화학적 공정을 이용한 Y₂Ti₂O₇ 분말과 후막 제조 및 특성

이원준,최연빈,배동식,Lee, Won-Joon,Choi, Yeon-Bin,Bae, Dong-Sik 한국재료학회 2017 한국재료학회지 Vol.27 No.5

$Y_2Ti_2O_7$ nanoparticles (0.3 mol%) have been successfully synthesized by the co-precipitation process. The samples, adjusted to pH7 with ammonia solution as catalyst and calcined at $700{\sim}900^{\circ}C$, exhibit very fine particles with close to spherical shape and average size of 10-30 nm. It was possible to control the size of the synthesized $Y_2Ti_2O_7$ particles by manipulating the conditions. The $Y_2Ti_2O_7$ nanoparticles were coated on a glass substrate by a dipping coating process with inorganic binder. The $Y_2Ti_2O_7$ solution coated on the glass substrate had excellent adhesion of 5B; pencil hardness test results indicated an excellent hardness of 6H. The thickness of the thick film was about $30{\mu}m$. Decomposition of MB on the $Y_2Ti_2O_7$ thin film shows that the photocatalytic properties were excellent.

Johanson 방법을 응용한 연령추정

이원준,김병국,김재형,임회순,이금숙,최홍란,Lee, Won-Joon,Kim, Byung-Gook,Kim, Jae-Hyung,Lim, Hoi-Soon,Lee, Guem-Sug,Choi, Hong-Ran 대한안면통증구강내과학회 2005 Journal of Oral Medicine and Pain Vol.30 No.2

Age estimation is fundamental and important in personal identification with forensic medicine and dentistry. Recently, a lot of studies using various part of the body have been done for age estimation. Age estimation with teeth is the most significant method comparing ones with other part of the body. Gustafson method and Johanson method using postmortem teeth have been authorized in accuracy and systemization and used domestically and internationally. The verification of the accuracy in above methods had been tried many times but it is still rare in Korea. Fifty-nine teeth(incisors, canine, premolars and molars) which were extracted due to periodontal diseases or orthodontic problem were collected. Present study is to 1) compare the accuracy of estimated age in applying Gustafson method and Johanson method to the teeth in Korea, 2) compare and analyze the correlation with results using Gustafson method and Johanson method by age, gender, maxilla - mandible and anterior - premolar - molar. Teeth were embedded in resin and sliced and then examined each one using Gustafson method and Johanson method. The results are as follows: 1. Actual age was a significant difference in estimated age by Johanson method. Actual age was a significant correlation in estimated age by Gustafson method and modified Johanson method. Modified Johanson method was more significant than Gustafson method. 2. In estimated age by Gustafson method, Johanson method and modified Johanson method, there was no significance with actual age by location and gender. 3. In estimated age by Gustafson method, Johanson method and modified Johanson method, there was significance with actual age by age group. Finally, Gustafson method and Johanson method can be used in Korea. To make more accurate verification, however, it needs more specimen and postmortem teeth. Johanson equation proposed by himself has to be developed by further studies.

판재 점진 성형 공정의 정밀도 향상을 위한 다이 구조 개선에 대한 연구

이원준,김민석,선민호,유제형,이창환,LEE, Won-Joon,KIM, Min-Seok,Seon, Min-Ho,YU, ․Jae-Hyeong,Lee, Chang-Whan 한국금형공학회 2022 한국금형공학회지 Vol.16 No.2

Unlike other press forming processes, ISF (Incremental sheet forming) doesn't require a punch and die set. However, during the ISF processes unwanted bending deformation occurred around the target geometry. This paper is aimed to analyze the effect of the die structure, which is supported by bolts, on the geometric accuracy of the ISF processes. In this research, the ISF processes with Al5052 sheet of 0.5 mm, the tool diameter of 6 mm and the stepdown of 0.4 mm was employed. L-shaped, step-shaped, relief-shaped geometry were employed in experiments. Sectional view and the plastic strain were compared. From this research we find out that the bolt supported ISF processes increases the geometric accuracy of products very effectively.

Effects of Sleep Habits on EEG Sensory Motor Rhythm in Female College Students

Won-Joon Lee(이원준),Hyun-Ju Choi(최현주) 한국생명과학회 2012 생명과학회지 Vol.22 No.5

본 연구의 목적은 수면장애가 뇌파(EEG)의 beta파와 감각운동리듬(sensory motor rhythm)에 미치는 영향을 규명하는 것이다. 여자 대학생을 대상으로 하여 수면습관에 따라서 다음과 같이 네 군(n=6)으로 나누었다. 즉, 좋은 수면습관을 가진 GSHG (Good sleep habit group), 일반적으로 대학생들이 늦게 취침하는 수면 습관을 갖고 있기 때문에 오전 0~2시에 취침하는 CSHG (Common sleep habit group), 수면위상지연증후군으로 자신의 수면장애를 인식하고 있는 CSDG (Cognitive sleep disorder with delayed sleep phase syndrome group), 수면장애를 인식하지 못하는 NSDG (Non-cognitive sleep disorder with delayed sleep phase syndrome group)으로 나누었다. 뇌파는 QEEG 8-System을 사용하여 오전 9~12시 사이에 측정하였다. 책읽기 자극시에 뇌파를 측정하여 안정시 기준치와 비교 분석하였다. 연구 결과, 책읽기 자극시 beta파와 감각운동리듬 상대파워는 GSHG가 다른 세군에 비하여 유의적으로 높았다(p<0.05). 책읽기 자극시 수치와 안정시 기준치를 대응 비교하여 볼 때에도, GSHG에서 beta 파워가 대뇌피질의 모든 부위에서 유의적으로 증가하였다(p<0.05). 그러나 CSHG에서는 전두부와 측두부에서 beta 파워가 감소하였다(p<0.05). 한편 CSDG와 NSDG에서는 책읽기 자극에 의하여 beta 파워의 유의적인 변화가 발생하지 않았다. 감각운동리듬 상대파워는 GSHG에서만 책읽기 자극에 의하여 향상되었다. 결론적으로 여자 대학생에게 있어서 오전 0~2시경에 늦게 취침을 하면 다음날 오전에 집중력 뇌파인 beta파 기능이 현저히 감소하고, 수면습관이 나쁘면 자신의 수면장애에 대한 자가인식 유무와 관련 없이 beta파와 운동감각리듬에 대한 뇌기능이 활성화되지 않아서 집중력에 부정적인 영향을 준다. To evaluate the effects of sleep habits on the powers of beta waves and the sensory motor rhythm of the electroencephalogram (EEG), female college student subjects were divided into four groups, according to their sleep habits, as follows: GSHG (Good Sleep Habit Group), CSHG (Common Sleep Habit Group: late bedtime), CSDG (Cognitive Sleep Disorder-Delayed Sleep Phase Syndrome Group), and NSDG (Non-cognitive Sleep Disorder-Delayed Sleep Phase Syndrome Group). Brain function was stimulated by reading a book for 3 min in the morning (9~12 am) and the EEG was measured. According to the results, the powers of the beta waves and sensory motor rhythm were not different during the resting period among the four groups. However, during the reading stimulation period, the powers of beta waves and the sensory motor rhythm in the GSHG were significantly greater than in the other groups (p<0.05). Beta powers during stimulation also increased in all brain areas in the GSHG (p<0.05). Interestingly, these were decreased in the frontal and temporal lobes in the CSHG by the reading stimulation (p<0.05). On the other hand, sensory motor rhythm, which represents focusing efficacy, only improved in the GSHG. These results indicate that the brain’s focusing function during the reading stimulation was not properly operating in the morning in the female college students who had a delayed bedtime and bad sleep habits.

보건계열 대학생의 일반 수면습관 및 지연된 수면위상과 수면의 질, 주간졸림증, 우울 및 스트레스와의 상관관계

이원준(Won Joon Lee) 한국콘텐츠학회 2023 한국콘텐츠학회논문지 Vol.23 No.7

본 연구는 대학생의 일반 수면습관 및 지연된 수면위상이 수면의 질, 주간졸림증, 우울 및 스트레스와 어떤 상관관계를 가지는가를 규명하기 위하여 시도되었다. 경상도 지역에 소재한 2개 대학의 보건계열 학과 학생들 122명으로부터 온라인 설문 조사를 통하여 자료를 수집하였으며, SPSS 23.0을 사용하여 분석하였다. 분석결과 일반 수면습관 중 평일 평균 기상시각은 평일 평균 수면시간과 평일 평균 취침시각은 평일 평균 수면시간, 평일 평균 기상시각 및 성별과 주말 평균 기상시각은 평일 평균 수면시간, 주말 평균 수면시간, 평일 평균 기상시각, 평일 평균 취침시각과, 주말 평균 취침시각은 평일 평균 수면시간, 평일 평균 기상시각, 평일평균 취침시각, 주말평균 기상시각과 상관관계를 가지고 있었다. 수면의 질과 주간졸림증은 스트레스 및 우울과 상관관계가 있었고 스트레스는 우울과 상관관계가 있는 것으로 조사되었다. 지연된 수면위상증후군이 의심되는 응답자는 일반 수면위상을 가진 응답자에 비해 주간졸림증 및 스트레스에서 유의미한 차이를 보였다. This study aims to reveal that college students’ regular sleep habits and the delayed sleep phase correlate with the quality of sleep, excessive daytime sleepiness, depression, and stress. SP22 23.0 was used in this study to analyze the data collected through an online survey from 122 students in the health departments of two universities in Gyeongsang-do. The analysis results demonstrate several correlations. Among the regular sleep habits, the average weekday wake-up time correlates with the average weekday sleep time, and the average bedtime correlates with the average weekday sleep time, the average weekday wake-up time, and gender. In addition, the average weekend wake-up time correlates with the average weekday sleep time, the average weekend sleep time, the average weekday wake-up time, and the average weekday bedtime. Furthermore, the average weekend bedtime correlates with the average weekday sleep time, the average weekday wake-up time, the average weekday bedtime, and the average weekend wake-up time. This study reveals that the suspected respondents of the delayed sleep phase syndrome showed significant differences in daytime sleepiness and stress compared to respondents with regular sleep phases. In addition, it was found that the quality of sleep and daytime sleepiness correlate with stress and depression, and stress correlates with depression.

WLAN 대역 신호 간섭 제거용 노치 필터를 내장한 45nm CMOS 공정 기반의 UWB LNA 회로 설계

이원준(Lee Won-Joon),박나린(Park Na-Lin),이예훈(Ye Hoon Lee) 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.11

에어튜브를 휨보강재로 활용한 현장타설말뚝 철근망 시공법 개발

이원준(Lee, Won Joon),정길제(Jung, Kilje),이성형(Lee, Sung Hyung) 대한토목학회 2023 대한토목학회 학술대회 Vol.2023 No.10

하이퍼 파라미터 최적화 기법을 적용한 이상 거래 탐지 시스템

이원준(Won-Joon Lee),서민혜(Min-Hye Seo),신나라(Na-Ra Shin) 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6

This paper proposes new Fraud Detection System with Hyper-parameter Optimization to develop for the limitations of existing FDS. We use Hyper-parmeter Optimization Algorithm that Naïve Evolution Algorithm(based Genetic Algorithm) and Tree-structured Parzen Estimator Algorithm(based Bayesian Optimization Algorithm). The main result of this study is TPE Algorithm shows better AUPRC values in less time than the Naïve Evolution Algorithm on two FDS Data Sets. The contribution of this paper is the improvement of FDS with HPO algorithm.

생리통 완화를 위한 저주파 치료기(TENS) 내장 스마트 개발 연구

이원준 ( Won Joon Lee ),엄소희 ( So Hee Um ) 복식문화학회 2009 服飾文化硏究 Vol.17 No.2

위상 파라미터 도출을 통한 H-MPSK의 BER 성능 분석

이원준(Won Joon Lee),박상규(Sang Kyu Park) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.4

계층적 M진 위상 편이 변조(hierarchical M-ary phase shift keying) 방식은 설정된 위상 파라미터에 따라 각 비트의 오류 성능이 변하기 때문에 각 시스템의 요구에 맞은 위상 파라미터 값을 구할 수 있는 방법을 필요로 한다. 따라서 본 논문에서는 계층적 M-PSK 변조 방식에 대한 BER의 근사적 접근을 통해 원하는 각 비트의 오류 성능에 따라 중요 위상 파라미터를 찾을 수 있는 방법을 제안하고, 이전에 제시된 계층적 M-PSK 변조 방식에 대한 정확한 오류 성능 분석 방법을 통하여 제안한 방법의 정당성을 검증한다. Bit error rate(BER) performance of each bit for hierarchical M-ary phase shift keying(H-MPSK) modulation scheme is changed according to the phase parameters. Thus, a method to find the phase parameters appropriate to the requests of the system is needed. In this paper, we propose a method to obtain the phase parameters from an approximate approach of BER for H-MPSK and verify a validity of the proposed method through the previously provided expression for analyzing an exact error probability of H-MPSK.