基于新技术的水力发电厂直流系统

介绍了采用新技术的流溪河发电厂直流系统。该直流系统采用总线控制方式,对所监测的模拟量、数字量无数量限制,其通道数可任意扩展;由于采用智能控制技术,系统具有较强的容错能力,而且响应速度快、噪音小、输出稳定,完全满足发电厂的安全生产要求。     

First-order side channel attacks on Zhang’s countermeasures

Zhang’s three countermeasures are known to be secure against certain first-order side channel attacks such as differential power analysis and correlation power analysis. This security comes from the countermeasures’ use of random points to blind the message and random integers to blind the secret scalar. In this paper, we propose first-order side channel attack methods that can perfectly break these three countermeasures. Even though Zhang’s countermeasures use random points and random integers our attacks are made possible by the fact that intermediate values computed by these countermeasures are dependent on specific values that we can guess. The experimental results verify that the proposed attack methods can successfully break existing countermeasures.     

A Faà di Bruno Hopf algebra for a group of Fliess operators with applications to feedback

A Faà di Bruno type Hopf algebra is developed for a group of integral operators known as Fliess operators, where operator composition is the group product. Such operators are normally written in terms of generating series over a noncommutative alphabet. Using a general series expansion for the antipode, an explicit formula for the generating series of the compositional inverse operator is derived. The result is applied to analytic nonlinear feedback systems to produce an explicit formula for the feedback product, that is, the generating series for the Fliess operator representation of the closed-loop system written in terms of the generating series of the Fliess operator component systems. This formula is employed to provide a proof that local convergence is preserved under feedback.     

Bayesian analysis of robust Poisson geometric process model using heavy-tailed distributions

We propose a robust Poisson geometric process model with heavy-tailed distributions to cope with the problem of outliers as it may lead to an overestimation of mean and variance resulting in inaccurate interpretations of the situations. Two heavy-tailed distributions namely Student’s t and exponential power distributions with different tailednesses and kurtoses are used and they are represented in scale mixture of normal and scale mixture of uniform respectively. The proposed model is capable of describing the trend and meanwhile the mixing parameters in the scale mixture representations can detect the outlying observations. Simulations and real data analysis are performed to investigate the properties of the models.     

Bayesian sample-size determination for two independent Poisson rates

Because of the high cost and time constraints for clinical trials, researchers often need to determine the smallest sample size that provides accurate inferences for a parameter of interest. Although most experimenters have employed frequentist sample-size determination methods, the Bayesian paradigm offers a wide variety of sample-size determination methodologies. Bayesian sample-size determination methods are becoming increasingly more popular in clinical trials because of their flexibility and easy interpretation inferences. Recently, Bayesian approaches have been used to determine the sample size of a single Poisson rate parameter in a clinical trial setting. In this paper, we extend these results to the comparison of two Poisson rates and develop methods for sample-size determination for hypothesis testing in a Bayesian context. We have created functions in R to determine the parameters for the conjugate gamma prior and calculate the sample size for the average length criterion and average power methods. We also provide two examples that implement our sample-size determination methods using clinical data.     

一种无接触供电的无线鼠标

介绍了一种无接触供电的无线鼠标设计电路,无接触电能发射装置采用USB供电,通过自激振荡电路产生了138 kHz的高频振荡电压;无接触电能接收装置采用感应耦合方式获取电能.无线鼠标用无线模块nRF24E1构成信号发射和接收电路,该电路除具备有线鼠标全部功能外,还可以离开电脑远距离灵活操纵鼠标.     

基于复杂网络理论的典型电力电子电路复杂性研究

基于复杂网络对电力电子电路的复杂性进行了研究,指出了复杂网络在电力电子技术中运用的结合点并以三相桥式全控整流电路及三相电压型桥式逆变电路为研究对象,提出用复杂网络的特征参数来分析该电路拓扑特性的方法,并对其鲁棒性及脆弱性进行了分析研究.最后对电力电子电路复杂性研究结果存在的问题进行了分析和总结.     

基于PIMS的船舶发电柴油机机旁操作仿真设计

选用组态软件PIMS,进行仿真系统设计.利用PIMS进行人机界面的编辑,根据船舶发电柴油机的工作原理和操作流程,完成后台脚本程序的编写.实现在PC机上进行船舶发电柴油机模拟操作,达到培训学员的目的.     

基于PIC单片机的GPIB数传系统设计

GPIB是仪器设备的主流通信接口之一.介绍一种基于GPIB的程控电源数传系统,详细介绍GPIB子卡的软硬件设计方法和基于Delphi平台的上位机软件编程思想.该技术已在某国产程控电源上使用,运行可靠,缩小了与国外同类产品的差距.     

基于低频能量分布的掌纹特征提取

提出了一种基于傅里叶变换的掌纹特征提取方法,利用傅里叶变换将空域的掌纹图像变换到频域,选取频域图像的低频能量分布作为掌纹的特征,以此为基础对特征向量进行匹配识别。实验结果表明,该算法实现简单、操作方便,具有较快的反应速度和较高的识别率。