A Quantitative A naly sis of the Fire Hazard Generated from Hydrogen Fuel Cell Electric Vehicles

Sungwook Kang(Sungwook Kang),Kyu Min Lee(Kyu Min Lee),Minjae Kwon(Minjae Kwon),Ohk Kun Lim(Ohk Kun Lim),Joung Yoon Choi(Joung Yoon Choi) 한국화재소방학회 2022 International Journal of Fire Science and Engineer Vol.36 No.2

There is a lack of information on (i) the potential fire load of new green-technology vehicles, (ii) flame spread behavior, (iii) thermal impacts on high-pressure hydrogen storage vessels (HSVs) and lithium-ion batteries (LIBs) during fuel cell electric vehicles fires (FCEVs), and (iv) thermal damage to adjacent vehicles and upper structural members during FCEV fires occurring in civil structures, such as underground spaces, multi-story parks, and tunnels. In view of this, a full-scale fire test was conducted in this study to quantitatively assess the fire risk of hydrogen FCEVs. Large-scale cone calorimetry was used to quantify the thermal intensity released from the FCEV fire. The flame spreading behavior through an FCEV with HSVs and LIBs was observed using the thermocouples installed. Changes in the temperature and irradiance around the FCEV fire were also measured using an instrumented test rig. The peak heat release rate, total heat released, and fire growth rate were observed to be 5.99 MW, 11.8 GJ, and 0.0055 kW/s², respectively. The temporal point of hydrogen gas release from the HSVs' thermal pressure relief device (TPRD) was estimated to be 16.2-26.2 min. The initiation of thermal runaway of LIBs was deduced from the temperature-time profiles of the LIB modules and their metal housing approximately 22.2 min after HCEV ignition. Moreover, FCEV fires could thermally impair adjacent upper structural members by 800 ℃ combustion gas for at least 13 min and emit a median heat flux of 27.2 kW/m² (peak heat flux of 76.5 kW/m²) to adjacent vehicles. The measurements and findings obtained from this study can contribute to the evaluation of and further studies on newly emerging fire hazards.

저산소성 허혈성 뇌손상을 유발시킨 어린 백서에서 Myeloperoxidase 측정 검사

양혜정(Hae Joung Yang),피대훈(Dae Hun Pee),임지혜(Ji Hye Lim),최병민(Byung Min Choi),이기형(Kee Hyoung Lee),은백린(Baik-Lin Eun) 대한소아신경학회 2002 대한소아신경학회지 Vol.10 No.2

목 적 : 예전에는 뇌경색 부위에서 발견되는 백혈구를 단지 뇌손상에 뒤따르는 생리적인 반응으로만 생각하였으나 최근 10년 사이 재관류 손상에서도 백혈구에 의한 염증 작용이 중요한 역할을 한다고 알려지면서 이들의 역할에 대한 연구가 새롭게 이루어지고 있다. PML의 존재는 세포질내 과립에서 분비되는 MPO를 생화학적으로 측정함으로서 증명할 수 있는데 저자들은 미성숙 뇌에서 저산소성 허혈증에 의한 뇌손상이 발생할 때 백혈구가 침윤되는 과정을 MPO 측정 검사를 통하여 관찰하였고, P와 L-selectin 억제제인 Fucoidin을 투여한 후 MPO의 변화를 확인하였다. 방 법 : 생후 7일된 어린 흰쥐를 사용하여 우측총 경동맥을 전기 응고시켜 자르고 8% 산소에 노출시켰다. 저산소 노출 후 회복 시간에 따라 동물을 희생시키고 뇌를 추출하여 뇌조직 1 g당 10mL의 20 mM potassium Phosphate buffer(pH 7.4)를 첨가하여 50초간 분쇄하였다. 각각의 균질회된 조직 샘플들은 4℃에서 20분 동안 원심 분리하여 상층액을 제거한 후, 침전물은 처음 조직량에 따라 조직 1 g당 10 mL의 0.5% cetylditrimethylethyl ammonium bromide(wt/vol)가 첨가된 50 mM potassium phosphate buffer(pH 6.0)를 첨가하였다. Vortex를 이용하여 buffer와 침전물을 잘 섞고 60℃수조에서 120분 동안 방치하였다. 그 후 각 조직 샘플들을 4 watts에서 음파처리하고 4℃에서 15분 동안 원심 분리를 시행하여 상층액을 새로운 tube에 옮겼다. MPO 측정검사를 위한 MPO reaction buffer는 50 mM potassium phosphate buffer(pH 6.0) 100 mL에 0.53 mM odianisidine edihydrochlorde와 0.0005% HO를 섞어 만들었다. MPO reaction solution 2.9 mL에 각각의 MPO sample 0.1 mL을 첨가하여 460 nm의 파장에서 5분 동안 MPO에 다른 흡광도 차이를 관찰하였다. 결 과 : 조직내 백혈구 침윤의 지표로 측정한 MPO 활성도는 대조군에서는 미미하였으나 총 경동백을 절단한 우측 대뇌군에서는 허혈 및 저산소증 유발 후 8시간째부터 현저히 증가되기 시작하여 24시간 경과 후 발현이 가장 높았으며, Fucoidin 50 mg/kg으로 전처치한 약물 실험군에서는 MPO 활성도가 현저히 감소하였다. 결 론 : 백혈구는 미성숙 뇌의 저산소성 허혈증에 의한 뇌손상에서 중요한 매개체 역할을 하며, 백혈구의 생화학적 활성도를 나타내는 MPO 활성도는 저산소성 허혈성 뇌손상의 정도를 측정하는 지표로 이용될 수 있다고 생각된다. Purpose : Neutrophils found around an infarcted area in the brain was once considered as only the physiologic response following the brain injury, but recent studies have shown that inflammatory responses by neutrophils play an important role in the reperfusion injury. The presence of ploymorphonuclear leukocytes(PML) is proven by biochemical assay of myeloperoxidase(MPO) Secreted in the cytoplasmic granules. We observed the process of PML infiltration on hypoxic-ischemic brain injury of immature rats by the assay of MPO activity and changes of the MPO activity after the administration of fucoidin, inhibitor of P- and L-selectin. Methods : We used a well characterized model of the brains of 7 day-old-rats, which had unilateral hypoxic and ischemic injuries(HI). Those injuries were induced by unilateral carotid artery ligation followed by timed exposure to hypoxic inspiratory gas mixture(8% O). MPO activity was measured in the brain tissue homogenates of HI rats(n=18) at 0, 2, 8, 24 and 48 hrs and in rats that received fucoidin immediately before and again after hypoxia(50 mg/kg, n=6) at 8 and 24 hrs. Controls(n=2) were rats with neither hypoxia nor ischemia. The brain samples were homogenized in 20 mM potassium phosphate buffer(pH 7.4) for 50 secs. The homogenate was centrifuged at 14,000 g at 4℃ for 15 mins and the supernatant was discarded. The tissue was pulverized, weighed, and suspended in 1 mL of 50 mM potassium phosphate buffer solution(pH 6.0) contatining 0.5% cetylditrimethylammonium bromide(wt/vol). The tissue was sonicated and centrifuged at 10,000 g for 15 mins. 200 µL of the supernatant was mixed with 1 mL of 50 mM potassium phosphate buffer solution(pH 6.0) containing 10 μL of 1.325 mM o-dianisidine hydrochloride and 170 µL of 3% hydrogen peroxide(vol/vol). Changes in absorbance at 460 nm were measured for 5 mins by using microplate reader. One unit of MPO activity was defined as that degrading 1 µmol peroxide/min at 25℃, and the result was expressed as units of MPO/100 gm tissue. Results : In HI rats, MPO activity increased at 2 hrs after HI and peaked at 24 hrs in the right hemisphere. In rats with fucoidin treatment immediately before and again after hypoxia, the MPO activity significantly decreased in both hemispheres compared with HI rats(P<0.05). MPO activity in the tissue of control rats was insignificant. Conclusion : The dynamic changes of the MPO activity suggest the important role of PMN on hypoxic-ischemic brain injuries in immature rats. MPO activity could be used as an index of the severity of injuries of hypoxic-ischemic brains.

이차함수에서 두 변량사이의 관계 인식 및 표현의 발달 과정 분석: 민선의 경우를 중심으로

이동근 ( Dong Gun Lee ),문민정 ( Min Joung Moon ),신재홍 ( Jaehong Shin ) 한국수학교육학회 2015 수학교육 Vol.54 No.4

The aim of this qualitative case study is twofold: 1) to analyze how an eleventh-grader, Min-Seon, conceive and represent a pattern of change between two varying quantities in a quadratic functional situation, and 2) further to help her form a concept of ``derivative`` as a tool to express the relationship with employing a concept of ``rate of change.`` The result indicates that Min-Seon was able to construct graphs of piecewise functions that take average rates of change as range of the functions, and managed to conjecture the derivative of a quadratic function, y=x ^{2}. In conclusion, we argue that covariational approach could not only facilitate students`` construction of an initial function concept, but also support their understanding of the concept of ``derivative.``

도심 수목원에서의 경관감상과 산책이 인체의 생리적 안정에 미치는 영향

박범진 ( Bum Jin Park ),가재남 ( Jae Nam Ka ),이민선 ( Min Sun Lee ),김선아 ( Seon A Kim ),박민우 ( Min Woo Park ),최윤호 ( Yoon Ho Choi ),정다워 ( Da Wou Joung ),권치원 ( Chi Weon Kwon ),염동걸 ( Dong Geol Yeom ),박순주 ( Soon Jo 한국산림과학회 2014 한국산림과학회지 Vol.103 No.4

This research was conducted to investigate the impact of viewing scenery and walking in the urban forest onphysiological relaxation of humans. The experiment was conducted in Hanbat Arboretum located in Daejeon, and thecontrol experiment was conducted in front of Daejeon City Hall. The subjects that participated in the experimentcomprised 24 Korean male university students in their 20s (average age, 21.1±2.5 years), participated in the experimentas the subject, and these subjects were classified into three groups divided into three locations such as the pine forest inArboretum, the pond in Arboretum, and the city. The subjects sat down and viewed scenery for 10 min, and they thenwalked for 15 min. Further, physiological changes were measured using indicators such as heart rate variability (HRV),blood pressure, and pulse rate. As a result, when subjects viewed scenery and walked in the urban forest, a statisticallysignificant increase in the high frequency (HF) power of HRV and decrease in systolic pressure was observed comparedwith when subjects viewed scenery and walked in the city. Through this research, it was found that activities like viewingscenery or walking in Arboretum of the city are effective in increasing the physiological relaxation of the city residents.

Fast running FIR filter를 이용한 적응잡음 제거기에 대한 연구

이채욱,정민수,이재균 대구대학교 2005 대구대학교 학술논문집 Vol.1 No.1

본 논문에서는 적응 신호처리의 수렴속도를 향상 시키고 복잡한 계산량을 줄이는 효율적인 fast running FIR 필터 구조를 제안한다. 그리고 제안한 알고리즘을 웨이블렛 기반 적응 알고리즘에 적용한다. 실제로 합성 음성을 사용하여 적응 잡음 제거기에 적용하여 컴퓨터 시뮬레이션을 통해 제안한 알고리즘과 기존 알고리즘과의 성능을 비교한다. 그 결과 변환 영역 알고리즘은 기존의 시간영역의 알고리즘보다 수렴속도의 향상을 보였고 웨이블렛 알고리즘과 short-length fast running FIR 알고리즘보다 제안한 fast-short-length fast running FIR 알고리즘을 사용함으로 계산 량이 줄어드는 것을 확인하였다. In this paper, we propose a new fast running FIR filter structure that improves the convergence speed of adaptive signal process and reduces computational complexity. The proposed filter is applied to wavelet based adaptive algorithm. Actually we compared the performance of the proposed algorithm with other algorithm using computer simulation of adaptive noise canceler based on synthesis speech. As the result, the frequency domain algorithm is prefer than the existent time domain. We known that the proposed fast running FIR algorithm reduces the computations.

근로자 건강증진전략을 위한 행동변화에 대한 요구도 평가

이강숙,임현우,구정완,홍현숙,이정민,이원철,박정일,맹광호,M, O'Donnel 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : In order to evaluate the stage of behavior change for health promotion strategy in workplace Methods : Questionnaire survey was carried out for 309 workers who employed in H Electronics company in Kyong-in area from September to October 1998. Results : According to need assessment of four step such as precontemplation stage, contemplation stage, action stage, maintenance stage which were to change of behavior for health promotion, the percent for quitting smoking were observed 48.8%, 43.1%, 8.1%, 0%, and for the restriction of drinking were 29.8%, 10.6%, 9.3%, 5.3%; for fitness 11.1%, 31.0%, 37.3%, 20.6% in male 26.6%, 27.8%, 26.6%, 19.0% in female, for regular diet 26.1%, 19.8%, 38.7%, 15.3% in male, 27.8%, 22.2%, 40.0%, 10.0% in female and for stress management 5.8%, 10.6%, 8.7%, 75.0% in male, 13.6%, 22.7%, 19.7%, 44.0% in female. In heavy smoker(p=0.017) and heavy drinker,(p=0.021) the percent of precontemplation stage was significantly higher than in lower drinker and light smoker. Conclusions : This study suggested that company support for health promotion in workplace was and workers of high risk group for smoking and drinking were in precontemplation stage. So before conducting the health promotion program, health risk appraisal and need assessment for stage of behavior change should be taken for the efficient health promotion strategy.

한국영화에 나타난 스모키 메이크업에 관한 연구 : 2000년~2007년 개봉 영화를 중심으로

이윤선,이정민 한국메이크업디자인학회 2008 한국메이크업디자인학회지 Vol.4 No.1

This study examines the smoky make-up trend of each color used for image creation of the main characters in Korean movies form 2000 to 2007. For the study method, I used the movie specializing sites, preceding papers, various books and internet sites. 'Flower Island' of 2000 shows eternity and mystery, despair and death, darkness and depression with the use of black smoky make-up. 'No Blood, No Tears' of 2002 shows the significance of inhibiting the movement of emotions in glamour, solemnity, elegance and nobility through dark purple smoky make-up. 'Butterfly' of 2003 reveals the organizational and fixed characteristics but at the same time shows stability, simplicity and honesty with brown smoky make-up. 'Faceless Beauty' of 2004 declines the energy and source of life or deny rationality and shows the death and decay of nature through brown smoky make-up. 'Sympathy for Lady Vengeance' of 2005 plays the role of increasing stimulation, anxiety and tension with red smoky make-up; however, at the same time, it is the color of life and love. 'The Customer is Always Right' of 2006 has the significance of calm, natural, motherly love and dependency through brown smoky make-up. ' Open City' of 2007 has the tendency of showing brightness and freshness, on the other hand, when there are many colors it becomes frivolous showing jealousy and extravagance with gold smoky makeup. As a result of analyzing smoky make-up method of each movies in 2000s, the many characters of femme fatale used the smoky make-up.

조선시대 궁중가례와 화장에 관한 연구

이정원,이정민 한국메이크업디자인학회 2007 한국메이크업디자인학회지 Vol.3 No.3

This study is about the wedding feast and make-up of royal court at Joseon dynasty era. Joseon dynasty era is not only the most active era in are as such as culture. ideology and art. but also the era when the modem style of traditional Korean costumes is established. 'Gungjung Garae' is the wedding feast of a king who represents a country, and a cultural asset which represents the ceremonies and costume of Joseon dynasty era. In this study, the process, costume and make-up of the wedding feast of royal court are surveyed, and books and prior studies about these have been referred to for this study. First, Joseon dynasty announces a command which prohibits people from being married for a while. Then the candidates for the queen are selected by the first, second and third evaluation processes. Then, in the process of the wedding feast are Napchae, Napjing, Gogi, Chaekbi, Bong young and Dongroe. Second, for the main ceremony of the wedding feast, the king puts on the imperial crown and a black-colored costume called as Myonbok which is composed of Jungdan, Sang, Eui, Daedae, Pyesuel, Hyukdae. Paeok, Soo, Mal, Suk, Cyoo, and Bang-sim-gok-ryoung. The queen puts on a red-colored costume which is embroidered by pheasant, and composed of Jungdan, Hapi, Naeui. Sang, Pyesuel, Daedae, Hyukdae, Paeok, Soo, Mal, Suk and Gyoo. Third, as the queen's make-up for the main ceremony, her face is made up and painted with face powder and Yeonji, and this process is called as 'Sungieok' in Joseon dyanasty era. The A shaped hair style at the feast is called as 'Daesu meori' on top of Jjokrmmmeori and decorated with sevearl yongbinyuoe(dragon shaped ornamental hairpins ), Ddeol-jam and many accessories. The objective of this study is that the results of this study contribute to the inducement of more interests to Korean tradition and culture, and the development and inheritance of our tradition with pride.

현대 메이크업에 나타난 고스 스타일에 관한 연구

이정민 한국메이크업디자인학회 2008 한국메이크업디자인학회지 Vol.4 No.1

Make-up now became an area to create newness by leading a sense of the times, trends, ideas and creativity through pursuing newness of human body breaking away from materials in various methods according to themes, as one of important methods to express ourselves containing human being's aesthetic instinct and ceaseless desire. In particular, make-up trends that were introduced in collections after the latter half of 1990s show indefiniteness of expression and free subjective expression and aesthetic value overcoming the concept of the existing traditional beauty. Goth style that is called 'new gothic' of medieval style has newly appeared in the 21st century. Goth style tried to enter popular culture while appearing as trends for fashion and make-up at fashion collections. Accordingly, the current study aimed to examine how characteristics of goth style were reflected on make-up and analyze types of goth make-up and characteristics. For the study, literature style was conducted using relevant books both home and abroad, various materials and prior papers. Also expressive patterns of goth image in modern make-up were analyzed using photos in fashion magazines and related websites for demonstrative analysis.

공침법에 의한 Y₁-_(x)Ca_(x)Ba₂Cu₃O_(7-8)분말의 제조

정민교,박병춘,이완재 한양대학교 이학기술연구소 2002 이학기술연구지 Vol.5 No.-

Y₁_(x)Ca_(x)Ba₂Cu₃O_(7-8) powder was synthesized by a coprecipitation method. This process is very easy to control the chemistry of the cation's solutions and coprecipitation with oxalic acid. Starting materials Of nitrates such Y(NO₃)₂ · 6H₂0, Ca(NO₃)₂ · 4H₂0, Ba(NO₃)₂and Cu(NO₃)₂ · xH₂O were dissolved into distilled water. Each solution was mixed and pH-controlled with oxalic acid The best condition of coprecipitation was pH 1.3 at room temperature. The yield of precursor was up to 92%. After calcining at 850℃ in air, 123 single phase was obtained. The size of 123 phase powder was about 90nm.