• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1338-1343
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• 2007

High-efficient machining, which means cutting 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 the cutting power regulation was proposed to realize the high-efficient machining in turning process. 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.

• 제어로봇시스템학회논문지
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• 제16권8호
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• pp.771-779
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• 2010

This paper presents a method that integrates the geometric path tracking and the obstacle avoidance for nonholonomic mobile robot. The mobile robot follows the path by moving through the turning radius given from the pure pursuit method which is the one of the geometric path tracking methods. And the obstacle generates the obstacle potential, from this potential, the virtual force is obtained. Therefore, the turning radius for avoiding the obstacle is calculated by proportional to the virtual force. By integrating the turning radius for avoiding the obstacle and the turning radius for following the path, the mobile robot follows the path and avoids the obstacle simultaneously. The effectiveness of the proposed method is verified through the real experiments for path tracking only, static obstacle avoidance, dynamic obstacle avoidance.

• 대한기계학회논문집A
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• 제31권9호
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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.

• 한국생산제조학회지
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• 제21권5호
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• pp.842-847
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• 2012

The Response Surface Method(RSM) is used as optimal design technique of experimental conditions. In Al7075-T0 turning operation, the principle cutting force and the Center-line averaged roughness are measured to optimize machining process. In variation of feed, depth of cut and cutting speed, three cutting parameters are evaluated. The optimal cutting conditions of Al7075-T0 turning are suggested by RSM. As a main result, feed is the dominant cutting parameter in this turning process considering surface roughness and cutting force.

• 한국기계가공학회지
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• 제10권6호
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• pp.1-8
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• 2011

Recently, super heat-resistant alloy Inconel 600 come into spotlight as the material of airplane parts but this material causes lots of problems that is, reduction of machinability and attritious wear and breakage of cutting tool during turning processing due to high temperature strength and cohesion between tool material and Inconel 600. Therefore, in this study, it was purposed to determine tool material kind and to select of proper cutting range when turning process was carried out for Inconel 600. In order to these Purpose, coated carbide tool and ceramic tool was used in this experiment and the machinability of Inconel 600 was investigated from perspective of the cutting force, chipping and wear of tool and deposition phenomenon of chip.

• 한국기계가공학회지
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• 제11권6호
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• pp.36-41
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• 2012

In this study, we turning plastic mold steel (STAVAX) against cutting speed, depth of cut, feed rate using whisker reinforced ceramic tool (WA1). To predict cutting force, analyze principal, radial, feed force with multi-regression analysis. Results are follows: From the analysis of variance, affected factor to cutting force feed rate, depth of cut, cutting speed in order and cutting speed was very small affect to cutting force. From multi-regression analysis, we extracted regression equation and the coefficient of determination$(R^2)$ was 0.9, 0.88, 0.856 at principal, radial and feed force. It means regression equation is significant. From the experimental verification, it was confirmed that principal, radial and feed force was predictable by regression equation.

• 대한조선학회논문집
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• 제53권3호
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• pp.217-227
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• 2016

Recent accidents of crude oil tankers have resulted in sinking, grounding of vessels and significant levels of marine pollution. Therefore, International Maritime Organization (IMO) has been strengthening the regulations of ship maneuvering performance in MSC 137. The evaluation of maneuvering performance can be made at the early design stage; it can be investigated numerically or experimentally. The main objective of this paper was to investigate the maneuvering performance of a VLCC due to the increase of rudder force at an early design stage for low speed in shallow water conditions. It was simulated in various operating condition such as deep sea, shallow water, design speed and low speed by using the numerical maneuvering simulation model, developed using MMG maneuvering motion equation and KVLCC 2 (SIMMAN 2008 workshop). The effect of increasing the rudder force can be evaluated by using numerical simulation of turning test and ZIG-ZAG test. The research showed that, increasing the rudder force of a VLCC was more effective on improving the turning ability than improving the course changing ability especially. The improvement of turning ability by the rudder force increasing is most effective when the ship is sailing in shallow water at low forward speed.

• 한국공작기계학회논문집
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• 제15권4호
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• pp.83-91
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• 2006

At present, industry and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. One of the technologies is known as MQL(Minimum Quantity Lubrication) machining. This research presents an investigation into MQL machining with the objective of deriving the optimum cutting conditions for the turning process of SM4SC. To reach these goals several finish turning experiments were carried out, varying cutting speed, feed rate, oil quantity and so on, with MQL and flood coolant. The surface roughness and cutting force results of tests were measured and the effects of cutting conditions were analyzed by the method of Analysis of Variance(ANOVA). From the experimental results and ANOVA, this research proposed optimal cutting conditions to improve the machinability in MQL turning process.

• 한국기계가공학회지
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• 제12권1호
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• pp.63-69
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• 2013

Many researchers are trying to reduce the use of lubrication fluids in metal cutting to obtain safety, environmental and economical benefits. The aim of this study is to determine the optimization lubrication conditions in minimum quantity lubrication(MQL) turning of workpieces with taper angle. This study has been considered about various conditions of MQL. The objective functions are cutting force and surface roughness. Design factors are nozzle diameter, nozzle angle, MQL supply pressure, distance between tool and nozzle and length of supply line. The cutting force and surface roughness were statistically analyzed by the use of the Box-Behnken method. As a results, optimum lubrication conditions were suggested and verification experiment has been performed. The results of this study are expected to help the selection of lubrication conditions in MQL turning.

• 한국산업융합학회 논문집
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• 제3권2호
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• pp.123-130
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• 2000

Fuzzy control is proposed to regulate cutting force in turning operations under varying cutting conditions. The traditional linear controllers based on crisp mathematical model cannot effectively control cutting force becasue of the nonlinear dynamics of turning operations. The proposed fuzzy controller is based on operator experience and expert knowledge. The membership functions for the inputs and the output of the controller are designed. Cutting force is regulated by adjusting feedrate according to the variation of cutting conditions. The performance of the proposed controller is evaluated by experiments. The results of experiments show that the proposed fuzzy controller has a good cutting force regulation over a wide range of cutting conditions.