• Title/Summary/Keyword: Common pole

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Effective Room Equalization Using Warped Common Acoustical Pole and Zero (Warped Common Acoustical Pole and Zero 방법을 이용한 효율적인 공간 등화)

  • Lee, Jun-Ho;Park, Young-Cheol;Youn, Dae-Hee;Lee, Seok-Pil
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.1
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    • pp.51-60
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    • 2009
  • This paper presents a new method of designing room equalization filters using a warped common acoustical pole and zero (WCAPZ) modeling. The proposed method is capable of significantly reducing the order of the equalization filters without sacrificing the filter performance, especially, at low frequencies. Thus, the associated input-output delay is much smaller than the conventional block transform method while its computational complexity is comparable to it. The computational complexity also is still comparable to the conventional room equalization method, since the filter is implemented in the linear frequency domain after the pole-zero dewarping. Simulation results confirm that the use of the proposed algorithm significantly improves the room equalization over a range of low frequencies.

A Study of Performance Test of High Speed Solenoid for Fuel Injector in Diesel Engine (디젤기관의 분사밸브를 위한 고속 솔레노이드의 성능에 관한 연구)

  • Cho, K.H.;Rha, J.H.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.5 no.3
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    • pp.11-16
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    • 2001
  • In the DI diesel engine of passenger cars, common rail injection system have been used to improve the engine performance and reduce the exhaust emission by controlling injection timing, injection pattern, and injection duration. In case that common rail injection system is applied to high speed DI diesel engine, it is necessary to have high response and good repetition characteristics. These characteristics of injector depend on the characteristics of solenoid. Thus, to apply the common rail injection system in the high speed diesel engine, we had designed and made a multi-pole solenoid, and carried out repetition, response test to compare the multi-pole solenoid with the gasoline Injector solenoid. The result shows that repetition and response characteristics of multi-pole solenoid have better characteristics than the gasoline injector solenoid.

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A Study of Concentric-Neutral Line Voltage Increase Related by Pole and Cable Joint When Lightening Overvoltage Injected in Combined Distribution Line (혼합 배전선로에 직격낙뢰시 전주와 케이블직선접속재가 케이블 동심중성선 전위상승에 미치는 영향)

  • Jeon, Yong-Joo;Jeon, Myung-Su
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.6
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    • pp.702-707
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    • 2018
  • In case of Lighting occurs in Domestic combined distribution line, normally the voltage for the neutral line increase dramatically. General connection for underground cable is bundled common earth type so the lightning over voltage increase at the concentric-neutral line is not big enough to give impact on cable sheath. But in case of Non bundled common earth type it is necessary to analyze the phenomena on cable sheath caused by lightening overvoltage. Especially pole and cable joint are the core factor to consider. In this paper concrete pole and cable joint were evaluated in case of Non bundled common earth type combined distribution Line. EMTP simulation model has been designed and several case study were made. Also several experimental test were made to verify the simulation result.

Common-mode Voltage Reduction of Three Level Four Leg PWM Converter (3레벨 4레그 PWM 컨버터의 커먼 모드 전압 저감)

  • Chee, Seung-Jun;Ko, Sanggi;Kim, Hyeon-Sik;Sul, Seung-Ki
    • The Transactions of the Korean Institute of Power Electronics
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    • v.19 no.6
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    • pp.488-493
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    • 2014
  • This paper presents a carrier-based pulse-width modulation(PWM) method for reducing the common-mode voltage of a three-level four-leg converter. The idea of the proposed PWM method is intuitive and easy to be implemented in digital signal processor-based converter control systems. On the basis of the analysis of space-vector PWM(SVPWM) and sinusoidal PWM(SPWM) switching patterns, the fourth leg pole voltage of the three-phase converter called "f leg pole voltage" is manipulated to reduce the common-mode voltage. To synthesize f leg pole voltage for the suppression of the common-mode voltage, positive and negative pole voltage references of f leg are calculated. An offset voltage is also deduced to prevent the distortion of a, b, and c phase voltages. The feasibility of the proposed PWM method is verified by simulation and experimental results. The common-mode voltage of the proposed PWM method in peak-to-peak value is 33% in comparison with that of the conventional SVPWM method. The transition number of the common-mode voltage is also reduced to 25%.

Development of The H Type Steel Pole for 154kV Transmission Lines (154kV 송전선로용 H형 Steel Pole 개발)

  • Byun, Gang;Min, Byeong-Wook;Shin, Tai-Woo;Choi, Jin-Sung;Jiang, Moon-Myong;Song, Teak-Sang
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.433-435
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    • 2003
  • As the nation's standard of living rises lately, the common interest in the environmental issue is raised and the environmental design of a transmission line is needed. When the environmental design is needed, KEPCO used a steel pole instead of a rectangular tower. A steel pole has many advantages such as simplification of a tower and less damage to the forest according to less demand of site. But the weak withstand weight of a mono type steel pole is a problem. This paper introduces an H type steel pole which improves its withstand weight, reduces a diameter of a pole from 2.6m to 1.3m and decreases joining points according to the increase of unit length of a pole from 6m to 9m.

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Analysis of Two-phase E-core Switched Reluctance Machines Using Magnetic Equivalent Circuit Technique (자기등가회로 기법을 사용한 2상 E-core SRM의 해석에 관한 연구)

  • Lee, Chee-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.11
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    • pp.1986-1989
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    • 2010
  • The modification of magnetic structures for an E-core switched reluctance machine (SRM) comprising two segmented stator cores or a monolithic stator core is presented for ease of assembly, good manufacturability, mechanical robustness, and electromagnetic performance improvement. The E-core stator has four small poles with phase windings and two or four large poles (hereafter referred to as common poles), in between. The common poles are shared by both phases for positive torque generation during the entire operation. The E-core SRMs are compared to a conventional two-phase SRM. The comparison includes cost savings, torque, copper and core losses, and efficiency in order to validate the distinct features of the E-core SRMs. Magnetic equivalent circuit (MEC) technique is employed for proving the benefits of the E-core common-pole structure.

Superior Pole Sleeve Fracture of the Patella in Children - A Case Report - (소아에서 발생한 슬개골 상단부 소매형 골절 - 증례 보고 -)

  • Kim, Ki-Choul;Ahn, Gil-Yeong;Nam, Il-Hyun;Moon, Gi-Hyuk;Lee, Yeong-Hyun;Lee, Jae-Hoon
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.8 no.2
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    • pp.121-124
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    • 2009
  • Patellar fractures in children represent less than 2% of all patellar fractures including adults, and occur about 1% of all pediatric fractures. Because of property of the growing patella, osteochondral or avulsion fractures are more common in children and the most common type of patella fracture in children is sleeve fracture. Avulsion or sleeve fractures of the patella in children can occur at the superior or inferior pole of the patella. Most reported cases of sleeve fracture are involving the inferior patellar pole, but involving the superior patellar pole is very rare. We experienced a case of sleeve fracture occurred at the superior pole of the patella in a sixteen-year-old boy and report this case with literature review.

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Design of a Pole-Balancing Controller Using Neural Networks (신경회로망을 이용한 역추균형 재어기 설계)

  • 김유석;이장규
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.2
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    • pp.217-223
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    • 1991
  • Most common applications of neural networks to control problems are the automatic motor controls using the artificial perceptual function. These control mechanisms are similar to those of the intelligent and pattern recognition control of an adaptive method frequently performed by the animate nature. In this paper, the pole-balancing problem is selected as the control object and an actual cart-pole controller is implemented by a computer interfacing and demonstrated as motor control using the reinforcement learning rule. In the experiment, given a change of the main parameters of cart-pole dynamics, a comparison is made between the LQR scheme and neural network method. The neural network method exhibits a more effecftive control action in a real situation having a large uncertainty than the LQR scheme.

Design and Implementation of Crosstalk Canceller Using Warped Common Acoustical Poles (주파수 워핑된 공통 극점을 이용한 음향 간섭제거기의 설계 및 구현)

  • Jeong, Jae-Woong;Park, Young-Cheol;Youn, Dae-Hee;Lee, Seok-Pil
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.5
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    • pp.339-346
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    • 2010
  • For the implementation of the crosstalk canceller, the filters with large length are needed, which is because that the length of the filters greatly depends on the length of the head-related impulse responses. In order to reduce the length of the crosstalk cancellation filters, many methods such as frequency warping, common acoustical pole and zero (CAPZ) modeling have been researched. In this paper, we propose a new method combining these two methods. To accomplish this, we design the filters using the CAPZ modeling on the warped domain, and then, we implement the filters using the poles and zeros de-warped to the linear domain. The proposed method provides improved channel separation performance through the frequency warping and significant reduction of the complexity through the CAPZ modeling. These are confirmed through various computer simulations.

Fabrication and Measurement of Tunable Millimeter-wave Filters (주파수 가변형 밀리미터파 필터의 제작 및 측정)

  • Park, Jae-Hyoung;Kim, Hong-Teuk;Kwon, Young-Woo;Kim, Yong-Kweon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.11
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    • pp.627-634
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    • 2000
  • In this paper, new micromachined tunble bandpass filters for multi-band millimeter-wave telecommunication systems are proposed. Two types of mm-wave tunable filters are fabricated using micromachning technology and the responses of the filters are measured. One is two-pole lumped elements filter and the other two-pole resonators filter. Frequency tunability of the filter is achieved by changing the gap between a common CPW ground plate and the movable cantilever beam connected to the transmission line with the controllable renge of 2.5${\mu}m$. The deflection of cantilever beam is measured with the applied DC voltage. With the applied bias voltage from 0 to 50 V, the fabricated filters show 0.6 GHz(2.3%) at 26.6 GHz, and 0.8 GHz(2.5%) at 32 GHz center frequency shift for the lumped elements and resonators filter, respectively. The life time of the fabricated gold cantilever structure are tested.

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