• Title/Summary/Keyword: Circuit arrangement

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A Dynamic Programming Approach to Feeder Arrangement Optimization for Multihead-Gantry Chip Mounter (동적계획법에 의한 멀티헤드 겐트리형 칩마운터의 피더배치 최적화)

  • 박태형
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.6
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    • pp.514-523
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    • 2002
  • Feeder arrangement is an important element of process planning for printed circuit board assembly systems. This paper newly proposes a feeder arrangement method for multihead-gantry chip mounters. The multihead-gantry chip mounters are very popular in printed circuit board assembly system, but the research has been mainly focused on single-head-gantry chip mounters. We present an integer programming formulation for optimization problem of multihead-gantry chip mounters, and propose a heuristic method to solve the large NP-complete problem in reasonable time. Dynamic programming method is then applied to feeder arrangement optimization to reduce the overall assembly time. Comparative simulation results are finally presented to verify the usefulness of the proposed method.

Reduction of Electromagnetic Force in AC Distributed Winding of Fault Current Limiter under Short-Circuit Condition

  • Ghabeli, Asef;Yazdani-Asrami, Mohammad;Doroudi, Aref;Gholamian, S. Asghar
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.400-404
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    • 2015
  • Various kinds of winding arrangements can be used to enable fault current limiters (FCL) to tolerate higher forces without resulting in a substantial increase in construction and fabrication costs. In this paper, a distributed winding arrangement is investigated in terms of its effects on the short-circuit forces in a three-phase FCL. The force magnitudes of the AC supplied windings are calculated by employing a finite element-based model in the time stepping procedure. The leakage flux and radial and axial force magnitudes obtained from the simulation are compared to those obtained from a conventional winding arrangement. The comparison shows that the distributed winding arrangement significantly reduces the radial and, especially, the axial force magnitudes.

Effect of Phase Arrangement on Magnetic Field of Overhead Transmission Lines (송전선로의 상배열이 자계 크기에 미치는 영향)

  • Kim, Sang-Beom;Lee, Dong-Il;Shin, Koo-Yong;Kim, Jeong-Soo
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1678-1680
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    • 1998
  • The purpose of this study is to obtain optimum arrangement of phase conductors in minimizing magnetic field from overhead transmission lines. Data of the transmission lines rated 345 kV of the KEPCO(Korea Electric Power Company)'s system were used. For a three phase-double circuit transmission line, low-reactance arrangement is optimum in minimizing magnetic fields. For a three phase-four circuit, optimum phase arrangement is a-b-c-b-a-c(lower two circuits, clockwise)/b-c-a-c-a-b(upper two circuits, clockwise).

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Magnetic Field Analysis in Accordance with Line Configuration Type in Underground Transmission Systems (지중송전계통에서 선로의 구성방식에 따른 자계 해석)

  • Lee, Jae-Myeong;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.12
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    • pp.1673-1678
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    • 2015
  • This paper describes magnetic field on power cable in underground transmission systems. Based on specification which is being used in domestic power utility, magnetic field was analyzed in accordance with line arrangement, line burial depth and phase spacing. Magnetic field magnitude and its trend were understood in each circuit type such as double circuits, triple circuits and quadruple circuits of underground transmission systems. In addition, magnetic field was analyzed according to phase arrangement changing in each circuit. Finally, the proper phase arrangement configuration type was suggested by the evaluation of analysis result. Magnetic field was calculated by using Biot-Savart's law. According to the evaluated magnetic fields based on phase layout configuration in each circuit, it figured out that each of magnetic fields was different. As a result, this paper proposes a proper phase layout configuration for generating minimum magnetic field. It is evaluated that the phase layout configuration in each circuit proposed in this paper can be used at actual underground transmission systems.

An Experimental Study on the Noise and Vibration reduction of Projector Driving Board (Projector 회로 소음 및 진동 저감의 실험적 연구)

  • Choi, Youngsoo;Soug, Keunyoung;Yi, Jougkwon;Oh, Houglyeol;Lee, Seunggyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.135-140
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    • 2013
  • This paper deals with noise reduction on a light source driving board in a projector. We analyze causes of noise/vibration in the circuit with the present increasing use of LD and LED driving boards. The main source of noise is the MLCC in the driving board. Our aim is to investigate how the mechanical arrangement of the circuit elements affects noise reduction. The result of our experiment shows that noise can be reduced by symmetrical arrangement and slots in PCB. This result is expected to facilitate a variety of applications for manufactures without a need to change circuit elements.

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Countermeasures for reducing the zero sequence circulating current in parallel untranposed 154kV four-circuit systems. (154kV 송전계통 비연가 4회선 병행선로에서의 영상순환전류 감소대책)

  • Yoon, Yong-Beum;Choo, Jin-Boo;Baek, Young-Ki
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.913-915
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    • 1996
  • This paper proposes the proper phase arrangement of transmission lines for reducing the zero sequence circulating current. It is a well-known fact that the zero sequence circulating currents are principally caused by the untranposed lines and numerical estimation method already has been established. In this paper, the circuit analysis for calculating the zero sequence circulating currents was performed on the existing 154kV four-circuit systems of KEPCO and the proper phase arrangement was determined.

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Characteristic of air-side sensible heat transfer and pressure drop on the corrugate fin tube heat exchangers (Corrugate 휜-관 현열 열교환기의 구조에 따른 공기측 열전달 및 압력손실 특성)

  • Ryu, Joon-Il;Jeon, Chang-Duk;Lee, Jin-Ho;Nam, Leem-Woo
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.216-221
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    • 2007
  • An experiment was carried out to investigate the effect of a coolant circuit arrangement on the heat transfer and air pressure drop of a fin-tube sensible heat exchanger with the corrugated fin surface. The air inlet temperature was set to $23^{\circ}C$,the relative humidity to 50% and the air inlet flow rate to 20, 22, $25m^3/min$, respectively. while the coolant temperature was set to $7^{\circ}C$, and the coolant mass flow rate to 10, 16, 22kg/min, respectively. Experiment showed that the exchanger having a diameter of 12.7mm with parallel circuit does better performance in sensible heat transfer and air pressure drop than those three of diameter of 12.7mm with a series circuit and that with diameter of 15.88mm with a parallel circuit.

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EDGE PROPERTIES OF THE 4-VALENT MULTI 3-GON GRAPHS

  • Jeong, Dal-Young
    • Communications of the Korean Mathematical Society
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    • v.19 no.3
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    • pp.577-584
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    • 2004
  • In a 4-valent multi 3-gon graph, every cut-through curve forms a simple closed circuit. Hence it is a weak arrangement of simple curves that is defined by Branko Grunbaum. In this paper, we study the edge properties of the 4-valent multi 3-gon graphs from the point of view of arrangement, and we show that they are 3 colorable.

Effect of Conductor's Arrangement and Current Direction on AC Loss Characteristics of a Fault Current Limiting Coil (도체의 배열 및 전류방향이 코일형 한류소자의 교류손실 특성에 미치는 영향)

  • Ma Y. H.;Ryu Kyung-Woo;Park K. B.;Oh Il-Sung
    • Progress in Superconductivity and Cryogenics
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    • v.7 no.3
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    • pp.17-20
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    • 2005
  • AC loss of a high $T_c$ superconducting conductor has a strong influence on the economic viability of a superconducting fault current limiter, which offers an attractive means to limit short circuit current in the power systems. Therefore, several samples of the fault current limiting coils have been fabricated and the effect of conductor's arrangement and current direction on AC loss characteristics investigated experimentally The test result shows that the AC losses measured in the fault current limiting coils depend significantly on the conductor's arrangement. Futhermore, they are also considerably influenced by the conductor's current direction. The AC loss measured in the face-to-face arrangement is smallest among the fault current limiting coil samples.

The Characteristics of a Hydrogenated Amorphous Silicon Semitransparent Solar Cell When Applying n/i Buffer Layers

  • Lee, Da Jung;Yun, Sun Jin;Lee, Seong Hyun;Lim, Jung Wook
    • ETRI Journal
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    • v.35 no.4
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    • pp.730-733
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    • 2013
  • In this work, buffer layers with various conditions are inserted at an n/i interface in hydrogenated amorphous silicon semitransparent solar cells. It is observed that the performance of a solar cell strongly depends on the arrangement and thickness of the buffer layer. When arranging buffer layers with various bandgaps in ascending order from the intrinsic layer to the n layer, a relatively high open circuit voltage and short circuit current are observed. In addition, the fill factors are improved, owing to an enhanced shunt resistance under every instance of the introduced n/i buffer layers. Among the various conditions during the arrangement of the buffer layers, a reverse V shape of the energy bandgap is found to be the most effective for high efficiency, which also exhibits intermediate transmittance among all samples. This is an inspiring result, enabling an independent control of the conversion efficiency and transmittance.