• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.636-639
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• 2007

We have developed novel bipolar host materials, designed to have both electron transporting and hole transporting abilities, which show significant increase in luminance efficiency and decrease in driving voltage of green phosphorescent OLEDs. In case of the best host material, CheilGH-3, the driving voltage was decreased 27 % at a given constant luminance of $1000cd/m^2$. Also the luminance efficiency was enhanced 44 % and the power efficiency was almost doubled compared to the reference device using CBP as a host.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.4
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• pp.397-402
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• 2023

We have developed inverted green phosphorescent organic light emitting diodes (OLEDs) using 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) and bis(carbazole-9-yl)biphenyl (CBP) hole transport layers. The driving voltage, current efficiency, power efficiency, and emission characteristics of devices were investigated. While the driving voltage for the same current density was about 1~2 V lower in the devices with the TAPC layer, the maximum luminance was higher in the device with the CBP layer. The maximum current efficiency and power efficiency were 3.2 and 2.7 times higher in the device with the CBP layer, respectively. The higher efficiency in the CBP device resulted from the enhanced hole-electron balance although weak parasitic recombination takes place in the CBP hole transport layer.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.191-206
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• 2018

In this study, the HAPs(Harzard Air Pollutants) emission factor level of Starex and Grand Carnival was tested using PEMS (Portable Emissions Measurement System) on real road driving. As a result of RDE (Real Driving Emission test), the overall vehicle speed pattern showed similar characteristics. The real-road driving test at constant speed revealed emission factor is inversely proportional relationship to constant speed. Results of accelerating with speed limit on the real-road were shown as followings; Uran (less than 45 km/h)>Rural (<45 km/h, less than 80 km/h)>Motorway (>80 km/h). Moreover, the sudden acceleration and deceleration in driving at high speed was the increasing factor to the HAPs emission factor. This tendency is considered to be influenced by the operating environment on real roads.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.30-33
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• 2008

Using a $Ir(ppy)_3$ doped in hole and electron transport host materials, simple three layers green PHOLEDs comprising double emissive layers have been fabricated. A low driving voltage value of 3.3 V to reach a luminance of $1000\;cd/m^2$ and maximum current- and power-efficiency values of 53.9 cd/A and 57.8 lm/W are demonstrated in this simple structure phosphorescent OLED.

• Journal of the Korean Ceramic Society
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• v.45 no.10
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• pp.625-630
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• 2008

In the bone cement composed of dense granules of $\beta-Ca_3(PO_4){_2}(\beta-TCP)$ and $Ca(H_2PO_4){_2}H_2O$, the compressive strength, setting time and temperature rise were measured to observe the degradation of cement with respect to the stored days before setting. Decreases of compressive strength and temperature rise were observed, while setting time increased with respect to the stored days. The similar trends were repeated with the increase of temperature of storage. Such a change virtually meant the fading of the character of cement and it took place only when the two starting materials were mixed during storage. The degradation could be mitigated taking advantage of granular $\beta$-TCP instead of powdery one. The formation of $CaHPO_4$, which resulted from reaction with ambient humidity, was attributed to the degradation observed during storage. Dependence of the degradation behavior on mixing and temperature during storage was discussed in terms of the driving force for reaction of cement.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.3
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• pp.162-165
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• 2012

In this paper, the method of controlling velocity between joining vehicles at the point of bottleneck using information and communications technology of WAVE method based V2V and V2I are proposed for the driving with high fuel efficiency. Using the derived fuel-efficiency comparative analysis model, it was shown that the proposed method's fuel efficiency is better than traffic light method demanding periodically vehicle's stop. Also, this method provides the derivation algorithm for deceleration and acceleration for controlling velocity between vehicles approaching bottleneck area.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.10
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• pp.269-283
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• 2021

The government policies and initiatives to guarantee sustainable energy and clean environmental conditions contributed to the introduction of green technology electricity appliances in the market. This study sought to determine the physiological and socio-economics-demographic factors driving residential electricity consumers to use green technology electricity appliances, mainly solar PV, smart meter, electric vehicle, and battery storage technology. By understanding consumer intention, the investors of solar PV, battery storage, electric vehicle, and smart meter can estimate the demand and upscale the market for the corresponding products. For that purpose, the intention to use the solar PV, smart meter, electric vehicle, and battery storage function is developed by utilizing the combination of the theory of planned behavior, technology acceptance, and reasoning action. A reliable and valid structured online questionnaire and stepwise multiple regression are used to identify the possible factors that drive consumer behavior intention. The results show that the social influence, knowledge on RE, and perceived price significantly influence residential consumers' willingness to adopt the technologies offered. The findings of this study suggest that the involvement of NGOs, public figures, and citizens' cooperation are all necessary to spread information about the government's objectives and support Malaysia's present energy and environmental policies.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.283-283
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• 2009

Composition environments - Automatic Control System based on Sproute Cultivator using Remote Conditional Driving System was realized. It was carried out to investigate into the characteristics of LEDs Control for the cultivation of sprouts. We have also composed a Combined Automatic Control System possible for the control of temperature and humidity at the same time. The applied LEDs for measurement are blue, green, red, white, yellow leds. And we had also designed the Web Programming for the automatic control about sprout cutivators.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.1
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• pp.35-42
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• 2013

This paper shows the positivistic approach for analyzing the effect of ICT on the reduction of greenhouse gas (GHG) emission. The real-time navigation was selected for the ICT based service in this research, and the CO2 reduction ratios of the optimized routes in the navigation were compared with the reduction ratios of the shortest routes in existing navigations. The results of experiments showed the driving based on the optimized routes has more reduction effects than the driving on the basis of the shortest routes. Also, new evaluation method for GHG emission was suggested by the quantification and monitoring approaches on the basis of the Clean Development Mechanism (CDM) in this paper. The results of this paper can be used as a preliminary research for the effect of ICT on the reduction of GHG emission. The evaluation method which suggested in this paper will be suggested to CDM as the new standard for the reduction of GHG emission in the transportation field as well.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.95-105
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• 2012

The selective catalytic reduction (SCR) system is a highly-effective aftertreatment device for NOx reduction of diesel engines. Generally, the ammonia ($NH_3$) was generated from reaction mechanism of SCR in the SCR system using the liquid urea as the reluctant. Therefore, the precise urea dosing control is a very important key for NOx and $NH_3$ slip reduction in the SCR system. This paper investigated NOx and $NH_3$ emission characteristics of urea-SCR dosing system based on model-based control algorithm in order to reduce NOx. In the map-based control algorithm, target amount of urea solution was determined by mass flow rate of exhaust gas obtained from engine rpm, torque and $O_2$ for feed-back control NOx concentration should be measured by NOx sensor. Moreover, this algorithm can not estimate $NH_3$ absorbed on the catalyst. Hence, the urea injection can be too rich or too lean. In this study, the model-based control algorithm was developed and evaluated on the numerical model describing physical and chemical phenomena in SCR system. One channel thermo-fluid model coupled with finely tuned chemical reaction model was applied to this control algorithm. The vehicle test was carried out by using map-based and model-based control algorithms in the NEDC mode in order to evaluate the performance of the model based control algorithm.