• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.143-149
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• 2021

This paper proposes length rate measurement for relative efficiency that is a core of data envelopment analysis(DEA). It has been said that the linear programming(LP) is a unique method to get the relative efficiency. This method has drawback that applies fractional LP focusing on each DMU in turn. This paper draws bi-dimensional input-output relational graph and distinguishes between efficient and inefficient DMU. The relative efficiency of inefficient DUM is solve using length rate measurement. As a result of various experimental data, the LP shows mistake of application, but this method gets the correct relative efficiency at all times. Also, this method only gets the relative efficiency for only inefficient DMUs without efficient DUMs that already achieved 100% efficiency. This method solves the relative efficiency of inefficient DUM draws the line to efficient frontier and decides the reference set easily.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.385-388
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• 2004

염료감응형 태양전지는 다공질 $TiO_2$ 전극막, 광감응형 염료, 전해질, 상대전극으로 구성된, 전기화학적 원리를 응용한 신형태양전지이다. 본 연구에서는 백금 상대전극의 제조 방법에 따른 태양전지의 효율 및 특성을 비교하였다. 본 연구에 사용된 백금 상대전극막의 제조 방법은 스퍼터링(sputtering)법 과 전기도금(electroplating)법이다. 두 상대전극의 전기화학적 특성은 cyclic voltammetry와 Imepedance spectroscopy 측정을 통하여 비교하였다. 두 전극이 태양전지의 효율 및 특성에 미치는 영향은 단위 셀 태양전지를 제조하여 단파장 하에서 $350nm{\sim}700nm$의 파장별 효율을 측정함으로써 조사하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.6
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• pp.70-75
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• 2000

This paper examines the performance of adaptive filtering algorithms in relation to the asymptotic relative efficiency (ARE) of estimators. The adaptive filtering algorithms are Hybrid II and modified zero forcing (MZF) algorithms. The Hybrid II and MZF algorithms are simplified forms of the LMS algorithm, which use the polarity of the input signal, and polarities of the error and input signals, respectively. The ARE of estimators for each algorithm is analyzed under the condition of the same convergence speed. Computer simulations for adaptive equalization are performed to check the validity of the theory. The explicit expressions for the ARE values of the Hybrid II and MZF algorithms are derived, and its results have similar values to the results of computer simulation. It also revealed that the ARE values depend on the correlation coefficients between input signal and error signal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.302-309
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• 2017

The influence of the pile diameter, center to center pile spacing, internal friction angle of embankment soil, and height of embankment on the arching efficacy of the embankment pile was investigated. The arching efficacy, which was derived by the arch model developed in the embankment soil was calculated using two methods, one that considers crown failure of the arch and the other that considers load on the pile cap and critical relative spacing ratio for which the arching efficacy calculated by the two methods are the same. According to the computed results in this study, the arching efficacy calculated from a consideration of the load on pile cap governs when the relative spacing ratio becomes smaller and that calculated from the theory of crown failure governs when the relative spacing ratio becomes larger. The critical relative spacing ratio below which the arching efficacy calculated from a consideration of the load on pile cap governs the design decreases with increasing value, which is defined by the ratio of the pile diameter to the pile center to center spacing. Critical relative spacing ratios, which correspond to the values of 0.5 and 0.2 were 0.35 and 0.85, respectively. Considering the computed results, the critical relative spacing ratio decreases with increasing Rankine passive earth pressure coefficient and critical relative spacing ratios, which correspond to values of 5 and 2, were 0.23 and 0.85, respectively. The arching efficacy, which corresponds to the area ratio of 9%, was 54% and the one that corresponds to the value of 3 was 61%; the critical relative spacing ratios, which correspond to those arching efficacies, were greater than 0.5.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.329-331
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• 2000

G-Machine은 수행하는데 있어서 그래프를 표현하기 위해 많은 그래프 공간을 필요로 한다. 이를 줄이기 위한 노력으로 최근 태그 옮김을 이용한 ZGM이 설계되었다. 하지만, ZGM은 태그와 자료의 분리로 인하여 많은 상대 주소를 갖게 되어 실행 시간 부담이나 공간 활용 부담이 된다. 본 논문에서 우회 노드 장소에 자료를 중복 사용하는 방법을 이용하여 G-Machine에서 필요로 하는 그래프 공간을 절약한 poGM(Point Over lapped GM)을 제안한다. poGM은 ZGM과 같이 상대 주소를 사용하지만, 일반적인 노드 나타내는데 ZGM과 달리 자료의 분리가 일어나지 않고, 상대 주소를 줄일 수 있으며, 실험을 통하여 공간 효율과 시간 효율이 높은 것을 보인다.

• The Korean Journal of Applied Statistics
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• v.12 no.1
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• pp.109-124
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• 1999

일반적으로 오차항이 자기상관되어 있는 선형회귀 모형에서는 회귀계수에 대한 보통최소제곱추정량이 효율적이지 못 하다고 알려져 있다. 그러나 이러한 일반화선형회귀모형에서 독립변수의 형태에 따라서는 OLSE의 사용 가능성을 제시하는 모형이 있다. 본 연구에서는 오차항이 일차 이동평균 과정을 따르는 선형회귀모형에서 여러 추정량들 (GLSE, APX, MAPX)에 대한 OLSE의 상대효율함수를 유도하고 비교 분석하고자 한다. 특히 소표본에서 정확한 상대효율값을 구하여 OLSE의 효율성이 크게 떨어지지 않거나 효율성이 나은 회귀모형들을 제시한다.

• Polymer(Korea)
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• v.37 no.5
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• pp.656-662
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• 2013

The flexible patterned cover film was made by a simple solution coating process using polymethyl methacrylate (PMMA) solution with glass beads. The effect of patterned cover film on the efficiency of solar cell has been investigated. It was found that the relative solar cell efficiency increased up to 3.4% with the incident light angle between $0-90^{\circ}$ by the sphere shape of glass bead coated on the film surface. This was understood that the loss of transmittance and scattering due to the light directional dependency on solar cell were minimized because the light entered glass beads normal to its surface regardless of incident light angle. The maximum relative solar cell efficiency was achieved when glass bead shape on the film is hemisphere and the relative efficiency increased with increasing the amount of glass bead on the film surface. However, too much glass beads on the film surface resulted in the lower relative solar cell efficiency due to the lowering of transmittance as well as the occurring of light interference.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.262-267
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• 2016

In this study, we present an excellent approach for easily and uniformly immobilizing Pt, Au and bimetallic PtAu nanoparticles (NPs) on a multi-walled carbon nanotube (MWNT)-coated layer through dry plasma reduction. The NPs are stably and uniformly immobilized on the surface of MWNTs and the nanohybrid materials are applied to counter electrode (CE) of dye-sensitized solar cells (DSCs). The electrochemical properties of CEs are examined through cyclic voltammogram, electrochemical impedance spectroscopy, and Tafel measurements. As a result, both electrochemical catalytic activity and electrical conductivity are highest for PtAu/MWNT electrode. The DSC employing PtAu/MWNT CE exhibits power conversion efficiency of 7.9%. The efficiency is better than those of devices with MWNT (2.6%), AuNP/MWNT (2.7%) and PtNP/MWNT (7.5%) CEs.

• Convergence Security Journal
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• v.23 no.2
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• pp.95-102
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• 2023

The purpose of this paper was to confirm the operational level of the military department of universities, which plays a key role in the officer training process, through empirical research and confirm meaningful results for improvement. There are 11 university military departments operated through the Army, agreements, and semi-agreement, and the Data Envelopment Analysis (DEA) was applied from the perspective of resource input and performance for each university's military department operation to analyze relative efficiency and confirm specific directions for improvement. As a result of operational efficiency analysis, 6 DMUs (Decsision Making Unit) were found to be efficient in the BCC model out of 11 DMUs, and the evaluation results could be confirmed through classification of efficient and inefficient groups through data capture analysis. This paper may be of practical value in that it checks the efficiency of the comparative university military departments and confirms specific information for development through the DEA-Additive model that reflects several evaluation factors at once. Through this, the operators of each university's military department are admitted.

• Journal of Technology Innovation
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• v.3 no.1
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• pp.157-184
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• 1995

본 연구는 한국 제조업의 기업별 <패널>자료를 이용하여 확율 적 생산함수를 추정한 다음, 우리 나라의 주종 수출산업인 섬유산업과 전자산업의 기술적 효율성이 1980년대에 하락한 이유를 규명하기 위하여 동종산업내의 각 기업들의 기술적 효율성의 결정요인을 계량분석을 통해 분석하였다. 성장산업인 전자산업과 사양산업인 섬유산업의 산업 내 (intra-industry) 기술적 효율성의 결정요인은 상하였다. 성장산업인 전자산업의 경우, 상대적인 기업의 크기와 노동비용의 상대적 크기는 기술적 효율성과 각각 정의 관계를 보이고 있는데 비해, 사양산업인 섬유산업의 경우, 총 매출액에서 수출이 차지하는 비중과 기술적 효율성과 반의 관계를 보였다. 즉 1980년대 섬유산업의 기술적 효율성이 하락한 중요한 요인은 동 산업의 수출부진과 상대적인 노동비용의 상승을 들 수 있으며, 성장산업인 전자산업의 경우는 일부 대기업의 집중도 심화가 동 산업의 평균적 기술적 효율성의 하락요인이 되었음을 알 수 있다. 따라서 본 연구는 경쟁의 촉진과 기업 집중도의 완화가 기술적 효율성을 향상시키는 데 중요하다는 점을 보여주고 있다.