中文摘要：

信息系统的合成与分解是数据库合成与分解的数学模型之一．本文基于信息系统中的优势关系讨论序信息系统的合成与分解的属性特征等问题．给出了对象合成序信息系统、属性合成序信息系统的概念，研究了原序信息系统与合成序信息系统的协调集及属性特征之间的关系；定义了序信息系统上的对象子序信息系统、属性子序信息系统，进而讨论了任一序信息系统与其分解生成的对象子序信息系统和属性子序信息系统的属性特征之间的关系．

英文摘要：

The composition and decomposition of an information system is one of the main mathe- matical models for describing the composition and decomposition of the data base. In this paper, the attribute characterizations of the composition and decomposition of an ordered information system are discussed on the basis of a dominance relation. By defining object and attribute composed ordered information systems, relationships of consistent sets and attribute characterizations between the composed ordered information systems and the original ones are first investigated. Then for any ordered information system, the sub-ordered information systems for objects and attributes are proposed, and the attribute characterizations between them are shown.