• Transactions of the Korean hydrogen and new energy society
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• v.22 no.6
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• pp.852-858
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• 2011

This paper is aiming to estimate the mutual influence of the stack cooling performances with the operation modes of the thermal management system for the hydrogen fuel cell vehicles. The heat capacity of the thermal management system was measured by varying the operating modes such as stack cooling heat exchanger only (Mode 1), stack cooling and electric devices cooling heat exchangers (Mode 2), and stack cooling and electric devices cooling heat exchangers with an operation of the condenser (Mode 3).As the results, Performance of the thermal management system (TMS) at Mode 3 decreased up to 34.0%, compared with the result of the Mode 1. In addition, in order to optimize the performance of TMS, the entropy change of stack cooling heat exchanger using irreversibility analysis technique was analyzed with the relationship between entropy generation and entering air velocity of the thermal management system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.659-677
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• 2022

Hydrogen is emerging as a next-generation energy source and development and supply of FCEV (hydrogen fuel cell electric vehicle) is expected to occur rapidly. Accordingly, measures to respond to hydrogen car accidents are required and researches on the safety of hydrogen cars are being actively conducted. In this study, In this study, we developed a hydrogen car accident scenarios suitable for domestic conditions for the safety evaluation of hydrogen car in road tunnels through analysis of existing experiments and research data and analyzed and presented the hazard distance according to the accident results of the hydrogen car accident scenarios. The accident results according to the hydrogen car accident scenario were classified into minor accidents, general fires, jet flames and explosions. The probability of occurrence of each accident results are predicted to be 93.06%, 1.83%, 2.25%, and 2.31%. In the case of applying the hydrogen tank specifications of FCEV developed in Korea, the hazard distance for explosion pressure (based on 16.5 kPa) is about 17.6 m, about 6 m for jet fire, up to 35 m for fireball in road tunnel with a standard cross section (72 m²).

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.3
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• pp.246-255
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• 2023

Due to lack of hydrogen charging stations and hydrogen supply compared to the supply of hydrogen vehicles, social phenomena such as 2-hour queues and restrictions on charging capacity are occurring, which negatively affects the spread of hydrogen vehicles. In order to resolve these problems, it is essential to have a strategic operation of the hydrogen charging stations. To establish operational strategies, it is necessary to derive customer demand patterns and characteristics through the analysis of sales data. This study derived the demand patterns and characteristics of customers visiting hydrogen charging stations through data analysis from various perspectives, such as charging volume, charging speed, number of visits, and correlation with external factors, based on the hydrogen sales data of off-site hydrogen charging stations located in domestic residential areas.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.9-19
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• 2010

Every car manufacturer desires to reduce the new car development time spent in improving the safety, NVH, lightweight, reliability and environment friendly features of the car. Other considerations such as planning, exterior and interior styling, packaging, color, and material selection increase the complexity of the car design process. This paper proposes a personal DDP (Digital Design Process) to utilize the engineering analysis and design/styling software for car design. DDP can be efficiently used by a team of car research center or a studio with small number of engineers, helping ordinary engineers becoming ambidextrous in design as well as engineering applications. The concept model starts from idea sketch, rendering, and 3D surface model with CAS (Computer Aided Styling) to the final safety estimation by using proposed DDP based on engineering technology (CAD, CAE). The concept model proposed a hydrogen fuel cell sports coupe which could be available within next 10 years. The proposed DDP can not only reduce the new car development time but also be adapted into designing of varied products such as aircraft, yacht, electrical equipment and sports gear.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.1
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• pp.64-72
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• 2009

In order to convert efficiently vibration energy of a car tire wheel into electrical power by using piezoelectric materials, the design of the materials must be performed for the dynamic characteristics of the piezoelectric materials to be matched with them of the vibration energy sources well. An accelerometer was installed on the tire wheel with a slip ring to investigate the dynamic mode of the wheel as one of the vibration energy sources. During road test, the measurement on the vibration mode of the tire wheel was performed with variations of car speed and road condition. The experimental data were analyzed details for availability as a micro power source for wireless TPMS(Tire Pressure Monitoring System).

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.731-732
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• 2022

최근 탄소중립을 위한 친환경 자동차 권장 정책으로 인해서 전기차와 수소차 이용자가 증가하고 있다. 그러나 기존 내연기관차, 또는 전기차와 비교했을 때 수소차에 대한 인프라는 매우 부족한 현실이다. 따라서 출장이나 여행 등 기존 주거지를 벗어나는 상황에서는 수소차 충전소를 찾는데 어려움을 겪을 수 있다. 본 논문에서는 수소차 이용자들에게 편의를 제공하기 위해서 전국의 수소차 충전소의 위치를 구글 지도에서 보여주고 충전소의 사진과 전화번호를 쉽게 확인할 수 있는 애플리케이션을 설계 및 구현하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.642-648
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• 2017

The use of fossil is causing enviromental all over the world. So hydrogen energy is attracting attention as one of the alternative. The government announced that 30% of the air pollution is because of the Internal Combustion Engine Vehicle. In addition, they plans to reduce Internal Combustion Engine Vehicles by 2030 and increase (electric vehicles, EV) or (fuel cell vehicle, FCV). The FCV is evaluated as a next-generation green car because it has a long driving distance and short charging time. However, the hydrogen industry is not able to expand due to the lack of refueling infrastrucutre. This paper predicts the site of hydrogen refueling stations for the expansion of the hydrogen industry and proposes a method to supply hydrogen multi energy filling stations.

• Corrosion Science and Technology
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• v.17 no.4
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• pp.193-201
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• 2018

In order to suppress $CO_2$ emission and protect passengers in case of vehicle collision, continuous efforts are being made to increase the application ratio and tensile strength of advanced high strength steels used in the manufacturing of automotive body. Simultaneously, hydrogen embrittlement which was not a concern in the past has currently become a major issue due to microstructure that is sensitive to hydrogen uptake. The sensitivity increases with residual stress and hydrogen uptake content. Many automotive OEM companies and mill makers are setting specifications to control hydrogen embrittlement. The factors which lead to hydrogen embrittlement are material sensitivity, residual stress, and hydrogen concentration; researches are in progress to develop countermeasures. To reduce material sensitivity, mill makers add high energy trap elements or microstructure refinement elements. Automotive OEM companies design the car parts not to concentrate local stress. And they manage the levels to not to exceed critical hydrogen concentration. In this article, we have reviewed hydrogen embrittlement evaluation methods and corresponding solutions that are being studied in automobile manufacturing industries and mill makers.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.1
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• pp.32-40
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• 2018

There has been an measuring errors between state of charge (SOC; kg) value and mass flow meter (MFM) value in dispenser for hydrogen refueling station. Finally, we observed average 15.5% weight difference between these two values and the MFM readings show a 15.5% higher readout of the SOC readings. Each car was charged with average 2.66 kg of hydrogen fuel during this period. In the initial charging of the day shows less measuring value than the final charging with the maximum 0.038 kg times number of filling. There is no effects of atmosphere temperature change for the hydrogen filled weight during one full year such as January's cold winters and August's hot summers.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.465-470
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• 2010

Korea government declared that "low carbon, green growth" through green technologies and clean energy to be the new national vision for the next 60 years(President's Liberation Day speech on Aug. 15, 2008). And succeeding "Green New Deal" plan involves nine core projects including energy saving, recycling, clean energy development. It is because hydrogen fuel cell vehicles, using electricity from chemical reaction of hydrogen and oxygen, let out water which is a by-product of such chemical reaction instead of emitting harmful particulate and gases such as NOX, SOX and CO2 that hydrogen fuel cell vehicles and its technology are drawing public attention as one of the sensible solutions in accomplishing "low carbon, green growth" agenda. Nevertheless There are many chances that let the people have a practical experience of hydrogen fuel cell vehicles. Sometimes new products, including hydrogen fuel cell vehicles, made by advanced technology can not penetrate through the market when it faces public skepticism that is stimulated from lack of knowledge and experience. That is the reason why not only cost benefit analyses and scientific risk assessments but also public acceptance studies toward hydrogen fuel cell vehicles have to be performed [Schulte, 2004]. This research address a need for comprehensive study on factors influencing public acceptance of hydrogen fuel cell car, specifically focusing on impacts of personal experience related to governmental science and technology policy toward public acceptance.