• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.924-929
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• 2007

This paper introduces a simulation model regarding the process analysis of a LED assembly process. The objective of the simulation model is to evaluate the performance of various design aspects of process alternatives. To develop the simulation model, a time study is performed for each process. Next, by using ARENA, a simulation model is conducted based on the process analysis and the line balancing methodology. We found out several problems for the assembly process, and then suggest several alternatives to improve the system.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.182-187
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• 2004

As it is difficult to construct a micro-fluidic system composed of micro-mixers, micro-channels and/or micro-chambers in a single process, an assembly process is typically used. The assembling and bonding of micro-parts, however, introduces other problems. In this work, a virtual assembly process was developed that can be used to design various micro-systems before actual fabrication commences. In the process, the information required for the micro-stereolithography process is generated automatically. Consequently, complex micro-fluidic systems can be fabricated in a single process, thereby avoiding the need fur additional assembly or bonding processes. Using the developed process, several examples were fabricated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1509-1521
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• 2011

WfMC, which is one of the international standardization organizations leading the business process and workflow technologies, has been officially released the BPAF1.0 that is a standard format to record process instances' event logs according as the business process intelligence mining technologies have recently issued in the business process and workflow literature. The business process mining technologies consist of two groups of algorithms and their analysis techniques; one is to rediscover flow-oriented process-intelligence, such as control-flow, data-flow, role-flow, and actor-flow intelligence, from process instances' event logs, and the other has something to do with rediscovering relation-oriented process-intelligence like process-driven social networks and process-driven affiliation networks from the event logs. The current standardized format of BPAF1.0 aims at only supporting the control-flow oriented process-intelligence mining techniques, and so it is unable to properly support the relation-oriented process-intelligence mining techniques. Therefore, this paper tries to extend the BPAF1.0 so as to reasonably support the relation-oriented process-intelligence mining techniques, and the extended BPAF is termed BPAF2.0. Particularly, we have a plan to standardize the extended BPAF2.0 as not only the national standard specifications through the e-Business project group of TTA, but also the international standard specifications of WfMC.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.65-70
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• 2021

In this study, interfacial properties and mechanical properties of joints were reported after Cu pads finished with organic solderability preservative (OSP) on flame retardant-4 (FR-4) printed circuit board (PCB) and electronic components were joined with a Sn-57Bi-1Ag solder paste by using a laser bonding process. The laser bonding process was performed under various bonding conditions with changing a laser power and a bonding time and effects of bonding conditions on interfacial and mechanical properties of joints were analyzed. In order to apply for industry, properties of bonding joints using a reflow bonding process which are widely used were compared. When the laser bonding process were performed, we observed that Cu₆Sn₅ intermetallic compounds (IMCs) were fully formed at the interface although the bonding times were very short about 2 and 3 s. Furthermore, void formations of the joints by using the laser bonding process were suppressed at the joints with comparing to the reflow bonding process and shear strengths of bonding joints were higher than that by using the reflow bonding process. Therefore, in spite of a very short bonding time, it is expected that joints will be stably formed and have a high mechanical strength by using the laser bonding process.

• 대한공업교육학회지
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• v.40 no.2
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• pp.196-215
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• 2015

The purpose of this study was to develop the instructional process plan and performance assessment instrument to do problem-solving activity for 'Energy and Transportation Technology' unit at the subject 'Technology-Home Economics' in middle school. This study was conducted by the following these stage. First, it was documents research and analysis of the 'Energy and Transportation Technology' unit. Second, topics for transportation technology hands-on and problem-solving activity were selected, and the organized for designed instructional process plan and performance assessment instrument related transportation technology in the development step. Third, developed instructional process plan and performance assessment instrument were conducted in order to amend and improved by expert and have gone through the field test for further improvement. The theme of transportation technology for hand-on and problem-solving activity was 'Created a hovercraft', and were consist of instructional process plan for 8 class period and performance assessment instrument in 4 type of observation, assessment finished, portfolios and student self-assessment.

• Journal of Korea Technology Innovation Society
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• v.5 no.2
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• pp.212-227
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• 2002

This study reviews the institutional frameworks of Open Source software and develops the stylized facts of Open Source software innovation. Open Source software have to solve two difficult problems for encouraging innovation. First, the source code of Open Source software program should be open and freely distributed and it is very difficult for developers to appropriate the results of their investments. Second, as Open Source software development process is characterized by the participation of communities of developers, it is not easy to coordinate and manipulate the development process. These difficulties of developing Open Source Software have been solved by the particular incentive schemes and coordinating mechanisms. This study reviews the study on the motivation of Open Source software development and the mechanisms which coordinate innovation process of Open Source software with peer review and meritocracy, and how these characteristics promote innovation in Open Source software communities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.769-776
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• 2006

It is important for evaluation execution about technology development. And it is necessary to settle together with technology development activity to evaluation execution. Purpose of this paper is to decide request for proposal and suitable to proposed enterprise contents about technology part in performance. Therefore let estimate the data about it. So suitable enterprise is selected through applying evaluation data to TEPM(Technology Evaluation Process Model).

• Design & Manufacturing
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• v.12 no.3
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• pp.42-47
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• 2018

Recently, in the surge of global environmental issues, there has been a great attention to lightweight materials in purpose of saving energy. Magnesium alloys not only have low specific gravity, and superb specific stiffness, but are also excellent in blocking vibrations and electromagnetic waves. So demand for this material is getting bigger rapidly throughout the industry. In this study, we examined the improvement of formability of magnesium alloy AZ31 material in warm working. Drawing, bending and shearing process were carried out by varying the forming temperature and the forming speed, and the influence of the variables on each process was studied. In the experiments, the high forming temperature and low forming speed results in high formability in the drawing process and the bending process. In the shearing process, as the forming temperature increases, the length of the fracture decreases.

• Current Photovoltaic Research
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• v.7 no.2
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• pp.51-54
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• 2019

The high density module (HDM) has advantages for its larger active area and smaller current density. This new way of making a photovoltaic (PV) module method has benefit for increasing module power with the same installed area. Because HDM consisted with serially connected PV strings, loss of strings during the fabrication process can increase the overall production cost.1-2 This study investigates the rework conditions of the shingled strings with electrically conductive adhesives (ECA). By heating the electrically connected area of a fabricated string, cured area become soft and a string can be detached for the rework process. After rework process, a refabricated string showed 5~10% increased output power compared to before rework process and reached to the 90~95% output power compare to the undamaged strings.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.796-805
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• 2009

In this paper, a fabrication process for PZT preform of 1-3 type piezo-composite were studied using powder injection molding (PIM). The viscosity and the Pressure-Volume-Temperature (PVT) characteristics of the fabricated PZT feedstock were analyzed. The filling patterns, pressure, temperature distributions, and forming defects of the preform were analyzed with 3D TIMON commercial packages during PIM process. Also the fabrication conditions and the delivery system of the preform were optimized during the entire PIM process. Based on the simulated results, the preform having uniform distributions of the PZT rod was fabricated with the PIM process.