• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.53-56
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• 2007

Magnesium sheet used in electrical device due to mobility and EMF shielding characteristics. Magnesium case by press forming was advantageous compare with conventional die casting process, because of its thin gauge of wall and surface quality. But it need to makes the boss to fix inner part or assemble the case. CD stud welding was effective way for joining the boss to the thin gauge case of the electrical devices. In this study, we investigated the performances of the magnesium boss welder To measure the process parameters such as the force and the weld current, we design the monitoring system for CD stud welding. We test the characteristics of CD stud welding for AZ31 sheets at some variables. Finally we select the optimum welding range of magnesium sheets in CD stud welding process.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2228-2230
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• 2002

The research presented in this paper focuses on a method for the detection of High Impedance Fault(HIF). The method will use the Lifting and neural network system. HIF on the multi-grounded three-phase four-wires primary distribution power system cannot be detected effectively by existing over current sensing devices. These paper describes the application of lifting scheme to the various HIF data. These data were measured in actual 22.9kV distribution system. Wavelet transform analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate HIF from the normal status by a gradient descent method. The proposed method performed very well by proving the right state when it was applied staged fault data and normal load mimics HIF, such as arc-welder.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.793-799
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• 2004

In track a third weakness point is joint part, turnout part, curve part. One of them joint part of rail have been known to the most weak point by loosen of joint bar and fish bolt due to impulse and vibration by wheel contact at times. In addition happen to deformation and failure at end of rail, failure and miniature of ballast gravel. Finally impact between wheel and rail become origin cause of a welded rail, noise and vibration. riding condition deterioration, besides track failure. In the present domestic, Thermite and Gas pressure weldings have been used to continuous welded rail(CWR), however stiffness and confidence in quality is lower than Flash butt welding method. FRW have the excellent capacity, however have a shortcoming large scale of machine and power equipment. Therefore we will introduce Mobile Flash Butt Welder can weld in track.

• 전기의세계
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• 제21권4호
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• pp.27-38
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• 1972

This paper discusses the characteristics about the ignition of D.C. main discharge is a plasma jet generator, manufactured for trial as non-transferred type, when the electrical energy appropriate to the ignition is supplied to the gap between the electrodes by using advance discharge of attenuating high frequency voltage generated by a high frequency oscillator with mercury spark gap. These characteristics are under the influences of (a) the length of mercury gap in high frequency oscillator and the quantity of hydrogen flow supplied to it, (b) the condenser capacity of the high frequency oscillator circuit, (c) the length of plasma jet torch in D.C. main discharge circuit and the quantity of argon flow supplied to it, (d) the circuit constants of D.C. main discharge circuit. The results for these characteristics, obtained by this research, are considered to be helpful to the designs for the ignition of a plasma jet as well as the welding arc stabilizer by high frequency discharge and the high frequency arc welder.

• 한국기계가공학회지
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• 제11권6호
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• pp.158-163
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• 2012

This study investigates numerical analysis for robot welder fume flow and gantry structure. The solvers are STAR-CCM+ and ANSYS workbench used on flow and structural analysis. The results show that fume is diffused in factory when the welding fume is remove at dust collector. But dust collector intercepts the fume diffusion into workroom by removing most of welding fume. Structure analysis result shows that the reinforcement rod is evaluated to main the safety by supporting sufficient structure.

• 대한전기학회논문지:전력기술부문A
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• 제50권3호
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• pp.105-111
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• 2001

The research presented in this paper focuses on a method for the detection of High Impedance Fault(HIF). The method will use the wavelet transform and neural network system. HIF on the multi-grounded three-phase four-wires primary distribution power system cannot be detected effectively by existing over current sensing devices. These paper describes the application of discrete wavelet transform to the various HIF data. These data were measured in actual 22-9kV distribution system. Wavelet transform analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate HIF from the normal status by a gradient descent method. The proposed method performed very well by proving the right state when it was applied staged fault data and normal load mimics HIF, such as arc-welder.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.337-339
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• 2007

본 논문에서는 유한요소 해석 소프트웨어를 이용하여 연질금속을 접합할 수 있는 초음파 금속용접기용 트랜스듀서를 개발하였다. 개발된 트랜스듀서는 35kHz의 공진 주파수의 특성을 갖게 설계하였으며 트랜스듀서 플랜지의 종축변위가 최소가 되도록 설계하였다. 볼트체결형 트랜스듀서는 결속력에 따라 기계적 Q값이 변동되어 출력에 많은 영향을 준다. 따라서 특성 실험을 통하여 트랜스듀서에 대한 체결토크를 최적화하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2772-2774
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• 2003

The power source of inverter welder stable power of low voltage and high current. Because if shouldn't be, it is caused to spark between the parent metal and the peak. So that, we designed to be base on high frequency transformer and reactor of DC part. Then, we optimized control of PWM, current rising slant, voltage, current, pulse current and inverter out-put voltage. Also we designed PCB for EMI and noises.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.771-773
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• 2003

본 논문에서는 대전력 150KVA급의 mash seam 용접기에 용접 센터링등 여러 가지 용접 효율 향상을 위한 부가 장치를 포함한 용접장치 개발을 통한 용접품질 분석결과를 보이고 있다. 일반적으로 제철소에 사용되는 수100KVA급의 용접기들은 그동안 전량 수입에 의존하던 것을 공동연구론 통해서 국산화에 성공하였다. 본 시스템은 기존의 타사제품의 기능을 포함하여 용접 센터링 장치, 용접 전후단의 크램핑기능, 선후행 코일의 선단부를 절단하는 shearing 기능, 용접 휠높이 자동조절기능을 포함하였으며, 자체 설계된 대전력용 변압기, 대전력 절환용 thyristor 제어들을 포함한 용접기로써 기존의 타사제품에 비하여 기능적, 성능적으로 향상된 형태로써 용접성능 검사에서도 양호한 결과 얻었다. 본 논문에서는 mash seam 용접기의 기본적인 기능설명과 개발된 용접기를 기능별로 설명하고, POSCO 현장적용 결과를 간략히 소개한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1242-1244
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• 2004

As rapid growth of energy demand in line with modem society's industrialization led to environmental pollution by fossil fuels, there are more and more interest and international research on energization of water, which is clean energy and comprising $70\%$ of earth. In offshore countries, the water is commercially used already and water has very attractive characteristics in terms of economy and efficiency compared to the existing gas welder. In this paper, the result from operating characteristic improvement of Gas Generator and Current-Controlled converter is to be considered into design in electrode, source and controller, standized into level of whole system design base.