• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.5 no.2
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• pp.13-19
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• 2009

This study describes energy and exergy analysis of the Maeeum-Ri Geothermal District Heating System(MGDHS) of Ganghwa Island, Incheon, Korea. Design data are used to assess the performance of the geothermal district heating system. Geothermal resources of MGDHS are found to be low quality with specific exergy index of 0.029. Exergy losses occur in the pumps and heat exchangers as well as in the geothermal Quid and direct discharge. As a result, the total exergy losses accounts for 5.2% in pumps, 47% in the discharge, and 3.3% in heat exchanger based on the total exergy input to the entire MGDHS. The overall energy and exergy efficiencies of the system are found to be 28.8% and 44.5%, respectively.

• Journal of Semiconductor Engineering
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• v.1 no.1
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• pp.31-37
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• 2020

We present an approximate DRAM architecture for energy-efficient deep learning. Our key premise is that by bounding memory errors to non-critical information, we can significantly reduce DRAM refresh energy without compromising recognition accuracy of deep neural networks. To validate the key premise, we make extensive Monte-Carlo simulations for several well-known convolutional neural networks such as LeNet, ConvNet and AlexNet with the input of MINIST, CIFAR-10, and ImageNet, respectively. We assume that the highest-order 8-bits (in single precision) and 4-bits (in half precision) are protected from retention errors under the proposed architecture and then, randomly inject bit-errors to unprotected bits with various bit-error-rates. Here, recognition accuracies of the above convolutional neural networks are successfully maintained up to the 10^-5-order bit-error-rate. We simulate DRAM energy during inference of the above convolutional neural networks, where the proposed architecture shows the possibility of considerable energy saving up to 10 ~ 37.5% of total DRAM energy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3823-3840
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• 2017

This paper analyzes the nodes deployment optimization problem in energy constrained wireless sensor networks, which multi-hop cooperative beamforming (CB) based cooperative-multi-input-single-output (CMISO) transmission is adopted to reduce the energy consumption. Firstly, we establish the energy consumption models for multi-hop SISO, multi-hop DSTBC based CMISO, multi-hop CB based CMISO transmissions under random nodes deployment. Then, we minimize the energy consumption by searching the optimal nodes deployment for the three transmissions. Furthermore, numerical results present the optimal nodes deployment parameters for the three transmissions. Energy consumption of the three transmissions are compared under optimal nodes deployment, which shows that CB based CMISO transmission consumes less energy than SISO and DSTBC based CMISO transmissions. Meanwhile, under optimal nodes deployment, the superiorities of CB based CMISO transmission over SISO and DSTBC based CMISO transmissions can be more obvious when path-loss-factor becomes low.

• Structural Engineering and Mechanics
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• v.3 no.3
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• pp.255-272
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• 1995

The paper considers aspects of the energy dissipation response of selected realistic forms of torsionally balanced and torsionally unbalanced building systems, responding to an ensemble of strong-motion earthquake records. Focus is placed on the proportion of the input seismic energy which is dissipated hysteretically, and the distribution of this energy amongst the various lateral load-resisting structural elements. Systems considered comprise those in which torsional effects are discounted in the design, and systems designed for torsion by typical code-defined procedures as incorporated in the New Zealand seismic standard. It is concluded that torsional response has a fundamentally significant influence on the energy dissipation demand of the critical edge elements, and that therefore the allocation of appropriate levels of yielding strength to these elements is a paramount design consideration. Finally, it is suggested that energy-based response parameters be developed in order to assist evaluations of the effectiveness of code torsional provisions in controlling damage to key structural elements in severe earthquakes.

• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.62-62
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• 2000

No Abstract, See Full Text

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.04a
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• pp.340-341
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• 1999

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.309-311
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• 2013

• 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.

• Environmental and Resource Economics Review
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• v.22 no.3
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• pp.547-580
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• 2013

As energy conservation can be realized through changes in the composition of goods and services consumed, there is a need to assess indirect and total household energy consumption. The Korean household sector was responsible for more than 55% of Korea's total energy consumption in the 1995 to 2010 period. More than 69% of household energy consumption was indirect. Thus, not only direct but also indirect household energy consumption should be the target of energy conservation. Electricity consumption became in 2009 the main source of household energy consumption in Korea. Households consume more and more electricity intensive goods and services, a sign of increasing living standards. Decrease in energy intensities of products consumed by Korean households contributed greatly to reduce the increase in the total household energy consumption. However, switching took place towards more energy intensive products, thus the structure effect was negative. It is necessary to direct consumption and production towards much less energy intensive goods and services as to reduce energy consumption or its growth rate. The Korean government should readjust low energy and electricity prices to cost-reflective prices levels as these low prices are one of the main reasons for the consumption of more energy intensive products. This study differentiates prices of oil products and electricity between households and industries, as to allow more accurate estimation.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.137-145
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• 2011

BIM Data exchange using standard format can provide a user friendly and practical way of integrating the BIM tools in the life cycle of a building on the currently construction industry which is participated various stakeholder. It used IFC format to exchange the BIM data from Design software to energy analysis software. However, since we can not use the material name data in the library of an energy analysis directly, it is necessary to input the material property data for building energy analysis. In this paper, to matching the material named of name of DOE-2 default library, rhe extracted material names from BIM file are inferred by the ontology With this we can make the reliable input data of the engine by development a standard data and also increase the efficient of building energy analysis process. The methodology can enable to provide a direction of BIM-based information management system as a conceptual study of using ontology in the construction industry.