Agent理论在舰船机电设备协同控制中的应用

舰船控制技术对于保障船舶的运行安全起着重要作用,特别是在现代复杂的船电控制系统中,众多的机电设备需要高度集成在有限的空间内。因此,为了保证所有船舶设备能够正常工作,必须对这些设备的运行状态进行实时的监控。本文采用基于Agent理论的船舶设备状态监测和故障诊断技术,能够有效提高船舶设备的安全性能。本文首先对Agent理论的基本原理进行分析,通过建立对应的船舶机电控制矩阵模型,优化机电协同系统的响应流程。最后,通过将Agent技术运用到协同函数中,对整个系统的性能进行仿真与分析,取得较好效果。     

基于Agent的决策支持系统研究

随着计算环境日益向分布式和开放式的方向发展,传统决策支持系统结构不便于扩充、无法与Internet上巨大信息资源紧密集成、与用户交互方式单一等局限日益明显,而Agent概念的提出及其相关理论和技术的发展为克服上述缺陷提供了可能性.提出了一种基于Agent的决策支持系统结构,探讨了其中各个Agent的结构、功能及实现技术,以及多Agent之间的协调策略,并构建了原型系统,显著地克服了上述不足.     

A multi-objective approach for Dynamic Airspace Sectorization using agent based and geometric models

A key limitation when accommodating the continuing air traffic growth is the fixed airspace structure including sector boundaries. The geometry of sectors has stayed relatively constant despite the fact that route structures and demand have changed dramatically over the past decade. Dynamic Airspace Sectorization is a concept where the airspace is redesigned dynamically to accommodate changing traffic demands. Various methods have been proposed to dynamically partition the airspace to accommodate the traffic growth while satisfying other sector constraints and efficiency metrics. However, these approaches suffer from several operational drawbacks, and their computational complexity increases fast as the airspace size and traffic volume increase. In this paper, we evaluate and identify the gaps in existing 3D sectorization methods, and propose an improved Agent Based Model (iABM) to address these gaps. We also propose three additional models using KD-Tree, Bisection and Voronoi Diagrams in 3D, to partition the airspace to satisfy the convexity constraint and reduce computational cost. We then augment these methods with a multi-objective optimization approach that uses four objectives: minimizing the variance of controller workload across the sectors, maximizing the average sector flight time, and minimizing the distance between sector boundaries and the traffic flow crossing points. Experimental results show that iABM has the best performance on workload balancing, but it is restrictive when it comes to the convexity constraint. Bisection- and Voronoi Diagram-based models perform worse than iABM on workload balancing but better on average sector flight time, and they can satisfy the convexity constraint. The KD-tree-based model has a lower computational cost, but with a poor performance on the given objectives.     

Agent based model for dynamic ridesharing

Dynamic ridesharing involves a service provider that matches potential drivers and passengers with similar itineraries allowing them to travel together and share the costs. Centralized (binary integer programming) and decentralized (dynamic auction-based multi-agent) optimization algorithms are formulated to match passengers and drivers. Numerical experiments on the decentralized approach provides near optimal solutions for single-driver, single-passenger cases with lower computational burden. The decentralized approach is then extended to accommodate both multi-passenger and multi-driver matches. The results indicate higher user cost savings and vehicle kilometers traveled (VKT) savings when allowing multi-passenger rides. Sensitivity analysis is conducted to test the impact of the service provider commission rate on revenue and system reliability. While short term revenue can be maximized at a commission rate of roughly 50% of each trip’s cost, the resulting drop in system reliability would be expected to reduce patronage and revenues in the longer term.     

Simulation based population synthesis

Microsimulation of urban systems evolution requires synthetic population as a key input. Currently, the focus is on treating synthesis as a fitting problem and thus various techniques have been developed, including Iterative Proportional Fitting (IPF) and Combinatorial Optimization based techniques. The key shortcomings of these procedures include: (a) fitting of one contingency table, while there may be other solutions matching the available data (b) due to cloning rather than true synthesis of the population, losing the heterogeneity that may not have been captured in the microdata (c) over reliance on the accuracy of the data to determine the cloning weights (d) poor scalability with respect to the increase in number of attributes of the synthesized agents. In order to overcome these shortcomings, we propose a Markov Chain Monte Carlo (MCMC) simulation based approach. Partial views of the joint distribution of agent’s attributes that are available from various data sources can be used to simulate draws from the original distribution. The real population from Swiss census is used to compare the performance of simulation based synthesis with the standard IPF. The standard root mean square error statistics indicated that even the worst case simulation based synthesis (SRMSE = 0.35) outperformed the best case IPF synthesis (SRMSE = 0.64). We also used this methodology to generate the synthetic population for Brussels, Belgium where the data availability was highly limited.     

Web语义的分类和缓存

针对Web信息查询缺乏对查询概念的相关语义这一问题，引入一种本体的形式化模型，通过引入本体内聚度等概念建立本体中概念间的语义关联，从而便于对常识知识的处理，并作为语义扩展及缓存的依据，由此建立起查询的上下文关联及联想，给查询带来较好的适应性。     

基于XML技术的多Agent模型的设计与实现

当前,Agent具有消息接收与发送、目标协调求解、行为计划与调度、动作执行与监控、以及内部状态和资源管理等功能.本文提出了一种基于XML技术的多Agent模型,用来解决网络分布式的异构数据环境中的数据查询.在模型中各个Agent既能独立完成各自的功能又可以相互合作,以XML语言为信息处理和交互的载体共同实现目标.     

基于移动代理的分布式无线传感器网络管理

无线传感器网络正日益成为一种用于各类应用中的重要技术。无线传感器网络由成百上千个传感器结点构成,这些传感器结点具有传感、处理及无线通信的能力。但迄今为止,无线传感器网络及其应用在发展的同时,并未考虑对无线传感器网络管理的解决方案。作为一种动态拓扑的无线移动网络,相对于常规网络的管理而言,无线传感器网络的管理有它自身的特点和要求。本文首先分别介绍了无线传感器网络以及移动代理的基本概念和特点,分析研究了无线传感器网络管理的自身特点和需求。然后在此基础上,提出了一种基于移动代理的分布式无线传感器网络管理的体系结构,其中包括网络管理体系结构的工作原理,以及被管理的传感器结点的结构模型。最后讨论研究了在此网络管理体系结构中的传感器结点的分簇要求及特点。     

基于多Agent的集装箱码头生产调度系统建模研究

集装箱码头的生产调度决策是在港口资源有限的条件下,对设施设备进行优化调度,以提高工作效率的问题,涉及因素多而且具有离散性和动态性的特点.文中提出了基于MAS集装箱码头的智能生产调度系统的思路及其结构框架,该系统考虑了泊位、岸桥、集卡、堆场及闸口等设施和设备的资源利用,介绍了Agent的结构和功能,Agent群之间的通信机制和协商机制,并以泊位调度Agent为例,说明了调度Agent群的工作机制.     

基于信号博弈的相邻交叉口TSCA交互分析

将相邻交叉口 TSCA 间交互看作不完全信息动态博弈,分析了其博弈交互过程,建立了相邻两交叉口 TSCA交互的信号博弈模型,通过算例分析了相邻交叉口 TSCA 交互的精炼贝叶斯纳什均衡策略。最后通过仿真分析了此模型的有效性。该模型为分析相邻交叉口交通信号协调控制提供了新的思路。