• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.5-9
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• 2003

Conventional variable-speed Induction motor drives with inverters are subject to detrimental effect of zero-sequence voltages, such a shaft voltage and bearing current. This paper presents a way of the suppression of the zero-sequence components in multilevel H-bridge inverters. First examined Is the inherent zero-sequence characteristic of the conventional subharmonic PW method. Then it is shown that the zero-sequence voltage can be eliminated with proper -selection of switching states with space vector modulation. Although this method alone restricts the linear modulation range of control, a combination of the proposed method and the minimum switching method appears to be effective in suppressing the zero-sequence voltage to minimum level while maintaining the linear control range.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.307-313
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• 2002

In the paper, the prototype development of a 75kW class microturbine for the distributed generation market is partly presented which has continued with the government funding. In the introduction, an overview of the development of microturbines in the world is presented. A series of development procedures are shown with design, manufacture and self-sustaining tests. During the first year, aerodynamic and structural design/analysis, mechanical design are performed for the compressor, the turbine and the combustor. A premixed lean burn combustor technology is used fur the low emission requirements. Foil air bearings and high-speed motors are employed for higher reliability. The self-sustaining conditions have been successfully achieved with the prototype manufactured engine as a preceding operation.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.177-182
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• 2002

In the paper, the development of high-speed industrial turbo blowers with foil air bearings is presented as a first successful commercialization in the world. Their target market is various from wastewater treatment to cement factory processes which require compressed air ranging between 0.6 and 0.8 bar gauge. Employing the state-of·the-art technology of the high-speed BLDC motors, the bump-type foil air bearings and the high- efficient turbo impellers/diffusers, so much compact, efficient and silent blower machines of a single stage are now available in the market, aiming to replace the existing inefficient, bulky and noisy ones, such as roots blowers. The first production lines are established fur 25,75 and 150 hp class blowers. Rotational speeds from about 20,000 to 80,000 rpm are realized directly from the high-speed BLDC motors without any gear boxes, and no lubrication oil is required. A brief introduction of design, manufacture and test results is presented fur mechanical, electrical and aerodynamic performance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.100-103
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• 2002

The recent machine tools are requested so high-quality processing and productivity increasing. Therefore it is so necessary to develop technology far high-speed and high-precision. This thesis touches on the development of high speed and intellectual line center. At first, the line center is necessary that strong structure, compact structure and light weight design far high-speed processing and transfer. So. It is necessary that examination of new materials and structures for light-weight and control devices for precision processing. So. It is going to make mention of the process of 1st model production for the above-mentioned base on test model production and evaluation.

• 한국철도학회논문집
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• 제2권2호
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• pp.13-20
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• 1999

The vibration signals of driving parts of electric train are distorted its signal patterns due to the impact components, which occurs when wheel passes rail joints. An elimination method of the impact components is investigated using adaptive signal processing technique in this study The result shows that adaptive interference canceling method seems to be more effective than line enhancement technique. The application of adaptive interference canceling method to the signal measured at bogie shows that the extractions of the signals of driving parts of traction motor, reduction gear, and axle bearing are successful. Therefore, only the signals of bogie, which is the place to attach an accelerometer easily, is sufficient for the fault diagnosis and the safety evaluation of electric train. Also, adaptive interference canceling method can be applicable to evaluate the performance of vibration isolation between bogie and car body and to investigate the characteristics of indoor sound.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.436-440
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• 1996

In this study, underdeveloping heavy-load driving servo control system, which are composed of controller, electro-hydraulic servo-valve, hydraulic motor, reduction gear box, turret slew bearing and turret structure, are investigated to simplify the control system. To estimate the effect of each component, modeling and simulation of linear and nonlinear system are carried out. In the first stage, to prove the reliability of performance estimation program, simulation results are compared with experimental results. In the second stage, the effect of each component of control system is evaluated and then a simplified control system is suggested.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.717-722
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• 2003

To improve the shock resistance of the microdrive under non-operating conditions, an isolator was attached to the contacting part of the microdrive. Through FE analysis, design parameters for satisfying the allowable acceleration level of the spindle motor bearing part were presented, which is a most possible critical part of the microdrive.

• 한국공작기계학회논문집
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• 제11권5호
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• pp.7-14
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• 2002

In order to achieve high precision machine tools, the research for performance enhancement of feed drive systems is required. Development of the high speed feed drive system has been a major issue for the past few decades in machine tool indestries. Because table levitation system decrease the table weight, an effect of reaction by weight is minimized and lost motion can be removed at maximum. In case fled system is designed with drive motor, ball screw and support bearing load capacity selection, an effect of decrease of the table weight exist. So, the table weight through an effect of decrease call it into the realization of cost down. Stick-slip friction has a great influence on the contouring accuracy of CNC machine tools. In this paper table levitation system has been developed for the stick-slip in a fled drive systems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.274-279
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• 2009

Reduction Gear Box where from productive site uses the gear with power delivery with high mechanical efficiency of power a deceleration and as the mechanical element union product which has the velocity ratio which is various together is produced with the power occurrence motor and leads gets a high driving force is plentifully used. The above occurs from gear drive issue sound Whine, Noise and Vibration as occurring from the rim process which the gear will bite mainly is delivered with the case etc. gear drive whole which leads the axis and the bearing. The productivity falls with the going straight rate decrease which with like this problem point is caused by with rework the problem point where the cost of production rises under improving boil many kinds analyzed the plan and investigates the resultant acceleration sensor which and a frequency analysis system and was made to apply.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.56-59
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• 1997

The recent machine tools are requested so high-quality processing and productivity increasing. Therefore it is so necessary to develop technology for high-speed and high-precision. This thesis touches on the development of high speed and intellectual line center. At first, the line center is necessary that strong structure, compact structure an light weight design for high-speed processing and transfer. So. It is necessary that examination of new materials and structures for light-weight and control devices for precision processing. So. it si going to make mention of the process of 1st model production for the above-mentioned base on test model production and evaluation.