Delay Tolerant Networks (DTNs) is a dynamic topology network, in which connection durations of each link are variable and paths between two nodes are intermittent. Most of protocols which are widely used in traditiona...Delay Tolerant Networks (DTNs) is a dynamic topology network, in which connection durations of each link are variable and paths between two nodes are intermittent. Most of protocols which are widely used in traditional wireless network are not suitable for DTNs. DTN adopts store-and-forward mechanism to cope with the problem of intermittent path. With limited storage of each node, it is a challenge for scheduling nodes’ transmission to avoid overflow of nodes’ buffers. In this paper we propose an optimal transmission scheduling algorithm for DTN with nodes’ buffer constraints. The object of the optimal algorithm is to get maximum throughput. We also present an algorithm for obtaining suboptimal transmission schedules. Our solution is certified through simulation, and it is observed that our solution can improve network performance in the aspects of avoiding overflow and increasing network throughput.展开更多
溢流坝下游收缩断面水深 hc 的计算对水工消能设计十分重要． 目前常用的方法有试算法、图解法和迭代法，这些方法计算精度不高，人工计算量大或要求较高的计算数学的理论知识等，不便于在生产实际中推广应用． 为此，把 hc 的计算问题...溢流坝下游收缩断面水深 hc 的计算对水工消能设计十分重要． 目前常用的方法有试算法、图解法和迭代法，这些方法计算精度不高，人工计算量大或要求较高的计算数学的理论知识等，不便于在生产实际中推广应用． 为此，把 hc 的计算问题归结为非线性优化问题，用作者研制的加速遗传算法 （AGA） 来处理． 应用 AGA 方法的实例计算结果说明 AGA 比常用方法简便 计算精度高且具有通用性．展开更多
文摘Delay Tolerant Networks (DTNs) is a dynamic topology network, in which connection durations of each link are variable and paths between two nodes are intermittent. Most of protocols which are widely used in traditional wireless network are not suitable for DTNs. DTN adopts store-and-forward mechanism to cope with the problem of intermittent path. With limited storage of each node, it is a challenge for scheduling nodes’ transmission to avoid overflow of nodes’ buffers. In this paper we propose an optimal transmission scheduling algorithm for DTN with nodes’ buffer constraints. The object of the optimal algorithm is to get maximum throughput. We also present an algorithm for obtaining suboptimal transmission schedules. Our solution is certified through simulation, and it is observed that our solution can improve network performance in the aspects of avoiding overflow and increasing network throughput.
文摘溢流坝下游收缩断面水深 hc 的计算对水工消能设计十分重要． 目前常用的方法有试算法、图解法和迭代法，这些方法计算精度不高，人工计算量大或要求较高的计算数学的理论知识等，不便于在生产实际中推广应用． 为此，把 hc 的计算问题归结为非线性优化问题，用作者研制的加速遗传算法 （AGA） 来处理． 应用 AGA 方法的实例计算结果说明 AGA 比常用方法简便 计算精度高且具有通用性．
