• 기술혁신연구
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• 제25권3호
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• pp.83-113
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• 2017

본 연구는 1991년~2005년의 기간 동안 한국 특허청에 출원된 내국인 특허의 공동발명자료를 이용해 네트워크 특성 변수들의 '연도별 x 발명자별' 패널 자료를 구축하고, 이 자료를 사용하여 발명자 네트워크의 특성변수들이 발명자의 특허생산성에 미치는 효과를 패널 회귀분석하였으며, 다음과 같은 결과를 얻었다. 첫째 네트워크상의 강한 연계는 발명자 생산성에 정(+)의 효과를 미치는 것으로 나타났다. 둘째, 네트워크내 중심에 있는 발명자일수록 특허생산성이 높았다. 셋째, 네트워크의 기술적 다양성은 발명자의 특허생산성을 높이는 요인이다. 넷째, 발명자 네트워크의 질이 좋을수록 그 네트워크에 속한 발명자의 특허생산성이 높아진다. 다섯째, 네트워크의 크기가 클수록 네트워크내 발명자의 특허생산성이 높다. 여섯째, 네트워크에만 의존하는 발명자의 특허생산성은 상대적으로 낮았지만, 네트워크에 속하지 않은 발명자의 특허생산성은 오히려 높았다. 일곱째, 네트워크 변수들의 효과는 지역별로 차이가 있다. 여덟째, 지리적 경계가 약화되고 있지만, 네트워크 효과의 지역적 차이는 줄어들지 않고 있다.

• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.2009-2018
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• 2018

Leuconostoc mesenteroides can be used to produce mannitol by fermentation, but the mannitol productivity is not high. Therefore, in this study we modified the chromosome of Leuconostoc mesenteroides by genetic methods to obtain high-yield strains for mannitol production. In this study, gene knock-out strains and gene knock-in strains were constructed by a two-step homologous recombination method. The mannitol productivity of the pat gene (which encodes phosphate acetyltransferase) deletion strain (${\Delta}pat::amy$), the fk gene (which encodes fructokinase) deletion strain (${\Delta}fk::amy$) and the stpk gene (which encodes serine-threonine protein kinase) deletion strain (${\Delta}stpk::amy$) were all increased compared to the wild type, and the productivity of mannitol for each strain was 84.8%, 83.5% and 84.1%, respectively. The mannitol productivity of the mdh gene (which encodes mannitol dehydrogenase) knock-in strains (${\Delta}pat::mdh$, ${\Delta}fk::mdh$ and ${\Delta}stpk::mdh$) was increased to a higher level than that of the single-gene deletion strains, and the productivity of mannitol for each was 96.5%, 88% and 93.2%, respectively. The multi-mutant strain ${\Delta}dts{\Delta}ldh{\Delta}pat::mdh{\Delta}stpk::mdh{\Delta}fk::mdh$ had mannitol productivity of 97.3%. This work shows that multi-gene knock-out and gene knock-in strains have the greatest impact on mannitol production, with mannitol productivity of 97.3% and an increase of 24.7% over wild type. This study used the methods of gene knock-out and gene knock-in to genetically modify the chromosome of Leuconostoc mesenteroides. It is of great significance that we increased the ability of Leuconostoc mesenteroides to produce mannitol and revealed its broad development prospects.

• 유통과학연구
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• 제13권2호
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• pp.45-53
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• 2015

Purpose - This study strives to discern trends in research productivity in the Journal of Consumer Behavior. It will identify prolific authors and institutions in articles over ten years (2004-2013). Research design, data, and methodology - The Journal of Consumer Behavior was chosen and articles over ten years were analyzed. Research productivity was determined by categorizing the data into four themes: number of authors per article, author affiliated institutions, a list of prolific authors over a ten-year period, and author-affiliated countries. Results - Authors have a propensity to collaborate on a research paper, yielding a high frequency of articles with two or three authors in a single publication. In addition, author and institution productivity was highest in North America and Europe. Conclusions - The research productivity of the Journal of Consumer Behavior is unprecedented. The trends and insights from this study will allow academics in the area of consumer behavior to observe leading authors and institutions. Moreover, speculations about the leading countries and institutions, not to mention top prolific authors in consumer behavior, will be elucidated in this study.

• ALGAE
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• 제29권3호
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• pp.217-225
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• 2014

Land-based seaweed (Gracilaria) cultivation systems may provide products with high quality and biosafety for human consumption, as well as for other high value applications. However, a limitation for this land based system is high management costs. The objective of this study was to determine if the management costs for Gracilaria cultivation can be reduced without a decrease in productivity by using $CO_2$ injection along with a high stocking density and high photosynthetically active radiation (PAR), and commercially available fertilizers. When Gracilaria tikvahiae was cultivated at a high stocking density and high PAR, coupled with $CO_2$ enhancement, the productivity was significantly higher than that at a lower stocking density, low light without $CO_2$ injection. We also found that G. tikvahiae grown in a medium of commercially available fertilizer (Jack's Special, JS) showed a similar growth rate and productivity to that grown in von Stosch's enriched (VSE) seawater, while the cost for JS media is only 2% of the cost for VSE. These results suggest that $CO_2$ injection and commercial fertilizer may be a potential way to provide sustainability in land-based Gracilaria cultivation systems.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.196-201
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• 1997

The biggest challenge facing today's manufacturing industry is better quality and high productivit. From an economic point of view, productivity is the most important parameter, as high productivity will reduce the cost. However, the customers of today are not only cost concerned, but also quality conscious. So high accuracy levels should also be achieved in the manufacturing process. The aim of this paper is to get a comprehensive understanding of its machinability properties and to investigate the relationship between cutting conditions and surface roughness for Ball End Mill cutting process so as to enhance its practical application.

• Journal of Ecology and Environment
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• 제33권1호
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• pp.59-65
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• 2010

Because seagrass production significantly contributes to the biodiversity and production of coastal and estuarine ecosystems, accurate estimation of seagrass productivity is a critical step toward understanding the ecological roles of seagrass in these ecosystems. To develop an accurate and effective method of measuring seagrass productivity, we estimated leaf productivity of eelgrass (Zostera marina) on the southern coast of Korea using three methods, the conventional leaf marking method, the elongation-mass method (Short '87 method), and the plastochrone method. In each season, shoots were pierced through the bundle sheath using a hypodermic needle and were collected after 2-4 weeks had elapsed to estimate their productivity. The leaf elongation and the leaf plastochrone intervals varied significantly among seasons. On an annual basis, the conventional leaf marking method showed the lowest leaf productivity estimates compared to the elongation-mass method and the plastochrone method, suggesting that the conventional leaf marking method underestimated leaf productivity as it ignored leaf maturation processes and new leaf growth within the sheath. Since the elongation-mass method considered leaf maturation processes, this method produced higher leaf productivity estimates than the conventional leaf marking method. On an annual basis, the plastochrone method produced the highest leaf productivity estimates. Below-ground productivity, which can be easily estimated using the plastochrone method, ranged between 3.29 and 5.73 (mg dry weight $shoot^{-1}\;day^{-1}$) and accounted for about 17.8% to 30.3% of total productivity. Because of the high contributions of below-ground productivity to total seagrass production, we suggest that the plastochrone method is an effective and simple technique for assessing both above- and below-ground productivities.

• The Korean Journal of Ecology
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• 제6권2호
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• pp.114-127
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• 1983

The production and productivity of $C_3 and C_4$ type plants in Korea was studcied In the areas, in which the summer temperature is above $30^{\circ}C,;C_3$ type plants showed“M” type productivity curves exhibiting two peaks in spring and autumn, and C4 type plants showd “Bell” type productivity curves which show one peak in summer(Figs. 1,2,3,4,5). From the result of researching the standing crop of $C_3 and C_4$type plants dcuring August and September in which the standing crop reaches the highest peak, the dominant plants in the natural grass vegetation were almost all of $C_4$ type plants, showing the high standing crop, while the standing crop of $C_3$ type plants shows its high peak in the humid areas, riversides and dams.

• 한국항해항만학회지
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• 제30권8호
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• pp.691-697
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• 2006

본 연구의 목적은 기존의 컨테이너터미널 이송차량의 기술대안을 분석하여 터미널 생산성을 높일 수 있는 고생산성이송차량 모델을 개발하는 것이다. 대안 개발을 위해 YT(Yard Tractor), S/C(Straddle Carrier), SHC(Shuttle Carrier), AGV(Automated Guided Vehicle) 등의 이송차량에 대한 기술적 사양을 분석하며, 이송차량의 기술단계별 세대를 분류하기 위하여 운영현황과 성능을 조사한다. 본 연구에서 제시하는 이송차량의 개발 대안은 향후 고생산성의 진보된 컨테이너 터미널에 유용하게 활용될 것이다.

• 한국축산시설환경학회지
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• 제20권2호
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• pp.63-68
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• 2014

Environmental heat stress by global warming has a severe effect on the productivity of livestock and, in particular, on that of dairy cattle. Heat stress during high temperature environment directly and indirectly affects milk yield, milk quality and physiological response. This study was conducted to investigate the effects of heat stress on productivity and physiological responses of livestock. Temperature-humidity data logger were established inside the feedlot for measuring real time changes in the feedlot environment. Milk was collected every day for analysing the productivity of dairy cattle. Blood sample and respiration of dairy cattle were collected once in a week for investigating the physiological response factors. Blood component concentration associated with lipolysis metabolism and milk production showed change during tropical night period. Temperature humidity index (THI) of a specific location inside the feedlot showed continuously high levels.

• 무역학회지
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• 제46권3호
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• pp.45-63
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• 2021

This paper investigates the effects of China's participation in global value chains (GVC) on the productivities focusing on the manufacturing industries. In this study, several indicators of participation in global value chains were used. These include GVC participation, forward GVC participation, backward GVC participation and GVC position index. In particular, we used the data obtained from 18 manufacturing industries in China during 15 years from 2000 to 2014. The main results of the analysis are as follows. First, the higher the degree of total participation in GVC, the higher the productivity. This means that with the increase in exports and imports of intermediate goods, productivity has increased through technology spillover effects or competition effects, and so on. Second, the backward participation does not increase the productivities significantly while forward participation leads higher productivity. Third, the productivity improvement effects of GVC participation was larger in the high-tech industries than in the low-tech industries. These results show that GVC participation was helpful for the economic growth of China and the efforts for moving toward upstream production stage in GVC is necessary for the improvement of international competitiveness in Chinese manufacturing industry.