离散系统仿真复习.docVIP

仿真元素之间关系：system,model,simulation System-A collection of entities Model-set of assumptions about how the system works 仿真模型分类-Classification of simulation models Static- dynamic Deterministic-stochastic Continuous-discrete 离散事件仿真模型-Most operational models are dynamic,stochastic,and discrete Will the system work as intended? (Evaluation and prediction) Why doesnt it work? (Bottleneck determination and optimization) Which is the best alternative? (Comparison and sensitivity analysis) 目的-Objectives: must define the kind of decisions that must be questions. 仿真研究的步骤-Steps In A Simulation Study： Problem Formulation-Model Building-Data Collection-Coding-Verification-Validation-Experimental Design-Production Runs-Analysis Of Results-Document Program and report results-Implementation 离散事件仿真系统-DESS（Discrete-event simulation system) Modeling of a system as it evolves over time by a representation where the state variables change instantaneously at separated points in time 事件-Event: Instantaneous occurrence that may change the state of the system 仿真模型的组成元素-entity/attribute/state/event/activity/process Type of entities: Temporary(临时的)entities,Permanent(永久的)entities Activity(活动)The duration of an entity to maintain between 2 events.The start and are caused by event. Process(进程)整个过程，涵盖两个活动 事件表-Event List Event type of the future events Event time Related parameters Simulation Clock：TNOW 事件优先机制-Event-advance Mechanism Event scheduling(事件调度法) Activity scanning(活动扫描法) Process interaction(进程交互法) 流程图模块：创建creat,清除dispose,操作process,决策decide,批量batch,分离separate，赋值assign,记录record 数据模块：entity,queue,resource,variable,schedule,set 稳态统计分析：Steady-state statistical analysis 1.重复删除法-Truncated Replications Advantages: Simple —aside from warmup, the same as for terminating simulations Get truly IID observations — important not only for variance estimation and confidence-interval construction Disadvantages: No completely reliable method to identify an appropriate warmu