• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.93-100
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• 2002

This study was carried out not only to develop CFD model for numerically simulating fog cooling system but also to verify the validity of the developed model by data measured in fag cooling greenhouse. In addition the developed model was applied to investigate the effects of spraying water temperature, spraying water amount, spraying interval and evaporation percentage on the performance of the fog cooling system. According to the simulation results, the temperature differences between the measured and predicted temperatures at each measurement point were $0.1~1.4^{\circ}C$ in case of no shading and $0.2~2.3^{\circ}C$ in close of shading. The humidity differences were 0.3~6.0% and 0.7~10.6%, respectively in the cases of no shading and shading. Because the predicted data showed a good agreement with the measured ones, the developed model is supposed to be able to predict the cooling effect of the fog cooling system. The performance of fog cooling system was greatly influenced by spraying water amount, spraying interval and evaporation percentage, but it was not influenced by spraying water temperature.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.57-64
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• 1996

To use effectively the solar energy in greenhouse heating, a high performance solar collector should be developed. And then the size of the solar collector and thermal storage tank should be determined through the calculation of heating load. The solar collector must be set in the optimum tilt angle and direction to take daily solar radiation maximally, and the flow rate of heat transfer fluid through the solar collector should be kept in the optimum range. In this research, the performance tests of a capillary tube solar collector were performed to determine the optimum water flow rate and the results summarized as follows. 1. The regressive equations for efficiency estimations of the capillary tube solar collector in the open loop were modeled in the water flow rate of 700-l,000 $\ell$/hr. 2. The optimum water flow rate of the solar collector was estimated by the second order polynomial regression and the maximum efficiency was 80% at the water flow rate of 850 $\ell$/hr. 3. The solar thermal storage system consisted of a capillary tube solar collector and a water storage tank was tested at the water flow rate of 850 $\ell$/hr in the closed loop, and obtained the solar thermal storage efficiency of 55.2%. 4. As the capillary tube solar collector engaged in this experiment was made of non-corrosive polyolefin tubes, its weight was as light as 1/30 of the flat plate solar collector made of copper tubes. Therefore it was considered to be suitable for the greenhouse heating system.

• Journal of Bio-Environment Control
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• v.13 no.3
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• pp.149-155
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• 2004

On this study, a multipurpose operating system was developed to adjust a configuration of a moving path which have no connection with a form of greenhouse. To being performance the multipurpose working system, we have experienced growth quality on the plants in greenhouse. Some of the results are as follows. While watering by the hand spray. the condition of plant was generally no good. It was shown that plant height and leaf area were all high without wind during watering by the automatic spray. The effect to retrain a plant growth was high as a ventilation was strong. The diameter of a plant stem was small without ventilation condition during watering 3 times by automatic spray. The number of leaf was relatively large during 3 times by automatic spray compared to 2 times by automatic spray or hand spray. Growth of plant was fast as the times of spray were large.

• Korean Journal of Rural Living Science
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• v.8 no.2
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• pp.111-117
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• 1997

In this study we tried to give a decision on propriety of working conditions, to present ideas on reducing work loads. and to grope for efficiency of agricultural works. For this we examined the actual conditions of working environment, farmer's clothes, working posture, working methods, working time, resting state, fatigue recovery methods during cultivating lettuce in the winter greenhouse. And Ive improved harmful factors that affect farmer's health by considering results of previous study and farmer's subjective sensation. And we measured, compared, and analyzed the farmer's work loads before and after improvement. The results of this study are as follows ; 1. According to examine the actual conditions of cultivating lettuce in the winter greenhouse, farmers have experienced physical and mental chronic fatigue on the basis of the hot and humid crops-centered working environment, the rough ground condition, inconsistent arrangement of working stand and sorter, heavy-weared habits. and unsuitable working posture. 2. When we improved harmful factors that affect farmer's health, conformed the positive effects on important work efficiency index such as heart rate, electromyovolume, body temperature, and microclimate inside clothing and work loads were decreased by improving the hot and humid working environment, eliminating the hillock and obstacles of working path. deliver way, arranging the working stand and sorter consistantly, decreasing the clothing weight, improving the working postures and methods as using assistant appliances, alloting the working time and sequence effectively and presenting the light gymnastic exercises and rest for fatigue restoration.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.4
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• pp.14-21
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• 2015

Korean government plans to establish large-scale horticulture facility complexes using reclaimed land in order to improve the national competitiveness of agriculture at the government level. One of the most significant problems arising from the establishment of those large-scale horticulture facilities is that these facilities still largely depend on a fossil fuel and they require 24 h a day heating during the winter season in order to provide the necessary breeding conditions for greenhouse crops. These facilities show large energy consumption due to the use of coverings with large heat transmission coefficients such as vinyl and glass during heating in the winter season. This study investigated the applicability of waste heat from power plant for large-scale horticulture facilities by evaluating the waste heat water temperature, heat loss and energy saving performance as a function of distance between power plant and greenhouse. As a result, utilizing power plant waste heat can reduce the energy consumption by around 85% compared to the conventional gas boiler, regardless of the distance between power plant and greenhouse.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.229-234
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• 2010

Recently, nations around the world are putting various efforts in many aspects to decrease greenhouse gases and international cooperation is urgently required. As part of these efforts, the shipping industry is working towords establishing "green parts" that reduce the carbon content of the greenhouse gases emitted in ports and can also decrease the operating costs. This study has tried to look for how to supply shore power instead of suppling ship's own generated power as a basic researches for reduction of carbon emissions and construction of "green parts" system. And in this paper, the training ship 'SAENURI' of Mokpo Maritime University under actual operation was selected to investigate for environmental and expense effects. The results of this study showed that $CO_2$ emissions Mere reduced 34% and operating costs Mere reduced approximately 31% in case of using the shore paper.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.253-258
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• 2001

Biological control of thrips with Orius strigicollis Poppius was evaluated in a hot pepper greenhouse. To study the biological control strategy of thrips on hot pepper grown in greenhouse, three plots were established: natural enemy removed plot(CNT), pesticide treated plot(PAT) and O. strigicollis released plot with no pesticide application (NRT). The nymphs of O. strigicollis were found on the leaves of lower stratum in CNT and NRT at 13 days after the first release. The density of thrips was suddenly dropped and maintained at low level since 15 day after transplanting in NRT. The densities of thrips on hot pepper flowers was also maintained at much less level in NRT than in CNT. The thrips and O. strigicollis, which were aggregated in flowers, may have resulted in improved predator searching. Average damage indices of CNT, PAT and NRT were 0.31, 0.05 and 0.08 and the percentage of damaged fruit were 80.0, 17.1 and 24.8% respectively. The damage index and percentage of damaged fruit of NRT was slightly higher than PAT, but very lower than CNT. The introduction of the adults of O. strigicollis, which was the biological control agent for the control of thrips, was effective on hot pepper.

• The Korean Journal of Mycology
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• v.44 no.3
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• pp.127-131
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• 2016

Unusual mushrooms were observed in strawberry and sweet pepper greenhouses in the Hwasun area of Korea in September 2015. The mushrooms usually grew on beds in the greenhouses, frequently along with vegetables. The identity of the mushrooms in the greenhouses and effects of the mushrooms on the growth and quality of vegetables were investigated. Mushroom specimens collected were identified based on their morphological and molecular characteristics. The mushroom specimens collected from the strawberry greenhouse were identified as Leucocoprinus birnbaumii and L. ianthinus, and those from the sweet pepper greenhouse as Gymnopilus lepidotus. These were the first observations of L. ianthinus and G. lepidotus in Korea. The results revealed that the mushrooms originated from coco peat media used for the beds in the greenhouses. The mushrooms did not affect the growth and quality of the two vegetables.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.330-335
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• 2008

This experiment was carried out to investigate the effects of insecticide control system in eggplant greenhouse. In all treatments, the average densities of Frankliniella occidentalis and Tetranychus urticae were $0.3{\sim}1.8$ and 0.0 per leaf at 28 days after treatment, respectively. These results indicate the alternate application of Abamectin EC and Spinosad GW can be useful in control for F. occidentalis and T. urticae in eggplant greenhouse. The density suppression effect against Liriomyza trifolii and Trialeurodes vaporariorum was maintained for 28 days after treatment, but control effect was low at 28 days after treatment.

• International Journal of Highway Engineering
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• v.18 no.1
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• pp.119-129
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• 2016

PURPOSES : The purpose of this study is to develop a methodology for estimating additional carbon emissions due to freeway incidents. METHODS : As our country grows, our highway policy has mainly neglected the environmental and social sectors. However, with the formation of a national green growth keynote and an increase in the number of people interested in environmental and social issues, problems related to social issues, such as traffic accidents and congestion, and environmental issues, such as the impact of air pollution caused by exhaust gases that are emitted from highway vehicles, are beginning to be discussed. Accordingly, studies have been conducted on a variety of environmental aspects in the field of road transport, and for the quantitative calculation of greenhouse gas emissions, using various methods. However, in order to observe the effects of carbon emissions, microscopic simulations must use many difficult variables such as cost, analysis time, and ease of analysis process. In this study, additional greenhouse gas emissions that occur because of highway traffic accidents were classified by type (incident handling time, number of lanes blocked, freeway level of service), and the annual additional emissions based on incidents were calculated. According to the results, congestion length and emissions tend to increase with an increase in incident clearance time, number of occupied lanes, and worsening level of service. Using this data, we analyzed accident data on the Gyeong-bu Expressway (Yang-Jae IC - Osan IC) for a year. RESULTS : Additional greenhouse gas emissions that occur because of highway traffic accidents were classified by type (incident handling time, number of lanes blocked, freeway level of service) and annual additional emissions caused by accidents were calculated. CONCLUSIONS : In this study, a methodology for estimating carbon emissions due to freeway incidents was developed that incorporates macroscopic flow models. The results of the study are organized in the form of a look-Up table that calculates carbon emissions rather easily.