운동에너지 탄에 따른 전투시스템 내의 순간화재발생에 대한 해석적 연구

이승철(Lee Seung-Chul),전우철(Jeon Woo-Chul),이해평(Lee Hae-Pyeong),이헌주(Lee Heon-Joo),이창현(Lee Chang-Hyun) 제어로봇시스템학회 2012 제어로봇시스템학회 합동학술대회 논문집 Vol.2012 No.7

본 연구는 외부 위협탄에 의한 전투시스템의 취약성을 분석하기 위한 선행연구로써, 운동에너지 탄의 종류에 따른 가상의 전투차량 내부에 적재포탄에서 순간화재발생 여부에 대한 전산해석을 수행하였다. 본 해석은 Autodyn 프로그램을 사용하였으며 순간화재발생을 판단하기 위해 Lee-Tarver ignition and growth model을 이용하였다. 본 계산에서 운동에너지 탄은 type A와 type B 두 가지로 설정하였고, 고폭탄은 COMPB, TNT 및 PBX9404를 설정하였다. 전산해석 결과, 고폭탄의 재질이 TNT와 PBX9404가 COMPB 재질보다 순간화재발생 확률이 상당히 높음을 알 수 있고 type B의 운동에너지 탄이 type A 보다 순간화재발생 확률이 다소 높음을 알 수 있었다.

운동에너지 탄과 적재포탄에 따른 전투시스템 내부에서의 순간화재발생에 대한 전산해석

이승철,전우철,이해평,이헌주,Lee, Seung-Chul,Jeon, Woo-Chul,Lee, Hae-Pyeong,Lee, Heon-Joo 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.6

In this paper, numerical analysis was performed about whether the flash fire of loaded shells breaks out in the virtual combat vehicle according to sorts of the kinetic energy ammunition as the preceding research for vulnerability analysis inside the combat system by an external threaty ammunition. In this simulation, Autodyn program was used and the Lee-Tarver ignition and growth model was used to determine the flash fire outbreak. In this study, the kinetic energy ammunition was set of type A and type B in two kinds and the loaded shells was set of COMPB, TNT, PBX9404 and ANB. As a result, TNT and PBX9404 have much higher flash fire probability than COMPB in high explosive, ANB has very low flash fire probability.

철도터널 내 화재 시 대피환경 확보를 위한 임계속도 산정식의 유효성 평가

이승철,이재헌,이승호,Lee, Seung-Chul,Lee, Jae-Heon,Lee, Seung-Ho 한국터널지하공간학회 2004 터널기술 Vol.6 No.1

본 연구에서는 3차원 전산유체역학 기법을 이용하여 열차터널 내 10MW급 화재발생 시, 대피환경에 대한 1차원 임계속도의 유효성을 평가하였다. 또한 터널의 입구속도가 1m/s, 2m/s (임계속도) 그리고 3m/s일 때의 터널 내 기류분포, 온도분포, 가시거리분포 및 오염물질분포가 대피환경에 미치는 영향을 각각 검토하였다. 그 결과, 세 가지 경우모두, 승객의 안전한 대피환경을 충분하게 제공하지 못할 것으로 예상되어 승객들은 유동방향 하류로 대피하여야 한다. 그러나 3m/s 입구속도의 경우는 1m/s, 2m/s의 경우 보다 승객의 대피환경에 있어서 좀 더 나은 결과를 보인다. 따라서 터널의 방재시스템의 설계 시, 안전한 대피환경을 확보하기 위해서는 임계속도보다 큰 입구속도의 시용이 요구된다. The effectiveness of one dimensional critical velocity method for evacuation environment at 10MW fire size in a railroad tunnel have been investigated in this paper by three dimensional CFD method. It was performed to evaluate the evacuation environment in terms of temperature distribution, visible distance distribution and CO concentration at some tunnel inlet velocity, 1m/s, 2m/s (near critical velocity), and 3m/s. At all inlet velocity, passenger should give away downward the flow direction because the inlet velocity can not afford to sufficient evacuation environment for passengers. In case of 3m/s inlet velocity, however, the evacuation environment for passengers is better than the other cases. To provide more safe evacuation environment on fire situation, tunnel inlet velocity should be larger than critical velocity.

초음파 밀링 공정을 이용한 텅스텐 중합금 나노복합분말의 제조

이승철,이창우,정성수,차범하,이재성,Lee, Seung-Chul,Lee, Chang-Woo,Jung, Sung-Soo,Cha, Berm-Ha,Lee, Jai-Sung 한국분말야금학회 2007 한국분말재료학회지 (KPMI) Vol.14 No.2

Ultrasonic-milling of metal oxide nanopowders for the preparation of tungsten heavy alloys was investigated. Milling time was selected as a major process variable. XRD results of metal oxide nanopowders ultrasonic-milled for 50 h and 100 h showed that agglomerate size reduced with increasing milling time and there was no evidence of contamination or change of composition by impurities. It was found that nanocomposite powders reduced at $800^{\circ}C$ in a hydrogen atmosphere showed a chemical composition of 93.1W-4.9Ni-2.0Fe from EDS analysis. Hardness of sintered part using 50 h and 100 h powder samples was 399 Hv and 463 Hv, respectively, which is higher than the that of commercial products (330-340 Hv).

악성 림프종 환자에서 발생한 다형홍반

여운철,조광현,이유신,허대석,이승철 ( Un Cheol Yeo,Kwang Hyun Cho,Yoo Shin Lee,Dae Seog Heo,Seung Chul Lee ) 대한피부과학회 1990 대한피부과학회지 Vol.28 No.5

A Case of Erythema Multiforme A ssociated with Malignant Lymphoma Un Cheol Yeo, M.D., Kwang Hyun Cho, M.D., Yoo Shin Lee, M.D., Dae Seog Heo*, M.D., Seoung Chul Lee**, M.D Department of Dermatology and Internal Medicine*, College of Medicine, Seoul National University, Seoul, Korea, Department of Dermatology**, College of Medicine, Inha University, Kyung Gi Do, Korea We report a case of erythema multiforme associated with malignant lymphoma. Fifty-six-year-old male patient visited our clinic complaining generalized skin lesions which were compatible with erythema multiforme clinically and histopathologically. The skin lesions were treatment-resistant, recurrent and persistent for 3 years. In consideration of old age, atypical features of erythema multiforme and no other demonstrable etiology of erythema multiforme, we studied for internal malignancy. Malignant lymphoma at the duodenum was revealed by UGI series, abdominal CT, and endoscopic biopsy. After chemotherapy, the tumor mass and active skin lesions were cleared simultaneously. Erythema multiforme may be regarded as one of the paraneoplastic syndromes.

Fabrication of Tin(IV) Oxide Film by Sol-gel Method

이승철,이재호,김영환,Lee Seung-Chul,Lee Jae-Ho,Kim Young-Hwan The Korean Electrochemical Society 2000 한국전기화학회지 Vol.3 No.1

태양전지의 전극 기판으로 사용되는 전도성 투명 산화주석 박막의 제조 방법에 대하여 연구하였다. 졸겔법을 이용하여 산화 주석 박막을 제조하는 경우에 저가의 공정으로 대면적의 박막을 얻을 수 있는 장점이 있다. 본 연구에서는 공정 조건의 확립과 전구체의 설정에 중점을 두었다. 전구체 용액을 isopropyl 알코올에 tin isopropoxide를 용해한 용액을 사용하였으며 수화 반응을 억제하기 위하여 triethanolamine(TEA)을 첨가하였다. Corning유리 위에 spinning과 dipping방법을 이용하여 코팅을 하였으며 이후 열처리하여 최종 산화주석 박막을 제조하였다. 이렇게 제조된 박막은 가시광선 영역에서 $90\%$ 이상의 투과도를 보였으며 $0.01\Omega{\cdot}cm$ 이하의 비저항을 나타냈다 Transparent conducting tin (IV) oxide thin films have been studied and developed for the electrode materials of solar cell substrate. Fabrication of tin oxide thin films by sol-gel method is process development of lower cost photovoltaic solar cell system. The research is focused on the establishment of process conditions and development of precursor. The precursor solution was made of tin isopropoxide dissolved in isopropyl alcohol. The hydrolysis rate was controlled by addition of triethanolamine. Dip and spin coating technique were applied to coat tin oxide on borosilicate glass. The resistivity of the thin film was lower than 0.01-cm and the transmittance is higher than $90\%$ in a visible range.

도로터널 임계풍속 산정에 격자개수 및 화원의 크기와 위치가 미치는 영향

이승철,김상일,Lee, Seung-Chul,Kim, Sang-Il 한국터널지하공간학회 2012 한국터널지하공간학회논문집 Vol.14 No.3

본 연구에서는 도로터널 내 화재 시 임계풍속 산정을 위해 3차원 전산유체역학 기법을 이용하여 격자수, 그리고 화원의 크기와 위치에 따라 그 결과를 비교 분석하였다. 본 대상터널에서 1차원 식으로 산출된 임계풍속은 터널 높이 대신 수력지름을 적용한 경우 2.22 m/s로 산정되었다. 임계풍속 2.25 m/s를 적용하여 격자수에 따른 6가지 수치해석 결과, 격자수에 따라 역류의 위치와 온도, CO 농도 값이 상이하게 나타났으며, 본 대상터널의 경우는 약 84만개 격자수를 사용한 case 1이 적절한 격자임을 알 수 있었다. 또한 화원의 크기와 위치에 따른 수치해석 결과, 화원의 크기와 위치에 따라 상이한 기류분포, 온도분포 및 CO농도분포를 나타내어 임계풍속에 영향을 미친다는 것을 확인했다. 이것은 열교환 면적과 위치에 기인된다고 판단된다. 향후 실제 실험결과와 상세히 비교하여 3차원 수치해석의 격자 의존성과 화원의 위치 및 크기를 반드시 확인해야 할 것으로 판단된다. This study conducted comparative analysis to estimate critical velocity in tunnel fire under variation of grid number and the location and size of the fire source using three-dimensional computational fluid dynamics. In the target tunnel, by one-dimensional way, the calculated critical velocity in the tunnel, 2.22 m/s was estimated, if appling hydraulic diameter, instead of the tunnel height. According to six numerical analysis, each grid number has different position, temperature, and CO concentration of back-layering. In the case of the subject, the case 1 with 0.84 million grid was found to be the most ideal. According to the location and size of the fire source, after three cases for three-dimensional numerical analysis was performed, it is resulted that the location and size of the fire source affect the critical velocity, because air velocity distribution, temperature distribution and CO concentration distribution showed different each case. This is due to the difference of heat exchange area and locations. Therefore, it is necessary to decide appropriate grid number, and the location and size of the fire source for processing techniques through comparison with actual experiment results and three-dimensional analysis.

산소과다가 임신에 미치는 영향에 관한 실험적 연구

이승철,조수헌,안형식,윤덕로,Lee, Seung-Chul,Cho, Soo-Hun,Ahn, Hyeong-Sik,Yun, Dork-Ro 대한예방의학회 1989 Journal of Preventive Medicine and Public Health Vol.22 No.1

The adverse effect of diving on the fetus may extend beyond n gestational process and outcome. Primiparous Sprague-Dawley rats were assigned to one of ten exposure schedules during gestatred $PO_2$ level, the following question about the effect of exposing a pregnant female to high partial pressure of inspired oxygen has been raised. 'What effect does an increased maternal $PIO_2$ have on fetal arterial $PO_2$ and therefore on possible fetal oxygen poisoning?' This study was carried out to observe the effects of maternal hyperoxia on gestational process and outcome. Primiparous Sprague-Dawley rats were assigned to one of ten exposure schedules during gestation. The treatment groups were subjected to either the high concentration of oxygen, or the high atmospheric pressure. On day 21 of gestation, laparotomy was performed to examine for number and distribution of implantations and live and resorbing embryos. Fetuses were weighed, and examined for gross malformations. Subsequently, they were fixed, measured in physical parameters, and examined for visceral anomalies. Minor visceral anomalies and anatomical variation was not found. Similarily, there were no significant differences when number of resorptions, mean fetal weights, pregnancy interruption rate were compared by analysis of variance. These results indicate that exposing rats to oxygen at increased atmospheric pressure doese not affect fetal health or survival.

멀티 홉 통신을 기반한 화학 사고 대응 실시간 원격 모니터링 시스템

이승철,김남호,Lee, Seung-Chul,Kim, Nam-Ho 한국정보통신학회 2022 한국정보통신학회논문지 Vol.26 No.11

Recently, the safety of chemical substances has gained attention due to incidents occurring in petrochemical industrial complexes, such as gas leaks and fires. In particular, industrial complexes in Ulsan and Yeosu (South Korea) are valuable as they significantly contribute to the petrochemical industry, but accidents may occur due to chemical leakage. Therefore, in this study, sensor nodes are configured at an interval of 20 [m] based on outdoor facilities standards to respond to chemical accidents, and exposure consideration of 8 h (TWA) and 15 min (STEL) are proposed in TLVs. The proposed system pre-processes data collected in multi-hop communication at a cycle of 0.6-0.75 [s] using Python and stores it in the MySQL database through SQL and a real-time remote monitoring system that updates the stored data once every 5 s is implemented by linking MySQL and Grafana.

에탄의 산화성 탈수소화를 위한 Boron 산화물이 첨가된 알루미나 촉매의 최적 제조조건

이승철,유의연,선우창신 ( Seung Chul Lee,Eui Yeon Yu,Chang Shin Sunwoo ) 한국화학공학회 1995 화학공학의이론과응용 Vol.1 No.2