RF 마그네트론 스퍼터링 방법을 이용한 ZnO 가스센서의 암모니아 검지특성

최우창,최혁환,이명교,권태하 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

The ammonia gas sensors were fabricated with the ZnO-based thin films grown by a RF magnetron sputtering method in various sputtering gas atmosphere and substrate temperature. We investigated the sensitivity to ammonia gas concentration and working temperature. The sensors of thin films grown in oxygen sputtering gas showed higher sensitivity than those grown in argon sputtering gas. The sensors with ZnO-based thin film doped with MoO_(3)(0.875 wt.%) showed the maximum sensitivity of 70 at a working temperature of 250 ℃ and to ammonia gas of 160 ppm.

열처리에 따른 Pb[(Zr,Sn)Ti]N$bO_3$ 박막의 강유전 특성

최우창,최혁환,이명교,권태하,Choe, U-Chang,Choe, Hyeok-Hwan,Lee, Myeong-Gyo,Gwon, Tae-Ha 대한전자공학회 2001 電子工學會論文誌-SD (Semiconductor and devices) Vol.38 No.7

강유전 물질인 Pb/sub 0.99/[(Zr/sub 0/6Sn/sub 0.4/)/0.9/Ti/sub 0.1/]0.98/Nb/sub 0.02/O₃(PNZST) 박막을 10 mole%의 과잉 PbO가 첨가된 타겟을 이용하여 La/sub 0.5/Sr/sub 0.5/CoO₃(LSCO)/Pt/Ti/SiO₂/Si 기판상에 RF 마그네트론 스퍼터링 방법으로 증착하였다. 증착된 박막에 대하여 온도와 시간을 다양하게 변화시키면서 급속 열처리(rapid thermal annealing) 한 후, 그 결정성과 전기적 특성을 조사하였다. 80 W의 RF 전력, 500 ℃의 기판온도에서 증착한 후, 급속 열처리된 박막이 페로브스카이트상으로 결정화되었으며, 650 ℃, 공기중에서 10초동안 급속 열처리된 박막이 가장 우수한 결정성을 나타내었다. 이러한 박막으로 제작된 PNZST 커패시터는 약 20 μC/㎠정도의 잔류 분극과 약 50 kV/cm 정도의 항전계를 나타내었으며, 2.2×10/sup 9/의 스위칭 후에도 잔류분극의 감소는 10 %미만이었다. Ferroelectric P $b_{0.99}$[(Z $r_{0}$ 6S $n_{0.4}$)/0.9/ $Ti_{0.1}$]0.98/N $b_{0.02}$ $O_3$(PNZST) thin films were deposited by a RF magnetron sputtering on L $a_{0.5}$S $r_{0.5}$Co $O_3$(LSCO)/Pt/Ti/ $SiO_2$/Si substrate using a PNZST target with excess PbO of 10 mole%. The crystallinity and electrical properties of the thin films annealed at various temperature and time were investigated. The thin films deposited at the substrate temperature of 500 $^{\circ}C$ and the power of 80 W were crystallized to a perovskite phase after rapid thermal annealing(RTA). The thin films annealed at 650 $^{\circ}C$ for 10 seconds in air exhibited the good crystal structures. The remanent polarization and coercive field of the PNZST capacitor were about 20 $\mu$C/$\textrm{cm}^2$ and 50 kV/cm, respectively. The reduction of the polarization after 2.2$\times$10$^{9}$ switching cycles was less than 10 %..10 %......

수평유동장에서 난류증진을 위한 초음파 적용에 관한 연구

최우창,박영호,송민근,주은선 경상대학교 생산기술연구소 2000 生産技術硏究所論文集 Vol.16 No.-

A study on the application of ultrasonic vibration for the turbulence enhancement in a horizontal flow field was carried out by laying emphasis of the Reynolds numberand the ultrasonic incidence angle on the laminar flow field. A large water tank was made of the transparent acrylic plates and city water of 25℃ was used as working fluid. Angles of the ultrasonic oscillator such as 30°, 45° , 60° , 90° , 120° , 135° and 150° were selected and experiments for the above were made. Data, such as time mean velocity vector and time mean turbulent intensity which was obtained by PIV measurement, were examined, compared and discussed at Reynolds No. 2,000 and 4,000 to know the degree of turbulence enhancement in each case.

가치부여와 마음 씀

최우창 대한철학회 2023 哲學硏究 Vol.167 No.-

Often we try to understand what others are like by referrimg to what they value. Some people commit their whole life to what they value and some sacrifice themselves for it. Indeed, what we value turns out to be an important consideration in either deciding what to do or planning how to live. This paper aims to provide an analysis of valuing as such. Firstly, two preceding analyses by David Lewis and Michael Smith respectively, will be examined and declined. Then, an exposition of Harry Frankfurt's conception of caring will be presented. In conclusion, it will be argued that the concept of caring so construed and the concept of valuing capture the same type of mental state. 우리는 종종 타인이 무엇에 가치 부여하는가, 혹은 무엇을 가치 있게 여기는가를 보고 그 사람에 대한 배경 이해를 형성한다. 누군가는 자신이 가치 있게 여기는 것을 위해 삶을 헌신하기도 하고 또 누군가는 목숨을 바치기도 한다. 이처럼 무언가를 가치 있게 여긴다는 것은 우리가 타인을 이해할 때에도, 우리가 우리 자신의 삶을 어떤 방향으로 이끌어 갈 것인가 하는 문제에도 중요한 고려사항이 된다. 본 논문의 목표는 위와 같은 의미에서 어떤 것을 가치 있게 여긴다는 것(valuing)이 무엇인지에 대해 분석하는 것이다. 이를 위해 본 논문에서는 우선 데이빗 루이스(David Lewis)와 마이클 스미스(Michael Smith)의 선행연구를 검토하고 그들의 이론이 성공적이지 못한다는 것을 지적한다. 그 후 해리 프랭크퍼트(Harry Frankfurt)의 마음 씀(caring) 개념을 분석하고 마음 씀과 가치 있게 여김은 동일한 유형의 마음 상태를 포착하는 개념이라는 것을 보이고자 한다.

1개 기관 보건직 공무원의 조직문화인식이 직무만족도에 미치는 영향

최우창,강성욱,정성화 한국보건정보통계학회 2013 보건정보통계학회지 Vol.38 No.1

Objectives: The aims of this study were to examine the perceived organizational culture and job satisfaction and to determine the factors associated with job satisfaction among a public health officials. Methods: A total of 321 subjects (160 men and 161 women) conveniently selected from 1,460 public officials working at the Ministry of Food and Drug Safety (MFDS). The survey was conducted by selfadministered questionnaire which consisted of perceived organizational culture, job satisfaction, and socio- demographic and job-related characteristics. Univariate and multivariate analyses were performed to determine an association between perceived organizational culture and job satisfaction using SPSS 18.0. Results: The 40.8% of respondents perceived that the organizational culture of MFDS was a clan type, whereas only 6.2% perceived it was an adhocracy type. The mean of job satisfaction was 3.46. Moreover, those who felt the culture was adhocracy recorded the highest levels of job satisfaction. The workers who perceived their organizational culture was market or hierarchy were more discontent than those who perceived theirs was clan after adjusting for socio-demographic and job-related characteristics. Conclusions: It is desirable to transform the organizational culture at MFDS into one of clan or adhocracy type.

우울증상에 대한 심리척도의 유용성에 대한 기초연구-비우울증, 화병과의 비교를 중심으로-

최우창,김나현,최승원,정인철 대한한방신경정신과학회 2013 동의신경정신과학회지 Vol.24 No.4

Objectives: The purpose of this study is to investigate the usefulness of psychological measurements in depression symptoms as compared with non-depressions and hwabyung.Methods: A total of 21 patients, who were diagnosed with depression and hwabyung, were evaluated by using the SCL-90-R, BDI, STAI, STAXI, ISI, HRSD, 20-Item Alexithymia Scale, BSDS and NEO-PI. Thereafter, they were statistically analyzed.Results: 1) In the results of SCL-90-R, the PST score group of hwa-byung group without depression was significantly higher when compared to the score from the depression group without hwa-byung. 2) In the results of NEO-PI, the NEO-PI-O score of hwa-byung group without depression was sig-nificantly higher when compared to the score from the depression group without hwa-byung. 3) In the results of 20-Item Alexithymia Scale, the total score and score of difficulty for identifying feelings scale from the depression group was significantly higher when compared to the score of non depression group. Conclusions: The results found are expected to serve as a useful resource for future studies when de-veloping the instruments of oriental medical evaluations for hwa-byung.

ZnO 박막 센서의 암모니아 가스 검지 특성

최우창,김성우,류지열,박성현,최혁환,이명교,권태하 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

The ammonia gas sensors were fabricated with the ZnO-based thin films grown by a RF magnetron sputtering method. We investigated the sensitivity and response time according to temperature variation and ammonia gas concentration. The sensors sputtered in oxygen atmosphere showed higher sensitivity than those sputtered in argon atmosphere. The Au(0.3 wt.%) doped-ZnO thin film sensors aged at 330 ℃ showed the maximum sensitivity of 28 and good response time at a working temperature of 250 ℃ and to 160 ppm ammonia gas. The Pt(0.1 wt.%) doped-ZnO thin film sensors showed the maximum sensitivity at a low working temperature of 200 ℃.

Structural and Dielectric Properties of Pb[(Zr,Sn)Ti]NbO3 Thin Films Deposited by Radio Frequency Magnetron Sputtering

최우창 한국전기전자재료학회 2010 Transactions on Electrical and Electronic Material Vol.11 No.4

Pb0.99[(Zr0.6Sn0.4)0.9Ti0.1]0.98Nb0.02O3 (PNZST) thin films were deposited by radio frequency magnetron sputtering on a (La0.5Sr0.5)CoO3 (LSCO)/Pt/Ti/SiO2/Si substrate using a PNZST target with an excess PbO of 10 mole%. The thin films deposited at the substrate temperature of 500°C crystallized to a perovskite phase after rapid thermal annealing (RTA). The thin films, which annealed at 650°C for 10 seconds in air, exhibited good crystal structures and ferroelectric properties. The remanent polarization and coercive field of the fabricated PNZST capacitor were approximately 20 uC/cm2 and 50 kV/cm, respectively. The reduction of the polarization after 2.2 × 109 switching cycles was less than10%.

가족과 함께한 식목행사

최우창 숲과 문화 연구회 2005 숲과 문화 Vol.14 No.3

조성비에 따른 Pb[(Zr,Sn)Ti]NbO3 박막의 강유전 특성

최우창,최혁환,이명교,권태하 한국센서학회 2002 센서학회지 Vol.11 No.1

Ferroelectric Pb0.99[(Zr0.6Sn0.4)1-xTix]0.98Nb0.02O3(PNZST) thin films were deposited by a RF magnetron sputtering on (La0.5Sr0.5)CoO3(LSCO)/Pt/Ti/SiO2/Si substrate using a PNZST target with excess PbO of 10 mole%. The crystallinity and electrical properties of the thin films with various composition ratio were investigated. The thin films deposited at the substrate temperature of 500 and the power of 80 W were crystallized to a perovskite phase after rapid thermal annealing(RTA) at 650 for 10 seconds in air. A PNZST thin films with Ti of 10 mole% showed the good crystallinity and ferroelectric properties. The remanent polarization and coercive field of the PNZST capacitor were about 20 C/cm2 and 50 kV/cm, respectively. The reduction of the polarization after 2.2 109 switching cycles was less than 10 %. 강유전 물질인 Pb0.99[(Zr0.6Sn0.4)1-xTix]0.98Nb0.02O3(PNZST) 박막을 10 mole%의 과잉 PbO가 첨가된 타겟을 이용하여 La0.5Sr0.5CoO3(LSCO)/Pt/Ti/SiO2/Si 기판상에 RF 마그네트론 스퍼터링 방법으로 증착하였다. Ti의 조성비를 변화시키면서 증착된 박막에 대하여 그 결정성과 전기적 특성을 조사하였다. 80 W의 RF 전력, 500 의 기판온도에서 증착한 후, 650 , 공기중에서 10초동안 급속 열처리된 박막이 가장 우수한 페로브스카이트상으로 결정화되었다. 또한, Ti의 조성비가 10 mole%를 가지는 PNZST이 가장 우수한 결정성과 강유전 특성을 나타내었다. 이러한 박막으로 제작된 PNZST 커패시터는 약 20 C/cm2정도의 잔류분극과 약 50 kV/cm 정도의 항전계를 나타내었으며, 2.2 109의 스위칭 후에도 잔류분극의 감소는 10 % 미만이었다.