Algorithmic Issues in Power Management by Speed Scaling (APM)

移动的设备的新技术，如3G和Wi-Fi，带来了新的生活改变用户体验。然而，这种发展可能会受到电池寿命的阻碍，例如，使用3G通信可以将移动的电话的通话时间缩短高达75%。电池容量无法跟上设备电力需求的持续增长。此外，装置操作产生大量热。一般来说，设备的功率越大，产生的热量就越多。过热会损害电子设备的寿命。因此，功率管理对现代计算设备施加了重要的设计约束。为了在不显著牺牲性能的情况下降低能耗，“能量感知”成为一个至关重要的概念：系统应该只提供所需的服务，以避免多余的能耗。动态电压/速度缩放（DVS）成为管理功耗的常用技术，例如，来自AMD、Intel和Transmeta的当前处理器允许处理器以各种处理器速度操作。DVS的动机是由于众所周知的立方根规则，该规则规定消耗的功率大致是操作速度的立方。仅仅拥有支持DVS的处理器并不能解决问题，因为最重要的问题是如何动态调整处理器的速度，以最小的能量和温度保持性能？虽然已经提出了一些算法解决方案，但大多数都假设处理器可以以任何（无限）速度运行，这显然不是实际情况。此外，到目前为止所考虑的模型优化了能量或温度，但不是两者都优化。目前的提案旨在提供算法解决方案，以促进更强大但节能的设备。具体目标包括1.建立了一个精确的能量和温度有效的热交换抽象模型; 2.设计具有数学上可证明的性能保证的算法; 3.该项目的成功将对延长移动的设备的电池寿命产生影响，从而改善服务（例如，多媒体，它可以支持。博士的经验黄女士特别就工作排程进行初步研究，她对能源效益限期排程的初步研究为项目奠定良好基础，预期对项目的成功至关重要。

New technologies for mobile devices like 3G and Wi-Fi has brought new life changing user experiences. However, this development can be hindered by battery life, for instance, using 3G communication can shorten the talk time of mobile phones by up to 75%. Battery capacity is not able to catch up with the continuous growth of power requirements for devices. Furthermore, a large amount of heat is generated by device operation. In general, the more powerful the device is, the more heat is generated. Overheating can damage the life of electronic devices. Therefore, power management has imposed important design constraints on modern computing devices. To reduce energy consumption without sacrificing performance significantly, energy awareness'' becomes a crucial concept: a system should only deliver the required service so as to avoid superfluous energy consumption.Dynamic voltage / speed scaling (DVS) becomes a common technique to manage power consumption, e.g., current processors from AMD, Intel and Transmeta allow the processors to operate at various processor speeds. The motivation of DVS is due to the well known cube-root-rule which states that the power consumed is roughly the cube of the operating speed. Simply having processors that support DVS does not solve the problem because the most important question is How to dynamically adjust the speed of processor to maintain performance with the minimal energy and temperature?'' Although some algorithmic solutions have been proposed, most of them assume that the processor can operate at any (unbounded) speed, which is obviously not the case in practice. Furthermore, the models considered so far optimize either energy or temperature but not both. The current proposal aims at providing algorithmic solutions so as to facilitate more powerful, yet energy effective, devices. Specific objectives include1. developing an accurate abstract model of energy and temperature efficient scheduling,2. designing algorithms with mathematically provable performance guarantees, and3. providing a comprehensive evaluation of the proposed algorithms.The success of this project will impact on extending the battery life of mobile devices thus improving the services (e.g., multimedia) that they can support. The experience of Dr.\ Wong on job scheduling, in particular, her preliminary study on energy efficient deadline scheduling serves as a good foundation and is expected to be crucial for the success of the project.