嵌入式LonWorks网络智能网关设计

为了解决LonWorks设备现场智能控制及远程监控的需要,提出了通过嵌入式网关实现LON网和以太网协议的转换方案.本网关采用电力线收发器PL3150和带有以太网控制器的微处理器LPC 1778分别实现LonWorks网络和以太网的接口功能.同时还利用LPC 1778内置以太网控制器搭建Web服务器,实现了一个远程监控平台,达到了远程智能交互与监控的目的.本文给出了该智能网关硬件平台和软件平台的方案和实现方法.     

基于ZigBee和3G的智能家居远程监测系统设计

设计了以OMAP3530为核心的嵌入式平台并采用Android系统的家庭网关,搭建ZigBee无线传感网络实现家居有关信息的采集并传输到家庭网关,远程手机终端可通过3G网络与家庭网关建立连接,实现了家居环境的本地、远程移动监控和短信报警功能.开发的基于Android操作系统的家庭网关和远程手机终端软件UI界面友好,易于移植和使用.此外,对ZigBee网络通信数据进行AES加密,以保障数据的私密性和家庭无线传感网络的安全性和稳定性.结果表明：该系统采集数据精度较高且性能稳定,有良好的安全性和扩展性,具有很强的推广应用价值.     

基于ARM的智能家庭网关

本文给出了一种基于ARM的智能家庭网关的实现方法.硬件采用高速低功耗的32位微控制器ARM,软件系统采用在嵌入式实时操作系统uC/OS-Ⅱ平台上开发,实现了TCP/IP协议栈和HTTP协议,建成了一个嵌入式Web Server,用于实现远程Web访问.通过本智能家庭网关可以实现对各种家电设备的远程监控,同时也可以在本地实现同样的操作.本方法实现的智能家庭网关具有开发快、稳定性好、成本低、体积小、功耗低等特点,是一种比较理想的方案.     

基于ModBus协议的物联网环境监测系统开发

基于工业现场总线ModBus协议设计集Zigbee、WIFI、433 MHz物理层通信方式的物联网环境监测系统,网关硬件平台选用基于CortexTM-A8架构的Samsung S5PV210处理器,采集终端选用STC12C5A16S2、CC2530单片机;系统网关软件平台选用Linux内核,采用Qt/Embedded构建平台的嵌入式GUI系统,同时集成USB摄像头、RFID刷卡器等功能;远程云服务器平台采用第三方物联网平台,在网关部署shell脚本,运行调用CURL工具,实现与云端服务器的数据传输.系统设计具有实时性、实用性和可扩展性等优点.     

基于Tomcat的SSL VPN网关服务器的设计与实现

随着企业信息化程度的加深,安全套接层虚拟专网(SSLVPN)技术逐渐成为企业用户远程安全接入的重要方式.SSL VPN 网关服务器承担着代理远程客户端访问内部服务器的重要任务,主要实现Web转发功能.着重介绍基于Tomcat的Web转发功能模块的设计与实现.     

基于Cortex-A9的智能家居控制系统的硬件设计与实现

本文介绍了基于Cortex-A9的智能家居控制系统的设计方案,该控制系统以ARM平台Cortex-A9系列Hi3798C芯片为控制核心,集成了音视频模块、Wi-Fi模块、Zig Bee模块、3G/4G模块、智能配电管理和本地存储等功能模块,具有智能家居网关、无线路由器、机顶盒和家庭服务器等功能。通过此控制系统可以实现智能家居的面板化控制操作和手机APP的远程控制,在家庭有线网络通信异常时,仍可以实现智能家居的远程状态监控和家居控制,具有较高的安全性和实用性。     

IGRS和ZigBee协议转换的家庭网关设计

为了实现家庭内部不同网络内的设备间信息互通,通过分析和研究现有家庭网关的网络结构,文章设计了一种可实现IGRS和ZigBee协议转换的家庭网关,并详细叙述各模块的功能和实现方式。该网关可实现家庭内部异构设备间的信息交互,并支持远程控制和管理等功能。具有低成本、服务范围广泛等优点。     

基于云服务的远程数据传输系统的设计与实现

云服务数据传输是一种新型信息通信方式。在无线传输技术和嵌入式系统技术基础上,针对野外数据采集难以远程收集与分析的问题,设计了一种结合ZigBee本地低码率无线数据的系统。选用硬件开发平台STM32F407单片机作为网关,增加GPRS模块与云服务器的连接,大幅拓展数据传输的距离,实现远程计算机监测分布式信息采集情况,随时随地能了解到野外节点的工作实况。经测试,系统可以通过登录云端服务器读取到前端所采集的数据,运行准确可靠。     

在城域网重构背景下的虚拟化家庭网关实现方式

虚拟化家庭网关由实体网关和虚拟网关构成,两者通过逻辑用户连接互联。研究了城域网络重构背景下虚拟化家庭网关的实现方式,首先对传统家庭网关进行测试,证实某运营商现网的光猫大部分在配置成网桥模式并关闭DHCP功能后可以作为实体网关使用,然后提出可以从功能集中式独立服务器模式平滑演进到功能分布式模式的虚拟网关部署方案,最后使用VxLAN、EVPN VPLS技术跨IP网络承载逻辑用户连接以太帧,对现网影响小。此外,对基础服务、增值服务、隐私以及安全问题进行了探讨。     

基于GM8180的网络视频服务器的软件设计

为了实现远程数字化视频监控,设计了网络视频服务器。网络视频服务器主要完成对监控现场的音视频信号和报警信号的实时采集和处理,然后通过网络传输到监控中心,此外,可以接收监控中心发送的控制指令。在分析升迈科技公司的GM8180芯片的性能特点的基础上,提出了基于GM8180实现网络视频服务器的方案。先简单介绍了网络视频服务器的应用方式和GM8180的特点,然后详细介绍了网络视频服务器的功能和软件设计。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.