Seismic vulnerability assessment and mapping using frequency ratio and logistic regression: a case study of Gyeongju, South Korea

2019 ◽  
Author(s):  
Jihye Han ◽  
Soyoung Park ◽  
Seongheon Kim ◽  
Sanghun Son ◽  
Seonghyeok Lee ◽  
...  
Keyword(s):  
Logistic Regression ◽  
South Korea ◽  
Vulnerability Assessment ◽  
Frequency Ratio ◽  
Seismic Vulnerability ◽  
Seismic Vulnerability Assessment

scholarly journals Performance of Logistic Regression and Support Vector Machines for Seismic Vulnerability Assessment and Mapping: A Case Study of the 12 September 2016 ML5.8 Gyeongju Earthquake, South Korea

2019 ◽  
Vol 11 (24) ◽  
pp. 7038 ◽  
Author(s):  
Jihye Han ◽  
Soyoung Park ◽  
Seongheon Kim ◽  
Sanghun Son ◽  
Seonghyeok Lee ◽  
...  
Keyword(s):  
Logistic Regression ◽  
South Korea ◽  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Spatial Databases ◽  
Support Vector ◽  
Seismic Vulnerability Assessment ◽  
The Common ◽  
Gyeongju Earthquake

In this study, we performed seismic vulnerability assessment and mapping of the ML5.8 Gyeongju Earthquake in Gyeongju, South Korea, as a case study. We applied logistic regression (LR) and four kernel models based on the support vector machine (SVM) learning method to derive suitable models for assessing seismic vulnerabilities; the results of each model were then mapped and evaluated. Dependent variables were quantified using buildings damaged in the 9.12 Gyeongju Earthquake, and independent variables were constructed and used as spatial databases by selecting 15 sub-indicators related to earthquakes. Success and prediction rates were calculated using receiver operating characteristic (ROC) curves. The success rates of the models (LR, SVM models based on linear, polynomial, radial basis function, and sigmoid kernels) were 0.652, 0.649, 0.842, 0.998, and 0.630, respectively, and the prediction rates were 0.714, 0.651, 0.804, 0.919, and 0.629, respectively. Among the five models, RBF-SVM showed the highest performance. Seismic vulnerability maps were created for each of the five models and were graded as safe, low, moderate, high, or very high. Finally, we examined the distribution of building classes among the 23 administrative districts of Gyeongju. The common vulnerable regions among all five maps were Jungbu-dong and Hwangnam-dong, and the common safe region among all five maps was Gangdong-myeon.

scholarly journals Seismic Vulnerability Assessment and Mapping of Gyeongju, South Korea Using Frequency Ratio, Decision Tree, and Random Forest

2020 ◽  
Vol 12 (18) ◽  
pp. 7787 ◽  
Author(s):  
Jihye Han ◽  
Jinsoo Kim ◽  
Soyoung Park ◽  
Sanghun Son ◽  
Minji Ryu
Keyword(s):  
Random Forest ◽  
Decision Tree ◽  
South Korea ◽  
Vulnerability Assessment ◽  
Seismic Data ◽  
Frequency Ratio ◽  
Seismic Vulnerability ◽  
Success Rates ◽  
Ground Acceleration ◽  
Seismic Vulnerability Assessment

The main purpose of this study was to compare the prediction accuracies of various seismic vulnerability assessment and mapping methods. We applied the frequency ratio (FR), decision tree (DT), and random forest (RF) methods to seismic data for Gyeongju, South Korea. A magnitude 5.8 earthquake occurred in Gyeongju on 12 September 2016. Buildings damaged during the earthquake were used as dependent variables, and 18 sub-indicators related to seismic vulnerability were used as independent variables. Seismic data were used to construct a model for each method, and the models’ results and prediction accuracies were validated using receiver operating characteristic (ROC) curves. The success rates of the FR, DT, and RF models were 0.661, 0.899, and 1.000, and their prediction rates were 0.655, 0.851, and 0.949, respectively. The importance of each indicator was determined, and the peak ground acceleration (PGA) and distance to epicenter were found to have the greatest impact on seismic vulnerability in the DT and RF models. The constructed models were applied to all buildings in Gyeongju to derive prediction values, which were then normalized to between 0 and 1, and then divided into five classes at equal intervals to create seismic vulnerability maps. An analysis of the class distribution of building damage in each of the 23 administrative districts showed that district 15 (Wolseong) was the most vulnerable area and districts 2 (Gangdong), 18 (Yangbuk), and 23 (Yangnam) were the safest areas.

Seismic vulnerability assessment of historical urban centres: case study of the old city centre in Seixal, Portugal

2013 ◽  
Vol 11 (5) ◽  
pp. 1753-1773 ◽  
Author(s):  
Tiago Miguel Ferreira ◽  
Romeu Vicente ◽  
J. A. R. Mendes da Silva ◽  
Humberto Varum ◽  
Aníbal Costa
Keyword(s):  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
City Centre ◽  
Seismic Vulnerability Assessment ◽  
Old City

scholarly journals Seismic Vulnerability Assessment of Existing Italian Hospitals: The Case Study of the National Cancer Institute “G. Pascale Foundation” of Naples

2021 ◽  
Vol 15 (1) ◽  
pp. 182-202
Author(s):  
Mattia Zizi ◽  
Pasquale Bencivenga ◽  
Gennaro Di Lauro ◽  
Gianfranco Laezza ◽  
Pasquale Crisci ◽  
...  
Keyword(s):  
Vulnerability Assessment ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Site Investigation ◽  
Assessment Process ◽  
Past Century ◽  
Structural Elements ◽  
Original Design ◽  
Seismic Vulnerability Assessment

Introduction: A large portion of the Italian built heritage is characterized by a significant seismic vulnerability since many structures were designed with outdated criteria, i.e., without accounting for seismic actions. This aspect is particularly relevant for strategic structures and infrastructures, whose functionalities are crucial in case of seismic events. Objective: The main aim of the present paper is to share the key findings related to the seismic vulnerability assessment of the National Institute for the Study and Treatment of Cancer (IRCCS) “Giovanni Pascale Foundation” in Naples. In particular, the main evidences could be easily extended to existing hospitals realized in the last century, with the main reference to: construction techniques, quality of constructional material, overt and convert seismic vulnerabilities and possible intervention strategies for risk mitigation. Methods: In the present paper, the assessment methodologies adopted for such a strategic hospital complex are provided, focusing in particular on: i. preliminary research of original design documents and on-site investigation for determining constructional details; ii. material tests on structural elements; iii. vulnerability seismic assessment by means of non-linear FE analyses (push-over and capacity spectrum method); iv. recommendations on retrofitting measures and cost estimations. Results: The conducted study puts into clear evidence the inadequacy of the investigated buildings to face the design seismic actions provided by the current Italian code and thus showed the significant seismic vulnerabilities affecting the Institute “G. Pascale Foundation” of Naples. Among these, particular attention has also been focused on the so-called intrinsic vulnerabilities, namely the ones not measurable explicitly and interesting non-structural elements (e.g., connection of shelves, stained glass windows, facilities, etc.). Conclusion: The presented case study highlights the strong seismic vulnerability affecting structures realized in the past century, despite their strategic functions. On the whole, the examined structures can be considered as representative of this building typology, and the adopted calculation criteria, as well as the assumptions of the assessment process, could be easily extended to similar case studies.

Sign in / Sign up

Export Citation Format

Share Document