低压差分信号接口的优化设计

针对目前低压差分信号(LVDS)接口在高速长距离传输时容易出现失锁的现象,分别从电路和逻辑两方面对接口进行了优化设计。在电路方面,通过在电路中增加差分信号驱动器和自适应电缆均衡器,对信号进行增强和恢复;在逻辑方面,通过对接口通信协议的分析,提出了交替发送反码和增加标志位两种避免失锁的方法。实测结果表明,优化后的接口不仅有效地避免了失锁现象,保证了接口的可靠性,而且也提高了接口的传输速度。     

一种宽电压差电平转换接口电路设计

介绍了一种宽电压差电平转换接口电路的设计,充分利用通用的74HC系列芯片实现不同供电系统之间的高速、并行数据转换。本设计具有通用性强、设计简便、使用灵活、成本低、易操作、易于采购的特点。     

Opto22为英国垃圾填埋场提供基于以太网的控制系统

在发达国家,每人每年平均产生0．5吨－1125吨垃圾。但这些垃圾将堆在何处？根据美国环境保护协会统计,预计在美国每年将产生2.51亿吨固态垃圾,大约32.5％的垃圾是可回收或堆肥,12．5％的垃圾可焚烧,还有55％的垃圾进行填埋处理。在英国,垃圾填埋数据同样在攀升。目前,英国大量的市政垃圾（超过85％）被送至垃圾填埋场。     

一种矿井直流供电系统漏电检测方法

针对传统的接触网直流供电系统漏电检测方法中存在检测死区、母线对地电压偏离度过大等问题,提出了一种基于平衡电桥法与切换电桥法的新型漏电检测方法;分析了该方法的检测原理,从降低母线对地电压偏离度的角度出发,建立了平衡电阻与切换电阻的计算模型。Simulink仿真结果表明,该方法能够很好地降低母线对地电压的偏离度,提高了供电系统的稳定性。     

动车组单车自动校线及耐压试验方法

近些年随着动车组运行功能的不断提升和优化,车辆内部分布的电线电缆数量大量增加,接线测试点在校线、耐压试验环节人工测试付出的时间成本更多。为了避免人工失误影响产品质量,提高测试准确率,提高生产效率,使用自动化测试系统来替代人工试验。本文研制了动车组单车自动校线及耐压试验方法,测试可靠性高并能在不同动车组项目产品之间完成灵活转换,可缩短试验周期,提高测试效率,保障动车组生产的质量。     

Solutions of delay differential equations by using differential transform method

Differential transform method (DTM) is extended for delay differential equations. By using DTM, we manage to obtain the numerical, analytical, and exact solutions of both linear and nonlinear equations. In comparison with the existing techniques, the DTM is a reliable method that needs less work and does not require strong assumptions and linearization.     

Two-dimensional differential transform method,Adomian's decomposition method,and variational iteration method for partial differential equations

The implementation of the two-dimensional differential transform method (DTM), Adomian's decomposition method (ADM), and the variational iteration method (VIM) in the mathematical applications of partial differential equations is examined in this paper. The VIM has been found to be particularly valuable as a tool for the solution of differential equations in engineering, science, and applied mathematics. The three methods are compared and it is shown that the VIM is more efficient and effective than the ADM and the DTM, and also converges to its exact solution more rapidly. Numerical solutions of two examples are calculated and the results are presented in tables and figures.     

基于差分隐私的数据匿名化隐私保护方法

在保护数据隐私的匿名技术中,为解决匿名安全性不足的问题,即匿名过程中因计算等价类质心遭受同质性和背景知识攻击造成的隐私泄漏,提出了一种基于差分隐私的数据匿名化隐私保护方法,构建了基于差分隐私的数据匿名化隐私保护模型;在利用微聚集MDAV算法划分相似等价类并在匿名属性过程中引入SuLQ框架设计得到ε-MDAV算法,同时选用Laplace实现机制合理控制隐私保护预算。通过对比不同隐私保护预算下可用性和安全性的变化,验证了该方法可以在保证数据高可用性的前提下有效地提升数据的安全性能。     

一种改进的串联电池组单体电池电压测量方法

针对基于运算放大器和MOSFET管的串联电池组单体电池电压测量方法存在漏电流的问题,提出了一种改进的电压测量方法。在每节电池的两端增加了一个电压跟随器,可有效降低漏电流;增加了光电继电器作为运算放大器的电源开关,使电压测量电路在断电状态下不消耗电流;增加了一个稳压二极管,以防止MOSFET管被击穿。测试结果验证了改进方法的有效性。     

一种新型电池组单体电池电压检测方法

阐述串联电池组单体电池电压检测的现实意义.在比较现有检测方法的基础上,提出了一种结合开关矩阵和差分放大器的新型单体电池电压检测方法,详细设计了相关的电路,并给出实验结果.相对于目前的单体电池电压检测方法,该方法具有结构简单,测量精度高等优点.     

三相磁集成VRM的微分几何非线性控制研究

以三相磁集成VRM为研究对象,应用微分几何理论实现三相磁集成VRM的非线性解耦控制。在统一的开关脉冲函数下,基于微分几何理论得到三相磁集成VRM的状态反馈线性化解耦控制规律。建立三输入三输出仿射非线性模型,仿真实验表明,基于微分几何非线性控制的磁集成VRM具有良好的动态品质和稳态特性。     

Solving fuzzy differential equations by differential transformation method

An extension of the differential transformation method (DTM), which is an analytical-numerical method for solving the fuzzy differential equation (FDE), is given. The concept of generalised H-differentiability is used. This concept is based on an enlargement of the class of differentiable fuzzy mappings; to define this, the lateral Hukuhara derivatives are considered. The proposed algorithm is illustrated by numerical examples, and some error comparisons are made with other methods for solving a FDE.     

Numerical solution of fuzzy differential equations by predictor-corrector method

In this paper three numerical methods to solve “The fuzzy ordinary differential equations” are discussed. These methods are Adams-Bashforth, Adams-Moulton and predictor-corrector. Predictor-corrector is obtained by combining Adams-Bashforth and Adams-Moulton methods. Convergence and stability of the proposed methods are also proved in detail. In addition, these methods are illustrated by solving two fuzzy Cauchy problems.