경남지역 근대한옥의 안채 평면특성에 관한 연구

최규철,이호열,Choi, Gyu-Cheol,Lee, Ho-Yeol 한국건축역사학회 2006 건축역사연구 Vol.15 No.2

7층 적층구조 배면발광 청색 OLED의 발광 특성 연구

최규철,김덕열,장상목,Gyu Cheol Choi,Duck-Youl Kim,SangMok Chang 한국청정기술학회 2023 청정기술 Vol.29 No.4

최근 많은 정보를 신속하게 전달하기위한 방법으로 디스플레이의 역할은 아주 중요하며 다양한 색을 자연색에 가깝게 재현하기 위한 연구가 진행 중이다. 특히 정확하고 풍부한 색을 표현하기 위한 방법으로 발광 구조에 대한 연구가 진행되고 있다. 기술의 고도화, 디바이스의 소형화로 인해 작지만 높은 시인성과 에너지 소모에서 높은 효율을 가진 디스플레이의 필요성이 지속적으로 증가되고 있는 실정이다. OLED의 효율을 향상시키기 위해서는 운반자 주입의 향상, 전자와 정공이 수적인 균형을 이루며 효율적으로 재결합 할 수 있는 소자의 구조, 발광 효율이 큰 물질의 개발 등 OLED의 효율을 향상시키고자 하는 노력은 다방면에서 진행되고 있다. 본 연구에서는 7층 적층구조 배면발광 청색 OLED 소자의 전기적 특성 및 광학적 특성을 분석하였다. 소자는 제작이 용이하며, 고효율 및 고휘도화가 가능한 Blue 발광물질인 4,4'-Bis(carbazol-9-yl)biphenyl : Ir(difppy)2(pic)를 사용하였다. OLED 소자 제작은 SUNICEL PLUS 200 시스템을 이용하여 5×10-8 Torr 이하의 고진공 상태에서 In-Situ 방식으로 증착하였다. Electron or Hole Injection Layer(EIL or HIL) Electron or Hole Transport Layer(ETL or HTL) 등이 추가된 5층 구조에 Electron or Hole Blocking Layer(EBL or HBL)을 추가한 7층 구조로 실험을 진행하였다. 제작한 소자의 전기적, 광학적 특성을 분석한 결과 EBL 층과 HBL층을 삽입하여 색의 확산을 방지한 소자는 색 순도가 우수하게 나타났다. 본 연구결과를 이용하여 청색 OLED 디스플레이 소자의 연구 개발 기초 및 실용화에 크게 기여할 것으로 기대된다. Recently, displays play an important role in quickly delivering a lot of information. Research is underway to reproduce various colors close to natural colors. In particular, research is being conducted on the light emitting structure of displays as a method of expressing accurate and rich colors. Due to the advancement of technology and the miniaturization of devices, the need for small but high visibility displays with high efficiency in energy consumption continues to increase. Efforts are being made in various ways to improve OLED efficiency, such as improving carrier injection, structuring devices that can efficiently recombine electrons and holes in a numerical balance, and developing materials with high luminous efficiency. In this study, the electrical and optical properties of the seven-layer stacked structure rear-light emitting blue OLED device were analyzed. 4,4'-Bis(carazol-9-yl)biphenyl:Ir(difppy)2(pic), a blue light emitting material that is easy to manufacture and can be highly efficient and brightened, was used. OLED device manufacturing was performed via the in-situ method in a high vacuum state of 5×10-8 Torr or less using a Sunicel Plus 200 system. The experiment was conducted with a seven-layer structure in which an electron or hole blocking layer (EBL or HBL) was added to a five-layer structure in which an electron or hole injection layer (EIL or HIL) or an electron or hole transport layer (ETL or HTL) was added. Analysis of the electrical and optical properties showed that the device that prevented color diffusion by inserting an EBL layer and a HBL layer showed excellent color purity. The results of this study are expected to greatly contribute to the R&D foundation and practical use of blue OLED display devices.

고전압 전력반도체 소자 개발을 위한 단위공정에서 식각공정과 이온주입공정의 영향 분석

최규철,김경범,김봉환,김종민,장상목,Gyu Cheol Choi,KyungBeom Kim,Bonghwan Kim,Jong Min Kim,SangMok Chang 한국청정기술학회 2023 청정기술 Vol.29 No.4

파워반도체는 전력의 변환, 변압, 분배 및 전력제어 등을 감당하는데 사용되는 반도체이다. 최근 세계적으로 고전압 파워반도체의 수요는 다양한 산업분야에 걸쳐 증가하고 있는 추세이며 해당 산업에서는 고전압 IGBT 부품의 최적화 연구가 절실한 상황이다. 고전압 IGBT개발을 위해서 wafer의 저항값 설정과 주요 단위공정의 최적화가 완성칩의 전기적특성에 큰 변수가 되며 높은 항복전압(breakdown voltage) 지지를 위한 공정 및 최적화 기술 확보가 중요하다. 식각공정은 포토리소그래피공정에서 마스크회로의 패턴을 wafer에 옮기고, 감광막의 하부에 있는 불필요한부분을 제거하는 공정이고, 이온주입공정은 반도체의 제조공정 중 열확산기술과 더불어 웨이퍼 기판내부로 불순물을 주입하여 일정한 전도성을 갖게 하는 과정이다. 본 연구에서는 IGBT의 3.3 kV 항복전압을 지지하는 ring 구조형성의 중요한 공정인 field ring 식각실험에서 건식식각과 습식식각을 조절해 4가지 조건으로 나누어 분석하고 항복전압확보를 위한 안정적인 바디junction 깊이형성을 최적화하기 위하여 TEG 설계를 기초로 field ring 이온주입공정을 4가지 조건으로 나누어 분석한 결과 식각공정에서 습식 식각 1스텝 방식이 공정 및 작업 효율성 측면에서 유리하며 링패턴 이온주입조건은 도핑농도 9.0E13과 에너지 120 keV로, p-이온주입 조건은 도핑농도 6.5E13과 에너지 80 keV로, p+ 이온주입 조건은 도핑농도 3.0E15와 에너지 160 keV로 최적화할 수 있었다. Power semiconductors are semiconductors used for power conversion, transformation, distribution, and control. Recently, the global demand for high-voltage power semiconductors is increasing across various industrial fields, and optimization research on high-voltage IGBT components is urgently needed in these industries. For high-voltage IGBT development, setting the resistance value of the wafer and optimizing key unit processes are major variables in the electrical characteristics of the finished chip. Furthermore, the securing process and optimization of the technology to support high breakdown voltage is also important. Etching is a process of transferring the pattern of the mask circuit in the photolithography process to the wafer and removing unnecessary parts at the bottom of the photoresist film. Ion implantation is a process of injecting impurities along with thermal diffusion technology into the wafer substrate during the semiconductor manufacturing process. This process helps achieve a certain conductivity. In this study, dry etching and wet etching were controlled during field ring etching, which is an important process for forming a ring structure that supports the 3.3 kV breakdown voltage of IGBT, in order to analyze four conditions and form a stable body junction depth to secure the breakdown voltage. The field ring ion implantation process was optimized based on the TEG design by dividing it into four conditions. The wet etching 1-step method was advantageous in terms of process and work efficiency, and the ring pattern ion implantation conditions showed a doping concentration of 9.0E13 and an energy of 120 keV. The p-ion implantation conditions were optimized at a doping concentration of 6.5E13 and an energy of 80 keV, and the p+ ion implantation conditions were optimized at a doping concentration of 3.0E15 and an energy of 160 keV.

소화기 증상을 동반한 만성두통 환자에 대한 한방복합치료 치험 1례

최규철,배지은,박재원,김동진,홍정수,Choi, Gyu-cheol,Bae, Ji-eun,Park, Jae-won,Kim, Dong-jin,Hong, Jeong-su 대한한방내과학회 2021 大韓韓方內科學會誌 Vol.42 No.5

Objectives: The purpose of this study was to examine the effect of combined Korean medical treatment on chronic headache with digestive symptoms. Methods: We collected data from October to December 2020 and evaluated the efficacy of combined Korean medical treatment using the Korean Headache Impact Test-g (KHIT-6), European Quality of Life Five Dimensions (EQ5D) Scale, and Numerical Rating Scale (NRS) at admission, after two weeks of hospitalization, and on discharge. Results: At the end of treatment, the patient had increased EQ5D and reduced KHIT-6 and NRS scores. Conclusions: After the combined Korean medical treatment, the patient showed improvement, suggesting the efficacy of treatment.

DED 기반 적층/절삭 하이브리드 가공 기술을 이용한 스프로켓 보수 공정 개발

최규철(K. C. Choi),김두리(D. R. Kim),심아진(A. J. Sim),장진수(J. S. Jang),이강재(K. J. Lee) Korean Society for Precision Engineering 2022 한국정밀공학회 학술발표대회 논문집 Vol.2022 No.10

레이저 적층공정의 산화물 제어 및 인장특성 연구

최규철(K. C. Choi),문창규(C. K. Moon),도진호(J. H. Do) Korean Society for Precision Engineering 2018 한국정밀공학회 학술발표대회 논문집 Vol.2018 No.10월

개인의 배경적 특성에 따른 어촌체험휴양마을 선호도 분석

최규철 ( Choi Kyuchul ),김정태 ( Kim Jungtae ),이서구 ( Lee Seogu ),강동선 ( Kang Dongseon ) 한국농공학회 2021 한국농공학회논문집 Vol.63 No.2

The purpose of this study is to analysis the influence of personal backgrounds on the preference of fishing village experience recreation villages. As the analysis method, binary logistic regression analysis was used. Dependent variables are experience recreation villages (rural and fishing). The independent variables consist of 9 groups of people: gender, age, family type, marital status, presence of children, principal companion, fishing village image, visit experience villages, recognition of fishing village experience recreation village. As a result of the analysis, it was found that the tourist’s gender, age, family type, marital status, presence of children, principal companion, fishing village image, visit experience villages, recognition of fishing village experience recreation village influence the preference of fishing village experience recreation village. By characteristics of each group, it was found that male prefer fishing village experience recreation villages 1.597 times as much as female, and those with a positive image about fishing villages prefer fishing village experience recreation villages as much as 2.644 times than those with negative images. In addition, it was found that those who visited the fishing village experience and recreation village prefer the fishing village experience village about six times more than those who have never visited.

급성 심근경색증 환자의 병원내원시간 지연에 관련된 요인

최규철(Choi, Kyu-Chul),최성수(Choi, Seong-Su) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.2

급성심근경색환자에서 증상발병후 병원도착지연이 질병과 사망률에 중요한 관련이 있다. 이 연구에서는 환자 의 증상 인식 등 응급의료체계 활성화 이전 단계의 의료기관 내원 지연의 원인을 연구하여, 향후 내원지연 시간 감소 를 위해 적절한 보건교육 및 치료의 방향을 찾고자 하였다. 연구 샘플은 2009년 6월에서 9월까지 급성심근경색으로 입원한 환자를 대상으로 하였다. 인구통계, 의료기록 및 임상자료는 병원진료기록를 이용하였으며, 병원전 지연은 6시 간이전과 이후로 분류하였다. 급성심근경색증 환자들에서 내원시간 지연에 영향을 미치는 요인으로는 고령인 경우, 낮은 사회경제적 위치, 응급의료체계의 이용하지 않고 내원 한 경우와 급성심근경색을 위한 응급처치의 지연등이다. 따라서 사회경제적 위치가 낮은 계층과 고령층에 대한 급성관상동맥 증후군의 증상에 대한 지식을 높이고 증상발생 시 의료기관을 빠르게 이용하도록 교육이 필요하다. In patients with acute myocardial infarction (AMI), the delay from symptom onset to hospital arrival has a critical effect on morbidity and mortality. This study examined to find out the determinants of the prehospital delay in patients with AMI. The study sample consisted of 597 patients hospitalized with AMI between Jan and Dec 2009. Demographic, medical history, and clinical data were abstracted from the hospital medical records of patients with confirmed AMI, the prehospital delay was categorized as less than or greater than 6 hours. Older age, low socioeconomic status(medical aid), and low use of Emergency medical system were associated with delays in seeking emergency care for Acute myocardial infarction. Education programs to improve patient knowledge of acute coronary syndrome symptoms and promote patient responsiveness with regard to seeking medical care should be used to reduce the prehospital delay time, especially in the low socioeconomic group.

피부의 상피세포 종양에서 TGFα , EGF 및 EGF Receptor 발현에 관한 면역조직화학적 연구

최규철(Kyu Chul Choi),윤영곤(Young Kon Yoon),오창남(Chang Nam Oh) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.3

Background : Seversl reporte have demonstrated that TGFa and EGF are mitogenic for keratinocytes. Whether its expressian on epithelial tumors is a marker of malgnancy or signifies an important step in the development of neoplasia is poorly understood. EGF receptors are also present in normal epidermis and epithelial tumors but their physiological roles are not yet understood. Objective : Our purpose was to examine the staining patterns of TGFa, EGF and EGF receptors on the epithelial tumors of the skin., and to investigate the kinetics of expresion of EGF receptors. Methods : We performed immunoperoxidase staining(ABC technique with monoclonal anti-TGFa antibody, polyclonal anti-EGF hntibody and polyclonal anti-EGF recepfor antibody on the formalin-fixed, paraffin-embedded tissue specimens of benign, premalignant and melignant skin tumors. Results : The density of the eixpression of TGFa and EGF was not or elated with the degree of the malignancy of the epithelial tumors and is neither constant in any kind of the tumors. However the infiltrative type of basal cell carcinoma(BCC) is stronger than its solid type on the expression of TGFa and EGF. All benign tumors demonstrated a diffusevattern within tumor lobules. Focal TGFe immunostaining were seen in three of 10 squamous cell carinomas(SCC) and four of 10 BCCs. TGFa immunostaining wias absent from the outermost one to two layers of tumor lobules of all keratoacanthomas. The specimens which increased the expression of TGFc and EGF tended to decrease the expression of EGF receptor. Conclusion : These data suggest that the density of immunohistocherrical expression of TGFa and EGF may be not dependent on the differentiation of tumor cells, and the pattern of immunohistochemical expression of TGFa can differentiate SCC from benign tumors sueh is keratoacanthoma. EGF receptor may be occupied by both of TGFa and EGF. With the receptor bring occupied a down regulation of the receptors may occur which results in decreased EGF receptor expression. (Kor J Dermatol 1994; 32(3): 438-445)

STS316L 3D 프린팅 적층물의 열처리 효과 분석 연구

최규철(K. C. Choi),문창규(C. K. Moon),도진호(J. H. Do),이동목(D. M. Lee) Korean Society for Precision Engineering 2019 한국정밀공학회 학술발표대회 논문집 Vol.2019 No.5월