• 한국경영과학회지
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• 제10권1호
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• pp.65-78
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• 1985

In this paper, the approach getting a total demand by forecasting the new demand and the replacement demand separately and adding them is used for long term forecasting of durable goods. Cross country analysis using the income as an independent variable and S-shaped growth curve as a fitting model is developed as a method of forecasting new demand. To get the replacement demand the methods using the number of ownership and the replacement rate and the methods using the past demand and the distribution of the product life are proposed. And the theoretical explannation for product life cycle's diversity, which is the one of the major considerations in the long term forecasting, is attempted by the combination of the new demand and the replacement demand patterns. This is applicated the long term forecasting of Korean passenger cars.

• 한국대기환경학회지
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• 제3권2호
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• pp.39-45
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• 1987

Rubber particles emitted from automobile tire tread by abrasion were collected by Andersen sampler with atmospheric dusts. The samples of atmospheric dusts at each stage were analysed for rubber particles by Curie point pyrolysis-gas chromatography with Apiezon grease L column. Pyrolysis was done at 740$^circ$C for 5 seconds. In the pyrogram, NR rubber (bus and truck tire tread) was determined by isoprene peak, and SBR rubber (passenger car tire tread) was determined by styrene peak simultaneously. The size distribution of rubber particles was proportioned with the size of rubber particles. The concentrations of NR and SBR rubber were 0.23 $\mug/m^3$ and 1.31 $\mug/m^3$, respectively, in the atmospheric dusts which were collected from the street in front of Yonsei University on April 1986. The ratio of tire tread rubber in the atmospheric dusts was about 0.63%.

• Tribology and Lubricants
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• 제14권1호
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• pp.37-44
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• 1998

The adequate design of a passenger car's braking system, which is directly related to the safety of a car, is very important since the safety is an essential design parameter of a car to keep men and car from the damage. The general method to verify the performance and safety of a braking system is still based on the trial-error experiments. However, the design based on experiments costs high and is time-consuming method. So it is desirable to use the numerical analysis method for the reduction of cost and time in the design of a braking system. In this paper, the thermal characteristic of a ventilated disc brake has been analyzed as a function of the car speed and a deceleration during quick braking.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.626-631
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• 2007

With its critical pending task of putting the management into the right track, it is extremely important for the Korea Railroad Corporation to incorporate more reasonable distribution into train consists to cut down its operation costs and attain higher income surplus in the Metropolitan Train Business. Furthermore, for Jung-ang Line soon to be operated without any crew on-board, more adequate train formation looks very indispensable mainly to satisfy transportation demands as well as enhance the passenger safety. This paper will examine the Jung-ang Line with hourly-basis congestions and inter station O/Ds to get the better operation schedules and trainset numbers.

• 대한교통학회지
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• 제5권1호
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• pp.85-99
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• 1987

The transport a administration in Korea is meeting demands of developing international multimodal transport system. In the past, as Korea transport policy has been emphasizing on the passenger traffic, the physical distribution sector is far behind international trend. Regarding the urging necessities of reducting costs in transport in order to upgrade the competitive edge of industries, Korea has to develop the most efficient transport system so called international multimodal transport system. The existing transport system is inefficient because each transport mode is separate, so this system is aiming at reducing cost and time and developing freight transport. The scope and scheme of this thesis should be as following. Chapter 2. Systems Approach of International multimodal transport 1. general systems theory 2. definition of International multimodal transport system 3. MTO (multimodal transport operator) Chapter 3. Current Situation and Problems of this System. 1. international law and practice 2.current situation A. Europe B. U.S. C. Japan D. Korea Chapter 4. Policy Goal for Improving this System Chapter 5. conclusion.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.298-303
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• 2000

A procedure to predict the fatigue life of rubber components based on the signed principal strain method was proposed. A tension-compression rubber specimen with Jang-gu shape was designed and principal strain distribution was obtained by using the nonlinear finite element analysis. Finite element analysis and fatigue test of strut rubber mount were conducted to evaluate the fatigue life prediction procedure proposed. A procedure was employed to predict the fatigue life of strut rubber mount. Predicted fatigue lives have a good agreement with tested lives within a factor of 3.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.40.1-40.1
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• 2010

Recently high strength steel sheets with high formability for automotive parts have been being developed to meet the demands for passenger safety and weight reduction of car body. Among these high strength steels, dual-phase steels are regarded as one of the attractive steels due to their excellent mechanical properties including high strength and ductility. However, to be successfully applied to automotive parts they should be corrosion resistant enough to satisfy the required quality of car maker. This also requires their feasibility for galvannealed production including hot dip galvanizability. In this study has been placed on understanding the effects of heat-treatment(austenizing and isothermal treatment) on the microstructures and mechanical properties of a 0.06C-0.03Si-2.0Mn high strength steel for cold forming. The microstructure and phase distribution were examined with eth aids of SEM, EBSD, TEM etc.. Through the study the production of 590MPa grade DP GA steels with good formability and galvaniability were shown to be possible.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.994-995
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• 2014

Supporting stiffness of seats is an important component affecting dynamic characteristics cognized by a passenger. To analyze dynamic characteristic of a seat for vehicles operating on various road conditions, the seat vibration from road irregularity should be understood and compared. In this study, the seat is analyzed as distributed supporting system. The dynamic stiffness is measured using masses. The characteristic of the seats is analyzed by measuring distributed dynamic stiffness. The distributed dynamic stiffness of the seat is estimated on various locations and the effects of each component such as spatial distribution, compression level and vibration amplitude are analyzed. The influence of seat cover, elastic support and flexible polyurethane foam on the measured stiffness was analyzed.

• 한국가시화정보학회지
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• 제5권2호
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• pp.20-25
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• 2007

The geometry of a commercial passenger airplane is realized based on a Boeing 747-400 model through the photographic scanning and reverse engineering. The each element consisting of the plane such as fuselage, wing, vertical fin, stabilizer and engines, is individually generated and then the whole body is assembled by the photomodeler. The maximum error in the realized airplane is about 1.4% comparing with the real one. The three-dimensional inviscid steady compressible governing equations are solved in the unstructured tetrahedron grid system, and in a finite volume method using STAR-CD when the airplane flies at the cruise condition. The pressure distribution on the surface and the wing-tip vortices are visualized, and in addition to the aerodynamics coefficients, lift and drag are estimated.

• 오토저널
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• 제6권4호
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• pp.54-61
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• 1984

Numerical calculation of the flow field past a passenger car was carried out by using a panel method with a small computer of 5Mbyte memory size. The shape of car body was simplified and reconstructed by 2180 panels on which a constant strength sink (or source) was distributed. The separation of flow from the surface and the wake flow were not considered in the calculation because of the computer memory limitation. All of the results of calculation were presented by using a 3-dimensional computer graphics. In spite of small memory size of computer, generally good agreements were obtained, except the separated region, from the comparison of pressure distribution between numerical analysis and wind tunnel experiment with 1/5 scaled model.