SCTP应用于SIP消息传送的研究

简单介绍了SCTP协议的结构和内部功能以及SIP的会话过程．分析了SCTP适用于SIP传输层协议的特性,最后给出了SCTP应用于SIP的参数扩展及SIP消息到SCTP流的映射方式。     

基于NS2仿真的SCTP协议分析

本论文对SCTP协议进行了分析并用NS2软件进行了仿真。首先,介绍了SCTP协议内容和结构。其次,详细叙述了SCTP协议通信的建立与关闭过程。然后,阐述了利用NS2对SCTP进行仿真的方法并分析其结果。     

SCTP数据传输模式在SG中应用研究

信令流控制传送协议(SCTP)是根据RFC 2960(2000)建议制定的。SCTP协议主要用于在IP网中传送PSTN的信令消息。基于SCTP数据传输模式的基本功能,首先对比分析SCTP与TCP的特点和适用范围,对No.7信令与IP网互通的信令网关(SG)设备进行介绍,详细论述了在M2PA方式下SCTP的应用,并展望SCTP的发展前景。     

SCTP协议的研究与分析

分析了SCTP优于TCP、UDP的协议特性,介绍了SCTP的功能结构及其核心机制,讨论了SCTP在未来电信网络中的应用。     

SCTP数据传输过程的技术研究

流控制传输协议（SCTP）是IETF新近提出的一种传输协议，用于在基于IP的网络上传输PSTN信令。本详细研究了SCTP数据传输过程，特别是SCTP四路握手，并进一步展望了SCTP的发展前景。     

SCTP数据传输过程的技术研究

流控制传输协议(SCTP)是IETF新近提出的一种传输协议,用于在基于IP的网络上传输PSTN信令。本文详细研究了SCTP数据传输过程,特别是SCTP四路握手,并进一步展望了SCTP的发展前景。     

基于SCTP的TLS应用

简要介绍SCTP和TLS协议,探讨TLS应用于SCTP的特点及要注意的问题,给出简单的演示程序,演示了基于SCTP的TLS应用,最后得出结论:某些具体应用并不需要对SCTP关联中的流分别应用TLS协议,在单一流中的协商的TLS环境可简单的应用到其他流。     

流控制传输协议研究

文章介绍了流控制传输协议(SCTP)的主要特点:支持多穴主机,支持消息的无序递交,提供端到端的可靠性,提供面向消息的传输,提供相对TCP增强的流量控制和拥塞控制,提供更好的安全性和可扩展性;分析了SCTP的主要应用,强调作为一种通用的传输层协议SCTP是今后发展的方向;综合考察了当前SCTP的研究进展,并给出了相关结论,认为SCTP是一种功能强大的传输层协议.     

SCTP通路重传机制的实例分析

从Sigtran体系架构、SCTP协议入手,详细分析了一个SCTP的偶联的通路故障的实例,从而说明SCTP偶联的通路故障检测的机制。同时,本文特别指出了在IP承载下,超时重传的判断的机制的关键点。     

SCTP在无线网络上的最佳协议参数配置分析

本文研究了在WLAN、GPRS、UMTS这3种无线网络上运行流控制传输协议(SCTP)时,不同的协议参数配置对系统传输性能的影响。文中找出了达到最大系统传输性能时的SCTP协议参数设置,从而解决了符合IETF-RFC2960的SCTP应用于无线网络上协议最佳参数选择的关键问题。理论分析和仿真结果表明,运行于无线网络上时,采用了最佳参数配置的SCTP协议传输性能明显地高于采用传统参数配置的SCTP协议。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.     

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.