• 제목/요약/키워드: powers

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Oracle Software Powers The Internet

  • 안병문
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2000년도 제27회 춘계학술발표회 특강요약집 산업체발표 : E-Commerce
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    • pp.131-146
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    • 2000
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탄소섬유 물리적 특성 향상을 위한 스퍼터링 탄소박막의 특성에 대한 연구 (Characteristics of Sputtering Carbon Films for the Improvement of Physical Properties in Carbon Fiber)

  • 박철민;박용섭;김재문
    • 한국전기전자재료학회논문지
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    • 제28권11호
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    • pp.694-697
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    • 2015
  • We investigated the characterizations of carbon films fabricated by dual magnetron sputtering under various RF powers for the improvement of physical properties in carbon fiber (CF). All sputtered carbon films exhibited amorphous structure, regardless of RF powers, resulting in uniform and smooth surfaces. The hardness and elastic modulus are increased with the increase of RF power, and the adhesion and friction properties of carbon films were improved with the increase of RF power. In the results, The increase of RF power in the sputtering method improved tribological properties of the carbon films, and these attributes can be expected to improve the physical properties of the carbon fiber reinforcement plastics.

Multiple-Load Induction Cooking Application with Three-Leg Inverter Configuration

  • Sharath Kumar, P.;Vishwanathan, N.;Murthy, Bhagwan K.
    • Journal of Power Electronics
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    • 제15권5호
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    • pp.1392-1401
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    • 2015
  • Inverter configurations for multiple-load induction cooking applications need development. Inverter configurations for induction cooking applications are used in home appliances based on single coil inverters. For multiple-load configurations, multiple coils are used. They require proper inverters, which provide independent control for each load and have fewer components. This paper presents a three-leg inverter configuration for three load induction cooking applications. Each induction coil powers one induction cooking load. This configuration operates with constant switching frequency and powers individual loads. The output power of the required load is controlled with a phase-shift control technique. This configuration is simulated and experimentally tested with three induction loads. The simulation and experimental results are in good agreement. This configuration can be extended to more loads.

Definition of Power Quality Factors at The Point of Common Coupling in Single-Phase Systems and Three-Phase Systems

  • Kim Hyosung;Blaabjerg Frede;Bak-Jensen Birgitte
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.489-496
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    • 2001
  • This paper proposes an unified definition of powers for various circuit conditions such as balanced/unbalanced, sinusoidal/non-sinusoidal, and linear/nonlinear, for single-phase systems and three-phase systems. Conventional reactive power is more classified into an interactive power and a scattering power. These powers are defined both in the time domain and the frequency domain consistently, and agree well with the conservation law. Several important power quality factors are defined to measure and evaluate the power quality for the various circuits in the single-phase and three-phase systems. Simulation results show the power quality factors can evaluate and classify the various circuit conditions clearly.

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신경회로적인 전력조류 계산법에 대한 연구 (Load Flow Calculation by Neural Networks)

  • 김재주;박영문
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 하계학술대회 논문집
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    • pp.329-332
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    • 1991
  • This paper presents an algorithm to reduce the time to solve Power Equations using a Neural Net. The Neural Net is trained with samples obtained through the conventional AC Load Flow. With these samples, the Neural Net is constructed and has the function of a linear interpolation network. Given arbitrary load level, this Neural Net generates voltage magnitudes and angles which are linear interpolation of real and reactive powers. Obtained voltage magnitudes and angles are substituted to Power Equations, Real and reactive powers are found. Thus, a new sample is generated. This new experience modifies weight matrix. Continuing to modify the weight matrix, the correct solution is achieved. comparing this method with AC Load flow, this method is faster. If we consider parallel processing, this method is far faster than conventional ones.

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Fuzzy PSO Congestion Management using Sensitivity-Based Optimal Active Power Rescheduling of Generators

  • Venkaiah, Ch;Vinod Kumar, D M
    • Journal of Electrical Engineering and Technology
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    • 제6권1호
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    • pp.32-41
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    • 2011
  • This paper presents a new method of Fuzzy Particle Swarm Optimization (FPSO)-based Congestion Management (CM) by optimal rescheduling of active powers of generators. In the proposed method, generators are selected based on their sensitivity to the congested line for efficient utilization. The task of optimally rescheduling the active powers of the participating generators to reduce congestion in the transmission line is attempted by FPSO, Fitness Distance Ratio PSO (FDR-PSO), and conventional PSO. The FPSO and FDR-PSO algorithms are tested on the IEEE 30-bus and Practical Indian 75-bus systems, after which the results are compared with conventional PSO to determine the effectiveness of CM. Compared with FDR-PSO and PSO, FPSO can better perform the optimal rescheduling of generators to relieve congestion in the transmission line.

반도체 광 증폭기내에서의 4광파 혼합을 이용한 2.5Gb/s 광신호의 전광 파장변환 (All-optical wavelength conversion of 2.5 Gb/s optical signals by four-wave mixing in a semiconductor optical amplifier)

  • 방준학;서완석;이성은
    • 전자공학회논문지D
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    • 제35D권8호
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    • pp.69-75
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    • 1998
  • We demonstrate wavelength conversion of 2.5Gb/s optical signals by four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). We investigate the effect of input pump and signal powers on the coversion efficiency, optical signal-to-noise ratio (OSNR) and extinction ratio to be a measure of performance in a wavelength converter. As a result, we show that the maximum bit error rate (BER) performance can be obtained by co promising among high-vonversion efficiency (minimum Pprobe), high-OSNR (maximum Pprobe) and low-cross-gain saturation effects (Pprobe kept at least 6dB weaker than Ppump). In our experiment, we obtain optimum performance at +3 dBm pump power and -6dBm signal power. The power penalty incurred in the wavelength conversion can be minimized by careful selection of the input pump and signal powers. We show that about 0.5dB power penalty for 3.2nm wavelength coversion at 10-10 BER is achievable.

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