• Computers and Concrete
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• v.34 no.3
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• pp.355-365
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• 2024

TECSolverApp is an application that calculates the total equivalent seismic load (base shear) and shows the design spectra in accordance with the Turkish Earthquake Code (TEC). TECSolverApp software can present the spectral acceleration-period graph and the base shear (in terms of unit building weight) in MATLAB and .NET Core frameworks according to TEC 2007 and TEC 2018. In the software, three different building period evaluation options were provided, as entering the period directly, empirical calculation, and using the period calculation formula. In different period calculation scenarios, particular design input parameters such as site-specific spectral acceleration coefficients, local soil class, building importance coefficient, and structural system behavior coefficient are expected. TECSolverApp was produced in two different programming languages and published in MATLAB App Designer and ASP.NET Core MVC environments. To be shared in MATLAB App Designer, it was aimed at availability through the program and distributability as a desktop application. By deploying in ASP.NET Core MVC, open-source cross-platform coding and web-based accessibility were targeted. One of the strongest aspects of TECSolverApp is its developability thanks to software architecture. In this respect, it can be foreseen that other international seismic codes can be added to the calculations in the future.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.51-57
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• 2001

In order to estimate attenuation characteristics, nonparametric model is used. Evaluation of this model requires suites of average spectral amplitude data as a function of distance without adopting any assumed parametric forms. Values of Quality factor, Q were estimated for individual frequencies by matrix inversion of S wave amplitude spectra for 21 records of 8 small and intermediate earthquakes (2.7$(1/r)^{1/2}$. The best models for 1/Q values were found to be 0.000453+0.001851/f and 0.000451+0.009261/f, respectively. This results can be compared to the conventional functional form of Q=$af^{b}$ and be used to estimate source spectra and site response.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.3
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• pp.99-105
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• 2000

한반도 동남부 지역에서 발생하고 관찰된 약진 또는 중진의 자료를 이영하여 이 지역의 Q값과 지진원의 특성인 모서리 주파수 (fc), 응력강하량(Δ$\delta$) 및 모멘크규모 (Mw)를 산정하였다. 가속도 스펙트럼의 경사와 관련된 x의 통계학적 분포로부터 추정한 Q의 95% 신뢰범위는 1656~2454 이다. 1998년 1월 18일 울산 앞바다 지진과 1997년 6월 26일 경주지진의 지진원 요소를 구한 결과 fc 는 각각 4.22Hz , 2.94Hz, Δ$\delta$는 각각 106.8 bar, 106.2 bar, Mw는 각각 3.9, 4.0으로 추정되었다. 제한된 자료수로 인하여 이들의 통계학적 성질을 충분히 규명하지는 못하였지만 다른 연구자들의 기존결과와 유사한 값을 보인다. 본 연구의 결과는 강진동 모사에 직접 이용이 가능하며, 이 지역에 위치한 원자력 발전소 내진 안전성 검토에도 이용될 수 있다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.9
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• pp.622-629
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• 2004

In practical control systems, the capacity of actuators is limited and this degrades the system performances and it is often a source of instability. To use full capacity of actuators, we adopt the gain scheduled control permitting the over saturation in controls. The basic idea of gain scheduled control is to use a higher gain control when the state variables are smaller and a lower gain control when the state variables are larger. First, we derive a constant H control and a reachable set while satisfying the degree of over saturation. Next, we divide this set into nested subsets and find $H_{\infty}$ controls at rack subsets while satisfying the degree of over saturation. Finally, the control gain is applied according to the status of states. Note that all procedures are done by solving linear matrix inequalities(LMI). Finally, we show the validity and applicability of our proposed control using the simulations of a six-story building subjected to the earthquake excitation.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.45-51
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• 1999

The attenuations of peak vertical displacements are studies using a conventional least squeare regression technique for microearthquakes occurred in the Kyungsang Basin southeastern Korea. The regression model applied to bandpass-fitered ground motion data includes parameters to account for geometric spreading anelastic attenuation depending on frequency source size and station site effects. Thirty nine displacement traces obtained by integrating velocity records for six shallow local microearthquakes are used to determine attenuation characteristics in the Basin. The regression result of the peak amplitude data leads to Q(f)=59.9 {{{{ {f }^{0.955 } }} for 1.5Hz$\leq$ f $\leq$ 25 Hz. It appears that the anelastic attenuation in the Kyungsang Basin is greater than that in the Western North America Area.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.6 no.1
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• pp.29-35
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• 2010

Long-term temperature monitoring has been performed for ground heat exchanger at the Earthquake Research Center (ERC) building in Korea Institute of Geoscience and Mineral Resources (KIGAM). For the 3 years of monitoring, overall temperature increases are observed at various depths within a borehole heat exchanger. But monitoring of ground temperature variation at the monitoring well beforehand showed that geothermal utilization is not the only source for the temperature increase, Because various kinds of sources can cause the ground temperature change, more thorough investigation should be followed.

• Structural Engineering and Mechanics
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• v.66 no.1
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• pp.75-84
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• 2018

This study presents the reliability-based analysis of nonlinear structures using the analytical fragility curves excited by random earthquake loads. The stochastic method of ground motion simulation is combined with the random vibration theory to compute structural failure probability. The formulation of structural failure probability using random vibration theory, based on only the frequency information of the excitation, provides an important basis for structural analysis in places where there is a lack of sufficient recorded ground motions. The importance of frequency content of ground motions on probability of structural failure is studied for different levels of the nonlinear behavior of structures. The set of simulated ground motion for this study is based on the results of probabilistic seismic hazard analysis. It is demonstrated that the scenario events identified by the seismic risk differ from those obtained by the disaggregation of seismic hazard. The validity of the presented procedure is evaluated by Monte-Carlo simulation.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.57-60
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• 1999

Amplification factor spectrum using the observed strong ground motions database in the Korean Peninsula has been obtained and compared with Standard Rpectrum which wa suggested by United States Nuclear Regulatory Committee. The observed ground motions from the Yongwol and the Kyoungju Earthquakes respectively which are supposed to represent domestic seismotectonic characteristics such as seismic source attenuation of the propagation meium and site specific effect are used for the analysis of amplification factor spectrum,. The database are slightly different from the those of the second study. Amplification factors have been calculated by comparing the observed peak ground motions with results from responses to the observed horizontal na vertical ground motions. The comparison have shown that the amplification factors resultant from this study exceeds those of Standard Response Spectrum The results suggest that the characteristics of seismic strong ground motion which are supposed to represent the domestic seismotectonic characteristics differs from those of Standard Response Spectrum especially at higher frequencies. The results from the 2nd study are similar to those of 1st analysis.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.143-150
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• 1999

Elastic wave propagation in a multilayered elastic half-plane is studied by using the Cagniard-de Hoop method. After the unknowns are expressed in terms of the reflection and transmission coefficients in the in terms of the reflection and transmission coefficients in the integral-transformed domains they are assmbled to form the global matrix equation. The inverse Laplace transform of each term is done by applying the Cagniard-de Hoop methods. As a numerical example a four-layered half-plane is considered where a point source is applied to the first layer. The method described in the present study can be used in checking other numerical methods such as FDM.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.6
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• pp.361-368
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• 2016

Coupling beams serve as primary source of energy dissipation in coupled shear wall systems during large earthquakes. However, the overestimation of the shear strength of diagonally reinforced coupling beams may be adverse effect on the seismic performance of coupled shear wall systems. In order to force coupling beams to properly work during earthquakes, coupling beams should be designed with accurate shear strength equations. The objective of this study is to propose the accurate shear strength equation for slender diagonally reinforced coupling beams. For this purpose, experimental tests were conducted using three diagonally reinforced coupling specimens with different amount of transverse reinforcement under reversed cyclic loads to evaluate the hysteretic behavior of the specimens. The test results show that transverse reinforcement of slender diagonally reinforced coupling beam affects the maximum strength and drift ratio.