• Title, Summary, Keyword: Energy Intensity

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Analyzing the Relation between Energy Intensity, Energy Price and TFP in Korea (에너지 집약도, 에너지 가격 그리고 기술 수준 간의 동태적 관계 분석)

  • Kim, Kijin;Won, DooHwan;Jung, Sukwan
    • Environmental and Resource Economics Review
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    • v.29 no.2
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    • pp.195-217
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    • 2020
  • The improvement of energy intensity is drawing attention as a way to achieve sustainable development. Energy price and technology level are the main factors affecting energy intensity, and empirical studies on the relationship between the variables have been conducted mainly in overseas countries. However, analyzing the relation between energy intensity, energy price and technology has not been studied in Korea. Therefore, this study analyzed the dynamic relationship between energy intensity, energy price, and total factor productivity (TFP) in Korea. As a result of the analysis, the three variables form a long-term equilibrium relationship. The increase in TFP reduces energy intensity in both short and long term, and the long-term effect is greater than short-term effect. On the other hand, energy price do not have a significant impact on energy intensity. Granger causality test results show that energy intensity and TFP granger cause each other, but energy price is weak-exogenous.

Effects of Changes in Exercise Intensity on Resting Metabolic Rate (RMR) and Energy Expenditure in Young Men (운동강도의 차이가 안정시대사량 및 에너지 소비량에 미치는 영향)

  • Kawk Yi-Sub;Jin Young-Wan;Park Chan-Ho
    • Journal of Life Science
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    • v.15 no.3
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    • pp.352-358
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    • 2005
  • The purpose of this study was to examine the effect of various exercise intensity on Resting Metabolic Rate (RMR), excess post exercise energy expenditure (EPEE), and thyroid hormonal changes in trained (TR) and untrained (UT) people. The subject of the present study were divided into two groups and four periods: trained (TR; n=6) and untrained (UT; n=6) group. And the periods were divided as follows; Resting (R), Maximal (M), High intensity (H), and Low intensity (L). The percent body fat and RMR of all subjects were measured at every periods. The RMR was measured early in the morning following a 12-hour fast using MMX3B gas analyzer and blood sample were collected from the anticubital vein to investigate thyroid hormonal (T3, T4, Free T3, Free T4, & TSH) changes. All the RMR values were expressed as absolute value/BSA $(kcal/d/m^2)$. And We also analyzed mean energy expenditure for 30 minutes during and after different intensity exercise. There was significant difference in RMR among different intensity of exercise. in TR (p < .05) not in the UT group. however, there was no significant different percent body fat in TR and in UT group. In the energy expenditure, there was significant different between TR and UT in HEE (high intensity exercise energy expenditure), LEE (low intensity exercise energy expenditure), HEEPE (high intensity exercise energy expenditure post exercise) & LEEPE (low intensity exercise expenditure post exercise). In the hormonal level, there was significant different in T4 level in the TR group at H period and in T4, Free T3, & Free T4 levels in TR group at L period, however there was no significant different in the UT group. The present cross-sectional study was design to investigate the relationship between exercise intensity and RMR. The focus of this investigation was to compare RMR in aerobically trained (TR) and untrained (VI). The relationship among RMR, exercise intensity and percent body fat would best be investigated using MMX3B and body composition analyzer. Each subject completed measurement of percent body fat, RMR, hormone in the period of maximal oxygen uptake exercise (M), high intensity exercise (H), and low intensity exercise (L). From the results, Low intensity of exercise (L), there was a trend for an increased RMR (kcal/day) in the TR not for the UT. This is best explained not by the reduced percent body fat but by the highly induced energy expenditure (during exercise and post exercise energy expenditure) and increased T4, Free T3, and Free T4 hormonal levels in the low intensity exercise for the TR group.

Effects of Different Exercise Intensity on Excess Post Exercise Oxygen Consumption (EPOC), Resting Metabolic Rate (RMR), and Biochemical Variables in Obese and NIDDM Patients (운동 강도의 차이가 제2형 당뇨병 환자와 비만인의 초과산소 섭취량, 안정 시 대사량 및 생화학적 변인에 미치는 영향)

  • Kwak, Yi-Sub;Ku, Woo-Young;Yoo, Byung-In;Jin, Young-Wan;Choi, Kyung-Suk;Cho, Joon-Yong;Woo, Jin-Hee;Hwang, Hye-Jin
    • Journal of Life Science
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    • v.18 no.10
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    • pp.1455-1463
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    • 2008
  • The purpose of this study was to evaluate the effect of various exercise intensity on Excess post exercise energy expenditure (EPEE), Resting Metabolic Rate (RMR),thyroid hormonal changes and biochemical variables in obese and NIDDM patients. The subject of the present study were divided into four groups and four periods: trained (T; n=10), control (C; n=10), obese (O; n=10) and NIDDM (N; n=10) group. And the periods were divided as follows; Resting (RE), Maximal (MA), High intensity (HI), and Low intensity (LI). There was significant difference in RMR among different intensity of exercise. in the T (p<0.05) not in the C, O, and N groups. however, there was no significant different percent body fat among all groups. In the energy expenditure, there was significant different among C, O, N groups compare to T in HIEE (high intensity exercise energy expenditure), LIEE (low intensity exercise energy expenditure), HIEEPE (high intensity exercise energy expenditure post exercise) and LIEEPE (low intensity exercise expenditure post exercise). In the hormonal level, there was significant different in T4 level in the T group at LI period and there was also significant difference in T4, Free T3, & Free T4 levels in T group at LI period, however there was no significant different in the O and N groups except LI period. In the fatigue variables, there was significant different in lactate and ammonia levels in the N group in the period of HI compare to C. The present cross-sectional study was design to investigate the relationship between exercise intensity and RMR in four groups. The focus of this investigation was to compare RMR in aerobically trained (T), control (C), obese (O) and NIDDM (N) group. The relationship among RMR, exercise intensity and percent body fat would best be investigated using Meta Lyzer 3B, MMX3B and body composition analyzer. Each subject completed measurement of percent body fat, RMR, hormone in the period of maximal oxygen uptake exercise (MA), high intensity exercise (HI), and low intensity exercise (LI). From the results, High and Low intensity of exercise, there was a trend for an increased RMR (kcal/day) in the trained groups and control group (in case of LI) not for the obese and N groups. This is best explained not by the reduced percent body fat but by the highly induced energy expenditure (during exercise and post exercise energy expenditure) and increased T4, Free T3, and Free T4 hormonal levels in the low intensity exercise for the T group and sometimes C group.

Analysis on Turbulence Intensity Characteristics at Gimnyeong, Jejudo by Applying IEC 61400 Wind Turbine Standards (IEC 61400 풍력표준을 적용한 제주도 김녕 난류강도 특성분석)

  • Kim, Hyun-Goo;Jeong, Tae-Yoon;Jang, Moon-Seok
    • Journal of the Korean Solar Energy Society
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    • v.30 no.6
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    • pp.59-65
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    • 2010
  • Analysis on turbulence intensity profile depending on wind speed is an important process to set up design condition of wind turbine in terms of fatigue load. This paper tests goodness of fit of turbulence intensity empirical equations suggested by the IEC 61400 Standards with Jejudo Gimnyeong met-tower measurement, which is erected at a seashore. Therefore sea breeze and land breeze coexist. Sea breeze case showed apparent increasing trend of turbulence intensity in a high wind speed regime due to increase of sea surface roughness. However, neither inland wind turbine standard IEC 61400-1 nor offshore wind turbine standard IEC 61400-3 fit such a trend adequately. On the other hand, the modified empirical equation of turbulence intensity of IEC 61400-3 derived from Germany FINO1 application study by considering turbulence intensity behavior in a high wind speed regime showed good agreement with the measurement. Therefore, we can reconfirm and conclude that IEC 61400-3 Ed.1 legislated in 2009 needs to be modified.

Energy Efficiency Improvements in the Korean Industry (한국 제조업의 에너지효율 향상평가)

  • Park, Hi Chun
    • Environmental and Resource Economics Review
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    • v.10 no.2
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    • pp.135-159
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    • 2001
  • This study analyses the energy consumption increase by using a physical production index (PPI) based decomposition method. The energy efficiency of the Korean industry deteriorated to a large extent in the 1992 to 1997 period. This outcome, however, does not contradict the result of a previous study that the physical energy intensities (measured by energy use per production unit) decreased in four Korean energy intensive industries such as steel, cement, petrochemical and pulp and paper in the same period. Although the physical energy intensities in four industries considered decreased significantly, the energy efficiency of the Korean industry deteriorated because the increase in the value-added production was smaller than that in the physical production except for the steel industry. This outcome suggests that the reduction in the physical energy intensity alone will not result in reducing the economic energy intensity, thereby reducing the increase in the energy consumption of the Korean industry. Therefore, it necessitates to restructure the Korean industry towards a higher value-added production and to strengthen energy efficiency improvement efforts in the Korean industry. As the overinvestment in the energy intensive industries caused a deep price fall of Korean products and a reduction of the value added of the Korean industry and with it an increase in the economic energy intensity, a decrease in this intensity will highly depend on reducing the overcapacity in the energy intensive industries which was partly responsible for the currency and economic crisis of 1997.

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Structural intensity analysis of a large container carrier under harmonic excitations of propulsion system

  • Cho, Dae-Seung;Kim, Kyung-Soo;Kim, Byung-Hwa
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.2 no.2
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    • pp.87-95
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    • 2010
  • The structural intensity analysis, which calculates the magnitude and direction of vibrational energy flow from vibratory velocity and internal force at any point of a structure, can give information on dominant transmission paths, positions of sources and sinks of vibration energy. This paper presents a numerical simulation system for structural intensity analysis and visualization to apply for ship structures based on the finite element method. The system consists of a general purpose finite element analysis program MSC/Nastran, its pre- and post-processors and an in-house program module to calculate structural intensity using the model data and its forced vibration analysis results. Using the system, the structural intensity analysis for a 4,100 TEU container carrier is carried out to visualize structural intensity fields on the global ship structure and to investigate dominant energy flow paths from harmonic excitation sources to superstructure at resonant hull girder and superstructure modes.

A Study on the Characteristics of Energy Consumption and Development of Linear Regression Model in Residential Buildings - Focused on the data of 2018 - (주거용 건물의 에너지 소비량 특성 및 선형 회귀모형 개발에 관한 연구 - 2018년 데이터를 중심으로 -)

  • Gang, Nam-Gyu;Kim, Soon-Ho;Kang, Eun-Hye;Choi, Jeong-Min
    • Journal of the Architectural Institute of Korea
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    • v.36 no.7
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    • pp.115-122
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    • 2020
  • Several studies have been conducted on the characteristics of energy consumption of residential buildings. Among them, Choi et al. (2017) and Shin et al. (2018) of the Korea Appraisal Board presented residential energy consumption and unit intensity as of 2015 and 2016 based on the big data information related to energy consumption in Korea. In May 2019, data on energy consumption by domestic administrative area and residential type in 2018 were released to the public through greentogether.go.kr. However, the research results related to the factors affecting energy consumption and unit-level characteristics by housing type and the development of a model for predicting energy consumption and energy unit intensity are still insufficient. Therefore, this study aims to present relevant basic data for GHG reduction of residential buildings by finding the factors and linear regression models that can predict the total energy consumption and energy unit intensity of residential buildings in Korea along with the characteristics of energy consumption based on the national data of 2018 announced on the GreenTogether website.

Wind Farm Design Considering Turbulence Intensity on Complex Terrain (복잡지형에서 난류강도를 고려한 풍력발전단지설계)

  • Park, Mi-Ho;Ko, Kyung-Nam;Huh, Jong-Chul
    • Journal of the Korean Solar Energy Society
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    • v.33 no.6
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    • pp.1-11
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    • 2013
  • The investigation on wind farm design using CFD technique was carried out to reduce turbulence intensity in a wind farm. A potential wind farm in Gasiri of Jeju Island was selected for the design and the commercial S/W of Meteodyn WT was used for applying CFD technique. The initial layout of wind turbines was derived using WindPRO which is mainly used for wind farm design in Korea. Then, the distribution of turbulence intensity on complex terrain was calculated and visible by Meteodyn WT. Based on the distribution, wind turbines were positioned properly. As a result, wind turbines could be deployed at positions with minimum turbulence intensity as well as maximum Annual Energy Production, AEP, using Meteodyn WT. It is necessary to take into account turbulence intensity in wind farm design to avoid wind turbine failure.

Dominant components of vibrational energy flow in stiffened panels analysed by the structural intensity technique

  • Cho, Dae-Seung;Choi, Tae-Muk;Kim, Jin-Hyeong;Vladimir, Nikola
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.5
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    • pp.583-595
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    • 2018
  • Stiffened panels are widely used in naval architecture and ocean engineering, and knowledge about their dynamic behaviour represents important issue in the design procedure. Ordinary vibration analysis consists of natural frequencies and mode shapes determination and can be extended to forced response assessment, while the Structural Intensity (SI) analysis, assessing magnitude and direction of vibrational energy flow provides information on dominant transmission paths and energy distribution including sink positions. In this paper, vibrational energy flow in stiffened panels under harmonic loading is analyzed by the SI technique employing the finite element method. Structural intensity formulation for plate and beam element is outlined, and developed system combining in-house code and general finite element tool is described. As confirmed within numerical examples, the developed tool enables separation of SI components, enabling generation of novel SI patterns and providing deeper insight in the vibrational energy flow in stiffened panels, comparing to existing works.