• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.665-667
• /
• 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.

• 한국약용작물학회지
• /
• 제3권3호
• /
• pp.233-239
• /
• 1995

산채막(山菜莫)(Cornus officinalis Sieb. et Zucc. )의 조직배양(組織培養)을 위한 기초적(基礎的) 연구(硏究)로서 체배양(諦培養)에 미치는 배지(培地), 생장조절제(生長調節劑), 저온(低溫) 전처리(前處理), 배양온도(培養溫度) 및 광(光)의 영향(影響)을 검토(檢討)한 결과(結果)는 다음과 같다. 1. 캘러스 형성율(形成率)은 MS배지(培地)보다 WPM배지(培地)에서 좋은 반응(反應)을 보였으며, Img/L NAA를 첨가(添加)한 WPM배지(培地)에서 54%로 가장 높았고, 캘러스 생장(生長)은 2mg/L NAA를 첨가(添加)한 MS배지(培地)에서 좋았다. 2. 약(約)의 배양온도(培養溫度) 및 광(光)의 영향(影響)은 $25^{\circ}C$, 16시간 명배양(明培養)이 62%의 가장 높은 캘러스 형성율(形成率)을 보였다. 3. 캘러스 형성(形成)에 미치는 약(約)의 저온(低溫) 전처리(前處理) 효과(效果)는 $4^{\circ}C$, 36시간 처리(處理)에서 19.5%로 가장 높았다. 4. 기관분화(器官分化)를 위한 적정배지(適正培地)로는 0. 5mg/L 2, 4-D와 1mg/L kinetin을 첨가(添加)한 MS배지가 녹점형성(綠點形成) 및 뿌리분화를 촉진(促進)하였다. 5. 캘러스 양변화(楊變化) 방지(防止)를 위하여는 3-5mg/L ABA 와 5mg/L $AgNO_3$의 첨가(添加)가 효과적이었으며, 캘러스 활력(活力)이 높아 녹점형성(綠點形成)을 촉진(促進)하였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제48권2호
• /
• pp.75-82
• /
• 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.

• 한국압력기기공학회 논문집
• /
• 제10권1호
• /
• pp.100-106
• /
• 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
• /
• 제40권12호
• /
• pp.1259-1267
• /
• 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.

• 한국건설순환자원학회논문집
• /
• 제9권4호
• /
• pp.506-513
• /
• 2021

철근콘크리트 구조물의 내구성 및 안전성은 콘크리트의 균열 및 강도와 더불어 철근의 배근상태나 콘크리트 피복 두께에 크게 의존한다. 콘크리트 내에 매립되어 있는 철근 정보를 정확히 파악하는 방법엔 국부 파괴법과 비파괴 철근 탐사 시험이 있다. 일반적으로 부재 손상을 최소화하기 위해 비파괴 철근 탐사 시험을 통해 파악하며, 비파괴 철근 탐사 시험에는 전자파레이더법, 전자기유도법, 방사선법 등이 있다. 콘크리트의 함수율과 온도는 콘크리트의 전기적 특성인 유전율에 영향을 미쳐 비파괴 철근 탐사 시험 결과에 간섭을 방생시킨다. 따라서 본연구에서는 콘크리트의 표면수율과 온도에 따라 전자파레이더법과 전자기유도법이 받는 영향을 분석하였다. 장비와 기술의 발달로 원리와 상관없이 24℃ 시험체에서는 평균 오차율이 5% 이하로 나타났으며 특히 전자기유도법의 경우 매우 높은 정확성을 갖는 것을 확인하였다. 전자파레이더법은 습윤상태보다 건조상태에서 상대적으로 오차율이 작은 특성을 나타내었으며, 고온에서는 다소 높은 오차율이 나타났다. 탐사 대상의 온도가 낮고 건조한 경우 전자파레이더법을 적용하고, 탐사 대상이 습윤상태이거나 고온에서는 전자기유도법을 사용하여 오차를 감소시킬 수 있음이 확인되었다.

• 한국약용작물학회지
• /
• 제5권1호
• /
• pp.14-20
• /
• 1997

오미자 약배양을 이용한 우량계통 조기고정 및 순계유지를 위하여, 약배양 효율에 미치는 배양시기, 저온전처리, 생장조절제 및 sucrose 농도, 배지응고제, 그리고 기관분화에 미치는 ABA, $AgNO_3$ 등의 영향을 조사하였던 바, 얻어진 결과는 다음과 같다. 1. 약배양 시기는 화뢰의 장폭이 $6.2{\times}4.0mm$ 크기의 1핵성 소포자 중기 - 후기의 약에서 13.3%의 가장 높은 캘러스 형성율을 보였다. 2. 화뢰의 저온전처리에 따른 캘러스 형성율은 $4^{\circ}C$, 8일 처리에서 12.5%로 가장 높았다. 3. 캘러스 형성에 미치는 생장조절제의 영향은 1.0mg/L 2, 4-D와 0.25mg/L kinetin 첨가배지에서 8.3%로 가장 높았다. 4. 배지내 sucrose농도에 따른 캘러스 형성율은 4% 첨가배지에서 10.8% 로 가장 높았다. 5. 캘러스 형성에 미치는 배지응고제는 0.6% Gelrite첨가배지에서 9.0%로 가장 높았다. 6. 기관분화를 위한 배지내 ABA와 $AgNO_3$의 첨가는 캘러스의 갈변을 억제하였으며, 5mg/L ABA첨가배지에서 뿌리분화가 이루어졌다.

• 열처리공학회지
• /
• 제18권3호
• /
• pp.172-176
• /
• 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.

• 한국전기전자재료학회논문지
• /
• 제28권2호
• /
• pp.85-91
• /
• 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
• /
• 제3권2호
• /
• pp.99-114
• /
• 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.