• 치과방사선
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• 제24권2호
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• pp.337-345
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• 1994

Arthrography of the temporomandibular joint is a useful method of demonstrating the soft tissue abnormalities related to disc dysfunction. In this study, 19 asymptomatic joints, 31 joints with anterior disc displacement with reduction, 31 joints with anterior disc displacement without reduction which were classified by arthrotomography under fluoroscopy were evaluated to determine the linear measurement of anterior recess of inferior joint space and the relationship between the condylar anterior translation and the severity of the internal derangements. Their fluoroscopic images were also evaluated to describe the characteristics of condylar paths in internal derangements of the temporomandibular joints. The results were as follows; 1. The mean lengths of the anterior recess in asymptomaic group. reduction group. and non-reduction group were 8.7±1.6㎜. 11.2±1.7㎜, 12.8±1.7㎜ respectively. The length of the anterior recess was increased according to the severity of the internal derangements(P<0.05). 2. Linear measurements of anterior movement of condyle on maximum mouth opening were 13.1 ±4.2㎜, 15.9±4.1㎜, 5.0±3.7㎜ in asymptomatic group. reduction group, and non-reduction group respectively. Compared with asymptomatic group, reduction group showed hypermobolity of the condyle and non-reduction group showed hypomobility. 3. Condyles moved beyond the crest of articular eminence in 80% of reduction group and did not reach it in 70% of non-reduction group. 4. The condyle moved mainly superiorly in reduction group(66%) and horizontally in asymptomatic group(47%). There were no cases to move superiorly in non-reduction group.

• Journal of Korean Neurosurgical Society
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• 제44권3호
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• pp.124-130
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• 2008

Objective : Our purpose of this study is to compare insertion angles and screw lengths from Roy-Camille, Magerl, and our designed method for cervical lateral mass screw fixation in the Korean population by quantitative measurement of reformatted two dimensional (2D) computed tomography (CT) images. Methods : We selected thirty Korean patients who were evaluated with thin section CT scans and reconstruction program to obtain reformatted 2D-CT images of the transversal plane passing the cranio-caudal angle using three different techniques. We measured the minimum angle to avoid vertebral artery (VA) injury, the ideal angle and depth for bicortical screwing of cervical lateral mass. Morphometric measurements of the lateral masses from C3-C7 were also taken. Results : In all three techniques, the mean safety angles from the VA were less than 8 degrees and the necessary depth of the screw was about 14 mm for safety to the VA and for the bicortical purchase. In our designed technique, the mean $\beta$ angles of each level from C3 to C7 were 29.0. 29.8. 29.5. 26.3. and 23.9 degrees, respectively. Conclusion : Results of this study and data from the literature indicate that differences may exist between the Korean and Western people in the length and angle for ideal lateral mass screw fixation. In addition, our technique needs further cadaveric and clinical study for safety and efficacy for being performed as alternative method for cervical lateral mass fixation.

• 한국진공학회지
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• 제19권1호
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• pp.72-80
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• 2010

KSTAR ICRF 시스템에서 안테나 전류띠 간 커플링에 의한 전류띠의 전압, 전류 분포 변화와 전류띠 간 전력 전달에 의한 공명현상 그리고 전송선상의 이상 전압 분포 등을 예측하거나 분석하는 것은 그것의 안정적이고 신뢰성 있는 운전을 위해 매우 중요하다. 본 연구에서는 이러한 전류띠 간 커플링에 의한 현상들을 이해하기 위해 ICRF 안테나에서 측정한 S-parameter를 커플링이 고려된 8포트 전송선회로 모델에 적용하여 전류띠의 전송선 회로 모델을 완성하였다. 완성된 전송선 회로모델의 자체유도계수, 상호유도계수, 전기용량성 등은 전류띠의 유한한 길이로 인하여 2D 모델의 값보다 작은 것으로 나타났다. 커플링이 고려된 전류띠의 전송선 회로모델은 공명루프와 결합되어 있는 KSTAR ICRF 시스템의 운전에 활용될 것이다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.289.1-289.1
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• 2014

In this study, we made a organic thin film device in MIS(Metal-Insulator-Semiconductor) structure by using PVP (Poly vinyl phenol) as a insulating layer, and CdSe/ZnS nano particles which have a core/shell structure inside. We dissolved PVP and PMF in PGMEA, organic solvent, then formed a thin film through a spin coating. After that, it was cross-linked by annealing for 1 hour in a vacuum oven at $185^{\circ}C$. We operated FTIR measurement to check this, and discovered the amount of absorption reduced in the wave-length region near 3400 cm-1, so could observe decrease of -OH. Boonton7200 was used to measure a C-V relationship to confirm a properties of the nano particles, and as a result, the width of the memory window increased when device including nano particles. Additionally, we used HP4145B in order to make sure the electrical characteristics of the organic thin film device and analyzed a conduction mechanism of the device by measuring I-V relationship. When the voltage was low, FNT occurred chiefly, but as the voltage increased, Schottky Emission occurred mainly. We synthesized CdSe/ZnS and to confirm this, took a picture of Si substrate including nano particles with SEM. Spherical quantum dots were properly made. Due to this study, we realized there is high possibility of application of next generation memory device using organic thin film device and nano particles, and we expect more researches about this issue would be done.

• 한국재료학회지
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• 제30권10호
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• pp.558-565
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• 2020

AZO thin films are grown on a p-Si(111) substrate by RF magnetron sputtering. The characteristics of various thicknesses and heat treatment conditions are investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Hall effect and room-temperature photoluminescence (PL) measurements. The substrate temperature and the RF power during growth are kept constant at 400 ℃ and 200 W, respectively. AZO films are grown with a preferred orientation along the c-axis. As the thickness and the heat treatment temperature increases, the length of the c-axis decreases as Al³⁺ ions of relatively small ion radius are substituted for Zn²⁺ ions. At room temperature, the PL spectrum is separated into an NBE emission peak around 3.2 eV and a violet regions peak around 2.95 eV with increasing thickness, and the PL emission peak of 300 nm is red-shifted with increasing annealing temperature. In the XPS measurement, the peak intensity of Al_2p and O_ll increases with increasing annealing temperature. The AZO thin film of 100 nm thickness shows values of 6.5 × 10¹⁹ cm^-3 of carrier concentration, 8.4 cm^-2/V·s of mobility and 1.2 × 10^-2 Ω·cm electrical resistivity. As the thickness of the thin film increases, the carrier concentration and the mobility increase, resulting in the decrease of resistivity. With the carrier concentration, mobility decreases when the heat treatment temperature increases more than 500 ℃.

• 폴리머
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• 제26권2호
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• pp.200-208
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• 2002

난연성분인 트리클로로벤조산(TBA)의 함량을 10, 20, 30 wt%로 변화시키면서 아디프산, 1,4-부탄디올 및 트리메틸올프로판과 축중합을 하여 트리클로로 락톤 변성폴리에스테르(TAPTs)를 합성한 후에, TAPT류와 이소시아네이트인 Desmodur IL을 블렌드하여 2성분계 폴리우레탄 난연 도료를 제조하였다. 제조된 난연도료의 도막물성을 측정한 결과, 결코 비난연도료보다 물성이 떨어지지 않음을 알았다. 또한 난연도료의 3종류 난연성 시험결과, 수직법에서 TBA 함량 20 wt% 이상에서 불꽃에 타지 않았고, LOI 연소성 시험에서 TBA 함량 20, 30 wt%시 25%와 27%의 LOI값을 나타내었으며, $45^{\circ}$ Meckel burner법에서는 탄화길이가 3.6-5.2 cm로서 난연 1급에 해당되었으므로 이를 미루어 난연효과가 좋은 난연도료임을 알 수 있었다.

• 한국한의학연구원논문집
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• 제13권3호
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• pp.111-117
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• 2007

The study aims to measure and analyze the thickness and depth of blood vessel on the pulse diagnosis locations and the blood velocity through the use of ultrasonic waves (LOGIQ5PRO, GE Medical, U.S.) in order to understand the structural difference of pulse diagnosis locations. The subjects included 44 healthy men and women(22.28${\pm}$2.62 age) considered normal in terms of Body Mass Index(BMI). The thickness and depth of the blood vessel and the blood velocity were measured three times on CHON, KWAN and CHUCK to obtain the average value. Results showed there is a statistically significant difference among the variables measured on CHON, KWAN and CHUCK. A difference according to gender was also observed. This explains why an oriental medical doctor can tell the difference in pulses depending on the location of CHON, KWAN and CHUCK. In addition, the difference in pressure between CHON and KWAN was higher than that in pressure between KWAN and CHUCK. The findings explain why oriental medical doctors take pulses by dividing CHON, KWAN and CHUCK in the short length of the three fingers. It can be used to develop a pulse diagnosis device enabling accurate measurement according to the characteristics of blood vessel structure based on where the pulse is taken. Furthermore, the results can be used as basic data for the development of a pulse diagnosis simulator.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5923-5929
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• 2013

최근 국내에서도 구조물의 안정성을 향상시키고 수평토압의 크기를 줄여주는 선반식 옹벽에 대한 관심이 높아지고 있다. 이에 따라 모형시험 등 연구도 수행되기 시작했는데 기존 모형시험은 시험조건도 다양하지 않으며, 시험방법 등에서 개선해야 할 점이 있다. 이 연구에서는 개선된 모형시험 방법으로 여러 가지 다양한 조건에 대하여 모형시험을 수행하여 선반식 옹벽의 수평토압 감소효과를 확인하고자 하였다. 모형지반으로는 옹벽모형지반으로 일반적으로 많이 사용되는 주문진 모래를 이용하였으며, 1.2m의 모형옹벽을 15개 층으로 나누어 층마다 2개씩 총 30개의 로드셀을 사용하여 옹벽 높이별 수평토압을 측정하였다. 연구결과 선반식 옹벽은 캔틸레버식 옹벽에 비해 수평토압이 작게 발생하였으며, 선반 길이, 선반위치 등에 따라 수평토압의 크기가 영향을 받는 것으로 나타났다.

• Composites Research
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• 제16권3호
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• pp.9-17
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• 2003

타이어 벨트층내의 코드간 균열연결 및 층간균열진전을 모사하기 위해 자유단을 갖는 2층 고무/코드 적층시험편에 대한 4~11mm 변위제어 실험을 수행하였다. 자유단의 코드간 균열연결시의 폭방향 균열진전량은 45$^{\circ}$ 경사진 코드들간 길이의 절반에 도달할 때의 측정값으로 하였으며, 이는 탐침법에 의해 측정되었다 또한, 자유단에서 코드들간 균열연결을 모사하기위해 2차원의 이상화된 모델링 기법을 고안하였다. 이론수명은 테어링에너지(균열파단면의 단위면적당 방출에너지)를 이용하여 코드간 균열연결수명(임계값)과 이후 최종파손까지의 수명으로 구분하였으며, 이들을 각기 실험값과 비교하였다. 임계값까지의 수명예측은 실험과 비교하여 약 20%, 최종파손까지 약 65%의 오차가 발생하였다. 따라서, 전체 이론수명은 실험과 비교하여 약 45%의 오차를 발생하였다.

• The Journal of Korean Physical Therapy
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• 제20권2호
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• pp.1-10
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• 2008

Purpose: This study examines the effects of elastic band of resistance exercise for balance control of the elderly. Methods: Thirty of eighty participants in experiment subjects who demonstrated balance-impairment through the use of primary screening tests including the one leg standing test (OLST), functional reach test (FRT) and timed up and go (TUG) were selected as subjects. Fifteen subjects that underwent muscle-strengthening exercise using an elastic band were selected as the exercise group and fifteen subjects were selected as a control group. Subjects undertook a home-based exercise program three times per week for 9 weeks. Muscle strength, functional assessment and a balance test were quantitatively measured before and after the exercise regimen. Results: After muscle strengthening exercises, changes in maximal voluntary isometric contraction (MVIC) showed a significant increase in all of the lower extremity muscles of the exercise group subjects. There were statistically significant differences between the exercise and control groups for changes in the OLST, FRT and TUG, which are functional assessments of balance ability, and changes of the unit path length and circumference area, measurement items of quantitative analysis. In addition, from examining correlations between MVIC, balance ability, it was found that an increase of muscle strength in the hip joint group of muscles among the lower extremity muscles had greater improvement in correlation with balance ability in this elderly population. Conclusion: Resistance exercise using elastic bands had significant effects on muscle strengthening in elderly subjects, with a resultant increase of lower extremity muscle strength with significant improvement of balance ability.