• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.12
• /
• pp.5712-5728
• /
• 2017

Recently, there are many studies, that considering green wireless cellular networks, have taken the energy consumption of the base station (BS) into consideration. In this work, we first introduce an energy consumption model of multi-mode sharing BS powered by multiple energy sources including renewable energy, local storage and power grid. Then communication load requests of the BS are transformed to energy demand queues, and battery energy level and worst-case delay constraints are considered into the virtual queue to ensure the network QoS when our objective is to minimize the long term electricity cost of BSs. Lyapunov optimization method is applied to work out the optimization objective without knowing the future information of the communication load, real-time electricity market price and renewable energy availability. Finally, linear programming is used, and the corresponding energy efficient scheduling policy is obtained. The performance analysis of our proposed online algorithm based on real-world traces demonstrates that it can greatly reduce one day's electricity cost of individual BS.

• Proceedings of the KIEE Conference
• /
• 2002.07a
• /
• pp.441-443
• /
• 2002

This paper presents a window-based load management system (LMS) package developed as a decision-making tool in the competitive electricity market. The presented LMS package can help the users to monitor system load patterns, analyze their past energy consumption and schedule the future energy consumption. The LMS package can also provide the effective information on real-time energy/cost monitoring, consumed energy/cost analysis, demand schedule and cost-savings. The developed LMS package can be used to establish the optimal demand schedule and consumption strategy.

• International Journal of Advanced Culture Technology
• /
• v.3 no.1
• /
• pp.78-85
• /
• 2015

In Thailand, the electricity consumption is very high with the intention of reduce high temperature in the building. Since 2000, a lot of people paying attention to Green-Building concept. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally. Therefore, the Earth-Block (EAB) product is appropriated approach to reduce energy consumption in the buildings. The EAB is produced with environmentally friendly process, which does not release harmful pollution and effective cost. The main significant character is durable materials for building construction. This study aims to develop the new thermal insulation by using soil-cement with vetiver grass fibre. Additionally, it describes the innovative systems used in production of EAB materials by mixing the soil-cement with vetiver grass fibre. This paper reveals lowest costs, space configurations changing and greater design flexibility for constructing the building.

• Korea Science and Art Forum
• /
• v.19
• /
• pp.561-568
• /
• 2015

A lot of electrical energy is used in our daily life. While energy saving concerns are overall, consumption practices of people in general are very different. People want to control their energy use and by knowing the amount of energy they use. Smart plug is a new device that measures electricity usage through each plug at an outlet with on/off control. User experience for electrical devices in regards to electricity usage should be newly designed. In this study, based on the survey, personas have been devised and their energy use experience in relation with smart plugs have been designed. Service models have been designed as well. By designing service with smart plug, user could enhance the experience of energy usage and saving and energy consumption practices could be improved in a sustainable manner.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.4
• /
• pp.75-81
• /
• 2014

In this paper we made energy consumption units of glass curtain wall type apartment and general apartment in Busan metropolitan city and compared energy consumption characteristics by building envelope. The monthly electricity consumption units of general apartment were shown in the range of $1.16{\sim}1.51kWh/m^2{\cdot}mon$ which were indicated higher value in January, February, August and September with little variation. On the other hand, in case of glass curtain wall type apartment, monthly electricity consumption units were represented in the range of $1.91{\sim}7.07kWh/m^2{\cdot}mon$ with significant fluctuations monthly, which were outstandingly high in July, August and September. The monthly city gas consumption units of general apartment were found to be in the range of $1.79{\sim}18.07MJ/m^2{\cdot}mon$, while glass curtain wall type apartment were within $0.94{\sim}19.91MJ/m^2{\cdot}mon$. City gas consumption units from December to March were shown highly in both type apartments. The monthly energy consumption units of general apartment were found to be within $14.23{\sim}30.69MJ/m^2{\cdot}mon$, while glass curtain wall type apartment were within $24.49{\sim}68.9MJ/m^2{\cdot}mon$. Energy consumption units of glass curtain wall type apartment were suggested 4.84 times higher than those of general apartment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.10
• /
• pp.733-738
• /
• 2012

It is important issue to reduce the electric energy to save the operating cost of HVAC system. Even if electrical energy is the clean energy, it is difficult and takes high cost for storage of electricity. These cause the high peak load of electric energy for HVAC in summer season. In korea, government impose the electric charge with several grade for the purpose of cut-off the peak load of electricity. Government has a policy to support to design and install the heat/ice storage system using midnight electricity. In this study, analysis of cooling load and operating characteristics for ice storage system are performed. And, also economical efficiency is compared between ordinary charge system of electricity and midnight rate charge of electricity. The systematic and economical supports are needed for expansion of usage of energy saving equipments.

• Journal of Digital Convergence
• /
• v.14 no.7
• /
• pp.193-200
• /
• 2016

Research and development of energy self-consumption introducing photovoltaic and energy storage system at home is very active. This system can manage the home energy in which it charges the electricity generated during the day and uses it during high electricity bills. However, it not yet made up the residential real-time pricing in Korea but it can reduce electricity usage to a certain target on the progressive. In order to introduce the home photovoltaic, it requires PCS(Power Conditioning System). This converts the direct current into alternating current by the electricity generated and used to perform charging and discharging of the energy storage system. The market for self-consumption smart home system is currently increasing because the interests of the general public about solar power, energy storage systems increased. The result of this study is installed on the room environment and the effect was analyzed on the assumption of real-time pricing.

• Journal of Energy Engineering
• /
• v.5 no.1
• /
• pp.1-7
• /
• 1996

Coal consumption in Asia is projected to increase by about 1.3 billion tons over the 1993-2010 period. The expansion in coal consumption for electricity generation is the dominant factor in the large increase in coal consumption. Without effective control measures, the projected increase in coal consumption will have a serious impact on environmental effects of increased coal use in Asia. Thus, the introduction of appropriate CCTs is considered essential to achieving the twin goals of expanded use of coal decreased environmental impacts.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.8
• /
• pp.1025-1032
• /
• 2014

The effective energy management method will provide the significant advantage to the residential customers under real time pricing plan since it can reduce the electricity charge by controlling the energy consumption according to electricity rate. The earlier studies for load management mainly aim to minimize the electricity charges and peak power but put a less emphasis on the human comfort dwelling in the residence. The discomfort and displeasure from the energy management only focusing on reduction of electricity charge will make the residential customer reluctant to enroll the real time pricing plan. In this paper, therefore, we propose optimal load control strategy which aim to achieve not only minimizing the electricity charges but also maintaining human comfort by introducing "the human comfort coefficient." Using the human comfort coefficient, the energy management system can reflect the various human personality and control the loads within the range that the human comfort is maintained. Simulation results show that proposed load control strategy leads to significant reduction in the electricity charges and peak power in comparison with the conventional load management method.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.64 no.2
• /
• pp.74-78
• /
• 2015

With the improvement of living standards and economic development, electricity consumption continues to grow. The electricity is a special energy which is hard to store, so its supply must be consistent with the demand. The objective of electricity demand forecasting is to make best use of electricity energy and provide balance between supply and demand. Hence, it is very important work to forecast electricity demand with higher precision. So, various forecasting methods have been developed. They can be divided into five broad categories such as time series models, regression based model, artificial intelligence techniques and fuzzy logic method without considering special-day effects. Electricity demand patterns on holidays can be often idiosyncratic and cause significant forecasting errors. Such effects are known as special-day effects and are recognized as an important issue in determining electricity demand data. In this research, we developed the power demand forecasting method using ELM(Extreme Learning Machine) for special day, particularly, lunar new year and Chuseok holiday.