Concurrency control has always been one of the most important issues in the design of synchronous groupware systems with fully-replicated architecture. An ideal strate- gy should be able to support natural and flexibl...Concurrency control has always been one of the most important issues in the design of synchronous groupware systems with fully-replicated architecture. An ideal strate- gy should be able to support natural and flexible human-to-computer and human-to-human interactions while maintaining the consistency of the system. This paper summarizes previ- ous researches on this topic and points out the deficiencies of the existing results. A novel semantics-based concurrency control framework, oodOPT is proposed. The main idea of the framework is to resolve conflicts by utilizing semantics of the operations and the accessed data objects. With this approach, complexities in concurrency control are shifted completely from application developers to the framework. Conflicts among operations on objects with different semantics and the strategies resolving these conflicts are analyzed. After describing the algo- rithm in full detail, the discussion ends up with a comparison with other related work and some considerations for open problems.展开更多
CoMEdiA is a groupware tool which enables co-authors to cooperatively produce hypermedia docu- ments.CoMEdiA allows co-authors to communicate their ideas,drafts,guidelines,constraints and annota- tions to other co-aut...CoMEdiA is a groupware tool which enables co-authors to cooperatively produce hypermedia docu- ments.CoMEdiA allows co-authors to communicate their ideas,drafts,guidelines,constraints and annota- tions to other co-authors.It uses a mix of communication patterns,media and document organization to enable co-authors to keep on exchanging information(remotely or face-to-face),improving passages and modifying notes until a final document is achieved.We did not concentrate on the depth but on the breath of the features.Our efforts were on integrating and coordinating concepts from collaboration, multimedia and hyper organization rather than on making a specialized system in any of them.We be- gan with the text medium and are now including bitmaps and raster images.Later sound and video will also be integrated.In this paper we describe and sustain the available capacities.展开更多
基金The work was supported by the National Natural Science Foundation of China under grant No.69773029 and theNational '863' High-
文摘Concurrency control has always been one of the most important issues in the design of synchronous groupware systems with fully-replicated architecture. An ideal strate- gy should be able to support natural and flexible human-to-computer and human-to-human interactions while maintaining the consistency of the system. This paper summarizes previ- ous researches on this topic and points out the deficiencies of the existing results. A novel semantics-based concurrency control framework, oodOPT is proposed. The main idea of the framework is to resolve conflicts by utilizing semantics of the operations and the accessed data objects. With this approach, complexities in concurrency control are shifted completely from application developers to the framework. Conflicts among operations on objects with different semantics and the strategies resolving these conflicts are analyzed. After describing the algo- rithm in full detail, the discussion ends up with a comparison with other related work and some considerations for open problems.
文摘CoMEdiA is a groupware tool which enables co-authors to cooperatively produce hypermedia docu- ments.CoMEdiA allows co-authors to communicate their ideas,drafts,guidelines,constraints and annota- tions to other co-authors.It uses a mix of communication patterns,media and document organization to enable co-authors to keep on exchanging information(remotely or face-to-face),improving passages and modifying notes until a final document is achieved.We did not concentrate on the depth but on the breath of the features.Our efforts were on integrating and coordinating concepts from collaboration, multimedia and hyper organization rather than on making a specialized system in any of them.We be- gan with the text medium and are now including bitmaps and raster images.Later sound and video will also be integrated.In this paper we describe and sustain the available capacities.
