可信性理论建立了多目标模糊期望值模型,提出了一种改进的约束多目标粒子群优化算法。算法采用基于相位空间思想的实数编码方式,提出了带优秀不可行解动态记忆机制的非支配解构造方法,基于自适应栅格和拥挤距离的混合多样性策略维护非支配解集,改进了个体向导更新方式,提高了算法的收敛性能,同时引入局部搜索和变异算子避免算法早熟。仿真实验表明了模型的合理性和算法的有效性。  相似文献   

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