ERP软件管理技术在我国的应用分析

随着科技的高速发展,现代化的建设中不可缺少的运用多种管理软件,ERP作为一种新型的企业管理模式系统,是信息时代的高级管理方式,在企业的各项管理运作中优化组合,提高了管理能力.本文就EKP软件在我国的应用进行了简单的分析.     

PLC在组合机床控制中的应用

本文介绍了PLC对组合机床的控制,分析了其工作原理,详细介绍了其硬件配置和软件设计.     

在线自学与考试系统的设计

本文将现有的在线自学与在线考试系统相结合,设计出一个具备教学与测试的完整的学习系统,并实现学习者学习进度记录、进度相互比较及经验交流等功能,使学习者在学习过程中并不孤独。     

Modeling and simulation for a drop-impact analysis of multi-layered printed circuit boards

Multi-layered printed circuit boards (PCBs) contain a multi-layered structure that is suitable for high-speed and high-frequency applications. Hence, they are used extensively in electronic packaging assemblies for high-density applications. However, numerous composite parts and complex material properties of multi-layer PCBs complicate the reliability simulation of PCB model. This paper deals with a finite element analysis intended to describe numerically the behavior of multi-layered multi-materials PCB model (combination of metallic and composite plies) in the drop-impact performance. Through the comparison of physical drop test results, the fully multi-layered model illustrates higher accuracy if compared with that of the traditional simplified isotropic model and orthotropic model. The effects of material properties for the multi-layer PCB under drop-impact shock have also been investigated.     

RS-485总线型通讯系统应用

通过举例说明，本文介绍了用RS-485构成主机方式通信风格的应用组网方法。     

A novel integrated silicon capacitive microphone-floating electrode“electret” microphone (FEEM)

A novel principle “electret” microphone, i.e., floating electrode electret microphone, is proposed and implemented in this study. Single-chip fabrication and corrugation technique are used in the design and fabrication of the microphone. The floating electrode is encapsulated by highly insulated materials to ensure that there is no electric-leakage passage between the floating electrode and the electrodes of the microphone. Net-free electronic charges (not “bonded” charges as in traditional electret) in the floating electrode can excite the electric field, which is similar to that of the traditional electret. The floating electrode can be easily charged by use of the “hot” electron technique, available using the avalanche breakdown of the p⁺-n junction. Therefore, the electret microphone is rechargeable, which can greatly increase the lifetime of the device. The preamplifier has been on-chip integrated in a junction-field-effect transistor (JFET) source-follower type with resistors by use of ion implantation. Electret charges are banded in a deep potential trap, thus, this microphone can operate at a high temperature (as high as 300°C) and has high stability and reliability. Experiments show that the prototype has a 3-mV/Pa sensitivity and a larger than 21-kHz frequency bandwidth in a 1 mm ×1-mm diaphragm area. Microphone performance can be further improved by optimized process and design. The fabrication is completely integrated-circuit (IC) compatible, hence, the microphone shows promise in integrated acoustic systems     

Estimating light vectors in real time

Capturing the appearance of objects under different lighting conditions is useful in texture acquisition, bidirectional reflectance distribution function (BRDF) measurement, and image-based data acquisition. With the acquired data, we can render virtual objects realistically. During the data capture, we must record both the radiance and the light vector. Measuring the light vector is not necessarily easy. We propose a capturing system that estimates the light vector by applying a vision-based technique. It lets the user freely position a handheld light source during capture. The system estimates light-source orientation in real time through a Web cam mounted on the light source. Software running on an ordinary PC analyzes images from the Web cam to recognize the light source direction (the light vector). Our goal is to design a low-cost, portable, and adaptable system. Vision-based approaches offer such characteristics. We use a pose-estimation system to acquire image-based data for relighting.     

在输电网络开放环境下电力市场运行和购电合同的设计

探讨了开展发电企业向大用户直接供电的条件，提出了一种输电网络开放环境下的电力市场运营模式，即中长期金融合的交易和实时平衡市场相结合的电能交易模式。这种模式使市场竞争主体能够有效规避市场风险但又不降低市场竞争力度，而且市场主体之间的合约履行又不制约电网的安全可靠运行，市场运作简单、高效、透明。     

基于双输入模糊控制策略的电力系统频率控制

电力系统一般都很复杂且变量又多,实现二阶负载-频率自动控制也相应变得很困难.对此,把误差和误差变化率作为模糊控制器的输入,使得模糊控制器对较小误差具有较强的敏感性,这样有利于消除稳态误差,以适应误差的快速调节和精确调节.仿真结果表明这种模糊控制的策略对于存在扰动且并不是很大的情况是很适用的,提高了系统的稳态性能,减小了响应的超调.