• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.64-68
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• 2007

The classic graphical method to determine the epicenter uses differences between the arrival times of P and S waves at each station. In this research, a robust approach is proposed, which provides a fast and intuitive estimation of earthquake epicenters. This method uses an empirical relationship between epicentral distance and traveltime of the first arrival P phase of local or regional earthquake. The relationship enables us to estimate epicentral distances and draw epicentral circles from each station with P-traveltimes counted from a probable origin time. As the assigned time is getting close to the origin time of the earthquake, epicentral circles begin to intersect each other at a possible location of the epicenter. Then the possibility of the epicenter can be expressed by a function of the time and the space. We choose the location which gives the minimum standard deviation of the origin time as an estimated epicenter. In this research, 918 P arrival times from 84 events occurring from 2005 to 2006 listed in the KMA earthquake catalog are used to determine the empirical P-traveltime function of epicentral distances.

• 한국실내디자인학회논문집
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• 제25권1호
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• pp.47-55
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• 2016

This article explores an extended sense of autonomy in contemporary architecture activated through the practice of fashion, by taking architect Rem Koolhaas' work Prada Epicenter in New York as a case. In doing so, it argues that throughout the work Koolhaas sets up a world in which the corporate and the individual are entangled together in complex ways. Instead of considering Prada Epicenter to be the exemplar illustrating that the global company-Prada-institutionalizes the designed commercial space in a top-down manner, this article claims that such a space imbricates a multiplicity of meaning that is generated at the intersections of the local and the global, the ordinary and the spectacular, and the individual and the institutional. In this respect French philosopher Gilles Lipovetsky's fashion theory works as a critical point: his claim that the ambivalence of fashion-both as corporate power and individual freedom-is a threshold encouraging us to better understand the operativity of late capitalism in daily life is extended to Koolhaas' case. In other words, Koolhaas' Prada Epicenter brings forth possibilities that the ostensibly technocratic and institutionalized space in fact works as a resillient field where senses of individual autonomy arise in the aid of corporative practice of branding.

• Earthquakes and Structures
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• 제18권2호
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• pp.201-213
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• 2020

Seismic damages that occurred by the effects of epicenter distance of the earthquake are one of the most important problems for the earthquake engineering. In this study, it is aimed to examine the nonlinear seismic behaviors of concrete gravity (CG) dams considering various epicenter distances. For this purpose, Boyabat CG dam that is one of the biggest concrete gravity dams in Turkey is selected as a numerical application. FLAC3D software based on finite difference method is used for modelling and analyzing of the dam. Drucker-Prager nonlinear material model is used for the concrete body and Mohr-Coulomb nonlinear material model is taken into account for the foundation. Special interface elements are used between dam body and foundation to represent interaction condition. Free-field and quiet non-reflecting boundary conditions are utilized for the main surfaces of 3D model. Total 5 various epicenter distances of 1989 Loma Prieta earthquake are considered in 3D earthquake analyses and these distances are 5 km, 11 km, 24 km, 85 km and 93 km, respectively. According to 3D seismic results, x-y-z displacements, principal stresses and shear strain failures of the dam are evaluated in detail. It is clearly seen from this study that the nonlinear seismic behaviors of the CG dams change depending to epicenter distance of the earthquake. Thus, it is clearly recommended in this study that when a CG dam is modelled or analyzed, distance of the earthquake fault to the dam should be strongly examined in detail. Otherwise, earthquake damages can be occurred in the concrete dam body by the effects of seismic loads.

• 지구물리와물리탐사
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• 제20권1호
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• pp.1-11
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• 2017

P파 및 S파의 초동주시를 활용한 역산기법들을 통해 미소지진 모니터링의 진원위치의 정확도를 향상시키기 위해 시추공 3성분 수진기를 이용한 현장실험이 수행되었다. 3성분 수진기의 수평 $\times$ 성분을 자북방향으로 정렬시키고 중추낙하형 발생원을 이용한 실험을 통해 계측자료의 P파 초동의 입자움직임으로부터 진원의 방향을 추정할 수 있었다. 한편 계측자료에서 S파의 식별이 어려운 경우에도 편극필터의 적용으로 S파의 초동주시를 발췌할 수 있었다. P파 초동주시만을 이용한 역산기법은 진원위치에 대한 초기치가 진원으로부터 크게 이격되면 국부적인 최소값으로 수렴하여 정해를 찾지 못하는 경우가 있다. 본 연구에서는 이러한 문제를 해결하기 위해 P파와 S파의 초동주시 차이를 이용한 진원위치 결정방법과 P파 초동주시만을 이용한 역산을 복합적으로 사용한 결과 진원위치의 정확도를 향상시킬 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.9-11
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• 2021

현재 우리나라는 층간소음 발생 추이가 점차 증가하고 있으며, 이로 인한 2차 갈등의 문제가 증가하고 있다. 이러한 문제점을 해결하기 위해 다양한 연구들이 진행되어 왔으나 층간소음 실험에 대한 정의가 명확하지 않고, 다양한 상황에서의 층간소음 데이터를 획득할 수 없다. 따라서 이 논문에서는 층간소음 진원지 인지 시스템을 위한 다양한 층간소음 실험 시나리오를 정의한다. 이를 위해 실험에 필요한 환경과 실생활에서 발생하는 층간소음 유형 및 수집기의 위치, 소음 강도를 고려하여 실험 시나리오를 정의한다. 정의한 실험 시나리오 기반으로 데이터 수집 및 학습 연산을 수행할 경우, 층간소음 인지 시스템의 정확도를 높일 수 있다.

• 한국컴퓨터정보학회논문지
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• 제13권6호
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• pp.59-68
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• 2008

본 논문에서는 지진 기록계에 할당된 우선순위에 따라 가장 먼저 수신되는 이벤트 패킷으로부터 실제 지진과 연관된 패킷만을 추출하여 진앙을 추정하는 기법을 제안한다. 각 관측소의 지진 기록계로부터 수신된 이벤트 패킷의 신호 시간, 신호 주기 및 SNR 등을 통계적 방법으로 평가하여 실제 지진의 P파와 연관된 패킷을 추출한다. 그리고 초동 P파의 도달시간을 이용한 진앙 추정기법을 이용하여 P파와 연관된 패킷으로부터 진앙을 추정하였다. 2007년 기상청에서 발표한 국내 지진에 대하여 해당 일자의 이벤트 패킷을 이용하여 본 논문에서 제안한 P파 연관 패킷의 추출과 진앙을 추정하였다. 지진 감지 네트워크 내에서 발생한 지진의 경우 4개 이상의 관측소로부터 이벤트 패킷이 도착한 후에 매우 작은 오차 범위 내에서 진앙이 결정되는 것으로 확인되었다. 각 관측소간의 평균거리를 감안하여 타 관측기관의 이벤트 패킷을 이용할 경우에 더욱 빠른 진앙 결정과 지진경보 발령이 가능한 것으로 검증되었다. 따라서 본 연구의 결과는 국내 지진 조기 경보체계의 구축에 효율적으로 이용될 수 있을 것으로 판단된다.

• 대한건축학회논문집:계획계
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• 제34권2호
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• pp.33-40
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• 2018

The purpose of this study was to analyze integration of the surface of Prada Aoyama Epicenter by Herzog & de Meuron. To understand various aspects of surfaces & constituents related, each elevations are analyzed minutely by distance both inside and outside. The results of this study were as follows; the individual surface of Prada Aoyama Epicenter sets a multi-layered relationship with the actual environment. Their architectural surface still has a significance in presenting a way of creating a building along with everyday surroundings.

• Earthquakes and Structures
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• 제5권3호
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• pp.297-319
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• 2013

Two destructive earthquakes occurred on October 23 and November 9, 2011 in Van province of Turkey. The damage in residential units shows significant deviation from the expectation of decreasing damage with increasing distance to epicenter. The most damaged settlement Ercis has the same distance to the epicenter with Muradiye, where no damage occurred while relatively less damage observed in Van having half distance. These three cities seem to have resembling soil conditions. If the damages are evaluated: joint failures and insufficient lap splice lengths are observed to be the main causes of the total collapses in RC buildings. Additionally, low concrete strength, reinforcement detailing mistakes, soft story, heavy overhang, pounding and short columns are among other damage reasons. Examples of damages due to non-structural elements are also given. Remarkable points about seismic damages are: collapsed buildings with shear-walls, heavily damaged buildings despite adequate concrete strength due to detailing mistakes, undamaged two-story adobe buildings close to totally collapsed RC ones and undamaged structural system in buildings with heavily damaged non-structural elements. On the contrary of the common belief that buildings with shear-walls are immune to total collapse among civil engineers, collapse of Gedikbulak primary school is a noteworthy example.

• Geomechanics and Engineering
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• 제13권3호
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• pp.411-429
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• 2017

A Spectral Element Method for 3D seismic wave propagation simulation is derived based on the three-dimensional fluctuating elastic dynamic equation. Considering the 3D real terrain and the attenuation characteristics of the medium, the topographic effect of Wenchuan earthquake is simulated by using the Spectral Element Method (SEM) algorithm and the ASTER DEM model. Results show that the high PGA (peak ground acceleration) region was distributed along the peak and the slope side away from the epicenter in the epicenter area. The overall distribution direction of high PGA and high PGV (peak ground velocity) region is parallel to the direction of the seismogenic fault. In the epicenter of the earthquake, the ground motion is to some extent amplified under the influence of the terrain. The amplification effect of the terrain on PGA is complicated. It does not exactly lead to amplification of PGA at the ridge and the summit or attenuation of PGA in the valley.

• 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.