并行程序调试中的环境再现技术

为解决调试并行程序碰到的第一个困难:并行程序的不确定性,文中提出了环境再现技术。文中叙述了环境再现技术的思想和实现这一技术需要的数据结构,并用CCNPASCAL语言进行了描述,最后给出了一个典型的应用例子。     

一种新的批处理常模算法

详细分析了传统批处理常模算法的缺点,提出了一种新的批处理常数模算法——基于共轭梯度方向的批处理常模算法(CG-BPCMA).仿真结果表明,与最陡下降批处理常模算法(SD-BPCMA)和牛顿方向批处理常模算法(NT-BPCMA)相比,提出的新算法有效地克服了SD-BPCMA和NT-BPCMA的缺点,不仅获得了较低的算法复杂度,而且能快速收敛到常模代价函数的最小值点.     

抗差最小二乘估计在惯组外场标定中的应用

惯组在外场进行标定时常常会受到环境的振动干扰,从而会对惯组的标定精度造成极大的影响.为解决这一问题,在分析了粗差对惯组标定精度影响的前提下,建立了一种改进的辨识惯组误差系数的数学模型,使其能够分辨出那些受到振动干扰影响的惯组误差系数.最后利用抗差最小二乘估计对惯组误差系数进行处理,通过等价权函数的连续降权和连续减弱影响处理,抵制了异常数据对惯组标定精度的影响.仿真结果表明,抗差最小二乘估计具有很强的抗差能力,能有效减弱异常干扰对参数估计的影响,提高惯组外场标定的精度和数据的可靠性.     

A queueing system with vacations after N services

This article is devoted to the study of an M/G/1 queue with a particular vacation discipline. The server is due to take a vacation as soon as it has served exactly N customers since the end of the previous vacation. N may be either a constant or a random variable. If the system becomes empty before the server has served N customers, then it stays idle until the next customer arrival. Such a vacation discipline arises, for example, in production systems and in order picking in warehouses. We determine the joint transform of the length of a visit period and the number of customers in the system at the end of that period. We also derive the generating function of the number of customers at a random instant, and the Laplace–Stieltjes transform of the delay of a customer. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 646–658, 2015     

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established. According to the relation of the dynamic seven photoelectric detection screen planes and the time values, the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.     

一种基于GPU的数字信道化处理方法

为了减少数字信道化接收机的开发成本,提高吞吐量与处理速度,对被动雷达截获信号数字信道化接收机的结构进行了研究,提出了一种基于GPU的数字信道化接收机的实现方法。该高效结构不仅节省了硬件成本,缩短了开发周期,而且加快了处理速度,达到了准实时性。实验结果表明:基于GPU的运算平台与CPU平台相比较,处理速度提高一倍左右。     

捷联惯导在线标定的时间延迟补偿方法影响分析

在捷联惯导在线标定过程中,由于主惯导的解算和传输延迟,子惯导解算信息与进行匹配的基准信息不能完全同步,有些情况下时间延迟较大,且对标定精度的影响很大。首先介绍了一种消除时间延迟的方法,而后重点仿真研究了该方法中同步误差△t对捷联惯导在线标定精度的影响,仿真结果表明忽略会△t导致个别参数轻微发散,故为了进一步提高标定精度,在标定过程中考虑同步误差△t是必要的。     

网络分布式分级数据处理技术

针对现代战争中多平台多传感器协同作战的特点,提出了一种网络分布式分级数据处理技术。首先,通过网络分布式技术提升了整个作战系统的抗毁性,实现了指控作战的无缝交接。其次,通过分级融合技术解决了传统单级融合模式中由于数据回吐而造成的信息冗余问题,同时也降低了网络负载;最后,通过理论分析和仿真实验验证了分布式分级处理技术的可行性和有效性,具有较强的工程应用价值。     

均匀面积映射及其在均匀纹理映射中的应用

为形成一个具有更小拉伸的网格参数化映射,在三角形网格面片面积均匀分布的情况下,采用分两步走的均匀面积映射法。通过均质化参数域里的三角形面积,用均匀或不均匀方式有效地降低了采样稀疏问题的影响,避免了传统方法中矩阵奇异值的计算。对三角形网格,先进行均值协调参数化,然后通过一个凸组合让参数域更加均匀,得到一个拉伸较低、面积更加均匀的三角形分布,从而可以更好地取样且适合于纹理映射。通过实验和对比,可以证明在均匀纹理映射方面,均匀面积映射法比保角映射法和等积投影映射法都有明显的提高。     

具有分布时滞的随机反应扩散细胞神经网络的几乎必然指数稳定性

研究一类具有分布时滞和反应扩散的随机细胞神经网络的稳定性。通过构造Lyapunov泛函,并利用It公式、半鞅收敛定理以及不等式技巧,得到了系统几乎必然指数稳定的充分条件。