• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1732-1734
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• 1999

In order to study the fabricating condition of phosphor layers of thin film EL devices, some discharge characteristics with several targets in the parallel-plate magnetron sputtering system will be studied. Plasma parameters, such as electron density and temperature, are also studied since they may be considered as one of the very important factors of fabricating condition of thin film EL device.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.11
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• pp.1053-1058
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• 2007

Micro-EDM technology (or the manufacture of miniature parts is used to make a micro hole. Two electrode shaping methods, mechanical electrode grinding and WEDG technique, have been studied. In this study, an electrode shaping method by using previously machined hole is introduced in order to obtain an optimal hole-making condition. Key factors such as applied voltage, capacitance, feedrate, and hole-dimension have an influence on the fabricating error of electrode shaping, which are taper ratio of a hole, electrode form accuracy, and electrode surface. Therefore, we try to investigate the optimal fabricating of electrode shaping from various experiments. Results from experiments, it was able to minimize the electrode fabricating error as voltage increases, and also applied feedrate and capacitance decreases.

• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.66-71
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• 2011

The flexural strength of $MoSi_2$ based composites reinforced with Nb sheets has been investigated, based on the detailed examination of their microstructure and fractured surface. Both sintered density and porosity of Nb/$MoSi_2$ composites were also examined. Nb/$MoSi_2$ composites were fabricated by different conditions such as temperature, applied pressure and its holding time, using a hot-press device. The volume fraction of Nb sheet in this composite system was fixed as 10%. The characterization of Nb/$MoSi_2$ composites were investigated by means of optical microscopy, scanning electron microscope and three point bending test. Nb/$MoSi_2$ composites represented a dense morphology at the interfacial region, accompanying the creation of two types of reaction layer by the chemical reaction of Nb and $MoSi_2$. Nb/$MoSi_2$ composites possessed an excellent density at the fabricating temperature of $1350^{\circ}C$, corresponded to about 95% of theoretical density. The flexural strength of Nb/$MoSi_2$ romposites were greatly affected by the pressure holding time at the same fabricating temperature, owing to the large suppression of porosity in the microstructure. Especially, Nb/$MoSi_2$ composites represented a good flexural strength of about 310 MPa at the fabricating condition of $1350^{\circ}C$, 30MPa and 60min, accompanying the pseudo-ductile fracture behavior by the deformation of Nb sheet and the interfacial delamination.

• Journal of the Korea Safety Management & Science
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• v.8 no.6
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• pp.13-27
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• 2006

The goal of this study is to propose the effective way of finding injurious factors and making improved plan that prevents the workers against musculoskeletal disorders at a semi-finished medical product fabricating company A questionnaire and an ergonomic assessment method were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an analysis of working postures and a quantitative assessment on various processes were performed to find out harmful factors of workplace. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. It can be concluded that the method and process described in this paper could be helpful for diagnosing the musculoskeletal disorders and making improvement plans to the company with similar working conditions and process.

• Journal of the Semiconductor & Display Technology
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• v.2 no.1
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• pp.21-24
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• 2003

Sludged silicon powders that are generated during silicon ingot slicing process have potential usage as silicon source in fabricating silicon carbide powders by adding carbon. A thermodynamic calculation is performed to consider a plausible formation condition for the silicon carbide powders. A thin silicon oxide layer around silicon powder is sufficient to supply equilibrium oxygen partial pressure at the formation temperature($1400^{\circ}C$) of the silicon carbide in the Si-C-O ternary system. Formation of silicon carbide by using the sludged silicon powders is more efficient than by using silicon oxide powders.

• Rapid Communication in Photoscience
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• v.2 no.3
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• pp.79-81
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• 2013

A novel method of fabricating polythiophene-gold nanoparticle composite film electrodes for photoelectric conversion is demonstrated. The method includes electrodeposition of gold and electropolymerization of 2,2'-bithiophene onto an indium-tin-oxide (ITO) electrode. First, electrodeposition of gold onto the ITO electrode was carried out with various repetition times of pulsed applied potential (0.25 s at -2.0 V vs. Ag/AgCl) in an aqueous solution of $HAuCl_4$. Significant progress of the number density of deposited gold nanoparticles was confirmed from scanning electron micrographs, from 4 (1 time) to 25% (15 times). Next, electropolymerization of 2,2'-bithiophene onto the above ITO electrode was performed under controlled charge condition (+1.4 V vs. Ag wire, 15 $mC/cm^2$). Structural characterization of as-fabricated films were carried out by spectroscopic and electron micrographic methods. Photocurrent responses from the sample film electrodes were investigated in the presence of electron acceptors (methyl viologen and oxygen). Photocurrent intensities increased with increasing the density of deposited gold nanoparticles up to ~10%, and tended to decrease above it. It suggests that the surplus gold nanoparticles exhibit quenching effects rather than enhancement effects based on localized electric fields induced by surface plasmon resonance of the deposited gold nanoparticles.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.177-184
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• 2001

C3M(chemical mechanical micro machining) is applied for diminishing the size of burr and fabricating the massless patterning for aluminium wafer(thickness of 1${\mu}m$). It is difficult to perform the micro size machining with the radically increased shear stress. While the miniaturization and function-orientation of parts has been needed in the many field such as electronics, optics and medicine. etc., it is not enough to satisfy the industry needs in the machining technology. In this paper feasibility test of diminishing burr and fabricating maskless pattern was experimented and analyzed. In the experiment oxide layer was farmed on the aluminium with chemical reaction by ${HNO_3}$(10wt%), then the surface was grooved with tungsten carbide tool for the different condition such as the load and fred rate. The result was compared with the conventional machining to show the improvement of C3M with SEM for burr diminish and XPS for atomic existence, AFM for more precise image.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.36-42
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• 2021

Even though implant overdentures are preferentially recommended to mandibular edentulous patients, many patients may select conventional complete dentures due to cost and general condition. Proper retention and stability of conventional complete dentures in patients with severe alveolar bone resorption is difficult to achieve. To overcome the limitations, mandibular suction dentures with the closed mouth impression technique have been used. However, the previous technique requires the Frame cut back tray, the Centric tray, and the Gnathometer M. This article introduces a technique for fabricating a mandibular suction denture with common dental materials.

• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.49-56
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• 1999

Welding is a reliable process and is mainly adopted for fabricating heavy structures. Recently, transverse cracks in the weld metal is serious problem, and they affect cost, efficiency, safety and joint reliability for various welded structures. In this view of point, this study investigated the potential factors for weld metal transverse crack. The main results obtained are as follows; 1) The content of diffusible hydrogen in the commercial flux cored are welding wire was remarkable change by manufacturer. 2) The diffusible hydrogen content was thd main factor for weld metal transverse cracks. 3) Weld metal was immune to transverse cracking under the condition of low diffusible hydrogen content of high restraint condition. 4) The factors for weld metal transverse crack would be the content of diffusible hydrogen and restraint of weld joint.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.649-654
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• 2002

In recent days the more use of CFRP composite is in the airplane, automobile, and sport goods , etc., the more necessity of research on it in this engineering. In this research, the CFRP composite specimen are fabricated by 48 CFRP plies with 8 orientation angles, and the specimens are drilled with 3 tools. The results are analyzed with consideration of cutting force, type of tools and fabrication condition. The specimens with each drilling conditions are also investigated with SEM. The optimal drilling conditions such as drill types and cutting fence with respect to the fabricating condition are studied.