• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.162-167
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• 2002

An automotive wheel bearing is one of the most important components to guarantee the service life of a passenger car. The endurance life of a bearing is affected by many parameters such as material properties, heat treatment, lubrication conditions, temperature, loading conditions, bearing geometry, internal clearance and so on. In this paper, we analyze the relation between loads and deformations of wheel bearing units. On the basis of it, we calculate the endurance life of wheel bearing units and suggest a method to determine the initial contact angle to achieve a maximum endurance life with considering stress concentration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.670-673
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• 2002

Automotive wheel bearings are one of the most important components to guarantee the service life of a passenger car. The endurance life of a bearing is affected by many parameters such as material properties, heat treatment, lubrication conditions, temperature, loading conditions, bearing geometry, internal clearance and so on. In this paper, we analyze the relation between loads and deformations of wheel bearing units. On the basis of it we calculate the endurance life of wheel bearing units and analyze the contribution of bearing geometric parameters on the endurance life by using Taguchi method.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.38-44
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• 2003

In this study, endurance limit and fatigue behavior of load carrying fillet welded cruciform joints depending on commonly used welding methods such as SMAW, SAW, MIG and FCAW are investigated. In respect of endurance limit SMAW specimen showes highest result, and then MIG, SAW, FCAW in descending order. However, SMAW specimen showes lowest crack growth rate and it followed by MIG, FCAW, SAW. By these results, it is needed to use SMAW or MIG welding methods for welding structures with small welding capacity and SAW or FCAW methods for large welding structures with respect to economic benefits and operation efficiency of welding. It was also shown fatigue crack growth rate was more influenced by the strenght of welding materials than the endurance limit of welding materials.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1146-1151
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• 2014

The equipment in ships and railway vehicles are continuously exposed to vibration, and its durability is very important. Therefore, consumers require the verification of the performance of equipment via standardized tests under the given environments to improve and stabilize the performance. In this study, a durability improvement and stabilization plan was proposed, which included the exploratory vibration test, variable frequency test and endurance test for the electrical equipment according to the vibration environment. It is expected that this study results will improve the technological competitive power of the ship and railway-related manufacturers and contribute to the equipment development and export.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.11-15
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• 2011

This paper propose the test method for a performance of the myoelectric hand prosthesis(MHP) controlled according to the myoelectric signal generated in the human muscle. The MHP consists of a mechanical hand, a surface myoelectric sensor(SMES) for a measuring myoelectric signal, a control system and a charging battery. The two commercialized MHP is tested for the grip endurance property. The test results is not difference a noise and a grip force. The proposed test method is proved the reliability of MHP by the endurance test.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.226-227
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• 2005

In this study, it was investigated about endurance and fatigue crack propagation rate of according to welding methods of SMAW and FCAW commonly using for welding structures in present. Endurance limits carried out highly in the order of SMAW, FCAW and fatigue crack propagation rate out lowly in the order of SMAW, FCAW. By these results, it is needed to used SMAW welding methods for welding structures with small welding capacity and FCAW methods for large welding structures after consideration about economic gains and operation efficiency of welding. Fatigue crack propagation rate is more effected by strength of welding materials than endurance limit of welding materials according to welding methods..

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.164-168
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• 2003

An automotive wheel bearing is one of the most important components to guarantee the service life of a passenger car. The endurance life of a bearing is affected by many parameters such as material properties, heat treatment, lubrication conditions, operating temperature, loading conditions, bearing geometry, the internal clearance of bearing and so on. In this paper, we analyze the relation between loads and deformations of wheel bearing units for optimal bearing unit design. On the basis of it, we calculate the endurance life of w heel bearing units and analyze the contribution of bearing geometric parameters on the endurance life by using Taguchi method.

• Korean Journal of Health Education and Promotion
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• v.21 no.4
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• pp.99-108
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• 2004

The purpose of this study was to examine the relationship between physical fitness, and physical and psychological stress of females. The subjects of this study were 139 adult women, without a specific medical illness. The stress level was evaluated by Derogetis's checklist-90-Revision symptom of physical and psychological stress (Cronbach's a=0.88, 0.87). The physical fitness factors in this study were cardiopulmonary endurance, muscle endurance, muscle strength, power, agility, and flexibility. To analyze the data to examine the relationship between the physical and psychological stress, and physical fitness, correlation analysis was applied. The findings of this study were as follows. First, among the physical fitness factors, cardiopulmonary endurance, along with muscle strength and power had significant relations with physical stress (p<.01). Second, among the physical fitness factors, cardiopulmonary endurance showed a significant relation with psychological stress (p<.05).

• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.1-6
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• 2007

In order to evaluate fatigue endurance for the rocker arm of a diesel engine, stress measurements were performed using the strain gages attached near the neck, where is one of the most critical region in the rocker arm, in variation of the engine speed. The fatigue life experiments were carried out on miniature specimens from the rocker arms. For evaluating the fatigue endurance of the rocker arm, the S-N data were compared with the stress analysis results through FEM analysis of the rocker arm. The effective stress of the neck region was determined 17.7MPa through FEM analysis of the rocker arm. Conclusively, on the basis of fatigue limit, the rocker arm has a safety factor of 2.8 or 3.4 from the stress measurement or FEM results, respectively.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.867-872
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• 2007

The aging is related to numerous changes in our body system which declines functional ability. The functional ability in advanced age can be evaluated by the 4 components of fitness (cardiorespiratory endurance, muscular strength and endurance, flexibility and body composition). The understanding and knowledge of changing 4 components of fitness and the role of exercise on the process of aging is of paramount importance. Despite exercise and physical activity have been shown to delay the process of aging, the exercise guidelines and recommendations for old adults are not well published. This review is to presents the age-related changes in each component of fitness and to present current guidelines and recommendations for exercise in older adults.