Improved Transferability of Data‐Driven Damage Models Through Sample Selection Bias Correction

Damage models for natural hazards are used for decision making on reducing and transferring risk. The damage estimates from these models depend on many variables and their complex sometimes nonlinear relationships with the damage. In recent years, data‐driven modeling techniques have been used to capture those relationships. The available data to build such models are often limited. Therefore, in practice it is usually necessary to transfer models to a different context. In this article, we show that this implies the samples used to build the model are often not fully representative for the situation where they need to be applied on, which leads to a “sample selection bias.” In this article, we enhance data‐driven damage models by applying methods, not previously applied to damage modeling, to correct for this bias before the machine learning (ML) models are trained. We demonstrate this with case studies on flooding in Europe, and typhoon wind damage in the Philippines. Two sample selection bias correction methods from the ML literature are applied and one of these methods is also adjusted to our problem. These three methods are combined with stochastic generation of synthetic damage data. We demonstrate that for both case studies, the sample selection bias correction techniques reduce model errors, especially for the mean bias error this reduction can be larger than 30%. The novel combination with stochastic data generation seems to enhance these techniques. This shows that sample selection bias correction methods are beneficial for damage model transfer.     

川东北地区须家河组二段储层差异性分析

随着勘探程度的深入，为了扩大四川盆地天然气勘探领域、寻找新的勘探接替区，四川盆地的勘探区域由盆内逐渐向盆缘延伸。在这种背景下，川东北地区须家河组二段相继取得新的勘探成果，但在勘探开发过程中逐渐暴露了诸如区块之间气井产能差异大，储层的碎屑组分、结构及厚度、物性、孔隙结构差异明显等问题，制约了勘探开发的步伐。针对上述问题，根据岩芯观察描述、分析化验资料及测井解释成果，从沉积、成岩方面入手，对比剖析了川东北龙岗和营山地区须二段储层特征的差异性及其成因，认为远离物源区和高能水体的反复淘洗是造成储层差异性的首要因素，强烈的压实作用和多期石英加大对储层差异性起关键作用，自生绿泥石衬边胶结和长石选择性溶蚀最终决定了储层差异性。从而解释了气藏勘探开发中遇到的诸多问题，对有效指导该区的下一步勘探开发工作具有重要意义。     

Design selection for strong orthogonal arrays

Strong orthogonal arrays (SOAs) were recently introduced and studied as a class of space‐filling designs for computer experiments. An important problem that has not been addressed in the literature is that of design selection for such arrays. In this article, we conduct a systematic investigation into this problem, and we focus on the most useful SOA(n,m,4,2 + )s and SOA(n,m,4,2)s. This article first addresses the problem of design selection for SOAs of strength 2+ by examining their three‐dimensional projections. Both theoretical and computational results are presented. When SOAs of strength 2+ do not exist, we formulate a general framework for the selection of SOAs of strength 2 by looking at their two‐dimensional projections. The approach is fruitful, as it is applicable when SOAs of strength 2+ do not exist and it gives rise to them when they do. The Canadian Journal of Statistics 47: 302–314; 2019 © 2019 Statistical Society of Canada     

水资源污染与水资源的减少

工业的发展在带给人类福音的同时 ,也给江河湖泊、地下水源及海洋造成了污染 ,并对人类的生存与发展构成了严重威胁     

白族本主神话中的水神崇拜

本主崇拜是白族的传统信仰 ,在大量的本主神话传说中 ,有一些与水有关的故事 ,反映了农耕经济对水的依赖及凝结于本主身上的原始崇拜的影子 ,还可以看到多种文化交流在这一特定领域里的反映     

粉煤灰在废水处理中的应用

介绍了粉煤灰的结构及物理化学特性，处理废水的机理，综述了国内外利用粉煤灰处理各种废水的最新研究成果。目前利用粉煤灰处理废水主要应用于城市污水、印染废水、造纸废水、制药废水、电废水、重金属废水及含酚、含氟废水的处理。同时介绍了几种粉煤灰改性的方法及应用前景。     

八角茴香油的实验室提取方法

根据八角茴香油中的主成份是八角茴香脑（约占80％－90％），其精油颜色为无色至淡黄色液体，低温时为白色结晶，mp为22.5℃－23℃，能溶于乙醇，几乎不溶于水，一般采用乙醇回流法或索氏提取法从八角茴香粉末中提取精油。     

中外水利教育的比较研究

从中外水利教育的管理、教学、科研及产学研相结合方面进行了比较研究，并提出了相应的结论和建议。     

呼市自备井生活供水系统水质污染及防治对策

根据对代表性自备井供水单位的水质抽样化验结果及自来水公司供水系统的水质监测数据，对比分析了呼和浩特市自备井生活供水系统的水质污染现状和主要原因，提出了相应的防治对策。     

液-气喷射器在电厂炉烟水处理中的应用研究

本文通过对液－气喷射器的结构及工作原理进行分析，针对呼和浩特市发电厂中50MW容量机组，并提出将该喷射器用于循环冷却水处理系统中，从而有效防止凝汽器铜管表面结垢，不但可以节省费用，减轻环境污染，而且可以提高机组热交换效率，降低煤耗。