• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.298-304
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• 2012

The development of low rolling resistance tire with weight reduction in tire and vehicle may induce high level of tire/road noise, especially the rumble road noise on rough road. In this paper, the design factor for good rumble noise is considered in view of tire and vehicle. For the 3 mid-sized sedans, the rumble noise is very sensitive to the test vehicle. And it is concluded that the tire with high tread part stiffness and low sidewall part stiffness shows best rumble noise performance, and the rumble noise is in trade-off relation with cavity resonance noise. So, it is desirable to select and change proper construction design factors to have good tire/vehicle rumble noise.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.18-20
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• 1995

In this paper we presented a calculation method of leakage inductance in electrical machines. For its accurate calculation the finite element method is applied to the analysis of magnetic field distribution. The self and mutual inductances are derived using the results of the magnetic field analysis and the leakage inductance is easily obtained from these inductances. As numerical examples, we tread a single phase transformer and a rotor slot model of induction motor. In the finite element analysis we used the 2D linear magnetostatic formulation with the first-order triangular element.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.87-92
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• 2000

In this paper, we investigated the braking performance of a composite brake shoe for power car. Laboratory bench test and field tests were carried out to characterize the braking performance by the parameters such as friction coefficient, wear rate, braking temperature and stopping distance. Density distribution was found to have a significant influence on the wear rate. The composite brake shoe with even density distribution showed better braking performance. The braking performance of a composite brake shoe was also compared with that of a cast iron brake shoe which is currently being used. The result indicated the performance of the composite brake shoe is better than the cast iron brake shoe.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.127-134
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• 2002

This study present a direct steering system using rack and pinion for ultra-small vehicles. The traditional small vehicles for special use had the limitation of space by reason of short wheel tread. These vehicles has adopted a indirect steering system or a center arm system for steering. The disadvantages of these system were deterioration of gear efficiency and increase of parts. For direct-linkage to both knuckles, steering system is made up of out-side tie rods, tie-rod ends, and gear box. Thus, the proposed system has a minimum number of parts. The experimental results show a maximum efficiency at minimum steering angle and a minimum clearance circle. These effects were accomplished by adopting a Ackerman-Jantaud theory.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.982-987
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• 2006

In general, the braking system of high speed train has an important role for the safety of the train. To stop safely the train at its pre-decided position, it is necessary to combine property the various brakes. Generally high speed train has adopted a combined electrical and mechanical (friction) braking system. Electrical brakes are consist of rheostatic brake, regenerative brake and eddy current brake and mechanical brakes are composed of disc brake, wheel disc brake and tread brake. In this paper, we introduce braking performance analysis and inspection though simulation and research to reduce braking distance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.340-343
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• 2006

As the needs of consumer on ride comforts increase and the reduction of road traffic noise tightened step by step, the power unit noise emitted by cars has been reduced. It has been found that tire noise dominates noise produced by the power-train when vehicles are driven at high speeds. Therefore, in these days, tire/pavement noise is concerned. Tire/pavement noise is affected by pavement type and vehicle???s transmission loss. Tire noise mechanism is produced by several mechanisms. The sound of tire can propagate either through the air or through the structure of vehicle. Pattern noise is the result of pressure variations through the air to the interior side of vehicle. Especially, on smooth asphalt the periodicity of tread design, pitch sequence is important factor, which have an influence on the reduction of tire noise.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.129-134
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• 2004

Author presented some study with a title of "automatic control for ship collision avoidance system" in previous papers. The paper reported the tread of the study, un-sloved issues and outcome of the study. In this paper, some additional results will be reported. The first is the algorithm of avoidance of group ship that is one of the un-sloved issues. The algorithm is useful when a ship takes an avoiding action toward group fish boats and approaching group merchant vessel. The second is unified model for calculating ship collision risk. The collision risk changes with various meet type of ships. Therefor newly-developed model is suggested to take into account of these situations. Finally simulation is carried out to verify suggested algorithm and model in various ship encounter situations..

• Journal of Sensor Science and Technology
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• v.13 no.3
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• pp.244-251
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• 2004

In general, the braking system of high speed train has an important role for the safety of the train. To stop safely the train at its pre-decided position, it is necessary to combine properly the various brakes. Korean high speed train (HSR 350x) has adopted a combined electric and mechanic (friction) braking system. Electric brakes are consist of rheostatic brake, regenerative brake and eddy current brake and mechanical brakes are composed of disc brake, wheel disc brake and tread brake. In this paper, the measuring method that can take a measurement of the braking forces for disc brake and wheel disc brake has been suggested and we have verified that this method is valid through on-line test of HSR 350x.

• Structural Engineering and Mechanics
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• v.22 no.5
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• pp.517-539
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• 2006

Friction problems involving rubber components are frequently encountered in industrial applications. Their treatment within the framework of numerical simulations by means of the Finite Element Method (FEM) is the main issue of this paper. Special emphasis is placed on the choice of a suitable material model and the formulation of a contact model specially designed for the particular characteristics of rubber friction. A coupled thermomechanical approach allows for consideration of the influence of temperature on the frictional behavior. The developed tools are implemented in the commercial FE code ABAQUS. They are validated taking the sliding motion of a rubber tread block as example. Such simulations are frequently encountered in tire design and development. The simulations are carried out with different formulations for the material and the frictional behavior. Comparison of the obtained results with experimental observations enables to judge the suitability of the applied formulations on a structural scale.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.193-194
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• 2012

Most of the Historic Preservation Areas are very weak to fire disasters. The aim of this study is to build a proposal-scheme for evacuation routes planning at a large-scale disaster in a historic preservation area. The study area is a preservation area called "Hizen-Hama-Shuku" which has many straw-roofed wooden houses in Kashima city, Japan. To achieve this aim, outline of the scheme is discussed. The proposal-scheme of evacuation routes consists of objectives to propose, target time to evacuate for the refuge place, evaluation method, and procedures. The existing condition and the measures are evaluated using the software "SimTread".