Large-scale high performance computation on 3D explosion and shock problems

Explosion and shock often involve large deformation, interface treatment between multi-material, and strong discontinuity. The Eulerian method has advantages for solving these problems. In parallel computation of the Eulerian method, the physical quantities of the computaional cells do not change before the disturbance reaches to these cells. Computational efficiency is low when using fixed partition because of load imbalance. To solve this problem, a dynamic parallel method in which the computation domain expands with disturbance is used. The dynamic parallel program is designed based on the generally used message passing interface model. The numerical test of dynamic parallel program agrees well with that of the original parallel program, also agrees with the actual situation.     

基于非参数方法的频率密度分布计算及其并行优化

跳频序列预测是信息对抗的关键问题之一。基于跳频序列具有的伪随机特性和数据之间连续分布的相似性,采用非参数密度估计方法计算并预测出频率的大概率分布区间,进而用于引导通信的梳状灵巧干扰。针对实际应用对实时性的要求,在多结点多核平台上实现了基于消息传递机制的可扩展计算。测试表明,并行程序计算结果正确,并且具有较好的可扩展性。     

消息驱动思想在单片机定时体系中的应用

提出了用消息驱动思想来构造单片机控制系统中的定时体系，阐述了消息驱动思想的基本原理及其在单片机系统中的具体实现．该思想方便地解决了用较少资源实现复杂多变的定时要求的问题．     

Demonstration of a coupled floating offshore wind turbine analysis with high-fidelity methods

This paper presents results of numerical computations for floating off-shore wind turbines using, as an example, a machine of 10-MW rated power. The aerodynamic loads on the rotor are computed using the Helicopter Multi-Block flow solver developed at the University of Liverpool. The method solves the Navier–Stokes equations in integral form using the arbitrary Lagrangian–Eulerian formulation for time-dependent domains with moving boundaries. Hydrodynamic loads on the support platform are computed using the Smoothed Particle Hydrodynamics method, which is mesh-free and represents the water and floating structures by a set of discrete elements, referred to as particles. The motion of the floating offshore wind turbine is computed using a Multi-Body Dynamic Model of rigid bodies and frictionless joints. Mooring cables are modelled as a set of springs and dampers. All solvers were validated separately before coupling, and the results are presented in this paper. The importance of coupling is assessed and the loosely coupled algorithm used is described in detail alongside the obtained results.     

Web服务环境下基于信息协商的组合服务多属性选择方法

Web服务环境下,通过对QoS感知服务选择问题及信息协商流程的形式化描述分析,从信息协商的重复考虑用户需求特点出发,提出了基于信息协商的组合服务选择方法及具体实现途径。该方法能综合体现动态协商和犹豫度特点,并且有效避免了评价信息的丢失。最后,通过实例分析表明该方法对于Web服务环境下组合服务选择应用的可行性和有效性。     

Quantum Message Distribution

The semiquantum techniques have been explored recently to bridge the classical communications and the quantum communications.In this paper,we present one scheme to distribute the messages from one quantum participate to one weak quantum participate who can only measure the quantum states.It is proved to be robust by combining the classical coding encryption,quantum coding and other quantum techniques.     

基于改进的BP网络对CET-4累计通过率时间序列的预测

时间序列并非总呈自相关性.与[4]不同,对本文中的CET-4累计通过率时间序列建立线性及二阶自回归模型,仿真计算失效.改进的BP网络,适用所有的一维时间序列.本文采用二步预测法,与其它采用BP网络对时间序列预测不同的是,本文不仅预测下一年的时间序列值,还将整个预测模型仿真出来,画出三维图形,从而为教务政策的制订提供直观易看、合理、客观的依据.     

重力式码头CAD集成系统的面向对象实现

本文所构建的重力式码头CAD集成系统GrawCAD(Gravity Wharf CAD Integrated System)将面向对象的编程方法贯穿于系统各个模块的具体实现过程中，集分析、设计与绘制工程图于一体，具体集成的模块包括：数据输入、构件设计、结构分析与优化设计、工程图纸的绘制和工程文档的编制等。GrawCAD利用标准的C 实现了适用于Windows及Linux等不同操作系统的核心计算类库，采用AutoCAD二次开发技术开发了工程图纸绘制模块，利用内存数据映射在系统不同进程间传递数据，利用消息发送及多线程对数据实时更新。     

On the properties of elastic-viscous fluid flow past an obstacle

Fundamental equations for the analysis of plane flow of elastic-viscous fluid are established.On such a basis,a perturbed-weighted residual finite element model for small Deborah number situations is formulated.The model is further incorporated for investigations on the behavioral characteristics of the elastic-viscous fluid flow when passing an obstacle,which include the mechanisms of the retardation of separation point,and the reduction of drag forces and so forth.The numerical investigations demonstrate the favorable advantages of the present model in its remarkable simplicity and reasonable accuracy attained in plane flow analysis.