가시광에서 하이브리드 렌즈를 사용한 반사굴절식 전방위 줌 광학계의 설계 및 성능평가

박현식,조재흥,Park, Hyun Sik,Jo, Jae Heung 한국광학회 2020 한국광학회지 Vol.31 No.2

주간 무인 감시를 위하여 가시광 파장 범위인 400~700 nm에서 렌즈와 거울의 기능을 동시에 갖는 구멍 없는 하이브리드 렌즈를 활용한 반사굴절식 전방위 줌 광학계를 설계하고 그 성능을 분석하였다. 하이브리드 렌즈는 렌즈에 구멍을 뚫는 작업이 없고 광학 부품의 수량을 줄일 수 있기 때문에 전방위 줌 광학계의 제작과 조립에서 많은 장점을 갖는다. 이 광학계에서 결상된 도넛 형태의 상에서 안쪽의 압축된 낮은 공간주파수의 상 영역을 확대하여 보기 위해서 줌 렌즈의 기능을 추가한 전방위 광학계의 최적화 설계를 진행하였다. 그 결과 최적화 설계된 광학계의 변조전달함수, 스폿 다이어그램 분석, 공차 분석을 통해 이 광학계의 성능을 분석한 결과로부터 설계 목표 사양을 만족함을 알 수 있었다. 줌 광학계를 주밍할 때 -30~50℃의 온도 변화에 따른 비열화 해석을 한 결과, 적절한 렌즈의 재질을 선정하여 온도 변화에도 상 거리 변화가 거의 없는 광학계임을 확인하였다. A catadioptric omnidirectional zoom optical system using a hybrid lens (COZOSH) that performs simultaneously two functions of a lens and a mirror was designed at the visible wavelength range for daytime unmanned surveillance, and its performance was analyzed. The hybrid lens has lots of advantages in terms of fabrication and assembly of a COZOSH, because of the obviation of a lens boring process and reduction of the number of optical components. Additionally, we designed the COZOSH to expand the compressed inner-image region of a donut image at low spatial frequencies. As a result, the optimized design performance of the optical system that satisfies all initial design specifications was obtained from calculation of the modulation transfer function, spot diagram, and tolerance analysis. We confirmed that the COZOSH is a passively athermalized optical system under conditions of temperature variation from -30℃ to 50℃, by using athermalization analysis during zooming.

박막저항기 특성에 미치는 제조 공정 인자의 영향

박현식,유윤섭,Park Hyun-Sik,Yu Yun-Seop 한국마이크로전자및패키징학회 2005 마이크로전자 및 패키징학회지 Vol.12 No.1

저항 값을 맞추기 위한 트리밍 공정이 낮은 저항온도계수와 높은 정밀성을 요구하는 박막저항기 특성에 미치는 영향에 대한 연구가 수행되었다. 스퍼터링 방법으로 제조된 박막 저항기의 트리밍 속도에 따른 저항기의 특성 변화와 온도계수의 변화가 관찰되었다. 트리밍 속도의 증가에 따라서 박막 저항기 특성은 저하되었으며, 열처리로 저항 값의 평균 편차 $0.26\%$ 및 저항온도계수 52.77(ppm/K)의 개선효과가 있었다. 1k$\Omega$와 10k$\Omega$저항기가 100k$\Omega$ 박막저항기 보다는 특성이 양호하였으며, 트리밍 속도의 치적 조건으로는 20mm/sec와 특성 개선을 할 수 있는 최적 열처리 온도는 593K였으며 최적 조건에서 제작된 저항기의 저항 값의 평균 편차는 $0.31\%$ 및 저항온도계수 10(ppm/K)미만이었다. The effect of trimming process to adjust accurate resistance of a thin-film resistor was studied with respect to low temperature coefficient of resistance(TCR) and high precision. The characteristics of a thin-film resistor fabricated by sputtering were investigated depending on trimming condition and annealing temperature. Measured results showed that the characteristic of a thin-film resistor was degraded with increased trimming speed. However, an average resistance deviation and a TCR were improved to $0.26\%$ and 52.77[ppm/K], respectively, through annealing treatment. Also, thin-film resistors with 1 k$\Omega$ and 10k$\Omega$ showed better performance compared to a resistor with 100k$\Omega$. The Optimal trimming speed and annealing temperature were 20mm/sec and 539K, respectively, and under this optimal condition, a thin-film resistor with an average resistance deviation of $0.31\%$ and a TCR of below 10[ppm/K] was obtained.

비 카세트 방식과 카세트 방식을 이용한 [⁶⁸Ga]PSMA-11의 자동 합성 방법 비교

박현식,조병민,안현호,이홍진,이진형,이경재,이병철,이원우,Hyun-Sik, Park,Byeong-Min, Jo,Hyun-Ho, An,Hong-Jin, Lee,Jin-Hyeong, Lee,Gyeong-Jae, Lee,Byung-Chul, Lee,Won-Woo, Lee 대한핵의학기술학회 2022 핵의학 기술 Vol.26 No.2

Purpose [⁶⁸Ga]PSMA-11 is needed the high reproducibility, excellent radiochemical yield and purity. In term of radiation safety, the radiation exposure of operator for its production also should be considered. In this work, we performed a comparative study for the fully automated synthesis of [⁶⁸Ga]PSMA-11 between non-cassette type and cassette type. Materials and Methods Two different type of modules (TRACERlab FX N pro for non-cassette type and BIKBox for cassette type) were used for the automated production of [⁶⁸Ga]PSMA-11. According to the previously identified elution profile, Only 2.5 ml with high radioactivity was used for the reaction. After adjusting the pH of the reaction solution with HEPES buffer solution, the precursor was added and reacted with at 95 ℃ for 15 minutes. The reaction mixture was separated and purified using a C18 light cartridge. The product was eluted with 50% EtOH/saline solution and diluted with saline. It was completed by sterilizing filter. In the non-cassette type, the aforementioned process must be prepared directly. However, in the cassette method, synthesis was possible simply by installing a kit that was already completed. Results Both total [⁶⁸Ga]PSMA-11 production time were 25±3(non-cassette type) and 23±3 minutes(cassette type). The radiochemical yield of the non-cassette type(65.5±5.7%) was higher than that of the cassette type(61.6±4.8%) after sterilization filter. The non-cassette type took about 120 minutes of preparation time before synthesis due to washing of synthesizer and reagent preparation. However, since the cassette type does not require washing and reagent preparation, it took about 20 minutes to prepare before synthesis. Both type of synthesizer had a radiochemical high purity(>99%). Conclusion The non-cassette type production of [⁶⁸Ga]PSMA-11 showed higher radiochemical yield and lower cost than the cassette type. However, The cassette type has an advantage in terms of preparation time, convenience, and equipment maintenance.

고력황동의 Hard Spots 형성에 미치는 첨가원소의 영향

박현식,나형용 ( Hyun Sik Park,Hyung Yong Ra ) 한국주조공학회 1986 한국주조공학회지 Vol.6 No.1

This study was undertaken to understand the formation mechanism of the hard spots in high strength brass. To investigate the behavior of the hard spots in the isothermal liquid state with varying silicon content, the rapidly quenched specimens were obtained by suctioning the melt into the silica tube and water quenching. To examine the growth process of the hard spots with holding time, the unidirectional solidification technique was used. The results of this study are summarized as follows: 1) With the addition of Fe in order to get the effects of grain refinement in high strength brass, the two different type of Fe-rich phases are occurred, which are defined as dendritic and globular phase. The chemical composition of the globular phase was different from that of the dendritic phase in that the globular phase contained Si. 2) With increasing Si content, the Fe-rich phase had a tendency to form globular phase. 3) As the holding time increased in the liquid state, globular was also prone to coalesce. The further growth of globular phase to large size was due to reducing the interfacial energy. 4) The primary phase of copper alloy was nucleated preferentially on the dendritic phase. It was noticeable that the dendritic phase acted as a grain refiner. However, the agglomerate (hard spots) which was composed of the globular phase decreased the mechanical properties of high strength brass. 5) Once the hard spots formed in the high strength brass casting, it was very difficult to remove them. This is due to the fact that their meting temperature is higher than the pouring temperature of high strength brass.

Opalescence를 이용한 nightguard home bleaching

박현식 ( Hyun Sik Park ) , 김은성 ( Eun Sung Kim ) , 김문홍 ( Mun Hong Kim ) 조선대학교 구강생물학연구소 2003 Oral Biology Research (Oral Biol Res) Vol.27 No.2

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충청남도 예비노인의 경제적 노후준비 실태에 대한 탐색적 연구

박현식(Park, Hyun-Sik),이선형(Lee, Sun-Hyung),최은희(Choe, Eun-Hee) 한국지역사회복지학회 2010 한국지역사회복지학 Vol.0 No.35

본 연구는 대부분의 노인이 노후준비에 어려움을 겪고 있으며, 특히 농촌노인의 노후소득보장문제를 해결하기 위한 고민에서 시작되었다. 2008년 충청남도여성정책개발원에서 실시한 “충청남도 고령사회맞춤형 복지 5개년 계획수립”을 위한 55~64세의 예비노인을 대상으로 실시된 기초설문자료를 활용하였다. 이 연령집단은 65세 노인으로 진입하기 직전단계로 이들의 노후준비의 실태를 살펴보는 것은 향후 노후 소득보장을 살펴볼 수 있다. 충남노인의 노후준비를 살펴보기 위해 15개 시군의 노인인구비율별로 고령화지역(14% 미만), 고령지역(14~20%미만), 초고령지역(20%이상) 세 집단으로 구분하였으며 고령화지역의 159명, 고령지역의 198명, 초고령지역의 224명을 분석대상으로 하여 노후준비 실태를 살펴보았다. 그 결과 상당수의 예비노인들은 지역에 상관없이 노후준비를 하지 못하였으며 현재 생활이나 주관적 인식이 부정적인 것으로 나타났다. 노후준비를 하지 못한 가장 큰 이유는 경제적 여유가 없거나 하는 방법을 몰라서인 것으로 나타나 노후준비교육을 통한 노후준비 방법 습득은 예비노인의 노후준비문제를 개선시키도록 할 여지가 있는 것으로 여겨져 이의 교육에 대한 중요성이 부각되었다. 또한 초고령지역일수록 이에 관한 교육이나 상담을 받은 적이 없어 이러한 교육 및 상담기관을 확보하고 이에 대한 인력도 필요할 것으로 여겨진다. 노후준비와 관련한 일자리에 대한 질문에서는 지역별로 볼 때 고령화가 진전된 지역일수록 오랫동안 일할 의향을 보였으나 추가적인 소득을 위해 일할 의향은 고령화가 진전될수록 낮았다. 이는 앞에서 초고령지역의 노후대비 저축액이 타 지역에 비해 적었던 것을 감안한다면 일하고 싶은 의향은 적으나 노후대비가 충분치 않아 계속적으로 적은 소득으로도 일을 해야 할 가능성을 볼 수 있다. The main purpose of this paper is to explore the condition of financial preparation of the pre-elderly(age 55~64), especially focused on analyzing three groups according to the aging proportion of the area. The data is collected by interviewing 580 persons(age 55~64) living in the Chungcheongnam-do in 2008. As a result, the considerable pre-elderly have a unstable preparation condition and recognize negative their elderlyhood condition regardless of a aging proportion. And the most important reason is they don"t have enough money, and next one is they don"t know how to do well. So the issue of education for the pre-elderly about that has come to the fore, the most aged area have a the less opportunity to be educated. This means that the area has to expand the facilities and develop human resources to do it. And finally, in the job question, super-aged area respond the age of a retirement expectation is the last, but they don"t want to have a job for money and this reflects on their less financial preparations. It will needs to make an effort to be discussed in a welfare policy level.

일체형 원자로의 피동안전계통에 관한 열수력 검증시험 현황

박현식(Hyun-Sik Park),배황(Hwang Bae),류성욱(Sung-Uk Ryu),이성재(Sung-Jae Yi) 한국유체기계학회 2014 한국유체기계학회 학술대회 논문집 Vol.2014 No.11

온열환경분석을 통한 스틸하우스의 최적 지붕경사각 산출

박현식(Park.Hyun-sik),김현태(Kim.Hyun-tae),홍원화(Hong.Won-hwa) 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

The purpose of this study represents suitable slopes of a roof in steel houses and those of regarding thermal environment. Based on this, a paper has the purpose of using basic data to represent slopes of a roof in steel houses, which would be the most appropriate to the meteorological condition in Korea at the coming decades. The slopes of a roof in buildings are important factors relating to the amount of insulation. This insulation will also in fluence on building indoor thermal environment. Therefore, after calculating the amount of insulation by the angles of slopes we find all heat transmission and compare every value with each other. We select seven types as a study model according to slopes of a roof and choose a shed roof for a shape.

Hi-Lite(R)를 이용한 상악 변색치의 표백술

박현식 ( Hyun Sik Park ) , 정진호 ( Jin Ho Jeong ) , 김수미 ( Soo Mee Kim ) 조선대학교 구강생물학연구소 2003 Oral Biology Research (Oral Biol Res) Vol.27 No.1

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노인교육을 통한 선교방법의 탐색적 연구 : 교회성장을 중심으로

박현식(Park, Hyun-sik),김동주(Kim, Dong-joo) 한국기독교학회 선교신학회 2009 선교신학 Vol.22 No.-

This study is purposed to make sure that churches be responsible for elderly education, observe the level of educational needs of elders in order to activate elderly education within churches, prepare some appropriate programs for elders and consider some programs to improve elders’ social-cultural ability. Concretely considered, firstly, the theoretical basis should be considered through concerned documentary records. Secondly, the elders’ problems that are currently emerging as a serious social problem as aging society approaches should be studied in the aspect of elderly welfare. Thirdly, discussing what measures the churches can do to improve the elders’ welfare, this study introduced the elderly schools (or universities) that churches operate presently. Therefore, this study presents some programs to improve the elders’ welfare focused on the elders’ welfare programs of local communities and in the aspect of social-welfare, it approaches the elders’ problems and presents the elders’ welfare programs.