• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.665-667
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• 2005

VIATRON TECHNOLOGIES has developed FE-RTP system that enables LTPS LCD and AMOLED manufacturers to produce poly-Si films at low cost, high throughput, and high yield. The system employs sequential heat treatment methods using temperature control and rapid thermal processor modules. The temperature control modules provide exceptionally uniform heating and cooling of the glass substrates to within ${\pm}2^a\;C$. The rapid thermal process that combines heating with field induction accelerates the treatment rates. The new FE-RTP system can process $730{\times}920mm$ glass substrates as thin as 0.4 mm. The uniform nature of poly-Si films produced by FE-RTP resulted in AMOLED panels with no laser-Muras. Furthermore, FE-RTP system also showed superior performances in other heat treatment processes involved in poly-Si TFT fabrications, such as dopant activation, gate oxide densification, hydrogenation, and pre-compaction.

• Korean Journal of Medicinal Crop Science
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• v.3 no.3
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• pp.233-239
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• 1995

The effects of media, growth regulators, low-temperature treatments, culture temperature and light were investigated to improve the callus induction and growth in the anther culture of Comus officinalis Sieb. et Zucco. The frequency of callus induction was more effective on WPM medium than MS medium, and it was highest as 54% in WPM medium supplemented with Img/L NAA. Callus growth was stimulated on MS medium supplemented with 2mg/L NAA. Effect of temperature and light on the callus induction and growth was highest as 62% in the treatment for 16/8 hrs. (light/dark) at $25^{\circ}C$ Ef­fect of low - temperature treatment on callus induction was highest as 19. 5% in the treatment for 36 hrs. at $4^{\circ}C$. For organization, green cells and rootings were promoted on MS medium supplemented with O. 5mg/L 2,4-D and 1 mg/L kinetin. The prevention of callus browning was effective on the medium con­taining $3{\sim}5mg/L$ ABA or 5mg/L $AgNO_3$. The supplement of ABA or $AgNO_3$,were maintained callus ac­tivity for 4-5 weeks and they were promoted the development of green cells.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.75-82
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• 1999

A compensation method of the motor parameters using zero sequence third harmonic voltage is presented for the speed sensorless vector control of the induction motor considering saturation of the flux. Generally, the air-gap flux of the saturated induction motor contains the space harmonic components rotating with the synchronous frequency of the motor. Because the EMF of the saturated induction motor contains the zero sequence harmonic voltages at the neutral point of the motor, those harmonic voltages can be used as a saturation index. In this work, the rotor flux observer is firstly designed for the speed sensorless vector control of induction motor. And a novel measurement method of the space harmonic voltage and a compensation method of th LPF(Low Pass Filter) are proposed. For compensating the non-linear variations of the magnetizing inductance depending on the saturation level of the motor, the dominant third harmonic voltage of the motor is used as a saturation function of the air-gap flux. And the variation of the stator resistance owing to the motor temperature can also be measured with the phase angle between the impressed voltage vector and the zero sequence voltage. The validity of the proposed parameter compensation scheme in the speed sensorless vector control using rotor flux observer is verified by the result of the simulations and the experiments.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.100-106
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• 2014

There is a growing need to introduce advanced pressure vessel steels with higher strength and toughness for the optimizatiooCn of the design and construction of longer life and larger capacity nuclear power plants. SA508 Gr.4N Ni-Cr-Mo low alloy steels have superior strength and fracture toughness, compared to SA508 Gr.3 Mn-Mo-Ni low alloy steel. Therefore, the application of SA508 Gr.4N low alloy steel could be considered to satisfy the strength and toughness required in advanced nuclear power plants. The purpose of this study is to characterize the microstructure and mechanical properties of SA508 Gr.4N low alloy steels. 1 ton ingot of SA508 Gr.4N model alloy was fabricated by vacuum induction melting followed by forging, quenching, and tempering. The predominant microstructure of the SA508 Gr.4N model alloy is tempered martensite having small packet and fine Cr-rich carbides. The yield strength at room temperature was 540MPa, and it was decreased with an increase of test temperature while DSA phenomenon occurred at around $288^{\circ}C$. Overall transition property of SA508 Gr.4N model alloy was much better than SA508 Gr.3 low alloy steel. The index temperature, $T_{41J}$, of SA508 Gr.4N model alloy was $-132^{\circ}C$ in Charpy impact tests, and reference nil-ductility transition temperature, $RT_{NDT}$ of $-105^{\circ}C$ was obtained from drop weight tests. From the fracture toughness tests performed in accordance with the ASTM standard E1921 Master curve method, the reference temperature, $T_0$ was $-147^{\circ}C$, which was improved more than $60^{\circ}C$ compared to SA508 Gr.3 low alloy steels.

• Genes and Genomics
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• v.40 no.12
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• pp.1259-1267
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• 2018

Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high commercial value due to its high nutritional values and favorable tastes. However, irregular bearing attributed to unstable flowering is a major ongoing problem for litchi producers. Previous studies indicate that low-temperature is a key factor in litchi floral induction. In order to reveal the genetic and molecular mechanisms underlying the reproductive process in litchi, we had analyzed the transcriptome of buds before and after low-temperature induction using RNA-seq technology. A key flower bud differentiation associated gene, a homologue of FLORICAULA/LEAFY, was identified and named LcLFY (GenBank Accession No. KF008435). The cDNA sequence of LcLFY encodes a putative protein of 388 amino acids. To gain insight into the role of LcLFY, the temporal expression level of this gene was measured by real-time RT-PCR. LcLFY was highly expressed in flower buds and its expression correlated with the floral developmental stage. Heterologous expression of LcLFY in transgenic tobacco plants induced precocious flowering. Meantime, we investigated the sub-cellular localization of LcLFY. The LcLFY-Green fluorescent protein (GFP) fusion protein was found in the nucleus. The results suggest that LcLFY plays a pivotal role as a transcription factor in controlling the transition to flowering and in the development of floral organs in litchi.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.506-513
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• 2021

The durability and safety of reinforced concrete structures significantly depend on the reinforcement conditions, concrete cover thickness, cracks, and concrete strength. There are two ways to accurately determine the information on reinforcing bars embedded in concrete - the local destructive method and the non-destructive rebar detection test. In general, the non-destructive rebar detection tests, such as the electromagnetic wave radar method, electromagnetic induction method, and radiation method, are adopted to avoid damage to the structural elements. The moisture content and temperature of concrete affect the dielectric constant, which is the electrical property of concrete, and cause interference in the non-destructive rebar detection test results. Therefore, in this study, the effects of the electromagnetic wave radar method and electromagnetic induction method have been analyzed according to the temperature and surface moisture content of concrete. Due to the technological advancement and development of equipment, the average error rate was less than 5% in the specimens at 24℃, irrespective of their operating principles. Among the tested methods, the electromagnetic induction method showed very high accuracy. The electromagnetic wave radar method indicated a relatively small error rate in the dry state than in the wet state, and exhibited a relatively high error rate at high temperatures. It was confirmed that the error could be reduced by applying the electromagnetic wave radar method when the temperature of the probe was low and in a dry state, and by using the electromagnetic induction method when the probe was in a wet state or at a high temperature.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.14-20
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• 1997

To increase the efficiency of the callus induction in anther culture of Schizandra chinensis, the effects of culture stage, low temperature pretreatment, growth regulators, sucrose and gelling agents were tested on Murashige and Skoog's medium. And the effects of ABA and $AgNO_3$ on organogenesis were investigated. The most suitable stage for anther culture was at the middle to late uninucleate stage, of which the flower size was $6.2{\pm}0.6{\times}4.0{\pm}0.4mm(Length{\times}width)$, and the frequency of callus induction was 13.3%. The effect of low-temperature pretreatment on callus induction was highest as 12.5% in the trearment for 8 days at $4^{\circ}C$. The combination of 1.0 mg/L 2, 4-D and 0.25 mg/L kinetin for callus induction was most effective as 8.3% among various media. The frequency of callus induction was excellent as 10.8% in 4% sucrose. Effect of gelling agents on callus induction was highest as 9.0% on 0.6% Gelrite medium. The prevention of callus browning was effective on the media supplemented with ABA and $AgNO_3$ and rooting was promoted on medium supplemented with 5 mg/L ABA. But shoot was not developed.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.3
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• pp.172-176
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• 2005

Modern automobiles are built with a steadily increasing variety of materials and semifinished products. The traditional composition of steel sheet and cast iron is being replaced with other materials such as aluminum and magnesium. But low formability of these materials has prevented the application of the automotive components. The formability can be enhanced by conducting the warm hydroforming using induction heating device which can raise the temperature of the specimen very quickly. The specimen applied to the test is A6061, A7075 extruded tubes which belong to the age-hardenable aluminum alloys. But in the case of A6061 age hardening occurs at room temperature or at elevated temperatures before and after the forming process. In this study the effects of the heating condition such as heating time, preset temperature, holding time during die closing and forming time on the hydroformability are analyzed to evaluate the phenomena such as dynamic strain hardening and ageing hardening at high temperatures after the hydroforming process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.85-91
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• 2015

A gasoline engine automobile uses high voltage generation of the ignition coil, igniting and burning mixed fuel in the combustion chamber, which drives the engine. When the electronic control unit intermits a current supplied to the power transistor, counter electromotive force with a low voltage is generated by self induction action in the ignition primary coil and a high voltage is induced by mutual induction action with the primary ignition coil in the second ignition coil. The high voltage is supplied to the ignition plug in the combustion chamber, causing a spark, igniting the compressed mixed fuel. If a very small defect occurs inside the insulating material when a voltage is applied in said ignition coil, the performance of the insulation material will get worse and breakdown by a partial discharge of corona discharge. Thus, in this experiment, we are to contribute to improve the performance and ensure the reliability of the ignition coil by investigating partial discharge characteristics according to the change of voltage and temperature when a voltage is applied to the specimen of the epoxy molding ignition coil.

• Journal of Power Electronics
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• v.3 no.2
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• pp.99-114
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• 2003

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation fur general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sine-wave PWM inverter with an automatic tuning machine parameter estimation schemes. In the first place, the sensorless vector control theory on the three-phase voltage source-fed inverter induction motor drive system is developed in slip frequency based vector control principle. In particular, the essential procedure and considerations to measure and estimate the exact stator and rotor circuit parameters of general purpose induction motor are discussed under its operating conditions. The speed regulation characteristics of induction motor operated by the three-phase voltage-fed type current controlled PWM inverter using IGBT's is illustrated and evaluated fur machine parameter variations under the actual conditions of low frequency and high frequency operations for the load torque. In the second place, the variable speed induction motor drive system, employing sensorless vector control scheme which is based on three -phase high frequency carrier PWM inverter with automatic toning estimation schemes of the temperature -dependent and -independent machine circuit parameters, is practically implemented using DSP-based controller. Finally, the dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.