嵌入式船舶网络综合网关的设计

为满足船舶综合信息平台对全船各子系统或设备网络互联的需求,针对某型船网络结构,基于W7100A网络微处理器+CAN控制器SJA1000,设计船舶网络综合网关,给出具体的软硬件设计方法。移植μC/OS-II嵌入式操作系统,使数据传输具有很高的实时性,实现船舶以太网、CAN和RS485三种网络的互联及数据的共享,该网关全部采用双冗余的网络结构,具备很高的可靠性。     

从历法改革看北宋天文管理的成效与问题

本文综合政治、社会、文化、技术等因素从历法工作角度探讨了北宋天文管理的成效与问题,并得出结论认为:管理竞争机制的引入、技术管理标准的完善、政府的支持与有效组织,确实有利于天文学的创新发展,但不恰当的行政干预会妨碍技术管理制度的执行,进而阻碍天文学的发展.     

苏北农村居民出行特征分析及交通对策研究

采用抽样问卷实地调查的方法对苏北五市(徐州、淮安、连云港、宿迁、盐城)的2000位农村居民进行了出行调查,从出行频率特征、出行方式、出行目的、出行距离和出行时空分布等方面对苏北农村居民出行特征进行了详尽分析.针对苏北农村居民出行存在的问题,提出具体的交通发展建议.     

皖北城镇群城际轨道线网方案研究

为了加速皖北地区城市化进程,推动皖北城镇群发展,对皖北城镇群城际轨道交通线网方案进行研究探讨。根据皖北地区城镇群的特征,采用点线面分析为基础的综合分析规划法,分为主骨架构建和线网扩充两个层次进行城际轨道线网规划,提出契合城镇体系布局以及未来发展方向的城际轨道交通线网方案。研究形成"双核、六射、一连一贯通"的城际轨道线网形态,有力支撑皖北地区一体化发展。     

CRH2型动车组国产化BCU通信网关的设计与实现

介绍了CRH2型动车组国产化制动控制单元(BCU)与车辆信息终端装置之间的通信网关,提出了网关硬件系统的实现方案,并给出其主程序以及各个子程序的设计思路,实现了BCU与车辆信息终端装置之间的通信。并通过将国产化BCU在CRH2型动车组BCU试验台试验,对设计网关功能进行验证。     

数据库中间件在铁路综合应用系统中的应用

提出利用数据库中间件技术,探讨铁路综合应用跨异种数据库的数据消费实现方法.     

Examining quick delivery at an affordable cost by the NSR/SCR-combined shipping in the age of Mega-ships

ABSTRACT

The Mega-ships, the maximum containerships represented by 20,000TEU-class (LOA:400m, Breadth: 60m, Draft: 16m) which are able to transit both the Malacca Strait and the Suez Canal, have emerged in 2013, aiming at lower shipping cost by economy of scale. At the same time, they inevitably increased port calls in a rotation to collect more cargo demand, resulting in the longer transit time than ever before. Taking this trend into account, the authors proposed the quick delivery scenario between East Asia and Northwest Europe by the NSR (Northern Sea Route)/SCR (Suez Canal Route)-combined shipping, of which 4,000 TEU ice-class containership transits the NSR during the summer season and the SCR in the wintertime, based on a year-round scheduled operation. The quick delivery scenario gives the shorter transit time at an affordable shipping cost depending on the NSR navigable season length. However, the quick delivery scenario cannot avoid uncertainties in navigation especially via the NSR in the summer season, due to rough weather, sea ice, low visibility and icing in the icy water section of the NSR. The authors preliminarily concluded that a year-round scheduled operation of the NSR/SCR-combined shipping will be secured, if the practical navigation schedule is appropriately prepared.     

Interaction of HLA and TCP/IP subsystems in C^3I system

Aiming to the fact that the distribution modules of the C31 simulation system originally developed based on TCP/IP protocol has to be compatible with the present HLA （High Level of Architecture） rules, three methods for implementing the interaction of HLA and TCP/IP subsystems are presented to make the original TCP/IP modules directly used in the HLA-based C^3I system without redevelopment. The three methods are agent method, middlewarc method and gateway method. Moreover, the implementation of gateway method via VC ＋＋ as well as the key technology is discussed.     

HSRP在舰载IP网络可靠性设计中的应用

针对舰载IP网络系统的可靠性需求,根据HSRP协议理论,提出了一种多路径冗余网关解决方案,使得舰载IP网络与陆地网络中心数据交换时,能实现路由冗余和负载均衡,同时可以跟踪海-地无线网络干线的工作状态,在冗余的无线链路上也能实现冗余备份和负载均衡,从而保证舰载IP网络系统内高可靠性要求业务的不间断运行,有效提高海-地广域网络系统的可用性。     

陕北地区低湿条件下混凝土碳化深度及影响因素研究

为深入分析导致混凝土碳化的各类因素,降低碳化的破坏作用,通过对陕北地区低湿条件下几座隧道的二次衬砌,桥梁的桥墩、承台、桥台的碳化深度进行测试,分析低湿环境下混凝土强度、龄期、光照、结构物位置与碳化深度的关系,得到适合该地区的碳化深度预测公式xc=0.312 51t和y=0.103t0.713。在降低混凝土碳化的不利影响方面,通过隔绝空气以及调整混凝土配合比,可以保证在密实度得到改善的混凝土中建立一个适度的高碱环境,以减少或避免碳化对混凝土耐久性的破坏。