• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.215-222
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• 2017

The potential change of the cultivation area of main citrus cultivars, satsuma mandarin (Citrus unshiu Marc.) and 'Shiranuhi' mandarin hybrid [(Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata] were determined with base year (1981 to 2010) to 2090. The meteorological data provided by the Korea Meteorological Administration (KMA), and the digital agricultural climate map of 30m-solution based on the Representative Concentration Pathways (RCP) 8.5 was used for projection of potential cultivation area. As a result, the potential suitable region of satsuma mandarin included almost Jeju region during base year. At the 2030s, the potential suitable region of satsuma mandarin increased and the cultivable region also increased focused on the coast region of Jeonnam province. From the 2060s, the suitable area spread out to mountain area of Jeju, Jeonnam, Gyeongnam, and the coast region of Kangwon, and the cultivable region expanded to the area of Gyeongbuk, Chungnam, and Jeonbuk. In the case of 'Shiranuhi' mandarin hybrid, the suitable region included only the partial coast area of Jeju, and cultivable area covered Jeju region and the partial southern coast of Jeonnam during the standard period. At the 2030s, the suitable region of 'Shiranuhi' included the current cultivation area of satsuma mandarin, and the cultivable region moved to northward by the partial southern coast region. At the 2090s, the slightly increased suitable region covered all Jeju regions, Jeonnam, Gyeongnam, and the coast area of Kangwon, and the cultivable region proceeded northward focusing on the coastline. In conclusion, the prediction of the potential land for citrus cultivation based on the RCP 8.5 showed that the suitable region of satsuma mandarin decreased, whereas that of cultivation of 'Shiranuhi' increased. Moreover, it was forecasted that citrus cultivation area would extend to Kangwon region at the end of the $21^{st}$ century.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.344-349
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• 2014

BACKGROUND: Purpose of the study was to establish the extinction coefficients of chlorophyll a and b in N,N-dimethylformamide(DMF) and Dimethylsulfoxide(DMSO) solvents and to find out the conditions of optimal extraction temperature and time in citrus leaves. METHODS AND RESULTS: Chlorophyll a and b standards were dissolved in DMF and DMSO. Extinction coefficients of chlorophyll pigments were determined and their contents were quantified using spectrophotometer. Chlorophyllous pigments of citrus(Citrus unshiu Marc. cv. Okitsu wase) leaves were extracted at 25, 40, 60 and $80^{\circ}C$ for 4, 6, 8, 24 and 48 hours to determine the optimal extraction condition. CONCLUSION: The extinction coefficients of chlorophyll a(Chl a) and chlorophyll b(Chl b) of DMF extracts for high extinction wavelength were 663.8 and 647.2 nm. Similarly, the high extinction wavelength of DMSO extracts were 665.8 and 649.0 nm for chl a and b respectively. Chl a, Chl b and total chlorophyll content of DMF extracts were Chl a = $12.10A_{663.8}-2.74A_{647.2}$, Chl b = $21.94A_{647.2}-5.06A_{663.8}$ and total $Chl=19.193A_{647.2}+7.04A_{663.8}$. Similarly, Chl a, Chl b and total Chl of DMSO extracts were Chl a = $14.53A_{665.8}-5.40A_{649.0}$, Chl b = $26.98A_{649.0}-7.11A_{665.8}$ and total $Chl=21.58A_{649.0}+7.43A_{665.8}$. The chlorophyll extracts of DMF and DMSO were very stable in dark. High chlorophyll contents of citrus leaves were found at $80^{\circ}C$ extraction for 6 hours in DMF and at $80^{\circ}C$ extraction for 24 hours in DMSO. However, the chlorophyll content was decreased significantly after 8 hours in DMF extraction while it was remained up to 30 hours in DMSO extraction.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.325-332
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• 2000

To determine the distribution and recovery of fall-applied N in various parts of satsuma mandarins (Citrus unshiu Marc). $19.68g\;N\;tree^{-1}$ as urea containing 5 atom % $^{15}N$ and 58 kg$K_2O$ $ha^{-1}$ were broadcast-applied to 11 years old 'Miyagawa Wase' grown at a spacing of $2.7{\times}2.7m$ on 18 November 1998. Nitrogen, $P_2O_5$, and $K_2O$ were applied at 104, 308, and $62kg\;ha^{-1}$ on 22 March and N and $K_2O$ at 42 and $83kg\;ha^{-1}$ on 15 June 1999. Two trees were excavated on 15 June and 8 December 1999, respectively. In mid-June, whole tree contained $168.2g\;N\;tree^{-1}$ of which 11.9, 42.1, 29.7, and 16.3% were in fruits, leaves, stems, and roots, respectively. In early December, total tree N averaged $169.8g\;tree^{-1}$ and fruits accounted for 27.6%, leaves 36.4%, stems 22.8%, and roots 13.2% of total tree N. Regardless of harvest date, N derived from fertilizer was highest in newly developed tissues. In mid June, the tree recovered 18.5% ($3.63g\;tree^{-1}$) of fertilizer N. Fruits accounted for 21.1%, leaves for 50.4%, stems for 21.5%, and roots for 7.9% of fertilizer-derived N in the tree, respectively. In early December, the tree recovered 17.0% of fertilizer N. Fruits contained 39.6%, leaves 40.5%, stems 14.5%, and roots 5.3% of fertilizer-derived N in the tree respectively. Comparing with total tree N, a higher proportion of fertilizer-derived N was allocated to metabolically active tissues while a less proportion to old tissues regardless of harvest date.

• Journal of Science and Technology Studies
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• v.16 no.2
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• pp.1-31
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• 2016

This essay examines the recent proliferation of location-based services (LBS) within the context the expansion of the technologies of remote identification, monitoring, and tracking. Following the spatial turn in the social sciences, this essay aims to analyze LBS as a surveillance technology that can re-shape the spatial configuration of its users and their identity. The analytic focus of this essay is on LBS within the global information infrastructure, and it utilizes key LBS examples in the US and South Korea. First, as a way to discuss the technical possibilities of LBS for spatial coordination and surveillance, this essay investigates its technical architecture in terms of information flow. It then discusses the issue of privacy in LBS by analyzing some of its key legal and regulatory issues. The combination of the global information infrastructure with location-related technologies has enabled LBS companies to expand the scope of surveillance over the ever-increasing computer-mediated activities, prompting heated discussions over whether LBS is capturing "Every Moment in Your Life." This essay concludes with a discussion on how location technologies have provided a key platform for the rise of surveillance capitalism through the creation of what Marc $Aug{\acute{e}}$ called a "non-place," a place where the identified self is constituted by LBS.