智慧型手機的發展十分快速，已經是近年來最熱門的電子產品。隨著越來越便宜的價格以及運作更有效率的硬體設備供消費者選擇，使得智慧型手機的使用者越來越多，這同時也造成手機竊盜的事件增加；更由於智慧型手機的便利，越來越多人不是在現實世界中與朋友或家人做聯繫，反而是使用智慧型裝置來溝通。如此一來人與人彼此之間的直接互動減少了，這些現象已經隱約的造成犯罪率的提升。
　　本篇論文提出一個系統架構，用來監控小孩子的社交生活情況，在整個系統運作期間，我們不會打擾使用者的操作。我們是為了避免因為父母親給予孩子更多的自由空間而造成小孩子被誘拐或是被誤入歧途的可能性；於是我們在手機端開發了應用程式來監聽孩子們的社交活動，並定時將蒐集到的相關資料回傳到遠端伺服器，只要父母有疑慮，即可申請其孩子的對應資料來觀察，以預防犯罪事件發生。

Smartphones are getting more accessible with affordable price and wide selection of hardware specifications. So, the amount of users who has a smartphone is getting bigger and bigger. Therefore, more and more people talk to their friends or send them messages on the phone rather than just visit in reality world. This phenomenon leads the rise of the crime rate according to some reports. It is obvious that why the crime rate is rising. Because the criminals communicate to each other more easily and quickly than before. Also, the teenagers are more easier to go astray.

In this thesis, we propose an architecture for crime prevention with monitoring their social activities. There are two features in the architecture. One is that to implement on the mobile phone. We use this part to listen for the call events and receiver to the short messages. The other is implemented on computer as a remote server which is used to reserve the important information obtained from users. And we also improve the information for future work.

Chapter 1: Introduction
1.1 Motivation
1.2 Contribution
1.3 Organization
Chapter 2: Background
2.1 Smartphone
2.2 Android
2.3 Sox
Chapter 3: Related Work
3.1 Official Way
3.2 Third Party Approaches
3.2.1 First Approach
3.2.2 Second Approach
Chapter 4: System Architecture and Design
4.1 Application of the Mobile Phone Site
4.2 Services
4.2.1 Call Event Service
4.2.2 SMS Event Service
4.3 The Recorder
4.4 Remote Server Site
4.4.1 Audio Processing
Chapter 5: Implement
5.1 Building Environment
5.2 The Structure of Android Application
5.3 Phone Call Events
5.3.1 Incoming Call Events
5.3.2 Outgoing Call Events
5.4 SMS Events
5.5 Recorder
5.6 Remote Server
5.7 Process
5.8 Summary
Chapter 6: Analysis
6.1 The Effectiveness of Audio Processing
6.1.1 Experiment Purpose
6.1.2 Experiment Design
6.1.3 Experiment Result
6.2 Power Consumption
6.3 Portability
Chapter 7: Conclusion
7.1 Conclusion
7.2 Future Work

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