臺灣博碩士論文加值系統

現今網際網路的快速發展，人們對於網路的依賴性越來越高，當使用者需要某項服務或某些檔案時，需要先經由網路中特定的伺服器來查詢後，再向這些提供服務的主機或設備來取得，這種資訊和資源取得的方式就是目前常見集中式架構，稱為主從式架構。但是，在主從式架中存在一些潛在的缺點，如擴充性、額外的費用、容易遭受攻擊和可靠度等問題。由於主從式架構存在著這些問題，所以當點對點計算的提出，引起大家的重視和廣泛的討論。在點對點的網路環境中，使用者彼此檔案或服務的交換是可以不經由伺服器的指引，即可輕鬆且隨意尋找到所需的資源，也就是說，在點對點的架構中，資源是可以隨時、隨地且隨意的來取得，並且不需由大型的伺服器來記錄這些資訊。然而，在結構化點對點架構之中，雖然可以提供完整檔案名稱之快速搜尋，但對於關鍵字查詢則無法提供如此快速之查詢速度。對於關鍵字的查詢目前已經有提出一些改良方法，但是在這些架構之中，不是需要在搜尋的過程中事先建立關鍵字的查表，要不就是發生檔案存在確搜尋不到的結果。也就是說，在這些架構之下，往往會發生節點的額外負擔和查詢失敗的現象。
所以，在本篇我們將提出階層式分類的架構，其每個節點不需記錄著所有分類的資訊，只需在每個類別的領導者記錄著其下一層的分類資訊即可。如此一來，透過少量而不增加節點的負擔下，不僅可以提供更快速的完整檔案名稱查詢，更能提供快速之關鍵字查詢。除此之外，在此架構之下，若檔案存時，關鍵字的查詢可準確找出檔案的所在位置。不僅如此，由於個人喜好的因素，每個使用者都有特定喜愛的檔案類型，而在階層式分類的架構中，已經將相同類型的使用者區分為同一類。所以，當彼此有需求相同檔案類型時，將可以用如同區域網路的方式來互相交換所需的資源。最後經由實驗的驗證，透過階層式分類的架構，不僅可以降低傳統結構化之搜尋次數，更能提供準確且快速之關鍵字查詢。

Nowadays, people became more rely to internet due to the rapid growth of internet. Users need to access to specify servers to search for required services or documents before obtain the resources from the providing server. This method was the common centralized architecture in obtaining resources. However, there are several potential drawbacks of centralized architecture like expanding problems, extra costs, vulnerable to attack and reliability problems. Hence, the proposed of peer-to-peer computing was well discussed and pay attention by everyone. In peer-to-peer networks, there are direct change of resources and documents between users without the access to centralized server. Users can access to desired resources in anywhere and anytime. Although structured peer-to-peer networks is able to provide rapid search of complete file name, however, it is unable to provide rapid search in keyword searching. Although there is a great improvement in keyword searching for several existed methods, however, a keyword lookup table need to be build before the searching process. Moreover, existed files may not be found in the searching process.
Hence, we proposed a resource classification mechanism with hierarchical architecture in this paper. Each of the nodes in this architecture no needs to record the info of classification except the leader of each classification which only needs to record the classification info of the next level. Hence, the proposed method can increase the searching performance without increase the number of nodes and additional burden of node. Moreover, existed files may be found accurately in the searching process. In addition, users are classified into certain group with the same interests due to the specify interests of each user. So, users with the same interests are able to interchange resources within the same network. From the experiments, we found that the proposed hierarchical classification architecture not only reduce the searching time of traditional peer-to-peer structure, but also provide the accurate keyword searching rapidly.

摘要 I
Abstract III
目錄 V
圖目錄 VII
第1章 簡介 1
1.1 研究背景 1
1.2 研究動機 2
1.3 研究目標與研究方法 4
1.4 論文架構 5
第2章 相關研究 6
2.1 非結構化網路 6
2.2 結構化網路 7
2.2.1 CONTENT ADDRESSABLE NETWORK架構 7
2.2.2 CHORD NETWORK架構 9
2.2.3 PASTRY NETWORK架構 10
2.2.4 TAPESTRY NETWORK架構 12
2.3 階層式網路常見之架構與搜尋方法 12
2.3.1 SUPER-PEER架構 13
2.3.2 檔案分類法 14
2.3.3 分散式雜湊表 15
第3章 建構結構化階層式架構 17
3.1 結構化分類的建立 19
3.2 階層式架構的建立 22
3.3 階層式分類之結構化的建構 24
3.4 服務的搜尋 27
3.4.1 己知完整名稱和分類資訊之查詢 28
3.4.2 關鍵字查詢和分類資訊之查詢 31
第4章 實驗與模擬 33
4.1 已知完整檔案名稱之搜尋次數 34
4.2 關鍵字查詢之搜尋次數 36
4.3 模擬結果分析 38
第5章 結論 41
參考文獻 42
Publication List of Chao-Hsiang Yang 45

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