在無線感測網路中，感測器的電力供應非常有限，一般來說通常是由一般電池或者是太陽能電池供電，在這樣的能源限制下，感測器能夠運作的時間也相對受限，一旦網路中有感測器能量耗盡，則會導致不完整的網路感測覆蓋率。因此，網路的生命週期在第一個節點能源耗盡的情況即宣告終止。而在我們的研究中，利用環境讀數的相似性以及地域的鄰近性來做分群的依據，同時，我們提出的方法能夠有效的保護網路中虛弱的節點，而保護虛弱節點的同時也平衡網路中節點的能量消耗，使得整體網路的存活時間得以延長，最後的實驗則驗證了我們方法的成效。

The energy on each node in the wireless sensor network (WSN) is mainly consumed by sensing the environment as well as conveying or relaying the sensed data to sink. Once the resident energy in some sensor node is drained, it may cause an incomplete sensing coverage. The network lifetime is therefore assumed as the duration start from the moment when the network starts to work to the moment when the first node dies out of power. In this paper, the proposed scheme clusters nodes not only considering the similarity of reading data on each node but the similarity of node location. Meanwhile, by referring to the weakness in the resident energy and coverage of each node, the proposed scheme protects the weakest nodes first to balance the energy consumed on each node for extending the network lifetime. The evaluation result validates our proposed concept

論文摘要 I
ABSTRACT II
誌謝 III
目錄 IV
圖片索引 VI
表格索引 VII
第 1 章 緒論 1
第 2 章 背景知識 3
2.1 無線感測網路(Wireless sensor networks : WSNs) 3
2.2 近似資料收集(Approximate Data Collection) 4
第 3 章 定義 6
3.1 網路環境 6
3.2 定義及參數 8
3.3 節點覆蓋範圍 9
3.4 偏序關係 10
3.5 問題描述 12
3.6 虛弱節點保護 13
第 4 章 主要方法 15
4.1 R節點選擇方法 15
4.2 動態權重路由選擇方法 18
4.2.1 路徑建立階段： 19
4.2.2 資料收集階段： 22
4.2.3 路徑選擇階段： 22
4.2.4 工作階段： 24
4.3 排程機制 24
第 5 章 模擬結果 28
5.1 效能指標 28
5.2 系統及環境參數 29
5.3 實驗結果 29
5.3.1 EnC最差情況(Worst case) 30
5.3.2 EnC最佳情況(Best case) 31
5.3.3 EnC實驗情況統計 32
5.3.4 平均R節點選擇個數 33
5.3.5 加入路徑選擇機制(Path Selection)的效能成長 34
第 6 章 結論 35
參考文獻 37

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