• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.501-510
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• 2003

The spot welded sections of automobiles such as the hat and double hat section members, absorb the most of the energy during the front-end collision. The purpose of this study was to analyze the collapse characteristics of spot welded section members with respect ttl the pitch or spot welds on flanges. through impact experiments and computation for para-closed sections and perfectly closed sections. The hat shaped section members were tested at the impact collapse velocities of 4.72 m/sec, 6.54 m/sec and 7.19 m/sec and double hat shaped section members were tested at the impact collapse velocities of 6.54 m/sec, 7.19 m/sec and 7.27 m/sec. A commercial LS-DYNA3D was used to simulate the collapse behavior of the hat and double hat shaped section members. The validity of the simulation was to be proved by comparing the simulation results and the experimental results.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.109-116
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• 1998

As of July 1997, the registered number of automobiles exceeded 10 million and Korean auto industry produced 2,850,000 cars. Many environmentalists warn that the passenger cars are not sustainable urban transportation system in large cities. The cars produce about 80% of air pollutants, and consume 30% of petroleum imported. For the past 30 years the administration increased the road system, but the length of road per car is decreased from 813m in 1965 to 9m in 1995. The cost of traffic congestion was estimated to be \14.7 trillion in 1996, and is feared to increase without changing the present transportation system. The undesirable impact of cars include the casualties from traffic accidents, insurance loss, and separation of human relatioships. To construct sustainable urban transportation system, three principles should be followed. The first principle is to make the urban streets walkable for the people. The second principle is to encourage bicycling. Roads and traffic systems should be designed to let bicylces travel safely. The third principle is to supply more buses and construct integrated transportation system based on buses. The subway system is too expensive to construct and without the support of a well-organized bus system it may not work efficiently. The Brazilian city of Curitiba has constructed a very efficient bus system only with 1/80 of the estimated cost of subway system. The car-oriented transportation system does not seem to be an envrironmentally sustainable transportation system in most of the Korean cities.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.4
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• pp.301-308
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• 2006

Today's automobiles are changing into miniaturization and light weight for saving natural resources and energies. In order to raise the sufficiency of fuel consumption, new mechanism and components are required. Therefore, the expectations on the new materials are very high. Especially, Al materials are widely used to reduce the motors weight. Al using in automobiles is mostly casting material, and the material is developing rapidly in step with technical innovation. Al die casting has become an important field, as we are turning today's motor into light weight. One of the parts in steering system, valve housing, plays a role to reduce the operating effort of drivers. If valve housing being a part of steering system is produced by gravity casting, the space that manufacturing equipments are installed will be increased, and more energies and workers will be needed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.04a
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• pp.113-118
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• 1997

This paper presents the dimensional synthesis and kinematic analysis of the RSCS-SSP motion generating spatial mechanism using the displacement matrix method. This type of spatial mechanisms is used for the Mcpherson suspension in small automobiles. It is modeled for the wheel bump/rebound and steering motion. First, the suspension is modeled as a multiloop spatial rigid body guidance mechanism for the two major motions. Then the design equations for SSP, RS, and SC strut links are applied to synthesize an RSCS-SSP for up to three prescribed positions for the steering motiom from the suspension design specification. Thus a RSCS-SSP mechanism which is synthesized is also analyzed for the displacement during the steering motion.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.8
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• pp.1378-1391
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• 2010

This study examines the wearing conditions of working clothes according to the working environment and working processes at machinery, automobile, shipbuilding industry sites. It also investigates the relationship between the wearing sense of working clothes and the overall comfort according to work processes. The hazardous working environment was high in the order of the shipbuilding industry, machinery, and automobiles. The findings on the harmful overall work environmental factors were the noise, heavy dust, and noxious fumes, respectively. In general, the satisfaction with the wearing performance of working clothes was low especially with regard to sweat absorbency, sweat permeability, body protection and covering, and the work motion suitability. In respect of the correlation between the overall comfort and the wearing sense of working clothes, the satisfaction was decreased in the order of movement comfort, sensual comfort, and physiological comfort.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.99-106
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• 2006

In this paper, implementation of active mufflers using multiple channel adaptive IIR filter is presented. Usually, recursive LMS(RLMS) algorithms for adaptive IIR filters are highly efficient than filtered-X LMS(FXLMS) algorithms, when the order of both algorithms are the same. However, RLMS algorithms usually diverge before the algorithms arenot yet converged. So, the prefilters are presented to improve the stability by pulling the poles of feedback control transfer function in the beginning of active noise control and returning the original poles after the filters converge. The engine noises of diesel engine automobiles and gasoline engine automobiles are analyzed and the mathematical model of an active muffler is derived. Computer simulations and experiments are performed to show the effectiveness of the proposed systems.

• Journal of the Korean Institute of Rural Architecture
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• v.20 no.3
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• pp.1-9
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• 2018

This research aimed to identify walking trails' purpose of its use and the factors that influence the selection. For this, a survey targeting the walking trail users was conducted in 2016 to question the research aim stated above. The mean number of walking trail usage in a month was 2.51 times and the duration of use ranged from one to ten hours, with the average of 2.5 hours. The main reason for the usage was to maintain physical health and the following was for mental relaxation, thus showing more than 90% of the people concerned with physical and mental health. Walking trails near the residences had the greatest percentage and trails that include mountains, rivers, seas and lakes were the following. Trails near historical locations or countryside showed a lower percentage. The choices showed relevance to the proximity as a standard of selection. The next highest percentage was the convenience of transportation. Additionally, people that access the trails three or more times were inclined to be influenced by the installation of exercising equipment. The aspect of facilities showed that the place for relaxation was a significant selection factor such as bathrooms for 20s to 30s and exercising equipments for people older than 50. To access the walking trails, people reach it by automobiles, public transport, walking and bicycles and out of these, automobiles had the highest percentage.

• Corrosion Science and Technology
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• v.16 no.3
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• pp.128-140
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• 2017

Aluminum alloy matrix may be used for manufacturing lighter automobiles. However, galvanic corrosion may occur between the rivet joint combining aluminum alloy matrix and a CFRP (carbon fiber reinforced plastic) laminate. The possibility of galvanic corrosion may be investigated by measuring galvanic couple currents. Two types of galvanic current measuring methods were used. One method is to use potentiodynamic polarization curves and the other is the ZRA (zero resistance ammeter) method. For galvanic corrosion experiments graphite, a major component of CFRP, was used with carbon steel (rivets) and 6061 aluminum alloys. Regardless of carbon steel, Ni deposited carbon steel, and 316L stainless steels we also investigated the possibility of reduction in galvanic corrosion. Results revealed that even though Ni deposited carbon steel or 316L stainless rivet may slightly increase galvanic current density between those and Al matrix, substitute rivets for carbon steel may be considerably useful for reducing overall galvanic corrosion.

• Carbon letters
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• v.15 no.3
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• pp.203-209
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• 2014

The adsorption of volatile organic compounds (VOCs) was carried out using an activated carbon fiber (ACF) filter in an automobile. The adsorption capacities of formaldehyde, toluene, and benzene on an ACF filter were far better than those of a polypropylene (PP) mat filter and combined (PP+activated carbon) mat filter by batch adsorption in a gas bag. In a continuous flow of air containing toluene vapor through an ACF packed bed, the breakpoint time was very long, the length of the unused bed was short, and sharp "S" -type breakthrough curve was plotted soon after breakpoint, showing a narrow mass transfer zone of toluene on the ACF. The adsorption amount of toluene on the ACF filter was proportional to the specific surface area of the ACF; however, the development of mesopores 2-5 nm in size on the ACF was very effective with regard to the adsorption of toluene. The ACF air clarifier filter is strongly recommended to remove VOCs in newly produced automobiles.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.83-86
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• 2005

The front-end side members of automobiles, such as the hat-shaped section member, absorb most of the energy during the front-end collision. The side members absorb more energy in collision if they have higher strength and stiffness, and stable folding capacity (local buckling). Using the above characteristics on energy absorption, vehicle should be designed light-weight to improve fuel combustion ratio and reduce exhaust gas. Because of their specific strength and stiffness, CFRP are currently being considered for many structural (aerospace vehicle, automobiles, trains and ships) applications due to their potential for reducing structural weight. Although CFRP members exhibit collapse modes that are significantly different from the collapse modes of metallic materials, numerous studies have shown that CFRP members can be efficient energy absorbing materials. In this study, the CFRP side members were manufactured using a uni-directional prepreg sheet of carbon/Epoxy and axial static collapse tests were performed for the members. The collapse mode and the energy absorption capability of the members were analyzed under the static load.