• Computers and Concrete
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• v.33 no.5
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• pp.559-572
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• 2024

Problems of under-sized dams (small dams with large basin area) could get worse under the global warming condition. This study evaluates the possible change of these problems with the Namgang Dam, an under-sized dam in Korea. For this purpose, first, this study simulates the dam inflow data using a rainfall-runoff model, which are then used as input for the reservoir operation. As a result, daily dam storage, dam release, and dam water supply are derived and compared for both past observed period (1973~2022) and future simulated period (2006~2099) based on the global warming scenarios. Summarizing the results are as follows. First, the inflow rate in the future is expected to be increased significantly. The maximum inflow could be twice of that observed in the past. As a result, it is also expected that the frequency of the water level reaching the high level is increasing. Also, the amount and frequency of dam release are to be increased in the future period. More seriously, this increase is expected to be concentrated on rather extreme cases with large dam release volume. Simply, the condition for flood protection in the downstream of the Namgang Dam is becoming worse and worse. Ironically, the severity of water shortage problem is also expected to become much worse. As the most extreme case, the frequency of no water supply was zero in the observed period, but in the future period, it becomes once every five years. Both the maximum consecutive shortage days and the total shortage volume are expected to become more than twice in the future period. To prevent or mitigate this coming problem of an under-sized dam, the only countermeasure at this moment seems to be its redevelopment. Simply a bigger dam with larger dam reservoir can handle this adverse effect more easily.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.350-356
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• 2020

Purpose: This study is a non-equilibrium control-like experimental study that attempts to develop a nursing intervention plan and to present basic data by grasping the effect of the heating therapy nursing intervention program on patients entering the recovery room after surgery. Method: The subjects of the study were 31 in an experimental group and 31 in a control group who applied one heating therapy program located in D city. The warming therapy was conducted in a recovery room in the range of 38 to 43℃ through a heater. The general characteristics of the subjects were determined by real number and percentage, and a homogeneity test between the experimental group and the control group was determined by 𝑥²-test and independent t-test. The difference in body temperature, pain, and tremor over time between the two groups was determined by repeated measure ANOVA. Results: First, the results of repeated measurements immediately after surgery showed significant differences in body temperature, pain, and tremor between the two groups. Second, temperature comfort showed a significant difference. Conclusion: The results confirmed that there was a positive effect on the patient in the intervention of warming therapy after surgery.

• KIEAE Journal
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• v.15 no.1
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• pp.147-154
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• 2015

Environmental impact assessment techniques have been developed as a result of the worldwide efforts to reduce the environmental impact of global warming. By using the quantification method in the construction industry, it is now possible to manage the greenhouse gas is to systematically evaluate the impact on the environment over the entire construction process. In particular, the proportion of greenhouse gas emissions at the production stage of construction material occupied is high, and efforts are needed in the construction field. In this study, intended for concrete products for the construction materials, by using the LCA evaluation method, we compared the results of environmental impact assessment and carbon emissions of developing products that have been applied low-carbon technologies compared to existing products. As a result, by introducing a raw material of industrial waste, showed carbon reduction. Through a comparison of the carbon emission reduction effect of low-carbon technologies, it is intended to provide academic data for the evaluation of greenhouse gases in the construction sector and the development of low-carbon technologies of the future.

• Journal of Environmental Policy
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• v.1 no.1
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• pp.1-24
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• 2002

Due to the recent increase in greenhouse gases in atmosphere, world climate is rapidly changing and in turn, the earth ecosystem responds upon the climate changes. Comparing the ecosystem in the past, the present shapes of ecosystem is the result of the serious modification. Fishery resources in marine ecosystem, which usually occupy the upper trophic level, are also inevitable from such changes, because they always react to the natural environmental conditions. The northwestern Pacific is the most productive ocean in the world producing about 30% of world catch. From time to time, however, it has been notified that abundance, distribution and species composition of major fish species were altered by climate events. Furthermore, primary productivity of the ocean is not stable under the changing environments, so that carrying capacity of the ocean varies from one climate regime to another. Major climate events such as global warming, atmospheric circulation pattern, climate regime shift in the North Pacific, and El Nino event in the Pacific tropical waters were introduced in relation to fisheries aspects. The current status and future projection of fishery production was investigated, especially in the North Pacific including Korean waters. This new paradigm, ecosystem response to environmental variability, has become the main theme in marine ecology and fishery science, and the GLOBEC-type researches might provide a solution far cause-effect mechanism as well as prediction capability. Ecosystem management principles for multi-species should be adopted for better understanding and management of ecosystem.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.1
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• pp.56-62
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• 2015

The potential impact of water temperature on sea level and air temperature rise in response to recent global warming has been noticed. To predict the effect of temperature change on river water quality and aquatic environment, it is necessary to understand and predict the change of water temperature. Air-water temperature relationship was analyzed using air temperature data at Buan and water temperature data of Shinsi, Garyeok, Mangyeong and Dongjin. Maximum and minimum water temperature was predicted by neural network and the results show a very high correlation between measured and predicted water temperature.

• Environmental Engineering Research
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• v.21 no.3
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• pp.284-290
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• 2016

Life cycle assessment (LCA) methodology can be used to assess impacts on the environment that might be generated during treatment of wastewater and sludge treatment. In this work, LCA methodology was suggested to evaluate monthly environmental impact of wastewater treatment plants (WWTPs). Two field scale WWTPs, A2/O process and conventional activated sludge process (CAS), were selected as target plants and the operational data were collected from those plants. As the function units, the unit volume of treated wastewater of $1m^3$ and 1 kg T-N eq. removed were selected. The environmental effect of target WWTPs operation were assessed as impact categories such as global warming potential, eutrophication potential, and so on. From monthly profiles of each index, it was shown that the environmental impact of WWTPs has seasonal patterns influenced by the influent flow rate variation causing higher impacts in winter than summer. This is due to the fact that there were no significant increase in the electricity consumption and chemical usage during the summer while the treated volume of wastewater was increased.

• 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.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.2
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• pp.197-206
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• 2013

Recently, climate change causes climatic anomaly such as global warming, the typhoon and severe rain storm etc. and it brings damage frequently. Climate change and global warming are prevalent all over the world in this century and many researchers including hydrologists have studied on the climate change. In this study, Seonakdong river watershed in the Nakdong river basin was selected as a study area. Real-time monitoring system was used to draw the rating curves, which has 0.78 to 0.96 of $R^2$. To predict runoff change in Seonakdong river watershed caused by climate change, the change in hydrologic runoff were predicted using the watershed model, SWAT. As a result, the runoff from the Seonakdong river watershed was increased by up to 45 % in summer. Because of the non-point sources from the farmland and the urban area, the water quality will be affected by the climate change. In this study, the operating plan of the water gates in Seonakdong river will be suggested by considering the characteristics of the watershed runoff due to the climate change. The optimal watergate opening plan will solve the water pollution problems in the reservoir-like river.

• Journal of Climate Change Research
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• v.8 no.1
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• pp.1-10
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• 2017

Over the past centuries, industrialization in developed and developing countries has had a negative impact on global warming, releasing $CO_2$ emissions into the Earth's atmosphere. In recent years, the transportation sector, which emits one-third of total $CO_2$ emissions in the United States, has adapted by implementing a climate change action plan to reduce $CO_2$ emissions. Having an environmental policy might be an essential factor in mitigating the man-made global warming threats to protect public health and the coexistent needs of current and future generations; however, to my best knowledge, no research has been conducted in such a context with appropriate statistical validation process to evaluate the effects of climate change policy on $CO_2$ emission reduction in recent years in the U.S. transportation. The empirical findings using an entity fixed-effects model with valid statistical tests show the positive effects of climate change policy on $CO_2$ emission reduction in a state. With all the 49 states joining the climate change action plans, the U.S. transportation sector is expected to reduce its $CO_2$ emissions by 20.2 MMT per year, and for the next 10 years, the cumulated $CO_2$ emission reduction is projected to reach 202.3 MMT, which is almost equivalent to the $CO_2$ emissions from the transportation sector produced in 2012 by California, the largest $CO_2$ emission state in the nation.