• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.4
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• pp.397-404
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• 2012

Jeju where concentrates on agriculture and tourism, conversion of outdoor culture into cultivation under structure happens actively for the purpose of increasing profit so continuous examination on house cultivation area is very important for this region. This paper is to suggest the effective image classification method using high resolution satellite image to detect the greenhouse. We carried out classification of greenhouse using the supervised classification and rule-based classification method about Formosat-2 images. Connecting result of two classification try to find accuracy improvement for greenhouse detection. Results about each classification method were calculated the accuracy by comparing with the result of visual detection. As a result, mahalanobis distance among the supervised methods was resulted in the highest detection. Also, it could be checked that detection accuracy was improved by tying with result of supervised method and result of rule-based classification. Therefore, it was expected that effective detection of greenhouse would be feasible if henceforward further study is performed in the process of connecting supervised classification and rule-based classification.

• Korean Journal of Medicinal Crop Science
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• v.25 no.1
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• pp.1-9
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• 2017

Background: Some plants have harmful effects on fungi and bacteria as well as other plants. Incorporating such plant into soil as green manure is effective in reducing population densities of soil pathogens. Methods and Results: Twenty-three species of green manure crops were cultivated after the harvest of 6-year-old ginseng and then incorporated into the soil at the flowering stage. The following year, the root rot ratio of 2-year-old ginseng and soil chemical properties were investigated. In the absence of green manure addition, the $NO_3$ content, electric conductivity (EC), and K content decreased by 95%, 79% and 65%, respectively. In the presence of green manure addition, $P_2O_5$ and $NO_3$ contents reduced by 41% and 25%, respectively. The "survived root ratio" of 2-year-old ginseng significantly increased by 56.2%, 47.5%, and 47.3%, in the Sorghum sudanense, Ricinus communis and Helianthus tuberosus treatment, respectively. In addition, there was a significant increase in the "survived root ratio" in the Secale cereale, Chrysanthemum morifolium, Atractylodes macrocephala, and Smallanthus sonchifolius treatments. The "survived root ratio" of ginseng showed a significant positive correlation with the soil pH and a negative correlation with the $NO_3$ contents, and EC. Conclusions: Cultivation of plant form the Chrysanthemum family as green manure, using mainly the rhizomes was effective for the control of root rot disease of ginseng.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.173-177
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• 1989

Cell density was gradually decreased as the dilution rate was increased under chemostat cultivation of HeLa cells. Maxium cell density was maintained at the dilution rate of 0.020 (1/h) which was far less than the wash-out rate of 0.050 (1/h), Maxium cell productivity of 2 (mL of cells/L/h)was obtained at the dilution rate of 0.030 (1/h) by showing the culture also required maintenance period at low dilution rates, whose result meant the deviation of continuous culture theroy. Methods of indirectly measuring cell density have been introduced to represent mammalian cell growth, which are packed cell volume and oxygen uptake rate, and these values showed good linear relationship with actual cell density by having correlation factor of 0.90. Theoretical maximum oxygen yield, $Y_{O2}^{max}$ and maintenance oxygen consumption rate, m$_{O2}$, were estimated as 4.1$\times$10$^5$ (cells/mmole $O_2$) and 10.71$\times$10$^{-9}$ (mmole $O_2$/cells/h) by employing oxygen yield model.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.519-524
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• 1996

The kinetics of growing microalga, Spirulina platensis was investigated to treat swine wastes with optimum growth conditions. Temperature was varied from 15 to 40$\circ$C at three different light intensities, 6 W/m$^{2}$, 12 W/m$^{2}$ and 24 W/m$^{2}$. The specific growth rate was increased as temperature increased up to 30$\circ$C. The activation energy was estimated as 13.5 kcal/mol by an Arrhenius relationship. 0.24 (1/day) of specific growth rate was obtained from batch cultivation with 30% swine wastes, compared to 0.31 (1/day) from clean culture. It was found that Spirulina platensis was able to reduce 70-93% of PO$_{4}$$^{3-}$ -P, 67-93% of inorganic nitrogen, 80-90% of COD and 37-56% organic nitrogen by adding various concentrations of swine wastes for 12 days of batch cultivation. Rate constants for removing nitrates and phosphates in treating swine wastes were estimated as 0.17 (1/day) and 0.14 (1/day) in the first order reaction, respectively. 1.52 (g/L) of maximum cell density was maintained at 0.20 (1/day) of dilution rate in continuous culture, adding 20% swine wastes for 30 days. The chemical composition of the biomass obtained from the process showed 58.7% of protein, 11.0% of lipid and 15.6% of ash.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.162-168
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• 2009

The aim of this study is to investigate microbial sanitary condition of public baths in Seoul, Korea. A total of 28 water samples were collected from 14 different public baths and sudatoriums. The prevalence of fecal indicator microorganisms such as total coliform, fecal coliform, and Escherichia coli was characterized. In addition, bacteria in water was membrane filtered by 0.45um nitrocellulose membrane, and the filter was analyzed by both cultivation and PCR amplification of partial 16S rRNA gene. The levels of chlorine were measured for each of water samples. More than 40% of 14 collected water samples, the concentrations of total coliform bacteria exceeded the water quality for bath water guideline. There was no significant correlation between chlorine residue and the presence of total coliform. Various microorganisms including pathogenic microorganisms were identified from cultivation and subsequent analysis of 16s rRNA gene sequences. Our results suggest that appropriate hygiene practice and continuous monitoring is needed for reducing health risk associated with public bathhouses.

• Smart Structures and Systems
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• v.13 no.2
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• pp.281-303
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• 2014

In order to suppress the wind-induced vibrations of the Canton Tower, a pair of active mass driver (AMD) systems has been installed on the top of the main structure. The structural principal directions in which the bending modes of the structure are uncoupled are proposed and verified based on the orthogonal projection approach. For the vibration control design in the principal X direction, the simplified model of the structure is developed based on the finite element model and modified according to the field measurements under wind excitations. The AMD system driven by permanent magnet synchronous linear motors are adopted. The dynamical models of the AMD subsystems are determined according to the open-loop test results by using nonlinear least square fitting method. The continuous variable gain feedback (VGF) control strategy is adopted to make the AMD system adaptive to the variation in the intensity of wind excitations. Finally, the field tests of free vibration control are carried out. The field test results of AMD control show that the damping ratio of the first vibration mode increases up to 11 times of the original value without control.

• ALGAE
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• v.34 no.2
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• pp.177-185
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• 2019

Ecklonia cava is popular in Korea as a marine functional materials. E. cava is generally collected and used on the coast of Jeju Island. However, the continuous use of collected natural E. cava may be limited because difficult to secure throughout the year and may be exposed to environmental pollution. Jeju magma seawater (MSW) was known to be significant advantages such as safety, cleanness, stability, and functional improvement. Attempts have been reported on application of MSW to the culturing of macro- and microalgae and showed improved results. Thus, the objective of the present study was to explore the anti-melanogenesis activity of brown seaweed E. cava (E. cava cultured with MSW [MSWE]) extract cultured in tanks with MSW of Jeju Island to evaluate the possibility of cosmeceutical industrial application. MSWE extract showed the higher polyphenolic and dieckol contents than natural E. cava (NE) extract. Anti-melanogenesis activity of MSWE extract and NE extract are tested and compared using tyrosinase and dihydroxyphenylalanine (DOPA) oxidation inhibition assay. MSWE extracts evidenced more effective tyrosinase and DOPA oxidation inhibition activity than that of the NE extracts and the commercial whitening agent, arbutin. MSWE extracts also markedly inhibited melanin synthesis and decreased the expression of melanogenesis-related protein in ${\alpha}$-melanocyte stimulating hormone-stimulated B16F10 melanoma cells without cytotoxicity. These results suggest that MSW cultivation process would be more effective in releasing bioactive compounds with whitening effect from seaweed such as E. cava at an industrial scale.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1325-1334
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• 2022

Global warming has accelerated in recent decades due to the continuous consumption of petroleum-based fuels. Cyanobacteria-derived biofuels are a promising carbon-neutral alternative to fossil fuels that may help achieve a cleaner environment. Here, we propose an effective strategy based on the large-scale cultivation of a newly isolated cyanobacterial strain to produce phycobiliprotein and biodiesel, thus demonstrating the potential commercial applicability of the isolated microalgal strain. A native cyanobacterium was isolated from Goryeong, Korea, and identified as Pseudanabaena mucicola GO0704 through 16s RNA analysis. The potential exploitation of P. mucicola GO0704 was explored by analyzing several parameters for mixotrophic culture, and optimal growth was achieved through the addition of sodium acetate (1 g/l) to the BG-11 medium. Next, the cultures were scaled up to a stirred-tank bioreactor in mixotrophic conditions to maximize the productivity of biomass and metabolites. The biomass, phycobiliprotein, and fatty acids concentrations in sodium acetate-treated cells were enhanced, and the highest biodiesel productivity (8.1 mg/l/d) was achieved at 96 h. Finally, the properties of the fuel derived from P. mucicola GO0704 were estimated with converted biodiesels according to the composition of fatty acids. Most of the characteristics of the final product, except for the cloud point, were compliant with international biodiesel standards [ASTM 6761 (US) and EN 14214 (Europe)].

• Journal of People, Plants, and Environment
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• v.23 no.2
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• pp.159-170
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• 2020

The purpose of this study was to understand the current status of education and programs and to identify the items that urban residents need most for garden management. First of all, there were 45 sites (40.5%) with gardens operated by city and county local governments nationwide, and 41(91.1%) of them had dedicated staff (1.8 persons on average). The average area of gardens was 18,623 m², garden area per person was 20.27m², the average number of participants was 683, and the average period of use was 8.69 months. In addition to gardening activities, 14 (31.1%) out of 45 sites were operating small group meetings, with an average of 2.29 meetings and 67 participants. In the satisfaction survey after gardening activities, 88.9% of 18 sites were satisfied. According to the questionnaire about education and programs related to garden users, an average of four sessions were conducted per education. In terms of education, the contents were in the following order: basic education on garden cultivation (33.9%) > prior education on garden operation (28.9%) > pest control (14.0%) > eco-friendly management (11.6%) > pesticides and Positive List System (9.9%) > others (1.7%). Over 95% of the respondents were generally satisfied. Regarding the perception survey on which items are needed to develop garden management guidelines, the most necessary items were in the order of crop management (38.7%) > public garden etiquettes among users (27.9%) > pest control (14.4%) > weed management (13.5%) > activities using harvest (5.4%). The contents that are to be included in the guidelines were in the order of garden planning and crop selection (17.2%) > cultivation techniques and schedule (16.5%) > pest and soil management (15.7%) > introduction of garden crops and gardening models (12.7%) > garden etiquettes (10.7%). In establishing urban garden management plans by region, the results will have high utility value as the basic data for continuous garden operation by setting a direction that meets the regional characteristics as well as the needs of urban residents.

• Journal of Korean Society of Rural Planning
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• v.29 no.4
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• pp.35-53
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• 2023

This study attempts to identify the flow of key topics and issues of research trends related to environment-friendly agriculture conducted around the 2000s in South Korea and compare them with the environment-friendly agriculture promotion plan to seek the level of consistency and the direction of future development of environment-friendly agriculture. For the analysis of environment-friendly agriculture research trends and policy consistency, 'topic modeling', which is suitable for subject classification of large amounts of unstructured data, and 'text network analysis', which visualizes the relationship between keywords as a network and interprets its characteristics, were utilized. Overall, active discussions were held on 'technical discussions for the production and cultivation of environment-friendly agricultural products' and 'food safety & consumer awareness', and keywords such as production, cultivation, consumption, and safety were consistently linked to other keywords regardless of time. In addition, it was found that the issue of environment-friendly agriculture was partially consistent with the policy direction of the period. Considering the fact that the ongoing '5th Environment-Friendly Agriculture Promotion Phase' emphasizes the strengthening of rural environment management and aims to ensure the continuous quantitative and qualitative development of environment-friendly agriculture, active discussions and research on its environmental contributions and management methods are needed.