• 한국약용작물학회지
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• 제12권5호
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• pp.378-383
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• 2004

Scopolamine and hyoscyamine are important anticholinergic compounds. To increase the productivity, we have selected various elicitors and developed culture system using a bubble column bioreactor (BCB). As the same manner of elicitation in flask cultures, the elicitors were introduced into BCB cultures and the productivity was investigated. Except the bacterial elicitor of Staphyllococcus aureus, the elicitors inhibited hyoscyamine production. In scopolamine production, the elicitors revealed different responses from the results obtained in flask cultures. The elicitors of KCl and Candida albicans less increased the production than flask cultures. However, methyl jasmonate and S. aureus showed stronger positive effects on tropane alkaloid production. In particular, S. aureus was the most effective elicitor on scopolamine production and the elicitor resulted in the highly increased production, approximately 10 times higher than the control culture.

• 한국직업건강간호학회지
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• 제27권2호
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• pp.121-130
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• 2018

Purpose: The purpose of this study was to investigate the effects of major health issues and job stress on presenteeism among clinical nurses. Methods: The investigator conducted a survey on 226 clinical nurses at a general hospital in Seoul from March 3 to April 15, 2017, and analyzed their responses. Results: The findings showed that job stress did not have a significant effect on the nurses' presenteeism. Fatigue (t=3.55,p<.001) impacted job loss, one of the subcategories of presenteeism, with an explanatory power of 12.1%. Premenstrual syndrome (t=-2.67,p=.008) and fatigue (t=-2.46,p=.015) affected perceived productivity with an explanatory power of 23.6%. Conclusion: Based on these findings, the study highlighted the need for effective management programs to tackle fatigue and premenstrual syndrome among clinical nurses' major health issues in order to reduce their productivity loss.

• 한국초지조사료학회지
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• 제17권1호
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• pp.75-81
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• 1997

This study was wnducte to investigate the effects of treatment level and seasons of sluny hm bovine feces on the productivity of rye, N efficiency and improvement of soil fertility under the Korean climate condition. The results obtained fiom this study summarized as follows ; 1. The highest dry matter yield of rye was obtained in the partial fertilization of sluny in spring or autumn. There is no differences of dry matter yield between spring and autumn application. 2. With increasing the amount of slurry-N, the dry matter yield of rye was signigicantly increased up to 100Kg sluny Nha. As the level of slurry-N rises above about 100Kg N/ha, the maximal yield of dry matter was unchanged or declined. 3. As the level of sluny fertilization rises, the crude protein content of rye increases significantly. However the contents of crude protein was less affected by the application seasons. 4. The amount of nitrogen which produced 6om rye is dependent upon the level of slurry-N. The highest nitrogen yield of rye was obtained by the partial fertilization of sluny-N. 5. The season or amount of slurry treatments did not affect the organic matter content in soil. N-content in soil was the lowest by the partial fertilization of slurry in spring or autumn. However, N-content was increased with the higher level of sluny-N.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1316-1323
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• 2017

Geosmin and 2-methylisoborneol (2-MIB), responsible for earthy or musty smell, are a major concern for safe drinking water supplies. This study investigated the effects of environmental factors on odorous compound production and cell growth in cyanobacterial strains. Anabaena sp. FACHB-1384, a 2-MIB producer, was sensitive to low temperature (<$20^{\circ}C$). However, geosmin producers, Anabaena sp. Chusori and Anabaena sp. NIER, were sensitive to high light intensity (>$100{\mu}mol/m^2/sec$), but not to low temperature. Geosmin concentrations increased under higher nitrate concentrations, being linearly proportional to cell density. A P-limited chemostat showed that P-stress decreased the geosmin productivity and extracellular geosmin amount per cell in Anabaena sp. NIER. However, only 2-MIB productivity was reduced in Planktothrix sp. FACHB-1374 under P-limitation. The extracellular 2-MIB amount per cell remained constant at all dilution rates. In conclusion, high light intensity and P-stress can contribute to the lower incidence of geosmin, whereas 2-MIB reduction could be attainable at a lower temperature.

• 농업과학연구
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• 제21권1호
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• pp.67-80
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• 1994

Farm land is considered the most important production factor in farm production. Land is not only one of the most scarce resource but also the size of land holding is the key factor in determining the size of farm income in Korea. To increase farm productivity by accepting bio-chemical and mechnical technology, the qualitative improvement of farm land through land consolidation and on-farm development have been carried out by the Korean government. Land consolidation with water resource development makes possible the high-tech-capital intensive farming, internal expansion of farm land and hightening the rate of land intensity in connection with UR problems. This paper contained the present status of farm land base development, allocation of investment by types of farm land development and the econome-trical analysis on the effects of the investment on rice productivity during the past 27 years since 1965. The rate of irrigated paddy area had been increased from 42% in 1965 to 74% in 1991. Land consolidated area out of the total paddy area had been achieved 44.9% and the improved rate of poor drained paddy area was shown 43.5% in 1991. To carry out the above farm land base development projects, the government had procured financial budgets consisting of the G't subsidy, long term loan, foreign loan, the provincial G't subsidy, WFP counter fund and farmer's burden.

• 자원ㆍ환경경제연구
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• 제11권2호
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• pp.233-260
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• 2002

This paper tries to analyze the efficiency structure and regulatory effects in electric power industry by using total factor productivity and indices based on cost function method. This paper performed an empirical analysis on the efficiency improvement and optimal scale taking the cost aspect in electricity industry into account. By expanding the cost structure framework, this paper proposes the analytical method regarding the needs of technology regulation and presents the empirical results which can be verified. Hence, this work can play a key role in decision-making of the national power development and regulatory policy. The empirical result indicates that the electricity industry in Korea has been in the state of economies of scale until 1980s, However, due to sustained growth of power generation, economies of scale declined and subsided after 1980s and then diseconomies of scale is shown recent years. The analysis on the effect of technology regulation shows the national large-scale base-load power plant development-oriented policy until so far contributed substantial cost effect to the electricity industry. The empirical result indicates that the reserve requirement as one of means of technology regulation policy did not contribute to the economies of scale but positive effect on the total factor productivity in Korea.

• 유기물자원화
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• 제19권1호
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• pp.115-122
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• 2011

의류용 세탁세제와 샴푸와 같은 합성세제가 혼입된 먹이를 급이하였을 경우 줄지렁이 개체군의 산란률, 난포당 부화개체수 및 차세대 발육 유충수의 증가를 유발시켰으며, 산란된 난포의 부화율에는 영향을 미치지 않는 것으로 나타났다. 따라서 생태독성학적 측면에서 합성세제는 줄지렁이 개체군에 대해 독성 현상을 유발하지 않으며 가정에서 사용하는 합성세제는 하수슬러지를 지렁이에게 지속적으로 급이하였을 때 나타나는 지렁이 개체군 소멸현상의 직접적인 원인이 아닌 것으로 판단된다.

• 공업화학
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• 제33권2호
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• pp.222-228
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• 2022

As a possible feedstock for biodiesel, the marine green alga Tetraselmis sp. was cultivated under different conditions of phototrophic, mixotrophic and heterotrophic cultures. Glycerol, a byproduct from biodiesel production process, was used as the carbon source of mixotrophic and heterotrophic culture. The effects of glycerol supply and nitrate-repletion were compared for different trophic conditions. Mixotrophic cultivation exhibited higher biomass productivity than that of phototrophic and heterotrophic cultivation. Maximum lipid productivity of 55.5 mg L^-1 d^-1 was obtained in the mixotrophic culture with 5 g L^-1 of glycerol and 8.8 mM of nitrate due to the enhancement of both biomass and lipid accumulation. The major fatty acid methyl esters (FAME) in the produced biodiesel were palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3). The degree of unsaturation was affected by different culture conditions. The biodiesel properties predicted by correlation equations based on the FAME profiles mostly complied with the specifications from the US, Europe and Korea, with the exception of the cold-filter plugging point (CFPP) criterion of Korea.

• Journal of Korea Trade
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• 제26권5호
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• pp.39-55
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• 2022

Purpose - This study empirically examines the effect of the Korean government export promotion program (EPP) on small and medium-sized enterprise (SMEs) export performance using firm-level data. Unlike most previous studies that investigated some specific samples of firms, this study analyzes a vast amount of SME data of the Korean Small and Medium Business Administration over the period 2005 to 2008. Design/methodology - An endogeneity problem arises when a firm's probability of being selected is correlated with the likelihood of successfully implementing EPPs. To control for the endogeneity of the EPPs in a relatively short-period sample, we employ 2-Stage Residual Inclusion (2SRI) RE-Tobit and bivariate Tobit procedure. Findings - Analyses show that Korean government EPPs have positive significant effects on SME exports. Empirical results also show that SME export activities are significantly encouraged by R&D investment and capital intensity, but not obviously by labor productivity. Originality/value - This study provides evidence that SME capital intensity, R&D investment, and the number of workers are significant determinants to SME exporting activities, whereas per worker labor cost and employee education are not. These results imply that even for SMEs, firm size is a major factor in promoting exporting activities.

• 한국직업건강간호학회지
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• 제32권4호
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• pp.152-163
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• 2023

Purpose: This study aimed to identify the effects of musculoskeletal symptoms and burden on presenteeism among nurses in a gastrointestinal endoscopy unit. Methods: This was an observational cross-sectional study. Data were collected through self-reported questionnaires administered to 140 nurses working in the gastrointestinal endoscopy unit of a hospital located in Busan metropolitan city. Results: The body part with the most musculoskeletal symptoms was the back (73.2%), and the most common musculoskeletal burden work was "when you have to stand or maintain the same posture for a long time in a lead apron protection clothes." The factors most related to work impairment were working hours, musculoskeletal symptoms, and musculoskeletal burden, with an explanatory power of 63.3%. Factors affecting perceived productivity were working hours and musculoskeletal symptoms, with an explanatory power of 29.2 %. Conclusion: To reduce work impairment and increase the perceived productivity of nurses in gastrointestinal endoscopy units, various programs and improved working environments are needed that can improve musculoskeletal symptoms and reduce musculoskeletal burden.