• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.960-966
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• 2007

High-efficient machining, which means to machine a part in the least amount of time, is the most effective tool to improve productivity. In this study, a new feed optimization method based on virtual manufacturing was proposed to realize the high-efficient machining in turning process through the cutting power regulation. The cutting area was evaluated by using the Boolean intersection operation between the cutting tool and workpiece. And the cutting force and power were predicted from the cutting parameters such as feed, depth of cut, spindle speed, specific cutting force, and so on. Especially, the reliability of the proposed optimization method was validated by comparing the predicted and measured cutting forces. The simulation results showed that the proposed optimization method could effectively enhance the productivity in turning process.

• Journal of Welding and Joining
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• v.22 no.6
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• pp.6-9
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• 2004

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.21-30
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• 2017

Of the marine engine components, the piston crown and exhaust valve are repaired most frequently. These works are conducted through conventional welding processes such as GTAW or SAW, domestically in marine engine repair factories. New high-efficiency welding or overlay processes such as tandem SAW, tandem MAG, hybrid TIG-MIG welding, pulsed-GMAW, CMT welding, and super TIG welding have been developed recently. Moreover, the plasma transfered arc (PTA) process is an efficient spray method for overlaying on the exhaust valve. In this review paper, the new high-efficiency repair welding methods are introduced for marine engine components. The problems due to repair welding for marine engine components are also presented.

• JOURNAL OF ELECTRICAL WORLD
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• s.439
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• pp.65-65
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• 2013

• 기계와재료
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• v.2 no.4 s.6
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• pp.142-148
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• 1990

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.186-192
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• 1998

This paper presents a high performance low switching PWM technique or the propulsion system of railway such as subway and high speed train. In order to achieve the continuous voltage control to six-step and s low harmonics with low switching frequency under 500Hz, the synchronous technique is combined with a space vector overmodulation and implemented by using DSP. Improved performance and a validation of proposed method are showed by the digital simulation and the experimental results using a 1.65MVA IGBT VVVF inverter and inertia load equivalent to 160 tons railway cars.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.123-124
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.389-390
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• 2008

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.2 s.233
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• pp.333-340
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• 2005

Feedrate is one of the factors that have the significant effects on the productivity, qualify and tool life in the cutting mechanism as well as cutting velocity, depth of cut and width of cut. In this study, in order to realize the high-efficient machining, a new feedrate optimization method is proposed based on the concept that the optimum feedrate can be derived from the allowable cutting power since the cutting power can be predicted from the cutting parameters as feedrate, depth of cut, width of cut, chip thickness, engagement angle, rake angle, specific cutting force and so on. Tool paths are extracted from the original NC program via the reverse post-processing process and converted into the infinitesimal tool paths via the interpolation process. And the novel NC program is reconstructed by optimizing the feedrate of infinitesimal tool paths. Especially, the fast feedrate optimization is realized by using the Boolean operation based on the Goldfeather CSG rendering algorithm, and the simulation results reveal the availability of the proposed optimization method dramatically reducing the cutting time and/or the optimization time. As a result, the proposed optimization method will go far toward improving the productivity and qualify.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.138-145
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• 2009

High-efficiency and high-quality machining has become a fact of life for numerous machine shops in recent years. And high-efficiency machining is the most significant tool to enhance productivity. In this study, to achieve high-efficiency machining in turning process, a spindle speed optimization method was proposed based on a cutting power model. The cutting force and power were estimated from the cutting parameters such as specific cutting force, feed, depth of cut, and spindle speed. The time delay due to the acceleration or deceleration of spindle was considered to predict a more accurate machining time. Especially, the good agreement between the predicted and measured cutting forces showed the reliability of the proposed optimization method, and the effectiveness of the proposed optimization method was demonstrated through the simulation results associated with the productivity enhancement in turning process