Introduce searching engine technology of " event inspection " and define the modular description language in respect of its intrusion patterns , as well develop the corresponding rules parser 采用了“事件檢測”引擎技術(shù),并定義了一套入侵特征模式描述語言及相應(yīng)的規(guī)則語法解釋器。
Therefore new attacks can be logged in modular description language and added to the attacks logging database . the description languages together with the event inspection function make the system ' s expandability and upgrading possible . 3 這樣,可以用模式描述語言描述新的攻擊并增加到攻擊特征模式庫中,同時增加新的事件檢測引擎來識別此攻擊,保證了系統(tǒng)的可擴(kuò)展性要求,方便升級。
Aiming at this problem , the main research issues and achievements in this paper are as follows : bi - directional data transformation between rdb and xml with semantic constraints preserved for most of existing researches on static data transformation between xml and rdb , dtd is taken as the schema description language for xml , and the semantic constraints are often lost during the transformation process . to overcome these disadvantages , the author adopts xml - schema , a standard schema description language proposed by w3c to replace dtd , as the description method owing to its more powerful functions than dtd , and of course with the syntax much more complicated . after analyzing the constraints characteristics in both xml - schema and relational schema , a semantic constraints - preserved algorithm is proposed which can realize the bi - directional schema mapping between rdb and xml through a formalized description of xml based on regular tree and a general expression for relational schema based on direct graph approach 保留語義約束的xml與rdb雙向靜態(tài)數(shù)據(jù)轉(zhuǎn)換技術(shù)現(xiàn)有研究大多采用dtd ( documenttypedefinition ,文檔類型定義)作為xml的模式描述語言,并且在模式映射過程中丟失語義約束信息,本文分析了xml - schema ( xml - schema采用與dtd完全不同的語法,數(shù)據(jù)描述能力更強(qiáng)同時也更為復(fù)雜,已被w3c確定為替代dtd作為xml模式描述語言的標(biāo)準(zhǔn))及關(guān)系模式的語義約束特征,通過基于正則樹的xml形式化描述方法以及基于有向圖的一般關(guān)系模式表示方法的研究,建立保留語義約束的xml - schema與關(guān)系模式的雙向模式映射算法,實現(xiàn)了xml與rdb的雙向數(shù)據(jù)轉(zhuǎn)換,較好地解決了xml與rdb在靜態(tài)數(shù)據(jù)轉(zhuǎn)換層面的數(shù)據(jù)集成問題,可有效滿足企業(yè)大量rdb數(shù)據(jù)面向xml的發(fā)布以及與日俱增的xml數(shù)據(jù)存入rdb的應(yīng)用需求。