目標物覆蓋(Target Coverage)在無線感測網路中是最重要的議題之一，本論文考慮一目標物監控的場景，其存在許多我們所感興趣的目標點(Point of Interest, POIs)，分散於監控區中，且每個POI依照其位置的不同而對監控品質(Quality of Monitoring, QoM)具有不同的重要性，需要不同數量的感測器長期對其進行覆蓋。本論文所考慮的感測器具有太陽能充電能力，隨機佈建於監控區中，對POI進行覆蓋，因感測器須定期仰賴太陽能充電，且其進行充電時將不進行感測工作，因此，每個感測器須規律於感測與充電模式間切換。對每一POI而言，其瞬間的監控品質又仰賴於多個感測器的監控，因此，感測器排程演算法的優劣，將決定POI的QoM。本論文所提出之感測與監控排程機制，對每個感測器進行感測及充電的排程，透過感測器間的輪流充電及合作監控，使感測器達永續生存及提昇監控品質的雙重目標。相較於研究[14]，實驗結果顯示，本文提出之排程機制，可在確保感測器達永續生存的條件下，有效提升並平衡POIs之QoM。

Target coverage is an important issue of wireless sensor networks and has been received a lot of attention in the past few years. Recent studies have shown that energy harvesting is essential for sensor networks in some specific situations, because it is costly and hard to maintain the wireless networks if the sensors’ battery was frequently replaced. As a result, this paper addresses the target coverage problem for the solar-powered sensor networks, and this paper also consider that the POIs would have the different importance since they are distributed in different places over the network environment. In the considered WSN, each sensor can either recharge its battery or monitor the point of interest (POI) at the same time. To make the WSN perpetual and balance the quality of target monitoring, this paper proposes two efficient sensor activation schedules while guarantee the target coverage and the POIs which with the higher importance will have the higher QoM. In addition, the proposed activation schedules can guarantee that all POIs can be well monitored even during the nighttime. In the performance study, it presents that the proposed mechanism outperforms the existing mechanisms in term of QoM balance index of POIs, decrease the range of the POIs’ QoM.

目錄
圖目錄  IV
表目錄  V
第一章、簡介	1
第二章、相關研究	5
第三章、網路場景與問題描述	9
3.1網路環境	9
3.2充耗電模型	10
3.3感測模型	12
3.4問題描述	13
第四章、演算法	18
第五章、模擬	35
5.1 Simulation Model	35
5.2 Performance Study	36
第六章、結論	41
參考文獻	42
附錄-英文論文	45

圖目錄
圖(一)：感測狀態與剩餘電量的關係	11
圖(二)：Elfes sensing model	12
圖(三)：感測器在白天時的工作週期分配	22
圖(四)：針對各POIs的工作週期	24
圖(五)：監控品質全距之比較	37
圖(六)：平均監控品質之比較	38
圖(七)：不同預留電力，白天及夜晚平均QoM的差距	38
圖(八)：Path-loss指數對於POIs獲得的QoM的影響	39

表目錄
表格一：本論文與太陽能相關研究之比較	7
表格二：模擬實驗之相關參數	35

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