• Journal of Korea Port Economic Association
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• v.31 no.1
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• pp.111-125
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• 2015

This study aims at analyzing the influences of Certification of Green Logistics Company on performance and suggesting the implications. Based on previous studies which were related to certificate system of green logistics company and logistics performance, this study established research model and hypothesis, and surveyed the employees who worked in the field of logistics. To analyze the data, factor analysis, reliability analysis, confirmatory factor analysis and structural equation model were applied. The results are as follows. The object management of green logistics gives significantly positive effect to logistics performance and environment performance. The measurement of logistics energy and green gas give meaningful positive effect to logistics performance, environment performance and resource performance. The conversion of green logistics does not give significantly positive effect to any performances. And the effect management of green logistics has significant influence on firm performance.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.529-544
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• 2022

With the global pandemic in the era of the 4th industrial revolution, the business environment of companies was engulfed by rapid volatility and uncertainty. In particular, in order for an organization to have high competitiveness due to the spread of the flexible work system, relationship management with members of the organization and self-directed job crafting are recognized as important key resources. This study aims to investigate how relational energy and resilience within a corporate organization affect job crafting and to verify the effect of job crafting on individual job performance. For empirical research, 400 valid responses to employees of general companies were analyzed by SPSS 26.0 and Smart PLS 3.0. As a result of the analysis, first, it was confirmed that relational energy did not have a positive (+) effect on task crafting. Second, it was found that relational energy had a positive (+) effect on relational crafting and cognitive crafting, respectively. Third, it was found that resilience had a positive (+) effect on both task crafting, relationship crafting, and cognitive crafting that constitute job crafting. Fourth, it was found that job crafting had a positive (+) effect on individual job performance. Based on these research results, we intend to derive academic and practical implications and provide practical help to follow-up researchers and stakeholders.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1342-1343
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• 2011

댐체를 통해 하류 관개용수로 무효방류되는 수자원을 활용한 초소수력 발전가능성에 관한 고찰을 통해 개발 가능한 신재생 에너지 발굴 및 경제성과 타당성에 대하여 검증해 보고자 한다.

• Journal of Energy Engineering
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• v.12 no.2
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• pp.109-117
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• 2003

Because of the difficulty of acquiring new generation sites and right-of-way, additional units have been added to the existing generation sites and the transmission system has been developed into highly meshed configuration. This structural characteristics may cause restriction on the reliable operation of power systems. In other to meet with this problem, the enhancement of system analysis techniques and establishment of appropriate measures have been required in this situation. In addition the deregulation of electric power industry in Korea would require better tools for power system analysis and control. In this paper, exciter system models, speed governor system models and PSS models of EUROSTAG for stability study are developed. Comparison with simulation results of PSS/E is performed for verification of EUROSTAG models.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.98.2-98.2
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• 2011

지구 온난화의 원인이 되는 이산화탄소를 저감하며 유해한 배기가스를 배출하지 않는 수소연료전지자동차(FCV)에 대한 관심이 높아지고 있다. 한국가스안전공사에서 현재 구축하고 있는 평가장비는 이러한 수소연료전지자동차용으로 사용되는 고압용기의 수압반복시험 및 밸브류로 구성된 고압수소저장시스템의 단품 및 시스템 평가를 통한 안전신뢰성 검증을 목적으로 하고 있다. 현재 수소연료전지자동차는 차량이나 부품의 시험 방법에 대한 통일된 기준/표준/시험법이 아직 완전하게 정비되어 있지 않고, 시장에서의 도입 제도, 기준 등이 만들어지고 있는 현실이다. 또한 연료로 수소를 사용하는 도입단계에 있기 때문에, 수소용기가 반복압력변동에 따라 어떤 거동을 나타내는지에 대한 실험관련 연구가 미진한 상태이다. 따라서 수소연료전지자동차용 고압수소저장시스템에 대한 내구성, 안전성 확보를 위하여 수소연료전지자동차에서 중요한 부품인 용기에 대한 반복피로시험이 필요하다. 특히 복합재 용기 분야에서 Type3용기에 대한 높은 안전성과 내구성이 보고되고 있지만 실질적으로 얼마나 다른 용기에 비해 높은 성능을 가지고 있는지 국내에서는 체계적으로 검증된바 없다. 따라서 구축된 수압반복 장비를 이용하여 Type3 용기에 대한 수압반복시험을 실시하였으며, 이를 통해 수소용기의 거동을 확인하고자 한다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.4
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• pp.303-312
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• 2007

There is still a controversy going on about how to model energy dissipation due to breaking over frequency domain. In this study, we unveil the exact structure of energy dissipation using stochastic wave breaking model. It turns out that contrary to our present understanding, energy dissipation is cubically distributed over frequency domain. The verification of proposed model is conducted using the acquired data during SUPERTANK Laboratory Data Collection Project (Krauss et al., 1992). For further verification, we numerically simulate the nonlinear shoaling process of Conoidal wave over a beach of uniform slope, and obtain very promising results from the viewpoint of a skewness and asymmetry of wave field, usually regarded as the most fastidious parameter to satisfy.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.470-477
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• 2012

Climate related policies have been considered due to increase of energy and fossil fuel consumption. Therefore, research has been done to reduce $CO_2$ and to implement green construction. This paper proposes green construction performance metrics for transportation facilities based on previous literature review and survey. The metrics are composed with economic, social, and environment parts and number of metrics are 14, 10, and 12 respectively. The survey was performed to evaluate relevance, clarity, timeliness, comparable, and obtainable of the proposed metrics. Then implementation strategy is also proposed for effective use.

• Environmental and Resource Economics Review
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• v.17 no.3
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• pp.1-29
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• 2008

The goal of this study is to analyze the effects of the second energy tax reform of the transportation sector in Korea. For this purpose, we estimated the elasticities of energy demand(for gasoline, diesel and LPG) by using the ARDL(Auto-Regressive Distributed Lag) Model during the period of 1997 and 2005. We have the empirical results that the demand for diesel would decrease as much as of 382 million barrel per year and the demand for LPG would increase as much as of 20 million barrel per year since 2007. The second energy tax reform would also result in the decrease of 27,346 ton of air pollutants and 0.96 million ton of carbon dioxide per year. This shows that the second energy tax reform would have achieved its own policy goals by reducing energy demand and improving the quality of environment.

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.65-72
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• 2010

In ad-hoc network, the technique to efficiently consume the limited amounts of energy is an important issue since the wireless terminal node is operated on batteries as their energy resource. In order to extend the system lifetime, through a balanced energy consumption, we must delay the situation in which a particular terminal node's energy is depleted and results in system disconnection. Also, the link, which has low reliability due to the mobility of the node, should be avoided considering the key element when setting up the route. The proposed CMLR method in this paper enables to increase the efficiency of energy consumption with a new cost function considering the residue energy of node, error rate of link, and transmission energy consumption. This method is extending the network lifetime and increasing the energy efficiency by compromising the value between the minimization of the transmission energy consumption and maximization of the node's lifetime. Through the simulations the proposed CMLR algorithm was verified by showing better performance over the conventional methods in terms of network lifetime and path efficiency.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.2
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• pp.149-159
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• 1999

본 연구에서는 고유진동수를 사용하여 균열의 위치와 크기를 발견하는 비파괴 균열발견모델을 유도하고 Euler-Bernoulli 보를 대상으로 이 모델의 적합성을 검증하였다. 먼저, 균열위치예측모델과 균열크기예측모델로 이루어진 균열발견체계를 제시하였는데, 균열위치예측모델은 모드민감도와 고유진동수 사이의 선형적인 관계로부터 간접적으로 유도되었으며 균열크기예측모델은 균열발생에 의한 변형에너지의 손실을 진동특성치의 변화와 비교하는 동적 파괴역학적 방법으로부터 유도되었다. 다음으로, 기존에 발표된 양단-자유보에 대한 진동모드 실험결과를 사용하여 균열위치와 균열크기를 예측하고 평가하므로 균열발견모델의 적합성과 적용성을 실험적으로 검토하였다. 대부분의 손상시나리오에서 균열위치와 균열크기 예측치는 실제값과 근사하게 일치하였다.