POS技术及发展趋势

本文介绍了通过ＳＤＨ直接传送ＩＰ分组的方法－ＰＯＳ。文章详述了ＰＯＳ所涉及的两个主要问题：协议数据的封装,高速路由器的实现。文章还针对其它ＩＰ五ＡＴＭ结合的方案,给出了ＰＯＳ技术几个突出的优点,即高效率,可扩展性和简单可靠,并结合数据运营商的实际,描绘了ＰＯＳ技术的应用前景。     

无线POS行业应用在EGPRS网络中的解决方案

重点讨论运营商在维护集团客户的GPRS无线POS业务中发现的问题,并给出相关改进建议,以及升级至EGPRS网络后需要考虑的问题。     

Polymorphism and solidification kinetics of the binary system POS-SOS

As a first approach to modeling the crystallization behavior of cocoa butter, the binary system of its two major components, 1-palmitoyl-2-oleoyl-3-stearoyl-s n-glycerol (POS) and 1,3-distearoyl-2-oleoyl-s n-glycerol (SOS), was studied. Differential scanning calorimetry, coupled with polarized light microscopy, was used to determine the phase diagrams of the various polymorphic forms (the most metastable sub-α and α, intermediate δ and β′, and stable β). Associated theoretical phase diagrams were also built. The presence of a solid solution for β and the ideal behavior of α were confirmed. Kinetics of isothermal solidification as a function of temperature were studied for three compositions of the POS-SOS system. Results were displayed as time-temperature-transformation (TTT) diagrams and crystal morphology maps. Dependence of the crystallization kinetics on composition of the binary system was interpreted in terms of nucleation and growth mechanisms. The asymmetry of the POS molecule induces a slower growth rate of the mixture when the concentration of this triacylglycerol is increased. Solidification kinetics during continuous cooling were studied at various cooling rates for the system POS-SOS 25:75. Experimental results were compared with numerical predictions of a solidification model based upon TTT data and an additivity principle. The calculated and measured volume fractions of the different phases formed and times of onset and finish of the solidification were in good agreement.     

Crystallization kinetics of the pure triacylglycerols glycerol-1,3-dipalmitate-2-oleate,glycerol-1-palmitate-2-oleate-3-stearate,and glycerol-1,3-distearate-2-oleate

Crystallization kinetics of the three main components of cocoa butter, the triacylglycerols POP, POS, and SOS (where P, O, and S stand for palmitic, oleic, and stearic acids, respectively) were studied by combined differential scanning calorimetry and polarized light microscopy. The morphologies, nucleation kinetics, growth kinetics, and phases of the grains formed were identified with this system. The experimental data, as well as two different models to simulate crystallization and to predict behavior of the pure triacylglycerols, are presented. The first model is based on a macroscopical approach to solidification by using time-temperature-transformation (TTT) diagrams and the additivity principle. It allows prediction of the proportion of the different phases formed for any given thermal path imposed on the sample once the TTT diagram is known for the product. It is illustrated for SOS at constant cooling rates and is compared with experimental results. The second model directly simulates growth of the spherulites in the sample by using nucleation and growth rates that are determined experimentally. It provides a view of the structure as it would be observed with a microscope and shows evolution of the heat released in the sample. Isothermal solidification of POP at 15°C is displayed. The experiment and the model are in good agreement.     

张家港有线接入网双向改造规划方案

本文简要介绍了张家港在有线电视接入网中双向改造过程中,结合现有EPON及EoC产品的相关特性,对网络进行的系统规划。     

无线POS机数据传输安全控制策略研究

研究了无线POS机具的安全策略、GPRS的安全机制、防火墙的应用及银行前置的安全认证和数据加密的应用管理等内容。     

在线移动售电POS管理系统的实现

分析当前电力营销工作中数据采集和营销管理信息化现状,提出利用GPRS或CDMA无线通信网络,形成以客户营业厅、社会代收网点、购电营业点三级分布的在线移动售电营销网络,建立电费中心统一集中收费,社会代收、片区购电营业点就近购电,电费充值,用电监测闭环监控的电力营销售电在线管理系统。     

基于网络处理器的弹性分组环接入实现

弹性分组环技术是一种面向城域网的技术。在分析了网络处理器的优点之后,提出了一种基于网络处理器的弹性分组环接入方案,利用IXP1200实现了以太网和弹性分组环的接口转换,并讨论了方案的软硬件协同设计方法。     

POS机软件升级的方法与设计

该文介绍了POS（Point of Sales,销售点终端）系统中软件升级的方法,从中选出一种方法作为软件升级的案例,从硬件的设计开始,一直到软件的设计,详细说明了如何进行软件升级。     

网络处理器中微引擎设计

本文基于网络处理器中微引擎在POS口和千兆以太网口通信中的应用,详细叙述了千兆以太网端口和POS端口通信中微引擎设计的关键技术——多线程接收,线程间互斥和同步。为网络处理器中微引擎的软件设计提供了一些参考方法。