• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.223-230
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• 2011

According to EMEP/EEA Emission Inventory Guidebook, the emissions produced by vehicle in cold start phase should be calculated differently compared to hot start phase. In this study, considering this driving cycle, more appropriate procedures for estimating Environmental Benefits was suggested. Using Tier 3 standard, all links within the impact area were included in estimating emissions. Traffic volume and travel distance were analyzed using EMME/3 software. For application of the procedures in this study, the case study was carried out with real transportation project. As a result, the Environment-Benefits increased by 30%. If the methodology suggested in this study is applied to feasibility study it will help to activate the investment of the environment-friendly modes like railway in the future.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.233-234
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• 2002

도시대기오염의 주요 배출원으로 알려진 자동차에서 배출되는 VOCs는 인체에 유해할 뿐만 아니라 대기 중에서 질소산화물(NOx)과 함에 광화학반응을 통한 오존 둥 2차 오염물질인 광화학산화물을 형성하는 전구물질로 작용하기 때문에 환경학적, 보건학적으로 매우 큰 영향을 미친다. 이러한 자동차 배출 VOCs가 오존생성에 미치는 영향에 대한 연구는 갈수록 증가하고 있는 대기중 오존 농도 심화현상의 규명과 대기질 개선을 위한 기초자료로서 매우 그 필요성이 더해가고 있다. (중략)

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.919-922
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• 2004

The Field Emission Display is potentially an excellent display with high brightness and low power consumption with wide viewing angle but more work is still needed in order to identify the ideal electron emitter for such displays. This paper will review the work that we have carried out in Cambridge aver the past couple of years on optimisation of Carbon nanotubes for use as the cold cathode emitters that are possible candidates as the electron sources in second generation FEDs.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.722-726
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• 2003

본 논문에서는 Porous poly-silicon cold cathode에 의해 전자를 방출하는 Ballistic electron surface-emitting display(BSD)의 전계방출 특성을 실험했다. BSD는 nanocrystalline을 둘러싼 산화막을 multi-tunneling한 전자에 의해 발광이 되는 mechanism이기 때문에 산화막의 두께를 변수로 두어 특성을 실험했다. 900℃에서 1시간에서 3시간까지 30분 간격으로산화 반응을 진행하였으며, leakage current와 emission current의 비로 효율을 나타내었을 때 1시간 30분 동안 산화 반응을 한 시료가 가장 좋은 특성을 나타내었다.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3317-3322
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• 2007

THC(Total Hydrocarbon) emissions during cold start and warm-up phase constitute the majority of THC emissions during the FTP-75 mode. As the basic approach to improve the emission performance of Gasoline engine during transient phase, the effect of spark timing retard from MBT on THC emission characteristics is studied by engine test using a Fast response Flame Ionization Detector(FFID). A cyclic analysis of the combustion process shows that high THC emissions are produced first few cycles during the transient phase. This paper presents the results of engine performance and emission of Gasoline engine with various spark timing. consequently, This paper was focused on the combustion phenomena with various spark timing during transient phase which was analyzed by Fast response Flame Ionization Detector (FFID) equipment to measure the cyclic THC emission characteristics.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.448-454
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• 2001

Low field electron emission from novel carbon based cold cathodes is reported. The cathodes consisted of a layer of nanoseeded diamond and an over layer of nanocluster carbon films. The nanoseeded diamond was first coated on to thesubstrate. The nanocluster carbon films were then deposited on the nanocrystalline diamond coated substrates using the cathodic arc process at room temperature. The heterostructured microcathodes were observed to exhibit electron emission currents of 1 $\mu$A/cm$^2$ at fields as low as 1.5 to 2V/$\mu$m. The effect of the nanoseeded diamond size and concentration and the properties of different nanocluster carbon films on emission characteristics is presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.104-112
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• 1999

An experimental study for reducing the exhaust hydrocarbon emission at spark ignition engine using timed secondary air injection is carried out . In this study, secondary air injection timings and durations are controlled to decrease the hydrocarbon emission and to increase exhaust gas temperature at cold and warm-up engine conditions. The hydrocarbon reduction rate and exhaust gas temperature are compared between timed secondary air injection and continuous air injection. The optimum secondary air injection timing for reducing the hydrocarbon emission is at the exhaust valve open timing. At some engine conditions , the hydrocarbon emissions are decreased to 10% of engine raw values and exhaust gas temperatures increase by 20$0^{\circ}C$ with times secondary air injection . Timed secondary air injection has more hydrocarbon reduction rate that continuous secondary air injection except some engine conditions.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.5
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• pp.89-94
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• 1991

In the quantitative analysis of oxygenated exhaust emissions (unburned methanol, formal- dehyde) from methanol fueled vehicles, the oxygen contained in oxygenated exhaust gases lowers the FID (Flame Ionization Detector) response factor of conventional THC analyzer and leads to erroneous HC reading. For correct measurement of various HCs including oxygenated HCs emitted from FFV(Flexible Fuel Vehicle), first of all, the measurement technique of real HC emissions should be established. GC and HPLC-DNPH measuring methods specified by the EPA are used in this paper to analyze unburned methanol and formaldehyde components in the exhaust emissions. In emission test of FFV, unburned methanol and formaldehyde are emitted mostly during cold transient period, and it is shown that formaldehyde emission level is proportional to engine displacements. In view of the HC emission level, vehicle using M85 has 40% advantage over gasoline-fueled vehicle in OMHCE and has a good potential of a low emission vehicle.

• Applied Microscopy
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• v.46 no.4
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• pp.244-252
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• 2016

This paper describes a new design of carbon nanotube tip. $Nanocly^{TM}$ NC 7000 Thin Multiwall Carbon Nanotubes of carbon purity (90%) and average diameter tube 9.5 nm with a high aspect-ratio (>150) were used. These tips were manufactured by employing a drawing technique using a glass puller. The glass microemitters with internal carbon nanotubes show a switch-on effect to a high current level (1 to $20{\mu}A$). A field electron microscope with a tip (cathode)-screen (anode) separation at ~10 mm was used to characterize the electron emitters. The system was evacuated down to a base pressure of ${\sim}10^{-9}$ mbar when baked at up to ${\sim}200^{\circ}C$ overnight. This allowed measurements of typical Field Electron Emission characteristics; namely the current-voltage (I-V) characteristics and the emission images on a conductive phosphorus screen (the anode). Fowler-Nordheim plots of the current-voltage characteristics show current switch-on for each of these emitters.

• International Journal of Automotive Technology
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• v.7 no.3
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• pp.277-282
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• 2006

With the aim of achieving half the regulated value of EURO-3 Emission Regulations, an ultra low emission motorcycle has been developed based on a motorcycle with an 1800 $cm^3$, horizontal opposed 6-cylinder engine. For the fuel supply system, an electronically controlled fuel injection system was applied. For the emission purification system, three-way catalysts, a feedback control system with a LAF(Linear Air-Fuel ratio) sensor, and a secondary air induction system were applied. To reduce CO and HC emissions during cold starting, an early catalyst activation method combining RACV(Rotary Air Control Valve) and retarded ignition timing was applied. After the catalyst activation, air-fuel ratio was controlled to maximize the purification ratio of the catalyst according to vehicle speed. For the air-fuel ratio control system, the LAF sensor was used. Furthermore, fine adjustment by the LAF feedback control reduced torque fluctuation due to the air-fuel ratio change. As a result, smooth ride feeling was maintained. Owing to these technologies, half the regulated value of EURO-3 has been achieved without any negative impact to the large-scaled motorcycles' drivability. This paper presents the developed ultra low emission technologies including the control method using an LAF sensor.