工资邮件程序-为ERP提供完美支撑

本文主要对工资邮件程序的开发进行了分析介绍。首先介绍了本项目开发的背景,其次介绍了本项目的开发环境,最后详细介绍了ESMTP协议和EXCEL类库。     

SNC保护在故障测试定位中的应用

通过实例详细介绍了如何利用SNC保护测试来定位故障。文章首先介绍了具体实例的故障现象,接着介绍了测试方案和实施方法,然后着重介绍了测试过程。     

基于M600的便携终端显示界面设计

文章首先介绍了便携终端的组成和功能,然后介绍了北京迪文科技有限公司的M600人机界面驱动模组,接着介绍了便携终端显示模块的硬件构成,最后介绍了便携终端的显示界面设计。     

美国三大核武器实验室IT进展

简要介绍了美国三大核武器实验室近期IT基础设施的建设情况。首先对ESNet的主干网和涉密网SecureNet的建设和升级进行了介绍,并以LANL为例介绍了内部局域网的安全域划分;其次是对IT基础服务的介绍,并以SNL为例,介绍了其近年来的主要工作进展。     

数字集群越区切换的研究(上)

本文介绍了数字集群中越区切换的相关知识和实现方法.首先,介绍了越区切换的产生原因.然后,介绍了越区切换的典型实现方法.接着,以TETRA系统为例着重介绍了数字集群中越区切换的实现过程.包括切换前的测量、切换的策略和如何切换处理.最后介绍了越区切换的考核方法.     

ZigBee技术简介

首先介绍了ZigBee技术的由来．接着介绍了ZigBee协议栈的组成、网络拓扑、特点以及ZigBee技术的优点．最后介绍了ZigBee技术的应用。     

MMT技术概述和基于MMT的混合媒体传输

本文介绍了MPEG近期推出了一项新的标准,MPEG Media Transport (MMT),介绍了它所包含的关键要素,同时介绍了MMT功能区、接口以及端到端构架.并对混合媒体在异构网络中的传输做了案例分析,对于时钟同步方式做了介绍.     

TD-SCDMA/GSM/GRPS双模终端发展分析

首先介绍了双模终端的分类,然后介绍了双模终端的发展策略,最后重点介绍了双模终端在3G网络建设中的作用.     

Java虚拟机在机顶盒中的研究和移植

本文介绍了基于数字电视机顶盒的Java虚拟机的移植方法。首先简要介绍了Java语言,其次介绍了适用于数字电视机顶盒的Java虚拟机——CVM,并给出了CVM移植到数字电视机顶盒的方案和实现过程,其中重点介绍了多线程的实现方法,包括多线程的同步和协作等。最后介绍了测试平台的搭建。在这些工作的基础上,成功地完成了Java虚拟机的移植。     

基于现网的HSPA＋网络部署探讨

介绍了HSPA＋的演进,并结合珠海外场测试介绍了系统如何升级HSPA＋网络,同时简要介绍了测试结果,最终提出64QAM部署建议     

Filter-embedded design and its applications to passive components

A design in which a filter is embedded in a fiber fixed on a substrate is proposed. It was successfully applied to the fabrication of low loss fiber optic components for a single-mode fiber transmission system. These components have a wide operational temperature range. The design is easily adapted to a multifilter or multifiber component. Filter embedding is achieved in two ways. One is to insert a thin filter chip in a slit which is machined into a fiber fixed on a substrate by a dicing saw (filter inserted type). The other is to evaporate a filter film directly on a fiber end face and butt this fiber to another fiber on a guide groove on a substrate (filter evaporated type)     

Two-port active coupled microstrip antenna

A multilayer structure, based on a patch antenna coupled through a nonresonant slot to a pair of feeding microstrips is a versatile module which can be used as a radiating and resonating element in a number of different configurations. Direct connection to a low cost transistor in a feedback loop results in a very simple active antenna, as reported. Different termination conditions at the four microstrip ports give rise to a number of alternative configurations for active generation/detection and multipatch arrays.<>     

A Note on Loaded Line Synthesis (Correspondence)

The purpose of this note is to present an alternate derivation of a formula for the synthesis of a loaded line. The problem is to determine the values of the normalized susceptances a and c mounted an exact quarter-wavelength apart along a uniform line. These are arranged in the order a, c, c,. . .c, a to achieve a loaded line with a given phase shift and perfect match. In order to analyze a particular line design for standing-wave ratio and phase shift over a band of frequencies on a digital computer, it is worthwhile to know the values of the susceptances to many more decimal places than one would achieve from a simple graph.     

Virtual impedance control for a regional dynamic voltage restorer

A dynamic voltage restorer (DVR) can be installed in a middle-voltage (MV) power grid, to concurrently protect a cluster of sensitive loads from voltage sags. To further improve its efficiency and reduce the difficulty in its implementation, a novel control strategy for operating such a DVR as a virtual impedance in series with sensitive loads is proposed in this paper. In addition to its usual function of compensating for voltage sags, such a DVR can also operate as a virtual inductance, to function as a fault current limiter (FCL) during a downstream fault, or a virtual capacitance, to function as a series compensator (SC) to compensate the voltage loss along the feeder line during heavy load. Based on a dual-loop control design, strategies for operating a DVR as a series virtual inductance and a virtual capacitance are proposed, and methods for tuning the parameter values and a stability analysis of the whole system are presented. The feasibility and effectiveness of the proposed method are verified by simulations using the PSCAD software, and experimental results obtained using a prototype DVR are presented.     

Equivalent transformations for the mixed lumped Brune-type sectionand uniform transmission line

As an analytical method for nonuniform transmission lines (NTLs) equivalent transformations are extended to a more general case, namely a mixed lumped Brune-type section and a uniform transmission line (unit element, UE). Circuits consisting of a cascade connection of a lumped Brune section and a UE are equivalent to one consisting of a cascade connection of a nonuniform transmission line whose characteristic impedance distribution is expressed with a trigonometric function and a lumped Brune section. This equivalent transformation method is easily applied to a circuit consisting of a lumped C section and a UE. The equivalent circuit is a circuit consisting of an NTL and a lumped C section. In this case, the characteristic impedance distribution of the NTL may be expressed in terms of a hyperbolic function. Exact network functions of the NTLs are easily obtained from the equivalent circuits without solving the telegrapher's equation. By considering the limiting case of these equivalent transformations, equivalent transformations for circuits consisting of a cascade connection of a lumped resonance circuit and a circuit and a uniform transmission line are derived     

A 220-MHz pipelined 16-Mb BiCMOS SRAM with PLL proportionalself-timing generator

This 512 Kw×8 b×3 way synchronous BiCMOS SRAM uses a 2-stage wave-pipeline scheme, a PLL self-timing generator and a 0.4-μm BiCMOS process to achieve 220 MHz fully-random read/write operations with a GTL I/O interface. Newly developed circuit technologies include: 1) a zig-zag double word-line scheme, 2) a centered bit-line load layout scheme, and 3) a phase-locked-loop (PLL) with a multistage-tapped ring oscillator which generates a clock cycle proportional pulse (CCPP) and a clock edge lookahead pulse (CELP)     

Some Theoretic Results on a Digital EMG Signal Processor

As is well known, a general EMG signal processing scheme includes a prewhitening filter, a v-order detector, a smoothing filter, and a relinearizer. In this paper, a theoretical analysis of such a scheme is carried out, including a detector characteristic which presents a logarithmic behavior.     

WiFi access point pricing as a dynamic game

We study the economic interests of a wireless access point owner and his paying client, and model their interaction as a dynamic game. The key feature of this game is that the players have asymmetric information - the client knows more than the access provider. We find that if a client has a "web browser" utility function (a temporal utility function that grows linearly), it is a Nash equilibrium for the provider to charge the client a constant price per unit time. On the other hand, if the client has a "file transferor" utility function (a utility function that is a step function), the client would be unwilling to pay until the final time slot of the file transfer. We also study an expanded game where an access point sells to a reseller,which in turn sells to a mobile client and show that if the client has a web browser utility function, that constant price is a Nash equilibrium of the three player game. Finally, we study a two player game in which the access point does not know whether he faces a web browser or file transferor type client, and show conditions for which it is not a Nash equilibrium for the access point to maintain a constant price.     

In situ HREM study on the structural instability of isolated nanometre-sized alloy particles in the Sn-Bi system

The structural instability of isolated nm-sized alloy particles has been investigated by in situ transmission electron microscopy, using particles in the Sn-Bi system. In a pure tin (Sn) particle, no structural fluctuation was induced under electron-beam irradiation. In a tin-rich solid solution particle, an orientational fluctuation took place at a rate of approximately once per 1-3 s. In a high concentration alloy particle with a two-phase microstructure, a structural fluctuation occurred at a rate of a few hertz. Namely, the fluctuation became more frequent with increasing bismuth (Bi) concentration, no matter whether it consists of a single phase or multiple phases. A good parallelism can be found between this fluctuation enhancement with bismuth concentration and the fact that the free-energy difference between a solid particle and the corresponding liquid one decreases continuously with bismuth concentration and approaches a value close to zero at the eutectic composition. These results lead to a view that a nm-sized solid particle exhibits a structural instability under electron-beam irradiation when the free-energy difference between a solid particle and the corresponding liquid one is reduced to a value close to zero.     

A fast-settling CMOS op amp for SC circuits with 90-dB DC gain

A technique that combines the high-frequency behavior of a single-stage op amp with the high DC gain of a multistage design is presented. This technique is based on the concept that a very high DC gain can be achieved in combination with any unity-gain frequency achievable by a (folded-) cascode design. Bode-plot measurements for an op amp realized in a 1.6-μm process show a DC gain of 90 dB and a unity-gain frequency of 116 MHz (16-pF load). Settling measurements with a feedback factor of 1/3 show a fast single-pole settling behavior corresponding to a closed-loop bandwidth of 18 MHz (35-pF load) and a settling accuracy better than 0.03%. This technique does not cause any loss in output voltage swing. At a supply voltage of 5.0 V an output swing of about 4.2 V is achieved without loss in DC gain. The above advantages are achieved with a 30% increase in chip area and a 15% increase in power consumption