• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• Journal of Life Science
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• v.12 no.6
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• pp.721-730
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• 2002

This study was carried out to select new pelleting binder and material for Welsh onion seeds. The optimum treatments of the various plant growth regulators to improve seed germination of the Welsh onion was also estimated. There were no significant effects of growth regulators on the germination percentage, but germination was faster according to the number of days to 50% of the final germination ($T_{50}$) and the mean number of days to germination (MDG) than those of the control. Germinability was increased when the seeds were soaked in gibberellic acid ($GA_3$) solution for 24hrs, even though there was no synergy effect on the germinability when $GA_3$ was mixed with 6-benzylaminopurine (BAP). The optimum treatment for improving germination of Welsh onion was observed when the tested seeds was soaked in 500 $\mu$M of $GA_3$ at $20^{\circ}C$ for 24hrs. Also, when the seeds soaked in the aforementioned treatment, the rate of germination was increased at lower temperature than at $20^{\circ}C$, the optimal temperature. The percentage and the speed of seed germination depended on the kinds of pelleting binder and their concentration. It showed that the higher the concentration of the binder for seeds pelleting, the lower the percentage of seed germination. Among the pelleting binder, polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) were the best binders for seed pelleting, because seed germination using those binder did not affect on the concentration of binder. On the other hand, Carboxymethy cellulose (CMC) and methyl cellulose (MC) severely inhibited the seed germination The germinability was also different arcording to the pelleting materials. Among the different 58 pelleting materials, kaoline alone, the mixture of bentonite and kaoline, the mixture of bentonite, calcium carbonate and diatomaceous earth #300 were found as the best pelleting materials for welsh onion seeds.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4678-4702
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• 2018

Traffic Matrix estimation has always caught attention from researchers for better network management and future planning. With the advent of high traffic loads due to Cloud Computing platforms and Software Defined Networking based tunable routing and traffic management algorithms on the Internet, it is more necessary as ever to be able to predict current and future traffic volumes on the network. For large networks such origin-destination traffic prediction problem takes the form of a large under- constrained and under-determined system of equations with a dynamic measurement matrix. Previously, the researchers had relied on the assumption that the measurement (routing) matrix is stationary due to which the schemes are not suitable for modern software defined networks. In this work, we present our Compressed Sensing with Dynamic Model Estimation (CS-DME) architecture suitable for modern software defined networks. Our main contributions are: (1) we formulate an approach in which measurement matrix in the compressed sensing scheme can be accurately and dynamically estimated through a reformulation of the problem based on traffic demands. (2) We show that the problem formulation using a dynamic measurement matrix based on instantaneous traffic demands may be used instead of a stationary binary routing matrix which is more suitable to modern Software Defined Networks that are constantly evolving in terms of routing by inspection of its Eigen Spectrum using two real world datasets. (3) We also show that linking this compressed measurement matrix dynamically with the measured parameters can lead to acceptable estimation of Origin Destination (OD) Traffic flows with marginally poor results with other state-of-art schemes relying on fixed measurement matrices. (4) Furthermore, using this compressed reformulated problem, a new strategy for selection of vantage points for most efficient traffic matrix estimation is also presented through a secondary compression technique based on subset of link measurements. Experimental evaluation of proposed technique using real world datasets Abilene and GEANT shows that the technique is practical to be used in modern software defined networks. Further, the performance of the scheme is compared with recent state of the art techniques proposed in research literature.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.89-89
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• 1995

Surface epithelial cells isolated from hamster tracheas and grown on a thick collagen gel become a highly enriched population of mucus-secreting cells. Epithelial cells from tracheas of hamsters were collected using enzymatic procedures and cultured under various conditions. The medium used consisted of a 1:1 mixture of medium 199 and Dulbecco's modified Eagle's (DME) medium which was conditioned before use. Insulin, transferrin, hydrocortisone, epidermal growth factor, and extract from bovine hypothalamus were used as supplement. Due to relatively low basal rates of min secretion from in vitro cultures, cultures are generally radiolabeled using $^3$H-glucosamine as a metabolic precursor. The radiolabeled mucinsreleased are quantitated by precipitation with TCA/PTA. Using this cell culture system, we investigated mucin release of goblet cells by altering the media bathing the apical surface of hamster tracheal surface epithelial(HTSE) cells. Acidic media added sulfuric acid caused sigcificant increases in mucin relesse (155${\pm}$20% at pH 4 and 146${\pm}$16% at, pH 5). Ammonium hydroxide also increased mucin release at pH 9.0(156${\pm}$17%) and pH 10(295${\pm}$9%) respectively. This additional mucin release seems to be associated with cell membrane damage as indicated by release of cellular LDH. SP stimulates secretion of mucin in cultured HTSE cells(154${\pm}$16% at 1${\times}$10$\^$-6/M and 165${\pm}$25% at 1${\times}$10$\^$-5/M. PAF at 5${\times}$10$\^$-6/M and 5${\times}$10$\^$-5/M enhanced by HTSE cells in vitro 168${\pm}$34% and 259${\pm}$30% of mucin secretion, respectively. The increase in mucin release by PAF and SP was not secondary to cell damage or necrosis. SP and PAF may be in mediating mucous secretion induced by inflammation irritantion and infection.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.135-142
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• 1989

Methyl tert-butyl ether(MTBE) was synthesized from vapor phase reaction of methanol with iso-butylene over HZSM-5 catalysts, and effects of SiO$_2/Al_2O_3$ ratio in the HZSM-5 catalysts and reaction conditions on products distribution have been examined. Acid strength and acid type of each catalyst with different SiO$_2/Al_2O_3$ ratio were measured using pyridine adsorption followed by temperature programmed desorption(TPD) and IR analysis. Reactants and products adsorption characteristics on different acid sites have also been examined. As the SiO$_2/Al_2O_3$ ratio of HZSM-5 catalyst was increased, selectivity to MTBE was improved as a result of decrease in dimethylether(DME) formation at the strong acid sites. Conversion and selectivity to MTBE were also greatly enhanced as $i-C_4H_8/CH_3OH$ reactant ratio was increased, and overall about 80$^{\circ}$C was adequate for the MTBE synthesis. The properties of deposited coke on spent catalysts were examined by TG, DTA and IR spectrum analysis, indicating the amount of the coke deposit in the order of HY > H-Mordenite > HZSM-5. Even if the coke deposited on H-Mordenite was little more in amount than to that on HZSM-5, the former deactivated quickly due to its non-interconnected channel structure. For HY, owing to its lange pore size, significant $i-C_4H_8$ polymerization was occured, and rapid deactivation and severe coke formation has resulted within few hours.

• Korean Journal of Heritage: History & Science
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• v.50 no.2
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• pp.4-25
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• 2017

The Hoeamsa Temple of Yangju City was established at least during the late Korea Dynasty. This temple was rebuilt several times with the support of the royal family from the late Korea Dynasty to the early Joseon Dynasty. It was continually rebuilt in association with JiGong monk, HyeKeun monk, and MuHak monk. Hoeamsa temple was leading the Buddhist culture as a Buddhist center of the Joseon Dynasty . It was destroyed in the late Joseon Period. This site has been excavated several times since 1997. Various roofing tiles were unearthed. Of these tiles the edge of eaves are the artifacts showing the best features of this era. In this temple site has been excavated a variety of Sanskrit roof tiles. These tiles were made using superior technique. On the roof tiles are engraved Sanskrit mantras with a variety of 1 to 9 words. The jeongbeopkkye mantra(oṃ raṃ) and six-word mantra(oṃ ma ṇi pa dme hūṃ) were discovered the most. These mantras were believe to expel several evils from the Buddhist temple. It must have been that the six-word mantra culture became prevalent and provided a turning point in the history of Korean Buddhism. We can clearly know when some of the Sanskrit roof tiles were first manufactured. These roof tiles are the absolute standard of the other Sanskrit roof tiles excavated from different Buddhist temples. The master craftsmen must have been very skilled, understood the mantra very well, and had deep faith in the Sanskrit mantra. Hoeamsa Temple is a milestone in studying the Sanskrit roof tiles. More studies on various aspects are expected to be followed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.844-861
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• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.