System simulation technolgy which including three activity - system modeling ， simulation modeling and testing by simulation has almost exited 60 years ， and it has been extensive used in many fields such as electric power ， transportation ， communications ， chemical industry and nuclear power , etc . some oversea corporations have developed special simulation software since 1970s 包括系统建模、仿真建模和仿真试验三个基本活动的系统仿真技术已经有近60年的历史，因其具有节约人力、物力、快速和方便等诸多优点而得到认可，在电力、交通运输、通信、化工和核能等领域得到了越来越广泛的应用。
Therefore , it is great significance to achieve the targets on making a good job of p . e . teaching in rural schools , which make students obtain basic p . e . theories , grasping proper p . e . skills , learning scientific methods of body - building , keeping lifelong habit of physical training , so as to promote students " growth , further health , strengthen constitution , develop physical quality and raise basic action capability 切实搞好农村学校的体育教学工作，使学生获得基本的体育理论知识，掌握一定的体育运动技能，学会科学锻炼身体的方法，养成终身锻炼的习惯，以便达到促进学生身体生长、发育、增进健康、增强体质、发展身体素质和提高基本活动能力的目标就具有深远的意义。
Based on the domestic and international research of learning evaluation , this paper brings up 5 principles to build such a new evaluation system , they are : ( 1 ) the purpose is not a distinction , but to promote the development of students . ( 2 ) the basic way is not confirmation , but to promote communication . ( 3 ) the realization of learners " development depends on their again right own consideration 这一部分首先结合新课程改革的评价理念提出了5条评价原则， ( 1 )构建评价体系的目的不是区分，而是促进中学生在数学学习方面的转变性发展； ( 2 )评价体系的基本活动方式是淡化确认，加强对话； ( 3 )评价体系不是系统的控制，而是通过学习者的自我反思而实现； ( 4 )评价体系中对评价结果的表现形式不再是简单的分数和等级； ( 5 )评价体系需要创设一个批判性与支持性的开放环境。
In this model , the concept of version set is introduced , version set includes the concept of scm system in common use , such as components , repositories , workspaces , variant set , revision histor _ ies etc . feature logic is used for the base of describing version set in this paper , the boolean expression that composed of ( feature : value ) versus is used for expressing common or independent version character , and operations such as intersection , union , and complement are executed on version sets in order to express and generalize the basic activity of scm 该模型引入了版本集的概念，版本集包括常用的构件、库、工作空间、变种集、修订版历史等。论文使用特征逻辑作为描述版本集的基础，通过( feature ： value )对的属性组成的布尔表达式来表示公共或独立的版本性质，并对版本集进行交、并、补等操作以表达和概括scm的基本活动。由此可以描述变更和工作空间的管理。
It has better practicability and is easy to communion between teachers and students , share the resources and cooperating work . the paper work mainly includes : by investing the current computer aided teaching system based on c / s , it compared the characters of the c / s mode with p2p mode and summed up the advantages of the computer aided teaching system based on p2p ; by discussing the mechanism of aided teaching based on p2p , it discussed the new characters in the process of computer aided teaching system design and some important technique which can be used aiming at p2p environment ; it has researched , analyzed and designed the computer aided teaching system based on p2p ( p2pec ) 本论文所做的工作有:对当前基于c / s模式的计算机辅助教学系统调查和研究,比较c / s模式和p2p模式各自的特点,总结基于p2p网络的计算机辅助教学系统的优点;探讨基于p2p网络的辅助教学机制,针对p2p环境,对辅助教学系统设计过程中的一些新特点和可以采用的若干重要技术进行深入的讨论;对基于p2p的网络辅助教学系统p2pec进行研究、系统分析、总体设计;对p2pec系统及其子系统进行具体设计,详细阐述其模块的设计思想;对p2pec系统中实现的基本活动组、网上自主调课、网上答疑、课件协同制作等子系统的设计做了详细的讨论。
