• International Journal of Precision Engineering and Manufacturing
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• v.7 no.3
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• pp.56-59
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• 2006

UV laser micromachining is generally used to create microstructures for micro-products through a sequence of lithography-based photo-patterning steps. However, the micromachining process is not suitable for rapid realization of complex 3D micro-products because it depends on worker experience. In addition, the cost and time required to make many masks are excessive. In this paper, a more effective and rapid micro-manufacturing process, which was developed based on laser micromachining, is proposed for fabricating micro-products directly using UV laser ablation and phase-change filling. The filling process is useful for holding the micro-products during the ablation step. The proposed rapid micro-manufacturing process was demonstrated experimentally by fabricating 3D micro-products from functional UV-sensitive polymers using 3D CAD data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.26-29
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• 2003

UV laser micromachining are generally used to create microstructures for micro product through a sequence of lithography-based photopatterning steps. However, the micromachining process is not suitable for the rapid realization of complex microscale 3D product because it depends on worker experiences, excessive cost and time to make many masks. In this paper, the more effective micro rapid manufacturing process, which is developed upon the base of laser micromachining. is proposed to fabricate micro products directly using UV laser ablation and phase change filling. The filling process is useful to hold the micro product during the next ablation step. The proposed micro rapid manufacturing process is also proven experimentally that enables to fabricate the 3D microscale products of UV sensitive polymer from 3D CAD data to functional micro parts.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.11 s.176
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• pp.196-201
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• 2005

UV laser micromachining are generally used to create microstructures for micro product through a sequence of lithography-based photopatterning steps. However, the micromachining process is not suitable for the rapid realization of complex 3D micro product because it depends on worker experiences, excessive cost and time to make many masks. In this paper, the more effective micro rapid manufacturing process, which is developed upon the base of laser micromachining, is proposed to fabricate micro products directly using UV laser ablation and phase change filling. The filling process is useful to hold the micro product during the next ablation step. The proposed micro rapid manufacturing process is also proven experimentally that enables to fabricate the 3D micro products of UV sensitive polymer from 3D CAD data to functional micro parts.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.171-174
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• 2004

Superalloys with many strengthening alloying elements are frequently used in powder form to alleviate harmful effects of alloy segregation. HIP (hot isostatic pressing) and DB (diffusion bonding) as a form of solid-state bonding process is often used to make turbine components, such as integrated turbine rotors. HIP/DB process requires many technical overcomes related to dimensional changes as well as microstructural control. In this research, HIP/DB process for nickel base superalloys, Udimet 720, were investigated with a view to control the dimensional change during the consolidation process. Simple disc-shaped cans were used to select the conceptual die design for the control of the dimensional change especially in radial direction. The change in the shape of consolidated shape was investigated using commercial FE code with constitutive equations for low temperature plasticity and creep deformation.

• Journal of the Semiconductor & Display Technology
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• v.19 no.2
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• pp.16-21
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• 2020

How accurately reproducible energy is delivered to the wafer in the process of making thin films using PE-CVD (Plasma enhanced chemical vapor deposition) during the semiconductor process. This is the most important technique, and most of the reaction on the wafer surface is made by thermal energy. In this study, we studied the method of monitoring the change of thermal energy transferred to the wafer surface by monitoring the temperature change according to the change of the thin film formed on the showerhead facing the wafer. Through this research, we could confirm the monitoring of wafer thin-film which is changed due to abnormal operation and accumulation of equipment, and we can expect improvement of semiconductor quality and yield through process reproducibility and equipment status by real-time monitoring of problem of deposition process equipment performance.

• Korean Journal of Metals and Materials
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• v.49 no.11
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• pp.823-830
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• 2011

Structural change in an amorphous alloy was measured by applying a load below the global yield stregth at ambient temperatures. It was observed that the magnitude of the apparent structural change occuring in the amorphous alloy is determined by the compatative relationship between the stress-induced disordering process and the thermally-activated relaxation process. Structural disorder was observed to take place even at a stress well below the global yield, and the degree of the disorder was increased abruptly at the earlier stage of loading and saturated with time. In the mean time, unlike the previous belief, the relaxation process was observed to occur even at embient temperatures, and the degree of the relaxation was observed to increase linearly with time. The analytical equation predicting the structural change was proposed.

• Journal of Internet Computing and Services
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• v.5 no.4
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• pp.11-22
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• 2004

Works that improve the process and notify the improved process, the product and the change of tasks to all users are essential in achieving project. Existent project management tools support the definition and the change of project activities, and configuration management tools support version check, workspace management. build management. etc. It costs too much to buy each tool. as well as, it is burdensome to learn usage for various tools. Therefore the web-based integrated tool is proposed to manage the process and artifacts at a time in this paper. The proposed tool defines component based development process model. and achieves recording of process progression, processing the request of change, reporting the progression of each task, product registering and change, version recording, artifact or form search, etc. using ebXML. Furthermore, the stakeholders get the systematic management and standardization by sharing information that are necessary in process achievement and configuration management in distributed environment using the integrated management tool.

• Research in Community and Public Health Nursing
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• v.23 no.3
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• pp.316-326
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• 2012

Purpose: This study was to identify the factors associated with stages of exercise behavior change of residents in a community on the basis of the Transtheoretical Model. Methods: Data were collected from 520 residents of a community using a self-report questionnaire. The survey variables comprised the stages of exercise behavior change, the process of change, decisional balance and self efficacy. Results: There were significant differences in the process of change, decisional balance and self efficacy by the stages of exercise behavior change. The factors associated with transition from pre-contemplation to contemplation were consciousness raising and self efficacy; regarding those from contemplation to preparation, cons of the decisional balance and social liberation; regarding those from preparation to action, dramatic relief and counter conditioning; regarding that from action to maintenance, cons of the decisional balance. Conclusion: TTM would be applicable to explain the exercise behavior of some residents in a community, which suggested that the programs for improving exercise behavior of residents in a community need to be developed.

• Journal of the Korean Society of Visualization
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• v.21 no.2
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• pp.63-71
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• 2023

Energy storage and distribution technologies are emerging as important factors as research on renewable energy continues. Analyzing the thermal flow of phase change material inside a latent heat storage device and to predict the phase change time is an important part for improvement of thermal performance. However, most of the current research is based on the trial-and-error experimental investigation to measure the phase change time. Therefore, in this study, a can-type phase change material container was designed, and the numerical method for analyzing the thermal flow of phase change material was established and validated. The error rate of the phase change time between the numerical and experimental results was within 5%, which proves its reliability. As a result, the phase change finishing times were found to be 78 minutes with inlet fluid temperature of 80℃ during charging process, and 126 minutes with inlet fluid temperature of 9℃ during discharging process.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.4
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• pp.113-134
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• 1994

A radial basis hybrid neural network (RHNN) is presented for an on-line detection of machine condition change. Two-phase modeling by RHNN is designed for describing a machine condition process and for predicting future signal. A moving block procedure is also designed for detecting a process change. A fast on-line learning algorithm, the recursive least square estimation, is introduced. Experimental results showed the RHNN could be utilized efficiently for on-line machine condition monitoring.