智能网格体系结构应用研究

人工智能技术研究的目的在于解决大型复杂的现实问题,而解决这类问题已超出单个主体的能力,多Agent系统就是在这种背景下产生的,智能网格系统(Agent Grid System)从某种程度上讲就是一个多Agent系统.本文以智能网格系统为主题,给出一套智能网格模型.     

后疫情时代基于XGBoost的铁路客运站客流量预测研究

进入"后疫情时期",铁路客流正逐步回升,但呈现较大波动,面对铁路提质增效的任务,准确预测客流量愈发重要.文章采用极端梯度提升(XGBoost,eXtreme Gradient Boosting)模型,以新冠肺炎疫情、天气和日期属性作为影响因素,选取上海站2016年1月1日—2020年7月27日客流量数据作为训练集和验证...     

基于遗传算法的天然气集输管网参数优化设计

以管道建设总费用为目标建立目标函数 ,以管道的稳态分析、各节点的流量、压力及管道压力限制等为约束条件 ,建立了天然气集输管网的参数优化设计模型。该模型属非线性离散化最优组合问题 ,采用遗传方法求解 ,并给出了计算机软件算法     

汽车灯配光镜CAD的数据结构及搜索方法

汽车灯配光镜是一种面形复杂，边界不完全规正的微透镜阵列，其数据结构及搜索方法是CAD软件实现的难点之一，本文给出一套可行的数据结构及搜索方法，经依此编制成的程序（MVHLD）对四种不同的前照灯所作的400多万条光线[1]的计算证实这套数据结构是合理的。搜集方法是可靠的。     

GIS-Based Grid Assessment Model of Shield Tunnel Conditions and Its Application北大核心CSCD

As the lack of guidancs for maintenance and repair of rail transit shield tunnels, this paper proposes a macroscopic method for grid assessment of shield tunnels. First, the tunnel serviceability index (TSI) is adopted as the tunnel condition assessment method and the results are compared with Chinese codes and the traditional fuzzy hierarchical comprehensive evaluation method. Second, based on the assumption that the factors affecting the conditions of the tunnels, such as the surrounding stratum environment, the structural overlying load and so on, are correlated spatially, the spatial variability theory is used for the grid assessment of shield tunnels. Finally, taking the Shanghai Rail Transit System as an example, the application results of the grid assessment method are described. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

华能营口电厂取水工程的流场数值模拟

华能营口热电厂取水工程二维水流数学模型采用嵌套网格的差分格式进行模拟计算,分析了不同取水位置对流场的影响。计算结果表明,该方法对取水口所在水域具有足够的网格分辨率,能够满足大范围海域边界条件验证的要求和工程所在河口水域流场的特征,同时又能满足工程局部水域计算精度的要求,具备边界控制准确、地形概化灵活、模拟精度合理和运算效率高等优点。     

基于改进遗传算法的舾装件托盘多载具协同拣选方法

为提升舾装件托盘的拣选效率,建立拣选过程的数学模型,提出一种基于改进遗传算法（Improved Genetic Algorithm,IGA）的舾装件托盘多载具协同拣选方法。针对遗传算法（Genetic Algorithm,GA）流程与实际拣选过程的差异,改进GA的初始化过程和染色体交叉方式,并对变异过程进行更贴近实际生产的修改。针对GA难以得到全局最优解的问题,采用变邻域搜索（Variable Neighborhood Search,VNS）策略降低陷入局部最优解的可能性。采用实例计算验证该算法的有效性,可优化传统舾装件托盘拣选方法。     

Equilibrium properties of taxi markets with search frictions

The equilibrium properties of an aggregate taxi market are investigated using a general bilateral searching and meeting function which characterizes the search frictions between vacant taxis and unserved customers. Three specific issues are analyzed for meeting functions that exhibit increasing, constant and decreasing returns to scale. Firstly, service quality in terms of customer wait/search time and average profit per taxi are examined jointly in relation to taxi fleet size, and a Pareto-improving win-win situation is identified, where an increase in taxi fleet size leads to improvements in both service quality and market profitability. Such a Pareto-improving situation is found to emerge if and only if the meeting functions show increasing returns to scale. Secondly, the properties of the socially optimal solution are examined. It is found that the taxi fleet size should be chosen such that the total cost of operating vacant taxis equals the total cost of customer waiting time multiplied by an asymmetric factor of the meeting function, and that taxi services should be subsidized at social optimum only when the meeting functions show increasing returns to scale. Thirdly, the Pareto-efficient services are examined for trade-offs between social welfare and profits in the light of partially conflicting objectives of the public sector and the private taxi firms using a bi-objective maximization approach. The taxi utilization rate and the customer wait/search time or service quality are proved to be constant along the Pareto frontier and equal to those at social optimum if the meeting functions show constant returns to scale. Extensions are made to the cases with increasing and decreasing returns to scale.     

基于信息网格平台的车载交通信息服务系统研究

随着移动计算和嵌入式技术的飞速发展，嵌入式自主导航车载系统正得到广泛的应用。本文提出了一种建立在信息网格平台上的车载交通信息服务系统。该服务系统后台依托上海交通信息网格这样一个强大的智能交通信息中心，为前台车载终端用户提供包括实时交通信息，动态路径决策，公共设施查询等高附加值的交通信息服务，克服了传统的自主导航车载系统为用户提供的信息服务单一，不能够提供实时动态交通信息的缺陷。本系统的车载终端硬件采用龙芯处理器，软件采用Linux操作系统和基于JAVA的开发环境。在对上海信息网格的关键技术和体系结构做了简要介绍之后，本文对前台车载终端系统的架构、硬件设施和关键功能的实现算法做了详细介绍，并给出了系统运行的效果和性能测试结果。