• Journal of the Korean Vacuum Society
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• v.3 no.2
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• pp.198-202
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• 1994

Zn0.5Mg0.5Te 및 Zn0.5Mg0.5Te:Co 단결정을 온도진동법을 응용한 화학수송법으로 성장시켰고, 광 학적 energy gap의 온도의존성은 Varshni의형식에 잘 적용되었다. 광학적 energy gap의 온도의존성으 로부터 열역학 기본함수인 entropy, enthalpy, heat capacity를 구했다.

• 대한방사선방어학회:학술대회논문집
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• 2011.11a
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• pp.150-151
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• 2011

• Journal of Korean Society of Industrial and Systems Engineering
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• v.9 no.13
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• pp.45-50
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• 1986

본 연구에서 고찰한 surrogate relaxation은 Lagrangian relaxation 방법과는 달리 제약식들을 선형조합으로 묶어 문제를 푼다. 수리계획 분계가 convexity를 만족하지 못하는 경우에는 Lagrangian의 경우와 마찬가지로 surrogate gap이 발생한다. Lagrangian 쌍대이론을 토대로 surrogate optimality condition을 알아보고 수리계획법의 특별 형태인 정수선형계획법에 적용해 보았다. 일반적으로 surrogate gap은 Lagrangian gap 보다 작기 때문에 좀더 근사하게 원 문제의 최적 목적 함수값에 접근할 수 있다. 따라서 branch and bound 알고리즘을 개발할 때 중요한 정보를 제공하는 것이다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.693-699
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• 1998

In this work $Cd_4GeS_6:Co^{2+}$(0.5mole%) single crystals were grown by the chemical transporting reactiov(CTR) method using high purity(6N) elements. The grown single crystals crystallized in a monoclinic structure(space group Cc). The direct optical energy gap of this single crystals was found to be 2.445eV at 300K and the temperature dependence of optical energy gap was fitted well to Varshni equation. But at temperatures lower than 70K an anomalous temperature dependence of the optical energy gap was obtained. This anomalous temperature dependence accored well with the anomalous temperature dependence of the unit cell volume. Also, the entropy, enthalpy and heat capacity were deduced from the temperature dependence of optical energy gaps.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.194-195
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• 2004

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.943-946
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• 2007

The vibration and noise characteristic of the Axial-gap motor for an air conditioner were analyzed. Experimental Modal Analysis was performed to understand the vibration characteristic of the motor. The noise of motor was measured in a dead room. Finite Element Method was performed to find the vibration characteristic of the motor by using ABAQUS program.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.388-391
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• 2015

본 연구에서는 탄소로 이루어진 그래핀과 붕소와 질소의 합성물인 h-BN을 적절하게 섞어, 밴드갭(band gap)의 변화를 범밀도함수이론(DFT)을 통하여 설계하려고 한다. 본 연구에서 태양전지의 가장 높은 효율을 가지기 위한 밴드갭 1.2eV 가지는 모델을 설계하려고 한다. Armchair 방향으로 B와 N을 도핑을 하여 width에 따른 Nanorribbons 형태를 만들어 밴드갭(band gap)의 변화를 살펴 볼 것이다. 그래핀과 h-BN을 각각 고정시키며 다른 한쪽의 width를 늘리면서 밴드갭(band gap)의 변화도 살펴 볼 것이다. 그래핀와 h-BN의 비가 5:3일 때 1.14eV로 가장 1.2eV에 비슷하게 나왔고 3:5일 때 1.12eV로 그 다음으로 가장 가까운 결과를 얻을 수 있엇다. 또한 비슷한 밴드갭을 가지더라도 그러한 원자 구조가 얼마나 안정적인지를 알기 위해 cohesive 에너지를 계산 할 것이다. 이러한 결과로 인해 태양에너지 연구에 큰 이바지를 할 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.31-36
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• 2002

In this work $Cd_{4}GeSe_{6}$ and $Cd_{4}GeSe_{6}:Co^{2+}$ single crystals were grown by the chemical transport reaction method and the structure of $Cd_{4}GeSe_{6}$ and $Cd_{4}GeSe_{6}:Co$ single crystals were monoclinic structure. The temperature dependence of optical energy gap was fitted well to Varshni equation. Also, the entropy, enthalpy and heat capacity were deduced from the temperature dependence of optical energy gap.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1939-1946
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• 2011

Expander graphs are useful in the design and analysis of communication networks. Mukhopadhyay et. al introduced a method to generate a family of expander graphs based on nongroup two predecessor single attractor CA(Cellular Automata). In this paper we propose a method to generate a family of expander graphs based on 60/102 Null boundary CA(NBCA) which is a group CA. The spectral gap generated by our method is larger than that of Mukhopadhyay et. al [12]. As an application we give an algorithm which generate one-way functions whose security lies on the combinatorial properties of our expander graphs. the one-way function using d-regular graph generated by the 60/102 NBCA is based on the Goldreich's construction [5].

• Journal of Labour Economics
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• v.37 no.4
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• pp.113-141
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• 2014

This paper examines the occupational gender wage gap in the Korea labor market. This paper classifies occupations into three(the blue-collar profession, white-collar profession and female-dominated profession) according to job characteristics and female worker's ratio. To analyze occupational gender wage gap, this paper uses Mincer's wage equation(1974) and Oaxaca model(1973). The results are listed below. First, the gender wage gap is growing in all occupations. Second, the cause of increasing gender wage gap varies in different occupations.