中文摘要：

为简化双时态数据模型（BCDM）时态属性表达、减少存储空间、提高查询效率,按照双时态信息的3种表达形式,针对有效时间区间更新历史是否保留的两种情况,讨论双时态数据的合并描述、优化算法、合并传统双时态序偶为＂事务时间区间＋有效时间区间＂的表达机制,给出规范的BCDM双时态形式定义。复杂性分析表明,规范的BCDM双时态标签具有明显的低存储性和高查询效率。

英文摘要：

For simplifying temporal attributes expression of bitemporal concept data model（ BCDM）,reducing storage space and increasing querying efficiency,according to three expression forms of bitemporal information and aiming at two situations of whether or not to keep the update history of effective time intervals,we discuss the combination description of bitemporal data,the optimisation algorithm,and combine the traditional bitemporal ordered pair to the expression mechanics of＂transaction time interval ＋ valid time interval＂. At last,we present the standardised BCDM bitemporal formal definition. Complexity analysis indicates that the standardised BCDM label has obvious low storage property and high querying efficiency.