• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.53-58
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• 2006

This study deals with the method of post-processing in the automatic tool path generation for 5-axis NC machining. The 5-axis NC machining cannot only cope with the manufacturing of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. Thus 5-axis NC machining has been used for aircraft parts, mold and die as well as for complicated shapes such as impeller, propeller and rotor. However, most of the present CAM systems for 5-axis NC machining have limited functions in terms of tool collision, machine limits and post-processing. Especially 5-axis machine configurations are various according to the method which the rotational axes are adapted with the table and spindle. For that reason, In many cases the optimal numerical control (NC) data cannot be obtained or considerable time is consumed. To solve this problem, we applied a general post-processor for 5-axis NC machining. The validity of this post-processor should be experimentally confirmed by successfully milling to a helix shaped workpiece.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.370-374
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• 2005

This study deals with the method of post-processing in the automatic tool path generation for 5-axis NC machining. The 5-axis NC machining cannot only cope with the manufacturing of complicated shapes, but also offers numerous advantages such as reasonable tool employment, great reduction of set-up process and so on. Thus 5-axis NC machining has been used fur aircraft parts, mold and die as well as for complicated shapes such as impeller, propeller and rotor. However, most of the present CAM systems for 5-axis NC machining have limited functions in terms of tool collision, machine limits and post-processing. Especially 5-axis machine configurations are various according to the method which the rotational axes are adapted with the table and spindle. For that reason, in many cases the optimal numerical control (NC) data cannot be obtained or considerable time is consumed. To solve this problem, we applied a general post-processor fur 5-axis NC machining. The validity of this post-processor should be experimentally confirmed by successfully milling to a helix shaped workpiece.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.118-126
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• 2000

Die-casting burr to casting process is removed by post-process for assembly and quality control of product. Though robot has been widely used for deburring job before. CNC exclusive machine is currently developed for high power, high speed machining and quick tool change. Deburring tool path with complex 3D curve type is defined to make out deburring NC program. But there is no efficient method to define it currently used methods with teaching probe on machine. In this study the efficient method to make out deburring NC program is developed. 5-axis digitizing machine is used to receive data of deburring path. And the post process for NC program generation is developed in consideration of the machining conditions. The developed system is not dependent on the skill of operator and has the advantage to maintain the flexibility of job to modify NC program due to the wear of tool and aging of the die casting.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.70-76
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• 1999

Recently most of researches for deep drawing process using sheet metal have been performed on the formability of axisymmetric shape but there have not been any concrete reports on the formability of non-axisymmetric shape In addition the conventional shape radius of the punch and die has been determined by the trying-and-error using industrial experimence and post processing test and only approximate shape radius of the punch and die has been determined by the trying-and-error using industrial experience and post processing test and only approximate shape radius of the punch and die has been present So in this study the optimal shape radius of the punch and die in deep drawing process with biaxisymmetric blank shape would be proposed. Through the deep drawing experiment it is found that in order to obtain the optimal products especially shape radius of the punch and die in all processes is very important.

• Journal of Families and Better Life
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• v.25 no.1 s.85
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• pp.183-207
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• 2007

The purpose of this study was to improve the understanding of the essential experience of Separated Families in South and North Korea in a socio-cultural context and to explore their post-separation adjustment process from the perspective of the families. Major findings in this study are summarized as follows. First, 'han' was the central phenomenon that the participants experienced following their separation. Second, the core issue in the process of post-separation adjustment was 'accepting the separation and rearrangement of reality for reunion', and over time the participants went through four stages in their adjustment process: the stage of being overwhelmed, the stage of conflict, the stage of awareness, and the stage of acceptance. Third, the main factors affecting the participants' adjustment were supportive systems, available resources(individual variables) and interaction with other separated families. fourth, four types were observed in the typology of adjustment and reunion of the participants.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.43-44
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• 2005

SU-8 is a epoxy based photoresist designed for MEMS applications, where a thick, chemically and thermally stable image is desired. But SU-8 has proven to be very sensitive to variation in processing variables and hence difficult to use in the fabrication of useful structures. In this paper, negative SU-8 photoresist processed has been characterized in terms of delamination. Based on a full factorial designed experiment. Employing the design of experiment (DOE), a process parameter is established, and analyzing of full factional design is generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.121-121
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• 2018

Copper is a promising electronic material due to low cost and high electrical conductivity. However, the oxidation problem in an ambient condition makes a crucial issue in practical applications. In here, we developed a simple and cost-effective Cu patterning method on a flexible PET film by combining a solution processable Cu nanoparticle patterning and a low temperature post-processing using acetic acid treatment, laser sintering process and acid-assisted laser sintering process. Acid-assisted laser sintering processed Cu electrode showed superior characteristics in electrical, mechanical and chemical stability over other post-processing methods. Finally, the Cu electrode was applied to the flexible electronics applications such as flexible and transparent heaters and touch screen panels.

• Journal of information and communication convergence engineering
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• v.3 no.4
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• pp.191-194
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• 2005

SU-8 is a epoxy based photoresist designed for MEMS applications, where a thick, chemically and thermally stable image are desired. However SU-8 has proven to be very sensitive to variation in processing variables and hence difficult to use in the fabrication of useful structures. In this paper, negative SU-8 photoresist processed has been characterized in terms of delamination, based on a full factorial designed experiment. Employing the design of experiment (DOE), a process parameter is established, and analyzing of full factorial design is generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.22-27
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• 2020

In this paper, we study the methodology to improve productivity and transportation efficiency simultaneously in the manufacturing environment of injection plants which has multiple injection machines arranged in parallel. In general, the post-processes such as finishing are continuously arranged in the injection machine located in the lower level of the injection plants, and one or two workers in charge of post-processing are always arranged. Therefore injection plants have low productivity due to post-processing and the front of the injection machine is very crowded due to various logistics flows. In this paper, we propose the designing methodology of conveyor structure for integrating the post-processes arranged at each injection machine and transporting the injection products to the integrated post-process automatically. Specifically, we propose the models for computing the number of conveyor units into the integrated processes, and for finding the optimal combinations to connect each machines and the conveyors. The proposed model is for the total productivity improvement, which are productivity and transportation efficiency. By applying the proposed model to companies that produce injection parts used for the home appliances, we verify the applicability and the effect of improving productivity and transportation efficiency, which more than 40%.

• Journal of the Korean Ceramic Society
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• v.43 no.2 s.285
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• pp.106-113
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• 2006

PMN-PZT films with thickness of $5\;{\mu}m$ were deposited on $Pt/Ti/SiO_2/Si$ substrate at room temperature using aerosol deposition process. The films showed fairly dense microstructure without any crack. XRD and TEM analysis revealed that the films consisted of randomly oriented nanocrystalline and amorphous phases. Post-annealing process was employed to induce crystallization and grain growth of the as-deposited films and to improve the electrical properties. The annealed film showed markedly improved electrical properties in comparison with as-deposited film. The film after annealing at $700^{\circ}C$ for 1h exhibited the best electrical properties. Dielectric constant $(\varepsilon_r)$, remanent polarization $(P_r)$ and piezoelectric constant $(d_{33})$ were 1050, $13\;{\mu}C/cm^2$ and 120 pC/N, respectively.