• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.537-539
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• 2006

We developed an 4.5" $192{\times}64$ active matrix organic light-emitting diode display on a glass using organic thin-film transistor (OTFT) switching-arrays with two transistors and a capacitor in each sub-pixel. The OTFTs has bottom contact structure with a unique gate insulator and pentacene for the active layer. The width and length of the switching OTFT is $800{\mu}m$ and $10{\mu}m$ respectively and the driving OTFT has $1200{\mu}m$ channel width with the same channel length. On/off ratio, mobility, on-current of switching OTFT and on-current of driving OTFT were $10^6,0.3{\sim}0.5\;cm^2/V{\cdot}sec$, order of 10 ${\mu}A$ and over 100 ${\mu}A$, respectively. AMOLEDs composed of the OTFT switching arrays and OLEDs made using vacuum deposition method were fabricated and driven to make moving images, successfully.

• 한국운동역학회지
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• 제21권5호
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• pp.521-528
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• 2011

The purpose of this study was to analyze the kinematic characteristics of the finalists in the women's 100 m event to provide important information to coaches and athletes. Three different biomechanics techniques were applied for analyzing sprinter motion: LAVEG, a panning technique, and 12 video cameras for 3 dimensional analysis of the 40 m - 70 m portion of the race. Carmelita Jeter(USA) performed the maximum speed of 10.54 m/s at the distance of 58.2 m. There was a tendency to show a better performance time with a high number of steps (p=.13) and shorter stride length (p=.14) among the 8 sprints. Furthermore, the stride frequency and the performance time were negatively correlated as a higher stride frequency had a positive impact on the performance time (p=.02). Based on 3 dimensional analysis, the 4 top ranked sprinters used the different strategies to maintain a high COM (Center of Mass) velocity during the mid portion of the race (40 m - 70 m). Carmelita Jeter(USA) showed more flexed knee and hip motion at heel contact (HC) to maintain a high COM velocity while S.A. Fraser-Pryce (JAM) showed more extended knee and hip motion at HC. On the other hands, Veronica Campbell-Brown (JAM) and Kelly-Ann Baptiste (TRI) showed a tendency to have high knee lifts during the swing phase to maintain the high COM velocity during the race. These biomechanical analyses of the women's 100 m final event in the 2011 WC, Daegu, will provide important scientific information to coaches and athletes for understanding the sprinting mechanism of today's top-class sprinters.

• Journal of Periodontal and Implant Science
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• 제42권1호
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• pp.13-19
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• 2012

Purpose: The aim of this study was to examine whether a previous peri-implantitis site can affect osseointegration, by comparing implant placement at a site where peri-implantitis was present and at a normal bone site. A second aim of this study was to identify the tissue and bone reaction after treating the contaminated implant surface to determine the optimal treatment for peri-implant diseases. Methods: A peri-implant mucositis model for dogs was prepared to determine the optimal treatment option for peri-implant mucositis or peri-implantitis. The implants were inserted partially to a length of 6 mm. The upper 4 mm part of the dental implants was exposed to the oral environment. Simple exposure for 2 weeks contaminated the implant surface. After 2 weeks, the implants were divided into three groups: untreated, swabbed with saline, and swabbed with $H_2O_2$. Three implants from each group were placed to the full length in the same spot. The other three implants were placed fully into newly prepared bone. After eight weeks of healing, the animals were sacrificed. Ground sections, representing the mid-buccal-lingual plane, were prepared for histological analysis. The analysis was evaluated clinically and histometrically. Results: The untreated implants and $H_2O_2$-swabbed implants showed gingival inflammation. Only the saline-swabbed implant group showed re-osseointegration and no gingival inflammation. There was no difference in regeneration height or bone-to-implant contact between in situ implant placement and implant placement in the new bone site. Conclusions: It can be concluded that cleaning with saline may be effective in implant decontamination. After implant surface decontamination, implant installation in a previous peri-implant diseased site may not interfere with osseointegration.

• 한국응용곤충학회지
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• 제3권
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• pp.1-5
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• 1964

한국 전역에 널리 발생하는 아까시나무의 모자이크병에 대해서, 그 병징을 관찰 기재하고 접목전염시험을 하였다. 본병은 전형적인 mosaic의 양상을 이루며, 접목에 의하여 용역하게 전염되는 것으로 미루어 일종의 virus병으로 생각된다. 접목전염시험에 있어서는 건묘에 병수를, 또는 병근에 건수를 접함으로써, 공히 용역하게 전염시킬 수 있었다. 건묘에 병수를 접한 것에서는, 접하고 일정기간 경과 후 (10-30일) 접수(병)를 박리한 것이, 박리않고 그대로 방치한 것에 비하여 훨씬 감염발병이 양호하였으며, 대목과 접수가 접착한 10-30일간에 있어서의 접착기간의 장단에 따르는 감염율의 증감은 인정할 수 없었다. 그리고 대목과 접수(병)의 유착이 안되었을 경우에도 전염이 되었다. 목병은 그 병징, 접목에 의한 전염, 그리고 즙액전염의 가능(미발표) 등으로 미루어 Atanasoff(1935), 그리고 Milinko등(1961)이 보고한 동남유럽에 분포하는 아까시나무 mosaic disease와 근연의 것이 아닌가 생각된다. 한편 김명오 등(1961)은 한국에 아까시나무 witches broom이 발생하는 것으로 기록했는데, 이는 본 모자이크병을 가리킴이 아닌가 생각된다.

• Structural Engineering and Mechanics
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• 제55권4호
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• pp.857-869
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• 2015

The aluminum 7075-T6 is known as an alloy widely used in aircraft structural applications, which does not exhibit strain rate sensitivity during dynamic compressive tests. Despite mechanical importance of the material, there is not enough attention to determine appropriate sample dimensions such as a sample diameter relative to the device bar diameter and sample length to diameter (L/D) ratio for dynamic tests and how these two parameters can change mechanical behaviors of the sample under dynamic loading condition. In this study, various samples which have different diameters of 31.8, 25.4, 15.9, and 9.5 mm and sample L/D ratios of 2.0, 1.5, 1.0, 0.5, and 0.25 were tested using Split Hopkinson Pressure Bar (SHPB), as this testing device is proper to characterize mechanical behaviors of solid materials at high strain rates. The mechanical behavior of this alloy was examined under ${\sim}200-5,500s^{-1}$ dynamic strain rate. Aluminum samples of 2.0, 1.5 and 1.0 of L/D ratios were well fitted into the stress-strain curve, Madison and Green's diagram, regardless of the sample diameters. Also, the 0.5 and 0.25 L/D ratio samples having the diameter of 31.8 and 25.4 mm followed the stress-strain curve. As results, larger samples (31.8 and 25.4 mm) in diameters followed the stress-strain curve regardless of the L/D ratios, whereas the 0.5 and 0.25 L/D ratios of small diameter sample (15.9 and 9.5 mm) did not follow the stress-strain diagram but significantly deviate from the diagram. Our results indicate that the L/D ratio is important determinant in stress-strain responses under the SHPB test when the sample diameter is small relative to the test bar diameter (31.8 mm), but when sample diameter is close to the bar diameter, L/D ratio does not significantly affect the stress-strain responses. This suggests that the areal mismatch (non-contact area of the testing bar) between the sample and the bar can misrepresent mechanical behaviors of the aluminum 7075-T6 at the dynamic loading condition.

• 한국재료학회지
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• 제13권3호
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• pp.185-190
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• 2003

Titanium dioxide films were prepared by RF sputtering method on glass for various oxygen partial pressures at power 270 W. The crystal structure, photocatalytic property and the hydrophilicity of $TiO_2$thin film the deposition conditions were investigated. Crystallized anatase phase was observed in $TiO_2$film deposited at the ratio of oxygen partial pressure 10% and 20% for 2 hrs. As the increase of deposition time, the grain size and void size of $TiO_2$film have increased and also $V_2$films have been good crystallinity. The ultraviolet-visible light absorption of $TiO_2$films was increased with increasing of deposition time and occured chiefly at the wavelength between 280 and 340 nm. The absorption band was shifted to a longer wave length as deposition time increased. Water contact angle on the X$TiO_2$film of anatase structure was decreased with increasing ultraviolet illumination time and became lower than $11^{\circ}$ from $83^{\circ}$. When hydrophilic $TiO_2$film changed by enough ultraviolet illumination was stored in the dark, the film surface gradually turned to hydrophobic state.

• 대한치과의사협회지
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• 제48권7호
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• pp.538-546
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• 2010

Dental surgical procedures are potentially stress-inducing to not only patients but clinicians especially in case of medically compromised patients. The body response to dental stress involves the cardiovascular, respiratory and the endocrine system. To minimize the stress to the medically compromised patients, the stress reduction protocols should be established. The protocols include (1) Recognize the patient's degree of medical risk (2) Medical consultation before dental therapy (3) Schedule the patient's appointment in the morning (4) Monitor and record preoperative, perioperative and postoperative vital signs (5) Intra-venous sedation during surgical procedures (6) Adequate pain control during therapy (7) Short length of appointment time (8) Contact the patients on the same day. Two cases of Bisphosphonate-related osteonecrosis of the jaws were analyzed. There were 2 women, and the mean age was 70 years (range, 64~74 years). both are medically compromised, with steroids. Both patients were taking an oral bisphosphonate for several years. BRONJ is defined as an area of exposed bone of more than 8 weeks - duration in a patient taking a bisphosphonate for bone disease. Bisphosphonates have been widely prescribed over the last decade for a range of bone diseases, mainly intravenously for bone cancers and orally for osteoporosis. Although it is still controversial as to precisely how the bisphosphonates work, generally it is accepted that they prevent osteoclast action, with consequent cessation of osteoblast activity, so that the bone turnover is markedly reduced or ceased. The aim of this study is to informed the clinicians how to prepare and recognize in case of the BRONJ with medically compromised patients.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.615-618
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• 2005

In this work, the effects of corner transistors in SOI MOSFETs were investigated. We fabricated SOI MOSFETs with various widths and a fixed length and characterized them. The SOI thickness was $4000{\AA}$ and the buried oxide(BOX) thickness was $4000{\AA}$. The isolation of active region was simply done by silicon etching and TEOS sidewall formation. Several undesirable characteristics have been reported for LOCOS isolation in fabrication on SOI wafers so far. Although we used an STI-like process instead of LOCOS, there were still a couple of abnormal phenomena such as kinks and double humps in drain current. Above all, we investigated the location of the parasitic transistors and found that they were at the corners of the SOI in width direction by high-resolution SEM inspection. It turned out that their characteristics are strongly dependent on the channel width. We made a contact pad through which we can control the body potential and figured out the dependency of operation on the body potential. The double humps became more prominent as the body bias went more negative until the full depletion of the channel where the threshold voltage shift did not occur any more. Through these works, we could get insights on the process that can reduce the effects of corner transistors in SOI MOSFETs, and several possible solutions are suggested at the end.

• 한국철도학회논문집
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• 제19권3호
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• pp.304-313
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• 2016

고속열차의 정확한 위치를 검지하기 위해서는 차상에 설치된 트랜스폰더 리더가 지상에 설치된 트랜스폰더 태그로부터 텔레그램을 오류없이 정확하게 수신하여야 한다. 고속철도 환경에서 텔레그램 수신 성능은 선로 변에 설치된 전기/신호 설비 및 열차에 설치된 전장품으로부터 발생하는 전자기 간섭의 영향을 받는다. 본 연구에서는 열차 위치검지시스템에 절대위치를 제공하기 위해 개발된 철도교통용 고속 트랜스폰더시스템 시작품의 철도환경 적합성을 검증하기 위하여, 호남고속선에 트랜스폰더 태그를 설치하고 HEMU-430X가 268km/h~334km/h로 운행할 때 트랜스 폰더 리더가 각 태그로부터 텔레그램을 오류없이 몇 회 수신하는지 측정하는 방식으로 실차 테스트를 수행하였다. 이를 바탕으로 트랜스폰더 리더와 태그 사이에 형성된 컨택 존의 길이를 추정하고, 400km/h의 고속주행환경에서 태그로부터 오류없이 수신가능한 텔레그램 개수를 예측하였다.

• Archives of Plastic Surgery
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• 제45권2호
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• pp.135-139
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• 2018

Background Static reconstruction surgery that tightens the tension of the inferior tarsus, thereby raising the lax lower eyelid, is a common treatment for paralytic ectropion of the lower eyelid. We present one such operative procedure, in which an orbicularis oculi muscle flap was used. Methods The surgical technique involves partial resection of the tarsus and the skin, as well as a superior-based orbicularis oculi muscle flap that is sutured to the firm tissue present on the Whitnall tubercle. The muscle flap is approximately 7 mm in width and 15 mm in length, with a superior pedicle that is attached to the tarsus at the medial point of the resected tarsus. The procedure results in contact between the ocular surface and the lower eyelid. Results The procedure was performed in 11 patients with lower eyelid ectropion due to facial paralysis. Ten cases showed a favorable outcome following surgery, with stable results seen over an average follow-up period of 4.5 years. In one case, recurrence of ectropion was observed 2 months after surgery due to an insufficient correction, and the patient required repeat surgery. Conclusions The orbicularis oculi muscle flap was an effective means of suspension and was able to maintain long-term traction tension. This procedure can therefore be considered a favorable treatment option for lower eyelid ectropion due to facial paralysis.