• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1185-1192
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• 2012

The typical operating temperature of an automotive fuel cell is lower than that of an internal combustion engine, which necessitates a refined strategy for thermal management. In particular, the performance of the cooling module has to be higher for a fuel cell system because the temperature difference between the fuel cell and the surrounding is lower than in the case of the internal combustion engine. Even though the cooling system of an automotive fuel cell determines the operating temperature and temperature distribution of the fuel cell, it has attracted little research attention. This study presents the mathematical model of a cooling system for an automotive fuel cell system using Matlab/$Simulink^{(R)}$. In particular, a radiator model is developed for design optimization from the development stage to the operating stage for an automotive fuel cell. The cooling system model comprises a fan, pump, and radiator. The pump and fan model have an empirical relation, and the dynamics of the pump and fan are only explained by motor dynamics. The basic design study was conducted, and the geometric setup of the radiator was investigated. When the control logic was applied, the pump senses the coolant inlet temperature and the fan senses the coolant out temperature. Additionally, the cooling module is integrated with the fuel cell system model so that the performance of the cooling module can be investigated under realistic operating conditions.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.44 no.11
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• pp.50-55
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• 2015

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.75-76
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• 2016

최근 들어 차량용 블랙박스의 급속한 보급으로 많은 분야에서 중요하게 사용되고 있다. 그러나 현재의 차량용 블랙박스 시스템은 제한된 메모리의 용량에 영상 파일을 저장하기 위해, 일정 용량이 저장되면 먼저 저장된 영상 파일을 순차적으로 삭제하여 새로운 영상 파일이 저장되도록 설계되어 있다. 이것은 장시간 주차 중에 발생할 수 있는 차량훼손을 분석하기 위해서는 제약사항이 아닐 수 없다. 이러한 문제점을 해결하기 위해서 본 논문에서는 FTP를 이용하여 주행 중 혹은 주차 중의 영상 파일을 삭제 없이 지속적으로 저장할 수 있는 시스템을 제안한다. 제안한 시스템은 차량용 블랙박스 뿐 아니라 제한된 용량에 영상 파일을 저장하는 수많은 시스템에 동시 적용할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.1
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• pp.39-45
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• 2016

Thermal management of a fuel cell is important to satisfy the requirements of durability and efficiency under varying load conditions. In this study, a linear state feedback controller was designed to maintain the temperature within operating conditions. Due to the nonlinearity of automotive fuel cell system, the state feedback controller results in marginal stable under load condition from $0.5A/cm^2$ to $0.7A/cm^2$. A PWM (Pulse Width Modulation) and the modified state feedback controller are applied to control the temperature under the load condition from $0.5A/cm^2$ to $0.7A/cm^2$. The cooling system model is composed of a reservoir, radiator, bypass valve, fan, and a water pump. The performance of the control algorithm was evaluated in terms of the integral time weighted absolute error (ITAE). Additionally, MATLAB/SIMULINK$^{(R)}$ was used for the development of the system models and controllers. The modified state feedback controller was found to be more effective for controlling temperature than other algorithms when tested under low load conditions.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.425-428
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• 2005

본 연구는 건설장비 차량 조립부품을 제작하는 가공공장의 계획 및 운영 시스템 개발에 대한 내용이다. 연구의 대상은 건설장비 차량인 굴삭기, 휠로더, 지게차의 조립부품을 제작하는 공장으로 제작품별 제작라인이 구성되어 있다. 그리고 각 제작라인에는 여러 개의 공정이 있으며, 일부 공정은 작업자에 의해 작업이 이루어지고, 용접 및 가공 등은 자동화된 장비 및 설비에 의해 작업이 된다. 가공공장에서 관리 및 운영의 주요 관점은 이후 공정인 조립공장의 조립 착수일에 늦지 않게 제작된 부품을 공급하는 것이다. 그리고 공장 자체적으로 제작라인 내의 재공재고 감소, 작업일간 작업부하평준화, 자동화 장비 및 설비의 효율 극대화 등이 공장의 주요 관리 사항이다. 따라서 본 연구에서는 가공공장에서 제작되는 조립부품의 납기일 준수, 재고 감소, 부하 평준화, 장비효율의 극대화를 위해 공장을 체계적으로 관리하기 위한 계획 및 운영 시스템을 개발하였다. 개발시스템에는 제작라인별 제작 착수 및 자재발주${\cdot}$입고 관리, 공정별 실적관리, 실시간 작업 진행 관리, 용접 불량 관리 기능 등이 있다. 시스템은 MSSQL 서버, 오라클과 Visual Basic, Visual C# ASP로 개발되었다.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.345-348
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• 2008

The computer-aided performance simulation can reduce periods for development of products and cut down on the cost comparing with former trial-and-error procedures. This study has developed a simulation program for a vehicle thermal management system integrating an engine cooling system and an air conditioning system considering interactions and arrangement of air side heat exchangers such as power steering oil cooler, air-cooled transmission oil cooler, condenser, and radiator. The program may be also used for the system performance analysis according to the configuration of the engine coolant side heat exchangers such as water-cooled transmission oil cooler, EGR cooler, and heater core. Experiments utilizing an environmental wind tunnel has been conducted to assess the performance of the system according to the arrangement of air side heat exchangers. Some modification of the coolant loop layout can enhance the heat core performance up to 7% according to the results of the simulations.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.169-176
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• 2022

With the continuous development of technologies related to 5G, artificial intelligence, and autonomous vehicle systems, standards and services for V2X and C-ITS environments are being studied a lot. BSM (basic safety message) was adopted as a standard for exchanging data between vehicles based on data collected and generated by vehicle systems in a V2V environment. In this paper, we propose a framework that can safely store BSM messages and effectively check the stored messages using Event-Sourcing and CQRS patterns. The proposed framework can securely store and manage BSM messages using hash functions. And it has the advantage of being able to check the stored BSM data in real time based on the time series and to reproduce the state.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.297-308
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• 2017

One of the major engine thermal management system(TMS) strategies for improving fuel economy is to operate the engine in high temperatures. Therefore, this work performed a numerical and experimental study to examine the effect of several different STOs(Starting Temperature of Opening) of wax-thermostat, ranging from $85^{\circ}C$ to $105^{\circ}C$, of gasoline engine on fuel economy and emission characteristics. In this study, a gasoline car equipped with waxthermostat was tested and simulated under FTP-75 and HWFET mode. CRUISE $M^{TM}$ was used to simulate vehicle dynamics, transient engine performance and TMS. The test results showed fuel savings for both drive cycles due to higher STO of $100^{\circ}C$, which is slightly worse than that of $90^{\circ}C$ and amounts between 0.34 and 0.475 %. These controversial results are attributed to experimental errors and uncertainty. The computational results for three STOs, $85^{\circ}C$, $95^{\circ}C$ and $105^{\circ}C$, showed that fuel savings attributed to the application of higher STOs of $95^{\circ}C$ and $105^{\circ}C$ are relatively small and range from 0.306 to 0.363 %. It is also found that the amount of HC and CO emissions from the tailpipe tends to decrease with higher engine coolant temperature because of faster catalyst light-off and improved combustion.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.125-130
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• 2024

With the rapid growth of mobility technology, the industrial sector is demanding storage devices that can reliably process data from various equipment and sensors in vehicles. NAND flash memory is being utilized as a storage device in mobility environments because it has the advantages of low power and fast data processing speed as well as strong external shock resistance. However, flash memory is characterized by data corruption due to long-term exposure to high temperatures. Therefore, a dedicated system for temperature management is required in mobility environments where high temperature exposure due to weather or external heat sources such as solar radiation is frequent. This paper designs a dedicated temperature management system for managing storage device temperature in a mobility environment. The designed temperature management system is a hybrid of traditional air cooling and water cooling technologies. The cooling method is designed to operate adaptively according to the temperature of the storage device, and it is designed not to operate when the temperature step is low to improve energy efficiency. Finally, experiments were conducted to analyze the temperature difference between each cooling method and different heat dissipation materials, proving that the temperature management policy is effective in maintaining performance.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.14-24
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• 2006

There are many problems and limits in equipments being used for traffic-volume analysis in the country. And traffic-volume information acquired through existing equipments is not provided in real-time. In the case of urban, there are limits on guarantee of trust on comprehending a appropriate road-volume because of difficulty on analyzing traffic-volume density and time series. And it is difficult to applicate in deciding a road policy as existing equipments don't provide the control information of traffic-flow. Therefore, it is necessary to build a road-flow policy rapidly and accurately through the road-flow information that analyze post-processed statistics data using traffic-flow investigation based on real time. In this study, we developed TICS(Traffic Information Collection System) based on GPS which could transmit traffic information transformed from car location information to traffic control center. And we developed TCS(Traffic Control System) based on Web GIS, which could manage and analyze transmitted traffic information, and it could offer handled road-flow information to Web-site in realtime.