• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.46-56
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• 2006

In this paper, we propose an improved reproduction algorithm for a realistic image of the real scene based on the optical characteristics of the light sources and the materials at the lighting environment. This paper is continuation of the previous study to improve the modeling method of the light sources and the materials and apply this to the real rear lamp of automobile. The backward ray tracing method is first used to trace the light ray from a light source, and also considers the physical characteristics of object surfaces and geometric properties of light radiation to estimate accurately the light energy incoming toward to human eyes. For experiments and verification of the proposed method, the simulation results are compared with the measured light stimuli. Accordingly, the simulation results show that the proposed algorithm can estimate light energy well and reproduce the visually similar image with a scene incident on a sight of viewer.

• Journal of ILASS-Korea
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• v.19 no.3
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• pp.115-122
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• 2014

As a demand for an automobile increases, air pollution and a problem of the energy resources come to the fore in the world. Consequently, governments of every country established ordinances for green-house gas reduction and improvement of air pollution problem. Especially, as international oil price increases, engine using clean energy are being developed competitively with alternative transportation energy sources development policy as the center. Bio ethanol, one of the renewable energy produced from biomass, gained spotlight for transportation energy sources. Studies are in progress to improve fuel supply methods and combustion methods which are key features, one of the engine technologies. DI(Direct Injection), which can reduce fuel consumption rate by injecting fuel directly into the cylinder, is being studied for Green-house gas reduction and fuel economy enhancement at SI(Spark Ignition). GDI(Galoine Direct Injection) has an advantage to meet the regulations for fuel efficiency and $CO_2$ emissions. However it produces increased number of ultrafine particles, that yet received attention in the existing port-injection system, and NOX. As fuel is injected into the cylinder with high-pressure, a proper injection strategy is required by characteristics of a fuel. Especially, when alcohol type fuel is considered. In this study, we tried to get a base data bio-ethanol mixture in GDI, and combustion for optimization. We set fuel mixture rate and fuel injection pressure as parameters and took a picture with a high speed camera after gasoline-ethanol mixture fuel was injected into a constant volume combustion chamber. We figured out spraying characteristic according to parameters. Also, we determine combustion characteristics by measuring emissions and analyzing combustion.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.87-103
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• 1996

The purposes of this research are to investigate the pollution level of heavy metals due to the urbanization and industrialization in the satellite cities of Seoul, and to assess the chemical species and the sources of heavy metals in highly contaminated soils and dusts. Soil and dust samples were collected from the Uijeongbu and the Koyang cities, which are northern and the northwestern satellite cities of Seoul metropolitan city, respectively. Relatively high pH values($6.3{\sim}9.9$) were found in roadside soils compared with agricultural and forest soils. Difference in pH values of soils was not identified between before and after rainy seasons. In spite of no specific pollution sources in the above cities, the contents of Cu, Pb, and Zn in soils and dusts were much higher than the world average contents. The metal levels in dusts were higher than those in soils, but the metal concentration in dusts was significantly decreased after rainy season. Pollution index was high(> 1.0) in the areas of heavy traffic, industrial complex, and city centres. There is an appreciable proportion of total Zn in exchangeable/water-acid soluble fraction. Copper is predominantly associated with reducible and oxidizable phases, whereas Pb is largely in reducible association. It is concluded that the mobility and bioavailability of metals are high in the order of Zn >> Cu > Pb, on the basis of characteristic particle morphology and chemical composition, Pb-containing particles are originated probably from the automobile exhaust, particularly in heavy traffic areas. The metallic forms and iron-oxide associated forms of Cr, Ni, Cu, Zn, and Pb can be assessed as industrial origin.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.5
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• pp.500-508
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• 2014

In the ongoing debates over the need to identify new sources of energy and to reduce the emissions of greenhouse gases. Hydrogen has emerged as one of the most promising alternatives due to its emissions from the vehicle being virtually zero. The governments have identified the development of regulations and standards as one of the key requirements for commercialization of HFCV. Regulations and standards will help overcome technological barriers to commercialization. The development of Global Technical Regulation (GTR) for HFCV occurred under the World Forum for Harmonization of Vehicle Regulations. Development of a technique for safety assessment of HFCV include four tasks, research for regulation system and policy, hydrogen safety, vehicle operation safety and protection against high-voltage. The objective is to establish a technique for safety assessment and amend safety standards for HFCV and consequently reflect research results to vehicle management policy. We devised safety standards and evaluation techniques with regard to high-pressure gas and high voltage of hydrogen fuel cell vehicle. KMVSS for HFCV was amended to June 10, 2014. including the results of the safety assessment technology for high-voltage and hydrogen characteristics.

• Journal of the Korean Professional Engineers Association
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• v.32 no.5
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• pp.118-125
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• 1999

Air pollutant emissions from airplane engines are estimated about 2 to 4 % of mobile source of USA and European countries which is not a large portion of current air pollution. But the passengers and airfreights are continuously increasing 5 to 7% annually and potential demands of air transportation services come to present, it could effect air pollutant emissions of USA will increase within 15 years. In case of our country, there has been continuous increase of air transportation service due to considerable economic growth in recent years and increase of air pollutant emissions of major international airports has followed. Rapid increase of air transportation due to launching of Inchon International Airport could effect air pollution dominantly. By this circumstance environmental specialist as well as mass communication raised necessity of air pollutant emission regulation from airplane engines. It is estimated that air pollutant emissions from airplane engines in our country is 2.7% of automobile sources, 10,809 ton, which is the same level as USA and European countries. It is increased by 12,2% compared to air pollutant emissions during 1996 and it will be increased more than a half of current air pollutant emission within 15 years due to our country's economic condition. Therefore implementation of airplane engine emissions regulation as well as test standards and accumulation of technology about characteristics of airplane engine emission and reduction method are needed. And continuous estimation of air pollutant emission from airplane engines and monitoring of increment as well as development of countermeasures by long term are necessary.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.05a
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• pp.28-32
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• 2000

There are many different chemical pollutants that originate from atmospheric deposition and transportational activities along roads. This paper review the characteristics of heavy metal pollution, relationships between land use and pollutant load in urban area. Four land use areas in Seoul were selected for sampling and study with different characteristics during the period from April 1998 and February 2000. A series of studies have been carried out concerning the physicochemical characteristics of the sediments settling down in a gully pot to evaluate the contamination for heavy metals. The sediment samples from gully pots were characterized by the chemical extraction experiments. Sediments are characterized by very high concentrations of heavy metals, probably because of a long-term accumulation of vehicle- and industrial-related pollutants. The characteristics of heavy metal pollution show that each land use has different sources of contaminations. Mean Zn concentration in Yeouido and Junggu areas is 2-3 times higher than those in Dobonggu area. This suggests that Zn may be derived from the source of automobile traffic. The mean concentrations of Cu and Cr are very significantly high in Junggu and Gurogu areas and indicate that the industrial activities may contribute to the accumulation of Cu and Cr in sediments. The low Pb levels throughout the whole study areas in Seoul can be accounted for the use of unleaded gasoline since 1987.

• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.1019-1025
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• 2004

Pressure variation is one of the major sources on noise emission in the axial type oil piston pumps. Therefore, it is necessary that the pressure variation characteristics of the oil hydraulic piston pumps be clarified to reduce the pump noise. Pressure variations in a cylinder at the discharge region and the pump noise were simultaneously measured with discharge pressures and rotational speeds during the pump working. To investigate the effects of the pre-compression and the V-notch in the valve plate, we used the three types of valve plates. In this research, it is clear that the pressure variation characteristics of axial type oil piston pumps is deeply related to the pre-compression and to the V-notch design in valve plate. Therefore, we could reduce the pump noise by using the appropriate pre-compression angle and the notch design that are between the suction port and the discharge port in valve plate.

• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.915-923
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• 2004

This study investigated the fatigue lives and mechanical properties of the carbon black filled natural rubber for the vibration-proof parts of the railway vehicle and automobile. The carbon blacks were one of the sources of crack nucleation and crack propagation in the rubber matrix, like the cementite and the maganese sulfide in iron matrix. Different kinds of carbon blacks resulted in different fatigue lives, critical J-values, and fracture morphologies. It was noticed that the critical J-value remained almost the same regardless of the length of a pre-crack. In addition, different kinds of carbon blacks generated different fracture morphologies, and microscopic and macroscopic roughnesses. The critical J-value has linear relations to the roughness, and it seemed related to the size distribution of carbon black particles. By reviewing all the experi-mental data, we found the factors that were related to the fatigue lives, and the logarithmic value of the fatigue life could be linearly expressed by the combination of the critical J-value and the macroscopic roughness. We also proposed a new estimative equation of fatigue life.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.1
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• pp.64-70
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• 2015

Organic Rankine cycle (ORC) is an useful cycle for power generation system with low temperature heat sources ($80{\sim}400^{\circ}C$). Since the boiling point of operating fluid is low, the system is used to recover the low temperature heat source of waste heat energy. In this study, a ORC with R134a is applied to recover the waste energy of condenser of coal fired power plant. A system model is developed via Thermolib$^{(R)}$ under Simulink/MATLAB environment. The model is composed of a refrigerant heat exchanger for heat recovery from coal fired condenser, a drum, turbine, heat exchanger for ORC heat rejection, storage tank, water recirculation pump and water drip pump. System analysis parameters were heat recovery capacity, type of refrigerants, and types of turbines. The simulation model is used to analyze the heat recovery capacity of ORC power system. As a result, increasing the overall heat transfer coefficient to become the largest of turbine power is the most economical.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.704-711
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• 2017

Korea, which has a high dependency on energy imports, is greatly affected by fluctuations in international oil prices. In order to offset these effects, various policies such as 'diversification of energy sources' and 'energy mix' are being pursued. Renewable Fuel Standard (RFS) is a policy promoted for this purpose, and a compulsory mixing system is applied only to the diesel. In order to reduce dependence on fossil fuels in various countries, they are concentrating on the dissemination of bio-alcohol as well as bio-diesel, and commercialization through various verification. In this study, evaluation of domestic materials and vehicles was carried out to promote domestic bio alcohol fuel. We analyzed the fuel characteristics of domestic quality standard items by mixing them with gasoline of automobile at a certain mixing ratio (0%, 3%, 6%, and 10%).