• Environmental Analysis Health and Toxicology
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• 제11권1_2호
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• pp.1-10
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• 1996

A decrease in stratospheric ozone probably caused by chloroflurocarbons (CFCs) emissions, has been observed large parts of-the globe. It is generally accepted that if ozone levels in the stratosphere are depleted, greater amounts of shortwave ultraviolet radiationB (UVB) will reach the earth's surface, resulting in increased incidence of nonmelanoma skin cancer. In this study, we evaluated several mathematical models, such as a power and an exponential model, and a geometric model considering the surface area of a human body part and ages for the prediction of Skin cancer incidence caused by exposure to the UVB radiation. These models basically estimated the risk of skin cancer based on those measurements of the local ozone in stratosphere and UVB. Both were measured at a part of Seoul with a Dobson ozone spectrometer and Robertson-Berger UV Biometer for 1995. As a result, we calculated the point estimation applying a biological amplification factor (BAF), UVB radiation and other factors. We used a Monte-Carlo simulation technique with assumption on the distribution of each considered factor. The sensitivity analysis of model by there components conducted using Gaussian sensitivity method. The annual integral of UVB radiation was 2275 MED (minimal erythema dose)/yr. Also, an estimate of the annual amount of UVB reaching the earth's surface at a korea's latitude and altitude was 3328 MED/yr. The values of the radiation amplification factor (RAF) were ranged from 0.9 to 1.5 in Seoul. To give the effective factors required to model the prediction of skin cancer incidence caused by exposure to the UVB radiation in Korea, we studied the pros and cons of above mentioned models with the application of those parameters measured in Seoul, Korea.

• Earthquakes and Structures
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• 제5권1호
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• pp.49-65
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• 2013

This article presents the statistical characteristics of elastic floor acceleration spectra that represent the peak response demand of non-structural components attached to a nonlinear supporting frame. For this purpose, a set of stiff and flexible general moment resisting frames with periods of 0.3-3.6 sec. are analyzed using forty-nine near-field strong ground motion records. Peak accelerations are derived for each single degree of freedom non-structural component, supported by the above mentioned frames, through a direct-integration time-history analysis. These accelerations are obtained by Floor Acceleration Response Spectrum (FARS) method. They are statistically analyzed in the next step to achieve a better understanding of their height-wise distributions. The factors that affect FARS values are found in the relevant state of the art. Here, they are summarized to evaluate the amplification and/or reduction of FARS values especially when the supporting structures undergo inelastic behavior. The properties of FARS values are studied in three regions: long-period, fundamental-period and short-period. Maximum elastic acceleration response of non-structural component, mounted on inelastic frames, depends on the following factors: inelasticity intensity and modal periods of supporting structure; natural period, damping ratio and location of non-structural component. The FARS values, corresponded to the modal periods of supporting structure, are strongly reduced beyond elastic domain. However, they could be amplified in the transferring period domain between the mentioned modal periods. In the next step, the amplification and/or reduction of FARS values, caused by inelastic behavior of supporting structure, are calculated. A parameter called the response acceleration reduction factor ($R_{acc}$), has been previously used for far-field earthquakes. The feasibility of extending this parameter for near-field motions is focused here, suggested repeatedly in the relevant sources. The nonlinearity of supporting structure is included in ($R_{acc}$) for better estimation of maximum non-structural component absolute acceleration demand, which is ordinarily neglected in the seismic design provisions.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.561-567
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• 2016

After the Gyeong-ju 9.12 earthquake, we found the necessity of seismic design of nonstructural element is important to reduce damages in view of properties and economic losses. This study focused on the investigation of damages including both properties and human beings. It was found that most of the damages are leaking of water pipe line, rupture of glasses, spalling of roof finishing, cracks of building, and falling from roof. It was also found that the seismic design force of nonstructural elements is taking account into the natural periods, amplification factors, response modification factors to forsee inelastic behaviors. From this studies, it is recommended that more studies are necessary on the seismic design force of nonstructural element.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.83-90
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• 2002

Prying action caused by the eccentric loads within the equipment itself and the anchors can result in a lack of adequate stiffness and strength within the equipment and in additional moment loadings on the anchors. A typical case of prying action often found in power plants is the angle type anchorage system with expansion bolt. Experimental and analytical studies were performed to investigate the relationship between the amplification factors and various geometrical and material factors. It is revealed that the value of the factor is effected by the stiffness of bolt and angle, lateral stiffness of cabinet, and geometrical parameter of anchor system.

• 미생물학회지
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• 제44권4호
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• pp.293-298
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• 2008

HCV는 HIV등과 함께 수혈이나 혈장된 획물질을 통하여 감염되는 주요 바이러스이다. 주로 혈액이나 혈장에서 HCV에 대한 항체를 검출함으로서 HCV의 감염을 방지하고 있다. 그러나 바이러스에 감염되었으나 항체가 생성되기 이전이나 항체의 양이 적은 경우에는 HCV의 검출이 어렵다. 따라서 핵산중폭시험(nucleic acid amplification tests, NAT)을 이용한 HCV 유전자를 검출하려는 시도들이 진행되고 있다. 이 연구의 목적은 혈장분획물질에서 HCV RNA를 검출할 수 있는 핵산증폭시험 방법을 개발하는 것이다. 5종류의 PCR primer를선별하여 실험에 이용하였다. 혈장분획물질의 HCV RNA 추출에는 컬럼 방법을 이용하는 것이 유용한 것으로나타났다. 핵산중폭시험의 결합 온도는 $48^{\circ}C$가 가장 적절한 것으로 나타났다. 또한 2차 PCR의 경우, 1차 PCR 산물 $1{\mu}l$와 30 pmol의 primer즐 사용하였을 때 높은 민감도와 특이성을 보이는 것을 알 수 있었다. 혈장 분획물질에 HCV를 주입하여 혈장중폭시험을 수행한 결과, 100 IU/ml까지 검출 할 수 있었다. 한편 근육주사용항체(IMIG)의 경우 핵산중폭시험을 통한 검출한계는 100IU/ml로 COBAS amplicor HCV2.0의 500 IU/ml 이상의 검출한계보다 민감도가 더 높은 것으로 나타났다. 이러한 결과들로 보아 본 실험에 이용된 핵산증폭시험이 혈장분획물질에서 HCV RNA를 검출하는데 유용한 방법으로 사용될 수 있을 것으로 생각된다.

• 웰빙융합연구
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• 제2권2호
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• pp.19-37
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• 2019

Over the last few decades, the atmospheric carbon dioxide emission has been amplified to a great extent in Turkey. This amplification may cause global warming, climate change and environmental degradation in Turkey. Consequently, ecological condition and human life may suffer in the near future from these indicated threats. Therefore, an attempt was made to test the relationship among a number of expected factors and carbon dioxide emissions in the case of Turkey. The study covers the time series data over the period of 1970-2017. We employed the modern econometric techniques such as Johansen co-integration, ARDL bound testing approach and the block exogeneity. The results of the Johansen co-integration test show that there is a significant long-run relationship between carbon dioxide emissions and expected factors. The long-run elasticities of the ARDL model show that a 1% increase in the GDP per capita, electric consumption, fiscal development and trade openness will increase carbon dioxide emissions by 0.14, 0.52, 0.09 and 0.20% respectively. Further, our findings reveal that the environmental Kuznets curve (EKC) hypothesis and inverted U-shaped relationship between carbon dioxide emission and economic growth prevails. Therefore, the EKC hypothesis is valid and prevailing in the Turkish economy. The diagnostic test results show that the parameters of the ARDL model are credible, sTable and reliable in the current form. Finally, Block exogeneity analysis displays that all the expected factors are contributing significantly to carbon dioxide emissions in the Turkish economy.

• 한국항공우주학회지
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• 제41권1호
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• pp.17-24
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• 2013

본 논문에서는 복합재료의 미시적 파손모드를 고려하는 복합재 파손예측 프로그램을 개발하였다. 개발된 프로그램의 검증을 위하여 원공이 있는 복합재 적층판 시편의 인장시험 및 정적 파손해석을 수행하였다. 먼저 적층각도별 복합재 시편에 대한 인장시험을 통하여 논문에 사용된 재료에 대한 SIFT 허용치를 산출하였고, 미시역학적 모델인 RVE에 대한 유한요소 해석을 통하여 변형률 증폭계수를 결정하였다. 또한 원공이 있는 복합재 적층판 시편에 대한 인장시험을 수행하고, 실험을 통해 얻어진 파손하중 결과를 바탕으로 유한요소 모델에 대하여 정적 파손해석을 수행하였다. 마지막으로 실험결과를 바탕으로 예측된 파손지수 결과를 평가함으로써 개발된 프로그램의 효용성을 검증하였다.

• 한국지진공학회논문집
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• 제20권4호
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• pp.245-256
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• 2016

In the companion paper (I - Database and Site Response Analyses), site-specific response analyses were performed at more than 300 domestic sites. In this study, a new site classification system and design response spectra are proposed using results of the site-specific response analyses. Depth to bedrock (H) and average shear wave velocity of soil above the bedrock ($V_{S,Soil}$) were adopted as parameters to classify the sites into sub-categories because these two factors mostly affect site amplification, especially for shallow bedrock region. The 20 m of depth to bedrock was selected as the initial parameter for site classification based on the trend of site coefficients obtained from the site-specific response analyses. The sites having less than 20 m of depth to bedrock (H1 sites) are sub-divided into two site classes using 260 m/s of $V_{S,Soil}$ while the sites having greater than 20 m of depth to bedrock (H2 sites) are sub-divided into two site classes at $V_{S,Soil}$ equal to 180 m/s. The integration interval of 0.4 ~ 1.5 sec period range was adopted to calculate the long-period site coefficients ($F_v$) for reflecting the amplification characteristics of Korean geological condition. In addition, the frequency distribution of depth to bedrock reported for Korean sites was also considered in calculating the site coefficients for H2 sites to incorporate sites having greater than 30 m of depth to bedrock. The relationships between the site coefficients and rock shaking intensity were proposed and then subsequently compared with the site coefficients of similar site classes suggested in other codes.

• 한국지반공학회지:지반
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• 제9권1호
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• pp.7-20
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• 1993

1988년 건설부에서 제정한 건축물에 대한 재진설계규준'에는 저면 전단력 산정시 지반계수가 1.0, 1.2, 1.5로 구분되어 있는데, 특히 얕은지반의 연약층에서 지반계수의 선정이 모호할 때가 많다. 또한 우리나라의 지반특성은 대부분 퐁화암 및 연암층이 20m이내에서 발견됨을 고려하여, 일차원 파전파 이론과 반무한 탄성이론 및 문헌을 통한 분석을 통해 지진 하중시 지반의 조건이 저면 전단력에 미치는 증폭효과를 비교분석하여 내진 설계시 적절한 지반계수 선택을 할 수 있도록 하였다.

• 대한토목학회논문집
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• 제9권2호
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• pp.1-10
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• 1989

본 연구에서는 열차가 일정한 속도로 주행할 때 트러스교에 얼어나는 동적응답을 구해보았다. 해석은 Householder 변환과 QL법을 이용하여 고유치해석을 실시한 후 이를 토대로 모든중첩법에 의해 동적응답을 구했으며, 이것의 타당성을 밝히기 위해서는 먼저 아주 느린 속도로 하중이 주행할 때 얻어지는 응답을 정적해석프로그램에 의한 결과치와 비교하였고, 동적응답은 직접 적분법에 의한 결과 치와 비교해 보았다. 그리고 이를 토대로 열차의 속도와 형태의 변화에 따른 동적확대계수의 변화를 살펴보았으며, 또한 그것들을 시방서 규정과 비교해 보았다. 그 결과 열차의 속도가 낮은 경우 동적확대계수는 열차의 형태에 관계없이 비교적 낯은 값이 있었으나 속도가 높아질수록 형태에 따라 크게 다르고, 전도차 및 U. I. C. 하중의 경우는 그값이 시방서 규정을 초과하는 경우도 있음을 알수 있었다.