A Theory of Secure Mobile Computation with Confined Movement and Communication

An extended π calculus was introduced to deal with secure movement and intercommunication between agents. The system extends Nomadic-π with objective migration primitive and confined region which serves as annotation labels of agents and channels. The confined region labels were used to uniquely identify the constraints on the migration and communication of agents, with the labels, the agents could be confined in a secure subsystem and the inter-agent communication could be confined between agents located on trusted sites during computation. The operational semantics for the calculus was given out, and a type system which enforces security properties called confined migration and confined communication was developed.     

柴油机轴系扭振振幅异常分析与故障处理

通过对R16V280ZJ柴油机试验台轴系的扭振计算和实测对比,分析试验台位轴系扭振产生振幅异常的原因,从而有效实现故障排除。     

高架桥连续刚构箱梁满堂支架的稳定性计算与控制

较详细阐述了高架桥连续刚构箱梁满堂支架的稳定性计算的方法和施工控制。     

天山新二号双线铁路隧道断层坍方处理设计计算

天山新二号双线铁路隧道施工中,由于地质情况不明发生了断层破碎带坍方。根据坍体形态,对空腔地段采用明洞通过,对堆碴地段采用固结注浆大管棚支护、侧壁导洞法开挖,顺利地通过了坍体。文章对管棚结构承受的荷载及受力进行了探讨和检算,对明洞结构的护拱及缓冲层进行了设计计算论证。     

CRH型电动车组制动距离计算与监控装置制动模式曲线设计

通过对CRH型电动车组有关制动距离计算参数的分析研究，提出一套基于制动减速度的动车组制动距离计算方法和计算公式，同时对动车组LKJ列车监控装置制动模式曲线设计的有关问题作了论述。     

计算智能理论及其在RITS中的应用

从分析生物智能、人工智能和计算智能的发展过程及研究本质出发,给出了目前计算智 能的概念综述了主要研究方法和研究现状,特别指出了计算智能理论技术面临的挑战,并进行 了展望,最后分析了计算智能理论应用技术以及在铁路智能运输系统中的应用.     

基于改进MPS方法的三维时域水弹性计算模型

本文在作者已有的二维改进MPS(Moving Particle Semi-implicit)方法基础上进行了三维拓展(主要包括三维自由面粒子判断),并通过将计算得到的三维溃坝问题结果与文献中实验结果相对比,验证了所发展模型的准确性。在结构响应计算方面,将刚性和柔性模态耦合并计及相互影响。在此基础上,将流体和结构部分通过迭代方式耦合,从而实现强流固耦合计算。最后,应用上述模型对涉及大刚体位移叠加弹性变形的三维方梁的强非线性时域水弹性问题进行了计算,验证了模型对此类问题的有效性。     

GIS-aided prediction for sea-ice distribution

A method of applying the geographic information system (GIS) to predict sea-ice distribution is proposed. The prediction computations are performed using the distributed mass/discrete floe (DMDF) model. The GIS is used to prepare the initial data for the DMDF model, and to display the simulation results together with a digital map and observational data for evaluation and further use. Two areas in the Arctic Ocean were selected to test the computations in this study. The results of the case studies show that this method can help with (1) free-area and free-scale prediction fitting for various purposes, (2) a high-resolution output to provide more detailed data, and (3) a reasonable combination of different data sets to make the best use of the information obtained. The results also suggest that the DMDF model is a good simulation of the ice motion not only for large-scale but also for local-scale predictions. Received: March 19, 2002 / Accepted: June 20, 2002 Acknowledgments. This study was financially supported by the Japan Science and Technology Corporation. The SSM/I sea-ice data were obtained from the EOSDIS NSIDC Distributed Active Archive Center (NSIDC DAAC), University of Colorado at Boulder. The authors thank the persons concerned. Address correspondence to: H. Yamaguchi (yama@fluidlab.naoe.t.u-tokyo.ac.jp)     

一种分布式交通控制算法及其计算机仿真

针对城市交通拥塞这一困扰世界各国的难题,分析了城市交通拥塞的原因,并提出了解决思路。给出了分布式交通拥塞控制算法并进行了仿真。认为该算法基本能实现城市智能交通控制,解决城市交通拥塞问题。     

饱和软粘土地基沉降速率的计算方法

为了探讨饱和软粘土地基沉降速率的计算方法,根据饱和软粘土应变固结度与应力固结度的近似关系,推导出地基沉降速率的计算公式,提出了饱和软粘土地基沉降速率的计算方法,所得结果与工程实测数值相符。结果表明:软土层超固结比对计算结果有较大影响,计算时应根据地质资料及地区经验合理选择各土层超固结比。