• Journal of the Korean Solar Energy Society
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• v.29 no.4
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• pp.48-57
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• 2009

Energy demands for hotels in Korea are surveyed and statistically analyzed to develop calculation models for a simulation. Daily energy loads of 16 hotels located in Seoul, Busan, Daegu, Inchon, and Daejon are analyzed based on energy log sheets. Detailed hourly loads are field measured for 3 hotels that are carefully selected among the surveyed. One of the salient features for energy consumption by hotels is their weekly periodicity. Relatively large values of deviations are observed for both heat and electricity loads through the country. The mains factors are: location, hotel grade (luxuriousness) and insulation. Detailed quantitative information such are annual average, daily variation, and hourly patterns are provided.

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.58-64
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• 2016

The main engine of a vehicle is used an common rail diesel engine for improving the efficiency of the whole load area. However, the generator engines is still used mechanical fuel injection valve drive cams. In addition, most of generator engines is applied a part-load operation of less than 50%. Therefore, diesel engine of vehicle set at 100% load is necessary to readjust in order to perform efficient operation because of part-load operation. In this study, the objective is to report the results of the part-load fuel consumption improvement by injection timing readjust to identify the operational characteristics of a generator engine currently operated in the facilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6B
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• pp.316-324
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• 2007

In this paper we proposed an energy consumption model for IR-UWB wireless sensor networks. The model takes the advantages of PHY-MAC cross layer design, and we used slotted and un-slotted sleeping protocols to compare the energy consumption. We addressed different system design issues that are responsible to energy consumption and proposed an optimum model for the system design. We expect the slotted sleeping will consume less energy for bursty load than that of the un-slotted one. But if we consider latency, the un-slotted sleeping model performs better than the slotted sleeping case.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.33-40
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• 2011

In this study, it is quantitatively analyzed for thermal Characteristics of isolation-heat paint which has been supplied to a domestic market through experiments and simulations. In the case of experiment using the container box, it shows 8% decrease on cooling energy consumption in a summer season, but shows increase on heating energy consumption. As a result, the analysis has found increase of energy consumption. As a result of holding simulations with meteorological data of domestic major cities, it shows an increase of energy consumption in domestic condition, and it is hard to expect an energy saving from the isolation-heat paint unless greater air-conditioning load.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.1
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• pp.1-13
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• 2023

Many government in the world have conducted building energy performance certification program to reduce building energy consumption. In this study, a reference building and its HVAC system was modeled, and the energy load and consumption were estimated by the ECO2 program. The software is a simple building energy simulation program based on monthly calculated method. The building energy efficiency rating the the reference building was 1+ under baseline condition. The simulation results showed that the insulation performance slightly affected building energy load and consumption, but light density had a significant effect on them. The application of geothermal heat pumps gave improvement of building energy efficiency rating but it could not make it possible to get zero energy building(ZEB) certification. The ZEB 5 certification could be achieved by using photovoltaics, however getting better grade was difficult. The simulation results showed that the ZEB 4 certification, one grade higher than ZEB 5, could be attained by using more than one renewable energy source such as geothermal and solar energy in this study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1204-1227
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• 2020

The tradeoff between energy conservation and traffic balancing is a dilemma problem in Wireless Sensor Networks (WSNs). By analyzing the intrinsic relationship between cluster properties and long distance transmission energy consumption, we characterize three node sets of the cluster as a theoretical foundation to enhance high performance of WSNs, and propose optimal solutions by introducing rendezvous and Mobile Elements (MEs) to optimize energy consumption for prolonging the lifetime of WSNs. First, we exploit an approximate method based on the transmission distance from the different node to an ME to select suboptimal Rendezvous Point (RP) on the trajectory for ME to collect data. Then, we define data transmission routing sequence and model rendezvous planning for the cluster. In order to achieve optimization of energy consumption, we specifically apply the economic theory called Diminishing Marginal Utility Rule (DMUR) and create the utility function with regard to energy to develop an adaptive energy consumption optimization framework to achieve energy efficiency for data collection. At last, Rendezvous Transmission Algorithm (RTA) is proposed to better tradeoff between energy conservation and traffic balancing. Furthermore, via collaborations among multiple MEs, we design Two-Orbit Back-Propagation Algorithm (TOBPA) which concurrently handles load imbalance phenomenon to improve the efficiency of data collection. The simulation results show that our solutions can improve energy efficiency of the whole network and reduce the energy consumption of sensor nodes, which in turn prolong the lifetime of WSNs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.193-195
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• 2011

Nowadays, climatic environment change has become a major issue in the world. This causes major emissions of carbon dioxide industries steel industry, thermal power industry, cement industry is essential in the reduction of carbon dioxide, which is based on total carbon dioxide emissions account for most of the construction industry in an effort to minimize the environmental load is needed. accordingly, through case studies, It can be induce the selection to minimize environmental load by comparing the output of quantitative energy consumption and carbon dioxide emissions per constructional methods. As a result of this study, RC Structure was less environmental load than SC structure.

• Journal of Biosystems Engineering
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• v.37 no.6
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• pp.385-397
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• 2012

Purpose: Drying characteristics of sawdust was studied under batch mode using lab scale microwave dryer. The objective of this study was to investigate the effect of material load and microwave output power on drying characteristics of sawdust. Methods: Material load and microwave output power were varied from 23 to 186 g and 530 to 370 W respectively. Different kinetic models were tested to fit the drying rates of sawdust. Similarly, the activation energy was calculated by employing the Arrhenius equation. Results: The drying efficiency increased considerably, whereas the specific energy consumption significantly decreased with increase in material load and microwave output power. The cumulative energy efficiency increased by 9%, and the specific energy consumption decreased by 8% when the material load was increased from 23 to 186 g. The effective diffusivity increased with decrease in material load and increase in microwave output power. The previously published model gave the best fit for data points with $R^2$ and RMSE values of 0.999 and 0.01, respectively. Conclusions: The data obtained from this study could be used as a basis for modeling of large scale industrial microwave dryers for the pellet production.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.8-13
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• 2009

Feasibilities of the application of a micro gas turbine cogeneration system to a large size hospital building are studied by estimating energy demands and supplies. The energy demand for electricity is estimated by surveying and sorting the consumption records for various equipment and devices. The cooling heating, and hot water demands are further refined with TRNSYS and ESP-r to generate load profiles for the subsequent operation simulations. The operation of the suggested cogeneration system in conjunction with the load data is simulated for a time span of a year to predict energy consumption and gain profile. The simulation revealed that the thermal efficiency of the gas turbine is about 30% and it supplies 60% of the electricity required by the building. The recovered heat can meet 56% of total heating load and 67% of cooling, and the combined efficiency reaches up to 70%.

• Land and Housing Review
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• v.1 no.1
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• pp.27-34
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• 2010

The energy consumption of residential sectors is given a sizable portion in total energy consumption. So, improvement of building performance can be as a part of principal energy strategy. For this reason, an evaluation tool for estimation of energy consumption was developed and supportive policies were considered in this study. In particular, energy saving technology were examined to practice the green home project, among them 7 items were selected as a factor for estimating energy consumption. In addition, to the simulation study on energy consumption, heating load, hot water demand and electric consumption was also studied with actual measured value. Further more, several supportive policies were discussed to encourage green home project in Korea.