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Fuzzy Logic based Admission Control for On-grid Energy Saving in Hybrid Energy Powered Cellular Networks

  • Wang, Heng;Tang, Chaowei;Zhao, Zhenzhen;Tang, Hui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.10
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    • pp.4724-4747
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    • 2016
  • To efficiently reduce on-grid energy consumption, the admission control algorithm in the hybrid energy powered cellular network (HybE-Net) with base stations (BSs) powered by on-grid energy and solar energy is studied. In HybE-Net, the fluctuation of solar energy harvesting and energy consumption may result in the imbalance of solar energy utilization among BSs, i.e., some BSs may be surplus in solar energy, while others may maintain operation with on-grid energy supply. Obviously, it makes solar energy not completely useable, and on-grid energy cannot be reduced at capacity. Thus, how to control user admission to improve solar energy utilization and to reduce on-grid energy consumption is a great challenge. Motivated by this, we first model the energy flow behavior by using stochastic queue model, and dynamic energy characteristics are analyzed mathematically. Then, fuzzy logic based admission control algorithm is proposed, which comprehensively considers admission judgment parameters, e.g., transmission rate, bandwidth, energy state of BSs. Moreover, the index of solar energy utilization balancing is proposed to improve the balance of energy utilization among different BSs in the proposed algorithm. Finally, simulation results demonstrate that the proposed algorithm performs excellently in improving solar energy utilization and reducing on-grid energy consumption of the HybE-Net.

Impact Energy Absorption Mechanism of Largely Deformable Composites with Different Reinforcing Structures

  • Kang, Tae-Jin;Kim, Cheol
    • Fibers and Polymers
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    • v.1 no.1
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    • pp.45-54
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    • 2000
  • Impact behaviors of the large deformable composites of Kevlar fiber reinforced composites of different preform structures have been investigated. An analytic tool was developed to characterize the impact behavior of the Kevlar composites. The image analysis technique, and deply technique were employed to develop energy balance equation under impact loading. An energy method was employed to establish the impact energy absorption mechanism of Kevlar multiaxial warp knitted composites. The total impact energy was classified into four categories including delamination energy, membrane energy, bending energy and rebounding energy under low velocity impact. Membrane and bending energy were calculated from the image analysis of the deformed shape of impacted specimen and delamination energy was calculated using the deplying technique. Also, the impact behavior of Kevlar composites under high velocity impact of full penetration of the composite specimen was studied. The energy absorption mechanisms under high velocity impact were modelled and the absorbed energy was classified into global deformation energy, shear-out energy, deformation energy and fiber breakage energy. The total energy obtained from the model corresponded reasonably well with the experimental results.

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Wind Energy and Energy Policy in Germany (독일의 풍력 에너지 보급 현황과 지원 정책)

  • Lee, Seungmin;Lee, Soogab
    • 한국신재생에너지학회:학술대회논문집
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    • pp.134.1-134.1
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    • 2011
  • As eco-friendly energy is in the spotlight, lots of countries are out to develop and disseminate renewable energy. However, Korea still remains in relative newcomer position for renewable energy. To overcome the present condition, it is necessary to carry out a study of establishment of renewable energy policy that is appropriate the present situation of Korea from examples of advanced countries. Among several renewable energies, wind energy is known to be the most reliable energy. Germany that has increased the share of wind energy in total energy supply is a representative leading country for wind energy. Therefore wind energy policy in Germany will be a role model for that in Korea. In this study, as a research of portfolio for wind energy policy of advanced countries, a wide survey for current status of wind energy and energy policy in Germany is carried out.

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Development of Energy-FMEA for Energy Review of ISO 50001 Energy Management System

  • Song, Kyung-Il;Jang, Joong-Soon
    • Journal of Applied Reliability
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    • v.14 no.2
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    • pp.137-146
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    • 2014
  • This paper is to develop Energy-FMEA for Energy Review of ISO 50001 Energy Management System. Energy Review is the core requirement of ISO 50001. This study develop Energy-FMEA and suggest Energy Review Inventory and Assessment Criteria for performing Energy-FMEA. Also, it shows case study to verify whether to proper.

A Study on the Optimization of New Renewable Energy Systems in Public-Purpose Facilities (공공용 업무시설의 신재생에너지시스템 최적화 연구)

  • Lee, Yong-Ho;Seo, Sang-Hyun;Cho, Young-Hum;Hwang, Jung-Ha
    • Journal of the Korean Solar Energy Society
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    • v.33 no.5
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    • pp.95-104
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    • 2013
  • This study set out to devise an optimized system to take into account life cycle cost(LCC) and ton of carbon dioxide($TCO_2$) by applying the weighted coefficient method(WCM) to "public-purpose" facility buildings according to the mandatory 5% and 11% of new renewable energy in total construction costs and anticipated energy consumption, respectively, based on the changes of the public obligation system. (1) System installation capacity is applied within the same new renewable energy facility investment according to the mandatory 5% of new renewable energy in total construction costs. Both LCC and $TCO_2$ recorded in the descending order of geothermal, solar, and photovoltaic energy. The geothermal energy systems tended to exhibit an excellent performance with the increasing installation capacity percentage. (2) Optimal systems include the geothermal energy(100%) system in the category of single systems, the solar energy(12%)+geothermal energy(88%) system in the category of 2-combined systems, and the photovoltaic energy(12%)+solar energy(12%)+geothermal energy(76%) system and the photovoltaic energy(12%)+solar energy(25%)+geothermal energy(63%) system in the category of 3-combined systems. (3) LCC was the highest in the descending order of photovoltaic, geothermal and solar energy due to the influences of each energy source's correction coefficient according to the mandatory 11% of new renewable energy in anticipated energy consumption. The greater installation capacity percentage photovoltaic energy had, the more excellent tendency was observed. $TCO_2$ recorded in the descending order of geothermal, photovoltaic and solar energy with the decreasing installation capacity of photovoltaic energy. The greater installation capacity percentage a geothermal energy system had, the more excellent tendency it demonstrated. (4) Optimal systems include the geothermal energy(100%) system in the category of single systems, the photovoltaic energy(62%)+geothermal energy(38%) system in the category of 2-combined systems, and the photovoltaic energy(50%)+solar energy(12%)+geothermal energy(38%) system and the photovoltaic energy(12%)+solar energy(12%)+geothermal energy(76%) system in the category of 3-combined systems.

Design and Energy Performance Evaluation of Plus Energy House (플러스에너지하우스 설계 및 에너지 성능 평가)

  • Kim, Min-Hwi;Lim, Hee-Won;Shin, U-Cheul;Kim, Hyo-Jung;Kim, Hyun-Ki;Kim, Jong-Kyu
    • Journal of the Korean Solar Energy Society
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    • v.38 no.2
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    • pp.55-66
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    • 2018
  • South Korea aims to shift the 20 percent of electricity supplement from the fossil fuel including the nuclear to renewable energy systems by 2030. In order to realize this agenda in the buildings, the plus energy house is necessary to increase the renewable energy supplement beyond the zero energy house. This paper suggested KePSH (KIER Energy-Plus Solar House) and energy performance of house and renewable energy systems was investigated. The KePSH has the target of generating 40% surplus energy than the conventional house energy consumption. The plus energy house is the house that generates surplus energy from the renewable energy sources than that consumes. In order to minimize the cooling and heating load of the house, the shape design and passive parameters design were conducted. Based on the experimental data of the plug load in the typical house, the total energy consumption of the house was estimated. This paper also suggested renewable energy sources integrated HVAC system using air-source heat pump system. Two cases of renewable energy system integration methods were suggested, and energy performance of the cases was investigated using TRNSYS 17 program. The results showed that the BIPV (building integrated photovoltaic) system (i.e., CASE 1) and BIPV and BIST system (i.e., CASE 2) shows 42% and 29% of plus energy rate, respectivey. Also, CASE 1 can generate 59% more surplus energy compared with the CASE 2 under the same installation area.

An Suggestion of Improvement Plan and Analysis of Comparison about the Energy Performance Evaluation Tools for Application of the Technical Package in Zero Energy Building (제로에너지빌딩의 기술 패키지 적용을 위한 에너지성능 평가 도구 비교분석 및 개선방안 제안)

  • Cho, Soo;Han, Seol-Yee;Sung, Uk-Joo;Kim, Seok-Hyun
    • 한국건축친환경설비학회 논문집
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    • v.11 no.4
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    • pp.319-330
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    • 2017
  • The research of energy saving in building was studied many case of studies. The zero energy building contained a two concept like a minimum energy consumption and renewable energy facility installation for energy suppling. It means what the envelope of Zero Energy building has high performance of thermal. And the facility of building use independent heating and cooling energy consumption without outer source too. For accomplish the zero energy building, many technology were developed and applied at new building. In case of applying technology, the critical technology is enough for the zero energy building but the joint technology for zero energy building is not enough. Also the supply of the economical technology is difficult. To solving these difficult, the energy performance evaluation tool is used by many researchers in phase of the building design. These tool have a problem about reproducibility by the different input data. That was inputted by each simulator and they divided to level about expertise and situation. So they need to getting an specific information of building and advanced training of simulation. But for accomplish the zero energy building, these tool must be have modified to analysis of the building energy consumption suitably. Absolutely these tool need to update for the precision of analysis results. Additionally the zero energy building design contain a new technology for energy saving through the tool's extendability. In this study, authors was proposed the technical package and the case of simulation tool was compared for improvement suggestion. And this study was based actual certification and analysis tools like a ECO2. By these result, the authors was proposed two the improvement suggestion 'User friendly Interface' and 'Analysis reliability'.

Energy-based design base shear for RC frames considering global failure mechanism and reduced hysteretic behavior

  • Merter, Onur;Ucar, Taner
    • Structural Engineering and Mechanics
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    • v.63 no.1
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    • pp.23-35
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    • 2017
  • A nonlinear static procedure considering work-energy principle and global failure mechanism to estimate base shears of reinforced concrete (RC) frame-type structures is presented. The relative energy equation comprising of elastic vibrational energy, plastic strain energy and seismic input energy is obtained. The input energy is modified with a factor depending on damping ratio and ductility, and the energy that contributes to damage is obtained. The plastic energy is decreased with a factor to consider the reduced hysteretic behavior of RC members. Given the pre-selected failure mechanism, the modified energy balance equality is written using various approximations for modification factors of input energy and plastic energy in scientific literature. External work done by the design lateral forces distributed to story levels in accordance with Turkish Seismic Design Code is calculated considering the target plastic drift. Equating the plastic energy obtained from energy balance to external work done by the equivalent inertia forces considering, a total of 16 energy-based base shears for each frame are derived considering different combinations of modification factors. Ductility related parameters of modification factors are determined from pushover analysis. Relative input energy of multi degree of freedom (MDOF) system is approximated by using the modal-energy-decomposition approach. Energy-based design base shears are compared with those obtained from nonlinear time history (NLTH) analysis using recorded accelerograms. It is found that some of the energy-based base shears are in reasonable agreement with the mean base shear obtained from NLTH analysis.

A Study on the Appropriate Role of Solar Energy Considering Unstability of Depletable Energy Market (에너지 문제와 태양에너지의 역할)

  • Choi, Ki-Ryun
    • Solar Energy
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    • v.12 no.2
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    • pp.79-86
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    • 1992
  • To assure the appropriate role of solar energy in the future energy mix scenarios, considering the inevitable volatile and unstable energy market, it is urgent to introduce the "Soft Energy Path" concept. In Korean energy situation, the "Soft Energy Path" concept of solar energy has to be assured by the optimum technology mix of appropriate scale and quality for their individual tasks, especially in the industrial sector. So, the solar society is requested to establish an conceptional innovation regarding the merits of soft energy path and of ultimate potential of solar energy.

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A Study on Energy Storage System for Low Carbon, Green Growth of Electric Railway System (전기철도시스템의 저탄소 녹색성장을 위한 에너지저장시스템에 관한 연구)

  • Lee, Han-Min;Kim, Gil-Dong
    • Proceedings of the KIEE Conference
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    • pp.1161_1162
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    • 2009
  • The recent environmental protection trend requires more strict energy saving, therefore every transportation system should reduce energy consumption to the minimum value. High-efficiency operation system, energy saving and $CO_2$ emissions shall be addressed as important issue in railway system. These issues are the most essential factors of railway, compared to major public transportation system. Recently, saving energy in the electric railway system has been studied. For such new energy saving, the energy storage system is considered for saving energy. Energy saving is possible by efficient use of regenerated energy. Regenerated energy is recycled amongst vehicles by mean of charge and discharge corresponding to powering and braking of electric vehicle operations. This energy saving contributes to cut $CO_2$ to reduce greenhouse gas emissions. Recycling regenerated energy demonstrate significant effect on peak cut of consumption energy in railway substation. Absorption of excess energy avoids regeneration failure due to high traction voltage. Therefore, the energy storage system is needed to be adopted to use regeneration energy when the vehicle is braking.

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