• 환경생물
• /
• 제23권2호
• /
• pp.152-156
• /
• 2005

Ionizing radiation is a well- known therapy factor for human carcinoma cells. Genotoxic stress mediates cell cycle control, transcription and cellular signaling. In this work, we have used a microarray hybridization approach to characterize the cell type-specific transcriptional response of human carcinoma MCF-7 and HeLa cell line to $\gamma-radiation$, such as 4Gy 4hr. We found that exposure to $\gamma-ray$ alters by at least a $log_2$ factor of 1.0 the expression of known genes. Of the 27 genes affected by irradiation, 11 are down- regulated in MCF-7 cells and 2 genes induced by radiation,15 are repressed in HeLa cells. Many genes were involved in known damage- response pathways for cell cycling, transcription factor and cellular signaling response. However, in MCF-7 cells, we observed gene expression pattern in chromatin, apoptosis, stress, differentiation, cytokine, metabolism, ribosome and calcium. In HeLa cells, it showed clearly the expression changes in adhesion and migration, lysosome, brain, genome instability and translation. These insights reveal new therapy directions for studying the human carcinoma cell response to radiation.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.824-828
• /
• 2007

In this paper Statistical Energy Analysis has been considered to predict middle, high frequency air borne interior noise. PIM method is used for verification. Damping loss factor and coupling loss factor have been derived from the response(SPL) of sub systems when the power is applied. The airborne SEA model of vehicle is modeled through AutoSea2. Insulation material's absorption coefficient and transmission loss are acquired from closed form solution and experiment.

• 한국강구조학회 논문집
• /
• 제9권2호통권31호
• /
• pp.229-235
• /
• 1997

임의항복강도가 강구조물의 에너지소산능력에 미치는 영향을 파악하기 위해 본 논문에서는 7개의 강뼈대구조물을 모델링하여 응답스펙트럼해석법에 적용되는 거동계수를 산출하고 그 분포상태를 결정하였다. 또한 지진하중의 임의성이 거동계수에 미치는 영향과 비교하기 위해 주어진 스펙트럼을 만족하는 4개의 인공지진을 시뮬레이션하여 적용하였다. 본 연구의 특성상 방대한 양의 시간-이력계산을 수행하여야 하므로 근사해법인 시간-이력해석법을 개발하여 신뢰도를 검토하고 적용하였다.

• Nuclear Engineering and Technology
• /
• 제34권6호
• /
• pp.586-595
• /
• 2002

The Seismic probabilistic risk assessment (SPRA) or seismic margin assessment (SMA) have been used for the seismic safety evaluation of nuclear power plant structures and equipments. For the SPRA or SMA, the reference response spectrum should be defined. The site-specific median spectrum has been generally used for the seismic fragility analysis of structures and equipments in a Korean nuclear power plant Since the site-specific spectrum has been developed based on the peak ground motion parameter, the site-specific response spectrum does not represent the same probability of exceedance over the entire frequency range of interest. The uniform hazard spectrum is more appropriate to be used in seismic probabilistic risk assessment than the site- specific spectrum. A method for modifying the seismic fragility parameters that are calculated based on the site-specific median spectrum is described. This simple method was developed to incorporate the effects of the uniform hazard spectrum. The seismic fragility parameters of typical NPP components are modified using the uniform hazard spectrum. The modification factor is used to modify the original fragility parameters. An example uniform hazard spectrum is developed using the available seismic hazard data for the Korean nuclear power plant (NPP) site. This uniform hazard spectrum is used for the modification of fragility parameters.

• Journal of Radiation Protection and Research
• /
• 제28권4호
• /
• pp.327-335
• /
• 2003

The commercially available neutron survey meter, the REM500, which uses a tissue equivalent proportional counter (TEPC) and the self-constructed TEPC were used to determine the microdosimetric quantities of several neutron calibration fields at Korea Atomic Energy Research Institute (KAERI). Microdosimetric spectra, absorbed dose, dose equivalent as well as quality factor were derived and compared with several neutron fields which were produced by using the shadow objects to make neutron scattered and being used as a kind of realistic neutron calibration fields at KAERI. The response of REM500 as a function of mean energy was evaluated with these neutron fields using the counts measured and the predetermined reference value. The response of the self-made TEPC and the REM500 was compared using one of the neutron calibration filelds of a $^{252}Cf$ source. The reference quantities of scattered neutron calibration fields were determined using a Bonner Sphere (BS). The value of frequency-mean lineal energy, dose-mean lineal energy and quality factor of two $^{252}Cf$ sources (unmoderated and $D_2O$ moderated) were determined to check the differences in the reference neutron fields between KAERI and Pacific Northwest National Laboratory (PNNL, USA) and the results were in good agreement within 1%. It means that there is no big difference in dosimetric quantifies of neutron calibration fields of two laboratories.

• Environmental Engineering Research
• /
• 제23권3호
• /
• pp.309-315
• /
• 2018

Chlortetracycline (CTC) is one of the most important compounds in antibiotic production, and its distribution has been widely investigated due to health and ecological concerns. This study presents systematic approach to optimize the high-performance liquid chromatography-tandem mass spectrometry for analyzing CTC in a multiple reaction monitoring mode ($479{\rightarrow}462m/z$). One-factor-at-a-time (OFAT) test with response surface analysis (RSA) was used as optimization strategy. In OFAT tests, the fragmentor voltage, collision energy, and ratio of acetonitrile in the mobile phase were selected as major factors for RSA. The experimental conditions were determined using a composite in cube design (CCD) to maximize the peak area. As a result, the partial cubic model precisely predicted the peak area response with high statistical significance. In the model, the (solvent composition) and (collision $energy^2$) terms were statistically significant at the 0.1 ${\alpha}$-level, while the two-way interactions of the independent variables were negligible. By analyzing the model equation, the optimum conditions were derived as 114.9 V, 15.7 eV, and 70.9% for the fragmentor voltage, collision energy, and solvent composition, respectively. The RSA, coupled with the CCD, offered a comprehensive understanding of the peak area that responds to changes in experimental conditions.

• Journal of the Korean Wood Science and Technology
• /
• 제41권6호
• /
• pp.497-506
• /
• 2013

유칼립투스(Eucalyptus globulus)의 반탄화 최적조건을 탐색하기 위하여 반응표면분석법을 이용하였다. 반탄화 바이오매스의 탄소함량은 반탄화 정도를 나타내는 severity factor (SF)에 따라 증가하였으며 바이오매스에 포함된 수소와 산소의 함량은 감소하였다. 반탄화 바이오매스의 발열량은 조건에 따라 20.23~21.29 MJ/kg을 나타냈으며 처리 전 바이오매스와 비교하여 1.6~6.9% 에너지함량이 증가한 것으로 나타났다. 바이오매스의 중량감소율은 SF 증가에 따라 증가하였다. 에너지수율에서 반탄화 온도는 중요한 인자로 작용하였으며 상대적으로 반응시간에 대한 영향은 낮았다. 최대 에너지수율은 낮은 SF에서 반탄화를 수행하였을 때 얻을 수 있었다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제17권1호
• /
• pp.1-9
• /
• 2013

철골구조에서 지진력 저항시스템으로 많이 사용되고 있는 가새골조시스템은 중심가새골조(Concentrically Braced Frames, CBF)와 편심가새골조(Eccentrically Braced Frames, EBF)로 구분하여 KBC2009 건축구조기준에서는 서로 다른 반응수정계수를 적용하여 설계하도록 되어있다. 현행 내진설계기준에서 편심가새골조에 대하여 링크 타단 접합부의 종류에 따라 모멘트 저항접합일 경우 반응수정계수는 R=8, 비모멘트 저항접합일 경우 반응수정계수 R=7로 적용하여 설계하도록 규정하고 있을 뿐 편심길이의 영향을 고려하지 않고 있다. 본 연구에서는 편심가새골조 중에서 역V형가새골조를 대상으로 비탄성 거동을 파악한 다음 편심길이에 따른 반응수정계수를 산정하여 내진설계 기준에서 제시한 값과 비교한 결과 편심가새골조에 대하여 동일한 반응수정계수를 적용하는 것은 적절하지 않음을 확인하였다.

• 설비공학논문집
• /
• 제12권4호
• /
• pp.404-413
• /
• 2000

Environmental chamber (EC) is an experimental facility used to analyze the characteristics of thermal response of testing objects by the artificial control of weather conditions. The EC in KIER can simulate the weather conditions by the control of temperature, humidity, and solar radiation. A two-storied testing building is located inside of EC. For the exact thermal response analysis of testing building, monthly or yearly scheduled operations are necessary. Although this long term operation gives the exact experimental data, it requires a high operational cost, long duration, and lots of manpower. Therefore it is necessary to perform the shortened experiments without sacrificing the validity of the obtained results. Since the characteristics of thermal response from the shortened experiments are different from the full time results, the analytical method to analyze the thermal response from the shortened experiments to estimate a full times results is developed in this study. The thermal response of testing building is performed using commercial software TRNSYS.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제9권3호
• /
• pp.18-26
• /
• 2001

Environmental chamber (EC) is an experimental facility used to analyze the characteristics of thermal response of testing objects by the artificial control of weather conditions. The EC in KIFR can simulate the weather conditions by the control of temperature, humidity, and solar radiation. A two-storied testing building is located inside EC. For the exact thermal response analysis of testing building, monthly or yearly scheduled operations are necessary. Although this long term operation gives the exact experimental data, it requires a high operational cost, long duration, and lots of manpower. Therefore it is necessary to perform the shortened experiments without sacrificing the validity of the obtained results. Since the characteristics of thermal response from the shortened experiments are different from the full time results, the analytical method to analyze the thermal response from the shortened experiments to estimate a full times results is developed in this study The thermal response of testing building is performed using commercial software TRNSYS.