• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.109-115
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• 2011

The shoe brake of the KTX is used in low speed when the electric brake is not effective. The main purpose of the shoe brake is to stop the train to a desired stop point at the station. Lots of defects have been encountered in the shoe brake unit since the KTX started its operation. To improve the reliability of shoe brake unit of the KTX power car, first of all, failure modes of the KTX shoe brake unit were analyzed. Main failure modes are cracks in the shoe friction material and fracture in the welded joints of the shoe backing steel structure. Several methods to remove the defects of the shoe brake unit were proposed and on-board tests were carried out: Increase of the strength of the shoe key and shoe cam, which decreased a little the occurrence of cracks in the shoe friction material; Redesign of the shoe backing steel structure, which eliminated the occurrence of the cracks in the backing plate but could not solve completely the crack problem in the shoe friction material; Development of a new friction material, which with redesign of the shoe backing steel structure could solve satisfactorily the crack problem in the shoe friction material.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.226-233
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• 1999

When we numerically model the bridge under seismic condition, the full model combining the super-structure and the sub-structure is considered for the more accurate results than the separate model. In this case, the super-structure is connected with the sub-structure by the elastic pad shoe that is difficult to model, because it has the three translational elastic stiffness and the three rotational elastic stiffness. The two-node General Link element is derived in finite element equation representing such a pad shoe, and it is verified by comparing the one General Link element model with the corresponding three legacy spring element model. It is easy to model the pad shoe, if the General Link finite element is used. And the seismic analysis result of the bridge full model structure, which is modeled with the General Link element, has been compared with the one of the separate model structure. The present study gives. more conservative result than that of the separate model, which does not consider the dynamic behaviour of the sub-structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.660-663
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• 2001

There is a mechanical device between the superstructure and substructure of a bridge, which transmit vertical load of superstructure to the substructure and absorb horizontal displacement of super structure due to thermal, dynamic, load, etc. In order to meet two requirements at once, the structure of roller between plates is widely used, and this roller between plates is widely used, and this roller shoe system is known to have smaller horizontal movement resistance than any other type of bridge shoe. In this study, rolling friction resistance characteristics of roller-plate friction system is investigated according to roller dimension, vertical load, hardness and roughness of roller and plate. On the base of the results, the rolling friction resistance of large scale roller shoe is evaluated using model experiment.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.103-108
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• 2005

In this study, to develop a flash-less mold for forming of shoe-outsole, experiments and forming analysis were carried out. In order to reduce the extra-materials, offset method and mass distribution method are used in the preform design. The vertical mold structure pressing the preform was introduced to produce a flash-less shoe-sole. To measure the contact status of parting surface of mold, the pressure film has been used. The guide-gutter system and the continuous pressing mold have been developed for the discharge of extra-materials and re-pressing. By the investigation, flash of shoe-outsole was considerably reduced.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.261-268
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• 2012

The purpose of this study was to qualitatively analyze pressure intensity and the center of pressure(COP) trajectory according to shoe type. Subjects were ten first-year female university students. The EMED-AT 25/D(Novel, Germany) was used to measure pressure intensity and COP trajectory. The COP Excursion Index(CPEI) was used for within subject test design. Independent variables were bare feet and six types of shoes. Dependent variables were center of pressure trajectory and pressure intensity. Barefeet and five toed shoes had a similar pressure intensity and COP trajectory. COP trajectory for all other shoe types showed a medial wobble at the heel. Pressure intensity for all other shoe types was related to the structure of the shoes. In conclusion, different shoe types can not only affect gait, but they can also influence foot deformities, pain, and dysfunction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1453-1454
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• 2013

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.89-95
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• 2013

This study focused on the development on functional shoe apparatus so that the appropriate impact can be applied to the feet in order to improve the density of mineral bone at lower limbs. The model with structure proposed in this study had an effective stress about 20 to 100% higher by comparing that of the model without it among most of 15 bone extraction points. Though there is a limitation that the finite element analysis data from the human body model are not the value of mineral bone densities by measuring directly but the effective bone stresses against impact, the proposed structure is designed to influence the increase of bone mass and improve the density of mineral bone by effecting the improvement of the density of mineral bone actually.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.1
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• pp.109-114
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• 2005

In this study, to develop a flash-less mold for forming of shoe-midsole, experiments and forming analysis were carried out. In order to reduce the extra-materials, the final preform has been modified by the experiment of pressure forming at the room temperature. To measure the contact status of parting surface of mold, the pressure film has been used. The midsole mold of the wedge structure type has been developed for the improvement of the contact status. The vertical pressing mold structure was introduced for the production of a flash-less midsole. By the investigation, flash of shoe-midsole was considerably reduced.

• Proceedings of the KAIS Fall Conference
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• 2001.11a
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• pp.196-200
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• 2001

Foot has two functions : one is walking (or propulsion), the other is supporting or protecting of human body. In spite of such important roles, the importance of foot in keeping health has been easily disregarded. The bottom of foot is usually regarded as the second heart, for it is the pocket edition of all the principal parts of human body. Shoe is one of the tools to protect foot, and to wear a good shoe is the most demanded point in keeping health, Shoe can be different in kinds and shapes according to each one's usage. That is, different conditions of different people should have the different results in the material, design, last, pattern and structure in manufacturing shoe. A good shoe is absolutely a shoe with its right suitability, elasticity and adaptability. To make this healthy shoe, it is needed to design in the way of human technology, and the relative and scientific materials are basically required in manufacturing it. Recently there is an increasing demand for milti-functional shoe that can improve the efficiency of work in parallel with the maintenance of health. Accordingly this paper put its main purpose on the development of a healthy shoe based on proper and right theory and test.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.11
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• pp.2228-2236
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• 2002

The axial piston pump by which the mechanical energy is converted into hydraulic energy has been widely used in a press, a injection molding machine and construction equipments due to the high specific power compared to the electric power system. In this paper, the one-piece shoe holder spring of the axial piston pump to simplify its structure and reduce this manufacturing cost was designed and tested. The finite element analyses using the 3-D shell element and contact element were performed to determine the thickness, width and initial angle of the shoe holder spring. Also, the compressive tests of the shoe holder spring were performed and their results were compared with those of the finite element analysis. Also, the performance and endurance limit of axial piston pump with the shoe holder spring were tested and evaluated.