플렉서블 디스플레이용 저온공정을 갖는 대향 타겟식 스퍼터링 장치를 이용한 ZrO₂ 가스 차단막의 특성

김지환,조도현,손선영,김화민,김종재,Kim, Ji-Hwan,Cho, Do-Hyun,Sohn, Sun-Young,Kim, Hwa-Min,Kim, Jong-Jae 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.5

$ZrO_2$ film was deposited by facing target sputtering (FTS) system on polyethylene naphthalate (PEN) substrate as a gas barrier layer for flexible organic light emitting devices (FOLEDs), In order to control the heat of the FTS system caused by the ion bombardment in the cathode compared with the conventional sputtering system, the process characteristics of the FTS apparatus are investigated under various sputtering conditions such as the distance between two targets ($d_{TT}$), the distance between the target and the substrate ($d_{TS}$), and the deposition time. The $ZrO_2$ film by the FTS system can reduce the damage on the films because the ion bombardment with high-energy particles like gamma-electrons, Moreover, the $ZrO_2$ film with optimized condition ($d_{TT}$=140 mm) as a function of the distance from center to edge showed a very uniform thickness below 5 % for a deposition time of 3 hours, which can improve the interface property between the anode and the plastics substrate for flexible displays, It is concluded that the $ZrO_2$ film prepared by the FTS system can be applied as a gas barrier layer or an interlayer between the anode and the plastic substrate with good properties of an uniform thickness and a low deposition-temperature.

Escherichia coli에서 효소활성을 지닌 Human HtrA3 단백질 제조와 HtrA Serine Protease 1, 2와의 효소활성 비교

김지환,김구영,남민경,김상수,임향숙,Kim, Ji-Hwan,Kim, Goo-Young,Nam, Min-Kyung,Kim, Sang-Soo,Rhim, Hyang-Shuk 한국미생물학회 2009 미생물학회지 Vol.45 No.4

본 연구에서는 Human HtrA3 (HtrA3)의 효소활성을 분자수준에서 연구하기 위해 HtrA간의 상동성과 기존에 알려진 maturation site들을 비교 분석하여 예상 mature HtrA3인 M1-HtrA3와 M2-HtrA3를 발현하는 construct를 제작하였다. pGEX system을 통해 Top10 균주에서 발현, 정제한 M1-HtrA3 단백질은 $10{\mu}g$/L를 정제할 수 있었으며 발현량 대비 1%를 회수할 수 있었다. M2-HtrA3는 M1보다 5배 가량 많은 양을 정제할 수 있었으며 발현량 대비 회수율은 3배 정도 더 높았다. $\beta$-Casein을 이용한 in vitro cleavage test를 통해 M1, M2 form 모두 protease 활성을 갖는 것을 확인하였다. 또한, $\beta$-casein cleavage를 통해 HtrA serein protease들 간의 상대적인 활성을 비교한 결과, HtrA3와 HtrA2는 HtrA1보다 약 2배 더 높은 proteolytic cleavage 활성을 보였다. 본 연구에서 정립한 protease 활성을 지닌 HtrA3의 제작과 정제 조건은 HtrA3의 substrate를 탐색을 용이하게 할 수 있을 것이며, HtrA3 연관된 질환의 발병기전과 세포 신호전달을 이해하는 연구에 활용될 수 있을 것이다. To elucidate HtrA3's functional roles in the HtrA3 mediated cellular processes, it is necessary to investigate its biochemical characteristics. In the present study, we constructed the plasmids encoding putative mature HtrA3 proteins (M1-HtrA3 and M2-HtrA3) based on the putative maturation sites of highly homologous HtrA1 and mouse HtrA3. We used the pGEX bacterial expression system to develop a simple and rapid purification for the recombinant HtrA3 protein. Although yields of the mature HtrA3 proteins were slightly low as 10~50 ${\mu}g$/L, the amounts and purity of M1- and M2-HtrA3 were enough to investigate their proteolytic activities. The putative mature HtrA3 proteins have proteolytic activity which could cleave $\beta$-casein as an exogenous substrate. We compared the proteolytic activity between the HtrA family, HtrA1, HtrA2, and HtrA3. The cleavage activity of HtrA3 and HtrA2 were 2 folds higher than that of HtrA1, respectively. Our study provides a method for generating useful reagents to identify natural substrates of HtrA3 in the further studies.

Analysis of stress distribution of tooth restored with metal-ceramic crown covering abfraction lesion according to its finish line location under occlusal load

김지환,윤철욱,김태현,김한성,우대곤,이근우,심준성,Kim, Jee-Hwan,Yoon, Chol-Wook,Kim, Taehyeon,Kim, Han-Sung,Woo, Dae-Gon,Lee, Keun-Woo,Shim, June-Sung The Korean Academy of Prosthodonitics 2014 대한치과보철학회지 Vol.52 No.4

목적: 다양한 원인으로 발생된 Abfraction 병소가 있는 치아를 금속도재관으로 수복 할 경우, 변연의 위치에 따라 예후가 다양해질 수 있다. 수복물의 장기적 성공을 검증하기 위해서는 응력분포의 분석이 필요하지만 금속도재관이 abfraction 병소의 적응증인 경우 금속도재관이 응력 분포에 미치는 영향을 밝히는 연구는 아직 없다. 본 연구의 목적은 abfraction 병소가 있는 치아를 수복하는 금속도재관이 바람직한 응력 분포를 나타낼 수 있는 조건을 알아 보고자 함이다. 재료 및 방법: 치아, 주위 조직과 금속 도재관의 외형을 반영한 2차원 유한 요소모델을 제작하고 144 N의 편심 교합력 하에서의 응력분포를 유한요소 분석법으로 분석하였다. 금속 도재관의 변연 위치를 쐐기모양의 결손부의 하연에(Group 0), 그리고 결손부의 하연보다 1 mm 하방(Group 1)과 2mm 하방(Group2)에 위치시켰다. 결과: Group 0에서 von Mises stress는 금속 도재관의 변연과 결손부의 첨부에 집중 되었고 협측 변연의 응력은 설측 부위로 분포되었다. Group 1과 Group 2에서의 응력분포양상은 비슷하게 나타났다. 응력은 결손부의 첨부에 집중되지만 협측과 설측의 응력띠는 서로 분리된 양상으로 나타났다. 결론: 금속도재관의 변연을 Abfraction 병소의 하연에 설정할 경우, 금속도재관은 Abfraction 병소의 첨부에 응력을 집중시킨다. Purpose: When the full veneer crown was treated in the tooth with abfraction lesion due to various causes, the prognosis of it may be compromised according to the location of the finish line, but there is few study about the location of its buccal finish line. The purpose of this study was to investigate the effect of location of the finish line of the full veneer crown on stress distribution of the tooth with abfraction lesion. Materials and methods: The two dimensional finite element model was developed to express tooth, surrounding tissue and full veneer crown. The stress distribution under eccentric 144 N occlusal load was analyzed using finite element analysis. The location of finish line was set just at the lower border of the lesion (Group 0), 1 mm (Group 1) and 2 mm (Group 2) below the lower border of the lesion. Results: In the Group 0, von Mises stress was concentrated at the finish line and the apex of the lesion. Also, the stress at the bucal finish line propagated to the lingual side. In the Group 1 and Group 2, stress distribution was similar each other. Stress was concentrated at the apex of lesion, but the stress at the buccal finish line did not propagate to the lingual side. That implied decrease of the possibility of horizontal crown fracture. Conclusion: Full veneer crown alleviated the stress concentrated at the apex of the abfraction lesion, when the finish line of full veneer crown was set below the lower border of abfraction lesion.

특정 호흡수에서 행한 통제호흡이 심박변이도에 미치는 영향

김지환,김병수,박성식,이용재,금나래,배효상,Kim, Ji-Hwan,Kim, Byoung-Soo,Park, Seong-Sik,Lee, Yong-Jae,Keum, Na-Rae,Bae, Hyo-Sang 사상체질의학회 2016 사상체질의학회지 Vol.28 No.2

Objectives We observed what effects of Paced Breathing(PB) in specific respiration rate have on heart rate variability (HRV) according to Sasang Constitution.Methods HRV of 72 healthy participants in sitting position was recorded while they carried out usual breathing, 0.2Hz, 0.1Hz, and 0.05Hz PB each 5 minutes in consecutive order. Five minute of relaxation was permitted between each breathing. Finally, HRV indices were statictically analyzed of 32 participants (SOEUM: 11, SOYANG: 10, TAEEUM: 11) after data out of accord with respiration rate or outliers were excluded.Results and Conclusions According to respiration rates, there was no statistical significance of HRV among Sasang Constitution. Regardless of Sasang Constituion, 0.2Hz PB increased mean heart rate and decreased natural logarithmic low frequency(lnLF) oscillation of HRV without the change of natural logarithmic high frequency(lnHF), while 0.1Hz PB increased lnLF and standard deviation of N-N interval(SDNN), and slightly decreased lnHF without the change of mean heart rate. 0.05 Hz PB also showed the same effect as 0.1Hz PB, but was impracticable.

음성 자료에 대한 규칙 기반 Named Entity 인식

김지환,Kim Ji-Hwan 대한음성학회 2006 말소리 Vol.58 No.-

In this paper, a rule-based (transformation-based) NE recognition system is proposed. This system uses Brill's rule inference approach. The performance of the rule-based system and IdentiFinder, one of most successful stochastic systems, are compared. In the baseline case (no punctuation and no capitalisation), both systems show almost equal performance. They also have similar performance in the case of additional information such as punctuation, capitalisation and name lists. The performances of both systems degrade linearly with the number of speech recognition errors, and their rates of degradation are almost equal. These results show that automatic rule inference is a viable alternative to the HMM-based approach to NE recognition, but it retains the advantages of a rule-based approach.

알렌드로네이트의 투여기간이 발치와의 치유에 미치는 영향: 예비실험

김지환,홍종환,최현민,박영범,문홍석,Kim, Jee-Hwan,Hong, Jong-Hwan,Choi, Hyun-Min,Park, Young-Bum,Moon, Hong-Seok 대한치과보철학회 2013 대한치과보철학회지 Vol.51 No.3

연구 목적: 본 연구에서는 알렌드로네이트 투여기간의 차이가 백서의 상악 제 1대구치 발치와의 초기 창상치유에 미치는 영향을 알아보고자 하였다. 연구 재료 및 방법: 4주령 Sprague Dawley Rat (Body weight 130-140 g) 15마리를 이용하여 알렌드로네이트(Merial Inc., Parramatta, Australia) 투여군(실험군)과 투여하지 않은 대조군으로 나누고 실험군은 다시 투여기간에 따라 1주 투여군부터 2주 투여군, 4주 투여군, 6주 투여군까지 총 4개의 실험군으로 나눴다. 실험군에 정해진 시기(발치 5 주전, 발치 3주전, 발치 1주전, 발치 시)부터 발치 1주 후까지 알렌드로네이트를 1 mg/kg의 농도로 주 3회 피하주사 한 후 6주 투여군과 대조군에서 한 개체씩을 이용하여 미세배열(microarray)분석을 실시하였고, 다른 시편들을 이용하여 조직학적 분석을 시행하였다. 발치와 내에서의 신생골의 형성 비율과 발치와 주위 골에서 활성을 잃은 뼈에 대해 분석하였고, 파골세포 표지자인 TRAP 염색을 하여 분석하였다. 통계적인 분석으로 크루스컬-왈리스 검정(Kruskal Wallis test)을 실시하였다(${\alpha}=.05$). 결과:발치 후 1주 시점에서의 발치와 내에서의 신생골의 생성 비율은 대조군보다 ($16.77%{\pm}1.36%$) 4주 투여군($14.99%{\pm}6.26%$)에서 더 낮게 나오는 경향은 있었지만 유의 하지는 않았다. 투여기간이 증가할수록 활성을 잃은 골수강(empty lacuna)의 수는 증가하였고, TRAP positive cell 수는 감소하는 경향이 있으나 유의하지는 않았다. 결론: 본 예비실험을 통해서 알렌드로네이트의 투여기간이 증가할수록 신생골의 생성 비율이 감소되고 활성을 잃은 뼈들이 많아지며 파골세포의 수는 줄어드는 경향이 있음을 알 수 있었으나 통계적으로 유의차는 없었다. Purpose: The purpose of this study was to investigate the effect of different administration duration of alendronate on initial wound healing and new bone formation of extraction socket in rats. Materials and methods: Fifteen male Sprague-Dawley rats (body weight 130-140 g, 4 weeks old, male) were divided into control group (no alendronate administration) and experimental group (alendronate administration). Experimental group was subdivided into 1 week administrated group, 2 week administrated group, 4 week administrated group and 6 week administrated group according to duration of administration. For the experimental groups, during the designated time period (at the time of extraction, 1 week before extraction, 3 week before extraction and 5 week before extraction) till 1 week after extraction, rats were subcutaneously injected with Alendronate at the dose of 1.0 mg/Kg three times a week. Each specimen from 6 week experimental group and control group were used for microarray analysis, and other specimens were used for histological analysis. The rate of new bone formation within the extraction site and bone loss activity was analyzed using TRAP staining. Statistical analysis was performed using Kruskal Wallis test. (${\alpha}=.05$) Results: After one week from the time of extraction, the rate of new bone formation within extraction site for the control group ($16.77%{\pm}1.36%$) compared to the 4 week experimental group ($14.99%{\pm}6.26%$) was lower. However, no statistically significant difference was found. Increase in the number of inactive lacuna (empty lacuna) and decrease in the number of TRAP positive cell were identified with increased duration of administration. There was no significant difference. Conclusion: The results of this study showed as the duration of Alendronate administration increased the rate of new bone formation decreased with loss of bone activity and reduced number of osteoclast.

Carbon Black 의 비이온 계면활성제의 종류에 따른 흡착특성 변화에 관한 연구

김지환,이창우,홍영호,장윤호,홍인권,함영민 ( Ji Hwan Kim,Chang Woo Lee,Young Ho Hong,Yun Ho Jang,In Kwon Hong,Yeong Min Hahm ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.1

자동 대소문자 식별을 이용한 영어 음성인식 결과의 가독성 향상

김지환,Kim, Ji-Hwan 대한음성학회 2007 말소리 Vol.61 No.-

A modified speech recogniser have been proposed for automatic capitalisation generation to improve the readability of English speech recognition output. In this modified speech recogniser, every word in its vocabulary is duplicated: once in a de-caplitalised form and again in the capitalised forms. In addition its language model is re-trained on mixed case texts. In order to evaluate the performance of the proposed system, experiments of automatic capitalisation generation were performed for 3 hours of Broadcast News(BN) test data using the modified HTK BN transcription system. The proposed system produced an F-measure of 0.7317 for automatic capitalisation generation with an SER of 48.55, a precision of 0.7736 and a recall of 0.6942.

진공 웹코터로 제작된 대면적 ITO/PET의 특성 연구

김지환,박동희,김종빈,변동진,최원국,Kim, Ji-Hwan,Park, Dong-Hee,Kim, Jong-Bin,Byun, Dong-Jin,Choi, Won-Kook 한국재료학회 2007 한국재료학회지 Vol.17 No.10

Indium tin oxide, which is used as transparent conducting layer in flexible device, is deposited on PET film by a magnetron sputtering in 300 mm wide roll-to-roll process (vacuum web coating). Sheet resistance, specific resistance and transmittance is differed by sputtering parameters such as working pressures, oxygen partial pressure, and thickness of ITO layer. ITO layer is deposited about 90 nm at roll speed of 0.24 m/min and its sputtering power is 3 kW. From the XRD spectrum deposited ITO layer is verified as amorphous. Under working pressure varied from $3{\times}10^{-4}\;Torr$ to $2{\times}10^{-3}\;Torr$, sheet resistance is lowest at the working pressure of $1{\times}10^{-3}\;Torr$ and its value is from $110\;{\Omega}/{\square}$ to $260\;{\Omega}/{\square}$ at the thickness of 90 nm. Oxygen partial pressure also varies sheet resistance and is optimized at the regime from 0.2% ($1.8{\times}10^{-6}\;Torr$) to 0.6% ($6{\times}10^{-6}\;Torr$). In this oxygen partial pressure sheet resistance is lower than $150\;{\Omega}/{\square}$. As ITO layer thickness increases, sheet resistance decreases down to $21\;{\Omega}/{\square}$ and specific resistance is about $7.5{\times}10.4{\Omega}cm$ in 340 nm thickness ITO layer. Transmittance is measured at the wavelength of 550 nm and is about 90% for 180 nm thickness ITO/PET.

High performance organic planar heterojunction solar cells by controlling the molecular orientation

김지환,김효정,Tae Min Kim,Tae Gun Kim,Jeong-Hwan Lee,김정원,김장주 한국물리학회 2013 Current Applied Physics Vol.13 No.1

A highly efficient planar heterojunction OSC based on zinc phthalocyanine (ZnPc)/fullerene (C60) by controlling the orientation of the ZnPc by using copper iodide (CuI) as the interfacial layer is reported. The proportion of face-on ZnPc molecules was increased significantly on the CuI layer compared to the layer without the CuI layer, which was analyzed with wide-angle X-ray scattering (WAXS) and optical absorption. The power conversion efficiency (PCE) of the orientation controlled planar heterojunction OSC was remarkably enhanced to 3.2 0.1% compared with 1.2 0.1% of the conventional OSCs without the control of the molecular orientation. By inserting the 3-nm-thick CuI layer, JSC, VOC and FF have increased from 4.6 0.2 to 8.9 0.2 mA cm2, from 0.48 0.01 to 0.59 0.02 V, and from 0.56 0.01 to 0.61 0.02, respectively. VOC enhancement is discussed with the result of the ultraviolet photoemission spectra (UPS) measurements.