• Journal of Korean Society of Transportation
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• v.34 no.2
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• pp.135-145
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• 2016

This study assumes a vehicle choice model based on the multinomial model and analyzes the vehicle choice behaviors of consumer. An SP survey targeting drivers was implemented and data was collected for model estimates, with the possible choice options of the survey takers limited to gasoline, HEV, PHEV, and EV vehicles. The explanatory variable mostly displayed a significance level of under 5%, and excluding variables for price and fuel the remaining variables were all consistent with the logical direction with the plus (+) sign and the results were determined to be rational. Consumers selecting mid-size & full-size vehicles are able to afford more than consumers that selected other vehicle types, so there was relatively little consideration given to low fuel costs when compared to vehicle price. For this reason, it was determined that for the full-size vehicle model the fuel variable could be disregarded. Socio-economic variables that were statistically significant were the age and infor variables for the sub-compact & compact, the age, infor and inc3 variables for the mid-sized & full-size vehicles.

• Journal of Energy Engineering
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• v.13 no.2
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• pp.161-165
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• 2004

Evaporative emissions from gasoline powered vehicles continue to be a major concern. The performance of carbon canister in evaporative emission control systems has become an important aspect of overall fuel system development and design. A vehicle's evaporative emission control system is continuously working, even when the vehicle is not running, due to generation of vapors from the fuel tank during ambient temperature variations. In this study, the effects of evaporative emissions on the engine performance were investigated. The experimental results show the effectiveness of this system for future exhaust emissions and enhanced evaporative emissions. This paper discusses the evaluation on the relationship between carbon canister condition and engine performance while engine is running.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.341-346
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• 2014

Intake E-CVVT noise, generally caused by collision sound of roller and cage clearance at idle and driving condition, is considerable source of annoyance in passenger cars using the gasoline engine. Main source of this noise is the cam torque variation of an intake E-CVVT system, and can be controlled by clearance decrease such as backlash reduction, but which may increase the manufacturing cost. Thus in this paper, most effective solution for low noise intake E-CVVT was achieved through not only reduction of backlash and cam angular acceleration but also improvement of vehicle transfer system, which is optimal configuration through acoustic sensitivity optimization of engine mount support bracket.

• Environmental Analysis Health and Toxicology
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• v.13 no.1_2
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• pp.27-31
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• 1998

Motor vehicle exhaust is the major cause to the air contamination in Seoul. It includes many toxic chemicals to human health such as aidehyde, PAHs, benzene, xylene, toluene, benzo[a]pyrene, nickel, arsenic and cadmium in gasoline exhaust and formaldehyde, PAHs, 1,3-butadiene, benzene and particulate matter in diesel exhaust. Some chemicals out of them are classified as a human carcinogen. Many large diesel vehicles such as buses and trucks are drivened frequently in Seoul so that the air in Seoul is seriously contaminated by diesel exhaust, especially particulate matter. The amounts of particulate matter from large diesel vehicles may be estimated to be more than 50% of small dust in Seoul. The particles of particulate matter are coated with many toxic chemicals and some of these are considered as a human carcinogen. The cancer risk has to be throughly managed because the population density of Seoul is very high. Government should list hazardous air pollutants in Seoul, assess the exposure of people to toxic pollutants, especially carcinogens and manage human health risk.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2157-2162
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• 2004

As the friction between two mated materials generates electrostatic voltage, vehicles especially in the cold climate has been accumulated an electrostatic voltage by the reason of fuel flow in the fuel line, air flows out side of vehicle, etc. In this study, investigations of electrostatic discharge characteristics has been carried out in the fuel systems of gasoline engines depending on the environment temperature. For the experiment, conventional fuel filters(paint coated steel case) and specially made testing equipment are prepared. The experimental results shows, an accumulation speed of electrostatic voltage depends on the environmental temperature and new methods of testing procedures are required compare to SAE standards.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.35-41
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• 2001

In recent applications, map controlled thermostat has been adapted to optimize engine cooling system and vehicle cooling system. First of all, this strategy is focused on improving fuel consumption rate and reducing emissions, especially unburned hydrocarbon. The object can be obtained through controlling engine metal temperature by varying engine coolant temperature with engine load and speed. To achieve this goal, it is necessary to understand the characteristics of engine metal temperature and heat rejection rate to coolant. From the results of tested engines, it is obvious that fuel consumption rate has more dominant effect on engine metal temperatures than the corresponding engine power does. Also, Re-Nu relation which shows heat rejection rate to coolant in function of air-fuel mixture and engine specifications has been studied. Also, the empirical Re-Nu relation at full loaded engine was developed.

• Journal of Power Electronics
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• v.6 no.2
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• pp.163-171
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• 2006

In this paper, a Switched Reluctance Motor (SRM) employed in an electric vehicle (EV) is designed using the finite element method (FEM). The static torque of the SRM is estimated through magnetic field analysis. The SRM temperature rise over operation time is estimated through heat transfer analysis. First, static torque and temperature rise over the time of 600W SRM is included in the experiment set, and are compared with the calculated results using the FEM under the same conditions. The validity of the magnetic field analysis and heat transfer analysis is verified by the comparisons. In addition, a 60 [kW] SRM employed in an EV, whose output characteristics are equal to a 1500 [cc] gasoline engine, is designed under magnetic field analysis and heat transfer analysis.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.1
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• pp.75-89
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• 2009

The purpose of this study was to identify $PM_{2.5}$ sources and to estimate their contributions to the border of Yongin-Suwon area, based on the analysis of the $PM_{2.5}$ mass concentration and the associated inorganic elements, ions and carbon components. The contribution of $PM_{2.5}$ sources were estimated by using a positive matrix factorization (PMF) model to identify air emission sources. For this study, $PM_{2.5}$ samples were collected from May, 2007 to April, 2008. The inorganic elements were analyzed by an ICP-AES. The ionic components in $PM_{2.5}$ were analyzed by an Ie. The carbon components were also analyzed by DRI/OGC analyzer. After performing PMF modeling, a total of 12 sources were identified and their contributions were quantitatively estimated. The contributions from each emission source were as follows: 11.3% from oil combustion source, 3.4% from bus/highway source, 5.8% from diesel vehicle source, 4.7% from gasoline vehicle source, 8.8% from biomass burning source, 15.1 % from secondary sulfate, 5.2% from secondary nitrate source, 13.4% from industrial related source, 4.1% from Cl-rich source, 19.6% from soil related source, 1.0% from aged sea salt, and 7.4% from coal combustion source, respectively. This study provides basic information on the major sources affecting air quality, and then it will help to effectively control $PM_{2.5}$ in this study area.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.74-84
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• 2016

After Sep. 2017, the LEV3 emission standard will be applied to gasoline and gas vehicles in Korea. This standard has HWFET and SFTP standard as well as FTP-75. Most of LPG vehicles were certificated as SULEV in Korea. Until now, only FTP-75 standard is applying for the certification but it is expected that HWFET and SFTP are used after beginning LEV3. In this paper, 8 LPG and 4 gasoline vehicles were tested on FTP-75 and SFTP to check whether the LPG vehicles can meet LEV3 SFTP standard or not and to suggest direction of development. Most of test vehicles did not meet the SFTP standard. To make up for the fault, fuel injection control improvement is needed.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.3
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• pp.329-341
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• 2005

The purpose of this study is to study the $PM_{2.5}$ source characteristics affecting the Seoul area using a chemical mass balance (CMB) receptor model. This study was also to evaluate the $PM_{2.5}$ source profiles, which were directly measured and developed. Asian Dust Storm usually occurred in the spring, and very high $PM_{2.5}$ concentrations were observed in the fall among the sampling periods. So the ambient data collected in the spring and fall were evaluated. The CMB model results as well as the $PM_{2.5}$ source profiles were validated using the diagnostic categories, such as: source contribution estimate, t-statistic, R-square, Chi-square, and percent of total mass explained. In the spring months, the magnitude of $PM_{2.5}$ mass contributors was in the following order: Chinese aerosol $(31.7\%)>$ secondary aerosols ($22.3\%$: ammonium sulfate $13.4\%$ and ammonium nitrate $8.9\%)>$ vehicles ($16.1\%$: gasoline vehicle $1.4\%$ and diesel vehicles $14.7\%)>$biomass burning $(15.5\%)>$ geological material $(10.5\%)$. In the fall months, the general trend of the $PM_{2.5}$ mass contributors was the following: biomass burning $(31.1\%)>$ vehicles ($26.9\%$: gasoline vehicle $5.1\%$ and diesel vehicles $21.8\%)>$ secondary aerosols ($23.0\%$: ammonium sulfate $9.1\%$ and ammonium nitrate $13.9\%)>$ Chinese aerosol $(10.7\%)$. The results show that the $PM_{2.5}$ mass in the Seoul area was mainly affected by the Chinese area.