• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.57-65
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• 2000

Objective of research is obtain fundamental data of carbonized wood wastes for soil condition, de-ordorization, absorption of water, carrier for microbial activity, and purifying agent for water quality of river. The carbonization technique and the properties of carbonized wood wastes(wood-based materials) were analyzed. Proximate analysis showed the wood-based materials contains 0.37~2.27% ash, 70~74% volatile matter, and 17~20% fixed carbon. As carbonization temperature was increased, the charcoal yield was decreased. However, no difference in charcoal yield was found due to time increase. The specific gravity after the carbonization decreased about 30~40% comparing to green wood. The charcoal had 1.08~4.18% ash, 5.88~13.79% volatile matter, and 80.15~90.94% fixed carbon. The pH of plywood and particleboard(pH 9 at $400^{\circ}C$, pH 10 at $600^{\circ}C$ and $800^{\circ}C$) made charcoals was higher than that of fiberboard. The water-retention capacity was not affected by the carbonization temperature and time. The water-retention capacity within 24h was about 2~2.5 times of sample weight, and the Equilibrium moisture content(EMC) became 2~10% after 24h. EMC of charcoal from the thinned trees were 9.40~11.82%($20^{\circ}C$, RH 90%), 6.87~7.61%($20^{\circ}C$, RH 65%), and 1.69~2.81%($20^{\circ}C$, RH 25%). EMC of charcoal from the wood-based materials under $20^{\circ}C$, relative humidity(RH) 90% was similar to EMC of charcoal from the thinned trees(9~11 %). However, under $20^{\circ}C$, RH 25.65%, EMC of charcoal from the wood-based materials were higher(2~3%) than EMC of charcoal from the thinned trees. Every charcoal from the wood-based materials fulfilled the criteria in JWWA K 113-1947.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.56-71
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• 1980

To study the changes of vegetational composition of each plant successional stage of Pinus densiflora forest caused by pine gall midge damage, Thecodiplosis japonensis, located in Kyonggi-do area, the middle part of Korea, four districts, Anseong, Yongin, Gwangju, and Gapyeong, were selected according to the length of insect damage duration. The forest in the Anseong district was the noninfested one selected as the check. And forests in Yongin, Gwangju, and Gapyeong were the recent]y damaged, severely damaged, and damage prolonged ones in sequence. It was considered that this order could be in concord with the gradual transition of plant successional stage. In view of temperature, precipitation and soil factors, these four districts were sited within the same environment. Four survey plots were selected from each district and the distance between them was 3~4 km. Then again four subplots were set within a plot. Through needle accumulation after insect infestation, light intensity, soil moisture content, and the amount of soil organic matter were increased and these conditions could create a favorable environment enabling the new species invasion and their growth. These were naturally closely related with the increase in quantity of Pinus densiflora defoliation. After considerable time lapse, the quantities of above mentioned factors decreased with the development of the new substitute tree species. It was found that Quercus mongolica was an excellently substitute tree species come first in this studied area. Species diversity increased to a degree at the early stage of the duration of pine gall midge damage and decreased thereafter. As the same manner, similarity index value between plots in the same district decreased to a degree and increased thereafter. This was linked admittedly with the increase and decrease of tree species and evenness. Synthesizing above mentioned results, the process of plant succession studied quantitatively by changes of relative density and relative importance value, it can be concluded that Pinus densiflora forest gives way to Genus Quercus forest in which Genus Lespedeza and Genus Rhododendron species become as subdominance species after removal of the Pinus densiflora trees damaged by pine gall midge.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.248-252
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• 2012

To evaluate the possibility of water plant wastes in composting for agricultural recycling, Phragmites communis (PHRCO), Typha orientalis (TYHOR) and Zizania latifolia (ZIZLA) were used as a compost materials. In composting basin, cumulative oxygen consumptions of the compost used by water plant wastes were rapidly increased at the early stage and slightly decreased in around 15 days. Cumulative oxygen consumptions under different water plant wastes were higher in the order of TYHOR > ZIZLA > PHRCO. Temperature changes during composting process were rapidly increased at the early stage and then slowly decreased to $30{\sim}40^{\circ}C$. The maximum temperatures were higher in the order of ZIZLA ($72.2^{\circ}C$ at 11 days after starting composting) > TYHOR ($70.2^{\circ}C$ at 10 days after starting composting) > PHRCO ($66.5^{\circ}C$ at 7 days after starting composting). Oxygen consumptions at maximum temperature were higher in the order of TYHOR ($12,485mg\;O_2\;kg^{-1}$) > ZIZLA ($12,400mg\;O_2\;kg^{-1}$) > PHRCO ($9,340mg\;O_2\;kg^{-1}$). Organic matter contents, moisture contents and OM/N rates in the compost ranged 39.5~44.8%, 29.6~35.6% and 27.9~32.9, respectively. Considering that water plant waste can supply some of the nutrient requirements of crops and is a valuable fertilizer.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.34-39
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• 2005

There are various crop diseases in green houses that are caused by the cultural environments, especially high temperature and moisture. To solve the forementioned problems, farmers are overusing agricultural chemicals, causing other damages by the chemical residue. In this study, antagonistic bacteria as biological control agents were isolated to produce the environmentally-friendly crops for use in green houses. Eighteen species of antagonistic bacteria were totally isolated from the soil and plants in the Perilla fields, and AK-17 showed the highest activity among the isolates. According to the results of anti-fungal spectrum against several pathogens by AK-17, the antagonism effect of the isolates was remarkable against grey mold rot by Botrytis cinerea, sclerotinia rot by Sclerotnia sclerotiorum, and stem rot by Rhizoctonia solini. To evaluate the biological control effects of the isolates against the major diseases of Perilla, studies were carried out to evaluate the preventive and the curative effects of the diseases throughout the pot experiments. According to the forementioned experiments, the preventive and the curative effects by the isolates against sclerotinia rot were respectively showed as 55% and 92%. For the grey mold rot, those were 40% and 78%, respectively. As to the evaluation of the growth-promoting effect by AK-17, the length and the biomass of the tested plants were increased to 120% and to 164%, respectively. For the leaf numbers and area were respectively increased to 120% and 220%. Furthermore, AK-17 was identified as Burkhoderia sp. according to the results of physiological properties and genetic methods.

• Journal of Sericultural and Entomological Science
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• v.24 no.1
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• pp.19-24
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• 1982

This experiment was carried out to develope a new planting system from the economical point of view, using the various sizes of mulberry saplings ranged from 3mm to 7mm (3, 4, 5 and 7mm) in diameter of branches. They were planted densely (2,285 trees/10a) in vinyl film-and non-mulching system. The results are summarized as follows. 1. There are no differences in growth and yield of the planting year between 6mm and 7mm saplings. 2. The vinyl mulching affords an abundant growth of the saplings due to retaining of soil temperature and moisture. The dense planting with vinyl film mulching gave rise to 26% and 7% increase of leaf yield, using the saplings sized of 7mm and 5mm, respectively. 3. On the other hand, it was evident that the use of 6mm saplings in non-mulching and 5mm ones in mulching redused possibly the sapling cost. It was also noteworthy an additional profit took places in the yield increase, the cost reduction of saplings and weeding by using the 7mm and 5mm saplings in mulching system. It amounted to the increase of ￦33,800 and ￦24,520, respectively over the use of 7mm saplings in non-mulching system.

• Archives of design research
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• v.21
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• pp.99-106
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• 1997

There were the changes of shapes and color tones when the soil materials e.g. Blue-Porcelain, White-Porcelain, Bunchong, mixed A and B, mullite, Sanchong and Ongki - used by most domestic ceramic artists - were glazed at $ 950^{\circ}C,; 1200^{\circ}C,; 1250^{\circ}C,; 1280^{\circ}C,;1300^{\circ}C$ After the materials were dried out at 120t: in an electric oven, they were mixed with water, keeping the percentage of moisture content 25% and kneaded specimens which are hexahedron by $$ 250{\times}30{\times}8mm$$were produced and dried after calibrated at 200mm interval with a vernier caliper. After the materials were dried and glazed, they showed few shape-changes at $950^{\circ}C$ but began to changed at $1200^{\circ}C$,especially Bunchong and Ongki made rapid changes. In the case of color-change, White-Porcelain changed very little. The color of Blue-Porcelain, mixed A and B, Sanchong, Mullite changed to ]aune brilliant as temperature went up but Bunchong and Ongki changed to dark brown or dark chocolate under the same conditions. This study aims at suggestion of the basic data which minimize failure rates by recognizing the property of the materials on the basis of this study and regulating shape-change phenomena and sensitive changes of color when ceramic artists work.

• Journal of Korean Society of Forest Science
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• v.56 no.1
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• pp.51-65
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• 1982

The growth characteristics and appropriate fertilizer-managements in the rejuvenating bamboo grove were studied with Phyllostachys reticulata. The bamboo soil was the sandy loam with rich humus. In the fertilized plots, the N-fertilizer was significantly absorbed, and it was necessary to fertilize the K-fertilizer continuously. According to the development of rejuvenating after flowering, the temperature and relative illumination became lower. while the moisture became higher. The relationship between the diameter at eye height (D) and the culm length (H) of each bamboo can be expressed as follow; $H=2.5538D^{0.5031}$ The leaf area is the major factor for the production of the bamboo grove. Therefore in the rejuvenating grove, we should refrain form pruning or felling of not -flowering bamboo. The theoretical distribution of the internodal length was obtained by the distribution curve line of the internodal length derived from the regular distribution curve line. Relatively long and even internodal length was found in the fertilized plots 2 and 4. The relation between $D^2H$ and dry weight of culm or dry weight of the above ground part were given by linear regression in both relations respectively on the logarithmic coordinates, but the propertional relation was not established in these relations. The biomass of the above ground part obtained by the allometry method showed high values in the fertilized plots 2.5 and 6. The appropriate amounts of the three elements, N, P and K for the maximum dry matter were 24.19, 15.51, 8.63 kg/10a, respectively.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.667-677
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• 2020

Crop water stress can be detected based on soil moisture content, crop physiological characteristics and remote-sensing technology. The detection of crop water stress is an important issue for the accurate assessment of yield decline. The crop water stress index (CWSI) has been introduced based on the difference between leaf and air temperature. In this paper, drone-based thermal infrared image was used to map of crop water stress in water control plot (WCP) and water deficit plot (WDP) over spring chinese cabbage fields. The spatial distribution map of CWSI was in strong agreement with the abnormal growth response factors (plant height, plant diameter, and measured value by chlorophyll meter). From these results, CWSI can be used as a good method for evaluation of crop abnormal growth monitoring.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.163-171
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• 2017

Effects of different packaging methods for maintaining the shelf life and postharvest quality of iceberg lettuce (Lactuca sativa L.) were studied after harvesting in summer season. Lettuce heads were packaged in plastic crate with or without different films such as (A) Individual lettuce head sealed packaging with linear low density polyethylene (LLDPE) film; (B) Packaging lettuce head in plastic crate and wrapped with LLDPE film; (C): Individual lettuce head sealed packaging with perforated high density polyethylene (HDPE) film; (D) Packaging lettuce head in plastic crate and wrapped with perforated HDPE; and (E) Packaging lettuce head in plastic crate without any film (control), and stored at $2^{\circ}C$ for 35 days. Several quality parameters such as fresh weight loss, SPAD (soil & plant analyzer development) meter value, respiration rate, moisture content and appearance of lettuce were investigated. The lettuce wrapped with individually-sealed LLDPE film showed the lowest weight loss and the highest SPAD value rendering the best appearance index among the treataments throughout the three-week storage period at $2^{\circ}C$. Extending the freshness of iceberg lettuce during low temperature storage will definitely increase the salability potential in the domestic market even during summer season.

• Journal of the Korean association of regional geographers
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• v.18 no.4
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• pp.473-493
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• 2012

Malaria infection is sensitively influenced by regional meteorological conditions along with global climate change. Remote sensing techniques have become an important tool for extraction of climatic and environmental factors, including rainfall, temperature, surface water, soil moisture, and land use, which are directly linked to the habitat qualities of malaria mosquitoes. Improvement of sensor fidelity with higher spatial and spectral resolution, new multinational sensor development, and decreased data cost have nurtured diverse remote sensing applications in malaria research. In 1984, eradication of endemic malaria was declared in Korea, but reemergence of malaria was reported in mid-1990s. Considering constant changes in malaria cases since 2000, the epidemiological management of the disease needs careful monitoring. Geographically, northmost counties neighboring North Korea have been ranked high in the number of malaria cases. High infection rates in these areas drew special attention and led to a hypothesis that malaria dispersion in these border counties might be caused by north-origin, malaria-bearing adult mosquitoes. Habitat conditions of malaria mosquitoes are important parameters for prediction of the vector abundance. However, it should be realized that malaria infection and transmission is a complex mechanism, where non-environmental factors, including human behavior, demographic structure, landscape structure, and spatial relationships between human residence and the vector habitats, are also significant considerations in the framework of medical geography.