• Membrane Journal
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• v.3 no.1
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• pp.29-34
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• 1993

Reverse osmosis(RO) and pervaporation(PV) membrane processes were compared with each other theoretically by using Paul and Ebra-Lima model. From this model the concentrations of liquid within the membrane when pressure was applied to the upper compartment(for PV case, the applied pressure is infinite) were calculated for rubber membrane-n-hexane and rubber membrane-benzene systems. The permeabilities of RO and PV were also calculated and compared for polyethylene film-n- hexane and polyethylene film- benzene systems Theoretically, the permeabilities of PV membrane were greater than those of RO membrane.

• Journal of Ginseng Research
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• v.9 no.2
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• pp.204-212
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• 1985

Lipid and fatty acid compositions of the bound lipids in Panax quinquefolium (Korea, Japan and China), Panax quinquefolium (America, Canada) and Panax notoginseng (China) were studied by means of silicic acid column chromatography, thin-layer chromatography and gas-liquid chromatography. The could lipid contents in various ginsengs were 0.29 to 0.48%, in which neutral lipid fractions were 63.6 to 67.3%, glycolipid fractions 21.9 to 25.7% and phospholipid fractions 7.7 to 12.4%. The content compositions of neutral lipid fractions were lower and those of glycolipid and phospholipid fractions were higher in the bound lipids than in the free lipids from the various ginseng. The major components were fatty acids, diglycerides and free sterols in neutral lipid fractions, monogalactosyl diglyceride, sterol glucoside and esterified steryl g1ycoside in glycolipid fractions and phosphatidyl glycerol, phosphatidyl ethanolamine and phosphatidic acid in phosphoipid fractions. Seventeen fatty acids were analyzed in the four bound lipid fractions from the various ginsengs and main fatty acids were linoleic acid, palmitic acid and oleic acid. Total saturated fatty acid and palmitic acid contents were higher and total unsaturated fatty acid and linoleic acid contents lower in the total bound lipids than in the total free lipids from the various ginsengs.

• Journal of Ginseng Research
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• v.9 no.2
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• pp.193-203
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• 1985

Lipid and fatty acid compositions of the free lipids in Panax ginseng (Korea, Japan and China), Panax quinquefolium (America, Canada) and Panax notoginseng (China) were studied by means of silicic acid column chromatography, thin-layer chromatography and gas-liquid chromatography. Free lipid contents were 1.13 to 1.24% in panax ginseng and 0.87 to 1.18% in Panax quinquefolium and 0.39% in panax notoginseng. Neutral lipid fractions were 81.2 to 84.4%, while glycolipid fractions 8.01% to 14.47% and phospholipid fractions 3.49 to 5.74% in free lipid contents. The major components were triglycerides, free sterols, diglyceride, free fatty acids and sterol esters in neutral lipid fractions, sterol glucoside, monogalactosyl diglyceride, digalactosyl diglyceride, esterified steryl glucoside in glycolipid fractions and phosphatidyl glycerol, phosphatide, ethanolamine, phosphatidyl choline in phospholipid fractions. The contents and compositions of neutral lipids and glyclipids were some different among various ginsengs, whereas phospholipids showed relatively similar compositions in the contents. Seventeen fatty acids were analyzed in the four free lipid fractions from the various ginsengs and the main fatty acids were linoleic acid, palmitic acid, oleic acid and linolenic acid. It was found that the amounts of some fatty acids were different among the various ginsengs, but the fatty acid patterns of these ginsengs were on the whole similar.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.153-158
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• 2019

It is estimated that about 2,515 persons have been injured by conveyor for the past five years(2013 ~ 2017). Conveyors used in various industrial sites for transporting iron ore, coal, courier goods, etc., have various incidents such as a worker putting on or pulling a part of the body or work clothes on the driving part during maintenance. It is necessary for preventing similar accidents to conduct various researches. In order to propose the basis for revising laws and standards for the safety standards of the full cord switch to prevent conveyor accidents, this study compares Korea's Industrial Safety and Health Law (KISHL) with those of IEC, EN, Canada, and Australia. In addition, surveys of conveyor use plant and full cord switch domestic and foreign manufacturers was conducted. In this study, domestic and overseas related laws and technical standards compare and analyze to prevent conveyor accidents. In addition, we propose extension of safety certification for full code switch, establishment of safety inspection standard, and improvement of working method regulation through actual working condition investigation. It can be used as a basis for revising the occupational safety and health regulation and related notices, and thus contributing to enhancing the safe atmosphere of the conveyor business and improving the safety consciousness of the concerned persons.

• Journal of the Korean Institute of Navigation
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• v.20 no.4
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• pp.7-44
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• 1996

The purpose of this study is to develop the training programme for VTS operators in Korea. The methodology used are literature and questionnaire survey. The literature, proceedings of international symposia and letters from Canada, USA, Japan and other countries were properly used and analyzed in order to compare their contents. Through the results of this study, I proposed the basic training programme for VTS operators in Korea as followings. First, the number and level of Korean VTS should be properly decided. Second, the training organization and staff should be built and appointed. Third, the VTS trainee should selected, and the training level & period should be established according to their qualification and experience. Fourth, the training should be acted by the VTS training curriculum. Fifth, The VTS operator certificate should be issued through proper test. This paper concluded as followings through the analysis of the questionnaire regarding to VTS training programme in Korea. First, the proposed curriculum were properly constructed and the independence among them was existed through the reliability and correlation analysis. Second, the difference of the curriculum importance among the questionnaire group was nearly not found through the Analysis of Variance(ANOVA). Third, the required days per each curriculum was limited to maximum 5days.

• KIEAE Journal
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• v.9 no.1
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• pp.69-76
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• 2009

The use of natural light can improve the quality of indoor environment and also occupants health. In recent years, with an increasing awareness of sustainable development, various innovative methods of integrating daylight into the building have been developed. One such device is the light pipe system. The light pipes are innovative daylighting system that allow the transmission of daylight into the hard-to-reach indoor space. The system consist of mainly three parts. First, a top collector which is mounted on the outside of the roof and gathers skylight and sunlight. Second, light-reflective tube which is coated with highly reflective mirror finish material to transmit the daylight into the diffuser. Third, a diffuser which is installed on the ceiling in the room and spread the daylight into the room. Light pipes have been widely used and researched in many countries such as Australia, America, Canada and Britain. However, despite the significant daylight potential, little work have been carried out in Korea compare to the other countries. In this study, recent lighting technology and application of light pipe system in both Korea and other countries have been compared. For the results, the benefits of each light pipe system and suitable application in Korea is also discussed.

• Ocean and Polar Research
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• v.29 no.4
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• pp.319-326
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• 2007

Coastal marine ecosystems continue to suffer unrelenting pressures from human population growth, increased development, and climate change. Moreover, these systems' capacity for self-repair is declining with such increases in anthropogenic production of various pollutants. What is the present health status or condition of the coastal ecosystem? If our coastal areas are unhealthy, which conditions are considered serious? To answer such questions, the United States, Canada, and Australia are currently assessing coastal ecosystem health using systematic monitoring programs as well as identifying and implementing management plans to improve the health of degraded coastal ecosystems. To evaluate marine environments, Korea is currently using a limited number of factors to estimate water quality. In fact, we are ill-prepared for assessing coastal ecosystem health because no biologically specific criteria are in place to measure the responses to various pollutants. We should select ecosystem-specific indicators from physicochemical stressors and evaluate the subsequent biological responses within each ecosystem. Furthermore, a set of practical indicators should be generated by considering the characteristics and uses of a local coastal area and the key issues at hand. The values of indicators should be presented as indices that allow understanding by the general public as well as by practitioners, policy makers, environmental managers and other stakeholders.

• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.523-527
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• 2012

Silicon carbide (SiC) has recently drawn an enormous amount of industrial interest due to its useful mechanical properties, such as its thermal resistance, abrasion resistance and thermal conductivity at high temperatures. In this study, RF thermal plasma (PL-35 Induction Plasma, Tekna CO., Canada) was utilized for the synthesis of high-purity SiC powder from an organic precursor (hexamethyldisilazane, vinyltrimethoxysilane). It was found that the SiC powders obtained by the RF thermal plasma treatment included free carbon and amorphous silica ($SiO_2$). The SiC powders were further purified by a thermal treatment and a HF treatment, resulting in high-purity SiC nano-powder. The particle diameter of the synthesized SiC powder was less than 30 nm. Detailed properties of the microstructure, phase composition, and free carbon content were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), a thermogravimetric (TG) analysis, according to the and Brunauer-Emmett-Teller (BET) specific surface area from N2 isotherms at 77 K.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4042-4051
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• 2021

In this work, we applied a multilevel modeling technique to estimate the diametral creep in the pressure tubes of Korean Canada Deuterium Uranium (CANDU) units. Data accumulated from in-service inspections were used to develop the model. To confirm the strength of the multilevel models, a 2-level multilevel model considering the relationship between channels for a CANDU unit was compared with existing linear models. The multilevel model exhibited a very robust prediction accuracy compared to the linear models with different data pooling methods. A 3-level multilevel model, which considered individual bundles, channels, and units, was also implemented. The influence of the channel installation direction was incorporated into the three-stage multilevel model. For channels that were previously measured, the developed 3-level multilevel model exhibited a very good predictive power, and the prediction interval was very narrow. However, for channels that had never been measured before, the prediction interval widened considerably. This model can be sufficiently improved by the accumulation of more data and can be applied to other CANDU units.

• Journal of Information Technology Services
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• v.19 no.2
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• pp.93-107
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• 2020

Recently, artificial intelligence (AI) technologies has been widely used in various fields such as finance, and distribution. Accordingly, Korea has also announced its AI R&D strategy for the realization of i-Korea 4.0 in May 2018. However, Korea's AI technology is inferior to major competitors such as the US, Canada, and Japan Therefore, in order to cope with the 4th industrial revolution, it is necessary to allocate AI R&D budgets efficiently through selection and concentration so as to gain competitive advantage under a limited budget. In this study, the importance of each AI technology was evaluated in multi-dimensional way through the questionnaire of expert group using the evaluation index derived from the literature review From the results of this study, we draw the following implication. In order to successfully establish the AI technology development strategies, it is necessary to prioritize the cognitive computing technology that has great market growth potential, ripple effect of technology development, and the urgency of technology development according to the principle of selection and concentration. To this end, it is necessary to find creative ideas, manage assessments, converge multidisciplinary systems and strengthen core competencies. In addition, since AI technology has a large impact on socioeconomic development, it is necessary to comprehensively grasp and manage scientific and technological regulations in order to systematically promote AI technology development.