近年來，隨著各種可攜式電子裝置(手機,筆記型電腦，PDA)成為大眾化的消費型電子產品，由於可攜式電子裝置大多於嵌入式即時系統，因此操作時間成為一個重要的設計指標，低消耗能量變成設計主要考慮的問題。其中一個低功耗設計的方式是動態電壓頻率調整(Dynamic voltage frequency scaling)，藉由任務排程和同時調降電壓、頻率，來達到低消耗能量。我們將提出一個演算法將可估算系統的負載(loading)和讓系統趨近於理想消耗能量的狀態。模擬的結果將說明，我們所提出的演算法將會優於目前相關研究的演算法，並且能將能量消耗降低趨近於理論值約3%。

Various portable devices (cell phone, laptop, and PDA) are popular consumer electronics in recent years. Since these portable devices are designed with real-time embedded systems, the operation time of the electronic products becomes one of important design factors. Low energy consumption becomes one of the major issues of the embedded systems. One of approaches is through dynamic voltage frequency scaling (DVFS). In DVFS, we need to schedule tasks and adjust the voltage and frequency simultaneously. We proposed an algorithm that predicts system loading and let the system reach a better state of energy consumption. Our simulation results show that our algorithm outperforms other know schemes and close to the theoretical lower bound by a 3 percent.

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