• 한국식품영양학회지
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• 제28권2호
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• pp.202-218
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• 2015

Many countries have introduced new imported food safety measures, following the accident at Fukushima Daiichi Nuclear Power Station. This study was conducted to evaluate the measures contents and effects on food trades values. Eight percent of members were notified the introduced measures to the World Trade Organization. The measures' contents were banning imports, enhancing inspection and adding certification requirement. The covered regions were some prefectures, entire Japan or all affected countries. European Union introduced a measure that subjecting foods originating from 12 prefectures to import at designated ports with required certification. The measures were amended 8 times until March 2014 to apply listed foods from 15 prefectures. The trade value of fishery products and miscellaneous foods were affected. Australia introduced a measure that required additional inspection of dairy, fishery and plants products from 13 prefectures with subsequent amendments. The trade value had no effect in tested foods. Chinese Taipei introduced a temporary import ban for all foods from 6 prefectures. Trade values for fruits were affected. The United States issued an import alert for detention without examination for listed prefectures and goods without introducing new measures. Although no specific products were affected, trade values for all foods were affected.

• Computers and Concrete
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• 제16권5호
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• pp.723-740
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• 2015

In this study, the seismic performance of skewed highway bridges has been assessed by using fragility function methodology. Incremental Dynamic Analysis (IDA) has been used to prepare complete information about the different damage states of a 30 degree skewed highway bridge. A three dimensional model of a skewed highway bridge is presented and incremental dynamic analysis has been applied. The details of the full nonlinear procedures have also been presented. Different spectral intensity measures are studied and the effects of the period on the fragility curves are shown in different figures. The efficiency, practicality and proficiency of these different spectral intensity measures are compared. A suite of 20 earthquake ground motions are considered for nonlinear time history analysis. It has been shown that, considering different intensity measures (IM) leads us to overestimate or low estimate the damage probability which has been discussed completely.

• International Journal of Concrete Structures and Materials
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• 제6권4호
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• pp.209-220
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• 2012

Post-earthquake fire (PEF) can lead to a rapid collapse of buildings that have been partially damaged as a result of a prior earthquake. Almost all standards and codes for the design of structures against earthquake ignore the risk of PEF, and thus buildings designed using those codes could be too weak when subjected to a fire after an earthquake. An investigation based on sequential analysis inspired by FEMA356 is performed here on the immediate occupancy (IO), life safety (LS) and collapse prevention (CP) performance levels of two portal frames, after they are pushed to arrive at a certain level of displacement corresponding to the mentioned performance level. This investigation is followed by a fire analysis of the damaged frames, examining the time taken for the damaged frames to collapse. As a point of reference, a fire analysis is also performed for undamaged frames and before the occurrence of earthquake. The results indicate that while there is minor difference between the fire resistances of the fire-alone situation and the frames pushed to the IO level of performance, a notable difference is observed between the fire-alone analysis and the frames pushed to arrive at LS and CP levels of performance and exposed to PEF. The results also show that exposing only the beams to fire results in a higher decline of the fire resistance, compared to exposing only the columns to fire. Furthermore, the results show that the frames pushed to arrive at LS and CP levels of performance collapse in a global collapse mode laterally, whereas at the IO level of performance and fire-alone situation, the collapse mechanism is mostly local through the collapse of beams. Whilst the investigation is conducted for a certain class of portal frames, the results confirm the need for the incorporation of PEF into the process of analysis and design, and provide some quantitative measures on the level of associated effects.

• 문화기술의 융합
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• 제4권1호
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• pp.307-314
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• 2018

2016, 2017년 연속으로 발생한 경주지진과 포항지진으로 인해 한국사회가 더 이상 지진에 대해 안전하지 않다는 점이 명백해졌다. 불행히도 한국의 건축 산업은 이제까지 지진에 대한 대비가 매우 미흡하여 많은 건물이 지진으로 인해 피해를 입었으며 다음과 같은 문제점이 존재한다. 첫째, 내진성능 확보 비율이 낮다. 둘째, 지진과 화재에 매우 취약한 필로티 구조 건물의 비중이 최근에 매우 높아졌다. 셋째, 안전성 확보를 위한 건축법 적용에서 제외되는 소규모 건축물의 비중이 너무 높다. 넷째, 관행화된 부패와 부실시공이 안전성을 저해한다. 따라서 이러한 상황에서 지진재난 대비를 위한 조치는 다음과 같다. 첫째, 지진에 취약한 건축물의 부족한 내진성능을 확보하기 위해 건물의 구조체를 보강하는 방법과 건물에 작용하는 지진하중을 경감시키는 방법을 활용한다. 둘째, 부패로 인한 부실시공을 방지하기 위해 내부고발자를 활용하고 적극적으로 보호한다. 이를 위해 내부고발자를 조직에 대한 배신자가 아니라 안전이라는 공익을 보호하기 위한 적극적 수단으로 인식해야 한다.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.192-205
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• 2020

Seismic design practices and seismic response analyses of civil structures and nuclear power plants (NPPs) have conventionally used the peak ground acceleration (PGA) or spectral acceleration (S_a) as an intensity measure (IM) of an earthquake. However, there are many other earthquake IMs that were proposed by various researchers. The aim of this study is to investigate the correlation between seismic responses of NPP components and 23 earthquake IMs and identify the best IMs for correlating with damage of NPP structures. Particularly, low- and high-frequency ground motion records are separately accounted in correlation analyses. An advanced power reactor NPP in Korea, APR1400, is selected for numerical analyses where containment and auxiliary buildings are modeled using SAP2000. Floor displacements and accelerations are monitored for the non- and base-isolated NPP structures while shear deformations of the base isolator are additionally monitored for the base-isolated NPP. A series of Pearson's correlation coefficients are calculated to recognize the correlation between each of the 23 earthquake IMs and responses of NPP structures. The numerical results demonstrate that there is a significant difference in the correlation between earthquake IMs and seismic responses of non-isolated NPP structures considering low- and high-frequency ground motion groups. Meanwhile, a trivial discrepancy of the correlation is observed in the case of the base-isolated NPP subjected to the two groups of ground motions. Moreover, a selection of PGA or S_a for seismic response analyses of NPP structures in the high-frequency seismic regions may not be the best option. Additionally, a set of fragility curves are thereafter developed for the base-isolated NPP based on the shear deformation of lead rubber bearing (LRB) with respect to the strongly correlated IMs. The results reveal that the probability of damage to the structure is higher for low-frequency earthquakes compared with that of high-frequency ground motions.

• Earthquakes and Structures
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• 제6권5호
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• pp.473-494
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• 2014

Progressive collapse, which is referred to as the collapse of the entire building under local damages, is a common failure mode happened by earthquakes. The collapse process highly depends on the whole structural system. Since, asymmetry of the building plan leads to the local damage concentration; it may intensify the progressive collapse mechanism of asymmetric buildings. In this research the progressive collapse of regular and irregular 6-story RC ordinary moment resisting frame buildings are studied in the presence of the earthquake loads. Collapse process and collapse propagation are investigated using nonlinear time history analyses (NLTHA) in buildings with 5%, 15% and 25% mass asymmetry with respect to the number of collapsed hinges and story drifts criteria. Results show that increasing the value of mass eccentricity makes the asymmetric buildings become unstable earlier and in the early stages with lower number of the collapsed hinges. So, with increasing the mass eccentricity in building, instability and collapse of the entire building occurs earlier, with lower potential of the progressive collapse. It is also demonstrated that with increasing the mass asymmetry the decreasing trend of the number of collapsed beam and column hinges is approximately similar to the decreasing trend in the average story drifts of the mass centers and stiff edges. So, as an alternative to a much difficult-to-calculate local response parameter of the number of collapsed hinges, the story drift, as a global response parameter, measures the potential of progressive collapse more easily.

• 기술사
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• 제44권3호
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• pp.20-24
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• 2011

According to Natural disasters due to extreme weather, In particular earthquake, It has become important to avoid by aseismic design. Do not entrust with it to non-specialists. By all means, It has to be Structural Professional Engineers. Therefore, foresee and Prevent problems in the near future.

• 한국콘텐츠학회논문지
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• 제20권1호
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• pp.470-484
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• 2020

2017년 11월 15일 포항지역에서 규모 5.4로 지진이 발생하여 건물 및 시설이 피해를 입었고, 최대 1,797명의 이재민이 생겼다. 발생 당시 신속하게 피해 파악, 대피소 운영 등의 초기대응은 이루어졌지만, 지진재해 복구대응에서 몇 가지 문제점이 발생했다. 복구대응으로 임시주거시설 제공, 재난지원금 지급과 같은 지원이 이루어졌는데, 복구지원 제도에 대한 안내 및 홍보가 부족하여, 지진 피해자들 중 일부는 지원을 받지 못하는 문제가 있었다. 일본에서는 잦은 지진의 경험으로 실효성 높은 복구대책을 마련하고 있었는데, 그 중 지진피해 복구지원 제도를 정리한 가이드북을 제작·배급하여 피해자들이 신속히 일상생활로 복귀하도록 하고 있다. 본 연구에서는 포항지진 피해 복구 사례를 토대로 국내 지진재해 복구대응 현황과 문제점을 분석하고, 일본 지진 피해 복구·부흥대응의 선진사례 조사를 통해 국내 지진재해 복구대책의 개선방안을 도출하고 있다. 나아가 국내의 실질적인 지진피해 복구대책 방안마련으로 한국형 지진피해자 지원 가이드북을 개발·제안하고자 하였다.

• Steel and Composite Structures
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• 제19권3호
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• pp.697-711
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• 2015

It is well known the importance of considering hysteretic energy demands for the seismic assessment and design of structures. In such a way that it is necessary to establish new parameters of the earthquake ground motion potential able to predict energy demands in structures. In this paper, several alternative vector-valued ground motion intensity measures (IMs) are used to estimate hysteretic energy demands in steel framed buildings under long duration narrow-band ground motions. The vectors are based on the spectral acceleration at first mode of the structure Sa($T_1$) as first component. As the second component, IMs related to peak, integral and spectral shape parameters are selected. The aim of the study is to provide new parameters or vector-valued ground motion intensities with the capacity of predicting energy demands in structures. It is concluded that spectral-shape-based vector-valued IMs have the best relation with hysteretic energy demands in steel frames subjected to narrow-band earthquake ground motions.

• Earthquakes and Structures
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• 제10권3호
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• pp.645-667
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• 2016

The 750 m long "De Bosset" bridge in the Cephalonia Island of Western Greece, being the area with the highest seismicity in Europe, was constructed in 1830 by successive stone arches and stiff block-type piers. The bridge suffered extensive damages during past earthquakes, such as the strong M7.2 earthquake of 1953, followed by poorly-designed reconstruction schemes with reinforced concrete. In 2005, a multidisciplinary project for the seismic assessment and restoration of the "De Bosset" bridge was undertaken under the auspices of the Greek Ministry of Culture. The proposed retrofitting scheme combining soil improvement, structural strengthening and reconstruction of the deteriorated masonry sections was recently applied on site. Design of the rehabilitation measures and assessment of the pre- and post-interventions seismic response of the bridge were based on detailed in-situ and laboratory tests, providing foundation soil and structural material properties. In-situ inspection of the rehabilitated bridge following the strong M6.1 and M6.0 Cephalonia earthquakes of January 26th and February 3rd 2014, respectively, revealed no damages or visible defects. The efficiency of the bridge retrofitting is also proved by a preliminary performance analysis of the bridge under the recorded ground motion induced by the above earthquakes.