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題 名 | 行動式位置相關物件資料庫與查詢語法=A Mobile Location-dependent Object Database and Its Query Language |
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作 者 | 段裘慶; 楊鍵樵; | 書刊名 | 臺北科技大學學報 |
卷 期 | 34:2 2001.09[民90.09] |
頁 次 | 頁85-100 |
分類號 | 312.49 |
關鍵詞 | 行動資訊系統; 位置相關物件; 連續式查詢; 行動式位置物件查詢語法; Mobile information systems; Location-dependent object; Continuous query; LdOQL; Java OQL; |
語 文 | 中文(Chinese) |
中文摘要 | 因應行動式無線網路與行動式資訊系統的發展趨勢,本文提出一「行動式位置物件查詢語法」(LdOQL),於應用上提供更具便利性與多樣性的查詢類型,以方便行動用戶端能隨時隨地對位置物件資料作有效地搜尋。 LdOQL條件子句可用以設定1.被查詢物件所駐留的位置條件"locObjRegion"、2.連續式多次查詢的時段與區段存活條件"actQuyRegion"和"actQuyPeriod"、3.關聯變化的模式與門檻條件"actQuyMode"等。同時,為了增進LdOQL的實用性,也制定一套LdOQL-Java OQL語句轉譯處理,以促使轉譯後的Java OQL(ODMG 3.0)查詢句可適用於現行物件資料庫管理系統的運作環境。 |
英文摘要 | Mobile computing and wireless networks is one of the trends in networking technology. The location of a mobile host in the wireless networks needs to be detected for fetching necessary information or data to the mobile host. In this paper, we proposed a novel query language, location-dependent object query language (LdOQL), which is based on and expanded from the Object Query Language (OQL). The mobile clients could issue LdOQLs to query the related information of desired location-dependent objects conveniently and efficiently, in spite of, where and when they are roaming in the wireless environment. Through LdOQL, the clients could set the location conditions with "locObjRegion" to limit the range of objects queried. Also, the clients could use "actQuyRegion" and "actQuyPeriod" as the living conditions to restrict the active range and lifetime of continuous query, respectively, moreover, use "actQuyMode" to set the mode of context change and its threshold for refreshing query. In addition, we design a translation procedure for translating LdOQL into the format of Java OQL defined by ODMG 3.0. This translated Java OQL could be effectively processed in the current object database management environment. |
本系統中英文摘要資訊取自各篇刊載內容。