基金最佳使用计划

本文给出了基金存款策略的数学模型.对于基金M使用n年的情况而言,首先把M分成n份,其中第i(1≤i≤n)份存款xi存期为i年,那么只有当第i(i ≤n-1)份资金按最佳存款策略存款到期后的本息和等于当年的奖学金数,并且第n份资金按最佳存款策略存款n年后的本息和等于原基金M与当年的奖学金数之和时,每年发放的奖学金才能达到最多.通过求解此模型,我们得到了基金的最佳存款策略,并求出了在n=10年,M=5000万元的情况下,基金的最佳使用方案.在可存款也可购买国库券时,采取一种转化方法,将国库券购买情况转化为相应年期的定期存款,结合问题(一)即可求得在n=10年,M=5000万元的情况下,基金的最佳使用方案;在第三年校庆时奖学金数额比其它年度多20%的问题的分析方法和模型的解决方法与前相同.     

Preliminary Study in Spatial Data Warehouse of Flood Control and Disaster Mitigation in Yangtze River Basin

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桥梁病害桩基的加固处理

通过对铁路桥梁钻孔灌注桩病害事故的分析 ,探讨在保证列车安全运营条件下的临时加固措施 ,并提出了对此问题的一些看法     

A stability classification method and its application to pipelined solution of linear recurrences

A new method of classification for numerical stability of parallel algorithms is proposed based on the theoretical foundation of forward error analysis. It partitions the algorithms according to their asymptotic stability—a measure introduced to relate the limiting behavior of the stability to the size of the problem. Using this method, the stability aspect of the pipelined solution technique for first-order and second-order linear recurrences—the core of a tridiagonal linear equation solver—is studied. In particular, it shows that the pipelined solution method of the first-order linear recurrences has the same degree of stability as the commonly used sequential evaluation algorithms. The stability problems of sequential and pipelined solution methods of the second-order linear recurrences are also studied.     

火箭燃气射流对斜板冲击流场的数值模拟

采用高精度，高分辨率的二阶ＴＶＤ有限体积方法，对二维无粘射流冲击斜板的复杂流动场进行了数值模拟，得到了和实验规律相一致的计算结果。     

一种云存储系统数据持久存储机制

针对云存储中的可靠性产生的担忧,提出一种云存储系统完善的数据存储保障机制,以保证系统的高可靠性和数据的高可用性。在处理与数据持久存储的相关的数据分片、数据分发、完整性检查以及冗余数据的维护中,引入基于纠删码的数据冗余机制,与传统的复制冗余方案相比,能够在获得相同的数据可用性时降低存储空间和网络带宽的开销多达50%以上。采用基于缓冲区的分段读入编码对纠删码算法进行优化后,提高了对文件分片与合并的平均编码速率。     

Development of a simple model for batch and boundary information updation for a similar ship’s block model

In early 2000,large domestic shipyards introduced shipbuilding 3D computer-aided design (CAD) to the hull production design process to define manufacturing and assembly information.The production design process accounts for most of the man-hours (M/H) of the entire design process and is closely connected to yard production because designs must take into account the production schedule of the shipyard,the current state of the dock needed to mount the ship’s block,and supply information.Therefore,many shipyards are investigating the complete automation of the production design process to reduce the M/H for designers.However,these problems are still currently unresolved,and a clear direction is needed for research on the automatic design base of manufacturing rules,batches reflecting changed building specifications,batch updates of boundary information for hull members,and management of the hull model change history to automate the production design process.In this study,a process was developed to aid production design engineers in designing a new ship’s hull block model from that of a similar ship previously built,based on AVEVA Marine.An automation system that uses the similar ship’s hull block model is proposed to reduce M/H and human errors by the production design engineer.First,scheme files holding important information were constructed in a database to automatically update hull block model modifications.Second,for batch updates,the database’s table,including building specifications and the referential integrity of a relational database were compared.In particular,this study focused on reflecting the frequent modification of building specifications and regeneration of boundary information of the adjacent panel due to changes in a specific panel.Third,the rollback function is proposed in which the database (DB) is used to return to the previously designed panels.     

跳数加权DV-Hop定位算法

针对DV-Hop定位算法中距离估计误差对定位结果的影响,提出了一种信标节点优选方案和跳数加权DV-Hop定位算法。首先通过设定跳数阈值,保留跳数较少的信标节点,然后剔除近似在一条直线上的信标节点,完成信标节点优选,避免未知节点无法定位的情形。此外,利用Friis模型推导出距离估计误差与信号传播跳数之间的映射关系,采用传播跳数作为加权因子对定位结果进行了修正。仿真结果表明该算法降低了距离估计误差对定位精度的影响,提高了定位精度。     

膨胀弯管在管道柔性设计中的定性分析

为防止管道因热胀冷缩、管道支撑或端点附加位移造成的应力问题,对管线中设置的膨胀弯管进行定性分析.通过2个参数的变化对膨胀弯管进行编号得到多种设计方案,用ANSYS建立管道的有限元模型,并分析各方案中膨胀管道的变形、应力和弯矩等;根据分析结果对膨胀弯管设计半径、设置位置和形状进行定性分析.该定性分析结果可为膨胀弯管概念设计和管道柔性设计提供参考.