Forecasting earthquakes and earthquake risk

This paper reviews issues, models, and methodologies arising out of the problems of predicting earthquakes and forecasting earthquake risk. The emphasis is on statistical methods which attempt to quantify the probability of an earthquake occurring within specified time, space, and magnitude windows. One recurring theme is that such probabilities are best developed from models which specify a time-varying conditional intensity (conditional probability per unit time, area or volume, and magnitude interval) for every point in the region under study. The paper comprises three introductory sections, and three substantive sections. The former outline the current state of earthquake prediction, earthquakes and their parameters, and the point process background. The latter cover the estimation of background risk, the estimation of time-varying risk, and some specific examples of models and prediction algorithms. The paper concludes with some brief comments on the links between forecasting earthquakes and other forecasting problems.     

地震灾后房屋鉴定

我国是一个地震灾害极其严重和频繁的国家,如汶川、唐山特大地震造成大量建筑物破坏和倒塌,加上由地震引起的火灾、岩石流等次生灾害,造成大量经济损失,对社会也产生了很大影响,因此,地震灾后鉴定工作非常重要。     

消防部队应对地震救援工作的探讨

随着近年来我国地震频发,消防部队在地震中的救援工作越来越繁重。笔者根据汶川、玉树两次地震救援的情况,提出了加强地震灾害救援消防部队应注意的几个问题。     

YouTubers’ networking activities during the 2016 South Korea earthquake

While YouTube has become an important social networking platform for risk and crisis communications, research into its role and use during environmental disasters has not been conducted. The present study investigates how Korean YouTubers reacted during the 2016 Gyeongju earthquakes. Two kinds of data were collected from the most popular YouTube clips on the earthquake (from AfreecaTV and YonHap news): the most frequently used words in the replies to the comments and the networked forums among YouTubers. Findings suggest that YouTube has become a channel for quickly increasing public awareness of crises and for promoting safety strategies. InDegree Centralization is higher in professional videos. Hierarchy measure’s value is one, which means the reply-to network is not two-way. There is sparse close-knittedness in amateur videos. Community clusters emerge in amateur videos over time. The results also reveal that YouTubers on AfreecaTV are more likely to express emotional opinions than their counterparts on YonHap news are.     

中国医科大学新校区图书馆综合楼工程结构设计

中国医科大学新校区图书馆综合楼总建筑面积48870平方米,建筑高度77.35米,是一栋以四层裙房为底盘的双塔楼并在十七至十九层间设有连体的超限高层建筑工程,结构形式为框架-抗震墙结构。采用SATWE软件对结构进行了按规范及地安平结果取值下的小震弹性验算,对连体相连的框架柱及底部加强部位墙肢分别进行了中震和大震下的性能目标计算分析,得出了可靠的结论和设计依据。     

Analyzing Transportation Reconstruction Network Strategies: A Full Cost Approach

Policymakers interested in evaluating the costs and benefits of earthquake retrofit and reconstruction strategies require a way to measure the benefits (costs avoided) of competing proposals. This requires an integrated, operational model of losses due to earthquake impacts on transportation and industrial capacity, and how these losses affect the metropolitan economy. Our approach to this problem advances the information provided by transportation and activity system analysis techniques in ways that help capture the most important economic implications of earthquakes. These full cost results have four dimensions: structure damage, business interruption, network performance, and infrastructure damage. Preliminary results for all four measures are summarized for a hypothetical magnitude 7.1 earthquake on the Elysian Park blind thrust fault in Los Angeles.     

Multivariate approach to evaluate the relationship among geophysical and geochemical variables during an unrest period at Campi Flegrei caldera (Italy)

Campi Flegrei is a caldera in Southern Italy, which has manifested signs of significant unrest in the last years. Indeed, during volcanic crises, the ground of Campi Flegrei caldera begin to grow steadily, the earthquake swarms become more common and strong variations in the chemical composition of fumaroles are observed. In the Campi Flegrei volcanic area there is a spread ground deformation monitoring network. In the years 1983–1985 the bradiseism showed an increasing trend of ground uplift with a fairly fast velocity. In the following years (1986–2014) the phenomenon tends to decrease: the earthquakes number is near to zero, the vertical ground displacement decreases, the fumaroles modify the gas emissions, the soil temperature decreases. The main object of this study is to evaluate, by means of variables comparison, in a counterclockwise periods, the relationship among geochemical data of fumaroles, earthquakes and ground deformations, to discover which variables can be considered signals (geochemical indicator) of the bradyseismic events during an unrest period.

     

International stock exchange listing and the reduction of political risk

The impending 1997 assimilation into the People's Republic of China made the 1980s a challenging period for Hong Kong, one in which Kong Kong-based companies relocated their corporate domiciles to other countries as political insurance. International listing, however, is another way for companies to reduce political risk. This paper examines the post-1985 effects of Hong Kong-based company stocks being quoted on London's International Stock Exchange. We document that there is no price effect for these companies after the first trading day and a significant increase in the average trading volume surrounding the event day. This may be attributed to the London market makers who build up their stakes before the listing and who unwind their positions in the Hong Kong market after the event day. We also find that there is, on average, a decrease in systematic risk of these companies after being traded on the London market. Furthermore, the evidence shows that there is an increase in systematic risk for companies that are not listed in London after 4 June 1989, however, not for those London-listed Hong Kong companies. The results constitute evidence to support the inference that there is a reduction of local political risk for internationally listed companies.     

The Effect of Arthur Andersen's Demise on Clients' Audit Fees and Auditor Conservatism: International Evidence

Using samples from 12 non‐U.S.A. countries, we find that following Arthur Andersen's failure in the United States of America, successor Big‐N auditors charged an audit fee premium for ex‐Andersen clients compared to existing clients and non‐Andersen switch‐ins. We show that this audit fee premium is not attributable to the Andersen switch‐ins having lower prior earnings quality or lower bargaining power than non‐Andersen switch‐ins. We also show that ex‐Andersen clients exhibit higher earnings quality after the switch than do ongoing clients and other switch‐ins. These results suggest that the audit fee premium is attributable to auditor conservatism. Furthermore, we find that risk assessments for ex‐Andersen clients are higher in countries with weak legal and extra‐legal institutions. We interpret this result as suggesting that the effect of lost auditor reputation is stronger when objective evidence of earnings quality is uncertain because of weaker supporting institutions. This is the first study to document a direct effect of countrywide institutions on audit risk assessment.     

震后重建为契机的城市政策转型:墨西哥城案例的启示

1985墨西哥城发生8.1级地震,是世界上为数不多的发生在国家首都的中心地区、并使人口和公共设施都受到严重损害的地震。地震发生时墨西哥正处于快速城市化和经济衰退时期、正要推出一系列改革的起步阶段,面对如此巨大的损失,震后重建的政策调整显得尤为关键。以首都重建为契机,墨西哥政府开始关注城市宏观发展策略、可负担性住房和法规健全等问题,并且通过一系列震后改革策略来推进城市管治思路的转型。事实上,这些震后推出的新政策对城市发展产生了深远的影响:城市中心职能外迁促进了城市功能的有机疏散;以低收入住房为主的住房政策推动了城市的郊区化,同时也使城市中心区住房产权发生了本质性转变;从立法角度对城市进行灾害危险性分区,并对建筑单体构造性能进行严格规定。同样发生在发展中国家高速城市化时期的灾害,墨西哥震后重建的经验和教训将对中国城市防灾抗灾提供重要的借鉴意义。     

Buyer perceptions of supply disruption risk: A behavioral view and empirical assessment

As supply chains become more complex, firms face increasing risks of supply disruptions. The process through which buyers make decisions in the face of these risks, however, has not been explored. Despite research highlighting the importance of behavioral approaches to risk, there is limited research that applies these views of risk in the supply chain literature. This paper addresses this gap by drawing on behavioral risk theory to investigate the causal relationships amongst situation, representations of risk, and decision-making within the purchasing domain. We operationalize and explore the relationship between three representations of supply disruption risk: magnitude of supply disruption, probability of supply disruption, and overall supply disruption risk. Additionally, we draw on exchange theories to identify product and market factors that impact buyers’ perceptions of the probability and magnitude of supply disruption. Finally, we look at how representations of risk affect the decision to seek alternative sources of supply. We test our model using data collected from 223 purchasing managers and buyers of direct materials. Our results show that both the probability and the magnitude of supply disruption are important to buyers’ overall perceptions of supply disruption risk. We also find that product and market situational factors impact perceptions of risk, but they are best understood through their impact on perceptions of probability and magnitude. Finally, we find that decisions are based on assessments of overall risk. These findings provide insight into the decision-making process and show that all three representations of risk are necessary for fully understanding risky decision-making with respect to supply disruptions.     

改进主成分分析方法及其在地震数据处理中的应用

本文基于地震数据的特征,引入向量成分化概念,提出了一种改进的PCA方法,并给出了相应的算法实现。应用改进后的PCA方法,分析了西安高陵2009年11月5日地震的前兆数据以及之前发生在西安地区的多次地震的前兆数据。分析结果表明:这种改进的PCA方法在处理地震数据时,主成分数据拟合曲线的震前特征更便于数学表示,为地震的分析和预测提供了良好的基础。     

由近年我国地震频发看建筑结构的抗震设计

近年来我国地震频发,强烈的地震经常造成人身伤亡和财产的巨大损失。所以,建筑结构的抗震设计也越来越受人们所关注。本文主要以现代建筑结构设计的一些体会,对抗震设计问题进行了研究和分析。     

地震气象机理及预测方法探索——关于意大利6级地震的预测实践和分析

最近发表的几份研究报告表明,半平稳线性云层可能是地震的起因。通过对4年卫星图像的检查,我们发现了意大利上空的线性云层形成的许多例子。一个简单的测试表明,这些云层的形成与意大利及其周围地区发生的地震之间没有明显的统计关系。我们在卫星图像中已经识别出的所有线性云层,似乎都是地形的-由山上流满水的风的相互作用形成。     

桥梁结构的震害及抗震设计方法浅析

桥梁是"生命线工程的"重要组成部分,通过对国内外地震灾害的研究表明,震区桥梁的损坏坍塌,不仅会阻碍救灾行动,而且影响灾后的重建工作。因此,对于那些震后的紧急救援和震后经济恢复中具有重要地位的桥梁,要求比较严格,应不发生震害或震后可快速恢复后即可使用,本文将针对桥梁结构的震害及抗震设计方法进行探讨。     

Does rising income increase or decrease damage risk from natural disasters?

Recent empirical literature has found a negative relationship between income per capita and measures of risk from natural disaster, supportive of logic that higher incomes allow countries to mitigate disaster risk. We argue that behavioral changes at the micro level in response to increasing income (such as location choice and extent of costly abatement activity) may lead to a non-linear relationship between aggregate incomes and disaster damages, where the risks increase with income before they decrease. In a country-year panel data set, we show that disaster risk associated with flooding, landslides and windstorms increases with income up to GDP per capita levels of $5044, $3360, and $4688 per year respectively and decrease thereafter. Such non-linear impacts are absent for other disaster types such as extreme temperature events and earthquakes where the links between human behavioral choices and exposure to risk are not as strong. From a policy perspective, this suggests that for the least developed countries, the dual goals of disaster risk prevention and economic development cannot be assumed to be complementary for all forms of natural disaster. In addition to allocating resources to manage disaster risk, the poorest nations may have to be more proactive in enacting policies that alter the behavioral choices of citizens that impact a country's exposure to natural disaster risk.     

刚度不均匀分布的连体结构的抗震性能分析

通过连接体将两个或两个以上的独立塔楼连接在一起,形成连体结构。在地震作用下,塔楼的变形和内力变化复杂,且两塔楼之间的耦联效果显著。本文采用弹塑性时程分析法,研究其在罕遇地震作用下的动力响应,并且通过对不同对称性、平面内不同刚度分布、不同跨度的结构进行弹塑性时程分析,分析结构的对称性、跨度的参数对结构动力响应的影响。     

关于现代建筑结构的抗震加固技术探讨

为减少地震对建筑的破坏,对未进行抗震设防或已进行抗震设防但达不到设防标准的建筑进行加固,可使建筑物在遇到强烈地震时不受较大的影响,避免人员伤亡与财产损失。本文通过分析我国建筑抗震技术的发展现状,针对2008版抗震规范修订内容及抗震加固技术进行探讨,以期通过本文的阐述不断完善设计理论,并有效通过加强施工质量管理来提高建筑物的抗震性能。     

基于灰色关联度的社区抗震韧性评价研究

我国对于社区抗震韧性的研究起步较晚,通过研究现有文献,发现国内学界关于地震建筑物应急疏散评价的研究较少,且以层次分析和模糊评价为主,方法单一.本文通过查阅40多篇国内外文献中涉及的151个评价指标,通过专家调研进行预分类,从社区抗损害性,社区疏散能力,社区环境承载能力三个方面构建社区抗震韧性的评价指标体系;利用熵权法权...