• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1038-1043
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• 1997

To adapt the neural network proess for the purpose of determination of optimal utting onditions (optimal cutting speed and feed rate), some selection strategies for the machining factors are necessary, which is considered planning cutting process. In this case, factors that have both nonlinearity and strong relationship must be selected. Although tool grade and chemical properties of workpiece material have strong effect to cutting speed, it's not easy to find a analytic relation between them. In this paper, a mathematical method for determining the optimal amount of cutting (depth of cut, feed rate) is presented by tool goemetry and heat generation during cutting process. And various tool grade and workpiece material groups ase classified based on its chemical properties. Thier chemical composition and hardness are used as input pattern for neural network learnig. The result of learning shows the relationship between tool grade and workpiece material and it is proved that it can be used as a sub-system for automatic process planning system.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.43-50
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.407-408
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• 2009

• Journal of the Korean Home Economics Association
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• v.20 no.3
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• pp.9-18
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• 1982

In this study, we attempted to make an original pattern of clothing for an abnormal type of figure, especially for the type of kyphosis. We measured the curvature of the spine of a woman with kyphosis with a Martin measuring instrument and a silhouetter in the following ways. First, we counted the rate of shrinkage of the standard lines drawn on the surface of the body according as the body moved. Secondly, placing the front and back darts, the front and back shoulder darts and the side darts according to“Munhwa”pattern, we made cubic cuttings of four moving postures as well as the standing one. Thirdly, we superposed the developed patterns of the standing and the moving postures, measuring the position change and the amount of the chaange of the darts, and compared them. The results are as follows: 1) In the developed pattern of a cubic cutting of the basic pattern and the standing posture, the neckhole became larger than that of the basic pattern, and the waist line was lowered than that of the basic pattern because the center back line was shortened due to the curved backbone. 2) As for the change of the standard line according to the movement, we found that the waist line, the center front line, the center back line, the bust width line, the upper back width line and the back width line became longer. Special consideration must be given to the function of the clothing for an abnormal type of figure. 3) The difference of the measurements between the cubic cutting and the body measurement regardless of the body movement is due to a gap by an acute angle at the jutted place between the developed pattern and the body surface. We found that the body measurement of the upper back width line, the back width line and the bust line became larger. Consequently, in making an original clothing pattern, it is desirable that we must not place the front and the back waist darts at the jutted place on the back from the functional and the aesthetic viewpoint of clothing. It is also desirable that we must widen the neckhole because the shoulder angle is close to a straight line due to a jut of the upper back width line.

• Design & Manufacturing
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• v.14 no.3
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• pp.63-70
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• 2020

As the consumer market in the VR(virtual reality) and the head-up display industry grows, the demand for 5-axis machines and grooving machines using on a ultra-precision machining increasing. In this paper, ultra-precision diamond tools satisfying the cutting edge width of 500 nm were developed through the process research of a focused ion beam. The material used in the experiment was a single-crystal diamond tool (SCD), and the equipment for machining the SCD used a focused ion beam. In order to reduce the influence of the Gaussian beam emitted from the focused ion beam, the lift-off process technology used in the semiconductor process was used. 2.9 ㎛ of Pt was coated on the surface of the diamond tool. The sub-micron tool with a cutting edge of 492.19 nm was manufactured through focused ion beam machining technology. Toshiba ULG-100C(H3) equipment was used to process fine-pattern using the manufactured ultra-precision diamond tool. The ultra-precision machining experiment was conducted according to the machining direction, and fine burrs were generated in the pattern in the forward direction. However, no burr occurred during reverse machining. The width of the processed pattern was 480 nm and the price of the pitch was confirmed to be 1 ㎛ As a result of machining.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.4
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• pp.61-70
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• 2005

In this Paper, we develop an improved branch and bound algorithm for the (un)weighted unconstrained two-dimensional cutting problem. In the proposed algorithm, we improve the branching strategies of the existing exact algorithm and reduce the size of problem by removing the dominated pieces from the problem. We apply the newly Proposed definition of dominated cutting pattern and it can reduce the number of nodes that must be searched during the algorithm procedure. The efficiency of the proposed algorithm is presented through comparison with the exact algorithm known as the most efficient.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.344-348
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• 1992

This paper presents a new methodology for on-line tool breakage detection by sensor fusion concept of an acoustic-emission (AE) sensor. A built-in piezoelectric force sensor was used to measure cutting force instead of a tool dynamometer to preserve the machine tool dynamics. he sensor was inserted in the tool turret housing of an NC lathe. FEM analysis was carried out to locate the most sensitive position for the sensor. When a tool is broken, the explicit changes of signals' pattern take place. A burst-type AE signal increases abruptly. Followingly, a cutting force drops significantly. Therefore a burst of AE signal is used as a triggering signal to inspect the following cutting force. Significant drop of cutting force is utilized to detect tool breakage. The algorithm was implemented in a DSP board for in-process tool breakage detection. The proposed monitoring system was capable of a good applicable tool breakage detection.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.75-78
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• 1996

End Milling is avilable for machining the variable shape of products and has been widely applicated in many industries. To manufacture precise products a surface roughness has to be noticable as a improtant parameter. In end milling the research for tool wear has been insufficient because the tool shape and the cutting geometry are complicated. In this paper the pattern of endmill wear is investigated and the machinability is evaluated. As finding out the characteristics of cutting force and surface roughness the effect of endmill wear on machinability is investigated.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.806-812
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• 2008

Many kinds of rolling-stocks that have various control methods are being operated by Seoulmetro which is a history of a city railroad rolling-stock. Seoulmetro is being faced with a wheel management comparing of other lines with a perpendicular wear of wheel and a side damage, and so on, by operating several cars at a loop line. This is causing maintenance expenses increase and deteriorating a fusibility of rolling-stock, for it has an effect on a rolling-stock using. A cutting pattern of wheel and a wear form affect the expected span of a wheel. A wheel cutting cause is classifed into cutting for reprofiling of a flange wear of wheel and for removing every kind defect which originates from wheel wear. In this study, Seoulmetro exhibit a stable rolling-stock use method and a reasonable management method of wheel, analysing wheel exchange condition and cutting management of wheel.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.989-996
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• 2008

The purpose of this study is to provide the basic knowledge for the pattern development of a flared skirt. Two flat pattern (FP) methods, the concentric circle method and the corrected concentric circle method, and a draping were used for pattern making. Using these patterns, skirts were made with lengthwise grain in the centerline. The influence of pattern making method on the silhouette of the flared skirt was evaluated by the hemlines formed at the skirt worn in a dress form. Moreover, the combined influence of pattern making method and cutting direction on the silhouette of the flared skirt was examined with the draping pattern (DP) skirt and a FP skirt with $45^{\circ}$ bias grain in the centerline. The DP skirt had more uniform nodes and formed a stable wave form than the FP skirts throughout the whole hemlines. The number of nodes was reduced with lining in the two FP skirts, whereas the number of nodes was not changed in the DP skirt. The unit wave form of all the skirts by three patterns showed long loop form, and the slope angles of the unit wave form of the two FP skirts were higher than that of the DP skirt. The silhouette of the flared skirt was highly influenced by the shape of the waist circumference line in patterns. The DP skirt with lengthwise grain in the centerline showed good silhouette with uniform nodes and high marking efficiency, compared to the FP skirt with $45^{\circ}$ bias grain in the centerline.