• Journal of Auto-vehicle Safety Association
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• v.14 no.3
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• pp.30-34
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• 2022

The CFT(Cornering Fatigue test) and RFT(Radial Fatigue Test) are tests for evaluating the endurance of the disc and rim region of the wheel. In recent, automobile wheel safety standards have been revised and the applied load and target life criteria are different from existing conditions. The verification evaluation of all wheels requires a lot of time and cost. In this study, the endurance severity of each test was compared through strain-life approach by selecting 4 steel and 8 aluminum wheels.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1127-1132
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• 2003

Suspension system of vehicle have enough endurance during its life time to protect passenger. Spring is one of major part of vehicle. Thus, a fatigue strength evaluation for leaf spring based on road load response was carried out. At first, strain of leaf spring is measured on the city condition and proving ground condition. And next, the damage analysis of road load response data was carried out. And fatigue test of leaf spring were also carried out. Based on -N life relation, fatigue life of leaf spring was evaluated at belgian mode, city mode and drawing test specification. After that, it is compared the design life of leaf spring and evaluated fatigue life by belgian mode, city mode and drawing test specification. From the above, the maximum load-fatigue life relation of leaf spring was defined by test. and new test target of belgian mode and city mode was proposed to accept design specification of leaf spring. It is expect that proposed test target can verify leaf spring fatigue endurance at specific road condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1429-1433
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• 2004

Recently, a dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOK corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque form input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element methode and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test methode when applied rated torque.

• Journal of Power System Engineering
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• v.18 no.2
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• pp.31-36
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• 2014

In this paper, pneumatic valve which consists of valve body, valve controller, nozzle and a multi-bender PZT actuator was suggested and fabricated. The fabricated pneumatic valve was experimented for performance evaluation. From the experimental results, we know that the flow rate of the suggested valve is 23 lpm at the pressure difference of 1bar and the maximum flow rate is 30 lpm at the pressure difference of 4 bar. The flow rates after endurance test of 9.8 million were 22.57 lpm and 28.62 lpm at the pressure difference of 1bar and 4bar, respectably. Finally, it was verified that the B10 life of the suggested pneumatic valve is over 50 million.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1998.11a
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• pp.73-76
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• 1998

To use glazing systems protected by automatic sprinklers as fire barriers in building compartmentation, fire endurance tests of these systems have been performed by several research workers. Most of the tests concerned the types of glasses and sprinklers, sprinkler water flow rate, and sprinkler activation time. Horizontal side wall sprinklers and window glazing systems with a vertical center mullion were mainly applied in the tests. In the study, full-scale fire endurance tests were carried out to verify the ability of large glazing systems divided by a horizontal mullion and protected by pendent vertical sprinklers. The result shows that the protrusive length of the horizontal mullion, which is perpendicular to the glass surface, is the main parameter that determines the fire resistance rating of the systems. The mullion obstructs the water flow in the glass.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.47-54
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• 2005

A dangerous event occurred at the field industry and mechanical system. At developed by SUNGGOKNANOTECH corp. a R-L clutches of a small and high capacity serves safety device from a variety environment of mechanical system, it permits transmission of driving torque from input to output shaft in both directions of rotation, but restrains any feedback torque of the driven load from rotating the output shaft in either direction. This study was carried out to demonstrate through finite element method and durability estimation for safety of the R-L clutches without sliding during the engagement process. As results, we organized about endurance test method when applied rated torque.

• The Journal of Korean Physical Therapy
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• v.23 no.3
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• pp.57-63
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• 2011

Purpose: The purposes of this study were to investigate the effectiveness of Pilates exercise on Fitness Factors related to motor performance including flexibility, agility, power, balance, and muscle endurance. Methods: Forty subjects were randomly allocated to one of two groups. The Pilates group did Pilates exercises 3 times a week for 8weeks, 60 minutes each time, and submitted to evaluation of protocols to assess sitting and reaching tests, a standing broad jump test, a side step test, a balance test using a Biodex Stability System, and muscle endurance using CSMI. Results: The Pilates group (n=20) participated in Pilates exercises three times in a week for eight weeks. The results show significant post-test differences in the Pilates group in the following areas: flexibility, agility, power, balance and muscle endurance. There was no significant increase in the control group. Post-exercise, there was no significant difference between the Pilates and control group. Conclusion: The Pilates method can offer significant improvement in personal flexibility, agility, power, balance, and muscle endurance. This study suggests that individuals can improve their Fitness Factors related to motor performance using Pilates exercises that do not require equipment or a high degree of skill. Further study is required to quantify the benefits of Pilates exercise.

• PNF and Movement
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• v.18 no.2
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• pp.205-214
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• 2020

Purpose: The purpose of the study was to assess the effects of proprioceptive neuromuscular facilitation (PNF) training and respiratory muscle endurance training on pulmonary function and activity in chronic stroke patients. Methods: The participants were 25 chronic stroke patients. They were assigned to two groups: a PNF and respiratory muscle training group (experimental group; n = 12) and a conservative training group (control group; n = 13). The experimental group completed 50 minutes (30 minutes of conventional physical therapy, 10 minutes of PNF training, and 10 minutes of respiratory muscle endurance training). The control group also completed 50 minutes (30 minutes of conventional physical therapy and 20 minutes on a full-body workout machine). Pulmonary function and activity were measured before and after the intervention, using Cosmed to analyze pulmonary function and 6MWT as clinical evaluation indicators. Results: Both groups showed significant within-group differences on all tests before and after the intervention; the experimental group showed greater improvement on all tests. Conclusion: The findings confirm that PNF training and respiratory muscle endurance training have a positive effect on pulmonary function and activity index in chronic stroke patients.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.38-42
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• 2003

The use of VPI impregnated mica tape as high voltage insulation for large rotating electric machines requires a careful balance of processes and materials to obtain the desired electrical, mechanical and thermal characteristics. The stator insulation systems such as epoxy bonded high voltage mica tape have been produced for many years. One such system employing an epoxy and anhydride impregnating resin developed by Hyundai Heavy Industries, Co. (hereafter, HHI), to satisfy customer requests for an epoxy bonded insulation system. HHI applies the following electrical and thermal evaluations such as dielectric breakdown, voltage endurance, dissipation factor vs. temperature, isothermal weight loss, and so on. A detailed laboratory evaluation can describe specific physical limitations for an insulation system and permit development of long-term operation guidelines that permit full utilization of the proposed system. HHI has found these evaluations very helpful in qualifying insulation system for the repair of both large motors and generators.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.11
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• pp.1979-1985
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• 2003

Fretting is a kind of surface degradation mechanism observed in mechanical components and structures. The fretting damage decreases in 50-70% of the plain fatigue strength. This may be observed in the fossil power plant and the nuclear power plant used in special environments and various loading conditions. The thermal degradation of material is observed when the heat resisting steel is exposed for long period time at the high temperature. In the present study, the degraded 1Cr-0.5Mo steel used for long period time at high temperature (about 515$^{\circ}C$) and artificially reheat-treated materials are prepared. These materials are used for evaluating an effect of thermal aging on the fretting fatigue behavior. Through the experiment, it is found that the fretting fatigue endurance limit of the reheat-treated 1Cr-0.5Mo steel decreased about 46% from the non-fretting fatigue endurance limit, while the fretting fatigue endurance limit of the degraded 1Cr-0.5Mo steel decreased about 53% from the non-fretting fatigue endurance limit. The maximum value of fatigue endurance limit difference is observed as 57%(244 MPa) between the fretting fatigue of degraded material and non-fretting fatigue of reheat-treated material. These results can be a basic data to a structural integrity evaluation of heat resisting steel considered to thermal degradation effect.