水平极化电磁脉冲模拟器空间场的数值模拟

 采用时域有限差分方法，对水平极化电磁脉冲模拟器所产生的电磁场进行数值模拟，在时域中计算了电磁场的时间 空间分布。讨论了电磁脉冲模拟器产生的电磁脉冲波形和场的空间变化、均匀性等重要因素。结果表明，模拟器产生的电磁脉冲前沿为10ns，接近脉冲电压前沿，波形与脉冲电压波形（双指数波）相差较大；峰值场强在对称轴上并非与距离成反比，而是随距离增大而迅速减弱；该模拟器的双锥 笼形天线能在大范围内（大于等于50m,水平方向）产生均匀分布、高峰值场强、快前沿的电磁脉冲。     

Adaptive multimedia streaming using a simulation test bed

The major purpose of this paper is to transmit an existing video above a complete simulated video streaming architecture based on Network Simulator (NS2). Thanks to our architecture, the visual quality evaluation of the distributed streaming platform under various conditions is simplified. Indeed, the received video can be easily visualized using a classic video client or be compared using the Peak Signal-Noise Ratio (PSNR) value and the Structural SIMilarity (SSIM) value. In the case study, we compare adaptive video congestion strategies using a transcoder, Datagram Congestion Control Protocol (DCCP) and TCP-Friendly Rate Control (TFRC).     

高功率粒子束及其应用

本文评价了高功率粒子束的工作原理及其应用:文中以闪光-Ⅰ强流脉冲电子束加速器为例,论述了机器的基本技术和它的工作特性 高功率粒子束目前已经应用到许多重要研究领域。包括:核辐射效应模拟源、闪光X射线照相、高功率激光器研究、惯性约束聚变、高功率微波的产生、离子集体加速等方面。 报告中简述了我国在高功率粒子束加速器建造和开拓应用方面取得的进展。 最后,也指出了高功率粒子束技术今后发展有关的研究课题。     

基于PXI总线的小卫星扩频应答机模拟器的设计与实现

应用PXI总线、扩频通信、软件无线电等技术,设计并开发了一种小卫星扩频应答机模拟器,可作为真实应答机的替代产品参与卫星初样产品桌面联试、与地面站对接等试验.同时基于PXI总线的灵活架构以及模块化设计思路,可实现快速升级,为新算法提供通用验证平台。采用成熟的地面测试设备以及星上产品与该系统进行联试,验证了该应答机模拟器调制、解调等信号处理功能的正确性和有效性。     

某型火控雷达维修训练模拟器设计与应用

为了提高教学效果,减少实装损耗,加强新装备保障能力,研制某型火控雷达维修训练模拟器;该模拟器以网络化主控计算机单元为核心,由实装操作分系统、虚拟装备分系统、实装部组件分系统、动感分系统、联动分系统组成,具有操作训练、维修训练、武器系统联动训练及训练评估等功能,解决了新型雷达装备教学与训练中实装损耗大、装备数量少、训练效率低等问题;该模拟器已用于多个雷达专业的操作、维修、综合演练等教学实践中,与以往的训练设备相比可操作性好,应用范围广,教学效果明显;文中介绍了模拟器的功能结构、硬件设计、软件设计及其应用。     

基于幅频自校准的高精度LVDT模拟器设计

LVDT模拟器在航空发动机的测试系统中有着广泛的应用,针对传统模拟器中由于引入变压器导致精度低的缺点,从LVDT传感器原理出发,设计了一种幅频自校准方法,利用乘法型DAC芯片实现了电路合成模拟LVDT传感器的目的并克服了变压器的幅频响应,提高了LVDT模拟器在宽频率范围的仿真精度。该模拟器已成功应用于某型号发动控制系统的地面仿真测试系统中,达到了预期效果。     

基于软件接收机的卫星导航信号模拟器性能指标测试

针对卫星导航信号模拟器的性能指标测试评估问题,提出了基于软件接收机的性能指标测试方法;通过分析模拟器性能,包括对动态性能、相位噪声、通道间时延一致性和静态定位精度的综合分析,给出了相应的测试方法和测试流程,并结合卫星导航信号模拟器产生的实际信号对各项性能指标的测试结果进行分析;经测试结果表明,软件接收机可以有效地对卫星导航信号模拟器各项性能指标进行测试,测试结果符合理论预期,满足模拟器性能指标测试评估的需求。     

红外多干扰目标模拟器电控系统的实现

红外多干扰目标模拟器提供了一个虚拟的仿真环境,通过模拟红外目标及其释放的干扰的运动情况对红外制导导弹的性能进行测试.在其电控系统的设计中,采用双口RAM来进行多机通讯,并采用了多种控制方法,使系统各性能需求得以较好地实现。     

Quasi-optical analysis of a far-infrared spatio-spectral space interferometer concept

FISICA (Far-Infrared Space Interferometer Critical Assessment) was a three year study of a far-infrared spatio-spectral double-Fourier interferometer concept. One of the aims of the FISICA study was to set-out a baseline optical design for such a system, and to use a model of the system to simulate realistic telescope beams for use with an end-to-end instrument simulator. This paper describes a two-telescope (and hub) baseline optical design that fulfils the requirements of the FISICA science case, while minimising the optical mass of the system. A number of different modelling techniques were required for the analysis: fast approximate simulation tools such as ray tracing and Gaussian beam methods were employed for initial analysis, with GRASP physical optics used for higher accuracy in the final analysis. Results are shown for the predicted far-field patterns of the telescope primary mirrors under illumination by smooth walled rectangular feed horns. Far-field patterns for both on-axis and off-axis detectors are presented and discussed.     

Quantitative evaluation of optimal imaging parameters for single-cell detection in MRI using simulation

Super-paramagnetic iron oxide (SPIO) nanoparticles are actively investigated to enhance disease detection through molecular imaging using magnetic resonance imaging (MRI). Detection of the cells labeled by SPIO depends on the MRI protocols and pulse sequence parameters that can be optimized. To evaluate the sensitivity and specificity of the image acquisition methods and to obtain optimal imaging parameters for single-cell detection, we further developed an MRI simulator. The simulator models an object (tissue) at a microscopic level to evaluate effects of spatial distribution and concentration of nanoparticles on the resulting image. In this study, the simulator was used to evaluate and compare imaging of the labeled cells by the gradient-echo (GE), true-FISP [fast imaging employing steady-state acquisition (FIESTA)] and echo-planar imaging (EPI) pulse sequences. Effects of the imaging and object parameters, such as field strength, imaging protocol and pulse sequence parameters, imaging resolution, cell iron load, position of SPIO within the voxel and cell division within the voxel, were investigated in the work. The results suggest that true-FISP has the highest sensitivity for single-cell detection by MRI.