经营成本变化对大庄电站经济效益的影响

我国水电蕴藏量居世界首位。近年来水电事业发展迅速,中小型水电项目的经济效益是投资者最为关注的内容,是影响投资者决策的首要因素。本文根据大庄水电站实际年运行费与设计阶段的经营成本对比,分析了经营成本变化的原因以及对项目经济效益的影响。分析结果显示,项目FIRR低于原设计标准,但高于新的财务基准收益率,项目连续亏损尚有其他原因,应做进一步分析。同时提出对经营成本与营业成本两个概念进行理论研究的建议。     

新余钢铁厂三期板坯连铸机系统分析

本系统分析建立在理论设计和实际应用的基础上总结的,其系统构成有很强的针对性,设计思想在其他行业中也可用到。本文比较详细的叙述了连铸系统的工艺流程;并且由于系统本身的扩展性较强,系统的适应性也比较强。     

基于PCS7的化工厂三废锅炉控制系统

介绍化工三废锅炉控制系统的设计和实现,以WinCC6.2作为上位机的组态软件,并采用S7-400系列PLC为核心的编程软件实现对下位机的控制。同时给出系统的硬件组成,PLC与现场仪器仪表的连接方式和通信方式,以及监控画面组态的实现。     

α-β和α-β-γ滤波在延时控制起爆算法中的应用

制导引信一体化起爆算法研究的一个重要方面就是通过对最佳起爆延时的估计来确定炸点,而对测量数据进行滤波从而提高炸点的估计精度是其中的一个必要环节。α-β和α-β-γ滤波算法ααα具有计算简单,工程中易于实现的特点。本文针对导引头测距测角模型中基于延时控制的算法,使用c＋＋builder工具进行仿真试验。研究结果表明在基于导引头测距测角模型进行起爆延时的计算中,α-β和α-β-γ滤波是可行的,同时根据仿真讨论了在滤波中影响炸点估计精度的因素及如何合理选取δ因子。     

基于Profibus的颜色采集系统的实现

颜色采集系统以Banner的QC50为颜色采集模块,采用伺服电机和相应控制器。主控制模块采用S7-300,通过PROFIBUS实现对电机的控制和颜色数据的传送,以工业计算机作为远程监控和数据存储处理。     

基于模糊控制的纸机蒸汽冷凝水控制系统

针对造纸干燥部的工况多变、选用传统控制方式不易控制的情况,设计了一种基于模糊PID算法设计的S7-300控制系统,介绍了理论上和实际组态、编程的实现方法。该系统鲁棒性强,可适应复杂工况,实际应用结果表明该系统算法合理、易实现,控制效果好。     

Innovative seismic design optimization with reliability constraints

Performance-Based Design (PBD) methodologies is the contemporary trend in designing better and more economic earthquake-resistant structures where the main objective is to achieve more predictable and reliable levels of safety and operability against natural hazards. On the other hand, reliability-based optimization (RBO) methods directly account for the variability of the design parameters into the formulation of the optimization problem. The objective of this work is to incorporate PBD methodologies under seismic loading into the framework of RBO in conjunction with innovative tools for treating computational intensive problems of real-world structural systems. Two types of random variables are considered: Those which influence the level of seismic demand and those that affect the structural capacity. Reliability analysis is required for the assessment of the probabilistic constraints within the RBO formulation. The Monte Carlo Simulation (MCS) method is considered as the most reliable method for estimating the probabilities of exceedance or other statistical quantities albeit with excessive, in many cases, computational cost. First or Second Order Reliability Methods (FORM, SORM) constitute alternative approaches which require an explicit limit-state function. This type of limit-state function is not available for complex problems. In this study, in order to find the most efficient methodology for performing reliability analysis in conjunction with performance-based optimum design under seismic loading, a Neural Network approximation of the limit-state function is proposed and is combined with either MCS or with FORM approaches for handling the uncertainties. These two methodologies are applied in RBO problems with sizing and topology design variables resulting in two orders of magnitude reduction of the computational effort.     

Augmented Panoramic Video

Many video sequences consist of a locally dynamic background containing moving foreground subjects. In this paper we propose a novel way of re‐displaying these sequences, by giving the user control over a virtual camera frame. Based on video mosaicing, we first compute a static high quality background panorama. After segmenting and removing the foreground subjects from the original video, the remaining elements are merged into a dynamic background panorama, which seamlessly extends the original video footage. We then re‐display this augmented video by warping and cropping the panorama. The virtual camera can have an enlarged field‐of‐view and a controlled camera motion. Our technique is able to process videos with complex camera motions, reconstructing high quality panoramas without parallax artefacts, visible seams or blurring, while retaining repetitive dynamic elements.     

An LMI approach to synthesis subject to almost asymptotic regulation constraints

A multi-objective controller synthesis problem is considered in which an output is to be regulated approximately by assuring a bound on the steady-state peak amplification in response to an infinite-energy disturbance, while also guaranteeing a desired level of performance measured in terms of the worst-case energy gain from a finite-energy input to a performance output. Relying on a characterization of the controllers with which almost asymptotic regulation is accomplished, the problem of guaranteeing the desired level of performance is reduced to solving a system of linear matrix inequalities subject to a set of linear equality constraints. Based on the solution of this system, a procedure is outlined for the construction of a suitable controller whose order is equal to the order of the plant plus the order of the exogenous system.     

control with limited communication and message losses

We propose an H^∞ approach to a remote control problem where the communication is constrained due to the use of a shared channel. The controller employs a periodic time sequencing scheme for message transmissions from multiple sensors and to multiple actuators of the system. It further takes into account the information on the random message losses that occur in the channel. An exact characterization for controller synthesis is obtained and is stated in terms of linear matrix inequalities. Furthermore, an analysis on the loss probabilities of the messages to accomplish stabilization is carried out. The results are illustrated through a numerical example.