• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.25-25
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• 2018

Electron beam melting (EBM) is one of powder based additive manufacturing technology used to produce parts for high geometrical complexity and directly with three-dimensional computer aided design (CAD) model. It is kind of the most promising methods with additive manufacturing for a wide range of medical applications, such as orthopedic, dental implant, and etc. This research has been investigated the microstructure and mechanical properties of as fabricated and hot iso-static pressing (HIP) processed specimens, which are made by an Arcam A1 EBM system. The Ti-6Al-4V titanium alloy powder was used as a material for the 3 dimensional printing specimens. Mechanical properties were conducted with EBM manufacturing and computer numerical control (CNC) machining specimens, respectively. Surface morphological analysis was conducted by scanning electron microscopy (SEM) for their surface, dissected plan, and fractured surface after tensile test. The mechanical properties were included tensile stress-strain and nano-indentation test as a analysis level between nano and macro. As following highlighted results, the stress-strain curves on elastic region were almost similar between as fabricated and HIP processed while the ductile (plastic deformed region) properties were higher with HIP than that of as fabricated processed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1217-1223
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• 2003

Nerve gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas is dimethyl methyl phosphonate(C$_3$ $H_{9}$ $O_3$P, DMMP) that is simulant gas of nerve gas. Sensing materials were Sn $O_2$ added a-Al$_2$ $O_3$ with 0∼20wt.% and were physically mixed each material. They were deposited by screen printing method on alumina substrate. The sensor device was consisted of sensing electrode with interdigit(IDT) type in front and a heater in back side. Total size of device was 7${\times}$10${\times}$0.6㎣. Crystallite size & phase identification and morphology of fabricated Sn $O_2$ powders were analyzed by X-ray diffraction and by a scanning electron microscope, respectively. Fabricated sensor was measured as flow type and resistance change of sensing material was monitored as real time using LabVIEW program. The best sensitivity was 75% at adding 4wt.% $\alpha$-Al$_2$ $O_3$, operating temperature 30$0^{\circ}C$ to DMMP 0.5ppm. Response and recovery time were about 1 and 3min., respectively. Repetition measurement was very good with $\pm$3％ in full scale.TEX>$\pm$3％ in full scale.

• Korean Journal of Acupuncture
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• v.22 no.2
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• pp.127-149
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• 2005

This study is designed to investigate the method of manufacturing herbal acupuncture through literature of oriental medicine. The findings of this study are as follows; 1. The methods of manufacturing herbal acupuncture go through the process of abstraction, purification, mixing, filtration, putting and tight sealing in the container, sterilization, quality control, printing and packing 2. There are many ways to manufacturing herbal acupuncture, for example water-alcohol precipitation, alcohol-water precipitation, liquid-liquid abstract, acid-base abstract, metal base precipitation, distillation, molecular structure, polyamide absorption, dialysis, and ion exchange, etc. And popular method is water-alcohol precipitation. This is through alcohol precipitate extracting the principal ingredients from water abstraction. This is very simple and efficient way using melting characteristics of compounds in herb to water and ethanol. 3. Sterilization of herbal acupuncture is through heating-pressure, boiling, steam flowing, low temperature, filtering, radiation, cooling, and microwaves. Nowadays filtering is commonly used. And sterilization is estimated by an examination of asepsis . 4. Herbal acupuncture must be undergo study and experiment to clinical use. The problems of herbal acupuncture are turbidity, instability, causing hemolysis, pain, and fever. So many provisions (addition, sterilization, and filtration etc.) must be prepared. 5. The theory of manufacturing herbal acupuncture is from oriental medicine, not western. So it must be corresponded to oriental medical theory, for example Gimi(氣味), Guigyung(歸經), Ingyung(引經), Bosa(補瀉), and Match of Herb. It is recommended that further study of many other sided investigations in the future.

• Journal of the Korean Ceramic Society
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• v.43 no.5 s.288
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• pp.299-303
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• 2006

In this paper, anode supported SOFC with columnar structured YSZ electrolyte was fabricated via Electron Beam Physical Vapor Deposition (EBPVD) method. Liquid condensation process was employed for the preparation of NiO-YSZ substrate and the high power electron beam deposition method was used for the deposition of YSZ electrolyte film. Double layered cathode with LSM-YSZ and LSM was printed on electrolyte via screen-printing method and fired at $1150^{\circ}C$ in air atmosphere for 3 h. The electrochemical performance and the long-term stability of $5{\times}5cm^2$ single cell were investigated with DC current-voltage characteristics and AC-impedance spectroscopy. According to the investigation, $5{\times}5cm^2$ sized unit cell showed the maximum power density of around $0.76W/cm^2$ at $800^{\circ}C$ and maintained the stable performance over 400 h.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.87-94
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• 2008

Iris diagnosis is an alternative medicine technique whose proponents believe that patterns, colors, and other characteristics of the iris can be examined to determine information about a patient's systemic health. However, because most of previous studies only find a sign pattern in a gray iris image, they are not enough to be used for a iris diagnosis system. In this paper, we developed an iris diagnosis system based on a color image processing and iris medical information stored in database. The system includes four modules : input module with an iris camera, iris signs extraction module, medical database, output module with printing. Based on a color image processing approach, this paper presents the extraction algorithms of 7 major iris signs and correction manually for improving the accuracy of analysis. We can use the iridology and patient's health DB in the stage of signs analysis. Compared with the existing system, the developed system can be applied to an iris diagnosis system since it provides various additional functions.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.431-431
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• 2011

Graphene, two dimensional sheet of sp2-hybridized carbon, has attracted an enormous amount of interest due to excellent electrical, chemical and mechanical properties for the application of transparent conducting films, clean energy devices, field-effect transistors, optoelectronic devices and chemical sensors. Especially, graphene is promising candidate to detect the gas molecules and biomolecules due to the large specific surface area and signal-to-noise ratios. Despite of importance to the disease diagnosis, there are a few reports to demonstrate the graphene- and rGO-FET for biological sensors and the sensing mechanism are not fully understood. Here we describe scalable and facile fabrication of rGO-FET with the capability of label-free, ultrasensitive electrical detection of a cancer biomarker, prostate specific antigen/${\alpha}1$-antichymotrypsin (PSA-ACT) complex, in which the ultrathin rGO sensing channel was simply formed by a uniform self-assembly of two-dimensional rGO nanosheets on aminated pattern generated by inkjet printing. Sensing characteristics of rGO-FET immunosensor showed the highly precise, reliable, and linear shift in the Dirac point with the analyte concentration of PSA-ACT complex and extremely low detection limit as low as 1 fg/ml. We further analyzed the charge doping mechanism, which is the change in the charge carrier in the rGO channel varying by the concentration of biomolecules. Amenability of solution-based scalable fabrication and extremely high performance may enable rGO-FET device as a versatile multiplexed diagnostic biosensor for disease biomarkers.

• The Research Journal of the Costume Culture
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• v.13 no.2 s.55
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• pp.269-279
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• 2005

Okso, Keun Seob($1671\sim1759$) was descended from a noble family of Noreun(노론) and learned from his uncle, Keun Sang-ha who is a disciple of Song Si-Yeol, Kim Chang-hyeub and Kim Chang-heub. His $\lceil$Oksoko$\rfloor$ remains in the form of a transcription or a lithographic printing, and documents on 'Hakchangeui' are recorded in jabeui(잡의), Euijedogi(의제도기), which is a part of it. He left Seoul in 1714, settled in Chungpung, journeyed to many places, including the Hwang river area and Jecheon and led a literary and artistic life as Sadaebu(사대부), which was written in a collection of his works where the record about 'Hakchangeui', the most suitable clothes for the life of a retired scholar remains today to express one part of his life. This study introduces data about Hakchangeui written in $\lceil$Oksoko$\rfloor$, pursues the reason why Okso, Keun Seob told about it and intends to embody the figure of Hakchangeui based on the system, measure, material, and sewing method according to the records in a collection. Hakchaneui described in $\lceil$Oksoko$\rfloor$ reveals a structure that is different from old Hakchaneui, showing characteristics like the following. It is a Sadaebu's costume for field amusement in which the length of a former part is longer than that of a later part and the side seam of a garment rips. Black Yeon is attached to the white texture. Yeon widths of Git(collar), Sugu and Gil are varied, respectively. Yeon's figure attached to Gil and Somaejindong is a mountain. Git is Bangryeong and link parts between Git and Gil is connected with Sangchim. This Hakchangeui is considered to playas a gown because it has no string or support to adjust his dress. Especially we can identify that Hwayanggun(화양건) was used in this Hakchangeui.

• The Research Journal of the Costume Culture
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• v.25 no.6
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• pp.741-756
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• 2017

The natural resources of Jeju are recognized as the new regional image of that clean island. Reflecting these trends, this study is initiated to develop a textile design with the motive of persimmon, a natural resource of Jeju, and to apply it to infant's and children's clothes. Its purpose is to highlight the image of persimmon, a traditional dye, as a regional signature for Jeju. Product development procedure included, understanding the use of persimmon for fashion products, analyzing Infants' and Children's designer collections over the last three seasons (focused on 2014S/S, 2015S/S, and 2016S/S), and surveying the Children's Clothes market for persimmon dyeing in Jeju. The conclusion was that, the natural resources of Jeju are highly valuable, and should be applied to textile design and apparel products for children. Utilizing Jeju persimmon was actively studied, but, the market for the Jeju persimmon natural - dyeing products is extremely limited. Moreover, the apparel products for infants and children represent old-fashioned styles, despite their higher prices. Therefore, using the formative characteristics of persimmon for each theme was suggested for development of patterns for textile design. Pattern designs were expressed using textured textile screen-printing, embroidery and $appliqu{\acute{e}}$ for infants' and children's clothes. In this study, a total of 10 items were prepared as apparel products for infants and children. All items were designed considering mix-and-match, potential, with each other or with regular mass-market products. These results are expected to contribute to highlighting the unique image of Jeju and to help promote fashion culture products.

• Korean Journal of Materials Research
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• v.20 no.8
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• pp.408-411
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• 2010

Indium doped $SnO_2$ thick films for gas sensors were fabricated by a screen printing method on alumina substrates. The effects of indium concentration on the structural and morphological properties of the $SnO_2$ were investigated by X-ray diffraction and Scanning Electron Microscope. The structural properties of the $SnO_2$:In by X-ray diffraction showed a (110) dominant $SnO_2$ peak. The size of $SnO_2$ particles ranged from 0.05 to $0.1\;{\mu}m$, and $SnO_2$ particles were found to contain many pores, according to the SEM analysis. The thickness of the indium-doped $SnO_2$ thick films for gas sensors was about $20\;{\mu}m$, as confirmed by cross sectional SEM image. Sensitivity of the $SnO_2$:In gas sensor to 2000 ppm of $CO_2$ gas and 50 ppm of H2S gas was investigated for various indium concentrations. The highest sensitivity to $CO_2$ gas and H2S gas of the indium-doped $SnO_2$ thick films was observed at the 8 wt% and 4 wt% indium concentration, respectively. The good sensing performances of indium-doped $SnO_2$ gas sensors to $CO_2$ gas were attributed to the increase of oxygen vacancies and surface area in the $SnO_2$:In. The $SnO_2$:In gas sensors showed good selectivity to $CO_2$ gas.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.51-55
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• 2011

In this paper, the optimized doping condition of crystalline silicon solar cells with 156 ${\times}$ 156 mm2 area was studied. To optimize the drive-in condition in the doping process, the other conditions except drive-in temperature and time were fixed. After etching 7 ${\mu}m$ of the surface to form the pyramidal structure, the silicon nitride deposited by the PECVD had 75~80 nm thickness and 2 to 2.1 for a refractive index. The silver and aluminium electrodes for front and back sheet, respectively, were formed by screen-printing method, followed by firing in $400-425-450-550-850^{\circ}C$ five-zone temperature conditions to make the ohmic contact. Drive-in temperature was changed in range of $828^{\circ}C$ to $860^{\circ}C$ and time was from 3 min to 40 min. The sheet resistance of wafer was fixed to avoid its effect on solar cell. The solar cell fabricated with various conditions showed the similar conversion efficiency of 17.4%. This experimental result showed the drive-in temperatures and times little influence on solar cell characteristics.