• Title/Summary/Keyword: energy balance analysis

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Development of Energy Balance Analysis Program for LEO Satellite Design (저궤도 인공위성 설계를 위한 에너지 균형 분석 프로그램 개발)

  • Lee, Sang-Kon;Ra, Sung-Woong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.9
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    • pp.850-857
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    • 2007
  • The design and analysis of satellite electrical power subsystem is an important driver for the mass, size, and capability of the satellite. In particular, satellite energy balance analysis is critical in determining the capabilities and limitations of the power subsystem and the success of satellite operations. This paper introduces a new energy balance analysis program for LEO satellite development and shows an example of test results using other LEO satellite design data. The test results show that the proposed energy balance program can be used the optimal sizing of satellite electrical power subsystem and the analytical prediction of the on-orbit energy balance during satellite mission operations.

Nutritional Status and Requirements of Protein and Energy in Female Korean College Students Maintaining Their Usual and Activity(2) : Nitrogen Intake and Balance (자유로운 식이와 활동을 유지하는 한국 여대생의 에너지와 단백질대사에 대한 연구(2) : 질소섭취와 평형)

  • 김주연
    • Journal of Nutrition and Health
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    • v.28 no.4
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    • pp.259-267
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    • 1995
  • A study was conducted to investigate nitrogen balance and to estimate daily nitrogen requirement in 43 Korean female college students students maintaining their usual diet and activity levels. Nitrogen intake and excretion were measured in two separate peroids about one month apart, each period lasting for 3 days. Nitrogen intake was assessed by duplicate portion analysis of diet, and N excretion in faces and urine were measured during the study period. Mean daily nitrogen intake level was 129.3mg/kg B.W and the apparent digestibility of nitrogen was 76%. Mean daily urinary nitrogen excretion was 113.5mg/kg BW. 895 of total nitrogen intake. Mean daily nitrogen balance of subjects was -14.5mg/kg BW. Mean daily requirements of nitrogen for 0 balance, calculated by regression analysis of N balance and energy-adjusted N intake. were 1) 197.mg/kg B.W with the present energy intake level of the study subjects. 2) 157mg/kg B.W when energy intake is sufficient to maintain energy balance, and 30 130mg/kg B.W. when energy intake is Korean RDA level for moderate activity. When energy intake level is sufficient to meet their requirement, daily protein requirement for 0 balance is about 1.0g/kg B.W. The results of this study indicate that nitrogen intake level of young female college students is not sufficient to meet their requirements, and they should increase protein intake together with increase in energy intake.

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Effect Analysis on Energy Efficiency Improvement for Establishing Energy Balance Flow (Energy Balance Flow 구축에 의한 에너지효율향상 효과분석)

  • Kim, Yong-Ha;Jo, Hyun-Mi;Sin, Hyung-Chul;Kim, Hyung-Jung;Woo, Sung-Min;Kim, Young-Gil
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.679-680
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    • 2011
  • This paper is developed to Energy Balance Flow show the flow of total energy resource be used nationally. The Energy Balance Flow is applicable of demand management factor through the analysis of foreign energy model of supply and demand and energy statistic data in the country. This study is based on and developed to Energy system management model is able to appraisal efficient of energy cost cutting, CO2 emission reduction and Energy saving at the national level calculated effect reached amount of primary energy to change of energy flow followed application of demand side management factor is able to appraisal quantitatively at the total energy to model of demand and supply.

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Nutritional Status and Requirements of Protein and Energy in Female Korean College Students Maintaining Their Usual Diet and Activity(1) : Energy Intake and Balance (자유로운 식이와 활동을 유지하는 한국 여대생의 에너지와 단백질 대사에 대한 연구(1) : 에너지 섭취와 평형)

  • 김주연
    • Journal of Nutrition and Health
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    • v.27 no.4
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    • pp.336-346
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    • 1994
  • balance and to estimate daily energy requirement in 43 Korean female college students maintaining their usual diet and activity level. Energy intake and expenditure were measured in two separate periods about one month apart, each period lasting for 3 days. All the subjects participated in both periods. Energy intake was assessed by two methods ; weighed diet record and duplicate portion analysis of diet minus fecal and urinary excretion. Mean daily energy intake level calculated from diet records was 28.5 kcal/kgB.W(1, 476 kcal/day), and similar to the level of 27.8 kcal/kgB.W(1, 438 kcal/days) obtained from the chemical analysis of duplicate portions. Mean daily energy expenditure, calculated from activity records of each subject, was 34.6 kcal/kgB.W, or 1.39 times BMR, which corresponds to light activity level. Mean daily energy balance of subjects was -5.9 kcal/kgB.W. Mean daily requirement of energy, calculated from the activity records of the subjects, was 34.6 kcal/kgB.W, similar to the level of the Korean RDA for light activity level. The results of this study indicate that 1) the activity level of the study subjects corresponds to the sedentary level ; 2) present Korean RDA for energy for light activity is adequate for the subjects ; and 3) the subjects should increase their energy intake since they are largely in negative energy balance.

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A study on Development of Korean - Energy System Management Model for Effect Analysis of Integrated Demand Management (통합수요관리 효과분석을 위한 한국형 Energy System Management 모형 개발에 관한 연구)

  • Kim, Yong-Ha;Jo, Hyun-Mi;Kim, Ui-Gyeong;Yoo, Jeong-Hui;Kim, Dong-Gun;Woo, Sung-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.6
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    • pp.1103-1111
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    • 2011
  • This paper is developed to Energy Balance Flow show the flow of total energy resource be used nationally. The Energy Balance Flow is applicable of demand management factor through the analysis of foreign energy model of supply and demand and energy statistic data in the country. This study is based on and developed to Energy system management model is able to appraisal efficient of energy cost cutting, CO2 emission reduction and Energy saving at the national level calculated effect reached amount of primary energy to change of energy flow followed application of demand side management factor is able to appraisal quantitatively at the total energy to model of demand and supply.

Development of the Power Simulation Tool for Energy Balance Analysis of Nanosatellites

  • Kim, Eun-Jung;Sim, Eun-Sup;Kim, Hae-Dong
    • Journal of Astronomy and Space Sciences
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    • v.34 no.3
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    • pp.225-235
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    • 2017
  • The energy balance in a satellite needs to be designed properly for the satellite to safely operate and carry out successive missions on an orbit. In this study, an analysis program was developed using the MATLAB(R) graphic user interface (GUI) for nanosatellites. This program was used in a simulation to confirm the generated power, consumed power, and battery power in the satellites on the orbit, and its performance was verified with applying different satellite operational modes and units. For data transmission, STK(R)-MATLAB(R) connectivity was used to send the generated power from STK(R) to MATLAB(R) automatically. Moreover, this program is general-purpose; therefore, it can be applied to nanosatellites that have missions or shapes that are different from those of the satellites in this study. This power simulation tool could be used not only to calculate the suitable power budget when developing the power systems, but also to analyze the remaining energy balance in the satellites.

Thermodynamic Energy Balance Analysis of Underground Lined Rock Caverns (LRC) for Compressed Air Energy Storage (CAES) (복공식 지하 압축공기에너지 저장공동의 열역학적 에너지수지 분석)

  • Kim, Hyung-Mok;Park, Do-Hyun;Ryu, Dong-Woo;Choi, Byung-Hee;Song, Won-Kyong
    • Tunnel and Underground Space
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    • v.21 no.4
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    • pp.297-306
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    • 2011
  • In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.

Development of Energy Balance Program for Staged-Combustion Cycle of Liquid Rocket Engine (액체로켓엔진 통합 설계를 위한 에너지 발란스 프로그램 개발)

  • Lee, Sang-Bok;Roh, Tae-Seong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.93-97
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    • 2010
  • The energy balance program which can balance the relations among energy, mass flow, pressure in the staged-combustion cycle of the liquid rocket engine has been developed. The modular approach has been chosen for the analysis; the engine cycle consists of the elements from the predefined component analysis program. The engine with the staged-combustion cycle has been decomposed into several principal component modules, such as a thruster chamber, turbopumps, turbines, supply system components and a pre-burner. The program has been verified with comparison of the results to the selected data of the space shuttle main engine.

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Energy Balance by Carbon and Nitrogen Balance Technique in White Leghorn and Rhode Island Red Hens Fed Maize- and Broken Rice-Based Diets

  • Jadhao, S.B.;Tiwari, C.M.;Chandramoni, Chandramoni;Khan, M.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.7
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    • pp.1080-1084
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    • 1999
  • Carbon (C) and nitrogen (N) balance technique was used to determine energy balance in Rhode Island Red (RIR) and White Leghorn (WL) laying hens fed maize-and broken rice (BR)- based diets. Carbon and nitrogen intake and outgo were determined for three days on ad libitum fed diets followed by 2/3 of ad libitum intake for next three days. Carbon analysis was done by using four 'U' tubes in which carbon dioxide released during bomb calorimetry was absorbed on drierite in tube 1 and 2 whereas tube 3 and 4 contained sodalime self indicating granule. Carbon in $CO_2$ was determined by an open circuit respiration system. Energy retention (E, kcal) was calculated as E = 12.386 C (g) - 4.631 N (g). By regressing metabolisable energy (ME) intake on energy balance, maintenance ME requirement of RIR was 128 whereas, that of WL hens was $144kcal/kg\;W^{0.75}/d$. Effciency of utilization of ME for maintenance from BR-based diet in RIR hens was equal but in WL hens it was 11% less than maize-based diet.

A Large-scale Multi-track Mobile Data Collection Mechanism for Wireless Sensor Networks

  • Zheng, Guoqiang;Fu, Lei;Li, Jishun;Li, Ming
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.3
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    • pp.857-872
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    • 2014
  • Recent researches reveal that great benefit can be achieved for data gathering in wireless sensor networks (WSNs) by employing mobile data collectors. In order to balance the energy consumption at sensor nodes and prolong the network lifetime, a multi-track large-scale mobile data collection mechanism (MTDCM) is proposed in this paper. MTDCM is composed of two phases: the Energy-balance Phase and the Data Collection Phase. In this mechanism, the energy-balance trajectories, the sleep-wakeup strategy and the data collection algorithm are determined. Theoretical analysis and performance simulations indicate that MTDCM is an energy efficient mechanism. It has prominent features on balancing the energy consumption and prolonging the network lifetime.