• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6799-6806
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• 2015

Electric energy consumption is always followed by the introduction of diversity scale-up and state-of-the-art equipments in logistic centers. In order to analyze the status and the characteristic of the electric energy consumption quantitatively, and also to evaluate the efficiency of the electric energy, this research aims to develop an estimation model of standard electric energy consumption for logistic centers. The proposed model applies the thermodynamics theory so as to effectively reflect the peculiarity that the temperature in the logistic center influences the electric energy consumption. And the model consists of the energy consumed by the refrigerator, which can be subdivided into the heat conducted through the wall, the heat convected by the open doors and the heat lost into the goods, and the electric consumption of the machinery equipments. The model also includes a variety of explanatory variables to support an operator of logistics centers in evaluating the efficiency of energy consumption and establishing improvement strategies for energy efficiency. Application of the model developed in this study is discussed with observed data on energy consumption of a logistics center.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.179-188
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• 2015

This study reviewed the type of the project and developmental plan related to ocean energy development in the coastal land boundaries and the ocean, and suggested the efficient scoping method through the diagnosis of the key items of environmental impact assessment (EIA) in the coastal area. The major projects are the construction of tidal power plant, tidal current power plant, and offshore wind power plant in the public water, and also those are the construction of solar power plants in the coastal land boundaries. While the project plans on a large scale such as the construction of tidal power plant, it is important to consider both property of usefulness of the designated areas and harmony analysis with marine space availability based on the adequacy of the site selection and relevance of plan with the master plan for reclamation and strategic environmental assessment (SEA). And also it needs to be considered the careful checkup on the EIA checklist referring to the type of project, effective post-monitoring, and suggestion of mitigating methods to minimize the environmental impacts during the stage of actual environmental impact assessment. Introduction of a system of integrated marine environmental impact assessment should be considered for reasonable and effective manage to developmental projects on the marine spatial area.

• Clean Technology
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• v.23 no.4
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• pp.388-392
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• 2017

In this study, a quantitative environmental impact assessment for the production process of breathable film was conducted employing Life Cycle Assessment (LCA) methodology. Among the various categories, Global Warming (GW) accounted for the highest impact (97%) followed by Human Toxicity (HT). And the key substances of various impact categories included HDPE, PP, and electricity. In the production process, the high impact resulted from mixing process (57%), lamination process (29%), and extruder process (10%). To improve environmental impact, it is necessary to design a new process system that reduces the amount of electricity used and that increases production yields, if raw materials such as HDPE and PP owe excluded.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.44-51
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• 2004

오늘날 대부분의 에너지를 전기에 의존함에 따라 전력사용이 급증하고 부하가 대용량화되어 및 정적 전력공급이 중요한 문제로 대두되었다. 이러한 추세에 따라 송ㆍ배전 설비도 점차 대용량화 및 고전압화 되고 신뢰성을 요구하게 되며, 각종 배전 설비의 제조기술이 더욱 복합 다양하게 발전하고 있다. 그 중 전력계통에서 뇌 혹은 개폐서지 등의 과전압을 흡수ㆍ억제하여, 전력설비와 계통보호를 위해 설치하는 것이 피뢰기이다. 따라서 어떻게 과전압을 낮게 억제할 수 있을까 하는 것이 피뢰기의 가장 중요한 성능이라고 말할 수 있다. (중략)

• KSBB Journal
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• v.25 no.1
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• pp.1-10
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• 2010

Biodiesel is a type of biofuel obtained from bioresources and able to use in diesel vehicles as an alternative/additive to petro diesel. In recent biodiesel research, there are three main issues which include high quality biodiesel, low cost feed stock and a highly efficient biodiesel production process. The sustainable production and use of biodiesel are attracting much attention in the renewable energy field. In this paper, we review some of the literatures related to environmental and economic evaluation for biodiesel production and analysis the issues including life cycle assessment (LCA), global warming potential (GWP), energy consumption, biodiesel production cost, production technologies and feedstock.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2B
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• pp.130-137
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• 2012

In this paper, we propose core and edge router architectures with LPI(Low Power Idle) for reducing energy consumption in OBS networks. The proposed core router architecture is comprised of a BCP switch, a burst switch, line cards and sleep/wake controller for LPI. When the offered load of network is low, sleep/wake controller can change the state of the core router line card from active to sleep state for saving the energy after receiving network control packet. The edge router consists of a switch for access line card, a SCU and OBS edge router line cards. The LPI function in edge router line card is performed through network level control by network control packet, individually. Additionally, PHY/transceiver modules can transition active state to sleep state when burst assemble engine generates new bursts. To evaluate the energy saving performance of proposed architecture with LPI, the power consumption of each router is analyzed by using data sheet of commercial router and optical device. And, simulation is also performed in terms of sleep time of PHY/Transceiver through OPNET.

• Journal of Hydrogen and New Energy
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• v.19 no.1
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• pp.26-34
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• 2008

This study presents an aerodynamic design and an experimental performance test of a turbo air compressor consisted of mixed-flow impeller and curved diffuser for the PEM fuel cell vehicle application. Many studies compare the efficiency, cost or noise level of high-pressure and low-pressure operation of PEM fuel cell systems. Pressure ratio 2.2:1 is considered as design target The goal of compressor design is to enlarge the flow margin of compressor from surge to choke mass flow rate to cover the operational envelope of FCV. Large-scale rig test is performed to evaluate the compressor performance and to compare the effects of compressor exit pipe volume to stall or surge characteristics. The results show that the mixed-flow compressor designed has large flow margin, and the flow margin of compressor configuration with small exit volume is larger than that with large exit volume.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.443-450
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• 2002

본 논문에서는 미국토목학회(ASCE)의 사장교에 대한 첫번째 벤치마크 문제를 이용하여 제어-구조물 상호작용을 고려한 새로운 반능동 제어 기법을 제안하였다. 이 벤치마크 문제에서는 2003년 완공 예정으로 미국 Missouri 주에 건설 중인 Cape Girardeau 교를 대상 구조물로 고려하였다. Cape Girardeau 교는 New Madrid 지진구역에 위치하고, Mississippi 강을 횡단하는 주요 교량이라는 점 때문에 설계단계에서부터 내진 문제에 대하여 자세하게 고려되었다. 상세 설계 도면을 기반으로 하여 교량의 전체적인 거동 특성을 정확하게 나타낼 수 있는 3차원 모델이 만들어졌고, 사장교의 제어 성능에 관련된 평가 기준이 수립되었다. 본 연구에서는 제어 가능한 유체 감쇠기에 속하는 MR 유체 감쇠기를 제어 장치로 제안하였고, 기존 연구에서 MR 유체 감쇠기를 포함한 구조물의 제어에 효율적이라고 검증된 clipped-optimal 알고리듬을 제어 알고리듬으로 사용하였다. 또한, 실제 규모의 MR 유체 감쇠기 실험 결과를 이용하여 수치해석에 이용할 수 있는 동적 모델을 개발하였다. MR 유체 감쇠기는 제어 가능한 에너지 소산장치이며 구조물에 에너지를 가하지 않기 때문에 제안된 제어 기법은 한정입출력 안정성이 보장된다. 수치해석을 통해, MR 유체 감쇠기를 이용한 반능동 제어 기법이 사장교의 응답 감소에 효과적인 방법임을 증명하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1562-1563
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• 2007

본 논문에서는 퍼지 선형추론 기반 지능형 Dimming Converter의 새로운 구조 및 설계 방법론을 제안하고 일련의 수치적인 실험을 통하여 모델 및 시스템을 평가한다. 기존의 형광 램프용 디밍 전자식 안정기는 전용의 디밍 IC를 사용하여 전자식 안정기 대비 최대 83%의 램프 및 안정기의 수명 연장을 가능하게 했다. 하지만 이러한 장점은 사용자가 수동제어를 해야만 하는 불편함 뿐만 아니라, 수동 제어가 불가능 할 경우 램프의 에너지 절약 및 수명 연장이라는 실효를 얻을 수 없다. 따라서 본 논문에서는 퍼지 선형추론 기반의 지능형 이론 및 조도센서를 사용하여 최적의 능동적 디밍제어가 가능한 시스템을 제안하고 제안된 시스템을 안정기에 적용하고 기존 전자식 안정기대비 성능평가를 통하여 지능형 Dimming Converter의 우수성을 보인다.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.4
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• pp.540-545
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• 2007

In this thesis, we introduce and investigate new architectures and comprehensive design methodologies of intelligent dimming converter and evaluate the proposed model and the system through a series of numeric experiments. Electronic ballast enable prolongation of life foy Fluorescent-Lamp and ballast. However, There are no merit in case that user impossible manual control. Therefore in this paper, we put emphasis on the design of electronic ballast based on intelligent dimming converter and the energy saving according to the day-light and the user settings by applying the intelligent model to a fluorescent lamp. Also, we show the superiority of the proposed Intelligent dimming converter through the evaluation of performance with conventional electronic ballast by applying the intelligent model to hardware of systems.