发电公司报价辅助决策系统研究

为了适应电力市场的需要，建立了发电公司报价辅助决策系统。该系统在完成诸如成本分析等基本功能模块的基础上采用Internet技术，由信息浏览终端、应用程序服务器、历史及实时数据库服务器及防火墙等功能模块组成，其具体实现可以基于Windows系列操作平台及国内外流行的商用数据库平台，采用面向对象的程序设计方法，以VC 6.0等语言为主要开发工具。     

负荷时间序列波动性的动态时变结构研究

采用广义自回归条件异方差(GARCH)族模型分析了负荷时间序列波动性的动态时变结构,提出了模型系的概念,使用滚动数据窗技术估计了指数广义自回归条件异方差(EGARCH)和幂自回归条件异方差(PARCH)模型系;在研究动态显著性水平线(DSL)的基础上,探究了时序波动性的动态时变结构,讨论了贯穿各子样本空间的波动不对称效应。算例分析中,将所建模型应用于短期负荷预测,比较了GARCH族模型的预测能力,得到了较高的预测精度。     

汽轮发电机机组并网信号的采集和使用探讨

在实际生产过程中,汽轮发电机组并网信号或存在事故隐患,或者给单元机组运行方式带来诸多不便。为此通过两个电厂的典型问题进行分析、研究,得出切实可行的解决办法,并应用于生产中。     

M701F型燃气轮机的在线运行负荷特性

分析了重型燃气轮机负荷特性的影响因素,提出了研究重型燃气轮机负荷特性的技术路线。基于此,针对某M701F型燃气轮机,以国际标准化组织(International Organization for Standardization,ISO)的标准条件为基准,由机组的在线运行数据获得其负荷特性曲线,并建立负荷特性的数学模型。考察该燃气轮机6 940组实际数据,得出结论:当折算基准功率不小于18MW时,其负荷特性数学模型的最大相对误差不超过5.73%。     

Evaluation of wind load integration in disproportionate collapse analysis of steel moment frames for column loss

The design of steel structures, in most cases, depends majorly on the level of wind loads which are prescribed by codes and regulations and are used in the structural analysis due to the fact that steel structures being light and ductile systems are strongly affected from a slight difference in the values of wind loading. During the last decades, disproportionate collapse analysis has become of major interest mainly due to the increasing number of failures occurring in that pattern. Commonly accepted guidelines and methods of analysis have been produced, the most dominating of which being the Department of Defense Facilities criteria or DoD. In the DoD, as well as in other criteria, the event of a column loss is suggested as the modeling scenario which has to be sustained by a structural system in order to be robust. However, all the guidelines so far have disconnected the column loss analysis from wind loads and have only performed it for gravity loading. This paper presents the dynamic time history disproportionate collapse analysis of steel frames, including various levels of wind loading. Interesting aspects are discussed through the parametric analysis of five different numerical examples of moment resisting frames.     

高负载环境下基于Linux系统的防火墙软中断性能改善研究

当网络负载增大到一定程度后,基于Linux防火墙的数据转发性能开始下降。最常见的瓶颈是系统软中断在单一CPU上耗用达到100％。本文对这一问题进行了分析并提出了一种易于实现且性能改善明显的解决方案。     

The perception of hazard I. Hazard analysis and the contribution of visual search to hazard perception

Rockfall accidents are an important determinant of safety performance in deep level mining. Previous research which is reviewed suggests that a lack of skill in perceiving warnings of imminent danger may be an important factor contributing to this kind of accident. The perceptual task of mine workers is described briefly and a survey of the visual characteristics of dangerous rock is reported upon. The visual search performance of mine workers in a stope simulator, designed on the basis of the survey results, was studied. The findings show not only that novice mine workers, when compared with experienced men, lack the ability to search adequately in a simulation of dangerous rock, but also that their search skills can be improved significantly by training.     

利用弯矩影响线的移动荷载识别方法

基于模态叠加理论,通过桥梁多个截面处加速度响应数据,计算得到桥梁受移动荷载作用下的模态加速度.根据d'Alembertian原理,桥梁截面任意时刻的动弯矩可看作是任意时刻受惯性分布力和移动荷载作用下的静弯矩.利用影响线,建立起移动荷载与弯矩之间的关系,提出了一种利用弯矩影响线识别移动荷载的方法.算例表明,当荷载只有一个时,可由单点弯矩直接识别,当有多个移动荷载时,可基于多个截面的弯矩数据,利用最小二乘法可以有效的识别出任意时刻作用于桥梁上的移动荷载值.该方法避免了求解桥梁的动力学微分方程,识别精度高且过程简单,适合于工程应用.     

塑料材料的摩擦学性能研究综述

述了塑料材料摩擦、磨损的研究概况,详细阐述了摩擦因数、载荷、温度、速度、润滑、表面粗糙度pv值和热性能等因素对塑料材料摩擦性能的影响,介绍了磨损的衡量标准和测量方法.     

东莞理工学校人行通道涵承载力试验分析

介绍东莞理工学校人行通道涵静动载试验过程,借助MidasCivil专用有限元计算软件对该通道涵进行仿真分析,将试验实测值与理论计算值进行比较,据此评定该通道涵的承载性能。