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.     

构建现代远程开放教育考试体系初探

现代远程开放教育是基于以学习者为中心的开放学习和个别化学习。我们应从素质教育的培养目标出发 ,依据现代考试测量理论 ,利用现代科技手段 ,建立现代远程开放教育考试体系 ,客观、准确地评价学习者的进步状况以及在学识、能力等方面达到的水平 ,使学习者在学习过程中不断自我完善 ,培养他们积极进取的精神     

基于Delphi的医疗器械商品检索系统设计

分析了采用Delphi6.0编程工具研究并设计的医疗器械商品检索系统，介绍了系统开发的环境特征、数据库应用程序开发步骤及开发过程，包括创建主界面、数据库及编程等，分析了该系统存在的不足及改进措施。     

蛋白组学方法应用于人肺癌组织蛋白表达的研究

采用蛋白组学方法,利用4例中国肺癌患者的切除肺癌组织测定了磷癌(SQCLC)的蛋白表达 从双向电泳(2-DEgel)切下53个点,49个蛋白与数据库搜索结果吻合。在鉴定的24个蛋白中,17个蛋白有报道是与肺癌相关的蛋白其7个蛋白与人类其它癌症相关。所建立的蛋白组学方法能够用于建立一种基于组织的化验方法,发现肺癌患者组织中表达的蛋白标记物以用于癌症的分子学诊断。     

出境旅游市场管理系统的设计及应用

出境旅游业是我国近年来的新产业 ,目前旅游市场管理不规范 ,竞争手段不正常 ,急需一套合理的管理体制。为解决这一问题 ,本文开发了一个出境旅游市场管理系统 ,使用计算机对出境市场信息进行处理 ,以实现管理手段现代化。     

基于ASP技术的Access数据库安全隐患及其对策

针对当前广泛使用的ASP和Access数据库相结合的技术 ,提出了采用此技术的几个常见的安全问题 ,并指出需要采用的一些安全措施     

Web数据库性能调优(英文)

提出了一种基于Web数据库系统设计、实现和性能调优的新方法,该方法包括由RDBMS配置优化、应用模式设计优化和编程优化。通过内存、分段、磁盘参数和时间相关参数的优化可以设置一个好的RDBMS运行环境。在编程时,通过减少与后台连接和断开操作、建立和使用索引、多用存储过程和优化SQL语句可以优化系统性能。在应用设计时,通过优化应用逻辑和降低规范化可以大大地改善系统性能。     

基于校园网的三层结构网络教学平台构建

网络教学平台是实现网络教学的基础。传统的两层结构应用模式具有一定的局限性,采用Web数据库技术和动态网页设计技术构建基于校园网的三层结构网络教学平台,能有效的解决网络传输流量等方面的问题,能更好的在校园网上实现教学资源的共享,提高网络教学的质量。     

Physiologically Based Liver Modeling and Risk Assessment

Because of the inherent complexity of biological systems, there is often a choice between a number of apparently equally applicable physiologically based models to describe uptake and metabolism processes in toxicology or risk assessment. These models may fit the particular data sets of interest equally well, but may give quite different parameter estimates or predictions under different (extrapolated) conditions. Such competing models can be discriminated by a number of methods, including potential refutation by means of strategic experiments, and their ability to suitably incorporate all relevant physiological processes. For illustration, three currently used models for steady-state hepatic elimination--the venous equilibration model, the parallel tube model, and the distributed sinusoidal perfusion model--are reviewed and compared with particular reference to their application in the area of risk assessment. The ability of each of the models to describe and incorporate such physiological processes as protein binding, precursor-metabolite relations and hepatic zones of elimination, capillary recruitment, capillary heterogeneity, and intrahepatic shunting is discussed. Differences between the models in hepatic parameter estimation, extrapolation to different conditions, and interspecies scaling are discussed, and criteria for choosing one model over the others are presented. In this case, the distributed model provides the most general framework for describing physiological processes taking place in the liver, and has so far not been experimentally refuted, as have the other two models. These simpler models may, however, provide useful bounds on parameter estimates and on extrapolations and risk assessments.     

提高Asp动态网页运行效率应注意的几个问题

讨论了在Asp网页设计中影响程序运行效率的主要因素,对由于Asp技术使用不当造成的程序效率降低的原因进行了分析,并提出了具体的改进方法.