• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.28-41
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• 1994

An efficient algorithm is proposed to select the proper tools and generate their paths for NC rough cutting of dies and molds with sculptured surfaces. Even though a milling process consists of roughing, semi-finishing, and finishing, most material is removed by a rough cutting process. Therfore it can be said that the rough cutting process occupy an important portion of the NC milling process, and accordingly, an efficient rough cutting method contributes to an efficient milling process. In order work, the following basic assumption is accepted for the efficient machining. That is, to machine a region bounded by a profile, larger tools should be used in the far inside and the region adjacent to relatively simple portion of the boundary while smaller tools are used in the regions adjacent to the relatively complex protion. Thus the tools are selected based on the complexity of the boundary profile adjacent to the region to be machined. An index called cutting path ratio is proposed in this work as a measure of the relative complexity of the profile with respect to a tool diameter. Once the tools are selected, their tool paths are calculated starting from the largest to the smallest tool.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.354-361
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• 2005

In high speed cutting process, due to the friction between the tool and workpiece, a temperature rise of contacting part is serious. It need to develop cutting tool for overcoming such a poor condition. So now, some studies, the optimization of tool shapes, the fine grains of tool material, multi-layer coating of tools are processing. If mirror finishing on the tool is processed, there is advantage of relation between chip and tool, because of less friction, and also tool's lift would be increased. As a result mirror like finishing is expected efficient enhancement of tool. Generally, it is too difficult to process by a general way for tools of complex shapes, it is required a new method to process such complex shape tools. The magnetic fluid polishing technique can polish the workpiece 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. In this paper, We polished the surface of the high speed cutting tool using the magnetic fluid polishing technique, to enhance the performance of the high speed cutting tool.

• Fibers and Polymers
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• v.4 no.2
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• pp.71-76
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• 2003

We evaluated the seam characteristics with finishing, seaming and sealing processes and seam Puckering behavior of the breathable waterproof fabrics with laser scan. There were differences in 99% significant level between the seamed fabric and the sealed fabric. Seam breakage was initiated with the breakage of sewing thread, so the seam strength after seaming was almost uniform. The sewn seam strength and elongation increased with sealing process in all finishing methods. Pucker grade of laminating type was generally much higher than that of the coating type. We confirmed that wave length and amplitude have more important meaning than the number of weave in the breathable waterproof fabrics. The puckering in breathable waterproof fabrics is mainly occurred by inherent and feeding pucker. The former if due to the insertion of sewing thread and the littler is caused by differential feeding when two pieces of fabric are fed into the gap between a press foot and needle plate.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.129.4-129
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• 2001

The looper control of hot strip finishing mill is one of the most important control item in hot strip rolling mill process. Loopers are placed between finishing mill stands and control the mass flow of the two stands. Another important action of the looper is to control the strip tension which influences on the width of the strip. So it is very important to control both the looper angle and the strip tension simultaneously but the looper angle and the strip tension are strongly interacted by each other. There are many control schemes such as conventional, non-interactive, LQ(Linear Quadratic), Hinf and ILQ(Inverse Linear Quadratic), Adaptive(gain scheduling) control in the looper control system. In this paper, we present the modeling for the looper of a hot strip finishing mill to control the tension of the strip and suggest another control method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.970-976
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• 1997

The ultra-precision machining is widely used for final machining process of precision parts, so in this study, mirror surface finishing systems using the micro abrasive film, one of ultra-precision machining method, have to examine mirror surface characteristics of the cylindrical workpiece(SM45) such as surface roughness, workpiece removal and evaluated under the condition varing film feed rate, applied pressure, grinding speed after fixing other condition. It was found that varrious machining condition have significant influences on workpiece removal, surface roughness.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.04a
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• pp.97-102
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• 2009

In hot strip rolling, sound prediction of the temperature of the strip is vital for achieving the desired finishing mill draft temperature (FDT). In this paper, a precision on-line model for the prediction of temperature distributions along the thickness of the strip in the finishing mill is presented. The model consists of an analytic model for the prediction of temperature distributions in the inter-stand zone, and a semi-analytic model for the prediction of temperature distributions in the bite zone in which thermal boundary conditions as well as heat generation due to deformation are predicted by finite element-based, approximate models. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model.

• Journal of Fashion Business
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• v.15 no.6
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• pp.101-112
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• 2011

Three-dimensional(3D) virtual clothing simulation system may require the use of physical, mechanical, and configurational data in order to mimic the actual clothing with high degree of realism. Therefore the 3-dimensional scanning system based on optical methods was adopted to extract the 3-dimensional data of the fabric surface. In this study, the appearances of the 3-dimensionally transformed textile fabrics via several finishing procedures were investigated using a 3D scanning system. The wool gauze fabrics treated with the shrink-proof finishing and the felting process showed height changes up to 4.5mm. The 3-dimensional configuration may be objectively described by the use of mesh generation from the scanned output. The generated mesh information may further be utilized in the 3D virtual clothing simulation system for accurate description of the fashionable textile materials used in the simulation system.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2267-2269
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• 2001

The looper control of hot strip finishing mill is one of the most important control item in hot strip rolling mill process. Loopers are placed between finishing mill stands and control the mass flow of the two stands. Another important action of the looper is to control the strip tension which influences on the width of the strip. So it is very important to control both the looper angle and the strip tension simultaneously but the looper angle and the strip tension are strongly interacted by each other. There are many control schemes such as conventional, non-interactive, LQ, LQG/LTR, and ILQ control in the looper control system. In this paper, we present the modeling for the looper of a hot strip finishing mill to control the tension of the strip and suggest the non-interactive(cross) and LQG/LTR control method.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.385-391
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• 2017

The warranty liability period for defects in apartment buildings by work type is not based on scientific analysis, making the appropriateness of the term a culprit behind the lawsuits. Therefore, this research aims to evaluate the appropriateness of the warranty liability term of apartment buildings by identifying the current status of defects, in particular, caused by finishing works. That is because the number of defects, caused during the finishing works, accounted for the largest portion of the total defect cases of apartment buildings reported to the Apartment Defect Dispute Mediation Committee under the Ministry of Land, Infrastructure, and Transport of Korea between 2010 and 2011. The result from analyzing claims for defect repairs of the finishing works showed that most cases by work type continued to be made after two years, and only about 60% were charged within the warranty period. And, defects by work type have correlation, which needs to be considered for a better construction technique. Considering a low correlation between the possibility of defects and the construction performance rankings, which are highly relevant to the apartment preference. It is believed that there needs to be a qualification process for agencies that actually performs finishing works.

• Textile Coloration and Finishing
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• v.27 no.1
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• pp.11-17
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• 2015

Recently, super fiber reinforced composite materials are widely used in many industries due to high mechanical properties. In this study, 2 different types of composite materials were manufactured in order to compare their mechanical properties. Carbon and Aramid fibers were used for reinforcement materials and Bisphenol-A type epoxy resin was for matrix. Two kinds of fiber-reinforced materials were manufactured by RIM(Resin Injection Molding) method. Before manufacturing composite materials, the optimal manufacturing and curing process condition were established and the ratio of reinforcement to epoxy resin was discussed. FT-IR analysis was conducted to clarify the structure of epoxy resin. Thermal and mechanical property test were also carried out. The cross-section of composite materials was observed using a scanning electron microscope(SEM).