• Journal of Information Display
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• 제10권4호
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• pp.175-179
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• 2009

As the physical properties of nematic liquid crystals vary with respect to temperature, the performances of liquid crystal displays (LCDs) are highly dependent on temperature. Additionally, it is well known that the electro-optic characteristics of LCDs, such as transmittance and threshold voltage, also rely on the LCD switching modes. The temperature dependence of the electro-optic characteristics of the wide-viewing-angle LCD modes, such as in-plane switching (IPS), multidomain vertical alignment by patterned electrode (PVA), and fringe-field switching (FFS), have been studied, and the results showed that the FFS mode has lower temperature dependence compared to the IPS and PVA modes. Since the liquid crystal (LC) reorients in different ways in each mode, this result is associated with the temperature dependence of LC's bend and twist elastic constants, and also with the position of the main reorientation, either in the middle or on the surface of the LC layer.

• 한국응용곤충학회지
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• 제43권2호
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• pp.111-116
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• 2004

목화진딧물 발육실험은 15-35$^{\circ}C$, 습도는 60-70%, 광주기는 16：8 (L：D h)에서 수행 하였다. 진딧물 약충 사망률은 초기 1-2령의 사망률이 대부분을 차지하고, 온도의 상승에 따라 사망률이 높아져 32.5$^{\circ}C$에서 36%였으며, 35$^{\circ}C$에서는 1-2령의 사망률이 44%, 3-4령이 56%로 이 온도에서는 진딧물의 발육이 이루어지지 많았고, 3-4령의 사망률이 1-2령의 사망률보다 높게 나타난다. 전체약충의 온도별 발육기간을 보면 15-3$0^{\circ}C$까지 온도의 상승에 따라 발육기간이 11.5에서 4.6일로 짧아지는 경향을 보였고, 고온의 영 향을 받은 것으로 생각되는 32.5$^{\circ}C$에서는 오히려 발육기간이 5.5일로 길어졌다. 발육영 점 온도는 5.$0^{\circ}C$이였고, 유효적 산온도는 106.8일도였다. 온도별 발육율은 변형된 Sharpe와 DeMichele의 비 선형 모형 에 잘 적합되었다. 발육단계별 발육기간을 표준화하여 누적시킨 값들은 3개의 변수를 갖는 Weibull function에 적합되었다.

• 대한기계학회논문집A
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• 제37권3호
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• pp.333-338
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• 2013

본 논문에서는 쇼트피닝 가공된 Alloy 600 재료의 고온환경하에서의 압축잔류응력 및 피로거동에 대해 연구하였다. 연구에 사용된 Alloy 600 재료는 원자력발전소에서 사용되는 주요부품 소재이며, 피닝가공으로 형성된 압축잔류응력은 응력부식균열(SCC; Stress Corrosion Cracking)의 발생을 크게 억제하는 것으로 알려져 있다. 현실성 있는 실험결과를 획득하기 위하여 실제 국내 원자력 발전소 주요부품의 사용온도를 포함한 고온 환경에서 피로특성 및 압축잔류응력을 평가하였다. 연구결과 약 $538^{\circ}C$이하에서는 피닝가공 효과가 존재하는 것으로 파악되었다. 피로수명은 $538^{\circ}C$ 까지 유지되는 것으로 분석되었으며, $538^{\circ}C$ 에서의 압축잔류응력은 상온에서의 값에 비하여 68.2%를 유지하였다. 본 연구결과는 원자력발전소의 안전 및 신뢰성 확보에 기초자료로 활용될 것으로 기대된다.

• 대한금속재료학회지
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• 제48권9호
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• pp.856-860
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• 2010

Silver nanoparticles were formed on silica substrates through thin film dewetting at high temperature. The microstructural and morphological evolution of the particles were characterized as a function of processing variables such as initial film thickness, annealing time, and temperature. Silver thin films were deposited onto the silica using a pulsed laser deposition system and annealed in reducing atmosphere to induce agglomeration of the films. The film thicknesses before dewetting were in the range of 5 to 25 nm. A noticeable agglomeration occurs with annealing at temperatures higher than $300^{\circ}C$, and higher annealing temperature increases particle size uniformity for the same film thickness sample. Average particle size linearly correlates to the film thickness, but it does not strongly depend on annealing temperature and time, although threshold temperature for complete dewetting increases with an increase of film thickness. Lower annealing temperature develops faceted surface morphology of the silver particles by enhancing the growth of the low index crystal plane of the particles.

• 한국응용곤충학회지
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• 제41권3호
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• pp.205-209
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• 2002

주홍날개들명나방(Udea ferrugalis)의 온도별(10, 15, 18, 20, 23, 25, 27, 3$0^{\circ}C$) 발육과 생식에 미치는 은도영향에 대하여 조사하였다. 난, 유충, 용기간은 고온에서 짧은 경향이었고, 1$0^{\circ}C$에서는 난과 용 발육은 완료되지 않았다. 각 태별 발육영접온도는 난이 9.5$^{\circ}C$, 유충 9.6$^{\circ}C$ 그리고 용은 11.9$^{\circ}C$이었고, 유효적산온도는 각각 87.9, 200.9, 119.7일도이었다. 산란전기간과 성충수명은 15$^{\circ}C$에서 10.9일, 25.2일이었으나, 23$^{\circ}C$에서는 2.5일, 7.3일, 3$0^{\circ}C$에서는 1.7일, 5.3일로써 온도가 높아질수록 그 기간이 짧았다. 평균산란수는 2$0^{\circ}C$와 23$^{\circ}C$에서 가장 많았다. 세대당 순증식율은 (Ro) 2$0^{\circ}C$에서 265.4로써 가장 높았고, 내적자연증가율은(r$_{m}$ ) $25^{\circ}C$에서 0.247로 가장 높았다. 이 결과로써 주흥날개들명나방의 발육과 생식에 적합한 온도는 2$0^{\circ}C$에서 23$^{\circ}C$이었다.

• 한국응용곤충학회지
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• 제55권4호
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• pp.453-457
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• 2016

본 실험은 갈색날개매미충의 난괴 채집시기별 부화율, 2011년부터 2014년까지 부화율과 부화시기, 그리고 발육에 미치는 온도의 영향을 조사하였다. 갈색날개매미충 알은 11월부터 익년 3월까지 채집시기가 늦어질수록 부화율이 높아지는 경향이며, 부화기간은 차이가 없었다. 온도별 부화 소요기간은 15, 18, 21, 24, 27, $30^{\circ}C$에서 각각 51.2, 31.3, 24.8, 19.4, 17.1, 19.4일이었으며 $18{\sim}27^{\circ}C$ 범위에서 70% 이상의 부화율을 보였다. 전남 구례지역에서 갈색날개매미충 월동 알의 부화시기는 2011년보다 2014년에 9일이 빨라졌으며, 겨울철 평균온도가 높았던 해에는 부화율이 높아지는 경향이었다. 부화약충부터 5령 약충까지 온도별 발육기간은 18, 21, 24, $27^{\circ}C$(습도 40~70%, 광조건 14L:10D)에서 각각 82.8, 58.0, 45.8, 39.6일로 온도가 높을수록 발육기간은 짧아졌는데, $30^{\circ}C$에서는 4령 이후 모두 사멸하여 시험온도중 약충의 발육최적온도는 $27^{\circ}C$이었다. 알에서부터 4령 약충까지의 온도와 발육속도와의 관계식은 Y = 0.0015 X - 0.014이며, 발육영점온도는 $9.3^{\circ}C$, 유효적산온도는 693.3일도였다. 발육영점온도는 4령 약충이 $3.8^{\circ}C$로 가장 낮았다.

• The Plant Pathology Journal
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• 제33권2호
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• pp.206-211
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• 2017

The effect of temperature on the rate of systemic infection of potatoes (Solanum tuberosum L. cv. Chu-Baek) by Potato virus Y (PVY) was studied in growth chambers. Systemic infection of PVY was observed only within the temperature range of $16^{\circ}C$ to $32^{\circ}C$. Within this temperature range, the time required for a plant to become infected systemically decreased from 14 days at $20^{\circ}C$ to 5.7 days at $28^{\circ}C$. The estimated lower thermal threshold was $15.6^{\circ}C$ and the thermal constant was 65.6 degree days. A systemic infection model was constructed based on experimental data, using the infection rate (Lactin-2 model) and the infection distribution (three-parameter Weibull function) models, which accurately described the completion rate curves to systemic infection and the cumulative distributions obtained in the PVY-potato system, respectively. Therefore, this model was useful to predict the progress of systemic infections by PVY in potato plants, and to construct the epidemic models.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.186-189
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• 2006

The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and room temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing process. The OTFT array with dielectric layer and organic active semiconductor layer formed at room temperature or at a temperature lower than $40^{\circ}C$. The microcontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a big dielectric.

• International Journal of Aeronautical and Space Sciences
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• 제7권1호
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• pp.13-26
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• 2006

When the stagnation temperature of a perfect gas increases, the specific heat for constant pressure and ratio of the specefic heats do not remain constant any more and start to vary with this temperature. The gas remains perfect: its state equation remains always valid, with exception that it will be named by calorically imperfect gas. The aim of this research is to develop the relations of the necessary thermodynamics and geometrical ratios. and to study the supersonic flow at high temperature. lower than the threshold of dissociation. The results are found by the resolution of nonlinear algebraic equations and integration of complex analytical functions where the exact calculation is impossible. The dichotomy method is used to solve the nonlinear equation. and the Simpson algorithm for the numerical integration of the found integrals. A condensation of the nodes is used. Since. the functions to be integrated have a high gradient at the extremity of the interval of integration. The comparison is made with the calorifcally perfect gas to determine the error made by this last. The application is made for the air in a supersonic nozzle.

• Journal of Advanced Marine Engineering and Technology
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• 제29권4호
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• pp.426-435
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• 2005

The lightness of components required in automobile and machinery industries is requiring high strength of components. Therefore this requirement is accomplished as the process of shot-peening method that the compressive residual stress is made on the metal surface as one of various improvement methods. Special research is, therefore, needed about compressive residual stress on the metal surface in the process of shot-peening method. Therefore, in this paper the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in environmental condition(temperature) and mechanical condition(shot velocity, stress ratio) was investigated with considering fracture mechanics. By using the methods mentioned above, the following conclusions have been drawn. (1) The fatigue crack growth rate(da/dN) of the shot-peened material was lower than that of the un-peened one. In high temperature range. fatigue crack growth rate decreased with increasing temperature range, while fatigue crack growth rate increased by decreasing temperature in low temperature. (2) Fatigue life shows more improvement in the shot-peened material than in the un-peened material. And compressive residual stress of surface on the shot-peen processed operate resistance force of fatigue crack propagation.