IS-95 CDMA前向同步信道仿真

分别对IS-95码分多址标准和SystemView软件进行了介绍,概述了IS-95前向同步信道的基本特点和性能参数,给出了采用SystemView软件仿真IS-95码分多址标准前向同步信道的方法和仿真结果。     

利用AOS插入业务实现伪码测距的实验验证

通过搭建桌面联试系统对利用高级在轨系统(AOS)插入业务实现伪码测距方案进行实验验证。实验系统包括星上插入和地面提取2个过程。用设计电路模拟测距环路，主要验证测距伪码在插入和提取过程中处理时延的稳定性。实验结果表明，时延的稳定性能够满足测距要求。由此说明插入法可用于伪码测距。     

短波信道多普勒扩展仿真与实现

针对直接FIR滤波和多级内插滤波生成衰落因子的算法中存在算法复杂度高、计算效率低、存储空间大等问题,文章研究了一种多级迭代滤波的算法,以降低算法复杂度和减少存储空间,实时生成衰落因子;并进行了算法的复杂度分析和仿真实现,验证了算法的有效性.     

E1784K基因变异与钠离子通道病建模与仿真(英文)

临床报道发现SCN5A上的一个位点突变E1784K基因变异会导致同时出现长QT间期III型综合征和Brugada综合征的特征。E1784K基因变异引起钠离子通道功能改变,但无法确定钠离子通道功能的改变是否能够解释LQT3和BrS交叠现象。为分析该问题,建立了详细的计算模型,从动作电位、有效不应期和伪心电图三方面进行仿真。仿真结果表明E1784K基因突变导致钠离子通道改变不能直接解释LQT3和BrS心电图特征交叠现象,而间接引起的ITo或者ICaL重构可以解释该现象。     

Relative position and attitude estimation of spacecrafts based on dual quaternion for rendezvous and docking

The capacity to acquire the relative position and attitude information between the chaser and the target satellites in real time is one of the necessary prerequisites for the successful implementation of autonomous rendezvous and docking. This paper addresses a vision based relative position and attitude estimation algorithm for the final phase of spacecraft rendezvous and docking. By assuming that the images of feature points on the target satellite lie within the convex regions, the estimation of the relative position and attitude is converted into solving a convex optimization problem in which the dual quaternion method is employed to represent the rotational and translational transformation between the chaser body frame and the target body frame. Due to the point-to-region correspondence instead of the point-to-point correspondence is used, the proposed estimation algorithm shows good performance in robustness which is verified through computer simulations.     

Numerical investigation on flow field characteristics of dual synthetic cold/hot jets using POD and DMD methods

In order to improve the control ability of synthetic jets in compressible boundary layer, a novel control method based on dual synthetic cold/hot jets coupled control of velocity profile and temperature profile was proposed. As fundamental investigations on the effects of synthetic jet temperature on the jet behavior and flow field characteristics were essentially necessary, preliminary numerical simulations were conducted to study the influence of temperature (200 K and 400 K) on the flow field characteristics of synthetic jets using Large Eddy Simulations (LES) model. Time-averaged flow fields showed that different temperatures led to variable behavior of two strands of jets. For dual synthetic cold jets, a potential-core arose apparently with its height ranging from 0.01 to 0.03 m, while for dual synthetic hot jets, two strands of jets emerged downstream. The modal decomposition of instantaneous flow fields had been done using both Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD). Various modes showed different characteristics of the flow fields. As the POD method focuses on the energy of flow while the DMD method focuses on the frequency, the first two modes had many similarities, but the third and fourth modes demonstrated completely different vortex structures. The current researches play a role of preliminary investigations for further and comprehensive exploration of novel flow control measures in global velocity field.     

复杂通道类零件五轴加工刀轴规划

针对复杂通道类零件的五轴数控加工,提出一种控制刀轴稳定变化的刀轴规划方法。首先,通过对刀轴可行空间的均匀离散,建立一种高效求解刀轴可行空间精细边界的方法;然后,依据刀轴矢量规划准则,求解满足机床角加速度约束的可行刀轴序列集合,并提出一种切削行内旋转坐标线性变化的刀轴矢量规划方法;最后,通过建立刀轴变化和残留高度综合评价指标,得到优化的刀轴矢量,并与典型的商用软件进行了实验对比验证。结果表明,使用本文提出的刀轴规划方法得到的切削行刀位轨迹旋转坐标变化均匀,旋转轴角加速度最大值降低到商用软件的10%以下,残留高度平均值降低了22%,改善了切削过程的稳定性,提高了加工表面质量。     

对企业战略执行系统有效运作的思考

企业在战略运行过程中,应首先建立有效的战略执行机制,否则企业战略难以执行.所以企业在执行战略时,应考虑战略执行系统的核心问题,主要有:制定战略是企业决策层工作的核心;建立与战略相适应的组织支持系统;建立战略性人力资源管理;建立执行文化;建立好的管理机制;建立有效的情报系统;建立有效的战略评估与跟踪机制.只有这样,才能逐步建立战略执行系统,才能保障企业的战略目标的实现.     

一种新Turbo码交织器的VHDL设计

介绍了Turbo码和交织技术，分析了几种常用交织算法的特点。根据组合交织器的设计思路，提出了隔行写入螺旋式交织方案。利用硬件描述语言（VHDL）编程设计了这种交织器的电路，并给出了仿真结果。     

供应链变迁与航空货运经营模式的转变

通过对供应链理论的演变过程、渠道理论及目前中国航空货运经营模式的分析,认为中国航空货运已经具备了采用多种经营模式的能力,并且应当进行经营模式的转变;在采用多种模式时,首先要处理好渠道冲突和合作问题。