• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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• pp.129-133
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• 2003

The work described in this paper deals with the proposed application of an Artificial Neural Network Model for the Advanced Pressurized Water Reactor APR-1400 transient identification. The approach adopted for testing the network take note of the expectation which should be fulfilled by a network for real-time application, like testing with data in on-line mode and use of actual or real-life patterns for training. The recall test performed demonstrates that use of neural network for transient identification is indeed an attractive preposition.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.401-407
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• 2022

Central heating, ventilation and air conditioning (HVAC) is one of the largest consumers of energy in the residential sector. This project explores the use of multiple HVAC units and/or Zoning in a single residence to reduce energy loads. The energy consumption data of a detached single-family home using two HVAC units, one primary for the main house and a secondary HVAC for a casita, was collected for the same month for two consecutive years, along with details related to the outdoor temperature and the square footage being air-conditioned by each HVAC. A regression algorithm was trained using the above details to find the relation between the parameters. Next, based on the occupancy and usage patterns, the HVAC was redesigned assuming more area under the secondary HVAC unit. The trained algorithm was then used to make energy usage predictions for the revised primary HVAC area, with the assumption that the secondary HVAC unit was turned off. The results were compared with existing energy usage data. It was determined that there were significant energy savings in the second scenario. It is expected that this study and its findings will help future research projects explore more ideas as alternatives to central HVAC, in improving the economic viability of existing options, and in developing a savings calculation tool that will help consumers make informed decisions on their best alternatives to central HVAC.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.754-760
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• 2011

In the DC traction system, a large load current of electric railcar leads to a voltage drop when a vehicle starts, and the regenerative power generated by brake system increases the catenary voltage. To minimize the voltage fluctuation during the train operation and make use of the regenerative power, several types of energy storage systems are being studied. The energy storage system that is being recently introduced consists of the supercapacitors for energy storage and the bi-direction DC/DC converter for charge/discharge control. The efficiency of the energy storage system depends on the train operation pattern. In this paper, the operation efficiency of the energy storage system was quantitatively analyzed via simulation study taking consideration of the train operation patterns. The simulation was conducted changing the headway of trains with the energy storage system that uses the bi-direction DC/DC converter and supercapacitor. The simulation results showed that the operation efficiency of the energy storage system increases as the headway increase.

• 에너지공학
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• 제27권2호
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• pp.61-69
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• 2018

Rare earth elements together with Y and Sc (REEs) are essential in the development of technology for clean and efficient use of energy. In recent years coal deposits have much attention and attracted as a promising alternative raw sources for rare earth elements, not only because the REEs concentrations in many coals or coal ashes are equal to or higher than those found in conventional types of REEs ores but also because of the world wide demand for REEs in recent years has been greater than supply. In the coal ashes, REEs are mainly associated with carbonates, silicates and aluminosilicates in ashes at 800 and $1100^{\circ}C$. These elements are known to be powerful environmental tracers in natural biogeochemical compartments. In this study, to reviewed the REEs originating and distribution patterns in coal ash samples from the bedrock and/or soil weathering that were entrapped by lichens and mosses was investigated. The REEs patterns of different organisms species allowed minor influence of the species to be highlighted compared to the regional lithology.

• 대한산업공학회지
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• 제42권2호
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• pp.96-111
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• 2016

Effort to reduce energy consumptions or CO2 emissions is global trend. To follow this trend, spatial studies related to characteristics affecting energy consumptions or CO2 emissions have been conducted, but only with the focus on spatial dependence, not on spatial heterogeneity. The aim of this study is to investigate spatial heterogeneity patterns of CO2 emission based on socio-economic factors, land-use characteristics and traffic infrastructure of Seoul city. Geographically Weighted Regression (GWR) analysis was performed with 423 administrative district data in Seoul. The results suggest that population and employment densities, road density and railway length in most districts are found to have positive impact on the CO2 emissions. Residential and green area densities also have the highest positive impact on CO2 emissions in most districts of Gangnam-gu. The resulting model can be used to identify the spatial patterns of CO2 emissions at district level in Seoul. Eventually it can contribute to local energy policy and planning of metropolitan area.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.367-378
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• 2021

This paper develops a dynamic regression model to quantify the contribution of key external factors to operational energy efficiency of ships. On this basis, kernel density estimation is applied to explore distribution patterns of fluctuations in operational performance. An empirical analysis based on these methods show that distribution of fluctuations in Energy Efficiency Operational Indicator (EEOI) is leptokurtic and fat tailed, rather than a normal one. Around 85% of fluctuations in EEOI can be jointly explained by capacity utilization and sailing speed, while the rest depend on other external factors largely beyond control. The variations in capacity utilization and sailing speed cannot be fully passed on to the energy efficiency performance of ships, due to complex interactions between various external factors. The application of the methods is demonstrated, showing a potential approach to develop a rating mechanism for use in the legally binding framework on operational energy efficiency of ships.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.807-813
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• 2012

In this paper, we introduce data mining techniques for short-term load forecasting (STLF). First, we use the K-mean algorithm to classify historical load data by season into four patterns. Second, we use the k-NN algorithm to divide the classified data into four patterns for Mondays, other weekdays, Saturdays, and Sundays. The classified data are used to develop a time series forecasting model. We then forecast the hourly load on weekdays and weekends, excluding special holidays. The historical load data are used as inputs for load forecasting. We compare our results with the KEPCO hourly record for 2008 and conclude that our approach is effective.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.59.2-59.2
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• 2011

This study presents a new method for coupling ArcGIS (popular GIS software) with TRaNsient SYstems Simulation (TRNSYS, reference software for researchers and engineers around the world) to use capabilities of the 4 and 5-parameter PV array performance models within the ArcGIS environment. Using the validated and industry-proven solar energy simulation models implemented in TRNSYS and other built-in ArcGIS functionalities, dynamic characteristics of distributed PV potential in terms of hourly, daily or monthly power outputs can be investigated with considerations of diverse options in selecting and mounting PV panels. In addition, the proposed method allows users to complete entire procedures in a single framework (i.e., a preliminary site survey using 3D building models, shading analyses to investigate usable rooftop areas with considerations of different sizes and shapes of buildings, dynamic energy simulation to examine the performances of various PV systems, visualization of the simulation results to understand spatially and temporally distributed patterns of PV potential). Therefore tedious tasks for data conversion among multiple softwares can be significantly reduced or eliminated. While the programming environment of TRNSYS is proprietary, the redistributable executable, simulation kernel and simulation engine of TRNSYS can be freely distributed to end-users. Therefore, GIS users who do not have a license of TRNSYS can also use the functionalities of solar energy simulation models within ArcGIS.

• KIEAE Journal
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• 제11권3호
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• pp.19-30
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• 2011

This study examined apartment residents' energy-lifestyle, and their energy consumption patterns by energy-lifestyle. The major findings are as follow: 1)In order to identify energy lifestyle, three dimensions - value of life, energy consuming behavior and energy awareness - were defined by literature reviews, and each dimension was tested to define components. 2)The scores of the 14 factors that were defined by factor analysis on the three dimensions of the energy lifestyle were subject to cluster analysis, and then lifestyle was categorized into five groups. G1 is very negative, and indifferent to energy waste or saving at home. G2 is passively carrying out energy saving activities at home, only within their comfort. G3 is aware of energy saving, and more actively keeping energy saving behavior in their everyday lives, while they also show energy waste behavior at the same time. G4 is particularly indifferent to energy costs, and presenting energy squandering behaviors. G5 is better aware of energy saving than other groups, and carrying out energy saving behaviors in their everyday lives. This study would be of help to establish energy saving management and education plans in apartments.

• 한국유기농업학회지
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• 제9권4호
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• pp.53-69
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• 2001

The word \"permaculture\" is a contraction of \"permanent agriculture\" or \"permanent culture\". Permaculture principles are designed to support (or ensure) the survival of humanity, the earth and all on it, and, to improve our standard of living, Permaculture can be defined as : a design system for creating sustainable human environments that can be (relatively) easily constructed and maintained. The principles of permaculture designs are relative location every element (such as house , rice paddy, road, esc) is placed in relation to each other such that each assists the other : each element performs multiple functions ; each function is supported by many elements : energy efficient planning ; using biological resources rather than fossil fuels : energy cycling on site (both fuel and human energy) : Using and accelerating natural plant succession to establish favourable sites and soils ; poly-culture and diversity of beneficial species for a productive, interactive system ; use of edge and natural patterns for best effect. These principles can be used for any permaculture design, in any climate, and at any scale. There has been very little scientific examination of Permaculture, and as such, it must be viewed as a design philosophy.viewed as a design philosophy.