| 摘要: |
| 最近几年，在软件工程界内部有一种趋势，这就是开发以面向具体领域的ＣＡＳＥ环境．作为这样的一种ＣＡＳＥ工具，ＸＹＺ系统是由一时序逻辑语言ＸＹＺ／Ｅ和一组基于该语言的工具集构成．在ＸＹＺ系统中有很多的工具，它们被用来满足不同的需要．众所周知，ＳＤＬ（ｓｐｅｃｉｆｉｃａｔｉｏｎａｎｄｄｅｓｃｒｉｐｔｉｏｎｌａｎｇｕａｇｅ）是电信领域中的一个国际标准语言，而且有关基于该语言的环境已在开发，但是有关该语言的验证工作，特别是利用有关时序逻辑语言进行验证的工作还不多．作为一种尝试，本文将利用ＸＹＺ系统中的一个子系统ＸＹＺ／ＶＥＲＩ，对ＳＤＬ所描述的有关电信领域中的例子进行验证． |
| 关键词: 时序逻辑 电信系统 SDL语言 XYZ系统 程序验证 CASE工具 程序转换 |
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| 基金项目:本文研究得到国家自然科学基金和北京邮电大学程控交换机技术与通信网国家重点实验室资助. |
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| APPLICATION OF XYZ SYSTEM IN TELECOMMUNICATION FIELD |
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Shen Wuwei,Tang Zhisong
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| Abstract: |
| B+ -trees are considered standard organization for indexes in database systems. The concurrent control mechanism on B+ -trees has a great effect on the performance of DBMS supporting multi-users. A variant of B+ -tree called e-B+ -tree(elastic B+ -tree) is presented in this paper. Then, the safe nodes and operations on e--B+ trees are defined and the moment of reconstruction of e-B+tree is regulated. All these measures not only reduce the overhead for maintaining the e--B+ tree and the time spent on locking, but also decrease the frequency of splitting and catenating operation. Therefore, the degree of concurrency of operations on e-B+tree and efficiency of the database system can increase by a big margin. |
| Key words: Temporal logic telecommunication SDL （specification and description language） XYZ program verification CASE tools program transformation. |
