A HYBRID OPTIMIZATION APPROACH TO THE ESTIMATION OF DISTRIBUTED PARAMETERS IN TWO-DIMENSIONAL CONFINED AQUIFERS1

ABSTRACT: In using non-linear optimization techniques for estimation of parameters in a distributed ground water model, the initial values of the parameters and prior information about them play important roles. In this paper, the genetic algorithm (GA) is combined with the truncated-Newton search technique to estimate groundwater parameters for a confined steady-state ground water model. Use of prior information about the parameters is shown to be important in estimating correct or near-correct values of parameters on a regional scale. The amount of prior information needed for an accurate solution is estimated by evaluation of the sensitivity of the performance function to the parameters. For the example presented here, it is experimentally demonstrated that only one piece of prior information of the least sensitive parameter is sufficient to arrive at the global or near-global optimum solution. For hydraulic head data with measurement errors, the error in the estimation of parameters increases as the standard deviation of the errors increases. Results from our experiments show that, in general, the accuracy of the estimated parameters depends on the level of noise in the hydraulic head data and the initial values used in the truncated-Newton search technique.     

维多利亚蓝B与碘在水溶液中的显色反应-吸光光度法测定海产品中的碘

研究了水相中,维多利亚蓝B与碘离子(I~-)的显色反应.当磷酸浓度为1.6mol/L,聚乙烯醇为0.08％时,维多利亚蓝B与碘形成络合比为1∶3的络合物,最大吸收峰位于375nm处,表观摩尔吸光系数为1.02×10~4L/mol·cm,碘在(0～16)μg/ml范围内符合比耳定律.方法可用于海洋生物等样品中的微量碘测定,结果满意.     

油类物质测定的几个影响因素及改进

通过用重量法测定水中油类物质的几个影响因素的研究，得出了能够取得满意测定结果的方法．改进后的方法，减轻了工作量，节省了分析费用，有利于批量分析．     

有关pH值预测模式的探讨

对目前使用较为常见的ｐＨ预测模式和方法进行了分析探讨，提出了各自的适用和范围和存在问题，并提出了比较合理的ｐＨ值预测模式和方法．     

飞机炮击环境分析及模拟方法研究(下)

从飞机炮击环境的特性出发，指出GJB150．20－86窄带随机加宽带随机飞机炮振试验方法的局限性以及应用傅立叶分析方法分析炮击信号的不合理性，提出应用时－频联合分析方法进行炮击信号分析的可行性以及小波（Wavelet)分析技术用于炮击信号中确定性信号和非平稳随机信号分离的应用途径。最后，提出适用实验室炮击环境模拟的脉冲方法（Pulse Method)数学模型。     

星座图法在大气质量评价中的应用

利用星座图法进行大气质量评价,优化了路径权值的算法,得出的星座图在两维颊内具有同样模式距离接近和不同模式距拉开的特点。     

双柱双检测器气相色谱法同时进样分析非甲烷烃

介绍了用双柱双氢火焰离子化检测器同时进样气相色谱法分析气体样品中非甲烷烃.经过与现有方法的比较,该方法具有平行性更好、数据更准确、分析速度快等优点,各项指标均大大优于现行标准HJ/T 38-1999中的数据.通过软硬件的改进,解决了以前非甲烷烃在分析中由于在时间上所引起的数据倒置、分析误差等问题.     

大空间建筑消防系统故障风险定量分析的新方法

在对CO2自动灭火系统的故障模式、影响及危害度定性分析的基础上,采用模糊数学方法,以系统故障影响严重度、故障模式发生概率及其可检测性为关键指标,给出了故障风险定量评价指标的建立方法,提出了一种消防系统故障风险定量分析的新方法———模糊推理法。该方法可直接输入语言变量,利用模糊定性和不确定信息或数据定量评价系统的故障风险,并以CO2自动灭火系统为例,详细阐述了该方法定量评价故障风险的全过程。该方法和推理过程可为其他建筑防火设备的同类分析所借鉴,为城市火灾风险定量评价系统的构建提供理论基础和一种新方法。     

Equity and productivity assessments in the Olifants River basin, South Africa

Emerging approaches to water resources development and management typically highlight equity and productivity as two main objectives. In the context of integrated water resources management within a river basin, managers and stakeholders often need a comparative assessment of different options for water augmentation and/or allocation. Pitting such options against predefined objectives, such as equity and productivity, requires an assessment of the effects that available options will have on these objectives. Available documentation indicates that not only does the interpretation of such objectives vary widely, but also the available methods for assessing equity and productivity run into significant limitations in the availability of adequate data. This limitation has largely kept decision makers from gaining a comprehensive overview of equity and productivity scenarios, whether within or across sectors, that could facilitate better‐informed decisions. To address this methodological gap, this article scrutinizes different notions associated with equity and water productivity, and limitations in prevalent assessment methods with the view to develop and demonstrate pragmatic methodologies for assessing equity and productivity in data‐scarce contexts. The discussion and findings are based on a review of relevant literature and empirical and consultative research work in the Olifants River basin in South Africa. The demonstrated methodologies for assessing equity and productivity, besides being useful in data‐scarce contexts, are insightful for initiating several policy measures and also for exploring the relationship between equity and water productivity.     

企业安全效益的量化

安全就是效益 ,而安全效益的量化问题一直是企业非常关心的问题。笔者通过安全效益的论述、量化分析 ,提出了企业安全效益由安全管理所创造的直接经济效益、间接经济效益、安全投入转化的经济效益、潜在经济效益四部分组成的新观点 ;推导出安全效益的量化公式 ,从而揭示了安全与效益的辩证统一关系 ;得出了安全效益从定性走向定量是必然的规律和安全效益完全可以进行量化计算的重要结论。