• Journal of the Korean Magnetics Society
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• v.26 no.1
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• pp.31-37
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• 2016

This study considered the reduction of the detent force of a permanent magnet linear synchronous generator (PMLSG). The PMLSG has a relatively large magnetic air gap. Thus, a slotted type of stator structure is generally employed. Furthermore, the detent force, which is caused by energy imbalances owing to the interaction between tooth-slot structures and the permanent magnets (PMs), must be minimized for start-up operation. Therefore, in this paper, the methods of auxiliary teeth and a notch in the teeth are applied to reduce the detent force.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1332-1333
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• 2011

본 논문에선 해수압 진동을 이용한 파력발전 장치에 대해 소개한다. 본 파력발전장치는 5~10m의 수심에 설치되며 파고의 변화에 따른 수압의 진동을 이용해 전기를 생산한다. 수압의 진동은 파력발전 장치 내의 피스톤을 진동시키고 이 피스톤에 연결된 선형발전기(linear permanent magnet generator)를 진동시켜 전기를 생산한다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.82-91
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• 2002

방파제에 대한 신뢰성 설계 방법은 유럽과 일본을 중심으로1980년대 중반 이후로 발전되어 왔다. 유럽에서는 van der Meer(1988a)가 방파제 피복재의 설계에 확률론적인 방법을 도입하였고, Burcharth(1991)는 사석방파제에 대하여 부분안전계수(partial safety factor)를 이용한 신뢰성 설계 방법을 제시하였다 최근 Burcharth and Sørensen(1999)은 PIANC (Permanent International Association of Navigation Congress) Working Groups의 결과를 요약하여 사석방파제와 직립방파제에 대한 부분안전계수들을 확립하였다. (중략)

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.79-81
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• 2009

튜블러 선형 동기발전기는 간단하고 안정적인 구조이며, 구조적으로 수직력이 발생하지 않는다. 본 논문에서는 파력발전에 튜블러 선형 동기발전기를 소개한다. 또한 flat type과 특성비교를 통하여 튜블러 발전기가 파력발전에 적합함을 증명하였다.

• Journal of the Korean Society of Fashion and Beauty
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• v.6 no.2
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• pp.73-79
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• 2008

To study of the rate of damage and morphological change when apply perm and dye according to kinds of curly hair, measured the thickness of hair and divided the samples into groups. Measured the chromaticity and thickness according to kinds of curly hair and chemical treatment with Spectrum colormeter and Micrometer. Measured the tensile strength of hair then calculated the damage rate. After tensile test, took photographs of the section and surface with the electron microscope.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.1
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• pp.13-17
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• 2016

EMC (Electro Magnetic Compatibility) of the electrical railway must be ensured for safety of passenger. Maglev trains has not friction between the wheels and the rails because levitation by an permanent magnets, electromagnets and superconducting magnets etc. So, it is advantageous to maintain a high speed without noise and vibrations. In this paper, we investigated that the magnetic field of the before and after installation electromagnetic waves absorber in order to analyze the effects of electromagnetic waves. The theoretical analysis of the electromagnetic wave absorber was simulated using finite element method. The magnetic field properties of electromagnetic waves absorber were measured by EMI (Electro Magnetic Interference) test receiver.

• Journal of Power Electronics
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• v.9 no.2
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• pp.173-179
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• 2009

This paper proposes a new three-phase diode rectifier system with a sinusoidal input current at unity power factor and a regulated and isolated output voltage at low level. The inherent natural wave-shaping capability of the reduced kVA polyphase transformer together with an active current wave-shaping technique results in a significant reduction of input and output filter requirements associated with switching ripple and EMI. The operation principles are described along with a design example and a comparative evaluation. Experimental results on a 1.5kW prototype are provided to validate the proposed concept.

• Journal of Industrial Technology
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• v.27 no.A
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• pp.149-155
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• 2007

The counter emf(electromotive forces) of a permanent magnet multi-phase brushless motor is generally a non-sinusoidal wave or a non-ideal trapezoid. So, conventional modeling using a sinusoidal wave or an ideal trapezoid counter emf can result in errors. In order to reduce modeling errors for simulation and analysis the properties of a multi-phase brushless AC motor, this paper proposes a phase variable model that is a mixed modeling technique using both Finite Element Analysis(FEA) based circuits and motor voltage equations. The phase model parameters including the counter emf voltage waveform are obtained by using of FEA, and the mixed modeling technique based on circuits and equations is used to implement a simulation model for multi-phase brushless AC motors with any counter emf voltage waveforms. Adequacy of the proposed model is established from the simulation and experimental results for a seven-phase brushless motor.

• Geomechanics and Engineering
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• v.30 no.4
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• pp.353-362
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• 2022

The seismic failure-prone region in Istanbul has been examined in terms of the segmented pipelines. Although some researchers have suggested that this territory should be left as a green land, many people continue to live in this area. This region is about 9-10 km away from the North Anatolian Fault Line. This fault zone is an active right-lateral strike-slip fault line in Turkey and an earthquake with a magnitude of 7.0-7.5 is expected in the Marmara Sea. Therefore, superstructures and infrastructures are under both land sliding risks and seismic risks in this area. Because there are not any pipeline-fault line intersection points in the region, in this study, it has been focused on the behaviors of the segmented (sewage or stormwater) pipelines subject to earthquake-induced permanent ground deformation and seismic wave propagation. Based on the elastic beam theory some necessary analyses have been carried out and obtained results of this approximation have been examined.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.58-69
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• 1995

The present paper is devoted to constructing a numerical algorithm for solving un steady problems on generation, propagation and interaction of nonlinear waves at a surface of ideal fluid, within the framework of the potential-flow model. The numerical scheme is implicit. with non-linearity iteration at every step of time. the finite-difference method with boundary-fitted coordinates are presented in favor for validity and high efficiency of the numerical model developed. Among these arguments, there are the results of calculations of two test problems-on stretching of a liquid ellipse and on wave generation by lifting a portion of a bottom.