• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.511-520
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• 2020

Owing to global warming, heat waves have become stronger in the summer, and research on improving the thermal environment of green spaces, such as urban parks, is being conducted. On the other hand, studies on improving the urban thermal environment, which is changing due to the greening pattern and the intensity of the wind, are still insufficient. This study analyzed the temperature of the green spaces on campus to understand the factors affecting the temperature changes. After investigating the covering condition and planting form of the site, factors, such as temperature, humidity, wind direction, wind speed, and illuminance, were measured. The most influential factors on the temperature distribution are evapotranspiration and wind - induced heat transfer. The other major factors affecting the temperature change were the type of cover, wind velocity/wind direction, type of planting, shade / solar irradiance. In the type of cover, the plant was classified as low temperature, and the asphalt pavement was classified as high temperature. In wind speed, instantaneous temperature was reduced by 1.2 ℃ in southern wind, 0.7 ℃ in the westerly wind, 0.4 ℃ in the north wind and 0.5 ℃ in the east wind when a wind of 3.5m/s or more was blown.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.601-610
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• 2020

Recently, damage caused by drought is becoming worse and worse due to the global climate change. To overcome these problems, movable-weir to control the water level has been installed instead of a fixed-weir made from concrete. On the other hand, it is difficult to operate an existing moveable-weir because of the high cost of facility management and manpower consumption. In addition, because most moveable-weirs are installed in power systems, the operating cost and the cost of connection for power systems increase when they are located in remote areas. Therefore, this paper proposes an optimal design algorithm and the evaluation algorithm of the SOC (state of charge) of a lithium-ion battery to replace an existing power supply with eco-friendly movable-power with a power supply system using PV modules and lithium-ion batteries. In addition, this study modeled a 50kW power supply system of a movable-weir using PSCAD/EMTDC S/W. The simulation results confirmed that the proposed algorithm has stable operation characteristics in an independent operation mode and interconnection operation mode and that there is the possibility of commercialization with a benefits evaluation of the eco-friendly power supply system of a movable-weir.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.3
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• pp.95-102
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• 2000

The northward shift of the cultivation region of winter barley has been considered because of consecutive warm winters from the middle of 1980's. There was 1.02$^{\circ}C$ rise in mean air temperature during winter barley cropping season from 1975 to 1998. During this period, the maximum air temperature affected the mean air temperature rise rather than the minimum air temperature. The amount of mean precipitation was 513.3 mm during winter barley cropping season from 1975 to 1998 and was least in 1992. Sunshine hours has increased little by little in the all regions except rural regions. The air temperature during winter barley cropping season from 1987 to 1999 in which the winter was warm was higher than the normal air temperature(1961~1990). On the other hand, the air temperature during winter barley cropping season from 1974 through 1986 was similar to the normal air temperature. The amount of mean precipitation during winter barley cropping season from 1987 through 1999 was similar to the normal precipitation except April. During this period, the amount of mean precipitation of April was lower by 26 mm than the normal year(1961~1990). Sunshine hours during winter barley cropping season from 1987 to 1999 decreased generally in comparison with a normal year. Considering the air temperature rise during wintering from 1987 to 1998, it might be possible to extend the cropping area of winter barley northward.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.461-468
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• 2014

Biochar is a carbon rich solid produced by the pyrolysis of biomass such as energy crops, forestry residues, and wood wastes. Biochar returned to soil is to mitigate climate change and the feedstock of wood wastes reduces fossil fuel consumption as well as disposal costs. This study was practiced to evaluate a biochar system by gasification in terms of global warming regarding the soil application of the produced biochar. Life cycle assessment methodology was used to analyze the environmental impacts of the system, and the functional unit was 1 tonne of wood wastes. The result shows that the biochar system by using wood wastes as feedstock produces 4.048E-01 $kgCO_2-eq$ from the pre-treatment process as chipping and drying, 4.579E-01 $kgCO_2-eq$ from the pyrolysis process, and 9.070E-02 $kgCO_2-eq$ from the spreading to agricultural land, therefore total 9.534E-01 $kgCO_2-eq$ are generated. About 252 kg of $CO_2$ is still stored in the produced biochar in soil after carbon offsetting of the system. Therefore, the net carbon of the system is -251 kg of $CO_2-eq$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.1009-1019
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• 2009

In this research, various characteristics of South Korea's design flood have been examined by deriving appropriate design flood, using data obtained from careful observation of actual floods occurring in selected main watersheds of the nation. 19 watersheds were selected for research in Korea. The various characteristics of annual rainfall were analyzed by using a moving average method. The frequency analysis was decided to be performed on the annual maximum flood of succeeding one year as a reference year. For the 19 watersheds, tests of basic statistics, independent, homogeneity, and outlier were calculated per period of annual maximum flood series. By performing a test using the LH-moment ratio diagram and the Kolmogorov-Smirnov (K-S) test, among applied distributions of Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) distribution was found to be adequate compared with other probability distributions. Parameters of GEV distribution were estimated by L, L1, L2, L3 and L4-moment method based on the change in the order of probability weighted moments. Design floods per watershed and the periods of annual maximum flood series were derived by GEV distribution. According to the result of the analysis performed by using variation rate used in this research, it has been concluded that the time for changing the design conditions to ensure the proper hydraulic structure that considers recent climate changes of the nation brought about by global warming should be around the year 2002.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.840-846
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• 2012

Global climate changes caused by $CO_2$ emissions are currently debated around the world; green sources of energy are being sought as alternatives to replace fossil fuels. The sustainable use of biogas for energy production does not contribute to $CO_2$ emission and has therefore a high potential to reduce them. Catalytic steam reforming of a model biogas ($CH_4:CO_2$ = 60%:40%) is investigated to produce $H_2$-rich synthesis gas. The biogas utilized 3D-IR matrix burner in which the surface combustion is applied. The ruthenium catalyst was used inside a reformer. Parametric screening studies were achieved as Steam/Carbon ratio, biogas component ratio, Space velocity and Reformer temperature. When the condition of Steam/Carbon ratio, $CH_4/CO_2$ ratio, Space velocity and Refomer temperature were 3.25, 60% : 40%, $14.7L/g{\cdot}hr$ and $550^{\circ}C$ respectively, the hydrogen concentration and methane conversion rate were showed maximum values. Under the condition mentioned above, $H_2$ yield, $H_2$/CO ratio, CO selectivity and energy efficiency were 0.65, 2.14, 0.59, 51.29%.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.4
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• pp.283-290
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• 2014

Environmental changes, especially global climate change, are creating new routes to reduce a shipping service distance in Arctic area. The Arctic routes are shorter than 60% of existing ways Panama or Suez canal). For this reason, ship owners prefer to navigate in Arctic area and a transportation of goods though the Arctic area is increasing. But the low temperature in Arctic condition changes the material properties. Especially, the material will be brittle and strength will increase. And an ultimate strength analysis of ship stiffened panels is changed depending on temperatures. In present study, the ultimate strength analysis of stiffened panels in double hull oil tankers is performed under various low temperatures with the material properties obtained by tensile coupon test. The analytical method as named ALPS/ULSAP was used for analysis method and 6 kinds of temperature (20, 0, -20, -40, -60 and $-80^{\circ}C$) were considered to investigate the effect of Arctic conditions.

• Hwankyungkyoyuk
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• v.24 no.4
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• pp.111-128
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• 2011

This study was aimed at developing a common curriculum for the department of environmental education from 5 colleges of education. The need and background of curriculum reform can be summarized as follow; first, it has been recognized that new national curriculum of 2009 and 2011 created need for training teachers equipped with more integrated competency. Second, global environmental problems such as climate change and energy crisis asked for more responsible choice and action from all citizens. Third, the extremely low hiring rate resulted in the consideration of new working fields for teacher students majoring in environmental education. Fourth, the expansion of new environmental education paradigms including education for sustainable development called for practicing reconstruction of both contends and methods. From a series of research processes including analysis of current curriculum, DACUM, opinion survey and interest groups review, several new approaches for developing new curriculum had been identified as follow; first, content areas of environmental education should be extended beyond environmental natural science. Second, new learning approaches such as project-based learning need to be emphasized for strengthening the identity of environment as a separate subject. Third, more selective majoring system need to be applied in connection with environment government officials, researchers, and social environmental educators. It was recommended that the application of new curriculum developed by the study would be evaluated and managed by teaching conditions surrounding each of the five university members joined this developing processes. However, it needs to be noted that there is not much time because we had experienced zero hiring rate for the last 4 years and environmental policy and education programs are moving rapidly toward sustainable development.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.141-153
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• 2016

The increase in frequency and scale of natural disasters is the typical negative examples of the global climate change and the change of the human living environment in cities. The damage caused by natural disasters in particular including human and physical damage is directly linked to the safety and properties of citizens. Besides, the damage may occur to SOC facilities directly or indirectly. The SOC facilities damaged by disasters cause infringement of citizens safety rights. Therefore, a plan to provide prompt and effective risk map information by linking a 3D disaster information display system, which handles the information of the damage that may occur to SOC facilities such as bridges, beams, and dams at the time of disasters, with an on-site assistance application is suggested in this study. The prompt provision of risk map information is defined as a dynamic expression technology in this study. Also, disaster information is processed and compressed with a module developed to be linked organically to a system that displays disaster information, a proliferation system that can use the information on site, and a DB system that constructs a relationship with the information. Based on the module, the effective disaster information compression plan will be prepared, and the prompt information transmission system will be secured in the future.

• Korean journal of applied entomology
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• v.55 no.3
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• pp.257-266
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• 2016

Subtropical insect pests expand their habitats by migration to temperate zones along with global climate change. A subtropical insect pest, Maruca vitrata, is infesting leguminous crops including azuka beans in Korea and gives significant economic damages. Its great genetic variation raised an issue of the origin of a Korean M. vitrata population. To understand the genetic character of the Korean population, its cytochrome oxidase subunit 1 (cox 1) gene was sequenced and phylogenetically analyzed with other regional populations. The world populations of M. vitrata were grouped into three clusters: Asia-African, American, and Oceanian. The Korean population was classified into Asia-African cluster. To characterize the insecticide susceptibility of the Korean population, seven different insecticides (4 neutoxic insecticides, 1 insect growth regulator, 2 biopesticides) were assessed. Young larvae of M. vitrata were relatively susceptible to all tested insecticides. However, old larvae were much less susceptible than young larvae. No test insecticides effectively (> 50%) killed the old larvae of M. vitrata within 7 days.