近年來雲端運算在學界與業界都是一個熱門的議題，越來越多的雲端資料服務提供可信賴的與靈活的資料儲存服務給使用者。如何提供服務達到使用者的服務層級協議(service level agreement ; SLA)，對於服務提供者與使用者是很重要的議題。服務提供者必須排程每一個使用者的任務，並且決定這些任務應該被哪個伺服器服務，使得服務提供者可以服務更多的使用者。因為這個任務排程問題在雲端儲存中是一個NP-hard的問題，我們提出啟發式演算法解決這個問題，與最佳解相比，我們的方法有不錯的效能，並且我們的演算法在頻寬分配率跟隨機的方法比好了平均百分之十，在請求服務率跟隨機的方法比好了平均百分之十五。

Abstract ii
List of Contents iii
List of Figures iv
List of Tables v
Chapter 1 Introduction 1
Chapter 2 Related Work 4
2.1 Cloud Storage Architecture 4
2.2 Content Delivery Network 6
2.3 Task Scheduling Problem 7
Chapter 3 Task Scheduling Algorithm 9
3.1 System Model and Architecture 9
3.2 Algorithms for Task Scheduling Problem 12
3.2.1 Algorithm for MKAR 13
3.2.2 Algorithms for UFP 15
Chapter 4 Simulation Results 19
4.1 Simulation Results for MKAR 19
4.2 Simulation Results for UFP 23
Chapter 5 Conclusion 29
References 30

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