• Membrane Journal
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• v.26 no.2
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• pp.141-145
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• 2016

Polymer electrolyte membranes (PEMs) are key components to determine electrochemical fuel cell performances, in addition to electrode materials. The PEMs need to satisfy selective transport behaviors to small molecules including gases and protons; the PEMs have to transport protons as fast as possible, while they should act as hydrogen barriers, since the permeated gas induces the thermal degradation of cathode catalyst, resulting in rapid electrochemical reduction. To date, limited tools have been used to measure how fast hydrogen gas permeates through PEMs (e.g., Constant volume/variable Pressure (time-lag) method). However, most of the measurements are conducted under vacuum where PEMs are fully dried. Otherwise, the obtained hydrogen permeance is easily changeable, which causes the measurement errors to be large. In this study, hydrogen permeation properties through Nafion212 used as a standard PEM are evaluated using an in-situ measurement system in which both temperature and humidity are controlled at the same time.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.605-608
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• 2017

최근에는 의료기기의 구성 요소 중 소프트웨어의 기능과 역할이 커지면서 의료기기 소프트웨어의 비중이 높아지고, 의료기기의 사용자의 생명과 안전에 직결되는 특성으로 인해 의료기기 소프트웨어 위험관리의 중요성은 더욱 강조되고 있다. 이를 위해 여러 표준들은 위험관리를 위한 다양한 요구사항들을 제시한다. 그러나 의료기기 소프트웨어 개발생명주기의 각 단계에서 수행되어야하는 위험관리 항목들은 분류되어있지 않다. 이로 인해 개발자들은 의료기기 개발 중에 직접 표준들의 연관성을 분석하여 위험관리 활동을 수행해야하는 어려움을 겪고 있다. 따라서 본 논문에서는 위험관리 프로세스의 항목들을 추출하고 PEMS(Programmable Electrical Medical System) 개발생명주기와 대응시켜 연관성을 분석하고, 이를 통해 의료기기 소프트웨어의 개발 중 효과적이고 체계적인 위험관리를 가능하게 한다.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.67-70
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• 2014

Recently EU has been recognized that there is a difference of emission quantity between emission certification test mode and real-road driving test. Accordingly the European Commission is currently preparing to require real-road testing as part of the passenger car type-approval process in the EU. vehicle manufacturers from 2017 are expected to test new vehicles not only under laboratory conditions but also on the real-road, using PEMS equipment. Therefore the purpose of this study is to analyze the emission and Fuel Economy of CVS-75 mode test using chassis dynamometer and RDE test using PEMS equipment by PHEV passenger car.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.271-271
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• 2006

The present article describes a novel method of preparing the sulfonated polysulfone-based PEMs for DMFC, which are excellent in film quality, proton conductivity, methanol impermeability and mechanical properties. No depression in film quality or difficulty in film preparation is observed, even though sulfonated group of the PEMs are kept as high as 70 mol %. Allyl-terminated cooligo-PESs containing the organic sulfonate groups were solvent-cast into films and then thermally treated for cross-linking. Cross-linked sulfonated polysulfone-based PEMs gave unprecedented reduction of methanol cross-over and high ionic conductivity through in-situ thermal polymerization and cross-linking of telechelic sulfonated sulfone oligomers during a membrane preparation.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1087-1090
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• 2008

This paper presents the electro-luminescence (EL) display lamp which is patterned on a curved surface by the pad printing method. The printing methods, including the gravure, screen, flexo, inkjet, and pad printing, have an advantage of one-step direct patterning. However, in general, the printing and semi-conductor process, except pad printing method, cannot be applied for patterning on a curved surface. Thus, in this paper, we used pad printing method for patterning an EL display lamp on a curved surface. The EL display lamp consists of 5 layers: Bottom electrode; Dielectric layer; Phosphor; Transparent electrode; Bus electrode. Finally, we printed EL display lamp on a dish, which has a radius of curvature 80mm. The EL display lamp was driven at AC 200V of 1kHz.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1063-1069
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• 2022

According to domestic air pollutant emission statistics, a considerable amount of air pollutants is generated by ships. Therefore, various policies are being implemented to limit air pollutant emissions from ships and improve the air quality in ports. In addition, international conventions are carried out for the prevention of marine pollution by ships. However, because few studies and experiments have been conducted on the measurement of air pollutants emitted from actually operating ships, this study presented a method and possibility for evaluating air pollutant emissions from a 9,196GT ship actually operating using a portable emission measurement system (PEMS). A difference in emission occurred depending on the RPM and load, and the emission of NO_X was 497-2,060ppm, CO₂ was 1.55-6.9%, and CO was 0.002-0.14%. The emission specified in the shop test provided by the engine manufacturer differed from the actual emission measured. This study proved that the maximum emission of each air pollutant generated in the entire sailing section of the ship was included in the PEMS measurement range, and the possibility of using PEMS for ships within 10,000GT was verified.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.454-462
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• 2016

This study was conducted in order to estimate the exhaust emissions analysis method of the real driving emission(RDE). The Association for Emissions Control by Catalyst(AECC) has developed a test procedure by using a random cycle method based on the chassis dynamometer. In order to confirm this approach in Korea, Euro 5(DPF), Euro 6(DPF + LNT), and Euro 6(DPF + SCR) were performed on three different vehicles to determine the exhaust gas characteristics of the random cycle, real-road driving test(PEMS), and emission certification driving mode(NEDC). Six different random cycle driving modes were generated by the vehicle specifications(e.g. curb weight, engine power, gear ratio, and maximum acceleration). The NOx emissions were increased in the NEDC, random cycle, and PEMS order in this study regardless of the test vehicles. The random cycle method has the advantage because it utilizes a chassis dynamometer in the laboratories for a repeatable data collection, and it allows any eminent emission improvement checked prior to a real-road driving test with PEMS.

• Journal of Digital Convergence
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• v.17 no.9
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• pp.147-152
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• 2019

Infrastructure is rapidly growing as Internet business grows with the latest IT technologies such as IoT, BigData, and AI. However, in most companies, a limited number of people need to manage a lot of hardware and software. Therefore, Polestar Enterprise Management System(PEMS) is applied to monitor the system operation status, IT service and key KPI monitoring. Real-time monitor screening prevents system malfunctions and quick response. With PEMS, you can see configuration information related to IT hardware and software at a glance, and monitor performance throughout the entire end-to-end period to see when problems occur in real time.

• Journal of ILASS-Korea
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• v.21 no.4
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• pp.200-206
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• 2016

Recently, the certification procedure for exhaust emission regulation of LDV has tested with the NEDC mode in the laboratory. But the on-road exhaust emissions exceed the standard emission limits. Therefore, it is important to analyze the real-driving emissions (RDE) with a portable emissions measurement system (PEMS). In present study, the on-road emissions were measured with a PEMS and evaluated by moving averaging window (MAW) method. Also, it was compared with the $CO_2$ and $NO_x$ emissions for real-driving and test modes from euro-6 light-duty vehicles equipped with SCR and LNT systems. In results, on-road $NO_x$ emission has been 2.3-10.0 times higher than the standard $NO_x$ emission limit on NEDC mode. The reason was that the test modes did not reflect traffic and various real-driving patterns sufficiently.

• Journal of the Korean Institute of Gas
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• v.14 no.2
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• pp.47-52
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• 2010

The development of energy saving system with pressure regulator has recently been received interests. Since the internal geometry in the pressure regulator is small and complex, the frictional loss in it is critical. In this study, the pressure loss with tip size, tip position, and mass flow was investigated using numerical approaches(CFD). The aimed reduction in pressure were achieved as the ratio of t/T was more than 0.8. In addition, there was no effect of the tip position.