• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.6
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• pp.283-292
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• 2015

A model of apartment heating load in a district heating system could be useful in the management and utilization of energy resources, since it could predict energy usage and so could assist in the efficient use of energy resources. The heating load in a district heating system varies in a highly nonlinear manner and is subject to many different factors, such as heating area, number of people living in that complex, and ambient temperature. Thus there are few published papers with accurate models of heating load, especially in domestic literature. This work is concerned with the modeling of apartment heating load in a district heating system in winter, using the reduced least square support vector machine (LS-SVM), and with the purpose of using the model to predict heating energy usage in domestic city area. We collected 23,856 pieces of data on heating energy usage over a 12-week period in winter, from 12 heat exchangers in five apartments. Half of the collected data were used to construct the heating load model, and the other half were used to test the model's accuracy. The model was able to predict the heating energy usage pattern rather accurately. It could also estimate the usage of heating energy within of mean absolute percentage error. This implies that the model prediction accuracy needs to be improved further, but it still could be considered as an acceptable model if we consider the nonlinearity and uncertainty of apartment heating energy usage in a district heating system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.119-120
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• 2022

As the seriousness of the climate crisis is emphasized, movements to solve it are becoming active. In Korea, efforts to reduce environmental impacts across all industries are being strengthened through the Framework Act on Low Carbon Green Growth. The construction industry predicts the environmental impact of buildings during the entire life cycle, but in the construction process, there is a difference in energy usage depending on the amount of input, and it is difficult to predict the environmental impact if data cannot be collected. Therefore, this study evaluated the environmental impact of energy usage in the apartment construction process as part of the study on predicting and reducing the environmental impact of the construction process of the construction site. To this end, the environmental effects of buildings were set as global warming, resource consumption, and ozone layer effects, and the environmental effects of the actual energy use in the case were evaluated. In addition, based on the evaluation results, the characteristics of the input energy usage were compared and analyzed.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.65-71
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• 2011

Recently, central and local governments of Korea have established and implemented various energy policies such as making energy map of city level and establishment of environment friendly city plan to materialize low carbon green city. To implement effectively these policies, however, conditions of energy consumption by each administrative district and each usage have to be verified exactly. This study is aimed to suggest a basic data for planing energy policy and energy demand prediction of city level by analyzing energy consumption unit and conditions of city gas by borough and usage in Busan.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.16-22
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• 2016

This paper addresses the load usage scheduling in the HEMS for residential power consumers. The HEMS would lead the residential users to change their power usage, so as to minimize the cost in response to external information such as a time-varying electricity price, the outside temperature. However, there may be a consumer's inconvenience in the change of the power usage. In order to improve this, it is required to understand the pattern of load usage according to the external information. Therefore, this paper suggests a methodology to model the load usage pattern, which classifies home appliances according to external information affecting the load usage and models the usage pattern for each appliance based on a copula function representing the correlation between variables. The modeled pattern would be reflected as a constraint condition for an optimal load usage scheduling problem in HEMS. To explain an application of the methodology, a case study is performed on an electrical water heater (EWH) and an optimal load usage scheduling for EHW is performed based on the branch-and-bound method. From the case study, it is shown that the load usage pattern can contribute to an efficient power consumption.

• Journal of Korea Multimedia Society
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• v.22 no.3
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• pp.366-373
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• 2019

The development of monitoring and analysis systems to increase productivity while saving energy is needed as a method to reduce huge amount of energy consumed in the process of producing large forged products. In this paper, we propose a system to monitor and analyze energy usage in real-time collected from gas-meter, wattmeter, and thermometer based on IoT installed in forging factories. The system consists of a data collection server for collecting and processing data from IoT- based platform and existing SCADA equipment and ERP/MES system in forging factories, and an application server for providing services to users. To develop the system, the overall system structure is logically diagrammed, and the databases configuration and implementation modules to efficiently store and manage data are presented. In the future, the system will be utilized to reduce energy consumption by analyzing energy usage pattern and optimizing process works with real-time energy usage and production process data for each facility.

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

• KIISE Transactions on Computing Practices
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• v.22 no.10
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• pp.513-520
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• 2016

As IoT devices become more common in the public sphere, the energy efficiency of embedded systems becomes a problem of major interest in addition to the system performance. Energy efficiency is important for portable embedded systems because they obtain power from their battery, and a low energy efficiency will result in a low usage time while a high energy efficiency will allow for longer usage time. In this paper, we propose a memory usage based frequency selection method to improve the energy efficiency of embedded Linux systems by using devfreq to select the device's system frequency. In our experiments, we found that the proposed method reduces energy consumption in an embedded device by up to 18%.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.121-126
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• 2009

This study analyzed the standard school's energy usage and patterns as the zero-energy goal of primary school building, and proposed the energy reduction process of school building using energy analysis computing simulation tool. As a analysis simulation tool, Visual DOE 4.0 is used. For analysis of actual energy usage, selected primary school that is standard in the nation's energy consumption. Standard of the school's energy consumption analysis were devided into electric and gas energy. Input parameters of the simulation program based on the literature material and field survey material. after, but it was calibrated to comparison with the standard school's energy consumption. Finally, its energy usage analyzed by component and made the priority order of energy saving. Applied energy saving technologies are envelopment insulation, high efficiency lighting, high performance HAVC system and used active equipment system of solar collector and photovoltaic generation for additional savings.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.335-350
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• 2013

With the efforts to development of renewable energy technologies, and increasing awareness to environmental issues, the usage of wood pallets has been increasing every year since the introduction of wood pallet technology to the domestic market. until 2009, majority usage of pellet boiler was in the residential houses. In an effort to increase the distribution of wood pellet boiler to cultivation facilities with high usage of fuels, The Ministry of Agriculture and Forestry has launched a distribution project of wood pellet boiler for fuel usage as a part of the agricultural and fishery energy efficiency projects. Although only small number of farms with a heat-culturing facility have replaced from conventional boiler to pellet boiler. Although part of reason for low usage of pallet boiler is lack of understanding and information of it, the main reasons are high initial cost and uncertainty of its cost efficiency. Also, most people from agricultural industry don't realize it's significance in terms of environmental benefit due to lack of understanding in 'resource circulation' and 'adopting to climate change'. In this study, first, we did a cost-efficiency analysis of the farm which uses a diesel boiler to grow cucumber, tomato, paprika. Then we replaced the diesel boiler to a pallet boiler and measured its cost-efficiency again. By comparing the cost-efficiency of the diesel boiler with the pellet boiler, we analyzed the economic viability of pellet boiler. Then we analyzed viability of pallet boiler usage in terms of 'resource circulation' and 'adopting to climate change'. As a result of our analysis, we have found out that under the current system of government support, the energy usage varies depends of the types crops grown and the higher the energy use, the more cost efficient it is to use the pallet boiler. Also, it is economically viable to use the pallet boiler in terms of 'resource circulation' and 'adopting to climate change'.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.8
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• pp.3243-3256
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• 2020

Recent years have shown a great interest of public in buying and selling of crypto/digital currency. With hundreds of digital currencies in financial market, bitcoin remains the most widely used, adapted, and accepted currency around the world. However, the critics of bitcoin still consider it a threat to modern day power usage. This paper discusses the important pitfalls, pros, and cons related to bitcoin's energy consumption. The paper begins by highlighting the flexibilities cryptocurrency can bring to online money transfers compared to traditional 'fiat' architecture. Then, the focus of the paper entirely remains on listing various facts related to bitcoin's energy utilization including a brief description of several emerging approaches for energy optimization. This paper is concluded by revealing key current challenges associated to bitcoin's energy usage.