• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.11
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• pp.730-734
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• 1999

In this study, it is the purpose to develope a cheap and compact repetitively pulsed $CO_2$ laser with pulse repetition rate range of 180 Hz. We used a SCR switched power supply as a high voltage pulsed supply, which is cheap and simple comparing to others. PIC one-chip microprocessor was used for precise control of a laser power supply on the control part. And the laser cavity was fabricated as an axial and water cooled type. The laser performance characteristics as various parameters, such as pulse repetition rate and gas pressure have been investigated. The experiment was done under the condition of total pressure of $CO_2, N_2$ and He from 4 Torr to 16 Torr and pulse repetition rate from 4 Hz to 180 Hz. As a result, the maximum average output was about 19.6W at the total pressure of 12 Torr and the pulse repetition rate of 180Hz.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1698-1700
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• 2003

The electrostatic precipitator(ESP) is a device for removing particulate pollutants in the form of either a solid (dust or fumes) or a liquid (mist) from a gas using an electrostatic force, Electrostatic precipitation has been widely used for cleaning gas from almost all industrial processes with a medium to large gas volume(>2,000 $m^3/min$), including utility boilers, blast furnaces, and cement kilns. ESP is also in wide use for air cleaning in living environments (home, offices, hospitals, etc.) ESP has large advantages over other particulate control device : a low operating cost, a high collection performance, and ease of maintenance. The purpose of this study is to investigate the characteristics of the smoke removal of an air cleaner by adjusting variable frequency and monitoring of turbidity three results of this research are as follows ;the first is the best efficient switching frequency which is 60Hz, the second is the smoke removal time which is obtained to 9 seconds, third is that the best efficient firing angle is $90^{\circ}$ As a result, the switching trigger frequency and SCR gate firing angle is very important factor to predict the best collection efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4250-4256
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• 2011

Mn catalyst promoted with Cu were prepared and tested for selective catalytic reduction of $NO_x$ with $NH_3$. Performance of each catalyst was investigated for $NO_x$ activity while changing temperature, space velocity, water content and $O_2$ concentration. Hydrogen conversion efficiency of catalyst was also measured in the $H_2$-TPR system. The inhibition effect of water on catalyst was investigated with the on-off control of water supply. High activity of Mn-Cu catalyst was observed for $160{\sim}260^{\circ}C$. It is found that increase of oxygen concentration acts as a promotor to the increase of catalyst activity but water content acts as a inhibitor.

• Korean Journal of Clinical Pharmacy
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• v.9 no.1
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• pp.35-43
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• 1999

Over the last 50 years, a number of antibiotic agents have been developed and clinically used in the area of infectious diseases. Due to antimicrobial resistance problems and increasing health care costs, the rational use of antibiotics has been required. As a drug of choice to treat infections caused by MRSA, vancomycin has been extensively prescribed since the late 1970's. Recently, reports of vancomycin-resistant organisms such as VRE and VRSA have been increased to draw medical concerns. The objectives of this study were to evaluate the rational use of vancomycin and the appropriateness of the Restrictional Program of Antibiotic Utilization (RPAU) which has been operated at Samsung Medical Center. A retrospective chart review was performed in 132 hospitalized patients treated with vancomycin in the surgery departments from. January to June 1998. The guidelines of ASHP and HICPAC for vancomycin were modified and used as our criteria to determine the vancomycin DUE. In one hundred out of the patients, uses of vancomycin were approved by the Department of Infectious Diseases (DID) based on the RPAU. Vancomycin was appropriately used in $62.5\%$ of the 100 patients according to the criteria of justification of use, while $60.0\%,\;60.0\%,\;79.0\%,\;and\;51.0\%$ of the patients showed appropriate according to those of lab reports such as applicable culture obtained, pretreatment SCr, WBC and serum drug concentration monitoring, respectively. Although the rest 32 patients were not approved to receive vancomycin by the DID, twenty two percent continued receiving vancomycin treatment. This might result from the fact that the RPAU was started not before the use of antibiotics but in the middle of antimicrobial therapy. Continual education should be provide to the related health professionals and the RPAU should be simultaneously modified in order to increase the rate of appropriate uses of antibiotics.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.1
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• pp.17-22
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• 2011

As the quality of a weld joint is strongly influenced by process parameters the welding process, an intelligent algorithms that can predict the bead geometry and shape to accomplish the desired mechanical properties of the weldment should be developed. In this study, prepared by ${\Phi}1.6mm$ GMA welding of metal wire nose Advice jowelui 350A 600A grade level inverter welder and DAIHEN SCR's were carried out using welding. Welding conditions were 5.5m/min wire feed rate the welding current is rapidly transmit approximately 260A, welding voltage was about 30V. CTWD a 22mm, shielding gas was Ar 20L/min and the welding speed was a 240mm/min. Using data collected during welding equipment welding current and welding voltage waveform was analyzed by measuring the volume of the transition mode. Addition of $CaCO_3$ as a loss of the spread of the weld bead dilution rate decreased, suggesting that, GMA in the overlay welding bead shape control, dilution control and may be used as a welding flux is considered. Stabilizing effect of the arc by the Ca-containing $CaF_2$, $CaCO_3$, $CaMg(CO_3)_2$, respectively, welding flux 0.1wt.% added GMA welding and weld overlay were evaluated with dilution, $CaF_2$, and $CaMg(CO_3)_2$ added to the dilution of Seemed to increase.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.397-402
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• 2009

Self-incompatibility (SI) prevents self-fertilization by inhibiting the pollen tube growth of self-pollen. Molecular analysis has revealed that the S locus comprises a number of genes, such as the S-locus glycoprotein (SLG), the S-locus receptor kinase (SRK), and SP11 (SCR). Although molecular markers related to those genes have been developed, a simple S-haplotype detecting method has not been reported due to the highly polymorphic and relatively small coding regions. In this study, the sequence characterized amplified region (SCAR) markers were used to establish an efficient radish genotyping method. We identified the S-haplotypes of 192 radish accessions using 19 different markers, which proved to be highly reliable. The accessions were assigned to 17 types of S-haplotypes, including 8 types of SRKs and 9 types of SLGs. Since the developed SCAR markers are based on their gene sequences, we could easily identify the S-haplotypes by a single specific band, with the highest frequencies detected for SLG 5, SRK 1, and SLG 1, in order. Among the tested markers, the SLG 1, SRK 1, and SRK 5 markers exhibited high reliability, compared to phenotypic results. Furthermore, we identified the seven types of unreported SLGs using SLG Class -I and -II specific markers. Although the developed SCAR markers still need to be improved for the genotyping of all S-haplotypes, these markers could be helpful for monitoring inbred lines, and for developing the MAS in radish breeding programs.

• Particle and aerosol research
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• v.15 no.1
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• pp.1-13
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• 2019

Current desulfurization and denitrification technologies have reached a considerable level in terms of reduction efficiency. However, when compared with the simultaneous reduction technology, the individual reduction technologies have issues such as economic disadvantages due to the difficulty to scale-up apparatus, secondary pollution from wastewater/waste during the treatment process, requirement of large facilities for post-treatment, and increased installation costs. Therefore, it is necessary to enable practical application of simultaneous SOx and NOx treatment technologies to remove two or more contaminants in one process. The present study analyzes a technology capable of maintaining simultaneous treatment of SOx and NOx even at low temperatures due to the electrochemically generated strong oxidation of the wet-pulse complex system. This system also reduces unreacted residual gas and secondary products through the wet scrubbing process. It addresses common problems of the existing fuel gas treatment methods such as SDR, SCR, and activated carbon adsorption (i.e., low treatment efficiency, expensive maintenance cost, large installation area, and energy loss). Experiments were performed with varying variables such as pulse voltage, reaction temperature, chemicals and additives ratios, liquid/gas ratio, structure of the aeration cleaning nozzle, and gas inlet concentration. The performance of individual and complex processes using the wet-pulse discharge reaction were analyzed and compared.

• International Area Studies Review
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• v.13 no.2
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• pp.550-572
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• 2009

This paper investigates the textile negotiations between Korea and the U.S. which Korea, as a weaker party in the bilateral trade negotiation, was recognized as making a good performance by Odell(1985). Using the documents of Korean governments at the time - Ministry of Foreign Affairs and the Ministry of Commerce and Industry - telegrams and reports from various sources the paper picks a leveling factor during the negotiations. In the paper, we used a dynamic concept of power for describing the negotiating power, and showed Korea succeeded in making the negotiation symmetric using the Special Cooperative Relationship(SCR) as one of the most conspicuous leveling factors during the textile negotiations with the U.S. The paper contributes to finding the factors that can be used in the negotiations with power asymmetry as a leveling factor for weaker country. Also, based on the findings from the paper, future negotiators can get insights on which factors be used, and how to use those factors for leveling the negotiations with a stronger counterpart.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.237-242
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• 2021

Simultaneous removal technologies of multi-pollutants such as particulate matters (PMs), NOx, SOx, VOCs and ammonia have received consistent attention due to the enhancement of pollutant abatement efficiency in addition to the stringent environmental regulation and emission standard. Pretreatment of insoluble NO by an ozone oxidation can be considered to be more effective route for saving space occupation as well as operation cost in comparison with that of traditional selective catalytic reduction (SCR) process. Moreover the primary advantage of ozone oxidation process is that the simultaneous removal with acidic gas including SOx is also available. Herein, we highlight recent studies of multi-pollutant abatement via ozone oxidation process and the promising research topics for better application in industrial sectors.

• Corrosion Science and Technology
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• v.22 no.3
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• pp.187-192
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• 2023

The use of biomass is increasing as a response to the convention on climate change. In Korea, a method applied to replace fossil fuels is using wood chips in a cogeneration plant. To remove air pollutants generated by burning wood chips, a selective denitrification facility (Selective catalytic reduction, SCR) is installed downstream. However, problems such as ash deposition and descaling of the equipment surface have been reported. The cause is thought to be unreacted ammonia slip caused by ammonia ions injected into the reducing agent and metal corrosion caused by an acidic environment. Element analysis confirmed that ash contained alkali metals and sulfur that could cause catalyst poisoning, leading to an increase in the size of ash particle and deposition. Measurement of the size of ash deposited inside the facility confirmed that the size of ash deposited on the catalyst was approximately three times larger than the size of generally formed ash. Therefore, it was concluded that a reduction in pore area of the catalyst by ash deposition on the surface of the catalyst could lead to a problem of increasing differential pressure in a denitrification facility.