非饱和土大气张力通用公式与库仑土压力

推出大气张力库仑土压力的近似计算方法：假设临界破裂角为已知,可以考虑多层粘性土、坡面任意荷载、水和气压力。提出粘性土的结合水膜可靠连接面积率修正系数等于粘粒含量。推出大气张力库仑抗剪强度公式的Cm 形式,Cm 是膜的抗剪强度贡献。     

DCS系统日常维护工作要点分析

以美国FOXBORO公司的I/ASeries系统为例,介绍DCS系统硬件及软件的日常维护工作要点。     

Inrush current estimation and hot-swapping for safe parallel battery pack

ABSTRACT

Batteries used in electric vehicles and microgrid applications use battery modules connected in series to satisfy the voltage required for each system, and battery modules are connected in parallel to increase capacity. In this parallel connected system, in order to disconnect and reconnect a specific battery module or to reconnect a new battery module, the battery module to be newly connected should have a small state of charge (SOC) difference from the existing battery modules. In particular, when a new battery is to be connected under a load current, there is a problem that excessive inrush current may occur in a specific battery module due to the load current distributed to each module and the current due to the SOC difference. Therefore, in this paper, we propose a method of estimating the inrush current through an equivalent electrical modelling analysis for the case where a battery module is newly added in a system in which the battery modules are connected in parallel. In addition, the power management algorithm for the battery pack system with inrush current estimation is presented. The proposed method is validated through simulations and experiments of a battery pack system in which 10 battery modules of 710V and 120Ah are connected in parallel.     

一种基于IP的适于数据中心网络的高速通信协议的设计

设计了一种C/S结构的、基于IP的自定义快速文件传输协议CFFTP (customized fast file transport protocol)协议,简述了协议交互流程,以及协议的软件实现流程。该协议能充分利用数据中心局域网下的丰富带宽资源,实现数据、文件的可靠快速传输。仿真结果显示,数据传输速率可达近10Gbps的线速,实验结果显示,虽然受到Server端磁盘文件读取速度的影响,数据传输速率仍然可以达到6Gbps的最高速率。     

永磁同步电机参数辨识研究综述

永磁同步电机(permanent magnet synchronous motor,PMSM)参数的实时准确获取,是实现PMSM高性能控制、可靠状态监控的重要前提和早期故障诊断的有效手段,为此,PMSM参数辨识技术获得众多学者的广泛研究关注且取得了长足发展,呈现出大量的研究和应用成果。该文在对既有文献归纳梳理的基础上,首先分析PMSM参数变化的原因,总结PMSM单参数和多参数辨识的技术成果,再对PMSM辨识方法进行归纳和比较,最后,揭示PMSM参数辨识过程中亟需关注的研究问题并展望其未来的发展方向,旨在实现PMSM系统的高效可靠运行。     

Reliability of dynamic systems in random environment by extreme value theory

A practical method is developed for estimating the performance of highly reliable dynamic systems in random environment. The method uses concepts of univariate extreme value theory and a relatively small set of simulated samples of system states. Generalized extreme value distributions are fitted to state observations and used to extrapolate Monte Carlo estimates of reliability and failure probability beyond data. There is no need to postulate functional forms of extreme value distributions since they are selected by the estimation procedure. Our approach can be viewed as an alternative implementation of the method in [7] for estimating system reliability. Numerical examples involving Gaussian and non-Gaussian system states are used to illustrate the implementation of the proposed method and assess its accuracy.     

不确定关联大系统鲁棒分散可靠控制

针对一类具有不确定性关联大系统，研究其鲁棒分散可靠状态反馈控制器的设计方案，采用该方案设计的可靠控制系统，不仅在系统运行良好的条件下，而且在系统的执行器元件出现失误的情况下，仍能确保系统内部状态的稳定性，并同时满足给定的性能指标。     

共享内存技术在Radius服务端应用中的研究

随着上网用户的激增，电信级的Radius应用服务器的性能问题越来越受到关注，研究一种软件实现的稳定、高效多进程通讯的同步机制，解决可靠提升接入认证服务器整体性能的问题，现实中采用了共享内存结合可靠信号量和原子变量技术，实现共享内存锁机制，应用于Radius服务中，深入细致剖析共享内存锁机制是如何避免访问冲突的，提供了新的思路。在实践中满足了百万级用户的认证授权要求，在服务端性能调优方面起着重要的作用。     

雷达组网中的IP实时可靠多播

随着Internet的发展,要求一对多或多对多通信形式的网络应用迅速增长,IP多播服务为该类网络应用提供了一种有效的通信手段。但是基于IP的多播是一种无连接的数据传输方式(UDP),UDP数据传输是一种“尽力而为”的方式,因此在传输过程中存在丢包和乱序现象。对于某些应用,该传输的不可靠性是不允许的,因此出现了可靠多播技术。可靠多播协议的应用针对性很强,不同的应用场合对可靠多播的要求以及实现方法也大不相同。文中分析了雷达组网对多播及其实时性和可靠性的需求,参考现有的解决可靠多播主要问题的方法,初步提出了一种适合于小批量数据分发的实时可靠多播通信协议的设计方案。