• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.663-670
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• 2016

This paper analyzes the asymmetric pass-through effects of crude oil price changes on export prices in Korea's manufacturing sector using a nonlinear autoregressive distributed lag (NARDL) model. These pass-through effects are important for Korean companies that are highly dependent on exports. Because the effects differ by industry, eight sectors of the manufacturing industry were examined. The model is effective for separately testing the long-term and short-term differences between the export-price pass-through effects when crude oil prices increase and decrease. The estimation results show that there is positive pass-through to export prices as crude oil prices change, and there are asymmetric effects in some manufacturing sectors. Short-term asymmetries were detected in the export prices of five sectors that include general machinery and transport equipment, and significant long-term asymmetries were found for petroleum and coal products and for textile and leather products. The long-term export price of oil and coal products rose by 0.992% with a 1% increase in the oil price and fell by 0.977% with 1% decrease. Therefore, corporate strategies and government export policies should be established in accordance with these asymmetric pass-through effects.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.227-234
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• 2022

In this study, the rheological properties of cement paste composites applied with carbon-based nano-materials were experimental analyzed. Flow table and rheological properties, compressive strength were measured in the cement paste using graphene oxide asqueous solution and carbon nanotube aqueous solution. When carbon nano-materials was mixed in an aqueous solution, flow decreased and plastic viscosity and shear stress were increased. In particular, graphene oxide rapidly increased the plastic viscosity and shear stress. In the case of carbon nanotube aqueous solution, when less than 0.2 % was mixed, the increase rate was low compared to graphene oxide. This is because the specific surface area of graphene, which is in the form of a plate, is large. The compressive strength showed a small amount in strength increase when graphene mix, and CNT had a strength about 112 % of OPC. Carbon-based nanomaterials, is considered that CNT are suitable more to be used construction materials. However, extra studies on the surfactant to be used for mixing proportion and dispersion will be needed.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.174-179
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• 2015

For development a new anti-diabetic compound from edible mushroom, antihyperglycemic ${\alpha}$-glucosidase inhibitory activities of Pleurotus ostreatus, Pleurotus cornucopiae, Pleurotus salmoneostramineus, Pleurotus eryngii and Neolentinus lepideus were investigated on its water and ethanol extracts. ${\alpha}$-Glucosidase inhibitory activity of Neolentinus lepideus fruiting body showed the highest at 86.3% in the 95% ethanol extracts and water extract from Pleurotus cornucopiae was also higher at 48.5% among water extracts. Therefore, Neolentinus lepideus which showed very high ${\alpha}$-glucosidase inhibitory activity was selected as a new anti-diabetic agent-containing mushroom and the ${\alpha}$-glucosidase inhibitor was maximally extracted when treated with 95% ethanol at $30^{\circ}C$ for 48 hr. The ethanol extracts from Neolentinus lepideus fruiting body showed dosage-dependent hypoglycemic action after administration to 120 min in the SD-rat and streptozotocin-induced diabetic SD-rat.

• Journal of Digital Convergence
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• v.16 no.8
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• pp.19-26
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• 2018

In an effort to investigate the effects of chatbots on English listening and reading skills, 46 college students participated in the current study. Participants consisted of first-year students who enrolled in an English class at a university in South Korea. They were randomly divided into two groups: one experimental group (n=24) and one control group (n=22). During 16 weeks, the experimental group engaged in chats with a chatbot, named Elbot, while the control group did not. There were pre- and post-tests to confirm the effects of the chatbot usage. Major findings are as follows: First, participants in both groups significantly improved listening and reading skills. On the post-listening test, however, the experimental group showed more improvements. Their listening proficiency level improved from intermediate to advanced level after engaging in chat with the chatbot. Limitations and implications for theory and practice are discussed at the end.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.193.2-193.2
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• 2015

최근 3차원 반도체의 물질적인 한계를 극복하기 위해 2차원 전이금속 칼코게나이드(TMD)에 대한 연구가 활발히 진행되고 있다. 하지만 TMD 물질의 도핑 방법에 대한 수많은 연구에도 불구하고 대부분이 n채널 물질인 MoS2에 대한 것에 국한되어 있다. 게다가 이전의 TMD 도핑 기술 연구 결과는 채널이 도체화 될 정도의 매우 높은 농도의 도핑 현상만을 보여주었다. 이 연구에서 우리는 WSe2로 만든 p형 채널 트랜지스터에서 Octaecyltrichlorosilane(OTS)층의 농도 조절로 제어가 가능한 약한 농도의 p형 도핑기술을 보여준다. 이 p형 도핑 현상은 OTS의 메틸기(-CH3)그룹에 의한 양성 쌍극자모멘트가 WSe2내의 전자 농도를 낮추는데서 기인한다. 제어가 가능한 p형 도핑은 $2.1{\times}10^{11}cm^{-2}$ 사이에서 $5.2{\times}10^{11}cm^{-2}$로 degenerate되지 않은 정도로 WSe2 기반의 광, 전기적인 소자에서 적절한 농도로 최적화 될 수 있다. (도핑 정도에 따른 문턱전압 상승, 전류 on/off율 상승, 전계효과 이동도 상승, 광응답성 하락, 광검출성 하락) 또한 OTS에서 비롯한 p도핑 효과는 대기중에서 오랜시간이 지나도 작은 성능 변화만을 보여주며(60시간 후 18~34% 문턱전압 감소변화량) $120^{\circ}C$의 열처리를 통하여 저하된 성능이 거의 완벽하게 회복된다. 이 연구는 Raman 분광법과 전기적, 광학적 측정을 통하여 분석되었으며 OTS 도핑현상이 WSe2 박막의 두께와 무관함 또한 확인했다.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.163-166
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• 2011

For reduction of side effects by anti-fungal agents, a less toxic anti-fungal substance or a synergistic substance with a new mechanism is needed. The anti-yeast substance (AYS) originated from Rahnella aquatilis strain AY2000 is like to be a heterogeneous protein. The AYS inhibited the growth of Candida albicans in culture broth, and AYS-treated cells were arrested in each phase during cell cycle. Among AYS-treated cells, the population of the cells belonging to sub-G1 phase was not increased during cell cycle. Therefore, AYS has rather yeaststatic than yeastcidal effect to C. albicans. Moreover, with combination of itraconazole or fluconazole, AYS had a synergistic anti-yeast activity against Saccharomyces cerevisiae based on the analysis of fractional inhibitory concentration index.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.83-90
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• 2006

The NaCl contents of food waste composts made by various techniques known up to now were under the level of 1% by fresh weight basis. But these techniques has some problem that is environment pollution from treated water and high equipment cost. The application to agricultural land of food waste compost that is not sufficiently removed NaCl was considered to be improper due to salt accumulation in soils and plant growth inhibition by salt stress. The purpose of this study is to decompose NaCl in food waste compost using triple salt and this method is differ from existing chemical method. Also, reaction of NaCl with triple salt produced KCl that is basic material of potassium fertilizer. Moreover Also, there was temperature rise of average $5^{\circ}C$ as result that apply triple salt in food waste 600 ton in food wast composting productive capacity. Obvious odious smell reduction effect appeared pretreatment process and fermentation process with temperature rise and this is because triple salt activation of aerobe and removes odious smell cause material by salt content decrease effectively.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.28-30
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• 2009

이종접합태양전지에서 p a-Si:H/c-Si의 p a-Si:H의 증착 조건인 $H_2/SiH_4$ 비율, $B_2H_6$의 농도를 변화 시키며 실험하여 이 따라 계면 특성 변화를 연구하였다. pa-Si:H의 $H_2/SiH_4$ 비율이 상승할수록 carrier lifetime이 증가하다 다시 감소하는 경향을 나타내었다. 이는 $H_2/SiH_4$의 비율 중 효과적으로 웨이퍼표면을 효과적으로 passivation하는 지점이 있는 것으로 보인다. $B_2H_6$의 농도는 상승할수록 carrier lifetime이 줄어드는 경향을 보였다. $B_2H_6$에서 농도가 올라감에 웨이퍼 표면의 defect로 작용했을 것으로 생각된다. 이에서 몇몇의 조건으로 태양전지를 제작한 결과 $H_2/SiH_4$ 비율에 따라서는 carrier lifetime은 효율에 그 영향이 미미한 것으로 조사되었고, $B_2H_6$의 농도가 낮을수록 개방전압은 상승하는 결과를 얻어 도핑 농도가 효율에 직접적인 형향을 주는 것으로 나타났다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1363-1368
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• 2014

The physiological activities of cultivated Korean blue mussel (Mytilus edulis) and New Zealand green-lipped mussel (Perna canaliculus) were analyzed and compared. Both hot water extracts of blue mussel flesh (BMF) and green-lipped mussel flesh (GMF) showed increased activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). BMF showed increased ADH and slightly decreased ALDH activities compared to GMF. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity of BMF was higher than that of GMF at the same concentration. BMF and GMF showed similar inhibitory activity against angiotensin converting enzyme at a concentration of 30 mg/mL. These results suggest that cultivated Korean blue mussel has similar physiological activity with New Zealand green-lipped mussel.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.242-248
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• 1983

The effects of light source, plant growth regulators (GA, BA, ABA), and sodium hypochlorite (4% Cl, SH) on germination of 'G rand Rapid' lettuce (Lactuca sativa L.) seed were studied. Seed did not germinate under the conditions of dark and blue light. The treatment of GA or BA did not promote on germination under dark or blue light. The germination percentage under red light was very high, it was similar to the condition of white light. ABA inhibited lettuce seed germination. Although ABA was treated, BA 10ppm treatment was moderately effective under white light condition and BA 10ppm or 50ppm combined with GA 50ppm were also effective on seed germination under dark condition. Presoaking in sodium hypochlorite solution induced germination of lettuce seed in any condition of dark or white light. The optimum presoaking time in sodium hypochlorite solution was twenty min.