• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.251-260
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• 2011

In this study, the effect of natural jute fiber volume fraction on the bond characteristics of polyolefin based macro fiber in natural jute fiber reinforced cement composites, including bond strength, interface toughness, and microstructure analysis are presented. The experimental results on polyolefin based macro fiber pullout test of different conditions are reported. Natural jute fiber volume fractions ranging from 0.1% to 0.2% are used in the mix proportions. Pullout tests are conducted to measure the bond characteristics of polyolefin based macro fiber from natural jute fiber reinforced cement composites. Test results are found that the incorporation of natural jute fiber can effectively enhance the polyolefin based macro fiber-cement matrix interfacial properties. The bond strength and interface toughness between polyolefin based macro fiber and natural jute fiber reinforced cement composites increases with the volume fraction of natural jute fiber. The microstructural observation confirms the findings on the interface bond mechanism drawn from the fiber pullout test results.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.301-305
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• 1986

Fatty acid composition of domestic margarines (summer 12, winter 12 kinds) and foreign margarines (U.S.A. 4, Japan 8, Denmark 2 kinds) for home use were determined. The major fatty acids were palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) in all of the margarines. P/S ratios of winter products were $0.40{\sim}l.74$, those of summer products were $0.21{\sim}l.82$ in domestic margarines. Therefore degree of polyunsaturate in winter product was higher than that in summer product. P/S ratios of foreign margarines were $0.82{\sim}2.91$ irrespective of type.P/Sratios of stick and soft type in foreign margarines were similar as $0.82{\sim}2.59,\;0.90{\sim}2.67$, respectively Those of PUFA (polyunsaturated fatty acid) type and LFS (low fat spread) were 2.91, 2.70, respectively.

• Journal of the Korean Magnetics Society
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• v.16 no.1
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• pp.66-70
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• 2006

Magnetite nanoparticles, which have been extensively used in many fields, were encapsulated with a natural polymer, chitosan, to improve their biocompatibility. We have synthesized magnetite $(Fe_3C_4)$ nanoparticles using chemical coprecipitation technique with sodium oleate as surfactant. Nanoparticle size can be varied from 1.2 to 7.4nm by controlling the sodium oleate concentration. Magnetite phase nanoparticles could be observed from X-ray diffraction. Magnetic colloid suspensions containing particles with sodium oleate and chitosan have been prepared. High magnetic property chitosan-microsphere particles were prepared from oleate-coated magnetite suspension using spray method. The surftce, and tile morphology of the magnetic chitosan microsphere particles were characterized using optical microscope and scanning electron microscope. Magnetic hysteresis measurement were performed using a superconducting quantum interference device (SQUID) magnetometer at room temperature to investigate the magnetic properties of the chitosan microspheres including magnetite nanoparticles. The SQUID measurements revealed superparamagnetism of nanoparticles.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.68-74
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• 2014

Scientific study has investigated the body condition differences by habitat characteristics in larvae Korea salamander (Hynobius leechii) from March to April in 2012. To examine the sensitivity of external environment (predation risk), we divided two groups according to habitat characteristic; 1) Permanent pond and 2) Temporary pond. Howere, each larva was measured by head width at the level of the eye (HWE), largest head width (LHW) and snout-vent length, and we calculated the ratio of the head size by dividing HWE/LHW. As a result, larvae were larger in permanent pond group, had a faster growth rate than in temporary pond group. When exposed to the predator, larvae in permanent pond were smaller HWE/LHW than larvae in permanent pond. Therefore, these results indicate larvae in temporary pond more sensitive to the external environment.

• Communications of Mathematical Education
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• v.24 no.1
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• pp.195-220
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• 2010

The magic square is one of the number arrangements and the sums of each row, column, and diagonal are all equal. The meaning of "方" is "Square". If we don't consider the condition of 'square' then is it possible any number arrangement? There are many special number arrangements such as "magic five number circle(緊五圖)", "magic six number circle(聚六圖)", "magic eight number circle(聚八圖)", "magic nine number circle(攢九圖)", "magic eight camp circle(八陣圖)", "magic nine camp circle(連環圖)" in the ancient Chinese mathematics books such as "楊輝算法", "算法統宗". Also, there is a very special and beautiful number arrangement Jisuguimoondo(地數龜文圖) in the mathematics book "Goosuryak(九數略)" written by Choi suk jung(崔錫鼎) in the Joseon Dynasty. In this study, we introduce a various number arrangements and their properties.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.257-264
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• 2019

This study was conducted to investigate the effect of 70% ethanol extract (DR) on the mast cell-mediated allergic contact dermatitis induced by dinitrofluorobenzene in BALB / c mice, which affects the cell activity by antigen in RBL-2H3 mast cells Respectively. The ethanol extracts of RBL-2H3 cells activated by DNP-HSA and anti-DNP IgE antibodies inhibited the secretion of ${\beta}$-hexosaminidase, histamine, and IL-4 and $TNF-{\alpha}$ Production was suppressed. In the DNFB-induced contact allergic dermatitis animal model, treatment with ethanol extract reduced ear swelling and inhibited serum histamine and IL-4 secretion, and DR treatment effectively prevented mast cell infiltration in dermatitis-induced areas. As a result, the ethanol extract may be used as a therapeutic agent for mast cell-mediated allergic diseases such as atopic dermatitis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.352-355
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• 2003

비자성이며 비전도성의 물리적 성질을 갖는 자연산 퀄쯔(quartz)와 용암석 스코리아를 대상으로 마그네타이징 처리를 하여 분석하였다. 마그네타이징 처리를 위하여 강력한 기계화학적 분쇄 반응을 시켰으며, 분쇄 반응시 알코올계의 솔벤트를 반응 용매로 사용하였다. 퀄쯔와 스코리아의 마그네타이징 처리에서 비교적 비중이 큰 퀄쯔의 경우와 비중이 작은 스코리아의 경우에도 분쇄된 분말이 물에 뜨는 것을 확인할 수 있으며, 친유성으로 기름에 대한 흡착 성질이 우수함을 확인하였다. 자연산 퀄쯔와 함께 스코리아를 바탕물질로 하여 기계-화학적 반응 기술로 고 분산성 흡착반응에 의한 고분자 물잘 생성을 유도하여 나노복합체를 제조하였다. 반응의 처리조건과 적용과정에 따라서 기계-화학적 반응을 통하여 얻어진 물질은 자기적 성질과 유전체 및 전기적 성질을 동시에 나타낸다. 부착성 융합 복합물질의 특징을 고려하여 시그니토마그네틱스(Segneto-magnetics)로 분류되는 합성분말은 특히 유류성분에 대하여 높은 흡착성을 가지며, 강한 자기적 성질을 띄는 10-50 nm 두께의 하나 또는 그 이상의 이질적 융합 화합물 층이 석영이나 수정체의 표면에 합성되어 특유의 자기, 전기적 성질을 나타낸다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.300-302
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• 2019

The mast, which is the highest structure in warships, as well as merchant ships, is mainly equipped with radars and navigation lights. Especially, due to the nature of the naval vessels that operate many communication equipment, various kinds of antennas such as communication antennas and TACAN for aircraft guiding are installed in the naval mast. In addition to the complex structure of the mast itself, the installed antenna is a factor that greatly increases the RCS. Therefore, the mast technology for reducing the RCS is being developed and applied in the United States and Europe.

• Journal of the Daesoon Academy of Sciences
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• v.16
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• pp.265-304
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• 2003

장례의식은 불교에서 가장 중요한 정기적인 의식들 중에 하나이다. 이러한 의식은 수도자나 죽은 사람들을 위해서 행해지고 있다. 그렇다고 장례의식의 목적이 죽은 사람들만을 위한 것이 아니라 근원적으로는 'saṃsāra'의 윤회로부터 완전한 해방을 구하는 모습을 의미한다. 티벳불교에서의 죽음은 두 가지를 의미를 인식한다. 하나는 열반으로 입적하는 것으로 다섯 가지에 완전히 융해되는 것을 뜻한다. 이러한 죽음은 더 이상의 '태어남'이 없다. 열반의 경지는 카르마 안에서 융해 되거나 평화를 얻은 경지인 것이다. 또 하나의 죽음은 카르마의 법칙에 의해서 통제 되거나 하나의 영혼이 열반 안으로 들어가기 전까지 순환적인 주기 안에서 지속적으로 반복되는 것이다. 카르마는 불교의 관례를 통해서 카르마의 힘은 없어질 수 있다고 할지라도 근본적으로 외부적인 간섭을 수행하지는 않는다. 즉 불교의 이념들은 각자의 노력을 통해 해방을 얻는 것을 가르치고 있다. 하지만 카르마의 경로가 식별하기 어려워 제의식의 효과나 수행의식을 통해 알아 볼 수밖에 없다. 여기서는 티벳불교에서 죽은 후의 몸을 적절히 배치하는 방법을 얻는 제의식이나 축제에 관심을 갖는 것이 아니라 이를 통한 실질적이고 복합적인 힘, 그리고 카르마적 흐름을 바꾸거나 심지어 없애버릴 수 있는 의식에 관심을 갖고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.427-428
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• 2023

최근 COVID - 19로 인하여 다양한 수업방식이 활성화됨에 따라 비대면 수업방식이 주목받고 있다. 컨텐츠에 대한 소비패턴 변화와 가상융합기술이 발전함에 따라 해결책으로 메타버스가 대두되었으며 다양한 플랫폼을 지원하고 사용자가 가장 많은 마인크래프트 이용하였다. 마인크래프트는 사용자의 자유도가 높은 샌드박스 형식의 게임이다. 마인크래프트를 활용하여 메타버스 내에서 실시간 수업, 체육대회 등 실제와 유사한 활동을 바탕으로 구현함으로써 보다 친근한 메타버스를 제작하였다.