• Atmosphere
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• v.20 no.4
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• pp.519-530
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• 2010

In this paper we review current research on Atmospheric Brown Clouds (ABCs) with lightweight Unmanned Aerial Vehicles (UAVs) and miniaturized instruments. The UAV technology for in-situ measurements, including aerosol concentration, aerosol size distribution, aerosol absorption, cloud drop size distribution, solar radiation fluxes (visible and broadband), and spectral radiative fluxes, is a leading-edge technology for cost-effective atmospheric sounding, which can fill the gap between the ground measurement and satellite observation. The first experimental observation with UAVs in Korea, Cheju ABC Plume Monsoon Experiment (CAPMEX), conducted during summer 2008 revealed that the Beijing plumes exerted a strong positive influence on the net warming and fossil-fuel-dominated black-carbon plumes were approximately 100% more efficient warming agents than biomass-burning-dominated plumes. Long-term sustainable routine UAV measurements will eventually provide truly three-dimensional data of ABCs, which is necessary for the better understanding of their climate impacts and for the improvement of numerical models for air pollution, weather forecast and climate change.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.4
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• pp.332-340
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• 2002

In these days, environmental concerns have been increased throughout the industry and community worldwide. To prevent the ozone depletion, ozone depletion potential of a refrigerant must be zero. Simultaneously, a refrigerant with low GWP (global warming potential) is very demanding to induce green house effect. Chlorine-free HFC-l34a is a refrigerant widely used for automotive air-conditioning system because its destruction potential is ecologically zero. Although HFC-l34a has no ozone depletion potential, its global warming potential is so high that it is not considered as a perfect alternative refrigerant that is acceptable for long-term use. In this paper, experimental measurement has been carried out to analyze the performance characteristics of automotive air-conditioning system using HFC-152a, which has low GWP and zero ODP. Also mixed refrigerant that is composed of HFC-152a and $CF_3$ was applied to investigate an alternative possibility for the automotive airconditioning system. As a result of this study, we could draw following conclusions; With respect to the variation of the rotational speed of compressor, outside air temperature and flow rate, the heat amount of evaporator and compressor and performance coefficient was varied.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.3
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• pp.140-149
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• 2003

In these days, environmental concerns have been increased throughout the industry and community worldwide. To prevent the ozone depletion, ozone depletion potential of a refrigerant must be zero. Simultaneously, a refrigerant with low GWP (global warming potential) is very demanding to reduce green house effect. Chlorine-free HFC-l34a is a refrigerant widely used for automotive air-conditioning system because its destruction potential is ecologically zero. Although HFC-l34a has no ozone depletion potential, its global warming potential is so high that it is not considered as a perfect alternative refrigerant that is acceptable for long-term use. In this paper, experimental measurement has been carried out to analyze the performance characteristics of automotive air-conditioning system using HFC-152a, which has low GWP and zero ODP. Also mixed refrigerant that is composed of HFC-152a and $CF_3$ was applied to investigate an alternative possibility for the automotive air-conditioning system. As a result of this study, we could draw following conclusions; With respect to the variation of the rotational speed of compressor, outside air temperature and flow rate, the heat amount of evaporator and compressor and performance coefficient was varied.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4B
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• pp.421-428
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• 2008

For last decades, the rapid coastal erosion process spreading along Korean peninsular has become a nuisance especially for tourism and local economy. Global warming and sea-level rise demand persistently new coastal protection strategies against the conventional methods using armored structures. In a view of this, Kweon et al. (2007) has proposed a new type of horizontal steel plates for an ideal candidate as eco-friendly detached breakwater systems for global warming era. The breakwater is composed of piles and horizontal porous plates that was devised for the optimized blockage effects and wave energy dissipations. This system provides outstanding performances as wave barrier and added advantages such as a rapid installation, an easy relocation, a perfect water circulation for the stagnation of pollutions in sheltered regions. The present experimental study focuses on the performance evaluations of the proposed system in wind wave conditions as a wave dissipator and reflector. The reflection, transmission, and energy dissipation of the random waves has been discussed in detail based on a newly proposed relation between wave steepness and a plate width normalized by wave length that are major factors affecting the wave transmission.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.1
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• pp.24-30
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• 2011

Objective: The objectives of this study were to analyze efficacy of immature and mature mouse oocytes after vitrification and warming by applying various combinations of cryoprotectants (CPAs) and/or super-rapid cooling using slush nitrogen ($SN_2$). Methods: Four-week old ICR female mice were superovulated for GV- and MII-stage oocytes. Experimental groups were divided into two groups. Ethylene glycol (EG) only group: pre-equilibrated with 1.5 M EG for 2.5 minutes and then equilibrated with 5.5 M EG and 1.0 M sucrose for 20 seconds. EG+dimethylsulfoxide (DMSO) group: pre-equilibrated with 1.3 M EG+1.1 M DMSO for 2.5 minutes and equilibrated with 2.7 M EG+2.1 M DMSO+0.5 M sucrose for 20 seconds. The oocytes were loaded onto grids and plunged into $SN_2$or liquid nitrogen ($LN_2$). Stored oocytes were warmed by a five-step method, and then their survival, maturation, cleavage, and developmental rates were observed. Results: The EG only and EG+DMSO groups showed no significant difference in survival of immature oocytes vitrified after warming. However, maturation and cleavage rates after conventional insemination were greater in the EG only group than in the EG+DMSO group. In mature oocytes, survival, cleavage, and blastocyst formation rates after warming showed no significant difference when EG only or EG+DMSO was applied. Furthermore, cleavage and blastocyst formation rates of MII oocytes vitrified using $SN_2$ were increased in both the EG only and EG+DMSO groups. Conclusion: A combination of CPAs in oocyte cryopreservation could be formulated according to the oocyte stage. In addition, $SN_2$ may improve the efficiency of vitrification by reducing cryoinjury.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.267-267
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.280-280
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• 2017

In Korea, the average air temperature has been elevated twice faster than the average global warming. And the climate warming is characterized by the smaller rise of air temperature in summer and the greater rise of air temperature in spring and winter. Therefore, the number of frost-free days to determine the cultivation ability of crops has increased by more than 15 days in 10 years according to climate warming. This climate warming trend has extended and is projected to extend not only the sweet potato growing season but also the sweet potato early cultivating area to higher altitude and latitude region. This study was carried out to evaluate the possibility of sweet potato double cropping in the southern island area of Korea by assessing the growth and yield performance of sweet potato cultivated at extremely-early and -late time. We had performed at Yokji Island Yokji Island($E128^{\circ}$ 18' $N34^{\circ}$ 36'), a representative specified complex area of sweet potato cultivation in southern Korea. As the test varieties, the major cultivars of the this region, Shinyulmi and early hypertrophic cultivars, Dahomi were used. The prior cropping were planted with PE film mulching on March 30 and April 10, and harvested after 110 days. So the succeeding cropping were planted without PE film mulching on July 25 and August 5 according to the harvesting time of the prior sweet potato and harvested after 120 days. As a control, it was harvested on September 15, 120 days after planted on May 15. Each experimental plot had an area of 12 square meters consisting of 4 beds, and was planted one at a time at intervals of 25cm. We had investigated growth characteristics - main vine length, node number, branch number, total vine yield, and tuberous root characteristics - tuberous root number, average weight, starch value, and etc. After harvesting, we analyzed the economic effects by examining the postharvest quantity, the input labor, the management cost, and the income. The total yield of marketable products in prior and succeeding cropping was 46~70% higher than that of control. The average unit price of sweet potato was 36% higher than the conventional culture, and the gross income increased by 98%, but the operating cost increased by 83%, and the farm income increased by 103%. There are considerations such as the difficulty of enlargement of cultivation area due to lack of labor in limited space and the need for watering measures due to spring drought. However, if the area of application for sweet potatoes double system is increased by 10%, it can be used as a new cropping system.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.522-529
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• 2013

Climate change will affect the physiological traits and growth of forest trees. This study was conducted to investigate the effects of an experimental warming on growth and physiological characteristics of Pinus densiflora S. et Z. seedlings. One-year-old P. densiflora seedlings were planted in control and warmed plots in April 2010. The air temperature of warmed plots was increased by $3^{\circ}C$ using infrared lamps from November 2010. We measured shoot height, root collar diameter, above and below ground biomass, chlorophyll contents and leaf nitrogen concentration from March 2011 to March 2013. Seedling height and root collar diameter showed no significant difference between warmed and control plots except for root collar diameter measured in June 2012. Seedling leaf biomass was lower in the warmed ($23.94{\pm}2.10g$) than in the control ($26.08{\pm}1.72g$) plots in 2013. Shoot to root ratio (S/R ratio) was lower in the warmed ($1.09{\pm}0.07$) than in the control ($1.31{\pm}0.10$) plots in 2013. Leaf nitrogen concentrations and chlorophyll contents were not significantly different between warmed and control plots except for leaf nitrogen concentration in 2011. Leaf C/N ratio was increased in 2012 under the warming treatment. Low growth and S/R ratio in warmed plots might be related to the higher temperature and water stress. In the future, the below-ground carbon allocation of P. densiflora might be increased by global warming due to temperature and water stress.

• Journal of Korean Academy of Nursing
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• v.30 no.5
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• pp.1318-1332
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• 2000

The purpose of this study was to determine the effect of walk training on leg strength, flexibility, postural stability, balance and gait in home bound elderly women. Eighteen elderly women of the experimental group aged between 70 and 90 years image who have normal vision, hearing and Romberg test. They participated in the 12 week walk training. The subjects of the experimental group practiced walk training 3 times a week for during 12 weeks. During the 40 minute workout, the subjects practiced 5 minutes of warming-up exercises, 30 minutes of conditioning exercises and 10 minutes of a cool-down exercise. The intensity for the conditioning phase was determined by subject' heart rates, which ranged from 60% to 70% of age-adjusted maximum heart rates. The body composition, leg strength, flexibility, postural stability, balance and gait were measured prior to and after the experimental treatment. The body fat, lean body mass, leg strength (ankle dorsiflexor, plantarflexor, inversor and eversir, knee flexor, extensior), flexibility (range of motion of ankle dorsiflexion, plantarflexion, inversion and eversion), and postural stability of the experimental group were significantly greater than those of the control group. Duration of standing on the right foot and that of standing on the left foot of the experimental group was greater than that of the control group. Total balance scores of the experimental group were significantly higher than those of the control group. Among 13 items for balance, the scores of experimental group in balance with eyes closes, turning balance, sternal nudge, neck turning, one leg standing balance and back extension were higher than those of the control group. Total scores of gait of the experimental group were significantly higher than those of the control group following the walking training. Scores of experimental group in step height, step length and walk stance while walking among 9 items for gait were significantly higher than those of the control group. The results suggest that walk training can improve physical fitness for prevention in home bound elderly women.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.159-164
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• 2014

The objective of this study was to establish an open-field experimental warming treatment and precipitation manipulation system to simulate climate change impact for Pinus densiflora seedlings based on a climate change scenario in Korea. Two-year-old seedlings were planted in a nursery in April, 2013. The air temperature of warmed plots (W) was set to increase by $3.0^{\circ}C$ compared to control plots (C) using infrared lamps from May, 2013. The three precipitation manipulation consisted of precipitation decrease using transparent panel (-30%; $P^-$), precipitation increase using pump and drip-irrigation (+30%; $P^+$) and precipitation control (0%; $P^0$). Initially, the air temperature was $2.2^{\circ}C$ higher in warmed plots than in control plots and later air temperature was maintained close to the target temperature of $3.0^{\circ}C$. The average soil temperature was $3.1^{\circ}C$ higher in warmed plots than in control plots. Also the average soil moisture content after the precipitation manipulation increased by 13.9% in $P^+W$ and decreased by 10.0% in $P^-W$ compared to $P^0W$, and increased by 23.7% in $P^+C$ and decreased by 7.6% in $P^-C$ compared to $P^0C$. It was confirmed that the open-field experimental warming and precipitation manipulation system was properly designed and operating.