• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.1
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• pp.32-38
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• 2006

The magnetic fluid polishing technique can polish the tool of complex shape, because the polishing method which polishes as compress the workpiece by the magnetism abrasives to arrange to the linear according to the line of magnetic force. Therefore, we producted the magnetic fluid polishing device in order that mirror like finishing processes the tool surface. In order to a polishing condition selection, polishing characteristic was estimated by polishing conditions which are magnetic flux density, polishing speed, grain size, magnetic fluid. The tool was polished to the selected polishing condition. The result to evaluate the polished tool's performance with the cutting force and tool wear, the polished tool's performance was improved compared with the tool not to polish.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.12
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• pp.71-77
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• 1999

In this study, Cu ferrite was machined with cermet tool to clarify the machinability. The main conclusions obtained were as follows. The tool wear becomes the smallest at the cutting speed of 90m/min with the depth of cut of 0.2mm. The surface roughness becomes larger with increasing the cutting speed and the chamfer angle. The tool with the chamfer angle of $15{\circ}$ shows the best performance. The surface roughness increases almost proportionally with the increase of the chip size. The tool wear decreases with increasing feed in the depth of cut not more than 0.2mm.

• 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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• 2000.11a
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• pp.963-966
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• 2000

Abrasive jet machining(AJM) process is similar to the sand blasting, and effectively removes hard and brittle materials. AJM has applied to rough working such as deburring and rough finishing. As the needs for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM was developed, and became the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro groove cutting of glass. Diameter of hole and width of line in this groove cutting is 80${\mu}{\textrm}{m}$. Experimental results showed good performance in micro groove cutting in glass, but the size of machined groove was increased about 2~4${\mu}{\textrm}{m}$. therefore, this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD parts.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.767-770
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• 2000

A novel process is newly developed for building RP(Rapid Prototyping) parts using a sheet lamination technique. The build process of existing sheet lamination type RP machines consists of the following steps : feeding, lamination and cutting. In this process, the laminated part of an object is often scratched by a cutter or damaged by a laser beam due to the cutting operation preceded by lamination, In addition, decubing of the unused portion from the laminated block is difficult. In the new process, cutting operation is performed before lamination. The cutting operation takes place while a paper sheet is firmly attached on the plate using electrostatic force. Then liquid glue is applied to the calculated region of the given contour for lamination. The process aims to manufacture a $2k RP machine, what we call the Freeform Mater I, that can use A4 or latter-size used papers. A prototype machine that demonstrates the design concept is built and further research issues are discussed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.225-229
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• 2000

Burrs formed during face milling operations are very hard to characterize like other machining burrs because there are many parameters which affect the cutting process. Many researchers have tried to predict burr characteristics including burr size and shapes with various experimental conditions such as cutting speed, feed rate, in-plane exit angle, number of inserts, etc., but it still remains as a challenging problem for the complicated combination effects between the parameters. In this paper, Taguchi method, which is a systematic optimization application of design and analysis of experiments, is introduced to acquire optimum cutting parameters for burr minimization. Optimized experimental conditions are provided to show the effectiveness of this approach.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.6
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• pp.110-116
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• 2005

A single-piece-machined-part has superior characteristics to an assembly of several pieces of part especially for aircraft components. It is necessary to develop high efficient 'multi-head router machine' for machining a large size single-piece-part on a large scale. In this type machine, many cutting chips are generated. These chips should be removed automatically f3r productivity and part precision. In this study, the design evaluation of the cutting chip collecting apparatus for 'multi-head router machine' was complemented using performance test and finite element analysis.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.4
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• pp.741-751
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• 1996

The three dimensional cutting-stock problem is to maximize the total value of pieces which are smaller cubics-cut from a original cubic stock. This paper suggests a method to maximize the total value of different size cut pieces using the orthogonal non-guillotine cut technique. We first formulated a zero-one integer programming, then developed a Lagrangeon relaxation method far the problem. The solutions were given by using a brunch-end-bound technique associates with Lagrangean relaxation, which guarantees an optimal solution.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.68-74
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• 1999

The influence of surface preparation methods after plasma cutting on the quality of weld zone was investigated. For comparison, three types of welded specimens were prepared by machining (WM), plasma cutting with light regrinding (WPG) and without regrinding (WP), by using three kinds of materials, carbon steel (SM45C), stainless steel (STS304) and aluminum alloy (A6061-T6). Nondestructive examination, hardness test, microstructure examination, and fracture toughness test were performed. The results showed that there was no appreciable reduction in hardness or fracture toughness in WP specimens. But a little difference in heat affected zone size was observed.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.27-38
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• 1995

For solving troubles happened during the drilling process with carbon fiber epoxy composite materials(CFRP) by using HSS drill, a few types of diamond gift electroplated drills are manufactured, and machinability of these drills is experimented with a variety of cutting speed and feed rate. These drills have some advantages of good wear resistant and the conception of grinding process. As a result, using of these drills improves both troubles being caused by tool wear and damage of exit surface depending on fiber stacking angle. It is desirable that cutting conditions for the cutting thickness per revolution must be set under 0.01mm when the size of a diamond grit is # 60 .approx. 80.