• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2019.08a
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• pp.150-150
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• 2019

• Ocean and Polar Research
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• v.23 no.4
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• pp.379-388
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• 2001

Ch1 a abundance, Ch1 a-specific productivity and phytoplankton growth rate in each size fraction (pico, $<2{\mu}m$; nano, $2-10{\mu}m$; micro, > $10{\mu}m$) in the waters around the South Shetland Islands (Ant-arctic Peninsula Area) were analysed. Although Ch1 a-specific productivity and growth rate were highest in micro-size fractions, ChI a abundance was highest in pico-size fractions. Selective removal of nano- and micro-size phytoplankton especially by krill and salp grazing, but not limitation of phytoplankton growth, seemed to be the major reason to explain this miss match between productivity and abundance of the phytoplankton community.

• East Asian Journal of Business Economics (EAJBE)
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• v.10 no.4
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• pp.55-64
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• 2022

Purpose - Corporate reading management requires employees capable of doing their job since employee performance is crucial to the firm's profitability. The objective of this study was to evaluate the positive effects of corporate reading management on employee management. It focuses on factors increasing employee productivity and the impacts corporate management brings about on the overall productivity of any kind of company. Research design, Data, and methodology - The current authors have investigated and conducted the qualitative content analysis (QCA) to obtain the adequate textual dataset in the prior and current literature. One of the primary benefits of doing research using content analysis is that it enables the researcher to employ a combination of qualitative and quantitative research methodologies. Result - Based on the review of the prior literature, the present authors found that there are four corporate reading management solutions to improve employee performance, following those instructions - A. Increased Motivation and Productivity, B. Employee Development, C. Businesses' Objective Alignment, and D. Improved Work Environment. Conclusion - This study addressed and figured out different factors that reading corporate can apply to influence employee performance, thus increasing the company's productivity. Future research should evaluate the adverse effects businesses might face from unfavorable working environments. The research also needed to address how ethics influences employee performance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.112-126
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• 1991

The atmospheric carbon dioxide concentration is ever-increasing and expected to reach about 600 ppmv some time during next century. Such an increase of $CO_2$ may cause a warming of the earth's surface of 1.5 to 4.5$^{\circ}C$, resulting in great changes in natural and agricultural ecosystems. The climatic scenario under doubled $CO_2$ projected by general circulation model of Goddard Institute for Space Studies(GISS) was adopted to evaluate the potential impact of climate change on agroclimatic resources, net primary productivity and rice productivity in Korea. The annual mean temperature was expected to rise by 3.5 to 4.$0^{\circ}C$ and the annual precipitation to vary by -5 to 20% as compared to current normal climate (1951 to 1980), resulting in the increase of possible duration of crop growth(days above 15$^{\circ}C$ in daily mean temperature) by 30 to 50 days and of effective accumulated temperature(EAT=∑Ti, Ti$\geq$1$0^{\circ}C$) by 1200 to 150$0^{\circ}C$. day which roughly corresponds to the shift of its isopleth northward by 300 to 400 km and by 600 to 700 m in altitude. The hydrological condition evaluated by radiative dryness index (RDI =Rn/ $\ell$P) is presumed to change slightly. The net primary productivity under the 2$\times$$CO_2$ climate was estimated to decrease by 3 to 4% when calculated without considering the photosynthesis stimulation due to $CO_2$ enrichment. Empirical crop-weather model was constructed for national rice yield prediction. The rice yields predicted by this model under 2 $\times$ $CO_2$ climatic scenario at the technological level of 1987 were lower by 34-43% than those under current normal climate. The parameters of MACROS, a dynamic simulation model from IRRI, were modified to simulate the growth and development of Korean rice cultivars under current and doubled $CO_2$ climatic condition. When simulated starting seedling emergence of May 10, the rice yield of Hwaseongbyeo(medium maturity) under 2 $\times$ $CO_2$ climate in Suwon showed 37% reduction compared to that under current normal climate. The yield reduction was ascribable mainly to the shortening of vegetative and ripening period due to accelerated development by higher temperature. Any simulated yields when shifted emergence date from April 10 to July 10 with Hwaseongbyeo (medium maturity) and Palgeum (late maturity) under 2 $\times$ $CO_2$ climate did not exceed the yield of Hwaseongbyeo simulated at seedling emergence on May 10 under current climate. The imaginary variety, having the same characteristics as those of Hwaseongbyeo except growth duration of 100 days from seedling emergence to heading, showed 4% increase in yield when simulated at seedling emergence on May 25 producing the highest yield. The simulation revealed that grain yields of rice increase to a greater extent under 2$\times$ $CO_2$-doubled condition than under current atmospheric $CO_2$ concentration as the plant type becomes more erect.

• Journal of Wetlands Research
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• v.9 no.2
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• pp.33-43
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• 2007

Distribution area, actual vegetation map, standing crop biomass, relative growth, and primary productivity of Salix spp.were investigated to provide the basic data necessary for conservation and ecotechnological application of Salix community in the Upo wetland, Changryeong County, Gyeongsangnamdo Province, Korea from April 2005 to April 2006. 1. Among seven Salix species, the dominant species was S. nipponica and S. glandulosa was subdominant. There were six kinds of Salix communities such as S. nipponica, S. glandulosa, S. koreensis, S. nipponica-S. glandulosa, S. glandulosa-S. nipponica, and S. nipponica-S. koreensis. 2. Distribution area of S. nipponica community was largest as 28.46 ha among Salix communities and those of S. nipponica-S. glandulosa community, S. glandulosa-S. nipponica community, S. nipponica-S. koreensis community, S. glandulosa community, and S. koreensis community were 6.12 ha, 6.12 ha, 2.92 ha, 1.86 ha, and 0.81 ha, respectively. 3. The tree age, tree height, and DBH of S. nipponica were 5~13year, 4.1~7.2 m, and 3.0~14.0 cm and those of S. glandulosa were 2~36year, 3.5~10.1 m, and 3.2~26.0 cm, respectively. 4. The standing crop of S. nipponica was 408 ton and that of S. glandulosa was 336 ton in the study area. 5. The productivity of S. nipponica was $235g\;m^{-2}yr^{-1}$ and the annual production was 86.4 ton, and those of S. glandulosa were $1,006g\;m^{-2}yr^{-1}$ and 80.3 ton in the study area.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.505-513
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• 1995

The major factors affecting productivity on daily farms in Queensland, Australia, were determined using the stepwise linear regression approach. The data were obtained from a survey conducted on the total population of daily farms in Queensland in 1987. These data were divided into six major dailying regions. The technique was applied using 12 independent variables believed by a panel of experienced research and extension personnel to exert the most influence on milk production. The regression equations were all significant (p < 0.001) with the percentage coefficients of determination ranging from 62 to 76% for equations developed using' total farm milk: production as the dependent variable. Three of the variables affecting total farm milk: production were found to be common to all six regions. These were; the amount of supplementary energy fed, the area set aside to irrigate winter feed and the size of the area used for dailying. Higher production farms appeared to be more efficient in that they consistently produced milk production levels higher than those estimated from the regression equation for their region. Other methods of analysis including robust regression and non linear regression techniques were unsuccessful in overcoming this problem and allowing development of a model appropriate for farms at all levels of production.

• Korean Journal of Ecology and Environment
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• v.44 no.4
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• pp.337-346
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• 2011

We investigated nutrient loading and trophic states in a coastal estuarine system in the Asan estuary by assessing phytoplankton biomass and using the trophic index (TRIX). The monthly and yearly nutrient loading (TN, TP) from freshwater discharge from the Asan and Sapgyo reservoirs into the estuary were estimated and analyzed with related factors. Monitoring data (physio-chemical and biological variables) collected at five estuary stations were used to assess trophic states. Descriptive statistics of total phytoplankton cells, chl a concentrations and primary productivity were also used to assess seasonal trophic status. N loading from freshwater ranged $1.0{\sim}1.3{\times}10^4$ ton yearly. The yearly P loading ranged between 350 and 400 ton during 2004~2006, increasing to 570 ton in 2007. Regression results suggest that DIN and DSi were correlated with freshwater discharge at the upper region. Based on phytoplankton biomass and total cell abundance, the trophic state of the estuary was found to be eutrophic during spring due to phytoplankton bloom. Primary productivity level was remarkably high, especially in summer coinciding with high nutrient loading. Pheopigments increased during warm seasons, i.e. summer and fall. Trophic index results indicate that the trophic state varied between mesotrophic and eutrophic in the estuary water body, especially in the upper region. The results suggest that phytoplankton production was regulated by nutrient loading from freshwater whereas biomass was affected by other properties than nutrient loading in the Asan Estuary ecosystem.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.203-203
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• 2023

총일차생산량(GPP, Gross Primary Productivity)은 생태계의 유기물 생산량을 나타내는 지표로써 생태계 생산성과 안정성을 파악할 수 있는 중요한 지표로 알려져 있다. GPP를 산출하는 대표적인 방법에는 다중 센서를 탑재한 원격 탐사 자료를 활용하는 방법과 플럭스타워를 통해 관측한 에디공분산을 분석하는 방법이 있다. 본 연구에서는 Landsat과 MODIS와 같이 시공간 해상도가 다른 원격 탐사 자료들을 기반으로 초고해상도 GPP 자료를 산출하기 위한 공간자료 융합 연구를 수행하였다. 이를 위해 GAN(Generative Adversarial Networks)과 같은 머신러닝 알고리즘을 활용하였으며 최종적으로 산정된 GPP 정보는 설마천과 청미천 등에 설치된 플럭스타워로부터 획득한 자료와의 비교·검증을 통해 평가되었다. 본 연구의 성과는 향후 증발산 자료, 생태계 호흡량 자료 등과의 조합을 통해 얻을 수 있는 물이용효율(WUE, Water Use Efficiency), 탄소이용효율(CUE, Carbon Uptake Efficiency)과 같은 지표 산정 시 적극 활용될 수 있을 것으로 기대된다.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.83-93
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• 2016

For the continuous stable production of oyster, estimation of food availability (F) was carried out in Goseong Bay, south of coast Korea. Primary productivity ranged from 0.07 to $0.44gC/m^2/day$ (average $0.25gC/m^2/day$), lowest in July and highest in January. The distribution of primary productivity at Goseong Bay showed the pattern of "high in the south and low in the north." Food availability (F) was $F{\leq}0$, indicating insufficient food supply, from August to November and F > 0 from January to April. Continuous insufficient food supply was observed at 18 oyster farms in the southern part of the bay and 4 in its northern part. Mortality at the oyster farms was 56% on the average, and around 58% of death occurred during November when food supply was insufficient. The optimal population of cultured oyster per unit flow area was calculated to be $110-115indiv./m^2$ (198-201 indiv./string). When the sea area was divided into 3 regions (A, B, C) according to carrying capacity, the carrying capacity of (A) regions was $52-53indiv./m^2$ (93-95 indiv./string), (B) regions was $142-144indiv./m^2$ (255-259 indiv./string), and (C) regions was $198-202indiv./m^2$ (356-363 indiv./string). In particular, (A) regions showed extremely low productivity. For continuous stable oyster farming at Goseong Bay, it is necessary to control point and non-point source pollution through continuous environmental monitoring and to adjust harvest according to the base carrying capacity during the season of high water temperature.

• The Korean Journal of Ecology
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• v.14 no.1
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• pp.63-73
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• 1991

Nakdong estuary provides the largest wintering grounds for migrating waterfowls in Korea, and was designated Natural Monument No. 179 in 1966. Nakdong barrage and related construction-projects finished in 1987 to increase freshwater-supply to nearby Pusan metropolitan area and to reclaim the vast intertidal areas for land development. Changes on distribution, primary productivity, and standing crop of Schoenopluctus triqueter, the dominant species in this intertidal flats, were investigated after the construciton, during the 1988-1990, and were compared to those before the construction. Total standing crop. tuber biomass and net primary productivity of S. triqueter increased in 1988 and 1989, but decreased slightly in 1990. Increase of tuber biomass means an increase in available food, thus the carrying capacity, for swans wintering in this area. Habitat environment of this estuary should be protected and managed as a wintering ground for migrating waterfowls, inspite of the construction of the barrage.