• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.821-831
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• 2019

The 9.12 earthquake (2016.9.12., M_L=5.8) and Pohang (2017.11.15., M_L=5.4) caused social and economic damage, resulting in a greater public interest in earthquakes than in the past. In the U.S., Japan and Chile, which have high frequency of earthquakes, infrastructure facilities are already managed based on probabilistic seismic hazard analysis (PSHA) and ground motion prediction equation (GMPE) to prepare for and respond to seismic disasters. In South Korea, the aforementioned PSHA and GMPE models have been developed independently through individual researchers. However, the limited disclosure of basic data, calculation methods, and final results created during the model development poses a problem of deploying new data without updating the earthquake that occurs every year. Therefore, this paper describes how to create flatfile, which is the basic data of GMPE, and how to process for seismic waves, and how to create intensity measures.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.1
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• pp.1-8
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• 1999

Dynamic elastoplastic LPM (lumped parameter mass) analyses are carried out in order to investigate the seismic resistant performance of a typical high-rise shear wall apartment subjected to several earthquakes. Three-dimensional nonlinear pushover analysis is adopted to estimate initial elastic stiffness, yielding strength and post-yielding stiffness of each story for the time history analysis of LPM shear model. For the hysteresis of each story, Clough and bilinear models are used with the input of four recorded earthquake ground motions of EI Centro 1940 NS, Taft 1952 EW, Hachinohe 1968 NS and Kobe 1995 NS, of which the amplitudes are scaled down to have the same maximum ground velocity of 12 kine. The result shows that yieldings take place in most storys of the building, i.e. the earthquake resistant capacity of this high-rise shear wall apartment is not sufficient at the event of earthquake M=5~6.

• Journal of Korean Society of Steel Construction
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• v.19 no.5
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• pp.435-454
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• 2007

In this study, we demonstrated the characteristics of the near-fault ground motion thatwas not considered in the domestic seismic design code and how the effect of the near-fault ground motion affects the response of cable-stayed bridges. Afterselecting the actual measurement records of the typical near- and far-fault ground motion, the characteristics of ground motion is analyzed using the elastic and inelastic response spectrum. Analyzing the response regarding the earthquake's characteristics on cable-stayed bridges by the typical three-type cable-stayed bridges and the actual cable-stayed bridge, the characteristics of responses about main members are compared and analyzed. Moreover,reliability analysis is accomplished using the results of the seismic response analysis, and the seismic safety of the cable-stayed bridges is evaluated quantitatively as a reliability index and probability of failure. According to the results of the response spectrum, the earthquake response analysis and the reliability analysis, because the effect of the near fault ground motion against the response of cable-stayed bridges is different from the effect of the existing far-fault ground motion, it should be considered as an important factor when designing cable-stayed bridges.

• Journal of the Korean earth science society
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• v.39 no.6
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• pp.593-599
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• 2018

The onset times of P- and S-waves are important information to have reliable earthquake locations, 1D or 3D subsurface velocity structures, and other related studies in seismology. As the number of seismic stations increases significantly in recent years, it becomes a formidable task for network operators to pick phase arrivals manually. This study used a simple method to estimate additional P- and S-wave arrival times for local earthquakes when a priori information (event location and time) is available using the Akaike Information Criterion (AIC). We applied the AIC program to the earthquake data recorded at the seismic station located in Gyeongsan (DAG2). The comparisons of automatically estimated phase arrival times with manually picked onset times showed that 95.1% and 93.7% of P-wave and S-wave arrival time estimations, respectively, are less than 0.1 second difference. The higher percentage of agreement presented the method which can be successfully applied to large data sets recorded by high-density seismic arrays.

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.117-125
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• 2009

In this paper, an integrated management system of seismic observatory information based on XML is proposed. The number of organizations which have their own seismic stations eg. KMA, KIGAM etc is increasing since 1998. Related informations such as location, installed instruments. and operational profile are essential for efficient utilization of seismic data. It's not easy to provide the uniform type of information and has limitation to announce the updated information of station rapidly through individual information management system of each organization. In this paper, we propose an integrated management system of seismic observatory information which can support to manage information of their own seismic observatory by a person in charge via Web, to integrate that in nation-wide and to provide that for users. We investigated minimum information of observatory were needed to use seismic data and the analysis result was structured by using XML. The integrated management system consists of the observatory management module. information search module, and the latest information supply module etc. By using proposed system, seismic observatory information of each organization can be managed and be supplied efficiently in nation-wide.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.73-79
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• 2008

Economic growth, industrialization and urbanization have made society more vulnerable than ever to seismic hazard in Korea. Although Korea has not experienced severe damage due to earthquakes during the last few decades, there is little doubt of the potential for large earthquakes in Korea as documented in the historical literature. As we see no immediate promise of short-term earthquake prediction with current science and technology, earthquake early warning systems attract more and more attention as a practical measure to mitigate damage from earthquakes. Earthquake early warning systems provide a few seconds to tens of seconds of warning time before the onset of strong ground shaking. To achieve rapid earthquake location, we propose to take full advantage of information from existing seismic networks; by using P wave arrival times at two nearest stations from the earthquake hypocenter and also information that P waves have not yet arrived at other stations. Ten earthquakes in the Korean peninsula and its vicinity are selected for the feasibility study. We observed that location results are not reliable when earthquakes occur outside of the seismic network. Earthquakes inside the seismic network, however, can be located very rapidly for the purpose of earthquake early warning. Seoul metropolitan area may secure $10{\sim}50$ seconds of warning time before any strong shaking starts for certain events. Carefully orchestrated actions during the given warning time should be able to reduce hazard and mitigate damages due to potentially disastrous earthquakes.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.187-197
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• 2010

The paleoseismological study in Korea has begun along the Yangsan fault zone (YFZ) and Ulsan fault zone (UFZ) since 1994. Some evidences related to late Quaternary movement are found at only some part of the YFZ, such as Pyonghae, Yuge, and Eonyang-Tongdosa areas. However, it is found along the most of the UFZ except the northen and southern ends of the fault. The dominant time span of faulting events along the YFZ and UFZ are quite different, and 500 ka to 200 ka and 300 ka to recent time, respectively. The dominant faulting senses of the YFZ and UFZ are right-lateral strike slip and reverse, respectively. These senses correspond well with the focal mechanism of recent occurring earthquakes along these two fault zones. If we evaluate the intensity of the activity of the YFZ from the average slip rate, which is 0.1~0.04 m/ka, it is comparable with the faults of higher C class in Japan. The slip rate of UFZ, which is 0.2~0.06 m/ka, is comparable with the faults of lower B to higher C class. Based on the relationship between maximum displacement and magnitude, the maximum earthquake magnitude is evaluated to be 6.8 and 7.0 in the YFZ and UFZ, respectively. An intensive studies are needed to clarify the problems such as segmentation of faults, return period, and geological evidences related to historical earthquakes.

• Cement
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• s.194
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• pp.38-43
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• 2012

2012년 일본 시멘트 내수는 공공부문의 지진 복구 수요 본격화와 함께 민간부문의 수요증가에 따라 전년대비 2.7% 증가한 4,303만톤을 기록하며 2년 연속 증가할 것으로 예상된다. 수출의 경우 공공부문과 민간 내수의 증가로 수출여력이 감소해 전년대비 8.2% 감소한 9,22만톤을 기록할 것으로 예상된다. 반면 수입은 공공부문과 민간부문 모두 확대가 예상되지만 수출 감소가 생산 증가효과를 일부 상쇄하여 전년대비 1.0% 증가한 5,769만톤에 머물 것으로 예상되는 가운데 그 증가 폭은 제한적일 것으로 보인다. 여기서는 일본의 미즈호종합연구소가 내놓은'2012년도 일본산업동향(시멘트)'보고서를 통해 일본 시멘트산업의 수급동향 및 향후 전망에 대해 살펴본다.

• The Journal of Engineering Geology
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• v.5 no.1
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• pp.59-74
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• 1995

It is well known that the hypocentral parameters inside the seismic array are well determined using HYPO71PC Programs. These programs, however, do not woik well for the non-evenly distribution of the seismic stations and/or the seismic events outside the seismic array. Furthermore it is very difficult to determine the exact locations of small events in North Korea since there is no seismological data exchange between South and North Koreas. We used the polarization method of the single-station with 3-component in addition to HYPO71PC(IASPEI's Program) in order to determine the source parameters of shallow-focus earthquakes outside the seismic array. First of all, we tested the interior events of the Uisung earthquake, April 14, 1991 and the Mt. Keyryong earthquakes, Feorirary 12, 1994, and two exterior events of W. Pyoungyang earthquake, Noventer 12, 1992, and Yellow Sea earthquake, July 26, 1994 to investigate the convergence and divergence to calculate the source parameters. We have found that the source determination outside the seismic array never converges to the exact location whereas the any events inside the array quickly converge to the exact location. The seismic events outside the array such as two events Vladivostok and East Sea, and the Yellow Sea event are more accurately determined using the polarization method. Estimating the source azimuth is carried out by estimating the polarization direction of the interesting phases and the range estimate is made frum the relative timing of different phases. The polarization method is verified by fmding that the estimates of azimuths and incidence angles by the polarization method are identical with those of the synthetic seismograms of the modellings using the generator program.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.3
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• pp.53-62
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• 2002

Site soil condition affects significantly on the seismic response of a structure and is a critical factor for the performance based seismic design of a structure. In this paper, the effects of nonlinear soil properties on the elastic response spectra of a structure including the nonlinearity of a soil due to the earthquake excitation is investigated using one step finite element approach for the entire soil structure system and approximate linear iterative procedure to simulate the nonlinear soil behavior with the Ramberg-Osgood soil model. Studies were carried out for a linear SDOF system of a variable period with and without a pile group for the 1940 CI Centro earthquake recorded on ground rather than rock. The study results showed clearly that the effect of the nonlinear behavior of soft soil is very important on the elastic seismic response of a structure suggesting the necessity of the performance based seismic design.