• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1140-1144
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• 2005

A plastic-based CE (capillary electrophoresis) microchip was fabricated by hot embossing process. A Si mold was made by wet etching process and a PMMA wafer was cut off from 1mm thick PMMA sheet. A micro-channel structure on PMMA substrate was produced by hot embossing process using the Si mold and the PMMA wafer. A vacuum assisted thermal bonding procedure was employed to seal an imprinted PMMA wafer and a blank PMMA wafer. The results of microscopic cross sectional images showed dimensions of channels were well preserved during thermal bonding process. In our procedure, the deformation amount of bonding process was below 1%. The entire fabrication process may be very useful for plastic based microchip systems.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.277-281
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• 1988

Although widely used in external beam treatment planning, computed tomography scans are infrequent in incranial tumors by implanting of Radioactive isotope. This incranial brachytherapy has only become possible by using CT scans and stereotaxic operation methods. The coincidence of single source and tumor axes in brachytherapy is very important to determine the therapeutic dosages. Eventhough using the CT scan, according to spatial location of tumor tying, the section of tumor will be seen enlargement, cause the tumor will be cut off with slight angle to its axes. Correct analysis of tumor size from source is required for rotated axes in analytical geometry.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.431-443
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• 2013

Sulfur content of diesel fuel has been cut down to under 10 ppm ULSD (ultra low sulfur diesel) level by environmental regulation with the aim of reducing exhaust emissions. This review discusses the methods and principles of sulfur reduction in diesel and presents an overview of new approaches for ultra-deep desulfurization. The deep HDS (hydrodesulfurization) problems of diesel streams is exacerbated by the inhibiting effect of co-existing aromatics, nitrogen compounds and $H_2S$. The new approaches to deep desulfurization includes non-HDS type processing schemes such as adsorptive, extractive and oxidative desulfurization.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.137-137
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• 2015

The purposed of this work was to observe hydroxyapatite precipitation phenomena on micro-pore formed Ti-Nb alloy by PEO technique. The Ti-30Nb and Ti-30Ta alloys were remelted at least ten times in order to avoid inhomogeneity, and then cylindrical specimens (diameter 10 mm, thickness 4 mm) were cut by using laser from cast ingots of the Ti alloys. Heat treatment was carried out at $1050^{\circ}C$ for 2 h for homogenization in argon atmosphere. The morphologic change of the alloys were examined by X-ray diffractometer (XRD) and field emission scanning electron microscopy (FE-SEM).

• Korean Journal of Veterinary Service
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• v.37 no.4
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• pp.313-317
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• 2014

A bitch was presented for investigation of the mass in left 5th mammary gland. The partial mastectomy was performed and submitted for the histopathological diagnosis. The mammary mass was firm and white colored. The cut surface was separated with several lobules and developed vessels. The central area of the mass formed the cavity filled with inflammatory exudates. The dominant component of the tumor was the bundles of spindle-shaped cells. Some tumor cells possessed atypical nuclei and were arranged in a solid nest. Cysts were microscopically composed of hemorrhage, necrosis, and exudates, partially surrounded by tumor cells and granulation tissues. Histopathologically, the mammary mass revealed spindle cell carcinoma. The bitch made a complete recovery following the mastectomy. This case was a rare mammary spindle cell carcinoma in a dog.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.255-257
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• 2004

This paper was studied electromagnetic field distribution and damping of PD(Partial Discharge) signal in GIS(Gas Insulated Switchgear). Cut-off frequency of electromagnetic wave propagation modes were computed, electromagnetic field distribution of propagation modes in GIS by FEM(Finite Element Method) were simulated and simulated damping characteristic of electromagnetic waves in GIS by EMTP(Electromagnetic Transient Program) when generated PD pulse. Frequency band of $TE_{mn}/TM_{mn}$ modes were determinated by simulation results of electromagnetic field distribution and were discussed optimal position of UHF sensor from this results. Equivalent circuit was used to simulate signal damping of PD pulse in GIS by EMTP and compared with measured results in laboratory of KERI.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.61-67
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• 2017

Research into the selection of suitable materials and the development of fast processing methods for press die manufacturing is absolutely necessary to reduce the production time and cost. In particular, knowledge of its heat properties must be considered whendeveloping a long press die. Generally, as the main component materials of press dies, Cr, W low alloy tool steel, high carbon-high chrome steel, high speed steel, etc., are used as thetooling steel for the cold die. Machine tools and wire-cut electric discharge machining are mainly used for processing the press die parts. There are many differences in the machining time and life cycle of die parts depending on the machining process. The parts produced by milling and grinding have a high manufacturing time and cost with a long life cycle, while thosemade by milling and wire-cut discharge machining have areduced manufacturing time and cost,whereastheir die life cycle is reduced. Therefore, in this study, we will discuss amethod of improving the life cycle of the die parts by using heat treatment as a processing method that reduces the manufacturing time and cost. SEM, EDS analysis and the surface roughness analysis of the surface and center of the workpiece are used for analyzing the specimens produced by three machining methods, viz. milling - grinding, milling - wire cut discharge, and milling - wire cut discharge - heat treatment. A method of making die parts having the same life cycle as those produced by milling - grinding is developed with the milling - wire cut discharge - high temperature tempering method.

• Journal of Fashion Business
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• v.12 no.4
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• pp.28-45
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• 2008

The purpose of this study is to diagnose actual condition of preference of hair-styling, hair-styling techniques, management, grasping a consumer's consciousness, etc with women living in a city. The survey was gotten to a feminine customer who visited the ten of beauty-shops in shopping center. And statistical data about the actual condition of hair-styling preference realities, hair-styling method and style management was entered into the SPSS statistics analysis system. In brief, be as follows by the results of study. There showed significant difference that noted in hair-style information and basis alternative a beauty salon, there were able to know people whose age is from 20's to 40's got mainly an influence of public media very much and from 40's to 50's got mainly an influence of people around them. Basis alternative of a beauty salon showed significant difference to follow age categories. It appeared that introducing from people around them have a effect on the 20's and 30's, and 40's got an influence of convenience of traffic, and 50's got mainly the shortest distance. In an attitude toward a hair style, especially toward hair cut, a case to do hair cut was most a lot of in own selections, and its result was independent of age categories. The reason that wants to give a chance was most a lot of thinking without an age. Preference length of hair cut showed a significant difference according to age. In permanent section, own selections appeared most regardless of age. And in the permanent motive, also, to have a change appeared most regardless of age. And people had a preference natural to role up to setting regardless of age in permanent wave. In hair color section, women whose age is 20's, 30's, 40's had a motive for a change, on the other hand, 50's and their senior had a motive for a gray hair. Women of all over the age almost knew a fashion color, and they had a preference brown color. In a preference way along a hair color kind, there was a significant difference according to age, also. 20's and 30's did mainly 'semi-permanent coating' and 40's and 50's did mainly 'permanent hair color'. In a attitude about a hair-style management, the more age is young, the more a period is long term. And the more age is old, the more the outlay for price of cut is expensive. But, on the contrary, permanent price showed that the more age is young, the more the outlay for price of permanent is expensive. In hair color, the more age is old, the more a period is short and the more price is low.

• Journal of the Korean Geotechnical Society
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• v.33 no.11
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• pp.73-82
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• 2017

Recently, offshore bucket cut-off walls were developed to solve several problems in conventional offshore cut-off walls. In this study, a numerical analysis was carried out to investigate the seepage stability of offshore bucket cut-off walls. The ground was assumed as uniform homogeneous sand and steady state flow conditions were applied. The flow condition was compared among 2-dimensional flow (2-D), 2-dimensional concentrated flow (2-DC), and axisymmetric flow. The analysis results showed that the seepage velocities in axisymmetric flow were about 1.5 and 2 times larger than those of 2-DC and 2-D flow conditions, respectively. Thereafter, the axisymmetric flow condition was applied because the seepage flow was concentrated toward the center of the circular-shaped wall. A parametric study was performed varying bucket radius, penetration depth, total head difference between in and outside of the wall. The exit gradient, which used for the calculation of piping stability, decreased with increase of the penetration depth and bucket radius. Design charts were proposed to estimate the factor of safety and the exit gradient at various analysis conditions. Finally, the design equation was proposed to calculate the exit gradient for the preliminary design of the bucket cut-off wall.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.49-54
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• 2006

Purpose : To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. Materials and Methods : One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant differences between the direct measurements and those using the 3D images (p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. Conclusion : The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissues thickness more easily in forensic science and anthropology.