A Structured Hypertext Data Model with Versioning for Engineering Documents

Hypertext involves linking related information blocks together to form a network. It is suitable to access information in a nonlinear fashion with a flexible structure. However, when the hypertext technique is applied to manage mass data such as engineering documents, the large number of nodes and links involved can cause problems such as data access navigation and versioning control. This paper introduces a structured hypertext data model with a version control mechanism.In our model, the structure node is defined and can be used to reduce the number of visible nodes during browsing through the logical structure of the hypertext network. As a result, the network structure becomes clearer, relatively easier to navigate through the network and to prevent users from disorientation during data access or browsing operations. The structure node provides a high level abstract mechanism, implies more knowledge and supports visual presentation of the hypertext network. In this model, the version node is a special kind of structure node which is used as a means to support versioning. Compared with other hypertext systems or models, the proposed model is better suited to the needs of engineering data management. A formal description of this model also is presented along with a description of the write-multiple Optical Disk based Electronic Archives Management System (ODEAMS), which was developed on the basis of this model.