• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.253-264
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• 2018

The GPS radiosonde is designed to conduct a full synoptic sounding to balloon burst using data generated from precision meteorological sensors and the GPS satellite network. The GPS radiosonde include proven, accurate temperature, humidity and capacitance aneroid pressure sensors. The atmospheric boundary layer was intensively observed in three islands of the west sea from 18 LST on March 9, 2016 to 06 LST on March 12, 2016. We investigated the restriction of nocturnal stable layer and rather the development of the mixed layer at night. On March 9, nocturnal mixed layer was developed by buoyancy heat flux. On the other hand, on March 10, the shear production was higher especially at 21 LST when the mixed layer height was the highest during the intensive observation period. The wind shear and the surface heat flux which produce the turbulent kinetic energy played an important role to grow the mixed layer even at night.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.65-72
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• 2024

Green Hydrogen demonstration complex is under conduction in Jeju island which is rich in renewable energy resources and will produces green hydrogen using a water electrolysis systems. In order to check durability of long-term operation, AST(accelerated stress test) was applied and the power pattern based on Jeju Island's wind power was applied. After 800 hours of repeated application of low current and high current, the performance of the PEM water electrolysis cell was reduced by up to 10% and by about 5.5% in operating conditions. As the result of impedance analysis, it can be seen that the electrode polarization resistance greatly increased than ohmic polarization resistance. In addition, when the durability evaluation was conducted by applying the wind power pattern of Jeju Island, the performance of the PEM water electrolysis cell showed up to 1.6% and a decrease of less than 1% in operating conditions. As a result of the impedance, it can be seen that the change of ohmic resistance and electrode polarization resistance is small.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.1
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• pp.25-33
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• 2019

In the plant industry, the share of equipment accounts for 45 ~ 75%, which is very high. It is a traditional plant centered on processes and reactions like petroleum and chemical plants. Renewable energy generation plants such as wind power generation and solar power generation are equipment-centric plants. Equipment-centric plants are very important not only in the EPC phase but also in the operation and management phase. The procurement of equipment for plant operation and management can be divided into make and buy. Make is a method of producing equipment itself, and buy is a method of procuring equipment from the outside. The procurement method of the equipment directly affects the plant operation and management cost. In this study, the decision making of equipment procurement method for plant operation and management is defined as 4 phase. Each phase is selection of procurement decision-making objects, technology strategy perspective, finance perspective, and production perspective. In detail, we defined selection process of procurement decision-making objects and technology strategy perspective process. We will contribute to the enhancement of the competitiveness of the plant operation and management area by carrying out researches on the process and application examples of financial and production perspectives in the future.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.615_616
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• 2009

유한요소해석(Finite Element Analysis)을 통한 풍력발전기 최적설계시, 해석 특성상 발생하는 막대한 소요시간의 개선이 필요하다. 본 논문에서는 연간 에너지 생산량(Annual Energy Production : AEP)의 최대화를 목표로 GA(Genetic Algorithm)와 MADS(Mesh Adaptive Direct Search)를 결합한 혼합 알고리즘을 이용하여 최적설계를 수행하였다. 또한, 혼합 알고리즘과 병렬분산 유전알고리즘을 이용한 최적설계의 해석 소요시간을 비교 및 검토하였다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.647-648
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• 2008

풍력발전기 최적 설계시, 해석특성상 발생하는 막대한 계산 시간문제를 개선하기 위해, 본 논문에서는 최대 연간 에너지 생산량(AEP)을 위한 풍력발전기 최적설계를 빠른 탐색 기법인 MADS(Mesh Adaptive Direct Search)를 기반으로 최적화를 수행하였다. 또한, MADS와, 병렬 분산컴퓨팅 시스템과 결합된 유전알고리즘(Genetic Algorithms)간의 최적화 수행시간을 비교하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.141-142
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• 2011

The increase in oil prices and the rising environmental concerns are boost the electric vehicle supply. Vehicle manufactures understand this trend quite well and plan to increase the production of electric vehicle(EV) such as Nissan LEAF and GM VOLT etc.. The growth of intermittent renewable energy sources such as solar and wind power requires utilities to find additional grid coupled energy storage and regulation capacity. EVs have a battery pack and a charger. The charger can be able to deliver power back to the grid from the vehicle's battery as well as charge the battery. The concept of deploying EVs to stabilize the electric power grid is generally referred to as Vehicle-to-Grid(V2G). We present the grid service using V2G.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.58.2-58.2
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• 2011

본 연구에서는 5MW급 수평축 풍력터빈 블레이드에 대해 국내 서남해안의 풍속특성을 고려한 최적설계를 수행 하였다. 최적설계를 수행하기 위해 블레이드 해석은 Blade Element and Momentum Theory를 이용 하였으며, 설계 시 적용된 기저형상은 NREL에서 제안한 5MW급 풍력터빈 블레이드을 선정하였다. 최적설계를 수행하기 전 설계에 사용된 설계변수들이 풍속에 대해 어떠한 경향을 가지고 있는지 알아보기 위해 Parametric Study를 수행 하였으며, 최적설계는 다목적 최적화 유전 알고리즘인 NSGA-II를 이용하여 평균풍속이 낮은 서남해안의 연간에너지 생산량과 설비이용률을 최대화하였다. 최적화 결과들로부터 설계 조건에 맞는 최적해를 도출 할 수 있었으며, 이를 통해 기저형상의 연간에너지 생산량 및 설비이용률을 보다 향상 시킬 수 있었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.641-647
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• 2014

Stand-alone PV systems and grid-connected distribution lines operating independently with out the advantage that it is simple, and construction equipment, but the advantage of less expensive MPPT converter and production, including the energy stored in the battery charging circuit and battery for managing circuitry is required. The use of existing alternative energy in the form of combined-cycle power generation than the one adopted by the form, but primarily solar / wind power system to optimize complex to design and improve the ability to install a battery that canrationalize the price you need an integrated control system be.

• Journal of the Korean GEO-environmental Society
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• v.15 no.6
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• pp.75-83
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• 2014

Suction bucket foundation is installed with the differential pressure created by pumping water out of bucket. Bucket foundation has usually been utilized in mooring anchor for offshore platform or floating oil and gas production facilities in the open sea. After suction bucket foundation successfully was applied as the foundation for offshore wind turbines in Europe, it recently attracts much attention in Korea, too. To estimate the penetration resistance of the suction bucket foundation is one of the important matters that should be considered during its installation. This study carried out a series of model tests to investigate the penetration resistance of suction bucket foundation. And the mobilized soil strength factor was reviewed through comparing the experimental results by two installation ways (e.g., push-in-load and suction) and the results calculated by the conventional equation.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.367-374
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• 2023

As the Fourth Industrial Revolution accelerating, countries worldwide are developing technologies to digitize and automate various industrial sectors. Building smart factories not only reduces costs through improved process productivity but also allows for preemptive identification and removal of risk factors through the practice of Health, Safety, and Environment (HSE) management, thereby reducing industrial accident risks. In this study, we visualized pressure, temperature, power, and wind speed data measured in real-time via a monitoring GUI, enabling field managers and workers to easily access related information. Through the work environment monitoring system developed in this study, it is possible to conduct economic analysis on per-unit basis, based on the digitization of production management elements and the tracking of required resources. By implementing HSE in shipyards, potential risk factors can be improved, and gas and electrical leaks can be identified, which are expected to reduce production costs.