A Distributed and adaptive framework for provisioning QoS in IPv6 networks

A distributed and adaptive framework （DAF） was proposed for provisioning quality of service （QoS） in IPv6 network. In DAF, per-flow admission control and resource reservation, in conjunction with a new IPv6 flow label mechanism, can be performed instantaneously in a fully distributed and independent fashion at the edge of network without hop-by-hop signaling. The flow label helps in resource reservation and packets forwarding for aggregated traffic on an edge-to-edge path basis. In addition, a bounded directional probing technique for DAF was designed to reconfigure resource reservation adaptively between every pair of edge router for aggregated traffic according to the fluctuation of its traffic load. The simulation results show that DAF provides QoS guarantees to individual flows with minimal overhead, as well as keeping the scalability characteristic like DiffServ.     

Numerical research on wave-making resistance of trimaran

A 3D rankine panel method was developed for calculating the linear wave-making resistance of a tri-maran with Wigiey hulls. In order to calculate the normal vector and derivative of the body surface accurately,non-uniform rational B-spline (NURBS) was adopted to represent body surface and rankine source density.The radiation condition is satisfied using the numerical technology of staggered grids. Numerical results showthat the linear wave-making resistance of the trimaran can be calculated effectively using this method.     

舰船大风浪中纵向强度标准应用

由于海军舰艇部队使命任务的复杂性和多样性,舰船遭遇大风浪的频率也大大增加。因此,计算舰船在风浪中的纵向总强度从而估计航行舰船强度风险非常重要。本文探讨舰船在风浪中的总纵向强度和疲劳强度的累计损伤度方法模型,提出衡量舰船大风浪中纵向总强度的衡量标准。     

基于CIVIL 3D的防波堤工程量计算分析

本文基于CIVIL 3D建立某海外港口防波堤模型,解决在原有防波堤基础上新建防波堤后的工程量计算问题。本文将介绍整个建模过程和思路,通过软件分析得到新建防波堤的精准工程量,并通过构建原有防波堤BIM模型对比实际已建防波堤的工程量验证模型的正确性,最后通过对比传统防波堤计算方法表明基于CIVIL 3D软件的BIM建模更加精准有效。     

下承式半结合板桁桥温度效应分析

对某64m下承式半结合板桁桥建立有限元模型,并考虑其滑移和掀起效应。然后通过有限元模型对结构在温度荷载作用下的响应进行详细的分析,得出结论,有关经验可供类似工程参考。     

某越野车小偏置碰撞结构优化

针对25%小偏置碰工况,提出建立两道防线来应对,即前机舱设计的主动防线和乘员舱设计的被动防线,其中前机舱设计是应对小偏置碰的关键。利用建立的小偏置碰数学模型,推导出前机舱设计的两种思路:车体与壁障的重叠量最小、前机舱结构吸能最大,并且给出这两种思路的参考结构(shotgun环型结构)。利用这个设计思路对某非承载式车身越野车的前机舱和乘员舱进行设计优化,使小偏置碰性能的车体结构评价结果由POOR提升为GOOD,证明设计思路的有效性;同时,为了更好地利用承载式车身的结构特点,对承载式车身的汽车结构设计提出了建议。     

湖北襄荆高速公路天桥优化设计实践

湖北襄樊至荆州高速公路施工图设计中天桥共61座。在工程施工前,对其中的16座分别进行了优化布置,包括取消、改建移位、增加功能、修改桥型以协调景观等4种方案,最后共建设天桥52座。使高速公路与沿线道路交叉更加合理,也为项目节省了较大投资。     

日本船级社关于航行中船舶维修的指导书

为了保证船舶在船舶检验证书有效期内具有相应的技术标准,日本船级社(CLASS NK)特别制定了"航行中船舶维修"指导书.现简介如下,以供借鉴.     

基于Vega的虚拟海洋视景仿真研究

虚拟海洋视景仿真系统足虚拟现实技术在军事领域中的应用.由于海浪运动的随机性,虚拟海洋的计算机生成成为视景仿真领域的研究难点.文中详细讨论了两种海浪模型,重点研究Vega中海浪原理和海洋模块的计算机实现,基于Vega软件生成海浪.从效果图中可以看出,模拟的海浪效果比较好,能够满足实际应用的需求.