• Journal of Energy Engineering
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• 제8권4호
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• pp.567-575
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• 1999

This study found potential ability to generate electric power using difference in water temperature between sea surface water and deep water in the East Sea which includes the East Sea Proper Water with the temperature less than 1$^{\circ}C$ throughout a year without seasonal variation. To quantify the difference in water temperature between sea surface water and deep water in the East Sea. We computed the annual mean ($^{\circ}C$), the annual amplitude ($^{\circ}C$), the annual phase (degree) and the duration time which showed more than 15$^{\circ}C$ temperature difference from the water temperature data using Harmonic analysis during 1961~1997. The best place for generating electric power in the East Sea seems to be the eastward ocean areas (36$^{\circ}$ 05'N, 129$^{\circ}$ 48'E~36$^{\circ}$ 05'N, 130$^{\circ}$ 00E'E) from Pohang city. The annual mean of the difference in water temperature between sea surface water and 500 m depth was 24$^{\circ}$C at the place to generate electric power in August according to the data of 1961~1997. the maximum duration periods with more than 15$^{\circ}C$ temperature difference were 215 days (5/5-12/10) a year in the place mentioned electricity with a stable plan. In the East Sea coastal areas of the Korean peninsula, the average minimum depth to reach the East Sea Proper Water from surface water is 300 m and fluctuates between 250 m and 350 m throughout a year. Further studies could be needed for the utilization of cold water, such as the East Sea Proper Water for energy conversion.

• Journal of the Korean Institute of Rural Architecture
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• 제24권1호
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• pp.9-17
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• 2022

Rural spaces are increasingly valuable as areas for introducing renewable energy infrastructure to achieve carbon neutrality. Rural areas are the living grounds of rural residents, and the balance of conservation and development for rural areas is important for the introduction of reasonable facilities. In order to maintain a balance between development and preservation and to introduce reasonable renewable energy facilities, it is necessary to develop a current status survey and an effective survey method to utilize a space capable of introducing renewable energy facilities such as idle land and vacant houses. Therefore, this study was conducted to verify the readability using an unmanned aerial vehicle, and the main results are as follows. The detection of photovoltaic power generation facilities using unmanned aerial vehicles was effective in analyzing the location and area of photovoltaic panels located on the roofs of buildings, and it was possible to calculate the expected power generation by region through the area calculation of photovoltaic panels. The vacant house detection can be used to select an investigation target for an vacant house condition survey as it can identify damage to buildings that are expected to be empty houses, management status, and electricity supply facilities through aerial photos. It is judged that the unmanned aerial vehicle detection capability can be utilized as a method to improve the efficiency of investigation and supplement the data related to solar power generation facilities and vacant houses provided by public institutions. Although this study detected the status of solar power generation facilities and vacant houses through high-resolution aerial image analysis, as a follow-up study, automatic measurement methods using the temperature difference of solar power generation facilities and general characteristics of vacant houses that can be read from the air were investigated. If the deriving research is carried out, it is judged that it will be possible to contribute to the improvement of the accuracy of the detection result using the unmanned aerial vehicle and the expansion of the application range.

• Journal of the Korean Society for Railway
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• 제15권4호
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• pp.408-412
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• 2012

Recently, new climate change mechanism after 2020 year has been accepted with the parties, and so government is pushing ahead the GHG reduction policies to achieve the effective results. Especially, it is essential to enhance the role of railroad in the public traffic system as well as to develop new cars with high energy efficiency for the GHG reduction of transportation sector. Thus, the calculation method of GHG emission of railroad should be established to manage the emission continuously. In this study, the calculation method of GHG emission of railroad was defined with Tier level considering its emission sources to refer to 2006 IPCC guideline for national GHG inventories. Also, the GHG emission of railroad at Tier 1 level was investigated using the activity data related to the amount of diesel and electricity consumption from 2008 to 2010. As a result, total GHG emission in 2010 was about 2,060 thousands ton CO2e, which have 73% of electricity and 27% of diesel. In future, the plans on the GHG reduction of railroad will be accomplished by the analysis of the detailed trends on the basis of the emission management of Tier 3 level under operating patterns. Therefore, it is important to develop the specific GHG emission factors of railroad in advance.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• 제47권1호
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• pp.24-34
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• 2015

Domestic companies supplying electricity must increase obligatory duty to use renewable energy annually. If not met with obligatory allotment, the electricity-supply companies must pay RPS (Renewable Portfolio Standards) penalty. Although the power plants using a pulverizing coal firing boiler could co-fire up to around 3 per cent with wood pellets mixed in with coal feedstock without any major equipment revamps, they recorded only about 60 per cent fulfillment of RPS. Consequently, USD 46 million of RPS penalty was imposed on the six power supplying subsidiaries of GENCOs in 2014. One of the solutions to reduce the RPS penalty is that the power supply companies adopt the co-firing of torrefied lignocellulosic biomass in coal plants, which may contribute to the use of over 30 per cent of torrefied biomass mixed with bituminous coals. Extra binder was required to form pellets using torrefied biomass such as wood chips, PKS (Palm Kernel Shell) and EFB (Empty Fruit Bunch). Instead of corn starch, 30, 50 and 70 per cent of Larix saw dusts were respectively added to the torrefied feedstocks such as Pinus densiflora chips, PKS and EFB. The addition of saw dusts led to the decrease of the calorific values of the pellets but the forming ability of the pelletizer was exceedingly improved. Another advantage from the addition of saw dusts stemmed from the reduction of ash contents of the pellets. Finally, it was confirmed that torrefied oil palm biomass such as PKS and EFB could be valuable feedstocks in making pellets through improved binding ability.

• Journal of the Institute of Electronics and Information Engineers
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• 제52권7호
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• pp.135-142
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• 2015

Human-powered self-generating devices have been attractive with its operation characteristic independent from outer environment such as weather condition and wind speed. However, conventional self-generators have low electric power output due to their weakly-coupled electromagnetic structure. More importantly, rotary crank motion which is usually adopted by conventional self-generator to generate electricity requires specific skeletal muscles to maintain large torque circular motion and consequently, causes fatigue on those muscles before it can generate enough amount of electricity for any practical application. Without improvement in electric power output and usability, the human-powered self-generator could not be used in everyday life. This study aims to develop a human-powered self-generator which realized a strong electromagnetic coupling in a closed-loop tubular structure (hula-hoop shape) for easy and steady long-term driving as well as larger electric output. The performance and usability of the developed human-powered generator is verified through experimental comparison with a commercial one. Additionally, human workload which is a key element of a human-powered generator but not often considered elsewhere, is estimated based on metabolic energy expenditure measured respiratory gas analyzer. Further study will focus on output and portability enhancement, which can contribute to the continuous power supply of mobile equipments.

• The Journal of Bigdata
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• 제4권1호
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• pp.63-72
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• 2019

For power energy, optimal generation and distribution plans based on accurate demand forecasts are necessary because it is not recoverable after they have been delivered to users through power generation and transmission processes. Failure to predict power demand can cause various social and economic problems, such as a massive power outage in September 2011. In previous studies on forecasting power demand, ARIMA, neural network models, and other methods were developed. However, limitations such as the use of the national average ambient air temperature and the application of uniform criteria to distinguish seasonality are causing distortion of data or performance degradation of the predictive model. In order to improve the performance of the power demand prediction model, we divided Korea into five major regions, and the power demand prediction model of the linear regression model and the neural network model were developed, reflecting seasonal characteristics through regional characteristics and migration period learning techniques. With the proposed approach, it seems possible to forecast the future demand in short term as well as in long term. Also, it is possible to consider various events and exceptional cases during a certain period.

• Environmental and Resource Economics Review
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• 제24권3호
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• pp.463-488
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• 2015

A more detailed design of offset system is needed according to the emission trading system started in 2015. This study aims to estimate the supply of potential offset that can be secured by expanding high-efficiency household electric appliances. The target commodities for analysis are three different householding electric appliances: TV, washing machine, electric fan, refrigerator and air conditioner. By using the ARDL model, we estimated the coefficients of diffusion of these high-efficiency appliances from 2016 to 2022. Then, the potential supply of offset was drawn by calculating the amount of electricity saving by efficiency improvement and by applying the rates of carbon exchange. Supposing that the electricity savings rates of high-efficiency appliances are each 10% and 20%, the accumulated carbon decrement in 2022 was respectively $361,899CO_2t$ and $723,797CO_2t$. The appliance that showed the biggest carbon decrement was air conditioner, and the second biggest was refrigerator and the next was TV, followed by washing machine, electric fan.

• Fire Science and Engineering
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• 제31권2호
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• pp.61-73
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• 2017

The Fukushima Nuclear Disaster in 2011 and California Power Failure in 2001 are examples of the importance of the power plant safety management that caused huge national loss with a power-related mass casualty incident. In a situation where humans cannot live without electricity, efforts to strengthen the systematic firefighting safety management in power plants that produce electricity with large amounts of hazardous materials as fuel, such as nuclear energy, coal and gas, are essential to protect life and prevent property loss and stable economic growth from fire explosion accident or radiation leak due to the negligence of safety management and natural disasters such as earthquakes, which has recently become an issue. This study examined the operating situation of firefighting safety management in power plants with firefighting officials employed by five power generation companies including Korea Southern Power Co., Ltd. and Korea Hydro & Nuclear Power Co. Ltd., which are in charge of the domestic power supply. As a result, for the systematic firefighting safety management of power plants, improvement plans were drawn, including the development of an effective business manual and a comprehensive management system, the substantiality of firefighting safety education, and the strengthening of seismic designs to prepare for earthquakes.

• Journal of The Korean Association For Science Education
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• 제21권1호
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• pp.30-37
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• 2001

The importance of integrated approach have increased gradually in science education. But most of researches on integrated science have been based on the structure of science and epistemology. The investigations of students' psychological science domains are needed for effectiveness of integrated science in science curriculum and classrooms. In this study, for exploration of elementary school students' psychological science domains and their properties, students(N=96) were asked to classify scientific words presented on textbooks in several categories. Many psychological science domains were revealed. Among them, the domains that were over 20% are 'Electricity', 'The human body', 'The earth', 'Energy', 'Plant', 'Animal', 'Environment', 'Living things', 'Weather', 'Flower'. According to the results from analysis on the words that students presented in each domains, the participants hold strongly the relationships caused by everyday experiences. For example, 'light' and 'heat' showed high frequency in 'Electricity' domain and 'The human body' domain included 'force' and 'motion' in high frequency. The most inclusive domain was 'The earth'. Not only the words on earth science but also biological and chemical words were classified in this domain. So The integration that centered with 'The earth' domain looks correspond to the elementary school students' psychological aspect.

• Korean Chemical Engineering Research
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• 제48권2호
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• pp.224-231
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• 2010

In GvdW EOS, a recently presented paper, shows that the characteristic status for spherical non-linear particle, of which the mutual behavior is known to be vdWf(van der Waals force) only, could be described well enough in the critical region. However, in current papers, analysis has not been done on GvdW about whether it is accurate or not, even for the particles in the linear form or those with the additional mutual behavior such as static-electricity, so there's some argument about the wide use of that. Therefore, in this paper, for the simulation in the critical region of Normal-alkane group(R=methane, ethane, propane, butane) which are the particles that has a linear charateristic and Normal-amine group($RNH_2$, R=methyl-, ethyl-, propyl-amine) where static-electricity is extremely shown, GvdW parameter values about these particles are defined, and based on this simulation, we compared results to the current EOS presented recently, and analyzed them. Through the simulation, it was shown that in case of Normal-alkane group and Normal-amine group molecules, GvdW presents an accurate critical region characteristic which is far more close to the measurement compared to current EOSs. Especially for butane with big amount in molecules, we found out that only GvdW EOS can reach close enough to the critical point.