• Geomechanics and Engineering
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• 제31권6호
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• pp.637-651
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• 2022

The seismic design of embankment dams requires more comprehensive studies to understand the behaviour of dams. Deformations primarily control this behaviour occur during or after earthquake loading. Dam failures and incidents show that the impacts of deformations should be reviewed for existing and new embankment dams. Overtopping erosion failure can occur if crest deformations exceed the freeboard at the time of the deformations. Therefore, crest settlement is one of the most critical deformations. This study developed empirical formulas using Gene Expression Programming (GEP) based on 88 cases. In the analyses, dam height (H_d), alluvium thickness (H_a), the magnitude-acceleration-factor (MAF) values developed based on earthquake magnitude (Mw) and peak ground acceleration (PGA) within this study have been chosen as variables. Results show that GEP models developed in the paper are remarkably robust and accessible tools to predict earthquake-induced crest settlement of embankment dams and perform superior to the existing formulation. Also, dam engineering professionals can use them practically because the variables of prediction equations are easily accessible after the earthquake.

• 정보처리학회 논문지
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• 제13권5호
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• pp.217-220
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• 2024

지진 발생은 정확히 예측하기 어렵고, 이러한 무작위성을 갖는 사건에 대비하여 모든 건물에 내진 설계를 도입하는 것은 현실적으로 어려운 과제이다. 건물의 특징 분석을 통한 건물 손상 예측을 기반으로 건물의 취약점을 보완한다면, 내진 설계를 도입하지 않은 건물에서도 피해를 최소화할 수 있으므로 건물 손상 예측 모델의 효율성을 분석하는 연구가 필요하다. 본 논문에서는 2015년 네팔 대지진으로 인해 손상된 건물 데이터를 활용하여 Random Forest, Extreme Gradient Boosting, LightGBM, CatBoost 기계학습 분류 알고리즘을 사용하여 지진 피해 예측 모델의 정확도를 비교하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1067-1069
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• 2003

The Earthquake Case Study and Disasters Information System based on GIS (MapECDIS 2002 for Windows), sponsored by Science and Technique Ministry of CHINA, is a GIS system developed to provide a tool for the government and the public to query and comprehend the disaster information (since 2221BC) and case study results (since 1966) of destructive earthquakes occurred in China. The system is expected to be useful for the earthquake forecast practice, the seismology research and earthquake disasters research as an applied assistant tool. The design idea and main functions of the system are introduced in the paper.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.226-229
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• 1999

We have been developing a method to build models for time series using Genetic Programming. The proposed method has been applied to various kinds of time series e.g. computer-generated chaos, natural phenomena, and financial market indices etc. Now we apply the prediction method to time histories of seismic ground motion i.e. one-step-ahead prediction of seismographic amplitude. Waves of earthquakes are composed of P-waves and S-waves. They propagate in different speeds and have different characteristics. It is believed that P-waves arrive firstly and S-waves arrive secondly. Simulations were performed based on real data of Hyuganada earthquake which broke out at southern part of Kyushuu Island in Japan. To our surprise, prediction model built using the earthquake waves in early time can enough precisely predict main huge waves in later time. Lots of experiments lead us to conclude that every slice of data involves P-wave and S-wave. The simulation results suggest the GP-based prediction method can be utilized in alarm systems or dispatch systems in an emergency.

• Structural Engineering and Mechanics
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• 제48권2호
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• pp.151-171
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• 2013

The current paper presents the numerical blind prediction of nonlinear seismic response of two full-scale, three dimensional, one-story reinforced concrete structures subjected to bidirectional earthquake simulations on shaking table. Simulations were carried out at the laboratories of LNEC (Laboratorio Nacional de Engenharia Civil) in Lisbon, Portugal. The study was motivated by participation in the blind prediction contest of shaking table tests, organized by the challenge committee of the 15th World Conference on Earthquake Engineering. The test specimens, geometrically identical, designed for low and high ductility levels, were subjected to subsequent earthquake motions of increasing intensity. Three dimensional nonlinear analytical models were implemented and subjected to the input base motions. Reasonably accurate reproduction of the measured displacement response was obtained through appropriate modeling. The goodness of fit between analytical and measured results depended on the details of the analytical models.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.17-20
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• 2004

The purpose of this study is to arrange the digital maps of Hamamatsu City and to construct the map information system to support the prediction and restoration of Tokai earthquake disasters. The authors arrange the land condition map and compute the populations of each land surface conditions and revealed that $37\%$ of the whole population lives in the safe land, but $63\%$ lives in the rather unsafe surface condition. The authors also arrange the digital map of the main lines of water supply pipe lines in corporation with the Hamamatsu City Water Supply Department and revealed the rather dangerous pipe line area in case of Tokai earthquake.

• Earthquakes and Structures
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• 제6권3호
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• pp.251-266
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• 2014

Dynamic analyses for a suite of ground of motions were conducted on concrete gravity dam sections to examine the earthquake induced stresses and effective damping. For this purpose, frequency domain methods that rigorously incorporate dam-reservoir-foundation interaction and time domain methods with approximate hydrodynamic foundation interaction effects were employed. The maximum principal tensile stresses and their distribution at the dam base, which are important parameters for concrete dam design, were obtained using the frequency domain approach. Prediction equations were proposed for these stresses and their distribution at the dam base. Comparisons of the stress results obtained using frequency and time domain methods revealed that the dam height and ratio of modulus of elasticity of foundation rock to concrete are significant parameters that may influence earthquake induced stresses. A new effective damping prediction equation was proposed in order to estimate earthquake stresses accurately with the approximate time domain approach.

• 한국지진공학회논문집
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• 제27권2호
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• pp.111-118
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• 2023

The 2017 Pohang earthquake afflicted more significant economic losses than the 2016 Gyeongju earthquake, even if these earthquakes had a similar moment magnitude. This phenomenon could be due to local site conditions that amplify ground motions. Local site effects could be estimated from methods using the horizontal-to-vertical spectral ratio, standard spectral ratio, and the generalized inversion technique. Since the generalized inversion method could estimate the site effect effectively, this study modeled the site effects in the Korean peninsula using the generalized inversion technique and the Fourier amplitude spectrum of ground motions. To validate the method, the site effects estimated for seismic stations were tested using recorded ground motions, and a ground motion prediction equation was developed without considering site effects.

• 자원환경지질
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• 제53권3호
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• pp.321-336
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• 2020

일본 지진방재 컨트롤타워는 지진조사연구추진본부이며, 산하의 정책위원회는 국가 종합기본시책과 조사관측계획을 수립하고 지진조사위원회는 각 지진방재 전문기관의 조사관측데이터와 연구성과를 취합하여 종합 검토평가를 한다. 일본의 지진방재·대응 시스템의 벤치마킹을 통한 우리나라에의 바람직한 시사점으로는 지진관련 지오-리질리언스 연구전략 구축이다. 지오-리질리언스 개념은 연구성과 실용화와 지질자원분야의 타 과학기술·인문사회분야와의 융합에 의한 재해복원능력 향상 역량을 의미하며, 주요 범위로는 국가 중장기 로드맵 전략연구, 지진예측연구, 지진재해 예측·경감기술개발, Geo-ICT 융합기술개발, Geo-사이버물리시스템 구현, 지구모방 기술개발 등과 지진발생지역 주민의 물리적, 심리적 치유관련 지질자원기술 관점 연구개발 등이다. 이를 통해, 국책전문연구기관은 재해발생 예측기술개발과 선제적 대응능력 강화, 지오데이터와 연구결과에 대한 지역사회의 신뢰도 제고와 차세대 인력양성, 관련 지진방재 인프라 확충 등이 가능할 것이다.

• 한국지진공학회논문집
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• 제22권3호
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• pp.211-217
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• 2018

The Pohang earthquake with a magnitude of 5.4 occurred on November 15, 2018. The epicenter of this earthquake located in south-east region of the Korean peninsula. Since instrumental recording for earthquake ground motions started in Korea, this earthquake caused the largest economic and life losses among past earthquakes. Korea is located in low-to moderate seismic region, so that strong motion records are very limited. Therefore, ground motions recorded during the Pohang earthquake could have valuable geological and seismological information, which are important inputs for seismic design. In this study, ground motions associated by the 2018 Pohang earthquake are generated using the point source model considering domestic geological parameters (magnitude, hypocentral distance, distance-frequency dependent decay parameter, stress drop) and site amplification calculated from ground motion data at each stations. A contour map for peak ground acceleration is constructed for ground motions generated by the Pohang earthquake using the proposed model.