协同设计中以实体为中心的并发操作控制机制

并发操作控制机制是协同设计中的重要问题，其实质是解决操作冲突并提供无冲突操作；而一致性、响应性和并发性是其中三个重要但互斥的需求．因此，并发操作控制机制的焦点是在保证一致性前提下，以最小响应时间和最大并发程度，解决操作冲突．文中提出了并发操作控制机制的重要设计准则，并进一步提出一种以实体为中心的并发控制机制及其形式化定义和总体实现．该机制以冲突消除取代冲突避免，通过本地操作、服务器端操作确认和复制同步三个步骤，实现松散WYSIWIS原则；其中本地操作改善响应性；服务器端操作确认最大化并发性；复制同步保证一致性．

Entity-Centric Concurrent Manipulation Control Scheme for Cooperative Design

Study of concurrent manipulation control scheme is an important problem for the cooperative design. The essence of the problem is how to solve manipulation confliction and provide confliction-free manipulation. Consistency, responsiveness and concurrency are three important but mutually exclusive requirements for concurrent manipulation control. Hence, the focus of concurrent manipulation control scheme is how to solve manipulation confliction with minimum response time and maximum concurrency under the condition of consistency. This paper proposes several design considerations for concurrent manipulation control scheme, presents an entity-centric concurrent manipulation scheme based on a series of formalized concepts and depicts its overall implementation in detail. This scheme adopts confliction elimination rather than confliction avoidance and implements relaxed WYSIWIS through local manipulation, server-end manipulation validation and replica synchronization. Local manipulation improves responsiveness; server-end manipulation validation maximizes concurrency and replica synchronization guarantees consistency.