• Journal of Environmental Policy
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• v.11 no.1
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• pp.75-97
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• 2012

The purpose of the paper is to estimate the functions of the energy input efficiency and the energy intensity efficiency, and measure their energy efficiencies for the reduction of greenhouse gases focusing on OECD countries. The efficiency of the traditional energy intensity was rarely connected with the energy efficiencies of the stochastic frontier function. It seems that the energy efficiency by the function of energy input efficiency sensitively responds to the order of GDP, capital stock, labor, and energy input quantity as explanatory variables. In the future, we need to reduce energy quantities by the optimal mix of inputs, and pursuit low-carbon economic growth through the production of the goods consuming small energy.

• Environmental and Resource Economics Review
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• v.30 no.4
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• pp.581-605
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• 2021

The purpose of this study is to provide basic data for improving energy efficiency by estimating the regional energy efficiency in Korea using the stochastic frontier approach beyond the energy intensity that has been traditionally used as an indicator of energy efficiency. In this paper, energy efficiency and energy intensity efficiency were estimated as a stochastic distance function from 1998 to 2018 for 16 cities and provinces in Korea. In addition, the robustness of energy efficiency according to the capital stock estimation methods which had been mixed in previous studies was reviewed. As a result of the analysis, there is a significant change in regional rankings according to the three energy efficiency indicators, so they should be used complementary to each other. Second, while the energy efficiency improved little by little over time, the energy intensity efficiency decreased slightly though. Lastly, energy efficiency by region according to the capital stock estimation method was not robust. Care must be taken in estimating capital stock, which is important in economic analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.652-657
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• 2003

This paper proposes a method to generate virtual intensity field in space. The sound field of a zone enclosing the listener position is controlled to have maximum acoustic intensity to the desired direction. In order to control acoustic intensity of a zone, space-averaged active intensity is introduced. The ratio of space-averaged active intensity and control effort is defined as a cost function and expressed as a function of source control signals. It is shown that the cost function represents radiation efficiency of multiple sources. The control signals maximizing the cost function is found through eigenvalue analysis. The proposed method is verified by numerical simulations performed in free field condition, and the results provide a relation between wavelength and the size of controllable intensity field.

• Computers and Concrete
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• v.16 no.5
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• pp.723-740
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• 2015

In this study, the seismic performance of skewed highway bridges has been assessed by using fragility function methodology. Incremental Dynamic Analysis (IDA) has been used to prepare complete information about the different damage states of a 30 degree skewed highway bridge. A three dimensional model of a skewed highway bridge is presented and incremental dynamic analysis has been applied. The details of the full nonlinear procedures have also been presented. Different spectral intensity measures are studied and the effects of the period on the fragility curves are shown in different figures. The efficiency, practicality and proficiency of these different spectral intensity measures are compared. A suite of 20 earthquake ground motions are considered for nonlinear time history analysis. It has been shown that, considering different intensity measures (IM) leads us to overestimate or low estimate the damage probability which has been discussed completely.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.191-196
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• 2002

In this paper we introduce novel electrode structure for high efficiency discharge. We operate discharge tube under the 0.16 torr pure Xe and apply the sinusoidal wave power to the lamp with 60kHz. We measure the electric power dissipation, plasma parameters, and 828 nm IR intensity. From these data we determine the discharge efficiency, IR intensity/watt, EEDF(Electron energy distribution function). As a result we obtain that the novel electrode structure has better performance in efficiency than that of conventional external electrode system. Also we determine the EEDF for each type of electrode structure by Boltzmann stover, EELNDIF code. The result of Boltzmann equation solving show that the noble electrode system has many high energy electrons compared with the conventional system.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.19-25
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• 2006

Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.

• Convergence Security Journal
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• v.7 no.2
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• pp.1-8
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• 2007

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault (intensity function). In this paper, intensity function of Goel-Okumoto model was reviewed, proposes Kappa (2) and the Burr distribution, which maked out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method. For model determination and selection, explored goodness of fit (the error sum of squares) The methodology developed in this paper is exemplified with a software reliability real data set introduced by NTDS (Naval Tactical Data System)

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.4
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• pp.281-292
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• 2009

The solution of the interface problem or Poisson problem with concave corner has singular perturbation at the interface corners or singular corners. The decoupled dual singular function method (DDSFM) which exploits the singular representations of the solutions was suggested in [3, 9] and estimated optimal accuracy in [10]. The convergence rates consist with theoretical results even for the problems with very strong singularity, with the efficiency depending on parameters used in the methods. Furthermore the errors in $L^2$ and $L^\infty$-spaces display some oscillation, in the cases with meshsize not small enough. In this paper, we present an answer to remove the oscillation via numerical experiments. We observe the effects of parameters in DDSFM, and show the consisting efficiency of the method over the strong singularity.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.144-149
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• 1996

The automation of mesh generation in BEM is bery important in numerical analysys field for the time and efficiency. To be solve this problem Probram and Algorithm, to achive purpose of making input data and automation of mesh generation based on Expert system is developed in this study. And function of this program can be rotating and zooming, To prove efficiency and availability of program in result the stress intensity factor which is criteria of fracture mechanics is caculated and compared with other results.

• Journal of Korea Multimedia Society
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• v.7 no.2
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• pp.156-163
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• 2004

In this paper, we propose an adaptive face region detection and real-time face identification algorithm using face feature evaluation function. The proposed algorithm can detect exact face region adaptively by using skin color information for races as well as intensity and elliptical masking method. And also, it improves face recognition efficiency using geometrical face feature and geometric evaluation function between features. The proposed algorithm can be used for the development of biometric and security system areas. In the experiment, the superiority of the proposed method has been tested using real image, the proposed algorithm shows more improved recognition efficiency as well as face region detection efficiency than conventional method.