一种基于模糊聚类的资源发现策略

Chord是一款较为成功的P2P资源发现算法,但在网格环境中由于网格资源固有的特性,影响了其发现效率。针对网格资源的复杂多样性以及很难精确分析其相似程度,提出利用模糊聚类的方法对资源进行属性划分,将资源分成多个资源相似集合,结合Chord路由算法,相似资源存放在较近的Peer上组织成2维Chord结构。实验结果表明,与原Chord路由算法相比,该策略能有效降低查寻时间,资源发现效率明显提高。     

移动视频业务的自适应资源预留方案

提出了一个拓扑独立且自适应的资源预留方案用以向移动视频业务提供服务品质保证.建议的方案通过研究移动节点累积的运动历史,总结出其运动特点,进而对节点的运动趋势进行预测.基于预测的结果,正在进行的移动视频业务所需的资源在移动节点未来最可能访问的子网中被预留.所提出的方案在向用户提供满意的移动视频业务的同时,保证了网络资源的充分利用,并降低了预留阻塞的可能性.     

An artificial neural network based decision support system for solving the buffer allocation problem in reliable production lines

One of the major design problems in the context of manufacturing systems is the well-known Buffer Allocation Problem (BAP). This problem arises from the cost involved in terms of space requirements on the production floor and the need to keep in mind the decoupling impact of buffers in increasing the throughput of the line. Production line designers often need to solve the Buffer Allocation Problem (BAP), but this can be difficult, especially for large production lines, because the task is currently highly time consuming. Designers would be interested in a tool that would rapidly provide the solution to the BAP, even if only a near optimal solution is found, especially when they have to make their decisions at an operational level (e.g. hours). For decisions at a strategic level (e.g. years), such a tool would provide preliminary results that would be useful, before attempting to find the optimal solution with a specific search algorithm.     

Transition Motion from Ladder Climbing to Brachiation with Optimal Load-Allocation Control

Abstract

This paper describes the transition motion from ladder climbing to brachiation for a multi-locomotion robot (MLR). The MLR has versatile modes of locomotion, such as biped walking, quadruped walking, brachiation and ladder climbing. The transition is a challenging motion, because the environmental boundaries change and the robot has to switch the form of its locomotion depending on its surroundings, situations and purposes. The robot supports itself with three end-effectors that maintain its stability, while one hand transfers from a rung on the vertical ladder to a new rung behind the robot for brachiation. A closed kinematic chain is formed by the robot links and the ladder. In this case, if the number of position-controlled active joints is greater than the number of the chain’s degrees of freedom, an internal stress appears because of unavoidable position errors. The huge internal stress may lead some motors to become overloaded. Since the safety of each motor is very important for a serial-link robot, a load-allocation algorithm is proposed to balance the loads of the joint motors. The algorithm is verified through experiments.     

Aeroservoelastic model based active control for large civil aircraft

A modeling and control approach for an advanced configured large civil aircraft with aeroservoelasticity via the LQG method and control allocation is presented.Mathematical models and implementation issues for the multi-input/multi-output(MIMO) aeroservoelastic system simulation developed for a flexible wing with multi control surfaces are described.A fuzzy logic based optimization approach is employed to solve the constrained control allocation problem via intelligently adjusting the components of output v...     

一类输电网损分摊方法的积分路径相关性简析

利用功率微增量进行求和是目前输电损耗分摊中的一类代表性方法。文中讨论了该类方法所存在的积分路径相关性问题,表明等步长划分积分区间本身即是一类特殊且并无明显理论依据的求和(积分)路径,至少到目前为止,尚无相关理论可以支持这类特解在理论体系上的恰当性。对该类方法而言,如何克服其所存在的求和路径相关性问题仍然是一个开放的、有待解决的问题。     

采用潮流跟踪法的输电费分摊算法

研究了在复杂电网内分摊输电线路的固定成本的方法。输电费分摊常用的方法有邮票法和MW—km法,前者较简单但没有考虑输电距离,不够公平;后者既考虑输送距离又考虑输送功率的大小,比较合理,但在复杂电网内分摊实现较困难。文中用一个5节点算例对潮流跟踪算法和直流灵敏度系数法进行了比较,结果证明前者物理概念清晰而且与平衡机节点位置的选择无关,所以推荐采用潮流跟踪法计算输电费的分摊。     

Adaptive resource allocation techniques in OFDMA using cross-layer architecture

This paper utilizes the cross-layer architecture to implement adaptive resource allocation in Orthogonal Frequency Division Multiple Access （OFDMA） based on the broadband wireless access system. According to the cross-layer architecture, the information in link layer is used for adaptive resource allocation in OFMDA. A new cross-layer adaptive resource allocation algorithm is developed which can guarantee the users to be in minimum average waiting time in link-layer and get the better spectrum utilization. Numerical results show that our scheme is appealing and can get about half of average waiting time less and 0.5 bps/Hz spectrum utilization more than the scheme in 1EEE802.16a.     

Resource Allocation Algorithm Based on PSO-GA for Multi-User OFDM System

In order to minimize the transmitted power in the multi-user orthogonal frequency division multiplexing (OFDM) system, a scheme combining the improved particle swarm optimization (POS) algorithm with genetic algorithm (GA) is proposed to optimize the sub-carriers and bits allocation. In the algorithm, a random velocity between the maximum and minimum particle velocity is used as the updating velocity instead of maximum or minimum velocity when the updated particle velocity is higher than the maximum particle velocity or lower than the minimum particle velocity. Then, the convergence population is used as the initial population of the genetic algorithm to optimize the sub-carriers and bits allocation further. Simulation results show that the transmitted power of the proposed algorithm is about 2 dB to 10 dB lower than that of the genetic algorithm, particle swarm optimization algorithm, and Zhang's algorithm.     

基于量子布谷鸟搜索的认知无线网络频谱分配

为了有效解决认知无线网络频谱分配的离散优化问题,将量子计算引入布谷鸟搜索算法,提出了一种新的组合优化算法——量子布谷鸟搜索算法。该算法使用量子鸟窝表征问题的多维解,通过Lévy flights随机游动方式和量子突变策略快速搜索到全局最优位置。通过使用基准函数验证了算法的高效性,并提出了一种基于量子布谷鸟搜索的认知无线网络频谱分配方法。然后与经典频谱分配算法在不同的网络效益函数下进行仿真性能比较。结果表明,所提出的频谱分配方法能够较快找到全局最优解,并且在不同网络效益函数下均优于已有的经典频谱分配算法。