• KIEAE Journal
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• v.16 no.5
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• pp.47-55
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• 2016

Purpose: As the energy consumed by buildings increases, there is a growing need for studies and technology development to address this issue. One of the solutions to excessive energy use by buildings is the light-shelf, which is a natural lighting system enabling efficient reduction in light energy, and research in this area has been intensive. However, most of the studies about the light-shelf are limited to the light environment, and thus the application of their findings to an actual environment in the form of a design may be problematic. Therefore, the purpose of the present study is to provide fundamental data for light-shelf design by carrying out a light-shelf performance evaluation on the basis of the light environment and the heating and cooling environment. Method: In the present study, a testbed was established to conduct a light-shelf performance evaluation by measuring the electric power consumption of lighting and heating and cooling devices depending on the existence of a light-shelf and its angle. Result: The findings of the present study are as follows: 1) With respect to the uniformity of the indoor light environment amenity, the optimum angle of a light-shelf was found to be $30^{\circ}$ for the summer solstice and the winter solstice. 2) With respect to the reduction of electric power consumption by indoor lighting devices, the optimum light-shelf angle at the summer solstice is $30^{\circ}$, at which time electric power consumption may be reduced by 10.2% in comparison with when no light-shelf is applied. However, at the winter solstice, a light-shelf may increase the energy consumption for lighting in comparison with when no light-shelf is applied, and this should be taken into account in the design of a light-shelf. 3) In terms of reducing the electric power consumption of heating and cooling devices, the optimum angle of a light-shelf was found to be $30^{\circ}$ for the summer solstice, while a light-shelf is inappropriate for the winter solstice since a light-shelf creates shade and thus increases the heating energy consumption. 4) To summarize the findings above, the optimum angle of a light-shelf is $30^{\circ}$ for the summer solstice, but the installation of a light-shelf may in some circumstances increase the energy consumed by lighting devices as well as by heating and cooling devices. Therefore, more studies and technology development may need to be performed to solve the problem of increased energy consumption at the winter solstice.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.127-133
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• 1998

The atmospheric deposition flux was measured with dustfall from July of 1997 to July of 1998 at nine sampling sites located in Tae-an peninsula to examine the seasonal variations. The results showed that the average dry deposition was higher in spring than the other seasons. Thus, it is considered that yellow sand is one major source of the additional deposition flux in spring. There also appeared the higher measurement of deposition at the sites nearby road (like Hagampo, Bangali and Sinduri) in summer, and it is assumed that the heavy traffic caused by summer visitors was the main factor of that. For more accurate study, the qualitiative analysis should be taken on the deposited materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.230-236
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• 2009

In this paper, in order to utilize new and renewable energy a grid-connected parasol-type solar power generation system is presented. The proposed power system combining with commercial electric power system is designed to meet the need fur maximum power consumption and parasols for the people staying at beach during hot summer. Solar electric power can be charged in rechargeable batteries during day time and used to provide charged electric power to loads like lamps and fans during night time, A battery charge-discharge controller is required for the good performance of batteries to be charged. The presented battery controller is designed based on high performance microprocessor for precise charge-discharge operations. An alarm circuit to give notice of battery exchange time and other convenient functions are installed in the system. We implemented the proposed solar power generation system at East Sea beach during peak summer season to verify its productivity and performance by experiments.

• Journal of the Korean Geographical Society
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• v.28 no.3
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• pp.193-199
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• 1993

The interannual fluctuation, trends and perio-dicties in summer rainfall of South Korea were analyzed primarily by using Mann-Kendall rank method and Power Spectrum analysis for the period from 1920 to 1985. Their relations to Indian summer monsoon rainfall have also been examined. Increasing or decreasing rainfall tendencies are not found in South Korea. In Power Spectrum alalysis, 2.5 years periods are predominent at the 95 per cent confidence level in south Korea as a whole and Pusan. Also the period of 11.0 years is found in Seou. There are another prominent spectral peaks at 2.4, 3.1, 6.2 and 7.3 years period, which are significant at 90 per cent confidence level.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.11-18
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• 2003

This study was carried cut to get basic data of troubles in starting and supply of farm diesel engines in cold winter. The results of the study are summarized as follows: 1. As the result of farm survey. the proportions of farms which had starting problems or troubles in fuel supply in cold winter for the last 5 years were 38% for the farms with power-tillers and 32% for the farms with tractors. Most of the farms which had starting problems or troubles in fuel supply in cold winter used light oil for summer. spring or fall rather than for winter. 2. As the result of fuel supply test, fuel supply was stopped at -6$^{\circ}C$ and -18$^{\circ}C$ for summer light oil and winter light oil. respectively 3. The lowest temperatures of winter light oil for starting engine were -7.5$^{\circ}C$ for power-tiller. -12.5$^{\circ}C$ for tractor of 38ps, and -17.5$^{\circ}C$ for tractor of 45ps. which were 5~7.5$^{\circ}C$ lower than that of summer light oil. 4. The performance of engine starting and the trouble of fuel supply system at lower temperature were significantly improved by using winter hight oil rather than summer light oil.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.329-334
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• 2001

Many of past studies using physically based numerical climate models indicate that increases in atmospheric $CO_2$could enhance summer dryness over continental region in middle-high latitudes. However the models used in those studies do not take account of permafrost in high latitudes. We have carried out a set of experiments applying a version of global climate model that can reproduce realistic distribution of the permafrost. From the results, it is indicated that permafrost functions as a large reservoir in hydrologic cycle maintaining dry, hot summer over continents in northern middle-high latitudes, and that the $CO_2$warming would reduce this function by causing climatological thawing of permafrost, which would result in moister and cooler summer, and warmer winter in the same region. The present study indicates that an inclusion of very simple description of soil freezing process can make a large difference in a model simulation.

• Advances in Energy Research
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• v.8 no.3
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• pp.185-202
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• 2022

This research work focuses to design and simulate a 200W solar power system with electrical power conservation scheme as well as thermal power conservation modeling to improve power extraction from solar power plant. Many researchers have been already designed and developed different methods to extract maximum power while there were very researches are available on improving solar power thermally and mechanically. Thermal parameters are also important while discussing about maximizing power extraction of any power plant. A specific type of coolant which have very high boiling point is proposed to be use at the bottom surface of solar panel to reduce the temperature of panel in summer. A comparison between different maximum power point tracking (MPPT) technique and proposed MPPT technique is performed. Using this proposed Thermo-electrical MPPT (TE-MPPT) with Deep Learning Algorithm model 40% power is conserved as compared to traditional solar power system models.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.417-419
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• 2005

This paper presents the effects and the regional power distribution of an increase or a decrease of a power reserve by load flow calculations under seasonal load patterns of each country for the future power shortages faced by the metropolitan areas or by the southeastern area of the South Korea in North-East Asia. In these connections, the types of a power transmission for interconnection consist of the 765kV HVAC and the HVDC. In this paper, the various cases of the power system interconnections in Far-East Asia are presented, and the resulting interconnected power systems are simulated by means of a power flow analysis performed with the PSS/E 28 version tool. The power flow map is drawn from data simulated and the comparative study is done. In this future, a power flow analysis will be considered to reflect the effects of seasonal power exchanges And the plan of assumed scenarios will be considered with maximum or minimum power exchanges during summer or winter in North-East Asia countries.

• Journal of Environmental Health Sciences
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• v.33 no.2 s.95
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• pp.83-91
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• 2007

This study investigated the health effects of offensive odor in residents living near the petrochemical industry complex area(PICA) and the thermoelectric power plant(TPP) by using questionnaire. Residents who felt the offensive odor were 58.3% at PICA, 50.9% at TPP and 24.4% at classical fishing and agrarian villages (CFAV)(p=0.000). People who answered that the offensive odor was sever at CFAV were 95.2% only on summer, but at PICA and TPP, were 44.1% and 57.3% on Spring, 62.4% and 68.8% on Summer, 22.0% and 31.7% on Autumn, and 21.7% and 25.7% on Winter, respectively. Average days that the odor occurred were 4.4 days/month at CFAV, but 12.0 and 9.5 days/month at PICA and TPP, respectively. People who experienced the sleep disturbance were 28.0% and 27.1% at PICA and TPP, respectively. The most frequently subjective symptoms were headache(0.953), frequently sneezing(0.825), itchy eyes(0.766), and stimulating eyes(0.709) at PICA, and headache(1.082), itchy eyes(0.931), itchy skin(0.826), and frequent sneezing(0.674) at TPP, respectively. At PICA and TPP, the occurrence rates of diseases in respondents' families were 15.4% and 15.6% for asthma, 12.4% and 9.2% for respiratory diseases, 27.8% and 31.2% for skin diseases, and 9.1% and 6.9% for nervous diseases, respectively. In conclusion, many residents who living near the PICA and TPP experienced the offensive odor during four seasons, especially high on summer, the most frequently subjective symptoms such as headache, itchy and stimulating eyes, frequently sneezing, and some diseases among their families such as asthma, respiratory diseases, skin diseases, and nervous diseases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1415-1422
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• 2018

In Korea, prior to 2011, the electric reserve margin followed the probabilistic reliability view and the planning reserve margin had been operated at about 15% based on the assumption that power outage was permitted within 0.5 days a year. However, after experiencing the shortage of the electric generation capacity in Sept. 15, 2011, the planning reserve margin was selected as 22% to improve the reliability of the electric supply. In this paper, using panel data of 28 OECD countries over the period 2000-2014 we attempted to empirically examine the linkage between reserve margin, electricity tariffs, renewable energy share, GDP per capita, and summer / winter peak-to-peak ratios. As a result, all four independent variables have been significant for the electric reserve margin, and in particular, we found that countries with similar peaks in winter and summer have operated 4.3% higher reserve margin than countries experiencing only summer peak.