전자빔 조사 및 Ag 완충층에 의한 ZnO/Ag 박막의 구조적·광학적·전기적 특성 개선 효과

최진영,엄태영,박윤제,최수현,김대현,조윤주,김대일,Choi, Jin-Young,Eom, Tae-Young,Park, Yun-Je,Choi, Su-Hyun,Kim, Dae-Hyun,Cho, Yun-Ju,Kim, Daeil 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.4

In this work, in order to effectively improve the electrical conductivity and visible light transmittance of ZnO thin films, ZnO single layer and ZnO/Ag bi-layer films were deposited on glass substrates by radio frequency and direct current magnetron sputtering, and then, the effects of an Ag buffer layer and electron beam irradiation on the electrical and optical properties of the films were investigated. The observed results indicate that ZnO 100 nm / Ag 7 nm films show higher opto-electrical performance than the ZnO single layer film. In addition, electron beam irradiation also effectively enhanced the visible transmittance and electrical conductivity of the ZnO/Ag bi-layer films.

기생저항 및 트랜지스터 비대칭이 고저항 SRAM 셀의 읽기동작에 미치는 영향

최진영,최원상,Choi, Jin-Young,Choi, Won-Sang 한국전기전자학회 1997 전기전자학회논문지 Vol.1 No.1

회로 시뮬레이터를 이용하는 DC 셀 노드전압 분석방법을 적용하여, 고저항 SRAM 셀 구조에서 기생저항들과 트랜지스터 비대칭에 의해 야기되는 정적 읽기동작에서의 동작마진을 조사하였다. 이상적인 셀에 기생저항을 선택적으로 추가함으로써 각 기생저항들이 동작 마진에 끼치는 영향을 조사한 뒤, 기생저항이 좌우대칭 쌍으로 존재하는 경우에 대해 조사하고, 또한 셀 트랜지스터의 채널폭을 선택적으로 변화시켜 트랜지스터의 비대칭을 야기시킴으로써 트랜지스터 비대칭에 의한 동작 마진의 저하를 분석하였다. 분석 방법은 시뮬레이션된 셀 노드전압 특성에서 두 셀 노드전압이 하나의 값으로 수렴되는 전원전압의 값과 $V_{DD}=5V$에서 셀 노드전압의 차를 비교함으로써 상대적인 동작 마진을 비교하는 방법을 사용하였다. 회로 시뮬레이션에 의존한 본 분석으로부터 셀의 정적 읽기동작에 가장 심각한 영향을 끼치는 기생저항 성분과 트랜지스터의 비대칭 형태를 규명함으로써 새로운 셀 구조 설계시 참고할 수 있는 기준을 제시하였다. By utilizing the technique to monitor the DC cell node voltages through circuit simulation, degradation of the static read operating margin In high load-resistor SRAM cell was examined, which is caused by parasitic resistances and transistor asymmetries in this cell structure. By selectively adding the parasitic resistances to an ideal cell, the influence of each parasitic resistance on the operating margin was examined, and then the cases with parasitic resistances in pairs were also examined. By selectively changing the channel width of cell transistors to generate cell asymmetry, the influence of cell asymmetry on the operating margin was also examined. Analyses on the operating margins were performed by comparing the supply voltage values at which two cell node voltages merge to a single value and the differences of cell node voltages at VDD=5V in the simulated node voltage characteristics. By determining the parasitic resistances and the transistor asymmetries which give the most serious effect on the static read-operation of SRAM cell from this analysis based on circuit simulated, a criteria was provided, which can be referred in the design of new SRAM cell structures.

Simulated Annealing for Two-Agent Scheduling Problem with Exponential Job-Dependent Position-Based Learning Effects

최진영,Choi, Jin Young The Korea Society for Simulation 2015 한국시뮬레이션학회 논문지 Vol.24 No.4

In this paper, we consider a two-agent single-machine scheduling problem with exponential job-dependent position-based learning effects. The objective is to minimize the total weighted completion time of one agent with the restriction that the makespan of the other agent cannot exceed an upper bound. First, we propose a branch-and-bound algorithm by developing some dominance /feasibility properties and a lower bound to find an optimal solution. Second, we design an efficient simulated annealing (SA) algorithm to search a near optimal solution by considering six different SAs to generate initial solutions. We show the performance superiority of the suggested SA using a numerical experiment. Specifically, we verify that there is no significant difference in the performance of %errors between different considered SAs using the paired t-test. Furthermore, we testify that random generation method is better than the others for agent A, whereas the initial solution method for agent B did not affect the performance of %errors. 본 논문은 작업별 위치기반 지수학습 효과를 갖는 2-에이전트 단일기계 스케줄링 문제를 고려한다. 에이전트 A는 가중 완료 시간의 합을 최소화하며, 에이전트 B는 총소요시간에 대한 상한 값을 만족하는 조건을 갖는다. 본 연구에서는 먼저 우수해/가능해에 대한 특성을 개발하고, 이를 이용하여 최적 해를 찾기 위한 분지한계 알고리즘을 설계한다. 또한 근사 최적 해를 구하기 위해 6가지 다른 초기해 생성 방법을 이용한 시뮬레이티드 어닐링 알고리즘을 제안한다. 수치 실험을 통해 제안된 알고리즘의 우수한 성능을 검증한다. 실험 결과, 다른 초기해 생성 방법들 간에는 %errors 차이가 유의하게 발생하지 않았으며, 에이전트 A의 작업 순서를 무작위로 생성할 때 성능이 좋아짐을 발견하였다. 반면에, 에이전트 B의 초기해 생성 방법은 성능에 영향을 미치지 않았다.

연구개(軟口蓋) 인두간(咽頭間) 폐쇄부전(閉鎖不全)(Velopharyngeal Incompetency) 환자(患者)에 있어서 발음(發音) 장애(障碍)에 관한 연구(硏究)

최진영,민병일,Choi, Jin-Young,Min, Byoung-il 대한악안면성형재건외과학회 1992 Maxillofacial Plastic Reconstructive Surgery Vol.14 No.1

The purpose of this study was to evaluate hypernasality, nasal air emission, glottal stop, articulation disorder in patients with velopharyngeal incompetency(V.P.I.) and to analyze speech improvement after pharyngoplasty. In this study 61 patients with velopharyngeal incompetency were tested, and in patents with pharyngoplasty speech problems before pharyngoplasty were compared with those after pharyngoplasty. The results obtained are as follows : 1. There are few speech problems in pronouncing the vowel sounds. 2. There are many speech problems in pronouncing the pressure sounds and few speech problems in non-pressure sounds. 3. Speech problems in patients with cleft palate are influenced not by anatomical defect but by severity of velopharyngeal incompetence after palatorrhaphy. 4. Operation methods which decrease the velopharygeal incompetence must be considered for reducing the speech problems. 5. Among the 61 cases with V.P.I. 19 cases(31%) showed nasal air emission and 24 cases(39%) showed glottal stop. 6. Pharyngoplasty is of benefit to primary precipitating components such as hypernasality, nasal air emission but of no benefit to secondary compensating component such as glottal stop. 7. There as no significant difference in speech improvement between pre-and post-pharyngoplasty(p<0.05).

RF IC용 싸이리스터형 정전기 보호소자 설계에 관한 연구

최진영,조규상,Choi, Jin-Young,Cho, Kyu-Sang 한국전기전자학회 2003 전기전자학회논문지 Vol.7 No.2

Based on simulation results and accompanying analysis, we suggest a thyristor-type ESD protection device structure suitable for implementation in standard CMOS processes to reduce the parasitic capacitances added to the input nodes, which is very important in CMOS RF ICs. We compare DC breakdown characteristics of the suggested device to those of a conventional NMOS protection device to show the benefits of using the suggested device for ESD protection. The characteristic improvements are demonstrated and the corresponding mechanisms are explained based on simulations. Structure dependencies are also examined to define the optimal structure. AC simulation results are introduced to estimate the magnitude of reduction in the added parasitic capacitance when using the suggested device for ESD protection. The analysis shows a possibility of reducing the added parasitic capacitance down to about 1/40 of that resulting with a conventional NMOS protection transistor, while maintaining robustness against ESD. CMOS RF IC에서 중요한 문제가 되는 입력 노드에의 기생 커패시턴스 추가 문제를 줄이기 위해, 2차원 소자 시뮬레이션 결과 및 그에 따른 분석을 기반으로, 표준 CMOS 공정에서 쉽게 제작 가능한 pnpn 싸이리스터 구조의 ESD 보호용 소자를 제안한다. 제안된 소자의 DC 항복특성을 일반적으로 사용되고 있는 보호용 NMOS 트랜지스터 경우와 비교 분석하여 제안된 소자를 사용하였을 경우의 이점을 입증한다. 시뮬레이션을 통해 제안된 소자에 의한 특성 향상을 보이고 이와 관련된 미케니즘들에 대해 설명한다. 또한 제안된 소자의 최적 구조를 정의하기 위해 소자구조에 따른 특성변화를 조사한다. ESD 보호용으로 제안된 소자를 사용할 경우 추가되는 기생 커패시턴스의 감소 정도를 보이기 위해 AC 시뮬레이션 결과도 소개한다. 본 논문의 분석 결과는, CMOS RF IC에서 ESD 보호용으로 제안된 소자를 사용할 경우 NMOS 트랜지스터를 사용할 경우와 대비, 동일한 ESD 강도를 유지하면서 입력노드에 추가되는 커패시턴스의 양을 1/40 정도로 줄일 수 있는 가능성을 보여준다.

오미자탕(五味子湯)이 산화적 손상으로 유발된 세포고사에 미치는 영향

최진영,신선호,이윤재,Choi, Jin-Young,Shin, Sun-Ho,Lee, Yun-Jae 대한한방내과학회 2005 大韓韓方內科學會誌 Vol.26 No.2

The water extract of Omijatang(OMJT) has been traditionally used for treatment of abscess and heart palpitation in oriental medicine, However, little is known about the mechanism by which the water extract of OMJT rescues cells from these damages. This study was designed to investigate the protective mechanisms of OMJT in H9c2 cardiomyoblasts on oxidative stress-induced cytotoxicity including $H_2O_2,\;ZnCl_2$, hypoxia, and reoxygenation. Oxidative stress markedly decreased the viability of H9c2 cells. This was characterized with apparent apoptotic features such as chromatin condensation as well as fragmentation of genomic DNA and nuclei. However, OMJT significantly reduced $H_2O_2$-induced cell death and apoptotic characteristics as well as $ZnCl_2$, hypoxialreoxygenation. Taken together, this study suggests that the water extract of OMJT has the protective effects against oxidative injuries.

신경회로망을 이용한 다중 전극 와우각 이식 시스템용 음성처리 알고리즘

최진영,조진호,이건일,Choi, Jin-Young,Cho, Jin-Ho,Lee, Kuhn-Il 대한의용생체공학회 1990 의공학회지 Vol.11 No.1

A New speech processing algorithm using neural networks is proposed. We transform input data into frequency domain and process them by neural networks of 22 output neurons which have Bark scale on the ground that the Bark scale is similiar with that of the characteristics of human cochlea. An utilized neural network is multilayer perceptron, and the characteristics of cochlea have it trained by error back propagation learning algorithm. The trained neural networks suffices functions of human cochlea including the effects of automatic gain control, compression and equalization. Simulation results show that the proposed speech processing algorithm has good performance in automatic gain control, compression and equalization.

정전기 보호용 소자의 AC 모델링에 관한 연구

최진영,Choi, Jin-Young 한국전기전자학회 2004 전기전자학회논문지 Vol.8 No.1

2차원 소자 시뮬레이터를 이용한 AC 해석 결과를 토대로 ESD 보호용 소자의 AC 등가회로 모델링을 시도한다. NMOS 보호용 트랜지스터의 AC 등가회로는 다소 복잡한 형태로 모델링되며, 이를 간단히 RC 직렬회로로 모델링할 경우 주파수 영역에 따라 오차가 크게 발생할 수 있음을 설명한다. 또한 싸이리스터형 pnpn 보호용 소자의 등가회로는 간단히 RC 직렬회로로 모델링될 수 있음을 보인다. 추출한 등가회로를 이용한 회로 시뮬레이션에 근거하여, 주요 RF 회로의 하나인 LNA에 ESD 보호용 소자를 장착할 경우 보호용 소자의 기생성분이 LNA의 특성에 미치는 영향에 대해 조사해 본다. NMOS 보호용 트랜지스터를 단순히 커패시터 하나만으로 모델링할 경우 회로특성의 예측에 큰 오류가 발생할 수 있음을 설명한다. 또한 제시한 pnpn 보호용 소자를 사용할 경우 보호용 소자의 장착에 의한 LNA 회로의 특성 열화가 크게 감소될 수 있음을 확인한다. From the AC analysis results utilizing a two dimensional device simulator, the ac equivalent-circuit modeling of the ESD protection devices is executed. It is explained that the ac equivalent circuit of the NMOS protection transistor is modeled by a rather complicated form and that, depending on the frequency range, the error can be large if it is modeled by a simple RC serial circuit. It is also shown that the ac equivalent circuit of the thyristor-type pnpn protection device can be modeled by a simple RC serial circuit. Based on the circuit simulations utilizing the extracted equivalent circuits, the effects of the parasitics in the protection device on the characteristics of LNA are examined when the LNA, which is one of the important RF circuits, is equipped with the protection device. It is explained that a large error can result in estimating the circuit characteristics if the NMOS protection transistor is modeled by a simple capacitor. It is also confirmed that the degradation of the LNA characteristics by incorporating the ESD protection device can be reduced a lot by adopting the suggested pnpn device.

라식수술 후 재발된 근시에 있어 보강수술 방법에 따른 교정 효과의 비교

최진영,김현창,서경률,김응권,이형근,Jin Young Choi,Hyun Chang Kim,Kyoung Yul Seo,Eung Kweon Kim,Hyung Keun Lee 대한안과학회 2006 대한안과학회지 Vol.47 No.3

Purpose: To evaluate refraction and visual outcome between the enhancement methods on regressed or undercorrected myopia after primary laser in situ keratomileusis (LASIK). Methods: This prospective comparative study comprised 114 eyes of 114 patients who had enhancement between March 2003 and March 2004. A single surgeon performed all surgeries. Patients were subdivided according to enhancement methods lifting flap group (Group Ⅰ), LASEK enhancement group (Group Ⅱ) and tPRK group (Group Ⅲ). Flap was lifted in 55 eyes and LASEK enhancement was performed in 23 eyes. tPRK was done in 36 eyes. Uncorrected visual acuity (UCVA), best-corrected visual acuity, refractive error was examined prior to, and 1 week and 1, 3, 6 months after enhancement. Results: The mean time between initial LASIK and enhancement were 6.67±2.49 months in Group Ⅰ, 7.86±5.23 months in Group Ⅱ and 6.08±2.38 months in Group Ⅲ. At POD 6 months, the mean postoperative UCVA were 0.96±0.14 (0.026±0.079 logMAR), 0.97±0.15 (0.016±0.078 logMAR) and 0.89±0.21 (0.079±0.196 logMAR) snellen equivalent respectively and this did not differ significantly (p=0.166). The mean spherical equivalents were -0.60±0.69D (diopter), -0.91±0.75D and -0.88±0.60D respectively at POD 6 months and this also did not differ significantly (p=0.172). Conclusions: All three enhancement methods were useful procedure for correcting residual refractive errors after the primary LASIK. They provided good UCVA, predictable results and few complications.

약용식물(오크라, 엉컹퀴, 엄나무, 줄풀) 유래 페놀성 물질의 항산화 활성

최진영,조민경,구영미,김현경,신진원,김동영,김혜진,이은호,김나현,조영제,Choi, Jin-Young,Jo, Min-Kyeong,Goo, Young-Mi,Kim, Hyun-Kyung,Shin, Jin-Won,Kim, Dong-Yeong,Kim, Hye-Jin,Lee, Eun-Ho,Kim, Na-Hyun,Cho, Young-Je 경북대학교 농업과학기술연구소 2015 慶北大農學誌 Vol.33 No.2

안전한 천연물을 이용한 천연항산화제 개발 연구의 일환으로, 오크라, 엉컹퀴, 엄나무 및 줄풀 등 4종의 천연 약용식물 추출물의 항산화 활성을 측정해보았다. 추출물의 총 phenolic compounds 함량은 오크라와 엉컹퀴는 50% ethanol, 엄나무는 40% ethanol, 줄풀은 60% ethanol에서 최대용출을 나타내었으며, water 추출물에서 2.72~34.15 mg/g, ethanol 추출물에서 2.83~34.23 mg/g의 용출율을 나타내었다. 4종류 약용식물 water과 ethanol 추출물의 DPPH radical 소거능은 $50{\mu}g/mL$의 저농도에서 모두 74% 이상의 높은 소거활성을 나타내었다. ABTS radical cation decolorization을 측정한 결과, 4종의 약용식물 water 추출물과 ethanol 추출물 $100{\mu}g/mL$의 농도에서 모두 88% 이상의 높은 저해율을 나타내었다. 지용성 물질에 대한 항산화 효과를 측정하기 위해 antioxidant protection factor(PF)를 측정한 결과, 엉컹퀴 water과 ethanol 추출물 $50{\ddot{I}}g/mL$의 저 농도에서 각각 1.73과 1.76 PF로 다른 약용식물 보다 높은 항산화효과를 나타내었다. TBARs 생성 억제율을 측정한 결과 오크라를 제외한 3종의 약용식물 추출물 $50{\mu}g/mL$ phenolic 농도에서 80% 이상의 생성억제 효과를 나타내었다. 이러한 결과에 따라 다양한 약용식물 추출물이 항산화 및 기능성 식품 소재로 활용이 가능하다고 판단되었다. In this study, the antioxidant activity of water and ethanol extracts from Hibiscus esculentus, Cirsium japonicum, Zizania latifolia and Kalopanax pictus for functional food source were examined. The optimal conditions for phenolic compounds extraction from medicinal plants were at 50% ethanol with Hibiscus esculentus and Cirsium japonicum var. ussuriense, at 40% ethanol with Kalopanax pictus and at 60% ethanol with Zizania latifolia. The total phenolic contents from the extracts of medical plants were determined to be 2.72~34.15 mg/g in the water extracts and 2.83~34.23 mg/g in the ethanol extracts. The electron-donating abilities (EDA) of the water and ethanol extracts were both above 74% at the low concentration of $50{\mu}g/mL$. The ABTS radical-cation decolorization was above 88% at $100{\mu}g/mL$ concentration in all the extracts of various medicinal plants. The antioxidant protection factor (PF) in the water and ethanol extracts of the Cirsium japonicum var. ussuriense extracts was $1.73{\pm}0.02PF$ and $1.76{\pm}0.01PF$ at $50{\mu}g/mL$ concentration respectively, and was higher than those of the other medicinal-plant extracts. The TBARs inhibition rates of all the medicinal-plant extracts, were above 80% at the $50{\mu}g/mL$ concentration except Hibiscus esculentus. These results confirmed that the various oriental medicinal plants (Hibiscus esculentus, Cirsium japonicum var. ussuriense, Kalopanax pictus and Zizania latifolia) that were included in this study are useful anti-oxidant and functional-food resources.