• 제목/요약/키워드: single point

검색결과 2,802건 처리시간 0.04초

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

  • 정맹식
    • 한국안광학회지
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    • 제4권2호
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    • pp.165-169
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    • 1999
  • 시료의 한 부분에 순간적으로 가열하여 시료의 특정 부분의 온도변화를 조사함으로써 시료의 열 확산도를 측정하였다. $Pb_5Ge_3O_{11}$ 단결정의 환산 열 확산도는 trigonal 구조인 $30^{\circ}C$에서는 $0.0117cm^2/^{\circ}C$, curie point 근방인 $178^{\circ}C$에서는 $0.0105cm^2/^{\circ}C$이며 hexagonal 구조인 $180^{\circ}C$에서는 0.0112cm로 각각 나타났다. 이는 $Pb_5Ge_3O_{11}$ 단결정을 같은 열량으로 가열하였을 때, 실온에서 curie 온도쪽으로 갈 때 가열 효과가 적었으며 curie point에서 최소가 되었다가 curie 온도 이상에서는 갑자기 증가하여 일정하게 되었다. 따라서 $Pb_5Ge_3O_{11}$ 단결정의 상전이 용도가 1m 근방임을 확인하였다.

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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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    • 제27권9호
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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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    • 제13권5호
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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.

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

  • 유상하;홍광준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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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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단일 양자점으로부터 발생한 발광세기 변화에 대한 베이지안 다중 변화점 추정 (Bayesian Multiple Change-Point Estimation for Single Quantum Dot Luminescence Intensity Data)

  • 김재희;김학준
    • 응용통계연구
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    • 제26권4호
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    • pp.569-579
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    • 2013
  • 단일 분자에서 발생한 발광의 세기 변화를 분석하는 문제는 단분자 분광학에서 반드시 필요하다. 본 연구에서는 카드뮴셀레나이드/황화아연의 중심-껍질 구조를 갖는 양자점에 대한 단분자 분광학 데이터에 대해 Poisson count data로서 베이지안 접근으로 모수에 대한 공액 감마분포와 변화점 개수에 대한 절단포아송 분포로 사전분포를 주고 다중변화점을 추정하였다.

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

  • 양병렬;권병일;박승찬
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제51권2호
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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
    • 한국정보기술학회 영문논문지
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    • 제9권1호
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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.

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

  • 김만식;김실근;홍정표;홍순일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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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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최대전력점 추적에 의한 태양광 인버터 시스템 구현 (Implemented of Photovoltaic Inverter System by a Maximum Power Point Tracking)

  • 송인선;김실근;정승환;홍순일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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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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Pipeline 방식 256-point FFT Processor의 설계 (Design of a 256-point FFT Processor)

  • 서정훈;송인채
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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    • pp.301-304
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    • 2000
  • In this paper, we designed a 256-point FFT processor using VHDL. We adopted Radix-2$^2$SDC(Single-path Delay Commutator) architectures to reduce the number of complex multipliers. We confirmed the operation of the design through simulation using Altera MAX+PLUS II.

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