• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2959-2973
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• 2021

In wireless sensor and actuator networks (WSANs), the network lifetime is an important criterion to measure the performance of the WSAN system. Generally, the network lifetime is mainly affected by the energy of sensors. However, the energy of sensors is limited, and the batteries of sensors cannot be replaced and charged. So, it is crucial to make energy consumption efficient. WSAN introduces multiple actuators that can be regarded as multiple collectors to gather data from their respective surrounding sensors. But how to deploy actuators to reduce the energy consumption of sensors and increase the manageability of the network is an important challenge. This research optimizes actuators deployment by a proposed probabilistic mutation multi-layer particle swarm optimization algorithm to maximize the coverage of actuators to sensors and reduce the energy consumption of sensors. Simulation results show that this method is effective for improving the coverage rate and reducing the energy consumption.

• 대한건축학회논문집:구조계
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• 제34권7호
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• pp.27-34
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• 2018

The energy consumption of apartment houses is affected by various factors. The criteria for assessing current energy usage are area, region and purpose. The purpose of this study is to obtain the reliability of the method of evaluating the existing energy consumption certificate and to derive usable evaluation factors according to the correlation of factors affecting energy consumption. The research process collects energy usage data for apartment houses in Daegu and calculates statistical results through correlation analysis and multiple regression analysis. As a result, it was found that the power energy is influenced by the yearly factor of physical characteristics, and the heat energy and total energy usage are influenced by the energy source which is energy characteristic factor.

• Asian Journal of Atmospheric Environment
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• 제8권1호
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• pp.48-58
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• 2014

Energy efficiency is vital to improve energy security, environmental and social sustainability, and economic performance. Improved energy efficiency also mitigates climate change by lowering greenhouse gas (GHG) emissions. Buildings are the single largest industrial consumer of energy and are therefore key to understanding and analyzing energy consumption patterns and the opportunities for saving energy at the district level in urban environments. This study focused on two representative boroughs in the major metropolitan area of Seoul, South Korea as a case study: Gandong-gu, a typical residential district, and Jung-gu, a typical commercial district. The sources of the energy supplied to the boroughs were determined and consumption patterns in different industry sectors in Seoul used to identify current patterns of energy consumption. The study analyzed the energy consumption patterns for five different building categories and four different sectors in the building using a bottom-up energy modeling approach. Electricity and gas consumption patterns were recorded for different building categories and monthly ambient temperatures in the two boroughs. Finally, a logarithmic equation was developed to describe the correlation between commercial activity and cooling energy intensity in Jung-gu, the commercial district. Based on these results, recommendations are made regarding the current energy consumption patterns at the district level and government energy policies are suggested to reduce energy consumption and, hence, greenhouse gas emissions, in both commercial and residential buildings.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.101-109
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• 2018

In this paper, we propose an adaptive filtering scheme of connection requests for the defense of malicious energy consumption attacks against wireless computing devices with limited energy budget. The energy consumption attack tries to consume the battery energy of a wireless device with repeated connection requests and shut down the wireless device by exhausting its energy budget. The proposed scheme blocks a connection request of the energy consumption attack in the middle, if the same connection request is repeated and its request result is failed continuously. In order to avoid the blocking of innocuous mistakes of normal users, the scheme gives another chance to allow connection request after a fixed blocking time. The scheme changes the blocking time adaptively by comparing the message arriving ate during non-blocking period and that during blocking period. Evaluation shows that the proposed defense scheme saves up to 94% energy consumption compared to the non-defense case.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.706-707
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• 2015

Our country is aiming at 30% reductions in building energy consumption accounting for 39% of the total energy consumption by 2020[1]. For this purpose, the government is developing and applying the Building Energy Management System (hereinafter, referred to as "BEMS", Smart plug, etc.) while the researches on new renewable energy development. BEMS, which is applied with focus on large buildings, is inducing energy management of the entire building through energy measurement and data management, but considering its economic efficiency, it's very difficult to apply BEMS to small & medium-size buildings. Hereupon, this study intends to implement the case analysis of deterioration and economic efficiency of major equipment in buildings on the basis of electricity consumption which has been measured targeting small & medium-size buildings for a certain period by taking into account that equipment deterioration is a contributor to the increase in energy consumption.

• 한국지열·수열에너지학회논문집
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• 제7권2호
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• pp.16-22
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• 2011

Since 1970s, energy-saving design criteria of buildings has been improved through numerous revisions. The purpose of this research is to show how energy saving design criteria affects heating energy consumption of apartments using district heating. Heating energy consumption has been measured in 4 apartments located in Gyeonggi province, Korea from Nov. 1,2007 through Oct. 31, 2008. Collected data was regressed to linear correlations. Heating energy consumptions were calculated for past, present and future energy-saving design criteria, which are outdoor temperature, ventilation and insulation. The results show that present design criteria has reduced heating energy consumption by 15%, and the future criteria will reduce the energy consumption by 42% compared to the criteria before 2001.

• 설비공학논문집
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• 제26권8호
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• pp.394-400
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• 2014

Several models and methods have been developed to verify the improvement of energy performance in retrofit buildings. The verification is important to confirm the effectiveness of new technologies or retrofits. Inverse model toolkit proposed by ASHRAE evaluates the changes of the energy performance of retrofit buildings by using actual energy consumption data. In this study, the inverse model toolkit was used to analyze heating and cooling energy performance of an office building. Analyzed coefficients of correlation of actual energy consumption with estimated energy consumption was above 0.92 and well fitted. It was confirmed that energy consumption of natural gas decreased by 43.4% and also that electricity decreased by 13.8%, after the retrofit of the case building. For the energy usage, cooling energy was increased by 7.4%, heating energy was decreased by 42.3%, hot water and cooking were increased by 3.4%, lighting and electronics were decreased by 19.3%, and the total energy was decreased by 18.9%.

• 한국지열·수열에너지학회논문집
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• 제9권4호
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• pp.1-7
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• 2013

This study is to compare energy consumption of air-source, ground-source and dual-source heat pump systems during intermediate season using dynamic simulation. Ground-source heat pump has higher COP than that of air-source but requires additional power consumption of auxiliary equipment such as circulation pump. During intermediate season when the outdoor air temperature is favorable, total COP of air-source heat pump may be greater than that of ground-source when circulation pump power consumption is included. Dual-source heat pump which selects the more favorable heat source is compared with air-source only and ground-source only heat pumps for total power consumption. Results show that power consumption of dual-source heat pump is lower than that of ground-source only by 0.73%.

• 대한산업공학회지
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• 제41권5호
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• pp.414-424
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• 2015

In this research, we consider a smart grid network of electricity with multiple consumers connected to a monopolistic provider. Each consumer can be informed the real time price changes through the smart meter and updates his consumption schedule to minimize the energy consumption expenditures by which the required power demand should be satisfied under the given real time pricing scheme. This real-time decision making problem has been recently studied through game-theoretic approach. The present paper contributes to the existing literature by incorporating storage appliance into the set of available household appliances which has somewhat distinctive functions compared to other types of appliances and would be regarded to play a significant role in energy consumption scheduling for the future smart grid. We propose a game-theoretic algorithm which could draw the optimal energy consumption scheduling for each household appliances including storage. Results on simulation data showed that the storage contributed to increase the efficiency of energy consumption pattern in the viewpoint of not only individual consumer but also whole system.

• 국토계획
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• 제53권6호
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• pp.101-116
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• 2018

Paying an attention to the issue of energy poverty of low-income households and ensuing regressivity of energy consumption, this study empirically analyzes the effects of both household and housing characteristics on heating energy consumption in an integrated way and identifies their causal structure based on the 2016 Korea Housing Survey data provided by the Korean government. Multiple regression analysis shows that household income and deteriorated level of housing, such as age and degree of cracks have positive effects and floor area of housing has a negative effect on the heating energy consumption per unit area of housing (HECPUH). Path analyses further reveal that the direct effect of household income on HECPUH is offset by the indirect effects that are mediated by deteriorated level and floor area of housing, making the total effect statistically insignificant. As a result, there is no significant difference in HECPUH across all income strata, implying that low-income (high-income) households pay more (less) heating costs relative to their income level, since they reside in the houses with relatively low (high) energy efficiency. To deal with this regressive causal structure of energy consumption, a policy option is recommended to improve energy efficiency of low-income housing through the government assistance in its maintenance and repair.