• Journal of Environmental Science International
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• v.11 no.7
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• pp.757-763
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• 2002

The objective of this study is to delineate removal efficiency of the Linear alkylbenzene sulfonates(LAS) in solution by $TiO_2$ photocatalytic oxidation as a function of the following different experimental conditions : initial concentration of LAS, $TiO_2$ concentration, UV wavelength and pH of the solution. It was increased with decreasing initial concentration of LAS and with decreasing pH of the solution. Removal efficiency increased with increasing $TiO_2$ concentration but was almost the same at $TiO_2$ concentration of 2 g/L and 3 g/L, i.e., for initial LAS concentration of 50 mg/L. It was removal efficiency was 85% at 150 min in the case of $TiO_2$ concentration of 0.5 g/L but 100% after 150 min in the case of $TiO_2$ concentration of 1 g/L, 100% after 110 min in the case of $TiO_2$ concentration of 2 g/L and 3 g/L. UV wavelength affection on the removal efficiency of LAS decreased in the order of 254, 312 and 365 nm as increasing wavelength. But the removal efficiency of LAS was nearly the same at UV wavelength of 254 nm and 312 nm.

• Journal of Powder Materials
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• v.10 no.4
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• pp.262-269
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• 2003

Nano-sized Ni-ferrite powder was fabricated by spray pyrolysis process using the waste solution resulting from shadow mask processing. The average particle size of the powder was below 100 nm. The effects of the concentration of raw material solution, the nozzle tip size and air pressure on the properties of powder were studied. As the concentration increased, the average particle size of the powder gradually increased and its specific surface area decreased, but size distribution was much wider and the fraction of the Ni-ferrite phase greatly increased as the concentration increasing. As the nozzle tip size increased from 1 mm to 2 mm, the average particle size of the powder decreased. In case of 3 mm nozzle tip size, the average particle size of the powder increased slightly. On the other hand, in case of 5 mm nozzle tip size, average particle size of the powder decreased. Size distribution of the powder was unhomogeneous, and the fraction of the Ni-ferrite phase decreased as the nozzle tip size increasing. As air pressure increased up to 1 kg/$cm^2$, the average particle size of the powder decreased slightly, on the other hand, the fraction of the Ni-ferrite phase was almost constant. In case of 3kg/$cm^2$ air pressure, average particle size of the powder and the fraction of the Ni-ferrite phase remarkably decreased, but size distribution was narrow.

• Journal of KIBIM
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• v.13 no.2
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• pp.16-28
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• 2023

The concept of the Metaverse has been around not only for play but also for daily use. The interest in Metaverse is increasing, and various industries such as medicine, media, and financial started to use the new technology for diverse purposes. In addition, interest in the Metaverse is increasing in the architectural industry, but not much research has been done yet. Recently, some studies started to study focusing on the architectural design of Metaverse and the technological characteristics of Metaverse. However, there are limited studies about the utilization of the Metaverse in the architectural design process or construction process. From this perspective, the study aims to analyze the applicability of the Metaverse in the architectural design process through Metaverse case studies. In order to accomplish the research goal, the study classified user experience and technology of Metaverse in the literature review and Metaverse use in other industries such as commercial, medical, media entertainment, and construction industry. Then, this study analyzes six representative Metaverse platforms according to the application of Metaverse in the architectural design process. Finally, this study discussed the future direction and potential of Metaverse application in the Architectural design process.

• Research in Community and Public Health Nursing
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• v.13 no.3
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• pp.444-455
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• 2002

Purpose: This study was performed to develop the case management program that can provide the qualitative health care service to satisfy the increasing needs for health care elderly and prevent the increase in medical cost cased by prolonged and repetitive hospitalization. Method: The survey was completed as follows. First, 290 elderly patients who would be soon discharged in 4 hospitals are participated in the survey on needs of nursing care and case management programs. Second, 70 professionals working at 5 hospitals including doctors, nurses, social workers and so on are participated in the survey on the case management team operation. Result: Level of needs to Nursing care and case management programs showed so high. Professionals suggested on the case management team operation. Finally, based on the survey and literature review, the case management program was developed. Conclusion: In this study, the specific models for the five case management services were suggested. It is thought that the service provision by the case management team based on the multi-disciplinary case management program model suggested in this study would be suggested as a constituent of the effective health care delivery system for the hospitalized elderly patients.

• Journal of the Korean Data and Information Science Society
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• v.21 no.1
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• pp.173-177
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• 2010

It is well known that if the parent distribution has a nonnegative support and has increasing failure rate, then all the order statistics have increasing failure rate (IFR). The result is not necessarily true in the case of bivariate distributions with dependent structures. In this paper we consider a symmetric bivariate exponential distribution and show that, two marginal distributions are IFR and the distributions of the minimum and maximum are constant failure rate and IFR, respectively.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.11-12
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• 2008

Poly(ethylene oxide)(PEO) of molecular weight of 300,000 was crosslinked by UV irradiation in the presence of crosslinker. The photochemical crosslinking of PEO was enhanced by the addition of dimethacrylate crosslinkers in the film. Percent conversion of the polymer into gel as well as water absorbency were investigated gravimetrically. Gel fraction of PEO films increased with increasing crosslinker concentration. In the case of photocrosslinked PEO films with benzophenone, gel fraction reached about 95%. The thermal behavior of crosslinked PEO films was characterized by thermogravimetric analysis. The maximum decomposition temperature increased with increasing crosslinker concentration.

• Journal of the Korean institute of surface engineering
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• v.27 no.1
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• pp.19-28
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• 1994

A study on adhesion property of evaporated Al-Cr films was conducted on steel sheet by using two-source evaporator. Adhesion of Al-Cr coated steel was evaluated by tape test after $180^{\circ}$bending. Adhesion was decreased with increasing the Cr content in Al-Cr films. It was thought that the decrease in adhesion with increasing Cr content be related to insufficient wetting and diffusion of Cr atoms in the film. Best adhesion was achieved in the case of pure aluminum film..

• Fire Science and Engineering
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• v.19 no.2 s.58
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• pp.37-44
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• 2005

We have conducted a numerical simulation under three-dimensional unsteady conditions in order to analyze the characteristics of flow and the distribution of $CO_2$ agent concentration according to the number of $CO_2$ agent nozzle. The engine room of a ship was selected as a protection space, and flow fields and $CO_2$ concentration fields were measured. In case of increasing the number of $CO_2$ nozzle from 2 nozzles to 4 nozzles, the distribution of CO2 concentration showed low, and in case of increasing the number of $CO_2$ nozzle to above 6 nozzles, the recirculating flow affected to all region was generated. In case of increasing the number of $CO_2$ agent nozzle to above 4 nozzles, the iso-concentration line below 0.36 expanded or contracted slightly. Therefor, the proper number and the arrangement of $CO_2$ agent nozzle are considered when $CO_2$ fire fighting system is designed.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.2
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• pp.58-66
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• 1991

This paper measured the characteristic of the thermal expansion, dielectric and conductivity to use $Sb_2O_3$ Filler in epoxy resin.The results are summarized as follow : 1 ) In the [$155^{\circ}C$] 1, The coefficient of thermal expansion increasing temperature obtained 8.19 in the case of pure epoxy resin and $4.5{\times}10^{-5}$ in the case of the mixing 7[%].2) The peak point of $\varepsilon\iota, \varepsilon\rho$ increasing $Sb_2O_3$ mixing ratio moved on the part of the high temperature. 3) The conductivity value increasing temperature shows the corner on the part of the Tg and it's Value became low the sample material with mixing I[%] than in case of pure epoxy resin.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2325-2332
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• 2017

Consulting projects such as diagnosis of vulnerabilities of major information and telecommunication infrastructure are increasing, mandatory public information infrastructure assessment (PIA) for public institutions and ISMS (Information Security Management System) The demand for information protection consulting is continuously increasing as the field obeys the law, but the lack of information security consultant is not improving. One reason is that information security consultants are not being developed to meet the increasing demand for information protection consulting. In this paper, we present the case of information protection consulting as a scenario for studying and educating the duty of information security consultant by studying overseas case and domestic case based on standardization and standardization. We propose a problem-based learning (PBL) training method. In addition, we analyze the effectiveness of the PBL - based learning method.