• 제목/요약/키워드: Energy approach

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The Relationship Between Income Inequality and Energy Consumption: A Pareto Optimal Approach

  • NAR, Mehmet
    • The Journal of Asian Finance, Economics and Business
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    • 제8권4호
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    • pp.613-624
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    • 2021
  • This paper analyzes the relationship between income distribution and energy consumption from a Pareto optimal approach. For this purpose, the causality relationship between electricity consumption per capita (kWh) with respect to country groups and energy consumption per capita (kg of oil equivalent) along with gross domestic product per capita was analyzed. In addition to this purpose, a Pareto analysis was conducted to determine the countries with the highest per capita national income, how much of the world total energy they consume, and whether the law of power in the energy and electricity markets exists. Finally, the impact of official development assistance provided to low-income countries by high-income countries on the low-income countries' electricity and energy consumption was analyzed. In other words, it was questioned whether pareto redistribution policies serve the purpose or not. The Engle-Granger causality approach was used in the analysis of the causality relationship between variables. Our analysis indicated that, first, the energy data of the country groups may be inadequate in revealing income inequalities. Second, the existence of Pareto law of power and global income inequality can be explained based on energy data. Finally, Pareto optimal redistribution policies to eliminate income inequality remain inadequate in practice.

Optimal Control Approach for a Smart Grid

  • Imen Amdouni;Naziha Labiadh;Lilia El amraoui
    • International Journal of Computer Science & Network Security
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    • 제23권12호
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    • pp.194-198
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    • 2023
  • The current electricity networks will undergo profound changes in the years to come to be able to meet the growing demand for electricity, while minimizing the costs of consumers and producers, etc. The electricity network of tomorrow or even the intelligent « Smart Grids » network will be the convergence of two networks: the electricity network and the telecommunications network. In this context falls our work which aims to study the impact of the integration of energy decentralization into the electricity network. In this sense, we have implemented a new smart grid model where several coexisting suppliers can exchange information with consumers in real time. In addition, a new approach to energy distribution optimization has been developed. The simulation results prove the effectiveness of this approach in improving energy exchange and minimizing consumer purchase costs and line losses.

A new approach for quantitative damage assessment of in-situ rock mass by acoustic emission

  • Kim, Jin-Seop;Kim, Geon-Young;Baik, Min-Hoon;Finsterle, Stefan;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • 제18권1호
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    • pp.11-20
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    • 2019
  • The purpose of this study was to propose a new approach for quantifying in situ rock mass damage, which would include a degree-of-damage and the degraded strength of a rock mass, along with its prediction based on real-time Acoustic Emission (AE) observations. The basic approach for quantifying in-situ rock mass damage is to derive the normalized value of measured AE energy with the maximum AE energy, called the degree-of-damage in this study. With regard to estimation of the AE energy, an AE crack source location algorithm of the Wigner-Ville Distribution combined with Biot's wave dispersion model, was applied for more reliable AE crack source localization in a rock mass. In situ AE wave attenuation was also taken into account for AE energy correction in accordance with the propagation distance of an AE wave. To infer the maximum AE energy, fractal theory was used for scale-independent AE energy estimation. In addition, the Weibull model was also applied to determine statistically the AE crack size under a jointed rock mass. Subsequently, the proposed methodology was calibrated using an in situ test carried out in the Underground Research Tunnel at the Korea Atomic Energy Research Institute. This was done under a condition of controlled incremental cyclic loading, which had been performed as part of a preceding study. It was found that the inferred degree-of-damage agreed quite well with the results from the in situ test. The methodology proposed in this study can be regarded as a reasonable approach for quantifying rock mass damage.

Bayesian-based seismic margin assessment approach: Application to research reactor

  • Kwag, Shinyoung;Oh, Jinho;Lee, Jong-Min;Ryu, Jeong-Soo
    • Earthquakes and Structures
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    • 제12권6호
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    • pp.653-663
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    • 2017
  • A seismic margin assessment evaluates how much margin exists for the system under beyond design basis earthquake events. Specifically, the seismic margin for the entire system is evaluated by utilizing a systems analysis based on the sub-system and component seismic fragility data. Each seismic fragility curve is obtained by using empirical, experimental, and/or numerical simulation data. The systems analysis is generally performed by employing a fault tree analysis. However, the current practice has clear limitations in that it cannot deal with the uncertainties of basic components and accommodate the newly observed data. Therefore, in this paper, we present a Bayesian-based seismic margin assessment that is conducted using seismic fragility data and fault tree analysis including Bayesian inference. This proposed approach is first applied to the pooltype nuclear research reactor system for the quantitative evaluation of the seismic margin. The results show that the applied approach can allow updating by considering the newly available data/information at any level of the fault tree, and can identify critical scenarios modified due to new information. Also, given the seismic hazard information, this approach is further extended to the real-time risk evaluation. Thus, the proposed approach can finally be expected to solve the fundamental restrictions of the current method.

콘크리트 파괴역학을 이용한 철근콘크리트 인장부재의 균열성장 해석 (Cracking Analysis of Reinforced Concrete Tension Members with Concrete Fracture Mechanics)

  • 홍창우;윤경구;양성철
    • 콘크리트학회논문집
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    • 제12권1호
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    • pp.3-12
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    • 2000
  • A fracture energy concept proposed by Ouyang and Shah's fracture mechanics approach was used to predict cracking of reinforced concrete members subjected to tension. In this approach, fracture properties in plain concrete which incorporate the presence of the fracture process zone are first determined from the generalized size effect method, then fracture energy required for crack propagation with the same dimension and material properties are evaluated using an R-curve. Subsequently taking into account the material properties in Ouyang and Shah's approach, a theoretical analysis to predict the mechanical behavior of reinforced concrete members subjected to tension was performed and compared to observed experimental results. It is seen that the predicted average crack spacing curves agree well with the experimental results, whereas the analytical method seems to predict lower values for this study. The analytical approach predicts well responses of stress-strain curves before and after the first crack is formed. It is concluded from this study that a fracture energy concept based on the R-curve and the generalized size effect method is a rational approach to predict cracking of reinforced concrete members subjected to tension.

위기영기의 순환에 관한 수기의학적 소고 (Manual Medicine Study about Circulation of Meridian WiGi, YoungGi)

  • 김규섭
    • 척추신경추나의학회지
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    • 제15권2호
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    • pp.33-41
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    • 2020
  • Objectives The purpose of this report was to study the circulation of meridian WiGi, YoungGi, from the viewpoint of manual medicine. Methods First, the Korean Medical approach analyzes documents about the circulation of meridian WiGi, YoungGi, and the biomechanical approach is to analyze documents about kinetic force and kinematic movement. The third inherent energy approach is to analyze documents about craniosacral rhythm and visceral motility. Finally, it is to study the correlation between the circulation of meridian WiGi, YoungGi, and the viewpoint of biomechanics force and movement, the inherent energy of manual medicine. Results Meridian WiGi is fast, powerful, and changeful. It circulates through the head and extremities in the daytime and visceral organs at night. The deviation pelvis and distorted thoracic cage create kinetic force and kinematic movement. Meridian YoungGi is very small and soft energy and circulates meridians and visceral organs permanently. Craniosacral rhythm and visceral motility radiate continuously from cranial and visceral organs to the whole body. Conclusions Circulation of meridian WiGi is closely related to the biomechanical approach. In addition, circulation of meridian YoungGi is closely related to the inherent energy approach.

Energy-efficiency enhancement and displacement-offset elimination for hybrid vibration control

  • Makihara, Kanjuro
    • Smart Structures and Systems
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    • 제10권3호
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    • pp.193-207
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    • 2012
  • New insights into our previously proposed hybrid-type method for vibration control are highlighted in terms of energy analysis, such as the assessment of energy efficiency and system stability. The hybrid method improves the bang-bang active method by combining it with an energy-recycling approach. Its simple configuration and low energy-consumption property are quite suitable especially for isolated structures whose energy sources are strictly limited. The harmful influence of the external voltage is assessed, as well as its beneficial performance. We show a new chattering prevention approach that both harvests electrical energy from piezoelectric actuators and eliminates the displacement-offset of the equilibrium point of structures. The amount of energy consumption of the hybrid system is assessed qualitatively and is compared with other control systems. Experiments and numerical simulations conducted on a 10-bay truss can provide a thorough energy-efficiency evaluation of the hybrid suppression system having our energy-harvesting system.

Energy-based damage-control design of steel frames with steel slit walls

  • Ke, Ke;Chen, Yiyi
    • Structural Engineering and Mechanics
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    • 제52권6호
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    • pp.1157-1176
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    • 2014
  • The objective of this research is to develop a practical design and assessment approach of steel frames with steel slit walls (SSWs) that focuses on the damage-control behavior to enhance the structural resilience. The yielding sequence of SSWs and frame components is found to be a critical issue for the damage-control behavior and the design of systems. The design concept is validated by the full-scale experiments presented in this paper. Based on a modified energy-balance model, a procedure for designing and assessing the system motivated by the framework regarding the equilibrium of the energy demand and the energy capacity is proposed. The damage-control spectra constructed by strength reduction factors calculated from single-degree-of-freedom systems considering the post stiffness are addressed. A quantitative damage-control index to evaluate the system is also derived. The applicability of the proposed approach is validated by the evaluation of example structures with nonlinear dynamic analyses. The observations regarding the structural response and the prediction during selected ground motions demonstrate that the proposed approach can be applied to damage-control design and assessment of systems with satisfactory accuracy.

머신러닝 기법을 활용한 공장 에너지 사용량 데이터 분석 (Machine Learning Approach for Pattern Analysis of Energy Consumption in Factory)

  • 성종훈;조영식
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제8권4호
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    • pp.87-92
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    • 2019
  • 본 연구에서는 머신 러닝 기법을 활용하여 공장에서 발생하는 에너지 사용량에 대한 데이터 분석 및 패턴 추출에 대해 다룬다. 통계학이나 기존의 방법들은 몇 가지 물리적 특성을 반영하는 수학적 모델을 구축하는 반면, 머신 러닝을 통한 접근방법은 데이터 학습을 통하여 모델의 계수들을 결정하게 된다. 기존의 방법들은 특정한 구조를 갖는 수학적 모델을 구축해야 한다는 어려움이 있으며 과연 데이터의 특징들을 잘 반영하는지에 대한 의문이 존재했다. 그러나 머신 러닝을 통한 방법은 사람이 구축하기 어려운 작업들을 용이하게 구축한다는 장점을 가지고 있기 때문에 데이터 간의 관계를 파악하기에 더 효율적이라는 장점을 가지고 있다. 공장의 에너지 소비에 직접적으로 영향을 끼치는 요소들이 존재하며 이러한 전력 소비는 시간에 따른 데이터로 나타나게 된다. 각 요소들로부터 발생하는 소비 전력을 계측하고 데이터 베이스를 구축하기 위해 각 요소에 센서를 장착하였다. 취득된 데이터에 대해 전처리 과정 및 통계적인 분석을 거친 뒤, 머신 러닝을 통해 패턴을 분석하는 과정을 거쳤다. 이를 통해 공장에서 발생하는 소비 전력 데이터에 대한 패턴 분석을 진행하였다.

Uncertain-parameter sensitivity of earthquake input energy to base-isolated structure

  • Takewaki, Izuru
    • Structural Engineering and Mechanics
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    • 제20권3호
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    • pp.347-362
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    • 2005
  • The input energy to a base-isolated (BI) building during an earthquake is considered and formulated in the frequency domain. The frequency-domain approach for input energy computation has some notable advantages over the conventional time-domain approach. Sensitivities of the input energy to the BI building are derived with respect to uncertain parameters in the base-isolation system. It is demonstrated that the input energy can be of a compact form via the frequency integration of the product between the input component (Fourier amplitude spectrum of acceleration) and the structural model component (so-called energy transfer function). With the help of this compact form, it is shown that the formulation of earthquake input energy in the frequency domain is essential for deriving the sensitivities of the input energy to the BI building with respect to uncertain parameters. The sensitivity expressions provide us with information on the most unfavorable combination of the uncertain parameters which leads to the maximum energy input.