基于树莓派的视频矩阵控制服务器设计

本文设计了一种基于MAX-1000视频矩阵系统和嵌入式Linux系统的视频矩阵控制服务器.采用树莓派作为控制器,通过RS-232串口接收键盘的切换和云台控制指令,解析该指令并转换成视频矩阵指令,再通过RS-232串口将指令下发给视频矩阵,实现对矩阵的切换和云台的控制.同时,设计了一个WEB服务器,可在WEB页面上配置视频矩阵控制服务器的参数,实现了视频矩阵的远程切换和云台PTZ控制.该控制服务器具有使用方便、功能强大、可扩展、易维护、可靠性高等特点,已成功应用到现场,能够满足大型监控现场的监控需求.     

基于树莓派的系统的设计与实现

当今网络视频监控的使用率越来越高,而家庭安全的视频监控还未得到人们的重视,因此设计一个家庭的网络视频监控是有必要的.本文采用树莓派作为平台、选用开源的Mjpg-Streamer,运用HTML语言编辑网页,并结合CSS美化网页、用JavaScript开发脚本,连接USB摄像头,开发了一个实时查看视频和静态图像的视频监控系统,该系统能够保存并查看历史图像.     

基于Android和Raspberry Pi的远距离视频监控系统的设计

为了实现视频监控的移动性和远程操控,结合无线网络、Java语言和Eclipse开发编译工具,提出一种使用Android和Raspberry Pi组合,实现远程实时视频监控的新思路。摄像头获取图像数据,通过Raspberry Pi处理后以视频流的形式上传到图像服务器,以Android智能手机作为移动控制终端,通过Wi Fi访问图像服务器,获取图像数据并在控制界面进行显示,用户通过视频信息对移动机器人进行远程控制,达到远程实时监控的效果。通过实验测试,该系统可以有效地进行远程视频监控,具有良好的可用性。     

基于树莓派的室内烟雾检测系统的设计与实现

文章介绍了Linux操作系统环境下基于树莓派微型计算机的室内烟雾检测系统的设计与实现。本系统集合了嵌入式开发的模块化优点和计算机处理复杂问题的能力,而且可以长期稳定运行。检测系统是面向所有用户的,以实现超过设定浓度值报警为基础功能,结合温度湿度的录入,并且给用户提供可以对实时状态进行查询的渠道。     

基于树莓派B 微处理器的视频检测跟踪系统的实现

针对目前视频检测跟踪系统大多是在PC机上实现的现状,本文设计了一种基于树莓派B 微处理器的嵌入式检测跟踪系统,实现了视频检测跟踪系统的便携式小型化。在图像处理算法上本文采用帧间差分方法进行目标检测,通过形心标记进行目标跟踪。本系统采用基于Linux操作系统的树莓派B 微处理器进行算法移植,通过远程桌面连接工具或小型液晶显示器进行视频显示。实验结果表明,本系统可以很好的实现视频检测跟踪的基本功能。     

基于树莓派的LIS与Cobas6000联机通信的实践探索

文章针对医院检验科检验仪器需要使用台式电脑与LIS系统进行数据传输,进而造成实验室工作台空间使用率下降的问题,提出了采用一种仅有的信用卡般大小、价格低、高性能、低功耗的开源硬件平台—树莓派,并以LIS系统与Cobas6000自动生化分析仪之间数据传输解决方案为例进行实践探索。     

IRST对3D雷达引导性能分析

对于由红外和雷达组成的多传感器系统,分析和推导了用红外对3D雷达成功引导概率的解析表示式,给出了该成功引导概率随一些特征参数变化的七个规律,在多种情况下进行了成功引导概率的数值计算,验证了成功引导概率的性质,从而对研究和设计同地配置的红外对雷达引导系统具有一定的参考价值.     

IP分组的AAL3/4适配及性能分析

本文提出一种用AAL3/4适配IP分组,支持MPLS(多协议标签交换)的方法.给出单个分组经过基于信元的交换网络的端到端时延分析方法—"等价长度"法以及相应的结果,进行了仿真验证;并对此条件下接收端所需缓存容量进行了估计.研究表明,在实现VC合并时,采用AAL3/4适配能够获得较小的分组端到端时延,简化中间结点的操作并减小结点所需缓存容量.与其它方式(AAL5)相比,这是一种更好的适配方式.     

Performance evaluation of an architecture for the characterisation of photo-devices: design,fabrication and test on a CMOS technology

In this report, the performance of a particular pixel's architecture is evaluated. It consists mainly of an optical sensor coupled to an amplifier. The circuit contains photoreceptors such as phototransistors and photodiodes. The circuit integrates two main blocks: (a) the pixel architecture, containing four p-channel transistors and a photoreceptor, and (b) a current source for biasing the signal conditioning amplifier. The generated photocurrent is integrated through the gate capacitance of the input p-channel MOS transistor, then converted to voltage and amplified. Both input transistor and current source are implemented as a voltage amplifier having variable gain (between 10dB and 32dB). Considering characterisation purposes, this last fact is relevant since it gives a degree of freedom to the measurement of different kinds of photo-devices and is not limited to either a single operating point of the circuit or one kind and size of photo-sensor. The gain of the amplifier can be adjusted with an external DC power supply that also sets the DC quiescent point of the circuit. Design of the row-select transistor's aspect ratio used in the matrix array is critical for the pixel's amplifier performance. Based on circuit design data such as capacitance magnitude, time and voltage integration, and amplifier gain, characterisation of all the architecture can be readily carried out and evaluated. For the specific technology used in this work, the spectral response of photo-sensors reveals performance differences between phototransistors and photodiodes. Good approximation between simulation and measurement was obtained.     

Analysis of the Effects of Fringing Electric Field on FinFET Device Performance and Structural Optimization Using 3-D Simulation

In this paper, the potential impact of parasitic capacitance resulting from fringing field on FinFET device performance is studied in detail using a 3-D simulator implemented with quantum-mechanical models. It was found that fringing field from gate to source contributes significantly to FinFET performance and speed. The strength of fringing field is closely related to device features such as gate-dielectric thickness, the spacer width, fin width and pitch, as well as the gate height. For undoped fin with underlapping (nonoverlapping source/drain) gate, a thinner spacer with higher kappa value enhances the gate control of short-channel effects (SCEs) and reduces the source-to-drain leakage current. Our results also suggest that reducing the high- gate-dielectric thickness is no longer an effective approach to improve performance in small FinFET devices due to the strong fringing effect. However, the introduction of thin metal gate in a multifin device was found beneficial to device speed without compromising on current drive and SCE.     

Performance Analysis of 3D Localization for a Launch Vehicle Using TOA,AOA, and TDOA

Wireless Personal Communications - In general, a ground telemetry station for a launch vehicle (LV) includes a tracking function only; therefore, position measurements for LV depend on received...     

Enhancing Photovoltaic Performance Using an All‐Conjugated Random Copolymer to Tailor Bulk and Interfacial Morphology of the P3HT:ICBA Active Layer

Bulk heterojunction (BHJ) solar cells are fabricated using active material blends of poly(3‐hexylthiophene) (P3HT) donor, indene‐C₆₀ bisadduct (ICBA) acceptor, and an all‐conjugated random copolymer (RCP) additive. By optimizing RCP loading, power conversion efficiencies (PCEs) up to 20% higher than those of a binary P3HT:ICBA mixture are achieved. The improved device characteristics are rationalized in terms of the differences between the photoactive thin film morphologies. Energy‐filtered transmission electron micro­scopy reveals that incorporation of the RCP improves the degree of structural order of the BHJ fibrillar network and increases the extent of microphase separation between P3HT and ICBA. Additionally, a combination of atomic force microscopy and X‐ray photoelectron spectroscopy analysis indicates segregation of the RCP at the free interface, leading to a shift in the surface potentials measured by Kelvin probe force microscopy. These changes, both in the bulk morphology and in the interfacial composition/energetics, are correlated to improved carrier collection efficiency due to a reduction of non‐geminate recombination, which is measured by charge extraction of photo­generated carriers by linearly increasing voltage.     

硅基LiNbO3薄膜的工艺研究及其性能分析

利用射频磁控溅射法在硅衬底上生长c轴取向LiNbO3薄膜.研究了生成高质量薄膜的实验条件和快速退火处理对薄膜结晶质量的影响.发现以600℃衬底温度制备薄膜并以650℃进行快速退火时获得了具有优异结晶质量的LiNbO3薄膜.采用扫描电镜分别对薄膜的表面、截面进行了分析.结果表明,薄膜表面光滑,晶粒均匀致密.     

交叉型TE/TM模分离器的研制

采用光束传播法（ＢＰＭ）计算了交叉型ＴＥ／ＴＭ模分离器的偏振串音（ｃｒｏｓｔａｌｋ）。通过结构参数的优化，理论计算的偏振串音为－２３．７ｄＢ（ＴＭ）和－２２．８ｄＢ（ＴＥ）。同时制成相应的器件，测试结果表明，理论计算与实验是一致的     

Performance of RS-BCH Concatenated Codes and BCH Single-Stage Codes on an Interference Satellite Channel

In this correspondence, a model is analyzed that was designed to study interference on satellite channels. We developed this model to obtain performance results for a coherent phase-shift keyed (CPSK) system in which RS-BCH concatenated codes and BCH singlestage codes are applied to a satellite channel corrupted by cochannel interference. These results make use of earlier work on performance analysis of anm-phase CPSK system operating in the presence of random Gaussian noise and non-Gaussian interference. Earlier work on performance evaluation of concatenated codes on an equierror channel is also used. Our model incorporates features that account for the burst behavior of the interference sources. Results indicate that the use of RS-BCH concatenated coding provides significant performance improvement over no coding as well as single-stage BCH coding.     

Performance evaluation of an optical transparent access tier based on PON and spectral codes

The increasing amount of bandwidth requirements and quality of service needs for the next-generation access networks has boosted extensive research in the fiber-optics communication field. In this light, passive optical networks (PONs) combined with optical code division multiple access (OCDMA), provide a potentially cost-effective solution to meet such bandwidth demands. This work proposes an optical transparent architecture which enables all-optical communication between the network nodes. The encoded data streams are multiplexed at a merging point which results in multiple user interference (MUI), thus significantly reducing the network throughput. The networking nodes are able to monitor and record user activity in the PON, and further register the (past) state of activity at the merging point. In this work, we study the coherence of state between the networking nodes and the merging point, for different packet size distributions, in order to predict an optimal transmission instant of each node's data packets. We note that the states are coherent depending on the packet size distribution.     

一种基于LabVIEW和第三方驱动程序的无线电环境自动测试平台

一种基于LabVIEW和第三方驱动程序的自动化无线电环境测试平台,分别由天线控制转台、总控电脑、频谱仪三部分组成,其中总控电脑分别与天线转动平台、频谱仪相连;而集成于总控电脑中的控制程序包括实时天线转动平台控制和频谱仪控制两个子模块,其中实时天线转动平台控制模块通过串口向天线转台下发当前的方位、俯仰值,频谱仪控制模块通过网线将总控电脑与频谱仪相连具有设置控制频谱仪的观测参数,读取观测数据的功能.     

PZT基复合材料的3D打印制备及其柔性传感性能研究

为提高柔性可穿戴传感器的电信号输出能力,设计并制备了以聚二甲基硅氧烷(PDMS)为基体,锆钛酸铅(PZT)为压电相的0-3型压电复合材料。并探究了不同固相含量对浆料流变性能的影响。结果表明,浆料的粘度与剪切模量随银修饰PZT质量分数(w(PZT))的增加而增加,w(PZT)=38%时浆料屈服点为398.1 Pa,具有最优的可打印性。在电信号测试中,经银修饰样品最大电压峰-峰可达20.54 V,约为未经银修饰样品最大电压峰-峰值的5倍。弯曲测试中,在长度之差ΔL=7 cm时,样品电压峰-峰值为55 mV,证明样品具备柔性传感性能。