• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.561-566
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• 2008

Recently, because of development of the high speed train technology, the vibration loads by train is significantly increased ever than before. This buried gas pipelines are exposed to both repeated impact loads, and, moreover, they have been influencing by vibration loads than pipeline which is not located under vehicle loads. The vibration characteristic of pipeline is examined by dynamic analysis, and variable is only train speed. Since an effect of magnitude of vibration loads is more critical than cover depth, as increasing the train speed, the vibration speed of buried pipelines is also increased. The slope of vibration velocity is changed by attenuation of wave, at train speed, 300 km/h. From the analysis results, the vibration velocity of pipelines is satisfied with the vibration velocity criteria which are established by Korea Gas Corporation. The results present operation condition of pipelines under rail loads has fully sound integrity based on KOGAS specification.

• Journal of Korean Society for Quality Management
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• v.43 no.1
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• pp.43-56
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• 2015

Purpose: In this research, We made the conceptual frameworks for SEM(Structural Equation Modeling) on Global quality's origin and empirical research. Developing conceptual frameworks is an important step in theory building and theory testing. This research model was developed by strong theoretical foundation which is quality and systematical model. Methods: Questionnaire was developed, and data was collected and analyzed for this study. The analysis was conducted using SEM(Structural Equation Modeling). Results: Results show that process quality and interaction quality are important drivers in customer satisfaction. Customer satisfaction is strongly impact on customer loyalty(repeated purchase). Conclusion: In turbulent business era, Global company require not only excellent quality but also create customer oriented culture and control over operation in the foreign country.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.87-94
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• 2005

Mating is an essential behavioural social event in the life cycle of silkworm, Bombyx mori (L.) for the perpetuation of population. A number of intrinsic and extrinsic factors and events of significant importance are involved in successful mating and egg deposition by an adult silk moth which besides biochemical, physiological and environmental factors also includes attraction of reproductively competent male and female moth for mating, duration and frequency of mating, age of moth at the time of mating, reuse of male moth in the production of eggs etc. An attempt has been made in this review article to elucidate briefly the behaviour of male towards female moth after eclosion, impact of duration and frequency of mating on egg deposition and oviposition, reuse of mated male moth in the production of quality and quantity eggs etc. in the silk-worm, B. mori and its significance in silkworm seed production.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1376-1385
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• 2017

This paper proposes a method for estimating the expected frequency of voltage swells caused by asymmetrical faults in a power system. Although voltage swell is less common than voltage sag, repeated swells can have severe destructive impact on sensitive equipment. It is essential to understand system performance related to voltage swells for finding optimal countermeasures. An expected swell frequency at a sensitive load terminal can be estimated based on the concept of an area of vulnerability (AOV) and long-term system fault data. This paper describes an effective method for calculating an AOV to voltage swells. Interval estimation for an expected swell frequency is also presented for effective understanding of system performance. The proposed method provides long-term performance evaluation of the frequency and degree of voltage swell occurrences.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.158-164
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• 2003

The air circuit breaker (ACB) with the spring-actuated mechanism was studied to improve the fatigue-proof characteristics of its link. The low-cycle fatigue fracture phenomenon occurred on the critical link, called h-link, of ACB from the repeated rapid closing and opening operations. To analyze the cause of failure, dynamic FE-analysis on the b-link part of ACB was performed considering tile velocity and acceleration of the links per time as boundary conditions, which were obtained by using ADAMS. Also, the S-N curve obtained by experiments was used to investigate requirement on the fatigue-proof characteristics. Then, to reduce the maximum tensile stress on the h-link, three types of h-link were examined and one of them was selected.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1628-1636
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• 2008

Construction of concrete slab track is trending to increase gradually in national and international for reduction in track maintenance cost and secure of ride comfort. But elastic pad becomes superannuated due to repeated train operation. After all, it brings change of pad stiffness and it could directly act on track and bridge as load transmission and impact force. In this study, we carried out laboratory test changing pad stiffness after making a model of 15m bridge and laying concrete slab track. Also, we carried out static and dynamic behaviors test(stress, natural frequency, damping ratio, vibrational acceleration, deflection) of bridge and track and experimentally analyzed them by change of elastic pad stiffness on rail fastener.

• The Korean Journal of Pain
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• v.8 no.2
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• pp.336-340
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• 1995

Impairment of erectile function, although normally a benign disorder, has a profound impact on the well-being of many men. Penile erection is produced by a complex series of events involving cognition, peripheral sensory input, central and peripheral autonomic nervous events and hormonal vascular events. The multiplicity of potential determinants identified suggest that impotence does not inexorably accompany age, but it is an arugmented significantly modifiable paraaging phenomena. A 53 year old male patients developed sudden impotence. The patients did not respond to intracavernous injection of papaverine. This patient was successfuly treated with 4 repeated stellate ganglion blocks.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.344-349
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• 2005

Cast steels have been mainly in rod type couplers which connect railway vehicles. These components, as important members, are exposed to repeat to repeated stresses and impact loading during stop and departure service for a long tie. The coupler suffers fatigue crack initiations and demage that cause need to repair weldment due to these loading conditions. Therefore, the heat affected zone of cast steel couple in rod type were evaluated in view of metallurgical weld characteristics after repair welding at laboratory. The specimens with two different welding techniques were evaluated after several welding conditions and post-heat treatments. Micro-vickers hardness and tensile tests and microstructural observations were conducted on heat affected zone of the weldment according to repair weld and post-heat treatment.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1275-1280
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• 2016

This research is for the visualization of wooden cracking phenomena in the virtual world. Timber supplies has been traditionally used for buildings in the all over the world. Wood has a characteristic that is more prone to be influenced and distorted under the external environments compared with other materials like as stone and concrete. Many related researches say that moisture content change is a largest impact factor for the distortion and crack of timber supplies. This is the reason why we focus on the relationship between the moisture variations and the wood distortion, especially crack. In this research, it is mathematically explained that the diminutions of tensile strength caused by repeated contraction and expansion according to the moisture variations under the changes of weather. Finally, we suggest a way to visualize it for pine timbers.

• The Korean Journal of Gastroenterology
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• v.72 no.5
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• pp.252-257
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• 2018

This guidance is an updated version of the irritable bowel syndrome (IBS) guidelines based on evidence-based medicine. IBS is a common chronic gastrointestinal syndrome that occurs in approximately 10% of the population and causes chronic abdominal pain as well as bowel habit changes, such as stool frequency or consistency. The final diagnosis of IBS is based on the exclusion of organic diseases that would explain the symptoms and the absence of endoscopic abnormalities. IBS can reduce the quality of life and cause a major disease burden, such as repeated examinations and continuous drug use, by mistaking organic diseases including malignancy. The major changes are as follows: 1) when to perform a colonoscopy under the impression of IBS; 2) effect of a low-fermentable oligosaccharides, disaccharides, monosaccharides, and polyol diet; 3) impact of probiotics in IBS; and 4) role of antibiotics in IBS. The Korean Society of Neurogastroenterology and Motility recently updated these guidelines to support physicians for qualified medical services and reduce the socioeconomic burden of IBS.