• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.557-558
• /
• 2006

In this paper, the hysteresis characteristics by bias stress in organic thin film transistors using inkjet printing were investigated. Electron trapping increased threshold voltage for positive gate bias stress and hole trapping decreased threshold voltage for negative gate bias stress. From these phenomena, highly reproducible measurement method which minimized threshold voltage shift by choosing the proper range of gate voltage was suggested. Using this measurement method, we found that electron trapping as well as hole trapping had important influence on hysteresis characteristics.

• 디지털융복합연구
• /
• 제16권4호
• /
• pp.95-105
• /
• 2018

본 연구는 구미 클러스터내 기술지식 교류 네트워크에서 기술적 급진성에 대한 네트워크 폐쇄와 구조적 공백의 역할을 실증적으로 검증한 연구이다. 분석을 위해 협회*기업(2-mode)네트워크 자료를 기업*기업(1-mode) 네트워크 자료로 변환하여 2,550개 기업 네트워크를 구축하였다. 또한 기업의 특성을 조사하기 위해 구미국가산업단지에 있는 기업을 대상으로 랜덤추출을 통해 101개 기업에게 설문을 실시하였으며 최종적으로는 86개 기업을 수집하였다. 분석을 위해, 네트워크 폐쇄와 구조적 공백의 사회네트워크 분석 지표인 네트워크 밀도와 효율성이 높은 수준의 다중공선성을 갖고 있어 능형회귀분석을 이용하였다. 분석결과 구조적 공백은 기업의 급진적 혁신에 긍정적인 영향을 미치는 것으로 나타났으며, 네트워크 밀도는 급진적 혁신에 부정적인 영향을 미치는 것으로 나타났다. 본 연구는 과거의 개념적인 논의와 문헌연구에 기반 했던 네트워크 패쇄와 구조적 공백의 논쟁에 실증적 증거 제시하는데 공헌하고 나아가 급진적 혁신을 달성하기 위한 사회적 자본의 구축 전략 수립에 도움을 준다. 향후 연구에서는 다양한 네트워크의 구조적 특성을 찾아내려는 노력이 필요할 것이며, 기술 지식의 특성, 혁신 유형, 네트워크 폐쇄와 구조적 공백의 상호작용 등에 관심을 두어야 할 것이다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.324-327
• /
• 2000

In this paper, the effects of negative and positive bias stress on p-channel poly-Si TFT's fabricated by excimer laser annealing have been investigated After positive and negative bias stress, transcon-ductance(g$_{m}$) is increased because of a reduction of the effective channel length due to the injected electron in the gate oxide. In the positive bias stress, the injection of hole is appeared after stress time of 3600sec and g$_{m}$ is decreased. On the other hand, the gate voltage at the maximum g$_{m}$, S-swing and threshold voltage(V$_{th}$) are decreased because of the interface state generation due to the injection of electrons into the gate oxide.e.ide.e.

• 상하수도학회지
• /
• 제9권4호
• /
• pp.87-96
• /
• 1995

The Electron/Hole Pair is generated when the activation energy produced by ultraviolet ray illuminates to the semiconductor and OH- ion produced by water photocleavage reacts with positive Hole. As a results, OH radical acting as strong oxidant is generated and then Photocatalytic oxidation reaction occurs. The photocatalytic oxidation can oxidate the non-degradable and hazardous organic substances such as pesticides and aromatic materials easier, safer and shorter than conventional water treatment process. So in this study, many factors influencing the oxidation of chlorophenols, such as inorganic electrolytes addition, change of oxygen and nitrogen atmosphere, temperature, pH, oxygen concentration, chlorophenol concentration, were throughly examined. According to the experiments observations, it is founded that the rate of chlorophenol oxidation follows a first-order reaction and the modified Langmuir-Hinshelwood relationship. And the photocatalytic oxidation occurs only when activation energy acting as Electron/Hole generation, oxygen acting as electron acceptor to prevent Electron/Hole recombination, $TiO_2$ powder acting as photocatalyst are present. The effects of variation of dissolved oxygen concentration, temperature and inorganic electrolytes concentration on 2-chlorophenol oxidation are negligible. And the lower the organic concentration, the higher the oxidation efficiency becomes. Therefore, the photocatalytic oxidation is much effective to oxidation of hazardous substances at very low concentration. The oxidation is effective in the range of 0.1 g/L-10 g/L of $TiO_2$. Finally when the ultra-violet ray is illuminated to $TiO_2$, the surface characteristics of $TiO_2$ change and Adsorption/Desorption reaction on $TiO_2$ surface occurs.

• 대한핵의학회지
• /
• 제19권1호
• /
• pp.73-75
• /
• 1985

Acute transient synovitis of the hip presents clinically pain and limping. But in the majority of the cases, definite positive findings are not manifest in roentgenogram in its early phase. However radionuclide bone imaging combines with the assessment of vascularization and bone tracer uptake is of great value in solving this diagnostic problem. The materials for this study consisted of 29 children with acute transient synovitis of the hip, characterized by symptoms and physical signs of an arthritis, negative X-ray findings and disappearance of all symptoms and signs within a short period of time. They were twenty males and 9 females and age ranged from 1 to 12 years. We took pelvic reontgenogram in AP and frog-leg views. After intravenous bolus injection of 10 to 15 mCi of $^{99m}Tc-methylene$ diphosphonate, 24 sequential image of the pelvis was taken at 2-second interval for blood flow study. The scintigrams were made using a gamma camera with high resolution parallel hole collimator. Blood pool imaging was obtained at 2 minutes after tracer administration. After 3 hours, static images were taken and then closeup image of the hip using pin-hole collimator was followed. The results were as follows: 1) Bone scintigram was much more sensitive than conventional roentgenogram in diagnosis of acute transient synovitis of the hip. 2) Three-phase imagings showed increased vascular activities in blood pool scintigrams in 96%. 3) Pin-hole imaging showed increased tracer uptake in the regional bones of the hip, par ticularly in the medial aspect of femoral head and acetabulum. 4) We confirmed that three-phase imaging reinforced with pin-hole technique were very useful in diagnose of acute transient synovitis of the hip.

• 한국조경학회지
• /
• 제21권1호
• /
• pp.13-30
• /
• 1993

The purpose of this study was to present data to the landscape planning and design through analyzing correlation between visual preference of users and nonusers and the landscape of hole in golf couses. Stimulus objects were selected from the 18 holes in Tae-gu Country Club. Preference value was judged through photo simulation by 35 subjects photographed at Tee and Interpoint (IPI, IP2), and classified into three landscape types and nine landscape components from photo analysis by researcher. For test of difference between groups toward each stimulus, t-test was used, and Duncantest, Correlation analysis for finding out correlation between preference degree and the landscape of each hole. The results of this study were as follows: As a result of analysis of preference value between groups for each hole, it has been shown that there was scarcely difference with each other. Form the relation between preference degree and spacial structure of hole, the holes making up a superior preference group have been shown that the greater part of the holes had a downward slope or a gentle slope mostly and then a visible ratio of fairway was high, and had diversified scenery by a lotus pond, a solitary planting tree, the roll of a fairway, facilities for convenience, etc. The holes making up a low-ranking preference group have been shown that the greater part of the holes had upward slope or a similar slope to it and had characteries of the bad condition of lawn, the nearby factories and odors, the monotonous scenery of a fairway, an unreasonable mixing of holes, etc. From the relation between preference degree and landscape components forming hole, it has been shown that the preference degree between users and nonusers had positive correlation to the occupied ratio of space of landscape components at Tee and Approach. At Tee, it has been shown that the preference degree of two groups were related with a lawn surface of fairway negatively, a lotus pond, a sky positively, and the preference degree of nonusers was related with iron-top for electric transmission positively. At Approach, it has been shown that the preference degree of two groups were related with iron-top for electric transmission negatively, and the preference degree of nonusers was related with a building positively. From the relation between preference degree group to each hole and the occupied ratio of space of landscape types, it has been shown that the constituent ratio of a high-ranking group was 1:2.4:2.2 and a low-ranking group was 1:4.1:5.1 among vertical type, horizontal type and background at Tee, but the constituent ratio of space of a high-ranking group was similar to a low-ranking group at Approach.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.84-87
• /
• 2001

Space charge formation at high temperature was investigated in several polymers using pulsed electro-acoustic (PEA) method. In SXLPE, homocharge is found and increased as an increase of temperature. In a charge of polarity of poling voltage(positive to negative), space charge mainly cause of hole injection. In Ionomer, heterocharge is found because of ion. As an increase of temperature heterocharge is also increased. In PET, As an increase of temperature homocharge is decreased.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2591-2596
• /
• 2007

The effect of incidence angle on the three-dimensional flow and aerodynamic loss in the downstream region of a high-turning turbine rotor blade has been investigated with a straight miniature five-hole probe. The incidence angle is changed to be +10, +5, 0, -10, -20, -30 and -40 degrees. The results show that the positive incidence reinforces the three-dimensional vortical flows within the turbine passage including the passage vortex, but the negative incidence weaken them significantly. A small increment in the positive incidence angle results in a remarkable aerodynamic loss increase, while increasing the incidence angle in the negative range leads to a very small change in the aerodynamic loss.

• 한국농공학회지
• /
• 제15권2호
• /
• pp.2980-3001
• /
• 1973

Nozzle is a part of sprayer and is consists of several elements; swirl plate, vortexchamber, cap and body. The travelling distance of sprayed particles is important in the wide reach nozzle. The factors to influence the travelling distance of the sprayed particles may be the helical angle of swirl plate, the distance of vortex hamber, the slope and the size of cap hole. The study was conducted to examine the effects of these factors on the travelling distance. The results of this study are summarized as follows; 1) There was higher positive correlation(+0.96) between the maximum travelling distance for which amount of sprayed particles was 5cc/cm min. and centro-position of the travelling distance. 2) There was a higher positive correlation(+0.85) between total discharge of sprayed particles and the centro-position of the travelling distance. 3) Main effects and interaction effects of helical angle, pressure, vortex chamber distance and cap slope were significantly affected the travelling distance of sprayed particles. 4) Main effects of helical angle, pressure and cap slope were especially highly significant to influence the travelling disance. 5) Helical angle, pressure, vortex chamber distance and cap slope influenced spraying forward velocity of dise hole, among which cap slope and pressure of nozzle was the most important factors. 6) Effect of change of helical angle on the travelling distance of sprayed particles, was generally a quadratic, the least value of the distance being showed about $45^{\circ}$ and the largest at about $15^{\circ}\;and\;55^{\circ}$, the decreasing rate of the change between $15^{\circ};and\;25^{\circ}$ was very small. 7) Effect of change of pressure on the travelling distance sprayed particles was generally a linear, the increasing rate of the charge was about 1.68, which was the most effective compared to the change of the other factors. 8) Effect of change of vortex chamber distance on the spraying distance was also generally a linear, the increasing rate being about 0.16, which was the least effective. 9) Effect of change of cap slope on the travelling distance was also generally a linear, the increasing rate was about 0.61 and its effect was about medium.

• 생명과학회지
• /
• 제24권3호
• /
• pp.290-296
• /
• 2014

이 연구의 목적은 mice를 이용하여 elevated plus-maze (EPM) test와 hole-board test를 통해 quercetin의 잠재적인 항불안 작용을 확인하고자 함이다. Quercetin을 1.25, 2.5, 5나 10 mg/kg의 용량으로 각각 행동시험을 측정하기 1 시간 전에 ICR mice에 경구투여하였다. 대조군은 동일한 양의 10% Tween 80을 투여하였고 양성대조군으로 buspirone 2 mg/kg을 투여하였다. Quercetin을 단회 투여하여 EPM test를 실시한 결과, 5 mg/kg 용량에서 open arm에 머문 시간 및 진입한 횟수의 백분율이 control group과 비교하여 통계적으로 유의성 있게 증가하였다(p<0.05). 또한 quercetin을 투여하여 hole-board test를 실시한 결과, 5 mg/kg 용량에서 구멍에 머리를 넣은 횟수가 control group과 비교하여 통계적으로 유의성 있게 증가하였다(p<0.05). 또한 quercetin와 flumazenil ($GABA_A$ antagonist), WAY-100635 ($GABA_{A-{\rho}}$ antagonist) 또는 trans-4-aminocrotonic acid ($GABA_{A-{\rho}}$ agonist)를 병용투여하여 elevated plus-maze를 실험을 하여 신경계와의 관계를 확인한 결과, trans-4-aminocrotonic acid에서만 quercetin의 항불안 작용이 차단되었음을 확인 할 수 있었다. 결론적으로, 본 연구의 결과에서 quercetin이 elevated plus-maze 및 hole-board test, horizontal wire test, open field test를 통하여 locomotor activity 및 근육이완이나 진정 등의 부작용이 없으면서 우수한 항불안 작용을 가지는 소재라고 생각되며 이러한 작용이 특히 GABA 신경계와 관련이 있음을 시사하고 있다.