• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.56.3-57
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• 2015

As of early 2015, more than 12,000 Near-Earth Objects (NEOs) have been catalogued by the Minor Planet Center, however their observational properties such as broadband colors and rotational periods are known only for a small fraction of the population. Thanks to time series observations with the KMTNet, orbits, optical sizes (and albedo), spin states and three dimensional shapes of asteroids and comets including NEOs will be systematically investigated and archived for the first time. Based on SDSS and BVRI colors, their approximate surface mineralogy will also be characterized. This so-called DEEP-South (Deep Ecliptic Patrol of the Southern Sky) project will provide a prompt solution to the demand from the scientific community to bridge the gaps in global sky coverage with a coordinated use of the network of ground-based telescopes in the southern hemisphere. We will soon finish implementing dedicated software subsystem consisted of automated observation scheduler and data pipeline for the sake of increased discovery rate, rapid follow-up, timely phase coverage, and efficient data analysis. We will give a brief introduction to test runs conducted at CTIO with the first KMTNet telescope in February and March 2015 and experimental data processing. Preliminary scientific results will also be presented.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.86-86
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• 2012

The new approaches for silicon solar cell of new concept have been actively conducted. Especially, solar cells with wire array structured radial p-n junctions has attracted considerable attention due to the unique advantages of orthogonalizing the direction of light absorption and charge separation while allowing for improved light scattering and trapping. One-dimenstional semiconductor nano/micro structures should be fabricated for radial p-n junction solar cell. Most of silicon wire and/or pillar arrays have been fabricated by vapour-liquid-solid (VLS) growth because of its simple and cheap process. In the case of the VLS method has some weak points, that is, the incorporation of heavy metal catalysts into the growing silicon wire, the high temperature procedure. We have tried new approaches; one is electrochemical etching, the other is noble metal catalytic etching method to overcome those problems. In this talk, the silicon pillar formation will be characterized by investigating the parameters of the electrochemical etching process such as HF concentration ratio of electrolyte, current density, back contact material, temperature of the solution, and large pre-pattern size and pitch. In the noble metal catalytic etching processes, the effect of solution composition and thickness of metal catalyst on the etching rate and morphologies of silicon was investigated. Finally, radial p-n junction wire arrays were fabricated by spin on doping (phosphor), starting from chemical etched p-Si wire arrays. In/Ga eutectic metal was used for contact metal. The energy conversion efficiency of radial p-n junction solar cell is discussed.

• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.149-155
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• 2015

Purpose : Recently, many researchers and golf coachers demonstrated that X-factor and X-factor stretch had a co-relationship with driving distance. However, its relationship is still controversial and ambiguous. Thus, the aim of this study was to examine the relationship among X-factor, X-factor stretch and swing-related factors, including driving distance in elite golfers. Method : Seventeen male elite golfers (handicap: ${\leq}4$) with no history of musculo-skeletal injuries participated in the study. Thirty spherical retro-reflective markers were placed on including the middle point of PSIS, the right/left ASIS, the right/left lateral acromion of the scapula, driver head and shaft grip. All motion capture data was collected at 100Hz using 6 infrared cameras. Carry distance, club speed, ball speed, smash factor, launch angle, and spin rate were collected from radar-based device, TrackMan. Results : Pearson's correlation coefficient method was used to find the correlations among X-factor, X-factor stretch and swing-related factors. Positive correlations between driving distance and other swing-related factors which include club speed(r=.798, p<.001), and ball speed(r=.948, p<.001) were observed. In contrast to the swing-related factors, X-factor and X-factor stretch had no relationship to driving distance. Conclusion : These results indicate that X-factor and X-factor stretch are not key regulators in driving distance.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.15-18
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• 2000

Transparent conducting tin (IV) oxide thin films have been studied and developed for the electrode materials of solar cell substrate. Fabrication of tin oxide thin films by sol-gel method is process development of lower cost photovoltaic solar cell system. The research is focused on the establishment of process conditions and development of precursor. The precursor solution was made of tin isopropoxide dissolved in isopropyl alcohol. The hydrolysis rate was controlled by addition of triethanolamine. Dip and spin coating technique were applied to coat tin oxide on borosilicate glass. The resistivity of the thin film was lower than 0.01-cm and the transmittance is higher than $90\%$ in a visible range.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.1
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• pp.62-68
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• 2006

High temperature electrolysis is a promising technology to produce massively hydrogen using renewable and nuclear energy. Solid oxide fuel cell materials are candidates as the components of steam electrolysers. However, the polarization characteristics of the typical electrode materials during the electrolysis have not been intensively investigated. In this study, NiO electrode was deposited on YSZ electrolyte by spin coat process and firing at $1300^{\circ}C$. Pt electrode was applied on the other side of the electrolyte to compare the polarization characteristics with those by NiO during electrolysis. The $H_2$ evolution rate was also monitored by measuring the electromotive force of Lambda probe and calculated by thermodynamic consideration. At low current density, Pt showed lower cathodic polarization and thus higher current efficiency than Ni, but the oxidation of Ni into NiO caused the increase of anodic resistance with increasing current density. High overpotential induced high power consumption to produce hydrogen by electrolysis.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.60-65
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• 1999

Purpose : The purpose of this study was to evaluate the image quality, contrast characteristics, and possible clinical utility of Medium Tau Inversion Recovery(MTIR) sequence with white matter suppression in patients with brain cortical lesion. Materials and methods : Two normal volunteers and twenty-one patients with cortical lesion were scanned with MTIR as well as other MR imaging sequences. Gray-white matter contrast was evaluated objectively using region-of-interest calculations, including percent contrast and contrast-to-noise ratio(CNR). MTIR sequence was visually compared with other sequences in 21 patients with cortical lesion including conspicuity and detection rate. Results : MTIR sequence had the highest present contrast and CNR between the gray matter and white matter. In twenty-one cases of cortical lesion including cortical dysplasia, MTIR sequence improved delineation and conspicuity of lesion, but MTIR sequence could not detect new lesions. Conclusion : The MTIR sequence well delineated the cortical lesions, particularly in including cortical dysplasia. It may be used as an adjunctive imaging sequence in case of poor gray and white matter differentiation with conventional T1-weighted sequences.

• Journal of Acupuncture Research
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• v.19 no.6
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• pp.1-11
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• 2002

Objective : Korean medicine treatment method is noted as alternative in treating traffic accidents(TA) victims recently. The main purpose of this research is to make a survey of the effective way of the Korean medicine treatment about TA victims. Methods : In following research, 389 cases of traffic victims who hospitalized in the Youngsaeng Korean Medicine Hospital & Youngsaeng Clinic from March 1, 2001 to November 30, 2001 were surveyed. The research is focused on finding out the distribution, such as sex and age, damaged part of the body of 389 TA victims, nature of damage of 389 TA victims, chief complaint of 389 TA victims, nature of damage by Korean medicine code classification, treatment given to 389 TA victims, Extract(Ex) medicine given to 389 TA victims, days in hospital of 389 TA victims. Results : The patients reached korean medicine hospital in fewer numbers from most of TA victims. As neck pain and L-spin sprain, most of symptoms was light and the treatment of medicine as well was limited for TA. The treatment method which was used for treating TA was acupuncture, cupping therapy, physical therapy, Ex medicine. Few ways could use the Ex medicine as well. Conclusions : The achieving rate of treatment was marked highly by using Haenggi(行氣) Hwalhyeol(活血) Guyea(祛瘀) and we confirmed a possibility for the treatment of TA in korean medicine treatment method. It needs to increase all kinds of treatment-ways which can treat successfully and needs to come into application of insurance. Korean medicine method will have possibility to take part in TA injury admission, by presenting basis to prove effectiveness of treatment-ways.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.266-272
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• 2002

The stochiometric mixture of evaporating materials for the ZnIn$_2$S$_4$ single crystal thin film was prepared from horizontal furnace. To obtain the ZnIn$_2$S$_4$ single crystal thin film, ZnIn$_2$S$_4$ mixed crystal was deposited on throughly etched semi-insulating GaAs(100) in the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were 610 $^{\circ}C$ and 450 $^{\circ}C$, respectively and the growth rate of the ZnIn$_2$S$_4$ single crystal thin film was about 0.5 $\mu\textrm{m}$/hr. The crystalline structure of ZnIn$_2$S$_4$ single crystal thin film was investigated by photo1uminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of ZnIn$_2$S$_4$ single crystal thin film measured from Hall effect by van der Pauw method are 8.51${\times}$10$\^$17/ cm$\^$-3/, 291 $\textrm{cm}^2$/V$.$s at 293 $^{\circ}$K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the ZnIn$_2$S$_4$ single crystal thin film, we have found that the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 0.0148 eV and 0.1678 eV at 10 $^{\circ}$K, respectively. From the photoluminescence measurement of ZnIn$_2$S$_4$ single crystal thin film, we observed free excition (E$\_$X/) typically observed only in high quality crystal and neutral donor bound exciton (D$^{\circ}$,X) having very strong peak intensity. The full width at half maximum and binding energy of neutral donor bound excition were 9 meV and 26 meV, respectively. The activation energy of impurity measured by Haynes rule was 130 meV.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.5
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• pp.617-627
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• 2006

Statement of problem: HA has been used as a coating material on Ti implants to improve osteoconductivity. However. it is difficult to form uniform HA coatings on implants with complex surface geometries using a plasma spraying technique. Purpose : To determine if Ti6Al4V sintered porous-surfaced implants coated with HA sol-gel coated and hydrothermal treated would accelerate osseointegration. Materials and Methods : Porous implants which were made by electric discharge were used in this study. Implants were anodized and hydrothermal treatment or HA sol-gel coating was performed. Hydrothermal treatment was conducted by high pressure steam at $300^{\circ}C$ for 2 hours using a autoclave. To make a HA sol, triethyl phosphite and calcium nitrate were diluted and dissolved in anhydrous ethanol and mixed. Then anodized implant were spin-coated with the prepared HA sols and heat treated. Samples were soaked in the Hanks solution with pH 7.4 at $37^{\circ}C$ for 6 weeks. The microstructure of the specimens was observed with a scanning electron microscope (SEM), and the composition of the surface layer was analyzed with an energy dispersive spectroscope (EDS). Results : The scanning electron micrographs of HA sol-gel coated and hydrothermal treated surface did not show any significant change in the size or shape of the pores. After immersion in Hanks' solution the precipitated HA crystals covered macro- and micro-pores The precipitated Ca and P increased in Hanks' solution that surface treatment caused increased activity. Conclusion : This study shows that sol-gel coated HA and hydrothermal treatment significantly enhance the rate of HA formation due to the altered surface chemistry.

• Textile Coloration and Finishing
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• v.30 no.3
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• pp.199-207
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• 2018

In this study, the properties of polypropylene(PP) non-woven fabric spun under various conditions by the Melt-blown method were verified, and the deodorant content and deodorization of PP non-woven fabric after deodorant-treatment were investigated. PP non-woven fabrics are manufactured by varying the temperature of spin beam, hot air temperature and amount, the RPM of collector R/O and the distance between collector and spinneret, which affects the structure of the non-woven fabric. After that, the structural characteristics and air permeability of the non-woven fabric were measured. The experimental results show that the amount of air, the distance between the collector and the spinneret significantly affect the structural characteristics and air permeability of the PP non-woven fabric. And, regardless of the weight of the PP non-woven fabric, the deodorizing effect of UiO-66 MOF deodorant add-on ratio and content was higher.