• Journal of Genetic Medicine
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• 제17권2호
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• pp.68-72
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• 2020

Purpose: Trisomy 21, the cause of Down syndrome (DS) with various medical problems, is the most common aneuploidy during the fetal period. For diagnosis, a non-invasive screening test using maternal blood, which cannot be confirmed and invasive confirmation test with a risk of miscarriage, may be performed. The trophoblast retrieval and isolation of the cervix (TRIC) have been proposed by some researchers as an alternative to overcome the limitations of current tests. We experimented using TRIC to identify the possibility of trisomy 21 for the first time in Asia. Materials and Methods: Three cases of DS were analyzed confirmed by invasive tests (chorionic villus sampling, amniocentesis). All samples of trophoblasts immediately were immersed in phosphate-buffered saline and processed with formalin for fixation. The trophoblasts were isolated using an anti-human leukocyte antigen-G antibody coupled to magnetic nanoparticles. β-human chorionic gonadotropin (hCG)-expressing cells were considered as trophoblast cells, and the detection rate calculated. DS was confirmed by fluorescence in situ hybridization (FISH). Results: The mean trophoblast detection rate using β-hCG was 78.1%, and the detection rate using FISH was 22.2%. In all cases, the trisomy of chromosome 21 was identified. Conclusion: Trophoblast can be obtained from the five weeks of gestation and has a high detection rate, so it is noted that it can replace the current prenatal genetic test. To realize the clinical application as a prenatal genetic test, we will need additional efforts to identify trisomy 21 as well as other chromosomal abnormalities in future large-scale studies.

• 한국항공우주학회지
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• 제45권2호
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• pp.99-105
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• 2017

공력탄성학적 현상들을 확인하는 방법 중 하나인 풍동실험은 축소 모델을 제작해야하기 때문에 복잡하고 비용이 많이 들며, 유동 속도의 제한이 있는 등의 단점이 있다. 이러한 단점을 보완하여 풍동실험을 대체할 수 있는 Dry Wind-Tunnel(DWT) 기법이 제안되었다. 이는 지상 진동 실험 장치와 공기력을 계산하는 소프트웨어로 구성되어 실시간으로 유체의 영향을 고려해준다. 본 연구에서는 DWT의 핵심적인 요소인 실시간 공기력 계산프로그램을 개발하고, 구조 모델을 소프트웨어로 표현하여 두 시스템을 실시간 연동해 플러터 해석을 수행하였다. Matlab Simulink와 dSPACE를 이용하여 실시간 플러터 해석을 수행하고 이를 상용프로그램인 ZAERO를 사용한 결과와 비교하여 검증하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 3차
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• pp.55-60
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• 2010

Rockfill zones in CFRD consist typically of large granular materials, usually the maximum particle size up to several meters, which makes laboratory testing to determine the mechanical properties of rockfill difficult. Commonly, the design strength of the rockfills is obtained by scaling down the original rockfill materials and performing laboratory strength tests for the reduced size materials. The objective of the present study is to investigate the effect of particle size on the shear behavior and the strength for granular materials. A series of large-scale triaxial tests was conducted on large granular materials with the maximum particle size varying from 20 to 50mm. The test results showed that overall shear behaviors were similar between the samples with different particle sizes while there were slight differences in the magnitudes of the peak shear stress between the samples. In addition, a simulation of the granular material with the max. particle size of 20mm was performed using DEM code, $PFC^{2D}$, and compared with the test results. The deviatoric stress versus strain behaviors of experimental and numerical tests were found to be matched well up to the peak stress state.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.569-572
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• 2010

초음속 추력편향 노즐의 시험 평가를 위한 시험 장치를 설계 하였다. 본 시험 장치는 축소된 모델추력편향장치를 이용하여 초음속 추력 편향시의 축추력, 모멘트, 배기가스 속도 및 압력 등을 측정하여 다양한 기하학적 변수에 대한 노즐의 성능특성을 이해하고자 한다. 본 시험장치는 고압 공기저장장치, 유량조절 및 측정장치, 시험노즐과 계측시스템으로 구성되어 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.682-683
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• 2013

• 한국연소학회지
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• 제9권1호
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• pp.1-10
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• 2004

The results of a series of experiments executed by using two pilot-scale oxy-fuel burners are presented. The oxy-fuel burners are designed for maximum capacity of 50,000kcal/hr, 200,000kcal/hr and installed in the test furnace. The effects of turn-down ratio, excess oxygen ratio, nozzle exit velocity, injection angle, and swirl vane angle on the combustion characteristic are investigated. Temperature distributions are measured using R-type and Molybdenum sheathed C-type thermocouple at various points of the flame. The results showed that maximum temperature and mean temperature increase with the increase of turn-down ratio and momentum. The maximum flame temperature was increased about 35% compared to the case of equivalent air operated condition. In addition, optimum burner type, excess oxygen ratio and nozzle characteristics are obtained for this oxy-fuel glass melting furnace.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.605-612
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• 2008

The shear wave velocity ($V_s$) has been commonly used to evaluate the dynamic properties of soil. The field $V_s$ probe (FVP) was already developed to assess the shear stiffness of a soft clay. The objective of this study is to investigate the disturbance effects of the FVP due to the penetration. The laboratory tests are conducted in a large-scale consolidometer (calibration chamber). The reconstituted clay is mixed at the water content of 110% using a slurry mixer. The FVP and down-hole test are carried out every 1cm interval to compare the data. In addition, two square rods with transducers are also implemented to get the reference value. The shear waves evaluated by the FVP, dow-hole tests, and reference rods are closely matched. This study suggests that the disturbance effect of the FVP due to the penetration into the soft clay soils is small enough and the $V_s$ evaluated by the FVP reflects well the in-situ characteristics. Furthermore, the combination of the FVP and down-hole test shows the possibility of hybrid equipment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.219-221
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• 1999

HVDC(High Voltage Direct Current) transmission system was constructed between Cheju island and mainland Haenam and has been operating commercially since 1998. But research activities in this area are not so much. That is caused by the facts that HVDC is large scale system and it is not so easy to implement and to test. Though such simulation tools as RTDS(Real Time Digital Simulator) and EMTDC can be useful, these have limitations for actual control and protective system design. Therefore scaled-down HVDC model was developed for the purpose of researches at operating technique, control and protection methods. The design of this model was based on real Cheju-Haenam HVDC system. And additionally faults simulator such as ground fault, short-circuit and change of impedance in transmission line is equipped for analysis of these faults. Control system of the model was implemented fully digitally. So it is very easy for the researchers to develope control and protection algorithm and to test the performance.

• 한국터널지하공간학회 논문집
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• 제6권1호
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• pp.61-70
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• 2004

최근 현장 타설 콘크리트 터널 라이닝의 시공 및 유지관리상 문제점을 개선하기 위해 노르웨이에서 개발된 프리캐스트콘크리트라이닝에 대한연구가 활발히 진행되고 있다. 그러나 북유럽지역에서는 지진이 거의 발생되지 않기 때문에 PCL공법 적용시 지진하중으로 인한 영향을 고려하지 않았다. 따라서 PCL공법을 국내에 도입하기 위해서는 지진하중으로 인한 PCL의 영향분석을 선행하여야 할 것으로 판단되어 본 연구에서는 지진하중으로 인한 PCL의 안정성 검토를 수행하고자 하며 이를 위해 실물을 1/5로 축소한 모델체에 대한 진동대 실험을 수행하였으며 PCL의 내진성능평가를 수행하였다. 연구결과, 대섬도터널에서 PCL공법을 적용할 경우, 국내의 내진설계 기준에 만족하는 결과를 얻을 수 있었다.

• 한국항공운항학회지
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• 제12권2호
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• pp.1-15
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• 2004

In this study, we analyze technical requirements for a 50m unmanned airship order to assure safety in the test flight operation. The 50m class unmanned airship developed by Airship Group in Korea Aerospace Research Institute(KARI). The 50m class unmanned airship was developed as a scale-down model of 200m class stratosphere unmanned airship. This study reviews specifications and characteristics of 50m class unmanned airship and develops Airworthiness Requirements on the basis of current effective Aviation Act, Airworthiness standards, and relevant international documents. The developed requirements can be applied to the safety assessment of the 200m class stratosphere unmanned airship.