無線感測網路(Wireless Sensor Networks, WSNs)是由眾多低成本且體積小的感測器(Sensor)及少數(通常一個)資料收集站(Sink Node)所組成，這些感測器被密集地散佈在需要偵測的區域，對環境進行監控與感測。應用的範圍很廣，從基本的農業動植物監控、醫療與健康照護到智慧生活、軍事用途等，甚至可進一步進行綠色節能等應用。但絕大多數的感測器由電池供電，且更換電池不易，致使感測器電量一旦耗盡，則視同死亡。因此，如何延續無線感測器網路的生命期，一直是學者們所共同努力的目標。隨著近年來的無線充電技術逐漸成熟，行動充電車可在有效的距離內替感測器進行無線充電。本研究擬針對規則佈建的無線感測器網路，探討充電車對感測器的行動充電策略。本研究將考慮感測器在感測任務及傳輸任務間的電量分配比例、行動充電車的數量、行進方向與移動速度，以期達到較佳的事件捕捉率。最後，透過效能評估，本研究將歸納較好的充電策略參數設定，使無線感測網路達到較好的事件監控效能。

Emerging wireless charging technology has received much attention in the wireless sensor network (WSN) because it achieves the perpetual operation of WSNs and forms the wireless rechargeable sensor network (WRSN). This thesis considers the WRSNs where plenty of static sensors are regularly deployed to monitor the suspicious events. Mobile chargers aim to re-charging energy to sensors and collect their sensing data in an efficient way such that high monitoring quality and small data reporting delay can be achieved. This thesis proposes four charging strategies for mobile chargers and then conducts analyses for the event detection quality of each strategy. Moreover, this thesis proposed an efficient dispatching algorithm for mobile chargers to enhance the event detection ratio with a number of mobile chargers. Based on the performance evaluations, this thesis generalizes better parameter settings, including energy allocation between tasks of sensing and transmitting, and movement speed of mobile chargers, to improve the event detection quality.

Table of Contents
List of Figures	IV
List of Tables	V
Chapter 1. Introduction	- 1 -
Chapter 2. Related Works	- 6 -
Chapter 3. Problem Statement	- 9 -
3.1 Network Model	- 9 -
3.2 Problem Statement	- 11 -
Chapter 4. Energy-charging Strategies for Event Detection	- 13 -
4.1 Mobile Charging Strategy by Constant Velocity	- 16 -
4.2 Enhance Mobile Charging Strategy by Constant Velocity	- 22 -
4.3 Mobile Charging Strategy by Constant Angular Velocity	- 24 -
4.4 Hybrid Mobile Charging Strategy	- 26 -
4.5 Efficient Charger Dispatching Algorithm	- 28 -
Chapter 5. Performance Evaluation	- 32 -
Chapter 6. Conclusions	- 41 -
References	- 42 -

List of Figures
Fig. 1. Network environment.	- 10 -
Fig. 2. The example of a disconnected set.	- 20 -
Fig. 3. MC-H scenario.	- 26 -
Fig. 4. The procedure of Efficient Charger Dispatching Algorithm.	- 31 -
Fig. 5. Different scale and Event detection ratio.	- 33 -
Fig. 6. Different scale and Algorithms on Event detection ratio.	- 34 -
Fig. 7. Impact of time to rendezvous between MC-CV and EMC-CV.	- 35 -
Fig. 8. Impact of event detection ratio between MC-CV and EMC-CV.	- 36 -
Fig. 9. Impact of different speed vi with the throughput of transmission data.	- 37 -
Fig. 10. Impact of different data size with the event detection ratio.	- 38 -
Fig. 11. Impact of different number of mobile chargers in EMC-CV.	- 39 -
Fig. 12. Impact of different number of mobile chargers in MC-CAV.	- 40 -

List of Tables
TABLE I	- 32 -

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