光电侦察平台电磁屏蔽设计

为了使光电侦察平台满足现代战场复杂的电磁环境要求,对某型光电侦察平台进行了电磁屏蔽设计。电磁屏蔽技术是抑制辐射干扰、提高系统电磁兼容性的最有效手段之一。分析了光电侦察平台在进行电磁屏蔽时的技术难点,根据其特有的技术难点,提出了一些实际可行的解决措施。对改进后的光电侦察平台进行了电场辐射发射（RE102）试验测试。测试结果表明经过合理的电磁屏蔽处理,可使光电侦察平台电场辐射发射值降低约10 dBV/m,提高了光电侦察平台的电磁兼容性。综合采取屏蔽、接地及滤波等技术手段,可使光电侦察平台的电磁兼容性满足GJB151A-1997中的规定。     

用串接电光偏转器提高时空变换装置进行激光脉冲整形的能力

介绍了在时空变换装置中用两个电光偏转器串接和并接的工作原理 ,从理论上分析了用其提高激光脉冲整形的能力 ,进行了激光脉冲削波实验 ,实验结果与理论分析一致。用两个偏转器串接后 ,大大提高产生整形激光脉冲的能力     

运动平台光电跟踪瞄准技术研究

提出了一种运动平台光电跟踪瞄准方案．该方案采用光电跟踪技术对机动目标进行跟踪滤波,给出了一种数字式闭环跟踪滤波设计方法．利用闭环滤波估计出目标运动参量并预测出目标未来时刻的位置。     

激光对光电成像制导的图像干扰效果评估

分析了光电成像制导武器跟踪原理和激光对光电成像制导武器干扰机理,提出了一种激光对光电成像制导武器图像干扰效果的评估系统,系统结构简单,易于实现,可用于评价光电对抗装备对光电成像制导武器的干扰效能.     

紧凑型炮塔角位移传感器的总体设计

介绍了ADT - 88B 炮塔角位移传感器机械结构设计方案,讨论了组合绝对式光电轴角编码器,以及数据处理硬件和软件方面的设计,试验和使用结果表明设计满足指标要求。     

Transflective In-Plane Switching Liquid Crystal Display

A single cell gap, single gamma curve, and low operating voltage transflective liquid crystal display (LCD) using an in-plane switching (IPS) cell is proposed. In the IPS cell, the pixilated transparent indium tin oxide electrodes are on the top substrate and the reflectors are on the bottom substrate. The electro-optic properties of the transflective IPS LCD are calculated using three-dimensional simulation software. By optimizing the reflector width, the voltage-dependent transmittance and reflectance curves can be matched     

IDS与IPS将长期共存

入侵检测系统和入侵防御系统都有其特定的优势和市场,近年来有关IPS和IDS的发展有过非常多的研究和探讨。论文首先对IPS、IDS功能特性和发展历程进行了总结,然后对IPS仍需完善的地方和IDS不可替代的特性进行整理归纳,最后就入侵检测防御机制未来的发展方向进行了探讨。     

In-Plane Switching Technology for Liquid Crystal Display Television

In-plane switching (IPS) technology used for liquid crystal display (LCD) TV is reviewed. Requirements of HD TV application are listed, and the main performances are compared among various competing display technologies. IPS LCD mode shows superior performances, satisfying the requirement for HD TV application.     

Multivalent Polyanionic 2D Nanosheets Functionalized Nanofibrous Stem Cell-based Neural Scaffolds

Because developed neural cells are no longer regenerative and proliferative, achieving neural regenerations by using induced pluripotent stem cells (IPS cells) for nerve diseases have recently attracted much attention. Since the IPS cells’ growth and differentiation can be manipulated by different physical and chemicals cues, scaffolds combining the beneficial nanostructures and extracellular matrix may become an ideal interface to promote IPS cells’ neural differentiation. In this work, a biocompatible and multivalent polyanion, hyperbranched polyglycerol sulfate, is used to modify the graphene oxide to obtain bio-adhesive 2D nanosheets. After coating electrospinning nanofibers, the 2D nanosheets-functionalized nanofibrous scaffolds are applied to mediate the proliferation, lineage specification, and neural differentiation of IPS cells. The results suggest that the modified scaffolds can improve the adhesion and proliferation of IPS cells combined with high efficiency in maintaining their stemness. During the neural differentiation process, the scaffolds can promote neural differentiation and their maturity, meanwhile decreasing the lineage specification toward astrocyte. Overall, this study not only provides new multivalent/bio-adhesive nanofibrous scaffolds that integrate the chemical and physical cues to facilitate the targeted neural differentiation of IPS cells but also presents a novel pathway for the fabrication of carbon nanomaterials-based biocomposites in regenerative therapies.     

人工智能赋能的多功能光子处理系统北大核心

智能光子处理系统(IPS)融合了人工智能(AI)技术和光子技术,旨在实现智能、高速、大带宽、高性能的信号处理。IPS主要包括人工智能赋能的多功能光子处理系统、光子辅助的人工智能信号处理系统和基于神经拟态的光子处理系统。文章首先简要介绍了IPS的概念内涵,然后重点介绍作者所在课题组在人工智能赋能的多功能光子处理系统方面的研究进展,再进一步探讨人工智能赋能研究从不可解释逐渐走向可解释的发展趋势和必要性,接着介绍该课题组已开展的具有一定可解释性的人工智能赋能的光子处理系统研究,最后对全文进行总结。     

基于菱形电极结构的高对比度平面内扭转模式蓝相液晶显示器件设计

以往研究发现平面内扭转(In-Plane Switching,IPS)模式蓝相液晶显示器件的图像显示对比度明显低于理论预期。本文对导致这一问题的物理原理进行理论分析和实验验证,据此提出改进的菱形电极结构设计以解决这一问题。实验证明,调整走向后的IPS电极结构能使蓝相液晶显示器件的暗态漏光减小2/3,使其显示对比度提升至10 000∶1以上。基于这一实验发现,本文提出了全新的菱形电极结构设计,以求获得高对比度显示效果。除此以外,采用Techwiz仿真分析改进后的菱形IPS电极蓝相液晶显示器件的电光特性,发现其伽玛偏移和灰度反转可分别减小3/4和2/3,并且其驱动电压和透过率与传统IPS模式蓝相液晶显示器件相仿。可见,基于改进的菱形IPS电极结构的蓝相液晶显示器件相较传统蓝相液晶显示器件具备更好的显示性能和市场竞争力。     

基于T-S模糊模型的倒立摆

用牛顿力学方法建立了直线一级倒立摆的非线性数学模型,并基于倒立摆系统的状态方程,用Matlab对系统进行定性分析。采用极点配置法、LQR设计了控制器,并分析了参数对系统控制的影响。针对倒立摆的非线性,研究了非线性控制方法中变结构控制的基本思想,并设计了控制器。     

Dynamic Bandwidth Allocation Algorithms for Ethernet Passive Optical Networks with Threshold Reporting

In this paper we present a dynamic bandwidth allocation algorithm for Ethernet Passive Optical Networks (EPON), which makes use of the Multipoint Control Protocol (MPCP) with threshold reporting and with inter- and intra-ONU priority scheduling. Three varieties of this algorithm are compared under both symmetric and asymmetric traffic conditions, by means of a detailed simulation program, regarding average packet delay for several priorities, delay variation for constant bit rate (CBR) traffic and bandwidth utilization. Two types of intra-ONU priority scheduling algorithms are considered, being full and interval priority scheduling, called FPS and IPS, respectively. It is shown that by combining IPS with the threshold reporting mechanism one can achieve a nearly optimal bandwidth utilization (by avoiding nearly all fragmentation losses). IPS, however, causes an increased packet delay and delay variation for CBR traffic in comparison with FPS. In order to eliminate this drawback, we combine the IPS scheduling algorithm with a rate-based scheme for the highest priority (CBR) traffic. The combined IPSA algorithm provides an interesting trade-off between the efficiency, which is still near to the optimal, and the delay characteristics of time critical applications. Finally, we also demonstrate that unfairness arises with FPS under asymmetric traffic conditions, that is, ONUs with more best effort traffic are favored by FPS. Whereas asymmetric traffic conditions only slightly affect the fairness of IPS under low load conditions.     

连续单频激光的腔外调频及其在光谱测量中的应用

研制了一台通光孔径为２ｍｍ的ＬｉＴａＯ３射频电光调制器，调制频率为９５ＭＨｚ。获得十个边频分量，并对调频结果作了分析。应用此器件所产生的调频激光束测得２３８Ｕ和Ｌａ的荧光谱，对比和分析了单频激光和调频激光荧光谱的差别，获得了明显的谱线增宽及增强效应。     

入侵防御系统技术

随着网络入侵事件的不断增加和黑客攻击水平的不断提高,网络安全越来越受到人们的重视。入侵防御系统作为一种新的网络安全技术,具有一般普通防火墙和入侵检测所不具有的优越性能。文章重点介绍了入侵防御系统的基本工作原理、技术特点及种类,并介绍了入侵防御系统IPS面临的4个主要问题及其以后的2个发展方向。     

基于DSP与FPGA的嵌入式伺服控制系统的研究

介绍了一种基于PXI总线、以DSP和FPGA为核心处理器的嵌入式光电跟踪伺服系统,并给出了系统硬件、DSP控制软件的设计及DSP程序在线加载的方法．     

Intelligent prognostics system design and implementation

This paper proposes an intelligent prognostics system JPS) for semiconductor and TFT-LCD manufacturing. The IPS comprises several generic embedded devices (GEDs) and remote clients. The GED can be easily embedded into various types of equipment to acquire equipment engineering data and meet the specification requirements of Interface A for supporting semiconductor industry equipment engineering capabilities. Furthermore, the GED has an open-standard application interface offering pluggable and customized intelligent applications. With this feature, the intelligent applications can be distributed and localized, releasing the factory network burden and enhancing equipment reliability and processing quality. This paper also develops two typical pluggable applications: the predictive maintenance scheme (PMS) for detecting equipment faults and the virtual metrology scheme (VMS) for conjecturing equipment-processing quality. Integrating the PMS into the IPS and the VMS into the IPS are, respectively, accomplished using the conveyor equipment and the sputtering equipment in a TFT-LCD factory. These two illustrative examples clearly demonstrate that IPS is versatile, configurable, and effective.     

光电图像动态检测系统应用

光电图像检测技术是以现代光学为基础,融光电子学、计算机图形／图像学、信息处理、计算机视觉等科学技术为一体的现代测量技术,介绍了光电图像检测系统原理及功能,并结合事例采用光电图像检测技术,对轨道的不平顺进行检测,获得其不平顺参数,给铁路的安全运行提供可靠的信息依据．     

液晶显示器件的特殊电光特性分析

对液晶施加电场,液晶分子的排列会发生转变,其光学性质也会相应发生变化.本文采用多功能光栅光谱仪测试了不同电压下液晶显示器件透射率随波长的变化关系,采用光学多道分析器测试了液晶显示器件透射能量随波长的变化关系,对液晶显示器件的特殊电光特性进行了深入研究分析,发现紫外、可见光、红外波段其变化规律是不同的.     

A Simplified Equalization Method for Dual PN-Sequence Padding TDS-OFDM Systems

Time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) modulation scheme can improve the spectrum efficiency over the traditional Cyclic Prefix (CP) OFDM technology at the cost of computational efforts due to the iterative padding subtraction (IPS) at the receiver to mitigate the inter symbol interference caused by the multipath propagation. In this paper, a simplified equalization scheme is presented for the dual PN-sequence padding (DPNP) TDS-OFDM systems. Although the length of the padded PN sequence needed is double compared to what needed by the IPS, leading to slight decrease of the spectrum efficiency, this method can save about 90% computational effort in practice compared with that of the IPS algorithm. It also outperforms IPS method under the time-varying fading channel in terms of symbol error rate and maximum Doppler frequency, verified by the computer simulation.