面向历史洪水的三峡水库削峰能力量化分析

为了量化分析三峡水库防洪库容的削峰能力,采用一种优化-拟合框架,对三峡水库历史入库洪水进行分析计算。通过设置三峡水库调度期内不同的最高水位方案,采用动态规划算法,对不同类型的入库洪水进行优化求解,得出三峡水库不同防洪库容方案下的洪峰削减流量,再用回归分析,量化三峡水库防洪库容的削峰能力。结果表明:对于多年场次洪水,三峡水库动用的防洪库容与其削减洪峰流量的相关关系可划分为3种类型:“先增后平”型、“分段递增”型和“线性递增”型。前2种类型存在拐点,建议动用在阈值以下的防洪库容,以充分发挥其高效削峰能力;最后1种类型可以结合洪峰削减目标,合理规划防洪库容进行调度。分析结果可为三峡水库科学合理有效分配防洪库容提供参考。

A structural comparison of measurement-based admission control algorithms

Measurement-based admission control （MBAC） algorithm is designed for the relaxed real-time service. In contrast to traditional connection admission control mechanisms, the most attractive feature of MBAC algorithm is that it does not require a prior traffic model and that is very difficult for the user to come up with a tight traffic model before establishing a flow. Other advantages of MBAC include that it can achieve higher network utilization and offer quality service to users. In this article, the study of the equations in the MBAC shows that they can all be expressed in the same form. Based on the same form, some MBAC algorithms can achieve same performance only if they satisfy some conditions.