• Journal of the Korea Concrete Institute
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• v.16 no.4 s.82
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• pp.529-539
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• 2004

The corrosion of steel rebars has been the major cause of reinforced concrete deterioration. FRP(Fiber-reinforced polymer) rebar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, FRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. Therefore, the USA, Japan, Canada, UK. etc are using environmental reduction factor. Although difference design guidelines were drawn in many, including USA, Japan, Canada, UK etc, recommendations and coefficients that could take into account the long-term behavior of FRP reinforcement were not well defined. This study focuses on recommendation of environmental reduction factor of FRP rebar. Environment reduction factor were decided using durability test result. FRP rebars were subjected to twelve type of exposure conditions including alkaline solution, acid solution, salt solution and deionized water etc. The water absorption behavior was observed by means of simple gravimetric measurements and durability properties were investigated by performing tensile, compressive and short beam tests. Based on the experimental result, environmental reduction factor of hybrid FRP rebar(A), and (C) and CFRP rebar was decided as 0.85. Also, hybrid FRP rebar(B) and GFRP rebar were decided as 0.7 for the environmental reduction factor

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.177-182
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• 2008

The Gemological characteristics of B.C. jade from Cassiar Mine, British Colombia, Canada, have been investigated, using polarizing microscopy, Mohs' hardness, refractive index and density measurements, X-ray powder diffraction, X-ray fluorescence spectrometry, ICP-MS, Infrared absorption spectrometry, and DTA/TGA. The B.C. jade is deeply green (spinach peen or olive green) in color and is translucent. It shows a resinous or waxy luster. The principal mineral of the material is tremolite-actinolite solid solution and minor amount of Cr-garnet and unidentified opaque minerals are accompanied. Mohs' hardness value ($5.5{\sim}6$). refractive index (1.62), and specific gravity (3.01) are measured. It is very highly tough and shows hackly fracture. The high Fe content ($Fe_2O_3\;4.14{\sim}4.66\;wt%$) in B.C. jade is attributable to a deepening of green color of the material. The B.C. jade starts to dehydrate at v and dehydration is completed at $1000.8^{\circ}C$, transforming tremolite-actinolite solid solution to enstatite, diopside, quartz, and water in its place. This possible reaction is supported by the weight loss of B.C. jade (1.93 wt%) at $1000.8^{\circ}C$ indicated by TGA curve.

• Economic and Environmental Geology
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• v.22 no.2
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• pp.141-150
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• 1989

In order to make economic and geological evaluation of coal in Korea, proximate and ultimate analyses were carried out as well as coal petrological studies such as maceral analyses, vitrinite reflectance and sporinite fluorescence measurement. The coeffcient of correlation between each factor of both conventional utilization and coal petrological parameters were studied as in Table 5 and 6. Their conclusions were as follow: (1) for anthracite, the good parameters of coal rank are mean vitrinite reflectance, carbon content, hydrogen content and H/C atomic ratio: (2) for brown coal and sub-bituminous coal, the good parameters of coal rank are carbon content, calorific value, moisture content, hydrogen content, oxygen content and O/C atomic ratio as well as vitrinite reflectance and sporinite fluorescence. An attempt is made to infer the coalforming environment by utilization of coal petrological analyses and to make comparison of coal analyses with proximate and ultimate analyses throughout the island arc region including Japan, Philippine and Indonesia and continental region including USA, Canada and Australia. As a result, meceral composition of Paleozoic and Mesozoic anthracite are similar to that of the Paleozoic continental coals, which were formed under dry conditions or low water table, but the coalification degree suddenly increased during Daebo orogeny (middle Jurassic to lower Cretaceous). The Tertiary coal resembles those of Tertiary island arc region coal characterized by higher calorific value, volatile matter content and H/C atomic ratio and by the formation of coal under wet conditions or higher water table.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.3
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• pp.305-314
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• 1997

Nineteen clones of Jerusalem Artichoke (JA) from several countries were collected through the series of experiments about JA started in 1979. Collected clones were screened for adaptibility in Korea and showed introduction path way. The results about an ecological response of collected clones including flowering, tuberization, biomass production, sugar contents and grouping of collected clones for use of genetic material were as follows; 1. Nineteen clones collected were ffom Korea(2), Japan(l), USA(Z), Canada(2), France(4), Germany(7), and USSR(1). 2. Through the characteristics of top collected clones were divided to the types of branch-non branch, short and long plant height, and early and late maturity. Tuber characteristics were mainly grouped to the types of white skin color-violet skin color, clusters-single unit, round-elongate, and knotty-smooth. 3. Total sugar yields 6-om top at flowering time were 490 - 630kgl10a and 6-om the tuber were 420 -490 kg/ IOa through the high yielding clones. The top-high yielding clones were Mammoth French White, Fuseau 60, Nahodka, and JA3. The higher tuber yields were got from the clones of D- 19, Colombia, Bianka and Mammoth French White. 4. Collected clones were grouped to three and first group was characterized to early maturity and short plant height and second group to medium and finally, third group to late maturity and high plant height. 5. High yielding of top was 6-om the I group of early maturity and short plant height and high yielding of tuber h m III group of late maturity and high plant height.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.359-369
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• 2017

Water distribution systems supply drinking water to consumers' taps. Internal corrosion of metallic pipe used in drinking water distribution systems has reduced water quality and led to increased levels of toxic heavy metals such as lead, copper and nickel. These problems have been experienced to varying degrees by water utilities in many countries. North America has successfully managed and controlled pipe corrosion and corrosive water in water distribution system based on various policies, regulations and rules. Practical and engineering guidelines for evaluation of pipe corrosion and determination of treatment options are also provided to assist drinking water supplies. In addition, the corrosion mechanism in water distribution systems, such as the complex effects of physical and chemical parameters on the corrosion pipes has been improved to accurately predict corrosion rates of metallic pipes in actual water distribution systems. This paper reviews various regulations, policy statement, and treatment produces on controlling corrosion in drinking water distribution systems in US and Canada and then offers suggestion for management of corrosive water and pipe corrosion in drinking water distribution system in Korea.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3228-3232
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• 2010

Malachite green (MG) has been used world-widely in aquaculture as a parasiticide or fungicide. Although MG performed successfully, it has not been permitted for use in aquaculture from European Union, USA, and Canada because of its carcinogenicity and mutagenicity. We developed a sensitive and specific method to determine MG and its principal metabolite, leucomalachite green (LMG), respectively by isotope dilution liquid chromatography mass spectrometry (ID-LC/MS). To enhance the extraction recovery of MG and LMG from fish tissue, an additional step, saponification, was introduced in sample preparation process to remove fat in sample extract, which hampered the performance of SPE columns. The residue of MG and LMG in fish was analyzed using liquid chromatography mass spectrometry in the selected ion monitoring (SIM) mode by monitoring at m/z 329 and 334 for MG and $d_5$-MG and at m/z 331 and 337 for LMG and $^{13}C_6$-LMG, respectively. This method was validated by comparing with the value of the reference material provided by Laboratory Government Chemistry (LGC). The results agreed within the measurement uncertainty and the accuracy was much improved than the provided reference value by LGC.

• Journal of Research and Publication Ethics
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• v.2 no.1
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• pp.1-6
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• 2021

The aims of this study were to examine the causes and types of the most common and serious fraudulent authors among research misconduct, and to examine ways to reduce the mass production of unjust authors. In scientific research, it is universal and efficient to have multiple authors participate. This is because each author group consisting of a team has its own expertise, and most of them participate in research in a complementary way to maximize the research effect. However, the competition for achievements between researchers, the quantitative evaluation system of universities, and the social atmosphere of performance-oriented are tempting researchers to abandon research ethics. In this study, in relation to the research ethics of existing researchers, the contents of research ethics by a few countries such as United States, United Kingdom, Germany, Canada, Australia etc. and the situation in Korea was examined as well. In addition, the types and causes of domestic unfair authors in Korea were investigated intensively. In conclusion, in order to no longer produce unfair authors such as compulsory authors, honorary authors, mutually supported authors, and duplicate authors, which researchers unknowingly recognize as co-authors, reinforcement of research ethics education and national organization and system should be supported.

• Korean Medical Education Review
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• v.20 no.3
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• pp.128-134
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• 2018

Medical education, competency, and outcome-based medical education started as part of the basic medical education curriculum in advanced countries 20 years ago, and such an approach was adopted in residency training. General competency training is at the core of residency training in advanced countries, and it goes beyond competency and outcome-based training to the extent that in a milestone training system, competency development is expected and measured with set competency achievements at each level. Recently, for the purpose of ensuring that doctors uphold patient safety and fulfill their obligations, entrustable professional activities (EPA) were applied at the beginning of residency when doctors move away from clinical trials and start actual care. The adoption of EPA in all residency training curriculum has spread very rapidly in the United States, United Kingdom, and Canada. Presently, Korea lags behind other countries significantly as the adoption of competency and outcome-based medical education in residency training has just begun. It is time to identify the current state of the Korean residency training system, and then design and practice a well-established system with a long-term view based on cooperation across the whole medical industry.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.2
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• pp.32-39
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• 2007

Air Transportation industry becomes more competitive that the restriction on new access to market were eased and relaxed. Liberalization of international air transport will continue, via bilateral and multilateral process. Korea, Japan, and China have expanded enormously the economic trade and cultural exchange bilaterally in the Northeast Asia, they are acknowledging the importance and necessity of improved connection, it order to face effectively other regional blocks of US-Canada, NAFTA, ASEAN, CLMV. In particular, nobody denies that it is urgent to liberalize bilaterally the air transport in Northeast Asia for promoting reciprocal benefits and prosperity. Recently while open skies bilateral agreements was signed between Korea-China in June, 2006. The agreements processes are too heavily influenced by flag carriers; leading to capacity/market sharing between the bilateral carriers in most markets, against the interest of consumers and overall economic interest of the nation. For successful operation of Northeast Air Market, it is need to set up development strategy paradigm by creating cross-border sub-regional (Northeast Asian) open skies bloc as well as preparing and creating of LCCs operations.

• Journal of Astronomy and Space Sciences
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• v.31 no.2
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• pp.169-176
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• 2014

Since the operation of the King Sejong Station (KSS) started in Antarctic Peninsula in 1989, there have been continuous efforts to perform the observation for the upper atmosphere. The observations during the initial period of the station include Fabry-Perot Interferometer (FPI) and Michelson Interferometer for the mesosphere and thermosphere, which are no longer in operation. In 2002, in collaboration with York University, Canada, the Spectral Airglow Temperature Imager (SATI) was installed to observe the temperature in the mesosphere and lower thermosphere (MLT) region and it has still been producing the mesopause temperature data until present. The observation was extended by installing the meteor radar in 2007 to observe the neutral winds and temperature in the MLT region during the day and night in collaboration with Chungnam National University. We also installed the all sky camera in 2008 to observe the wave structures in the MLT region. All these observations are utilized to study on the physical characteristics of the MLT region and also on the wave phenomena such as the tide and gravity wave in the upper atmosphere over KSS that is well known for the strong gravity wave activity. In this article, brief introductions for the currently operating instruments at KSS will be presented with their applications for the study of the upper atmosphere.