• 자원ㆍ환경경제연구
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• 제29권2호
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• pp.195-217
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• 2020

지속가능한 발전을 달성하기 위한 방안으로 에너지 집약도 개선이 주목받고 있다. 에너지 가격과 기술 수준은 에너지 집약도에 영향을 미치는 주요한 요인으로 세 변수의 연관성에 관한 실증연구는 해외를 중심으로 진행되어왔다. 그러나 우리나라를 대상으로 한 연구는 드물다. 이에 본 연구에서는 우리나라를 대상으로 에너지 집약도, 에너지 가격, 총요소생산성 간 동태적 관계를 분석하였다. 분석 결과 세 변수는 장기균형관계를 형성하며, 총요소생산성의 증가는 장·단기에서 모두 에너지 집약도를 감소시키는 것으로 나타났다. 총요소생산성의 증가가 에너지 집약도 개선에 미치는 효과는 단기보다 장기에 더 큰 것으로 나타났다. 반면 에너지 가격은 에너지 집약도에 유의미한 영향을 미치지 못하였다. Granger 인과성 검정 결과, 에너지 집약도와 총요소생산성은 상호 Granger 인과하지만, 에너지 가격은 약외생적인 것으로 나타났다. 우리나라의 에너지 집약도 개선을 위해서는 전반적인 기술 수준의 개선이 필요하며, 단기적인 처방보다 장기적인 관점에서 정책적 방안을 마련하는 게 바람직하다는 것을 확인할 수 있었다.

• 생명과학회지
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• 제15권3호
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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.

• 지역연구
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• 제14권2호
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• pp.77-83
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• 1998

• 자원ㆍ환경경제연구
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• 제30권4호
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• pp.581-605
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• 2021

본 연구의 목적은 전통적 에너지효율의 지표인 에너지원단위(Energy Intensity)를 넘어 확률적 프런티어 접근으로 우리나라의 지역별 에너지효율성을 추정하고 이를 에너지효율 개선을 위한 기초적 자료로 제공하고자 함이다. 이를 위해 1998 - 2018년 기간 동안의 우리나라 16개 시·도의 에너지효율성 및 에너지원단위 효율성을 확률적 거리함수를 활용하여 추정한다. 부가적으로 선행연구에서 혼재하고 있는 자본스톡 추계방법들에 따른 에너지효율성 순위의 강건성을 살펴본다. 분석 결과 첫째, 세 가지 에너지효율의 지표에 따라 지역의 순위에 상당한 변동이 있었으므로 이들을 상호보완적으로 사용해야 할 것이다. 둘째, 에너지효율성은 시간이 지남에 따라 미미하지만 조금씩 개선된 반면, 에너지원단위 효율성은 미미하지만 하락했다. 마지막으로 자본스톡 추계방법에 따른 지역별 에너지효율성은 강건하지 않았다. 경제분석에서 중요한 자본스톡 추정 시 신중을 기해야 할 것이다.

• 한국태양에너지학회 논문집
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• 제30권6호
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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.

• 자원ㆍ환경경제연구
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• 제10권2호
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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.

• 한국태양에너지학회 논문집
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• 제33권6호
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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.

• Structural Engineering and Mechanics
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• 제16권5호
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• pp.627-641
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• 2003

The structural intensity fields of rectangular plates with single cutout and multiple cutouts are studied. The main objective is to examine the effect of the presence of cutouts on the flow pattern of vibrational energy from the source to the sink on a rectangular plate. The computation of the structural intensity is carried out using the finite element method. The magnitude of energy flow is significantly larger at the edges on the plate near the cutout boundary parallel to the energy flow. The effects of cutouts with different shape and size at different positions on structural intensity of a rectangular plate are presented and discussed. A case study on a plate with two cutouts is also presented.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.61-64
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• 2002

As intensity modulated radiation therapy compared with conventional radiation therapy, tumor target dose increased and normal tissues and critical organs dose reduced. In brain tumor, treatment planning of intensity modulated radiation therapy was practiced in 4MV, 6MV, 15MV X-ray energy. In these X-ray energy, was considered the dose distribution and dose volume histogram. As 4MV X-ray compared with 6MV and 15MV, maximum dose of right optic-nerve increased 10.1 %, 8.4%. Right eye increased 5.2%, 2.7%. And left optic-nerve, left eye, optic chiasm and brainstem incrased 1.7% - 5.2%. Even though maximum dose of PTV and these critical organs show different from 1.7% - 10.1% according to X-ray energies, these are a piont dose. Therefore in brain tumor, treatment planning of intensity modulated radiation therapy in 9 treatment field showed no relation with energy dependency.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.881-887
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• 2000

The interest in evaluation of structural intensity arises for practical reasons, because net energy flow distribution offers information of energy transmission path, positions of sources, and sinks of vibration energy. In this paper, structural intensity analysis of local ship structures using finite element method(FEM) is carried out. The purpose of this analysis is to evaluate the relative accuracy according to mesh fineness. The structural intensity of a stiffened plate varying their mesh fineness is analyzed and the results are compared with those obtained by the assumed made method. As results, the proper mesh size in qualitative/quantitative structural intensity analysis of plate structures is proposed. In addition, the propagation phenomenon of vibration energy is investigated for the L-type plate and box-girder structures.