• Title/Summary/Keyword: surplus energy

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Development of an Energy Model of Rice Processing Complex(II) -Simulation Model Development and Analysis of Energy Requirement- (미곡종합처리장의 에너지 모델 개발(II) -시뮬레이션 모델 개발 및 소요 에너지 분석-)

  • 장홍희;장동일;김만수
    • Journal of Biosystems Engineering
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    • v.20 no.3
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    • pp.275-287
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    • 1995
  • The rice processing complex(RPC) consisted of the rice handling, drying, storage, and milling processes. It has been established at 83 locations domestically by April 1994, and 200 of RPC will be built more throughout the country. Therefore, this study has been performed to achieve two objectives as the followings : 1) Development of mathematical models which can assess the requirement of electricity, fuel, and labor for four model systems of rice processing complex. 2) Development of a computer simulation model which produce the improved designs of RPC by the evaluation results of energy requirements of four RPC models. The results from this study are summarized as follows : 1) Mathematical models were developed on the basis of result of mass balance analysis and required power of machines for each process. 2) A computer simulation model was developed, which can produce the improved designs of RPC by the evaluation results of energy requirements. The computer simulation model language was BORLAND $C^{++}$. 3) The results of simulation showed that total energy requirements were ranged from 75.94㎾h/t to 124.30㎾h/t. 4) From the results of computer analysis of energy requirement classified by drying type, it was found that energy requirement of the drying type A{paddy rice (PR) for storage-natural air drying(15%), PR for milling-heated air drying(16%)} were less than that of the drying type B{1 step-natural air drying(PR for storage : 18%, PR for milling : 20%), 2 step-heated air drying(PR for storage : 15%, PR for milling : 16%)}. 5) The energy efficient drying method is that all the incoming rough rice to RPC should be dried by national air drying systems. If it is more than the capacity of national air drying system, the amount of surplus rough rice is recommended to be dried by the heated air drying method.

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Energy-aware Reed-Solomon Scheme for Improving Data Reliability in Solar-powered Wireless Sensor Networks (태양 에너지 기반 무선 센서 네트워크의 데이터 신뢰성 향상을 위한 에너지 적응형 Reed-Solomon 기법)

  • Jung, Jongwug;Kang, Minjae;Noh, Dong Kun;Cho, Sang Hoon
    • KIISE Transactions on Computing Practices
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    • v.23 no.2
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    • pp.122-127
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    • 2017
  • The data link layer operates reliable internode communication in the OSI reference model. Generally, the forward error correction (FEC) method is used in the data link layer of the wireless sensor network (WSN) environment that has a high frequency of errors. However, the FEC method consumes a significant amount of energy due to its high error correction rate, which negatively affects the networks' lifespan. In contrast with battery-based technology, energy is regularly recharged in the solar-powered WSN to meet higher energy needs than required for basic operation of existing nodes. By efficiently utilizing this surplus energy, the proposed energy-aware FEC method can reduce the data loss rate with no decrement of the network lifetime. The method employs a trade-off relationship between the energy and data loss rate by adjusting the parity length in the FEC method to the energy state in each node. The performance of the proposed scheme was verified through a simulation.

Comparison of Hemodynamic Energy between Expanded Polytetrafluoroethylene and Dacron Artificial Vessels

  • Lim, Jaekwan;Won, Jong Yun;Ahn, Chi Bum;Kim, Jieon;Kim, Hee Jung;Jung, Jae Seung
    • Journal of Chest Surgery
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    • v.54 no.2
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    • pp.81-87
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    • 2021
  • Background: Artificial grafts such as polyethylene terephthalate (Dacron) and expanded polytetrafluoroethylene (ePTFE) are used for various cardiovascular surgical procedures. The compliance properties of prosthetic grafts could affect hemodynamic energy, which can be measured using the energy-equivalent pressure (EEP) and surplus hemodynamic energy (SHE). We investigated changes in the hemodynamic energy of prosthetic grafts. Methods: In a simulation test, the changes in EEP for these grafts were estimated using COMSOL MULTIPHYSICS. The Young modulus, Poisson ratio, and density were used to analyze the grafts' material properties, and pre- and post-graft EEP values were obtained by computing the product of the pressure and velocity. In an in vivo study, Dacron and ePTFE grafts were anastomosed in an end-to-side fashion on the descending thoracic aorta of swine. The pulsatile pump flow was fixed at 2 L/min. Real-time flow and pressure were measured at the distal part of each graft, while clamping the other graft and the descending thoracic aorta. EEP and SHE were calculated and compared. Results: In the simulation test, the mean arterial pressure decreased by 39% for all simulations. EEP decreased by 42% for both grafts, and by around 55% for the native blood vessels after grafting. The in vivo test showed no significant difference between both grafts in terms of EEP and SHE. Conclusion: The post-graft hemodynamic energy was not different between the Dacron and ePTFE grafts. Artificial grafts are less compliant than native blood vessels; however, they can deliver pulsatile blood flow and hemodynamic energy without any significant energy loss.

A Study on Development of Small Scale Electric Power Management System for Smart Grid (스마트 그리드를 위한 소규모 전력에너지 관리 시스템 개발에 관한 연구)

  • Lee, Chang-Soo;Oh, Hea-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.6
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    • pp.2826-2832
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    • 2012
  • A smart grid is an electric-power grid that employs a new information technology.This technology makes it possible to exchange real-time energy information between suppliers and consumers, finally resulting in high energy efficiency. The energy management system in smart grid provides up to date information on electricity consumption as well as dynamic electricity price to consumers of smart grid system. However, the existing energy management systems only focus on pricing system, for example, real-time electricity prices. In this paper, we try to improve the existing energy management system and propose the energy management system that mainly focuses on the efficiency of electricity consumption. In the proposed management system, PMU(Phasor Measurement Units) installed in switchboards gathers electricity data in a real time. We also propose to use data mining method, which is applied to analyzed electricity data for improving energy efficiency. Also, the proposed energy management system is designed to efficiently control the electricity between PMU and management system in case of a shortage of electricity or surplus electricity.

Economic Valuation of the Municipal Water: Residential and Non-residential Uses (전국 생활용수의 경제적 가치 평가: 가정용수 대 비가정용수)

  • Ku, Se-Ju;Yoo, Seung-Hoon
    • Journal of Korea Water Resources Association
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    • v.43 no.11
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    • pp.957-965
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    • 2010
  • The municipal water is directly related to the people's quality of life. To examine and implement reasonable water policies including management of the water demand and economically sound investment decisions, it is essential to estimate the conceptually correct and empirically valid economic value of water. This study attempts to estimate the consumer surplus and economic value of municipal water which is supplied to 16 cities in Korea using demand curve approach. The results indicate that the consumer surplus and economic value of municipal water in 2009 are estimated as KRW 1,180.7 per $m^3$ and KRW 1,812.8 per $m^3$, respectively. The economic values of municipal water in 16 cities range from KRW 1,082.7 per $m^3$ to KRW 3,268.6 per $m^3$. Moreover, the economic value of non-residential water is higher than that of residential water in all cities, and the economic value of water is higher than the present price of water. This study is expected to provide policy-makers with useful information to assess a policy and to evaluate the price of water.

SO2 Emission Permits Tradable under Exchange Rates : U.S. Case (다수 거래비율하에서의 SO2 배출권 거래 : 미국 사례)

  • Hlasny, Vladimir
    • Environmental and Resource Economics Review
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    • v.20 no.4
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    • pp.689-733
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    • 2011
  • This study evaluates a novel scheme to trade sulfur dioxide emission permits subject to non-uniform rates. These rates are based on generators' marginal costs of compliance with environmental policy in a hypothesized least social-cost solution. This scheme is compared against the existing trading program used by the U.S. Environmental Protection Agency, featuring permits tradable one for one. Both policies are modeled to yield identical aggregate emissions. A numerical partial-equilibrium model of the U.S. energy industry is used to infer sulfur dioxide concentrations and health damages, as well as producer and consumer surplus, under the two policies. Regional pollution levels are found to vary across the two policies significantly. The system of exchange rates is estimated to outperform the uniform-trading scheme by $2.2 billion in industry profits and $2.1 billion in health damages, but to reduce consumer surplus by $6.7 billion. Paradoxically, exchange rates are thus estimated to lower total welfare by $2.5 billion. This is due to conceptual mechanism-design problems, as well as empirical issues.

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A Study on the Aesthetic Identity of Modern Eroticism Fashion from the Perspective of Jacques Lacan's Unconscious Theory -Focusing on Jouissance & Gaze Theory- (자크 라캉 무의식이론의 관점에서 본 현대 에로티시즘 패션의 미적 정체성 연구 -주이상스와 응시론을 중심으로-)

  • Jungwon Yang;Misuk Lee
    • Journal of Fashion Business
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    • v.27 no.2
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    • pp.124-139
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    • 2023
  • The purpose of this study is to determine the aesthetic identity of modern eroticism fashion in which the energy of desire is maximized through the 'jouissance' and 'gaze' of the unconscious theory of Jacques Lacan. The research method derived aesthetic identity after examining jouissance and gaze deeply related to eroticism in Lacan's theory of the unconscious by analyzing data of domestic and foreign monographs and prior research. Case analysis was limited to 2000 S/S to 2022 F/W. Based on prior research, it was analyzed mainly on clothing with eroticism characteristics of 'exposure, close contact, see-through, the conversion of underclothes into outer garments'. Results of the study are as follows. First, eroticism, which can be linked to Lacan's type of 'jouissance' with multiple meanings as the generating point of eroticism, has manifested itself in voyeuristic eroticism, fatale eroticism, masochistic eroticism, surplus eroticism, and sacred eroticism. Second, as eyes of unconscious desire, visual expression characteristics of 'gaze' appeared as anamorphosis, trompe l'oeil, and dépaysement. The identity of eroticism derived from Lacan's jouissance and the perspective of the desire gaze was divided into voyeuristic desire to gaze, fatal desire to gaze, masochistic desire to gaze, surplus desire to gaze, and sacred desire to gaze. Results of this study will expand theoretical horizons of eroticist fashion with a new interpretation of eroticism by combining Lacan's desire as a repressed and alienated subject within the human unconscious with the art that expands it.

Measurement and Analysis of Regenerative Energy in DC 1500V Electric Traction Substation (직류 1500V 전철변전소의 회생전력량 측정 및 분석)

  • Bae, Chang-Han;Jang, Dong-Uk;Kim, Ju-Rak;Han, Moon-Seub;Kim, Yong-Ki
    • Journal of the Korean Society for Railway
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    • v.10 no.6
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    • pp.717-722
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    • 2007
  • Most of DC 1500V electric railway substations have adopted diode rectifiers to supply stable DC power. However, the diode rectifiers operate in the first quadrant of the voltage-current plane and thus need regenerative inverters which transfer the surplus regenerative power caused by regenerative braking of electric train sets into the grid. In order to select the proper capacity and installation position of regenerative inverter, it needs to investigate the consumed and regenerative energy of the electric traction substations in advance. This paper presents an analysis of regenerative energy in two substations operating in Seoul Seolleung and Kwangju Yangdong substations. DC line voltage and feeder currents are measured for a day to calculate consumed and regenerative power far four feeders. We calculated an amount of regenerative energy consumed in other feeders and estimated the cost reduction in energy consumption due to the reuse of regenerative energy

The Efficiency and General Equilibrium Effect by the Emission Trading Structure under the Climate Change Convention (기후변화협약 하의 배출권 거래 대상에 따른 일반균형효과와 효율성 비교)

  • Hur, Gahyeong;Cho, GyeongLyeob
    • Environmental and Resource Economics Review
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    • v.15 no.2
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    • pp.201-245
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    • 2006
  • We applied general equilibrium model to analysis the economic impact of international emission trading by sector and the efficiency of the Convention to study whether Climate Change Convention satisfy the efficiency. We divided the world as 4 groups : USA, OECD members w/o USA (OEC), Former Soviet Union (FSU) and Developing countries (DEV). Compared to no trading, global trading would accomplish the same environmental effect with less cost as much as 97.8 billion$, which is the surplus of trading. However, half of it is taken by USA and 20% by OEC. FSU and DEV have only 18% and 10%. This result suggest the two things. First, the emission trading is effective as far as the participation of developing countries are guaranteed. If they do not take part in the coalition and emit the leakage, it may threaten the stability of the international trading coalition. Second, we found the logical ground of the side payment for developing countries. The permit buying countries take more share of the surplus under the emission trading, while the energy sector of developing countries shrinks to sell permits, which may adversely affect to economic growth of the countries. Therefore, the Annex-I countries need to provide side payment to lead the participation of the developing countries.

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The Optimum Control Study for Improving Efficiency of the small hydropower generation in water pipe (수도관로 소수력발전 운영효율 향상을 위한 최적제어 방안)

  • Hong, Jeong-Jo;Rim, Dong-Heui;Kim, Soo-Sang
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.126-129
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    • 2008
  • Using a surplus head in presented water supply pipes, we have studied to improve the operating efficiency of small hydro generator, which was chosen for a test model with Sung-Nam and Bo-Ryong small hydro power plant. With regard to power control and countermeasure of water hammer impact, Finally we have represented the optimal control method through the synthetical analysis of existing system symptoms, operation efficiency, the effect of water hammer impact and system configuration.

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