军事基础课程体系改革与研究

以新时期军事斗争准备为牵引,改革与创新军事基础课程体系,是我院"4+1"模式新型军事人才对军事基础教学与训练的客观要求.通过重点阐述我院围绕加强学员的素质教育,深化军事基础课程体系改革与研究的思路,为新形势下军事基础课程体系深层次的改革与发展,提供了若干参考.     

可压缩流动压力修正方程分析

依据Ｐａｔａｎｋａｒ提出的差分方程稳定性判断的４项基本法则,对可压缩流动的压力修正方程进行了分析,得出压力修正方程系数为正的条件．指出在每一次求解压力修正方程时必须提高解的收敛程度,以保证下一次迭代的差分方程矩阵接近主对角占优．分析了速度离散方程的欠松驰因子对可压缩流压力修正方程的影响．     

基于一种模型的中子星结构

从物态方程出发,利用中子星结构方程计算了中子星的结构。得到了引力质量材M_G=1.27M_θ材,转动惯量I=1.29x10(45)g/cm~2,与观测结果符合较好。     

飞船再入舱三维化学非平衡流数值模拟

对飞船再入舱高超声速化学非平衡三维流场进行数值模拟。控制方程为含化学反应源项的全Ｎａｖｉｅｒ－ Ｓｔｏｋｅｓ 方程组, 化学模型为高温空气的七组元模型, 其组元成分为Ｎ２ 、Ｏ２、ＮＯ、Ｎ、Ｏ、ＮＯ＋ 、ｅ－ 。差分格式采用张涵信院士提出的ＮＮＤ激波捕捉格式并用全耦合方法处理流动方程及化学反应方程, 对化学反应源项采用全隐式处理, 运用时间预处理技术以加快收敛。同时, 也对完全气体模型进行计算, 以分析真实气体效应。与实验数据对比, 说明本文结果是可信的。     

用于无线ATM的协议及方法分析

ＷＡＴＭ 被认为是下一代个人通信网络的解决方案,或是Ｂ－ＩＳＤＮ 网络的无线延伸。目前无线ＡＴＭ 仍处于发展初期,ＡＴＭ 论坛和ＩＴＵ－Ｔ 都未制定正式标准,研究人员正在建立实验性的Ｗ ＡＴＭ 网络,并在其上面实验各种不同的协议。ＡＴＭ 类的无线网络将在未来的宽带通信网中扮演一个重要的角色     

含非线性半群的微分包含

研究了形如X＇（t）∈-Ax（t）＋F（t,x（t））,0≤t≤T,X（0）＝x0的微分包含解的存在的局部性和整体性的结果,并在某种条件下研究了解的稳定性。     

长短周期记忆网络微调的氧气浓缩器寿命预测模型迁移

针对寿命预测模型迁移问题,提出了一种长短周期记忆网络微调(long short-term memory fine tune, LSTM-fine-tune)的迁移模型,利用理想条件下的试验数据对模型进行训练。在迁移过程中,对部分LSTM网络层进行冻结,利用实际服役环境下的数据对网络其他部分进行修正。为验证模型的泛化能力,采用不同相位与幅值的正弦函数生成数据,通过学习数据获取正弦函数的经验知识,并应用至其他正弦函数的回归,结果表明LSTM-fine-tune模型能够快速拟合,平均均方误差仅为1.033 5,明显低于直接预测误差1.536 8。为通过实际监测数据检验本方法泛化能力,分别获取了试验条件下与实际服役环境下氧气浓缩器的数据,对模型的泛化能力进行验证。结果表明,迁移后训练集预测精度提高了43.0%,测试集预测精度提高了20.2%。     

材料色散对全固态带隙光纤带内色散的影响

全固态光子带隙光纤已开始用于产生超连续谱,其带隙效应可以控制超连续谱的范围,但是带内的色散特性对于超连续谱的产生有着重要的影响.采用平面波法计算了同一带隙光纤不同阶带隙内的色散曲线和不同带隙光纤同阶带隙内的色散曲线,零色散波长在带内相对位置与带隙位置密切相关,在长波长区域,零色散点位于带隙的短波边;在短波区域,零色散点...     

Coherent systems based on sequential order statistics

The sequential order statistics (SOS) are a good way to model the lifetimes of the components in a system when the failure of a component at time t affects the performance of the working components at this age t. In this article, we study properties of the lifetimes of the coherent systems obtained using SOS. Specifically, we obtain a mixture representation based on the signature of the system. This representation is used to obtain stochastic comparisons. To get these comparisons, we obtain some ordering properties for the SOS, which in this context represent the lifetimes of k‐out‐of‐n systems. In particular, we show that they are not necessarily hazard rate ordered. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

Periodic review inventory management with contingent use of two freight modes with fixed costs

We study a stochastic inventory model of a firm that periodically orders a product from a make‐to‐order manufacturer. Orders can be shipped by a combination of two freight modes that differ in lead‐times and costs, although orders are not allowed to cross. Placing an order as well as each use of each freight mode has a fixed and a quantity proportional cost. The decision of how to allocate units between the two freight modes utilizes information about demand during the completion of manufacturing. We derive the optimal freight mode allocation policy, and show that the optimal policy for placing orders is not an (s,S) policy in general. We provide tight bounds for the optimal policy that can be calculated by solving single period problems. Our analysis enables insights into the structure of the optimal policy specifying the conditions under which it simplifies to an (s,S) policy. We characterize the best (s,S) policy for our model, and through extensive numerical investigation show that its performance is comparable with the optimal policy in most cases. Our numerical study also sheds light on the benefits of the dual freight model over the single freight models. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011