• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.911-913
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• 2008

In this work, nonvolatile memory (NVM) devices for system on panel of flat panel display (FPD) were fabricated using low temperature polycrystalline silicon (LTPS) thin film transistor (TFT) technology with an oxide-nitride-oxynitride (ONOn) stack structure on glass. The results demonstrate that the NVM devices fabricated using the ONOn stack structure on glass have suitable switching characteristics for data storage with a low operating voltage, a threshold voltage window of more than 1.8 V between the programming and erasing (P/E) states after 10 years and its initial threshold voltage window (${\Delta}V_{TH}$) after $10^5$ P/E cycles.

• ETRI Journal
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• 제27권4호
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• pp.449-452
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• 2005

The electrical characteristics of solid state devices such as the bipolar junction transistor (BJT), metal-oxide semiconductor field-effect transistor (MOSFET), and other active devices are altered by impinging photon radiation and temperature in the space environment. In this paper, the threshold voltage, the breakdown voltage, and the on-resistance for two kinds of MOSFETs (200 V and 100 V of $V_{DSS}$) are tested for ${\gamma}-irradiation$ and compared with the electrical specifications under the pre- and post-irradiation low dose rates of 4.97 and 9.55 rad/s as well as at a maximum total dose of 30 krad. In our experiment, the ${\gamma}-radiation$ facility using a low dose, available at Korea Atomic Energy Research Institute (KAERI), has been applied on two commercially available International Rectifier (IR) products, IRFP250 and IRF540.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.514-523
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• 2023

The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

• 대한기계학회논문집
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• 제19권9호
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• pp.2105-2113
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• 1995

The compressive tests under impact conditions were performed to establish a design guide for impact damage tolerance. The composition of layup was selected for the real cases of composite aircraft structure. The energy level of visible of visible damage threshold was determined as 7 Joules. It was found that the normalized bending stiffnesses in the direction of closely fixed boundary affected the area of damage. Graphite/epoxy used in the tests exhibited 60% reduction in compression strength at the energy level of visible damage threshold. Wet-conditioned specimens represented 9% reduction in residual compressive strength in comparison with room temperature ambient specimens. In this study, a design factor of 2.1 was proposed for the low velocity impact damage.

• 한국환경과학회지
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• 제30권1호
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• pp.45-55
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• 2021

In this study, the odor of the parts and the odor of the surrounding environment were classified and verified. In order to increase the reliability of odor quantitative/qualitative analysis, the selection criteria for 5 sensory evaluators were established, and the n-Butanol control solution for each odor intensity was periodically trained to recognize the odor intensity before sensory evaluation. In addition, although various odor thresholds have been used through several studies, verification of whether the odor intensity value obtained through GC/MSD analysis is similar to the degree to which a person directly smells and feels it. It is important to select the odor threshold that has the best correlation with the odor intensity calculated by the person smelling the odor. Finally, sampling and measuring flowing airflow and temporary odors such as odor component analysis was experimentally difficult due to limited collection space and differences in concentration of generated components. In this study, a quantitative analysis was made possible by using the low temperature concentration (cooling) trap method. Through this, it was confirmed that the correlation with the actual odor intensity was not caused by the product itself, but by the environmental factor discharged from the product after creating the odor environment.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.163-168
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• 2014

Bottom gate thin-film transistors were fabricated using solution processed IGZO channel layers with various gallium composition ratios that were annealed on a hot plate. Increasing the gallium ratio from 0.1 to 0.6 induced a threshold voltage shift in the electrical characteristics, whereas the molar ratio of In:Zn was fixed to 1:1. Among the devices, the IGZO-TFTs with gallium ratios of 0.4 and 0.5 exhibited suitable switching characteristics with low off-current and low SS values. The IGZO-TFTs prepared from IGZO films with a gallium ratio of 0.4 showed a mobility, on/off current ratio, threshold voltage, and subthreshold swing value of $0.1135cm^2/V{\cdot}s$, ${\sim}10^6$, 0.8 V, and 0.69 V/dec, respectively. IGZO-TFTs annealed at $300^{\circ}C$, $350^{\circ}C$, and $400^{\circ}C$ were also fabricated. Annealing at lower temperatures induced a positive shift in the threshold voltage and produced inferior electrical properties.

• Transactions on Electrical and Electronic Materials
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• 제1권2호
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• pp.7-11
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• 2000

a-Si:H and poly-Si TFT(thin film transistor) characteristics were investigated using an inverted staggered type TFT. The TFT an as-grown a-Si:H exhibited a low field effect mobility, transconductance, and high gate threshold voltage. The poly-Si films were achieved by using an isothermal and RTA treatment for glow discharge deposited a-Si:H films. The a-Si:H films were cystallized at the various temperature from 600$^{\circ}C$ to 1000$^{\circ}C$. As anneal temperature was elevated, the TFT exhibited increased g$\sub$m/ and reduced V$\sub$ds/. V$\sub$T/. The poly-Si grain boundary passivation with grain boundary trap types and activation energies as a function of anneal temperature. The poly-si TFT showed an improved I$\sub$nm//I$\sub$off/ ratio of 10$\^$6/, reduced gate threshold voltage, and increased field effect mobility by three orders.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.320-325
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• 2001

In this study, CT specimen were prepared from Pressure Vessel Steel which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -8$0^{\circ}C$, -10$0^{\circ}C$ and -12$0^{\circ}C$ and in the range of stress ratio of 0.05 and 0.3 by means of opening mode displacement. At the constant street ratio, the threshold stress intensity factor range ΔK$_{th}$ in the early stage of fatigue crack growth(Region I) and stress intensity factor range ΔK in the stable of fatigue crack growth(Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm do/dN -ΔK in RegionII, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate do/dN is rapid in proportion to descending temperature in Region IIand the cryogenic-brittleness greatly affect a material with decreasing temperature.e.greatly affect a material with decreasing temperature.

• 대한조선학회논문집
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• 제45권5호
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• pp.530-537
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• 2008

Austenitic stainless steels(SUS 304, SUS 316), which are used for safety control valve of LNG carrier, are occasionally exposed in the cryogenic environment. In this regards, it is required to evaluate the mechanical characteristics under the low temperature environment. In this study, a series of uniaxial tensile test was carried out varying temperature for austenitic stainless steel. The phenomena of the strain-induced plasticity have been observed on the all temperature ranges. The critical value for threshold of 2nd hardening due to the phase transformation induced plasticity as well as the increase of hardening have been reported. The summarized experimental results would be used for the validation of numerical techniques applicable for the nonlinear hardening behavior of austenitic stainless steel under the cryogenic temperature environment.

• 한국해양공학회지
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• 제15권3호
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• pp.100-106
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• 2001

In this study, CT specimens were prepared from Pressure Vessel Steel which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -10$0^{\circ}C$ and -12$0^{\circ}C$ and in the range of stress ratio of 0.05 and 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\Delta}K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range ${\Delta}K$ in the stable of fatigue crack growth (Region II) was increased in proportion to descent temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN $-{\Delta}K$ in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate da/dN in proportion to descending temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.