• Transactions of Materials Processing
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• v.20 no.3
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• pp.206-213
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• 2011

A flexible die, which is composed of a number of punches with adjusted heights to form a three-dimensional curved surface, is a crucial part of a flexible forming technology. In this study, the punch and control system of the flexible die were designed. The flexible die is divided into three modules, namely, punch, control and joint, and the corresponding modules were developed. The punch module materializes a three-dimensional forming surface by the control module, which is composed of an AC servo motor set and a linear guide. The joint module is necessary for the sequential motion between the servo motor set and the punch module. A sequential motion algorithm for the AC servo motor set, that uses the data of the punch relative heights, was also proposed. Finally, a flexible stretch forming test was carried out using the presently designed flexible die.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.4
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• pp.550-553
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• 2006

This study used the 3D CAD/CAM system in manufacturing die plates to improve productivity. UG NX 3.0 was used as 3D CAD/CAM software, with the created NC code transmitted to the CNC Milling and Wire Cut Electric Discharge machine. The die plate was then automatically machined.

• Transactions of Materials Processing
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• v.30 no.4
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• pp.172-178
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• 2021

The cold forging process induces material deformation in an enclosed space, generating a very high forging load. Therefore, it is mainly designed as a multi-stage process, and fatigue failure occurs in forging die due to cyclic load. Studies have been conducted previously to quantitatively predict the fatigue limit of cold forging dies, however, there was a limit to field application due to the large error range and the need for expert intervention. To solve this problem, we conducted a study on the introduction of a real-time forging load measurement technology and an automated system for quantitative prediction of die life cycle. As a result, it was possible to reduce the error range of the quantitative prediction of die life cycle to within ±7%, and it became possible to use the die life cycle calculation algorithm into an automated system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.303-306
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• 2000

This paper describes a research on the development of the 3D design automation system for progressive die. Based on knowledge base of expert, this system can carry out design tasks, such as feature recognition of product data, layout design, dre set component design. Easy system user mterface and 3-dlmensional solid modeling could result in time and cost saving.

• Korean Journal of Computational Design and Engineering
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• v.3 no.4
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• pp.223-235
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• 1998

A dedicated CAM(Computer-Aided Manufacturing) system has been developed, which generated tool-path to machine Styrofoam stamping die-patterns in Chrysler Corporation. A previous process to build die-patterns was to "stick build" the pattern, in which stock is cut & glued together, and then the NC machining of part-surface shape completes building a Styrofoam die-pattern. The current process utilizes the developed CAM system, and almost removes the manual work, consequently reduces the overall lead time. The paper presents the overall system structures, tool-path generation, and some features of Styrofoam pattern machining.

• Journal of Korean Theatre Studies Association
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• no.48
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• pp.171-196
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• 2012

In der vorliegende Arbeit wird die neue politische $M{\ddot{o}}glichkeit$ des Theaters untersucht. Wie die politische Propaganda, die Volk mit den absoluten Dogmen zu ${\ddot{u}}berzeugen$, immer seltner geworden ist, haben die alten Versuche des Theaters, ein Publikum mit einem Botschaft $aufzukl{\ddot{a}}ren$ und zu ${\ddot{u}}berreden$, ihre ehemalige ${\ddot{U}}berzeugungskraft$ verloren. In der heutigen Welt kann Theater leider nicht als eine moralische Anstalt mehr funktioniert. An diesem Endpunkt, wo Theater heute anzukommen scheint, gibt es aber auch Versuche, Theater auf neue Weise politisch zu machen. Es handelt sich hier $nat{\ddot{u}}rlich$ nicht um Wiedergabe einer ideologischen Diskurs mehr, sondern um die $St{\ddot{o}}rung$ der Wahrnehmung der Zuschauer durch das $Enth{\ddot{u}}llung$ des Anderen, den die System des Neo-liberalismus $verh{\ddot{u}}llt$. Damit der Anderen aufgezeigt wird, machen die verschiedene theatralische Experimente die $B{\ddot{u}}hne$ zu einem leeren Raum, indem sie den $gew{\ddot{o}}hnlichen$ dramatischen Rahmen zu $zerst{\ddot{o}}ren$ versucht. In diesem Raum wird die Vorstellungskraft der Zuschauer erst aktiviert, dadurch die Zuschauer selbst entscheiden $k{\ddot{o}}nnenn$, was sie verstehen $m{\ddot{o}}chten$ und wie sie sich dazu verhalten sollen. All diese Prozesse $m{\ddot{u}}ssen$ die Zuschauer auch als Individuum konstruieren. Die von tradtionellen Theater $getr{\ddot{a}}umte$ Zuschauergemeinschaft, die der Botschaft aus der $B{\ddot{u}}hne$ $gleichm{\ddot{a}}{\ss}ig$ zugestimmt hat, ist daher nicht mehr da. Im heutigen Theater handelt es sich um jeden Zuschauer, der selbst aktiv handelt. Solche Subjekt ist die echte demokratische, die in der heutigen politischen Wissenschaft mehrmals betont wird.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2624-2630
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• 2013

In LED chip packaging, die bonding is a very important process which fixes the LED chip on the lead flame to provide enough strength for the next process. During the process, inspection processes are very important to detect exact locations of dispensed epoxy dots and to determine bonding status of dies whether they are lies at exact positions with sufficient bonding strength. In this study, a useful machine vision based inspection system is proposed for the LED die bonder. In the proposed system, 2 cameras are used for epoxy dot position detection and 2 cameras are sued for die attaching status determination. New vision processing algorithm is proposed, and its efficiency is verified through required field experiments. Measured position error is less than $X:-29{\mu}m$, $Y:-32{\mu}m$ and rotation error:$3^{\circ}$ using proposed vision algorithm. It is concluded that the proposed machine vision based inspection system can be successfully implemented on the developed die bonding system.

• Journal of the Semiconductor & Display Technology
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• v.18 no.3
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• pp.12-18
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• 2019

The protective double layer polymer coatings on silica optical fibers are realized by wet-on-wet liquid coating process and they play an important role in final quality of mass produced optical fibers. This numerical study aims to analyze the effects of secondary coating die design parameters by employing two dimensional axisymmetric model of coating cup and coating die geometry and computational fluid dynamics simulations which include temperature dependent viscosity of polymer coating liquids and viscous dissipation heating. Under high speed fiber drawing conditions and pressurized coating liquid supply, the effects of converging die angle are investigated in order to appreciate the change of coating liquid flow patterns such as flow recirculation zone near coating die as well as primary and secondary coating layer thicknesses. The auxiliary coating die to converging coating die is also tested and the results find that this concept is advantageous in achieving stable double layer coatings on silica glass fiber.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.1
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• pp.34-41
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• 2021

Interventional radiology and minimally invasive surgery both require a precisely shaped microcatheter. Microcatheters are manufactured using polymer extrusion processes with a die and puller. The manufacturing parameters and die geometry greatly influence the profile of the extrudate and designing dies using a trial-and-error process is expensive and requires a lot of time. Therefore, predicting the profile of the extrudate is important for manufacturing microcatheters. This study investigates the effects of die design and geometry on the profile of the extrudate. The profiles of the extrudate are predicted using ANSYS Polyflow with respect to the different die geometries. The outer and inner diameters and wall thickness of the predicted extrudate are compared to those of a target extrudate. The die swell of melt polymer and the effect of the pulling are both examined. Optimized die designs are suggested for manufacturing the target extrudate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1307-1311
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• 2004

This paper deals with an automated computer-aided process planning and die design system by which designer can determine operation sequences even if they have a little experience in process planning and die design for axisymmetric products. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. They can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution on the level of the required forming loads by controlling the forming ratios. Especially in die design module an optimal design technique and horizontal split die were investigated for determining appropriate dimensions of components of multi-former die set. It is constructed that the proposed method can be beneficial for improving the tool life of die set at practice.