• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.65-68
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• 2000

Polyethylene, has long history and is widely used, was researched due to good electrical properties by many authors. But PE under stress has the critical defects of space charge accumulation and tree growth, so various methods such as catalyst, additives and blend to improve these problems have been execute, of which we selected blending method. As in our previous papers we investigated electrical conduction, dielectric and AC dielectric breakdown characteristics, we did DC dielectric breakdown characteristics in this paper. We selected pure LLDPE, pure EVA and LLDPE films mixed with EVA as specimens, which were mixed with the weight percentages of 50, 60, 70 and 80[wt%] to be thin film. DC applying voltage speed was 500[V/sec]. The relation between dielectric breakdown characteristics and the variations of super structure due to mixing was investigated, and especially trap level at amorphous region, threshold energy increment of conductive electron at free volume were considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.22-23
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• 2006

Proton irradiation technology was used for improvement of switching characteristics of the PT-IGBT. Proton irradiation was carried out at 5.56 MeV energy with $1{\times}10^{12}/cm^2$ doze from the back side of the wafer. Characterization of the device was performed by I-V, breakdown voltage, threshold voltage, and turn-off delay time measurement. For irradiated device by 5.56 MeV energy, the breakdown voltage and the threshold voltage were 730 V and 6.5~6.6 V, respectively. The turn-off time has been reduced to 170 ns, which was original $6\;{\mu}s$ for the un-irradiated device.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.88-93
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• 2020

Based on the capture-emission energy (CEE) maps of CMOS devices, a physics-informed machine learning model for the bias temperature instability (BTI)-induced threshold voltage shifts and low frequency noise is presented. In order to incorporate physics theories into the machine learning model, the integration of artificial neural network (IANN) is employed for the computation of the threshold voltage shifts and low frequency noise. The model combines the computational efficiency of IANN with the optimal estimation of Gaussian mixture model (GMM) with soft clustering. It enables full lifetime prediction of BTI under various stress and recovery conditions and provides accurate prediction of the dynamic behavior of the original measured data.

• Journal of the Korean Society for Railway
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• v.13 no.5
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• pp.504-508
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• 2010

The development of high voltage Insulated Gate Bipolar Transistor (IGBT) have given new device advantage in the areas where they compete with conventional GTO (Gate Turnoff Thyristor) technology. The IGBT combines the advantages of a power MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) and a bipolar power transistor. The change of electrical characteristics for IGBT is mainly coming from the change of characteristics of MOSFET at the input gate and the PNP transistors at the output. The change of threshold voltage, which is one of the important design parameters, is brought by charge trapping at the gate oxide under the environment that radiation exists. The energy loss will be also studied as the inductance values are changed. In this paper, the electrical characteristics are simulated by SPICE, and compared for variation of inductance and threshold voltage based on IGBT.

• Journal of Nutrition and Health
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• v.30 no.8
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• pp.995-1008
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• 1997

This study was performed to investigate the change in taste perception during aging and its effects on dietary intake in Korean elderly. The subjects were female aged 65 through 90 in the Anyang area, and college women were included as a comparison group . Dietary intake of the elderly(n=155) and young subjects (n=38) was measured by a 3 day diet record. The taste threshold and 'just right' concentrations(JRC) for sweet and salty tastes were assessed by sensory evaluation . Sucrose solution (0.0.,0.4,0.6,0.8,1.0, 1.2%) and salt solution(0, 0.02, 0.03,0.06,0.09,0.12,0.15%) were used to establish thresholds. for JRC assessment, four suprathreshold sucrose concentrations of 5, 8, 11 and 14% in orange-pineapple flavored juice and salt concentrations of 0.20, 0.34, 0.50and 0.75% in beef stock were prepared. Mean intakes of energy, protein , vitamin A, thiamin , riboflavin, niacin ,calcium and iron of the elderly were below the Korean Recommended Dietary allowances. The elderly showed higher taste thresholds than young subjects of both sweet and salty tastes consumed less calories. Needs to bespecified. The older subjects having high threshold or JRCs for sweet and salty tastes consumed fewer calories from protein and fat. Pearson correlation coefficients was between JRC for sweet and salty tastes 0.54(p<0.01). The correlation coefficients between tastes threshold and nutrient intakes were very low for both age groups. Unlike the college women, in the elderly the JRC of sweet taste of the orange-pineapple juice were negatively correlated with intakes of energy, protein, fats, thiamin , riboflavin , niacin ,vitamin C , iron and consumption of meat and egg food groups (p<0.01). In summation age-related alterations in sweet and salty taste perception were observed in the elderly and dietary intakes of the elderly see to be influenced by these taste perception changes.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2287-2290
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• 2003

The electrical characteristics of power devices such as BJT (Bipolar Junction Transistor), and MOSFET (Metal Oxide Field Effect Transistor), etc, are altered due to impinging photon radiation and temperature in the nuclear or the space environment. In this paper, BJT and MOSFET are the two devices subjected to ${\gamma}$ radiation. In the case of BJT, the current gain (${\beta}$) and the collector to Emiter breakdown voltage ($V_{CEO}$) are the two main parameters considered. When it was subjected to ${\gamma}$ rays, the ${\beta}$ decreases as the dose level increases, whereas, $V_{CEO}$ gradually increases as the dose level increases. In the case of MOSFET, the threshold voltage is decreasing as the dose level increases. Here it has been observed the decent rate is an increasing function of the threshold voltage. The on-resistance does not change with respect to the dose. Both the devices recover back the original specification after the annealing is finished. No permanent damage has been occurred.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.443-448
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• 1998

With using artificial neural networks (ANNs), an analytical study related to the heated length effect on critical heat flux(CHF) has been carried out to make an improvement of the CHF prediction accuracy based on local condition correlations or table. It has been carried out to suggest a feasible criterion of the threshold length-to-diameter (L/D) value in which heated length could affect CHF. And within the criterion, a L/D correction factor has been developed through conventional regression. In order to validate the developed L/D correction factor, CHF experiment for various heated lengths have been carried out under low and intermediate pressure conditions. The developed threshold L/D correlation provides a new feasible criterion of L/D threshold value. The developed correction factor gives a reasonable accuracy fur the original database, showing the error of -2.18% for average and 27.75% for RMS, and promising results for new experimental data.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1059-1060
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• 2006

The creep behavior of Al-5vol.% SiC composite was investigated. The composite powder was produced by mechanical milling and hot extruded at $450^{\circ}C$ at ratio of 16:1. A creep test was carried out at a constant load at 598, 648, and 673 K. Using the steady-state equations, the threshold stress and the stress exponent of the creep as a function of temperature were determined. The stress exponent was found to be 3 at the temperature of 673 K and 8 at 598 and 648 K. The dependency of the threshold stress to temperature obeys the Arrhenius relationship with the energy term of $29\;kJ\;mole^{-1}$.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.445-451
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• 2010

This paper presents a threshold adaptation based voice query transcription scheme for music information retrieval. The proposed scheme analyzes monophonic voice signal and generates its transcription for diverse music retrieval applications. For accurate transcription, we propose several advanced features including (i) Energetic Feature eXtractor (EFX) for onset, peak, and transient area detection; (ii) Modified Windowed Average Energy (MWAE) for defining multiple small but coherent windows with local threshold values as offset detector; and finally (iii) Circular Average Magnitude Difference Function (CAMDF) for accurate acquisition of fundamental frequency (F0) of each frame. In order to evaluate the performance of our proposed scheme, we implemented a prototype music transcription system called AMT2 (Automatic Music Transcriber version 2) and carried out various experiments. In the experiment, we used QBSH corpus [1], adapted in MIREX 2006 contest data set. Experimental result shows that our proposed scheme can improve the transcription performance.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.46-48
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• 1989

In order to increase the efficiency of a bluegreen dye laser, the mixed dye method and separate dye method have been employed and the results were compared. By the mixed dye method(LD490+BBQ), the enhancement of laser energy was 193%, while by the separate dye method(LD490/BBQ), it was 90%, It was also found that the mixed dye method made the laser threshold energy decreased.