Parameter Sensitivity and Predictive Uncertainty in a New Water Quality Model, Q2

A new dynamic model of water quality, Q2, has recently been developed, capable of simulating large branched river systems. This paper describes the application of a generalized sensitivity analysis (GSA) to Q2 for single reaches of the River Thames in southern England. Focusing on the simulation of dissolved oxygen (DO) (since this may be regarded as a proxy for the overall health of a river); the GSA is used to identify key parameters controlling model behavior and provide a probabilistic procedure for model calibration. It is shown that, in the River Thames at least, it is more important to obtain high quality forcing functions than to obtain improved parameter estimates once approximate values have been estimated. Furthermore, there is a need to ensure reasonable simulation of a range of water quality determinands, since a focus only on DO increases predictive uncertainty in the DO simulations. The Q2 model has been applied here to the River Thames, but it has a broad utility for evaluating other systems in Europe and around the world.     

协同办公平台项目实施的解决方案

软件实施活动的目的是生产可执行的软件单，该文将软件工程的相关知识应用到项目实施中，提出了一套标准化的软件项目实施过程，实践性较强。     

浅谈密山灌区水田典型区设计

阐述了密山灌区选择具有代表性的田块进行水田典型区设计的步骤与方法。     

UML在事务流程描述方面的扩展

文章提出了可视化的基于事务流程的符号定义和描述方法,即单证流,控制流和数据流,三流合一的方法,用以扩展UML中的用例分析,以此推动特定行业的应用系统的需求描述和建模。     

机械产品需求分析建模及其在石材设备开发中的应用

在总结需求分析的概念和目前研究现状的基础上，根据机械产品需求的特点提出需求分析建模的方法，在建立产品需求数据库的基础上，通过对需求分析结果的功能化语义表达和规范化，根据对产品需求表述的语义分析，得出形式化的产品需求描述结果，并将该模型应用于石材异型制品加工设备的需求分析中。     

遗传算法用于水资源工程中的理论和应用研究

基于遗传算法的运行机理和交叉思想,文章把遗传算法的基本原理、分析技术和先进算法较完整地引入水资源工程领域,研制了适用于水资源工程问题的标准遗传算法的3种改进方案,即基于二进制编码的加速遗传算法(AGA)、基于实数编码的加速遗传算法(RAGA)和基于整数编码的单亲遗传算法(IPGA),建立了基于AGA的门限自回归模型、基于AGA的门限回归模型、基于AGA的双线性模型、基于RAGA的逻辑斯谛曲线等级评价模型、基于RAGA的投影寻踪等级评价模型。并把这些模型成功地用于地下水预测、海洋冰情预测、河道洪水预测、径流预测、旱涝序列预测、洪水灾情评估、水质综合评价等实际问题中。研究结果说明,遗传算法在处理实际水资源工程复杂优化问题中具有广泛的应用价值,值得进一步研究和探索。     

需求管理的一个系统解决方案

需求管理是需求工程的一个子工程。文章论述了需求工程中的需求管理，在探讨需求管理本质的基础上分析了现有的需求管理系统，提出了一个需求管理的系统解决方案。     

面向对象技术中标识对象的策略

面向对象（OO）分析模型的核心是对象，如何找出这些对象是OO技术所面临的中心挑战。对标识对象策略的探讨，有助于对OO技术的深入理解和掌握。本文结合需求文档分析工具的对象标识，对相关的问题进行了讨论。     

平面绕流泥沙磨损试验及水轮机磨损预估

本文介绍室内平面绕流磨损试验结果和应用于真机的磨损预估，与刘家峡、葛洲坝机组实测磨损量核算结果差别不大。在此基础上对在建的小浪底机组做了估算，并提出了一些看法。     

Application of an expert system using neural network to control the coagulant dosing in water treatment plant

The coagulation process is one of the most important stages in water treatment plant, which involves many complex physical and chemical phenomena. Moreover, coagulant dosing rate is non-linearly correlated to raw water characteristics such as turbidity, conductivity, PH, temperature, etc. As such, coagulation reaction is hard or even impossible to control satisfactorily by conventional methods. Based on neural network and rule models, an expert system for determining the optimum chemical dosage rate is developed and used in a water treatment work, and the results of actual runs show that in the condition of satisfying the demand of drinking water quality, the usage of coagulant is lowered.