UV광 측정용 아조벤젠 코팅된 FBG의 열적 효과 제거 및 파장 의존성에 대한 연구

최동석,김현경,안태정,Choi, Dong-Seok,Kim, Hyun-Kyoung,Ahn, Tae-Jung 한국광학회 2011 한국광학회지 Vol.22 No.2

본 논문에서는 ultraviolet (UV) 광의 세기를 원격으로 측정하기 위한 아조벤젠 (azobenzene) 코팅된 fiber Bragg grating (FBG)를 구현하였다. 아조벤젠 폴리머는 UV 광에 의해서 탄성이 변화하여 FBG의 코어 격자의 주기 변화를 유도하여 중심파장을 이동시킨다. 중심파장의 이동은 UV 광과 UV 이외의 파장대역의 빛에 의해서 복합적으로 발생하는데 중심파장의 이동량은 약 0.18 nm 이다. 측정의 정확성을 향상시키기 위해서 광원의 복사열에 의한 중심파장의 이동을 열차단 필터(thermal filter)를 사용하여 제거한 결과 중심파장의 이동량은 약 0.06 nm로 다소 감소하였지만 분석 결과 열에 의한 이동량이 충분히 제거된 것을 확인하였다. 또한 서로 다른 방법인 열경화법과 UV 경화법으로 각각 제작된 아조벤젠 폴리머를 이용하여 아조벤젠 코팅 FBG를 제작하였고, 각 제조법에 따른 UV센서로서의 적합성을 확인하였다. 몇 개의 밴드패스 필터(band pass filter)를 사용하여 파장에 대한 민감도를 측정한 결과, 단위 UV 세기당 중심파장의 이동량은 370nm 파장 밴드에서 가장 큰 값인 0.029로, 단파장 영역에서 반응성이 우수하다는 사실을 확인 하였다. 아조벤젠 폴리머의 흡수 스펙트럼과 아조벤젠 코팅 FBG의 파장 의존도가 서로 잘 일치하는 것을 확인하였다. In the paper, we have demonstrated an azobenzene-coated fiber Bragg grating (FBG) for monitoring ultraviolet light (UV) intensity in remote measurement. The elasticity of the coated azobenzene polymer is changed by the UV light, which induces a center wavelength change corresponding to the change of the FBG's grating period. The wavelength shift resulting from both UV light and other light with the wavelength out of the UV range was about 0.18 nm. In order to improve the accuracy of the measurement, the center wavelength shift caused by radiant heat of the light source was sufficiently removed by using a thermal filter. The amount of the center wavelength shift was consequently reduced to 0.06 nm, compared to the result without the thermal filter. Also, the FBGs coated by using azobenzene polymer were produced by two different methods; thermal casting and UV curing. Considering temperature dependence, UV curing is more suitable than thermal casting in UV sensor application of the azobenzene-coated FBG. In addition, we have confirmed the wavelength dependence of the optical sensor by means of four different band pass filters. Thus, we found out that the center wavelength shift per unit intensity is 0.029 [arb. unit] as a maximum value at 370 nm wavelength region and that the absorption spectrum of the azobenzene polymer was very consistent with the wavelength dependence of the azobenzene-coated FBG.

와류형 고압인젝터의 초기분무의 분열 과도현상

최동석,김덕줄,고장권,Choi, Dong-Seok,Kim, Duck-Jool,Ko, Chang-Kwon 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.8

The disintegration process of initial spray from high-pressure swirl injector was investigated at different injection pressures. The transient breakup phenomena that were difficult to observe at high injection pressure were easily observed at the low injection pressure of 0.4MPa. The effect of fuel remained inside a nozzle hole volume on the penetration of initial spray was also investigated. The disintegration process of initial spray could be classified four regions: the formation of mushroom shape, the first collision, the second collision, and the development of spray, The liquid film of cup shape was particularly found in the second collision region, and the growth ratio of its length and width at low and high injection pressures were compared.

와류형 고압 분무의 속도 및 입경분포에 관한 연구

최동석,류경훈,차건종,김덕줄,Choi, Dong-Seok,Ryu, Kyung-Hoon,Cha, Keun-Jong,Kim, Duck-Jool 대한기계학회 1999 大韓機械學會論文集B Vol.23 No.10

High-pressure swirl injectors have usually been employed in Gasoline direct injection engines due to their spray characteristics and the feasibility of their control. Thus the microscopic characteristics of high-pressure swirl spray were investigated by PDA. The correlation between axial and radial velocities and the correlation between droplet size and axial velocity were examined with different axial and radial positions. Two dimensional droplet velocity and its number distribution with size-classified droplets were illustrated. The mean droplet velocity and its SMD were also analyzed at the center of spray, the position having maximum mean axial velocity, and the spray periphery using time dividing method. Finally, the structure of high-pressure swirl spray was presented with the size distribution and velocity profile of droplets.

묵자(墨子)의 하늘의 뜻(天志)과 보편적인 사랑(兼愛)의 상관관계 연구

최동석(Dong-Seok CHOI) 대구가톨릭대학교 가톨릭사상연구소 2020 가톨릭사상 Vol.- No.60

묵자는 하늘의 뜻과 보편적인 사랑을 주장하였다. 하늘은 마치 인격을 지닌 사람처럼 그 뜻을 밝히고 있는데, 묵자는 당시 통치자들에게 올바른 정치와 옳지 않은 정치의 구분을 말해주고 싶었던 것이다. 그의 관념 속의 하늘의 뜻은 상나라의 하늘관념에서 온 것으로, 하늘은 자연의 이치뿐만 아니라, 인간이 살아가는 지상의 모든 것을 주재하였다. 묵자는 큰 나라가 작은 나라를 침공하는 침략전쟁을 반대하였다. 그 이유는 하늘이 바라지 않기 때문이다. 하늘은 보편성을 두루 갖추어 세상의 모든 가치를 부여하는 기준이 되기 때문에 통치자들은 하늘의 뜻을 두루살필 것을 제창하였다. 묵자가 말하는 하늘의 뜻은 ‘사람들이 서로 사랑하고 서로 이롭게 하기’를 원하지 ‘사람들이 서로 미워하고 서로 해하는 것은 원하지 않는다’는 것이다. 한 걸음 더 나아가 하늘은 그 의지를 분명히 세상에 천명하였는데, 그것은 바로 천하의 백성을 ‘차별 없이 사랑하고’, ‘하늘을 존중하며 많은 사람들을 이롭게 하는 자’에게는 반드시 복을 내린다는 점이다. 묵자는 하늘의 뜻에 따른다는 것은 ‘천하의 사람들을 보편적으로 사랑하는 일’이라고 주장하는데 이것은 다름 아닌 ‘보편적 사랑’을 말하는 것이었다. 묵자 사상의 핵심근본이라고 말할 수 있는 ‘보편적 사랑’이야말로 약육강식의 시대를 멈출 수 있는 유일한 방법인 것이다. 묵자는 보편적인 사랑이 필연적으로 침략전쟁에 대한 비판 이론으로 전개된다는 것을 피력했다. 죄 없는 사람이 죽어가는 것은 하늘의 뜻이 아니다. 침략전쟁의 결과는 영원한 승자가 없이 힘없는 백성들만 희생당하는 것이다. 전쟁은 하늘을 저버리는 행위이다. 묵자는 보편적인 사랑의 실천만이 평화를 이룰 수 있다는 것을 세상에 외친 것이다. 묵자가 말하는 ‘보편적인 사랑’의 근거는 결국 모든 사람을 똑같이 감싸주고, 모든 사람에게 똑같이 먹여주며, 모든 사람들이 서로 돕고, 서로 가르치며, 재물이 있으면 서로 나누어주기를 바라는 ‘하늘의 뜻’이다. Mozi speak of Heaven’s intention. This is arguably one of the two most important of Mozi’s doctrines along with Universal Love. He continued the idea of Shang Di in the Shang dynasty. Mozi thought Heaven is the supreme arbiter and controller of human affairs. Mozi opposed the war of aggression in which a great nation attacked a small country. he said, ‘The Heaven’s intention abominates the large state which attacks small states, the large house which molests small houses, the strong who plunder the weak, the clever who deceive the stupid, and the honoured who disdain the humble, these are what the will of Heaven abominates.’ The meaning of Heaven’s intention that Mozi says is that everybody in the world loves universally, taking them for themselves. Heaven’s intention is to bring people to the practice of universal love. ‘Universal love’ is the only way to stop the law of the jungle. Mozi emphasized, what is the will of Heaven that is to be obeyed? It is to love all the people in the world universally. Universal love he says is the way to follow the will of heaven.

코팅 형태에 따른 아조벤젠 코팅 FBG 자외선 센서의 특성 연구

최동석 ( Dong Seok Choi ),정회석 ( Hoe Seok Jeong ),김찬영 ( Chan Young Kim ),송일신 ( Il Shin Song ),김현경 ( Hyun Kyoung Kim ),안태정 ( Tae Jung Ahn ) 조선대학교 공학기술연구원 2012 공학기술논문지 Vol.5 No.2

In this study, we have characterized a ultraviolet (UV) sensor based on a fiber Bragg grating (FBG) coated with azobenzene-containing polymer material. The elasticity of the azobenzene polymer as a photo-responsive material that undergoes reversible refractive index change on exposure to ultraviolet light, which induces the center wavelength shift corresponding to the variation of the azobenzene-coated FBG`s period. In comparison with thermal casting method and UV curing method to polymerize the functional material, it turns out that UV curing method is more suitable than thermal curing method for the UV sensors. We prepared an azo-coated FBG attached on slide-glass and made by a homemade Teflon mold. It was found out that azo-coated FBG fabricated by using the Teflon mold is more suitable than the other method for the UV sensors. In order to confirm the reproducibility and reliability of the proposed UV sensor, we repeatedly tested the UV-induced response of the sensor at 60 times for 120 minute.

스페이스 마케팅의 집객적 요소를 적용한 국내 프리미엄 식품관 공간계획에 관한 연구

최동석(Choi, Dong-Seok),윤은경(Yun, Yean-Kyung) 한국실내디자인학회 2016 한국실내디자인학회 학술대회논문집 Vol.2016 No.10

South Korea’s Food hall in the past was focused on adjusting criteria of consumers to the choice of products and functions of the quality. However, as the structure of population, social, economic, and cultural changes occur, consumers’ various styles of consumption started to rise. And, in accordance, the age has changed to where consumers purchase products with value that suits their psychological, emotional state, and lifestyle. Accordingly, in addition to the premium products, premium Food hall is stimulating sensibility by providing experience has came in to the world. However, although many of the premium Food halls have set the slogan emphasizing consumer’s lifestyle and experience to, consumer’s degree of experience is at the paltry level. In this paper, by recognizing a need of new marketing techniques for consumers to feel experience and knowledge by having interactive relationship in space, it presents premium Food hall by applying strategic technique, Space Marketing.

구동용 전동기의 출력특성에 대한 안전기준 부합성시험에 대한 연구

최동석(Dong-Seok Choi),박용성(Yongsung Park),이광범(Kwangbum Lee),권해붕(Haeboung Kwon),용기중(Geejoong Yong) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

Compliance tests of electric motors for vehicle driving were performed to characterize power performance of the motors. Two different e-motors were used for testing the net power and the maximum 30 minutes power. One is a synchronous permanent magnet motor with water cooling. The other is an asynchronous induction motor with air cooling. According to the Korean safety regulation, electric power analysis was conducted and the temperature inside the motors was measured. It was found that temperature limit in each part was very important control factor and the speed or the torque control mode has to be selected as the type of the motors to be tested. Maximum 30 minutes power could be considered as the representative power of the motors.

ETC모드에서의 Urea SCR 시스템 성능특성

최동석(Dong-Seok Choi),박용성(Yongsung Park),김남용(Namyong Kim),정혁(Hyuk Jung),이정기(Junggi Lee),권해붕(Hae-Boung Kwon),김용우(Yongwoo Kim),김성환(Sunghwan Kim),이성호(Seongho Lee),함윤영(Yunyoung Ham) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

사이렌 및 수소혼합분위기에서 글로우방전 분해법에 의해 제조된 비정질 실리콘의 광특성

최동석(Dong-Seok Choi),박기철(Ki-Chul Park),박창배(Chang-Bae Park),김기완(Ki-Wan Kim) 대한전자공학회 1986 대한전자공학회 학술대회 Vol.1986 No.6

중생(衆生)의 번뇌(煩惱)와 근본장애(根本障碍)에 대한 일고찰 -『능가경(楞伽經)』을 중심으로-

최동석 ( Dong Seok Choi ) 대구가톨릭대학교 인문과학연구소 2013 인문과학연구 Vol.0 No.19

What is unavoidable in the lives of Sattva is klesa(evil passions). Klesa brings about suffering, which is linked to death. The Buddhists claim that deaths are not the end, and what you did in the past becomes karma and leads to cycles of life, Then why does klesa occur? In addition, after klesa take place, what obscurations are people confronted? The questions would be discussed in this paper. The foundational Sutra selected for the research is four fascicles of Lankaυatara Sutra. As it is in line with the beginning of the Zen Buddhism in China, the book four fascicles of Lankauatara Sutra holds more important position than other translated sutra in the early history of Chinese Zen buddhism. Klesa is the beginning of fundamental problems that prevent people from seeing as it is. Klesa is caused by ignorance and desire, which also invite karma. With Ciyate(accumulated) karrna in our Citta(mind), the activity consciousness from what happened in the past affects us in the present, keeping our consciousness from seeing what is happening before our very eyes correctly. As a result, we distinguish and judge based on parikalpita(imagination) things like imagination and dreams formed by paratantra(reality). That is why we insist only ‘I’ am the right. This paper looks into the causes of klesa, the cycle and penomenon of life and death of citta(Vijnana), and the consequent fundamental obscurations of Sattva, that is, parikalpita and paratantra. When we do not know of the interconnected process, pain ends only as pain, But once we know, we realize that mind is origin of the triple world. That is when yogin begins.