An integrated model for structure optimization and technology screening of urban wastewater systems

The conventional approach to wastewater system design and planning considers each component separately and does not provide the optimum performance of the entire system. However, the growing concern for environmental protection, economic efficiency, and sustainability of urban wastewater systems requires an integrated modeling of subsystems and a synthetic evaluation of multiple objectives. In this study, a multi-objective optimization model of an integrated urban wastewater system was developed. The model encompasses subsystems, such as a sewer system, stormwater management, municipal wastewater treatment, and a wastewater reclamation system. The non-dominated sorting genetic algorithm (NSGA-II) was used to generate a range of system design possibilities to optimize conflicting environmental and economic objectives. Information from a knowledge base, which included rules for generating treatment trains as well as the performance characteristics of commonly used water pollution control measures, was utilized. The trade-off relationships between the objectives, total water pollution loads to the environment, and life cycle costs (which consist of investment as well as operation and maintenance costs), can be illustrated using Pareto charts. The developed model can be used to assist decision makers in the preliminary planning of system structure. A benchmark city was constructed to illustrate the methods of multi-objective controls, highlight cost-effective water pollution control measures, and identify the main pressures on urban water environment.     

热带海岛地区大气环境容量研究

采用WRF-CALPUFF空气质量模型模拟了海南省不同季节大气污染物扩散特征,并基于模型模拟结果采用多目标线性优化方法估算了海南省主要工业园SO2和PM10的环境容量。研究表明:春季和秋冬季海南省大气污染受外来污染源影响大,本地源春季和夏季对大气环境质量影响较大;为保持环境空气质量一级标准要求,海南省主要工业园PM10和SO2的环境容量分别为7.32万,6.38万t/a。     

ON THE MISMATCH BETWEEN DATA AND MODELS OF HYDROLOGIC AND WATER RESOURCE SYSTEMS1

ABSTRACT: Many difficulties exist in the matching of models with data. This paper identifies elements of this problem and discusses considerations involved in model evaluation. The well known multivariate linear regression model is used to illustrate the distinctions between accuracy and precision and between estimation and prediction (because the model is commonly misused.) No amount of additional data will improve the accuracy of a poor model. A high R², while indicative of a good matching between the observed data and model estimates, is a poor criterion for judging adequacy of the model to make good predictions of future events. Model evaluation also includes the problem of introducing secondary data and proxy variables into a model. Secondary data frequently enter, for example, the mass, energy and water budget equations because of difficulties in measuring the primary variables. Proxy variables arise because of a desire to collapse a vector of incomparable values, say, of water quality into a single number. Review of the above issues indicates that model evaluation is a multi-criterion problem, often imbedded in a larger framework where models are intended to meet multiple objectives. The mismatch of models and data has increasing legal and social consequences.     

聚类分析和判别分析在安全评价中的综合应用

将多元统计方法中的聚类分析和Fisher判别分析综合应用于安全评价中,评价指标的系统效应权数有效避免了安全评价中人为赋予指标权重对评价结果的影响.分析了评价对象聚类的步骤和结果,探讨了评价对象所属安全等级的Fisher判别方法.最后通过对判别函数的分析与比较得出评价判别结果.     

危险品道路运输多目标路径优化方法研究

道路危险品运输路径优化是提高危险品运输安全的一项重要措施。通过对国内外文献的分析研究，本文提出了危险品道路运输路径优化的数学模型，该模型首先求出单项目标的最优解，然后找出每项目标的实际值尽可能接近各自单项的最优值。本文也建立了包括路线长度、时间、费用、路线风险、敏感目标人数在内的危险品道路运输目标体系，并给出危险品运输路线选择决策的程序，为政府相关部门进行路线选择提供决策依据。     

城市适度人口规模的多目标决策方法及应用

适度的人口规模是城市可持续发展的关键.针对人口研究的系统性和复杂性,本文提出一种城市适度人口规模的多目标决策方法,基于不同城市发展情景下资源要素供给状况与城市人口需求特征,计算供需关系共同制约下的适度人口规模.以北京市通州新城为案例应用该模型,结果表明,综合决策经济发展、社会生活和生态环境等影响要素,通州新城到2020年适度人口规模约为75～78万,规划期内就业、社会保障、供水、住房为约束人口规模的主要因素.     

煤矿瓦斯爆炸事故的应急救援物资调度模型研究

矿井瓦斯爆炸事故是煤矿安全生产中最严重的事故之一.为确保事故后应急救援的高效开展及减少应急物资调度过程中的经济损失,在以调度时间为第一的前提下,结合煤矿瓦斯爆炸事故实际,引入伤亡性和经济性两个优化目标,构建了一种在多出救点、多物资和多受灾点约束条件下的多目标应急物资调拨模型,并运用加权算法基本思想,确定了决策效用函数,同时结合瓦斯爆炸事故的时间紧迫度,在保证物资连续消耗的条件下,求解最优物资调度方案,并通过实例验证了可行性.     

基于不确定性多目标的规划环境影响评价研究

针对规划环境影响评价的特点 ,建立了基于不确定性多目标的规划环境影响评价模型 .并以沈阳市浑南新区发展规划的环境影响评价为例 ,对新区规划中的产业结构调整、污染物排放、资源利用、污水处理厂扩展等方面进行分析、优化 ,并为该规划的进一步完善提出了合理化建议     

Handling Three Types of Correlation in Contaminated Land Site Assessment

This paper outlines the three types of correlation that will characterise most attempts to model land contamination and optimise site assessment strategies. The first type of correlation is that which exists between indicators of contamination. A potential methodology for handling these correlations is given. The second type of correlation is the spatial (auto) correlation between different locations on a site. This has been previously handled through methods such as Kriging interpolation. The possible benefits of integrating the analysis of the first two types of correlation are very briefly discussed. The third type of correlation is that which exists between the information from site samples. Examples of this type of correlation are given.     

应用遗传算法优化氢气/空气燃烧反应系数

研究目的是优化氢气/空气简化反应机理的系数,使得简化机理在一定的误差范围内,能代替详细机理.通过计算氢气/空气详细反应机理得到的组分浓度作为遗传算法的适应度目标,对简化机理进行优化.结果显示,优化后的简化机理不仅在在计算组分浓度,而且在层流预混火焰速度和组分时空分布方面,更加接近详细机理所能达到的计算结果,比优化之前的简化反应机理计算结果更加准确.