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The Phase Transition of Pb5Ge3O11 Single Crystal by the Thermal Conduction Measurement (열전도 측정에 의한 Pb5Ge3O11 단결정의 상전이)

  • Joung, Maeng-Sig
    • Journal of Korean Ophthalmic Optics Society
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    • v.4 no.2
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    • pp.165-169
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    • 1999
  • The thermal diffusivity of lead germanate single crystal was measured from room temperture up to the $200^{\circ}C$ by heating method. The thermal diffusivities were measured as k=0.0117, 0.0105, and $0.0112cm^2/^{\circ}C$ at $30^{\circ}C$, $177^{\circ}C$, and $180^{\circ}C$, respectively. It is identified that the heat capacity of the lead germanate single crystal is maximum at $177^{\circ}C$, and this point is phase transition temperature of $Pb_5Ge_3O_{11}$ single crystal.

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Single-Strand Conformation Polymorphism Analysis by Microchip Electrophoresis for the Rapid Detection of Point Mutation in Human Obesity Gene

  • Kang, Seong-Ho;Jang, Soo-Young;Park, Sang-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.27 no.9
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    • pp.1346-1352
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    • 2006
  • We describe an effective method of microchip electrophoresis (ME) based on single strand conformation poly-morphism (SSCP) analysis to rapidly detect the point mutation, Leu72Met, in a human obesity gene. The 207-bp dsDNA in the Leu72Met region, an estimate of the child obesity DNA mutant, was amplified by polymerase chain reaction (PCR) and submitted to a conventional glass microchip analysis with a sieving matrix of 1.75% poly(vinylpyrrolidone) (Mr 1 300 000), 1.0% poly(ethyleneoxide) (Mr 600 000) and 5.0% w/w glycerol. When combined with base stacking (BS) with hydroxide ions, the SSCP-ME provided rapid analysis as well as sensitive detection. The detection sensitivity was effectively enhanced in the OH- concentration range of 0.01-0.025 M NaOH. The sensitivity and speed of this ME-based SSCP methodology for the rapid detection of Leu72Met point mutations makes this an attractive method for diagnosing childhood obesity in a clinical diagnostic laboratory.

Fast Voltage-Balancing Scheme for a Carrier-Based Modulation in Three-Phase and Single-Phase NPC Three-Level Inverters

  • Chen, Xi;Huang, Shenghua;Jiang, Dong;Li, Bingzhang
    • Journal of Electrical Engineering and Technology
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    • v.13 no.5
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    • pp.1986-1995
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    • 2018
  • In this paper, a novel neutral-point voltage balancing scheme for NPC three-level inverters using carrier-based sinusoidal pulse width modulation (SPWM) method is developed. The new modulation approach, based on the obtained expressions of zero sequence voltage in all six sectors, can significantly suppress the low-frequency voltage oscillation in the neutral point at high modulation index and achieve a fast voltage-balancing dynamic performance. The implementation of the proposed method is very simple. Another attractive feature is that the scheme can stably control any voltage difference between the two dc-link capacitors within a certain range without using any extra hardware. Furthermore, the presented scheme is also applicable to the single-phase NPC three-level inverter. It can maintain the neutral-point voltage balance at full modulation index and improve the voltage-balancing dynamic performance of the single-phase NPC three-level inverter. The performance of the proposed strategy and its benefits over other previous techniques are verified experimentally.

Study point defect and growth for $CuInSe_2$ single crystal thin film by hot wall epitaxy (Hot Wall Epitaxy (HWE) 법에 의한 $CuInSe_2$ 단결정 박막 성장과 점결함 연구)

  • Yu, Sang-Ha;Hong, Gwang-Jun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.152-153
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    • 2007
  • $CuInSe_2$ single crystal thin film was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. After the as-grown $CuInSe_2$ single crystal thin films was annealed in Cu-, Se-, and In-atmospheres, the origin of point defects of $CuInSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Cu}$, $V_{Se}$, $Cu_{lnt}$, and $Se_{lnt}$ obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Cu-atmosphere converted $CuInSe_2$ single crystal thin films to an optical n-type. Also, we confirmed that In in $CuInSe_2$/GaAs did not form the native defects because In in $CuInSe_2$ single crystal thin films existed in the form of stable bonds.

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Bayesian Multiple Change-Point Estimation for Single Quantum Dot Luminescence Intensity Data (단일 양자점으로부터 발생한 발광세기 변화에 대한 베이지안 다중 변화점 추정)

  • Kima, Jaehee;Kimb, Hahkjoon
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.569-579
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    • 2013
  • In the field of single-molecule spectroscopy, it is essential to analyze luminescence Intensity changes that result from a single molecule. With the CdSe/ZnS core-shell structured quantum dot photon emission data Bayesian multiple change-point estimation is done with the gamma prior for Poisson parameters and truncated Poisson distribution for the number of change-points.

Design of Air Gap for Reducing Torque Ripple in a Single-Phase BLDC Motor (단상 BLDC 전동기의 토오크 리플 저감을 위한 공극 설계)

  • Yang, Byeong-Ryeol;Gwon, Byeong-Il;Park, Seung-Chan
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.2
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    • pp.49-54
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    • 2002
  • Most single-Phase brushless DC (BLDC) motors have unequal air gap to eliminate the dead-point where the developed torque value is zero. However this partial increase of the air gap deteriorates the motor characteristics in cogging torque. Thus in this paper a new topology of unequal air gap is proposed to solve this problem. The topology is to use some pairs of equal or unequal air gaps. As a result, it is proved by the finite element analysis and experimental results that the single-Phase BLDC motor with the proposed air gap topology is very effective in reducing the cogging torque.

Performance Comparison of Single-Carrier and Multi-Carrier Systems in a Terahertz Wireless Communication Environment

  • Asiedu, Derek Kwaku Pobi;Ahiadormey, Roger Kwao;Shin, Suho;Lee, Kyoung-Jae
    • Journal of Advanced Information Technology and Convergence
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    • v.9 no.1
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    • pp.11-24
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    • 2019
  • This paper investigates the performance comparison of a Terahertz (THz) communications for a single-carrier and a multi-carrier single antenna point-to-point communication system. The multi-carrier system and single carrier system consider the orthogonal frequency division multiplexing (OFDM) and the minimum mean square error linear equalizer (MMSE-LE), respectively. We compare the frame-error-rate (FER) and throughput performance of both the systems for a THz communication environment with the carrier frequency of 300GHz and the tapped delay line (TDL) channel models described in 3GPP. It is observed from the simulation results that the OFDM systems outperform the MMSE-LE for various configurations.

Maximum Power Point Tracking Photovoltaic Invert (최대전력 추적 태양광 인버터 시스템)

  • Kim, Man-Sig;Kim, Sil-Keun;Hong, Jung-Pyo;Hong, Soon-Ill
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.1191-1192
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    • 2006
  • This paper propose method of maximum power point tracking using boost converter for a connected single phase inverter. The maximum power point tracking control is based on generated circuit control MOSFET switch of two boost converter and single phase inverter uses predicted current control to control four IGBT's switch in full bridge. The predicted current control provide current with sinusoidal wave shape and inphase with voltage.

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Implemented of Photovoltaic Inverter System by a Maximum Power Point Tracking (최대전력점 추적에 의한 태양광 인버터 시스템 구현)

  • Song, In-Sun;Kim, Sil-Keun;Jung, Seoung-Hwan;Hong, Soon-Ill
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.224-225
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    • 2007
  • In this paper proposed method of maximum power point tracking using boost converter for a connected single phase inverter. The maximum power point tracking control is based on generated circuit control MOSFET switch of two boost converter and single phase inverter uses predicted current control to control four IGBT's switch in full bridge. The predicted current control provide current with sinusoidal wave shape and inphase with voltage.

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