• Title/Summary/Keyword: Useful energy

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Development of a Method of Pre-Feasibility Study for the Application of Co-Generation System in New Apartment (신설아파트 열병합발전 도입에 대한 예비 타당성 분석기법 개발)

  • Kee, Woo-Bong;Kim, Kwang-Ho
    • Journal of Industrial Technology
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    • v.27 no.A
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    • pp.185-193
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    • 2007
  • The object of this study is the development of a Method which is enable to review the preliminary feasibility for co-generation system in new apartment buildings. In Korea co-generation systems have been installed in most of large industrial plants and commercial buildings which consume a large quantity of electric and heat energy, for energy saving and cutting products cost, under positive governmental supports. However for apartment buildings which consume quite a large electric and heat energy, are still remained in conventional energy supply system, and are not popular to utilize useful co-generation system. One of the major reason for these is the lack of clear and easy justification tool. In this circumstance, this study can provide a tool to verify the feasibility of co-generation in apartment buildings with this handy tools for planners and designers beforehand.

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Losses Comparison and Analysis for Fault Modes of Grid-connected Photovoltaic System (계통연계형 태양광발전 시스템의 고장유형별 손실 비교분석)

  • So, Jung-Hun;Ko, Suk-Whan;Ju, Young-Chul
    • Journal of the Korean Solar Energy Society
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    • v.37 no.3
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    • pp.23-32
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    • 2017
  • This paper presents losses comparison and analysis results for different types of fault modes of grid-connected photovoltaic system generated for long-term operation. The approach of losses comparison and analysis by faults is to identify relationship between measured and estimated values of five loss factors which are quantified from irradiance to system output power. This paper presents the symptom results for faults such as snow, shading, sensor defect, blackout, soiling and so on from three years or more monitored data. These results will indicate that it is useful to develop fault detection and diagnosis tool to enhance capacity factor and save operation and maintenance cost of grid-connected photovoltaic system in the field.

Configuration and Economic Analysis of Cogeneration Systems using COGENMASTER model (COGENMASTER 모형을 이용한 열병합발전 시스템 구성 및 경제성 분석)

  • Park, J.J.;Jo, I.S.;Kim, C.S.;Kwun, Y.H.
    • Proceedings of the KIEE Conference
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    • 1994.11a
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    • pp.27-29
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    • 1994
  • Recently, the energy situation in Korea has been significantly changed. Rapid increase in electricity demand, tremendous financial need for new power plant construction, and environmental problem have led to search for more efficient energy production and energy conservation technologies. Due to the potential energy and cost savings to both electric utilities and industries, cogeneration will play an important role in the electric power and thermal energy supply in the future. In this study, we present the COGENMASTER computer model for optimal system configuration and economic analysis of cogeneration system. We also present several case studies with this module to analyze Korean cogeneration market. The result of this study will be useful to utility and industrial cogeneration planners for rapid analysis of cogeneration's value under a broad range of scenarios.

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Vehicle tire Noise/Vibration Characteristic Analysis using SEA(Statistical Energy Analysis) (SEA를 이용한 승용차 타이어의 소음/진동 특성 해석)

  • 김윤철;채장범;강기석;이상주;이승규
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.719-724
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    • 2001
  • The study on reducing vehicle noise and vibration has gained much attention to ensure the comfortability as well as the safety. These days. in this paper, we applied Statistical Energy Analysis(SEA) to characterize the tire assembly, which is useful analytical tool for mid- and high-frequency range. First, the SEA tire model was developed by dividing the tire and the wheel into several subsystems. The material properties were estimated experimentally. Finally. the SEA model was validated by comparing the estimated and the measured. In addition, we investigated the energy level and the energy transfering paths through the tire assembly in different frequency region.

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Energy Efficient and Multimedia Traffic Friendly MAC Protocol in Wireless Sensor Networks (무선 센서 네트워크에서 에너지 효율적이고 멀티미디어 트래픽에 적합한 MAC 프로토콜)

  • Kim, Seong Cheol;Kim, Hye Yun;Kim, Joong Jae
    • Journal of Korea Multimedia Society
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    • v.19 no.8
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    • pp.1460-1465
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    • 2016
  • In this paper, we propose an energy efficient and multimedia traffic friendly MAC protocol (EEMF-MAC) that controls sender's wakeup period based on the data packet's transmission urgency and the receiver's wakeup periods based on the received data packet traffic loads. The protocol is useful for applications such as object tracking, real time data gathering, in which priority-based packet transmission is required. The basic idea of EEMF-MAC is that it uses the priority concept with transmission urgency of sender's data packet to reduce the transmission delay of the urgent data and it also uses duty cycling technique in order to achieve energy efficiency. EEMF-MAC showed a better performance in energy efficiency and packet transmission delay compared to existing protocols, RI-MAC and EE-RI-MAC.

Optimal Gamma Irradiation Using Monte Carlo Simulations on Wooden Cultural Properties, Gimjeotgae (목재 유물 김젖개의 몬테카를로 방법을 이용한 감마선 조사)

  • Yoon, Minchul;Choi, Jong-il;Lee, Yun Jong;Lim, Kil-Sung;Lee, Ju-Woon
    • Journal of Radiation Industry
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    • v.6 no.1
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    • pp.95-100
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    • 2012
  • In this study, there has been investigated the simulation of irradiation dose using Monte Carlo methodology for the biological control of wooden cultural property. In the evaluation of fungal contamination on wooden cultural properties, Cladosporium tenuissimum, Aspergillus versicolor, Penicillium sp. were mainly identified from the Gimjeotgae. But these microorganisms were completely inactivated by 20 kGy gamma-rays. For dosimetry simulation of wooden cultural properties, Monte Carlo methodology with MCNP was used. The radiation absorbed dose distribution was predicted at 8.2~18.9 kGy. These results show that irradiation is effective for biologic control of wooden cultural properties and Monte Carlo methodology is useful for non-destructive conservation and preservation of wooden cultural properties.

Molecular Weight Control of Chitosan Using Gamma Ray and Electron Beam Irradiation

  • Kim, Hyun Bin;Lee, Young Joo;Oh, Seung Hwan;Kang, Phil Hyun;Jeun, Joon Pyo
    • Journal of Radiation Industry
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    • v.7 no.1
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    • pp.51-54
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    • 2013
  • Chitosan is a useful natural polymer material in many application fields such as biomaterials, water-treatment, agriculture, medication, and food science. However, the poor solubility limits its application. In this study, the effects of radiation on chitosan were investigated using gamma ray and electron beam irradiation. The chemical structure and molecular weight analysis show similar degradation effects of chitosan powder in both gamma ray and electron beam irradiation. However, the radiation irradiated chitosan in $H_2O$ has a lower molecular weight, since the hydroxyl radicals attack the glycosidic bonds. This effect is more clearly shown in the electron beam irradiation results.

Development of Pressurizer Level Control System using Centrifugal Charging Pump and Letdown Orifices for YGN 5&6

  • Jeong, Won-Sang;Shon, Suk-Whun;Seo, Ho-Taek;Seo, Jong-Tae;Lee, Sang-Keun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.484-490
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    • 1996
  • The Pressurizer Level Control System (PLCS) logic for YGN 5&6 was developed to incorporate the design changes on the Chemical and Volume Control System (CVCS). The YGN 5&6 CVCS uses the centrifugal charging pumps and letdown orifices replacing the positive displacement pumps and letdown control valves in the YGN 3&4 and UCN 3&4. The purpose of this study is to develop new PLCS as well as validate newly developed control logic and its implementation method in the simulation computer code. The analysis results show that the new PLCS has adequate ability to control the pressurizer level in response to the design bases events, and the simulation computer code is useful for YGN 5&6 NSSS design code.

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Neutron yield and energy spectrum of 13C(alpha,n)16O reaction in liquid scintillator of KamLAND: A Nedis-2m simulation

  • Vlaskin, Gennady N.;Bedenko, Sergey V.;Ghal-Eh, Nima;Vega-Carrillo, Hector R.
    • Nuclear Engineering and Technology
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    • v.53 no.12
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    • pp.4067-4071
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    • 2021
  • The 13C (α,n)16O reaction cross-section is important data for nuclear physics, astrophysical, and neutrino physics experiments, however, they exhibit uncertainties due to the discrepancies in the experimental data. In this study, using the Nedis-2m program code, the energy spectrum of α-induced neutrons in a thin carbon target was calculated and the corresponding reaction cross-section was refined in the alpha particle energy range of 5-8 MeV. The results were used to calculate the intensity and energy spectrum of background neutrons produced in the liquid scintillator of KamLAND. The results will be useful in a variety of astrophysical and neutrino experiments especially those based on LS or Gd-LS detectors.

A Research on Influencing Factors of New Energy Vehicle Purchase Intention Based on BRA Theory and Environmental Cognitive Theory (BRA 이론과 환경 인지 이론에 기초한 신에너지 자동차 구매 의도에 영향을 미치는 요인에 관한 연구)

  • Li, Wei-jia;Liu, Zi-Yang;Yang, Qiao
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.07a
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    • pp.693-696
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    • 2022
  • The purpose of this paper is to explore the factors affecting the purchase intention of new energy vehicles, utilizing the BRA and VAM models. Based on self-interest and altruism, a model for willingness to use new energy vehicles was developed. Through analysis with analytical tools such as SPSS and AMOS, we obtained the following conclusions: Perceived value, perceived entertainment, and environmental values all have a significant positive impact on the purchase intention of new energy vehicles; Perceived risk has a negative impact on purchase intention. By conducting this research, useful suggestions can be made for the formulation of enterprise strategies, and new directions and inspirations can be provided for enterprises.

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