• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1154-1162
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• 2019

China is undertaking an energy reform from fossil fuels to clean energy to accomplish $CO_2$ intensity (CI) reduction commitments. After hydropower, nuclear energy is potential based on breadthwise comparison with the world and analysis of government energy consumption (EC) plan. This paper establishes a CI energy policy response forecasting model based on national and provincial EC plans. This model is then applied in Fujian Province to predict its CI from 2016 to 2020. The result shows that CI declines at a range of 43%-53% compared to that in 2005 considering five conditions of economic growth in 2020. Furthermore, Fujian will achieve the national goals in advance because EC is controlled and nuclear energy ratio increased to 16.4% (the proportion of non-fossil in primary energy is 26.7%). Finally, the development of nuclear energy in China and the world are analyzed, and several policies for energy optimization and CI reduction are proposed.

• 한국콘텐츠학회논문지
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• 제22권7호
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• pp.187-201
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• 2022

본 연구에서는 우리나라의 전체가구, 노인가구, 1인가구의 에너지 빈곤구조의 동태적 변화를 분석하였다. 이를 위해 TIP 곡선을 도출하였으며 에너지 빈곤강도와 빈곤수준의 변화에 집중하였다. 자료는 통계청 가계동향조사의 연료비에 대한 연간자료와 분기자료를 이용하였는데, 4개 분기 중 난방비의 비중이 높아 에너지 빈곤 문제가 두드러질 수 있는 1분기 자료를 이용한 결과를 제시하였다. 분석 결과, 전체 가구를 대상으로 한 분석에서는 시간이 지남에 따른 빈곤강도와 빈곤수준의 개선이 뚜렷하게 나타나지 않았다. 하지만 노인가구와 1인가구를 대상으로 한 분석에서는 시간이 지남에 따라 빈곤강도와 빈곤수준의 개선이 나타났다. 특히, 1분기 자료를 이용한 분석 결과에서 노인가구와 1인가구의 빈곤강도와 빈곤수준이 뚜렷하게 개선되었다. 전체가구에 비해 노인가구와 1인가구의 빈곤강도와 빈곤수준이 크게 나타났으며, 노인가구 보다 1인가구의 에너지 빈곤이 더 심각한 것으로 나타났다.

• 소음진동
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• 제7권4호
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• pp.589-596
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• 1997

A energy equation for a thin plate and surrounding fluid is derived. The equation essentially determines the relation between internal loss of thin plate, energy of acoustic radiation, and structure intensity. We attempted to use this relation to measure internal loss of thin plate. The significance of this approach is that internal loss at any point of a thin plate can be measured. The quality of this measure is dicated by the accuracy of associated measurement systems such as structure and acoustic intensity measurements. A strain gauge bridge system has been developed to measure structure intensity of thin plate. Its performance is tested by experiments.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.159-171
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• 1997

Sound intensity distributions and energy flow in the near field of dipole source system and flat plate were investigated. First, the effectiveness of complex acoustic intensity was proved by using mathmatical and experimental methods in order to inden- tify noise sources and transmission paths of dipole field which is effected by the presence of neighbouring coherent sources. Next, analytical complex acoustic intensity method was discussed and the characteristics and energy flow of sound induced from the plate are clarified. The velocity of plate obtained from Finite Element Method was used for calculation of complex acoustic intensity in the near field. Finally experimental complex acoustic intensity method using both of active and reactive intensity is vital in devising a strategy for the identification and the reduction of vibration and noise.

• 한국레이저가공학회지
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• 제15권2호
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• pp.11-14
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• 2012

In this paper, we have made a proposal concerning the beam shaping mask(BSM) using random-array slits to control intensity distribution profile of laser beam and demonstrated its proprieties experimentally. When a lot of slits are set out irregularly, diffraction patterns of light does not appear but granularity patterns as a bundle of fibers appear. Intensity distribution profile is controlled by densities distribution of circular slits arrayed randomly because the number of slits and its area means amount of light energy through BSM. Namely as the number of slits in high intensity area is increased and that in low intensity area decreased, amount of light energy is same over all local parts. So gaussian intensity distribution could be changed to flat-top.

• 환경정책연구
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• 제11권1호
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• pp.75-97
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• 2012

본 논문의 목적은 OECD국가를 중심으로 온실가스 감축에 대비하여 에너지 원단위(原單位) 측정의 다른 방법으로서 에너지효율함수와 원단위의 효율함수의 추정을 통하여 에너지효율을 측정하는 것이다. 실증결과는 기존의 전통적 에너지원단위와 확률변경함수에 의한 에너지 효율이 크게 연관되어 있지 않았음을 보여준다. 에너지효율 함수와 원단위 효율함수의 효율도 다소 상이하였다. 에너지 투입효율함수에 의한 에너지효율은 GDP, 자본스톡, 노동, 에너지투입량의 순서로 민감하게 반응하는 것으로 보인다. 향후 투입요소 간 최적 결합을 통한 에너지 절감이 필요하고 에너지 소비가 작은 제품의 생산을 통한 저탄소 경제성장의 추구가 요구된다

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권5호
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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.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.911-919
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• 2021

In this paper, the design stress intensity values for the plate-type fuel assembly for research reactor are presented. Through a tensile test, the material properties of the cladding (aluminum alloy 6061) and structural material (aluminum alloy 6061-T6), in this case the yield and ultimate tensile strengths, Young's modulus and the elongation, are measured with the temperatures. The empirical equations of the material properties with respect to the temperature are presented. The cladding undergoes several heat treatments and hardening processes during the fabrication process. Cladding strengths are reduced compared to those of the raw material during annealing. Up to a temperature of 150 ℃, the strengths of the cladding do not significantly decrease due to the dislocations generated from the cold work. However, over 150 ℃, the mechanical strengths begin to decrease, mainly due to recrystallization, dislocation recovery and precipitate growth. Taking into account the uncertainty of the 95% probability and 95% confidence level, the design stress intensities of the cladding and structural materials are established. The presented design stress intensity values become the basis of the stress design criteria for a safety analysis of plate-type fuels.

• 한국지반환경공학회 논문집
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• 제19권12호
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• pp.15-23
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• 2018

우리나라에서 발생하는 대부분의 토양침식은 물에 의한 토양침식이며 강우와 밀접한 관계를 가진다. 강우로부터 발생하는 토양침식은 토지자원의 손실을 발생시키고 이후 하천에 유입되고 퇴적되어 하천수자원의 관리 및 이용에 많은 어려움을 주고 있다. 최근 기후변화의 영향으로 우리나라에서는 30mm/hr 이상의 집중호우의 발생횟수가 증가하고 있어 단기간에 토양침식이 발생할 가능성이 높아지고 있다. 본 연구에서는 강우의 물리적인 특성을 고려하기 위하여 누적분포함수를 이용하여 강우강도별 강우입자의 분포를 추정하고 단일 호우사상이 가지는 강우에너지를 계산하는 방법을 제안하고자 하였다. 강우에너지 산정공식을 개발하기 위하여 강우강도 0.254~152.4mm/hr에서 측정된 강우입자 자료를 이용하였다. 누적분포함수를 적용하여 산정된 강우에너지는 강우강도의 관계에서 멱함수형태로 증가하는 경향으로 나타났으며, 이 관계로 얻어진 식을 바탕으로 1~80mm/hr 강우강도의 강우 운동에너지를 산정한 결과 $0.03{\sim}48.26Jm^{-2}mm^{-1}$로 나타났다. 강우강도와 강우에너지의 관계를 바탕으로 강우에너지 식을 멱함수로 제시하였다. 본 연구에서 제안된 공식은 한시적으로 설치하는 침사지와 같은 시설물의 규모를 결정하는 계획의 토양침식량을 예측에 활용될 수 있을 것으로 판단된다.

• 한국정밀공학회지
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• 제17권1호
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• pp.83-92
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• 2000

Sound intensity method is well known as a visualization technique of sound field or sound propagation in noise control. Sound intensity or energy flux is a vector quantity which describes the amount and the direction of net flow of acoustic energy at a given position. Especially two dimensional sound intensity method is very useful in evaluating periodic characteristics and acoustic propagation mode of noise source. In this paper, we have studied the noise source Identification, acoustic sound field analysis, and characteristics of noise source of rotary compressor and scroll compressor for air conditioner using complex sound intensity method. Also we proposed a now method of time domain analysis which is used in evaluating of position of noise source in rotary and scroll compressor in this paper This paper presents the advantage, simplicity and economical efficiency of this method by analysing the characteristics of noise source with two dimensional complex sound intensity simultaneously.