• Journal of People, Plants, and Environment
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• v.22 no.2
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• pp.219-229
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• 2019

This study was carried out to verify the accuracy of fitness tracking devices in monitoring heart rate and energy consumption and to contribute to the development of a forest exercise program that can recommend the intensity and amount of forest exercises based on personal health-related data and provide monitoring and feedback on forest exercises. Among several commercially available wearable devices, Fitbit was selected for the research, as it provides Open API and data collected by Fitbit can be utilized by third parties to develop programs. Fitbit provides users with various information collected during forest exercises including exercise time and distance, heart rate, energy consumption, as well as the altitude and slope of forests collected by GPS. However, in order to verify the usability of the heart rate and energy consumption data collected by Fitbit in forest, the accuracy of heart rate and energy consumption were verified by comparing the data collected by Fitbit and reference. In this study, 13 middle-aged women were participated, and it was found that the heart rate measured by Fitbit showed a very low error rate and high correlation with that measured by the reference. The energy consumption measured by Fitbit was not significantly different from that measured in the reference, but the error rate was slightly higher. However, there was high correlation between the results measured by Fibit and the reference, therefore, it can be concluded that Fitbit can be utilized in developing actual forest exercise programs.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.2
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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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.8
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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%.

• Journal of the Korean housing association
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• v.13 no.2
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• pp.73-78
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• 2002

Recently, the energy consumption has been sharply increased and the environmental pollution has been serious, resulted in increased use of fossil fuel. These facts are applied to most fields, and are especially important issues in the field of architecture. The energy consumption rate of building is about 30% of all energy consumption, and the rate of residential is about 20% of the rate of building and is increasing gradually. The purpose of this article is firstly to analyse an actual energy consumption rate of model building and compare it with alternative methods, which are applied passive system to, and secondly to suggest an optimal passive method for saving energy. The conclusion of this study is as follows; 1) As compared with the existing house on actual energy consumption rate, 6% in changing orientation to a south, 9% in using double low-e glazing and 23% in shading is decreased. 2) The change of insulation from 50 to 100mm did not show dramatical difference in energy consumption rate. 3) As changed indoor temperature at 2$0^{\circ}C$ in winter and 27$^{\circ}C$ in summer, the rate shows a reduction of 14% compared with the existing condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3950-3957
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• 2010

Wireless sensor network is composed of sensor node with limited sources, and to maintain and repair is vexatious once made up. Accordingly it is important matter to maximize the network lifetime by minimizing the energy consumption in wireless sensor network, and utilizing the limited sources efficiently. In this paper, I propose a technique arranging the cluster number with efficiency in clustering method to optimize the energy consumption. The energy usage needed for wireless transmission varies in distance(threshold). This technique reduces the energy consumption considering the threshold when arranging the cluster number. I verify that the clustering method organized through the valid processes outperform the LEACH(Low-Energy Adaptive Clustering Hierarchy) in total energy consumption.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1028-1036
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• 2006

Energy conservation is an important issue in wireless networks, especially for self-organized, low power, low data-rate impulse-radio ultra-wideband (IR-UWB) networks, where every node is a battery-driven device. To conserve energy, it is necessary to turn node into sleep state when no data exist. This paper addresses the energy consumption analysis of Direct-Sequence (DS) versus Time-Hopping (TH) multiple accesses and two kinds of sleeping protocols (slotted and unslotted) in PHY-MAC for Un networks. We introduce an analytical model for energy consumption or a node in both TH and DS multiple accesses and evaluate the energy consumption comparison between them and also the performance of the proposed sleeping protocols. Simulation results show that the energy consumption per packet of DS case is less than TH case and for slotted sleeping is less than that of unslotted one for bursty load case, but with respect to the load access delay unslotted one consumes less energy, that maximize node lifetime.

• Journal of the Korean Solar Energy Society
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• v.40 no.1
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• pp.15-24
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• 2020

Building energy consumption generally depends on living patterns of residents and outdoor air temperature changes. Although outdoor air temperature changes effect on building energy consumption, there is no calibration method for the comparison before and after Green Remodeling or BEMS installation etc., Big data of building energy consumption are collected and managed by 『National Integrated Management System of Building Energy』 in Korea, and they are utilized for the development of a calibration method for individual buildings as shown as the calibration method for small-area building stocks in the previous research. This study aims to develope a calibration method using big data of building energy consumption of individual buildings and outdoor air temperature changes, and to propose application of appropriate calibration methods for individual buildings or small-area building stocks according to the calibration purpose and conditions.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.857-862
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• 2008

Window is the most demanding design component in the building design. Recently, window area in the building surface has been increased significantly in the office building. As window area increased significantly, however, the thermal load has been increased significantly due to lack of thermal performance of the outside wall. In this paper, we discussed the energy consumption of the buildings according to window area ratio. Two types of building for energy consumption analysis were made by Designbuilder v.1.4 and Energyplus v.2.0. Window area ratio was five different types ($30%{\sim}70%$) in each building. As a result, the cooling energy consumption has been decreased as window area decreased in each building. Whereas the heating energy consumption has been increased window area decreased.

• Journal of the Korean Solar Energy Society
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• v.38 no.6
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• pp.15-26
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• 2018

It is difficult to check the exact building energy consumption reduction such as when green remodeling of buildings, because it is due to outdoor air temperature over the years. And in Korea although Big Data of building energy consumption is collected and managed through "The Information System of the Building Energy and Greenhouse Gases" it is underutilized because of non calibration of outdoor air temperature change. Therefore, this study aims to develope calibration method of building energy consumption by outdoor air temperature according to micro climates, and building use types. As a result of analysis, Regression equations of Building energy consumption and $HDD_m/CDD_m$ are derived and calibration method is developed by Regression coefficient.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.79-90
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• 2021

This study aims to investigate the relationship between urbanization, economic growth, energy consumption, and CO2 emissions in Indonesia. The data used in the study are time-series data for the period 1985-2017; the data utilized are sourced from World Development Indicators obtained on the World Bank database. The method uses a quantitative approach that applies the vector error correction model based on the Granger causality test. The empirical results reveal that, in the short run, there is evidence that urbanization and energy consumption can causes CO2 emissions, and they also prove that urbanization can cause energy consumption. Also, other findings prove the existence of long-run relationships flowing from energy consumption, economic growth, and CO2 emissions toward urbanization, as well as the existence of the relationship flowing from urbanization, economic growth, and CO2 emissions towards energy consumption. The results of testing the relationship between economic growth and CO2 emissions reveal that the environmental Kuznets curve hypothesis is proven in Indonesia. Thus, policies are needed to limit the impact of urbanization through high awareness-raising to maintain environmental quality and greater use of energy. Also, energy conservation policies are needed in all sectors, especially the electricity, industry, and transportation sectors.