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1.
近日对我国著名电子光学和光电子成像专家周立伟院士进行了访谈。访谈中,周院士首先分享了自己学习英语和俄语的经历,强调了自主学习能力的重要性;其次,周院士详细论述了外语教学,尤其是英语教学的必要性,指出英语能力与科学研究紧密相关,英语教学不可或缺;之后周院士分析了研究生在英语学习和科学研究方面存在的问题,并讨论了大学中开设人文课程的迫切性;最后,周院士对上理工师生提出了建议与期望。  相似文献   
2.
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.  相似文献   
3.
Environmental scanning is a broadly defined concept, having first received attention from scholars in the late 1960s. Over the years a number of similar and overlapping constructs have emerged in management literature. The aim of this study, via a systematic review and thematic analysis of relevant empirical research, is to consolidate foundation environmental scanning knowledge, demonstrate how scanning research has developed and fragmented over time, and propose an agenda for future research. The first contribution of our review is a new typology of environmental scanning research made up of five discrete research views, which provides a more comprehensive and contemporary overview of the field than previous studies. The second is a proposed agenda for future research that explicitly acknowledges the role of technology, an area that is presently underdeveloped in foundation scanning literature. The third contribution is to signpost future directions for research on scanning and organisational performance using a number of theoretical perspectives. The overall outcome of our review is to move scanning research on from increasingly incremental contributions concerned with context to a place where the changing role of technology and the mechanisms through which environmental scanning contributes to competitive advantage can be more thoroughly understood.  相似文献   
4.
体验式学习的内涵随着时代的发展而逐渐丰富和深化,但无论其如何演变,直接经验和反思始终是体验式学习这一概念的内核。体验式学习理念渗透于美国教育文化之中。具体表现在:小学阶段的教育以学生的真实感知为基础,注重为学生提供真实体验的机会和激发学生的学习兴趣;中学尤其是高中阶段的教育以学生的真实体验为基础,注重为学生提供在新情境中检验所学知识的机会,注重学生知识、技能的内化吸收。美国中小学体验式学习的实施经验可为我国基础教育课程改革提供如下启示:(1)进一步树立和推广体验式学习理念;(2)创设学生进行真实体验的教学环境;(3)注重实施基于学生体验式学习的表现性评价。  相似文献   
5.
This paper proposes a probabilistic frontier regression model for binary type output data in a production process setup. We consider one of the two categories of outputs as ‘selected’ category and the reduction in probability of falling in this category is attributed to the reduction in technical efficiency (TE) of the decision-making unit. An efficiency measure is proposed to determine the deviations of individual units from the probabilistic frontier. Simulation results show that the average estimated TE component is close to its true value. An application of the proposed method to the data related to the Indian public sector banking system is provided where the output variable is the indicator of level of non-performing assets. Individual TE is obtained for each of the banks under consideration. Among the public sector banks, Andhra bank is found to be the most efficient, whereas the United Bank of India is the least.  相似文献   
6.
农村互助型社会养老是具有中国特色的社会养老的发展形式,是对农村传统家庭养老的重要补充。它扎根于农村传统的亲邻互助网络,其本质在于经济互助,表现为有组织地发动邻里、志愿等社会力量,充分利用以老年人为主的各类人力资源的闲置时间、资源低成本地相互帮助和服务。社会各界应将其作为重要实施方略,纳入积极应对人口老龄化战略和乡村振兴战略之中。其发展路径可以概括为:以资金互助为基础,以组织动员为抓手,以服务互助为重点,以社区居家养老为主要阵地,创新各类互助养老模式,着力形成稳定多元的资金来源,培育互助队伍,增加互助内容,从无偿到无偿、低偿相结合,探索建立标准规范的服务管理评估制度,机构养老与社区居家养老互联互通,最终尝试建立圈层化、整合化、网络化、制度化的农村互助型社会养老体系。  相似文献   
7.
国际政治的参与情境决定行动者的博弈行为类型,参与情境变迁将导致行动者行为发生变化。能源安全是国家对外政策的核心议题之一。1973年爆发的第一次石油危机,凸显了能源安全问题的重要性,改变了二战后国际能源政治的参与情境,构建了行动者新的博弈类型,调整了国际能源政治行动者的博弈策略。为了有效应对国际能源政治的情境变迁,美国通过协调与其他国家的能源关系,设置能源安全国际议程,最终确定了新的国际能源秩序。当前,我国在积极参与国际能源合作的过程中,第一次石油危机后国际能源政治的情境变迁以及国际社会的应对策略具有十分重要的启示意义。  相似文献   
8.
Assessment of analytical similarity of tier 1 quality attributes is based on a set of hypotheses that tests the mean difference of reference and test products against a margin adjusted for standard deviation of the reference product. Thus, proper assessment of the biosimilarity hypothesis requires statistical tests that account for the uncertainty associated with the estimations of the mean differences and the standard deviation of the reference product. Recently, a linear reformulation of the biosimilarity hypothesis has been proposed, which facilitates development and implementation of statistical tests. These statistical tests account for the uncertainty in the estimation process of all the unknown parameters. In this paper, we survey methods for constructing confidence intervals for testing the linearized reformulation of the biosimilarity hypothesis and also compare the performance of the methods. We discuss test procedures using confidence intervals to make possible comparison among recently developed methods as well as other previously developed methods that have not been applied for demonstrating analytical similarity. A computer simulation study was conducted to compare the performance of the methods based on the ability to maintain the test size and power, as well as computational complexity. We demonstrate the methods using two example applications. At the end, we make recommendations concerning the use of the methods.  相似文献   
9.
根据支撑基础、责任负担、保障水平以及民众需求等维度,可以把民生保障划分为托底型、基本型、改善型以及富裕型等四种类型。改善型民生是经济社会发展到一定阶段的产物,也是国家治理体系与治理能力现代化的客观要求。它是指通过各类民生项目的安排及民生待遇优化以促进民众生活得到持续改善、社会发展水平得到提升的一种制度类型,是民生项目更加齐全、内容更为完善、治理水平更高、使民众各按其分的民生模式,是人们的日常生活与服务消费支出总额持续增长以便能够提升生活水平的民生类型,是那种不断满足人的需要特别是较高层次需要的模式类型,也是更有助于形成社会结构稳定、国家长治久安的民生制度类型,因而具有综合性、完善性、激励性以及发展性等特点。这要求我们优化民生类型设计及民生投入结构,补齐改善型民生短板,营造良好社会秩序,扎实推进国家治理体系及治理能力现代化建设。  相似文献   
10.
In the presence of rare disasters, risk perceptions may not always align with actual risks. These perceptions can nevertheless influence an individual's willingness to mitigate risks through activities such as purchasing flood insurance. In a survey of Maryland floodplain residents, we find that stated risk perceptions predict voluntary flood insurance take‐up, while perceptions themselves varied widely among surveyed residents, owing in large part to differences in past flood experience. We use a formal test for overoptimism in risk perceptions and find that, on aggregate, floodplain residents are overly optimistic about flood risks.  相似文献   
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