• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.83-88
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• 2010

Domestic nuclear steam generators with Alloy 600 HTMA tubes have experienced axial cracking at eggcrate tube support plates(TSPs). The axial stress corrosion cracks were observed at the crevice between outside of tubes and eggcrate TSPs. The root cause of axial cracking was investigated by thermal hydraulic analysis and sludge distribution diagnosis. It is suggested that deposition of sludge at eggcrate TSPs could increase the outside surface temperature of tube and promote the enrichment of impurities at crevice, and thus accelerate cracking. Additionally strategy for reducing the sludge ingress to steam generators is discussed.

• 대한기계학회논문집A
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• 제31권7호
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• pp.784-791
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• 2007

Fretting, which is a special type of wear, is defined as small amplitude tangential oscillation along the contacting interface between two materials. In nuclear power plants, fretting wear caused by flow induced vibration (FIV) can make a serious problem in a U-tube bundle in steam generator. In this study, substructure method is developed and is verified the feasibility for the finite element model of fretting wear problems. This method is applied to the two-dimensional finite element analyses, which simulate the contact behavior of actual tube to support. For these examples, computing time can be reduced up to 1/5 in comparisons with conventional finite element analyses.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.196-202
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• 1997

A reinforced hydraulic hoses,caiied a resonator hoses,with fixible metal tube are commonly used in automotive power steering hydraulic systems to attenuate and eliminate the objectionable fluid borne noise(pressure ripple) or vibration produced by a pump or steering gear. To achieve better nose attenuation in automotile vehicles, the investigations on propagation and attenuation characteristics of fluid borne pressure ripple in power steering hydraulic ciruit are required. So, this paper descibes a mathematical model of hydraulic hoses to support design the power steering hydraulic circuit and analyze the attenuation characteristics of flow and pressure ripples. The model is based on the transfer matrix approach. The experimental results show that the pulsation attenuation characteristics of hydraulic house is remarkably affected by the flexible metal tube inserted coaxially inside a hydraulic hose with a finite length as well as viscoelastic properties of house wall. It is also shown that the predicted results bymodel proposed here agree well with the measured results over a wide frequency range. These results will assist in the modeling and design of hydraulic hoses, and hear, should provide a means for designing a quieter automotive power steering hydraulic systems.

• Korea-Australia Rheology Journal
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• 제18권1호
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• pp.9-14
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• 2006

We show that some network and pom-pom constitutive models are essentially the same. Instead of the usual confrontation, we suggest that the two approaches can offer useful mutual support: vital information about network destruction rates found from detailed pom-pom calculations can be used to improve the network models, while deductions about network creation rates can pinpoint areas needing further attention in the tube modelling area. A new form of the PTT model, the PTT-X model, results in improved shear and elongational flow descriptions, plus an improved recoil behaviour. The remaining problems of strain-time separation, second normal stress difference description, and reduction of parameters are also discussed and some suggestions for progress are offered.

• 설비공학논문집
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• 제27권3호
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• pp.174-178
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• 2015

This paper describes a signal processing technique for identifying signals from defects by using an electromagnetic-ultrasonic guided waves method based on a magnetostrictive sensor that generates a torsional mode (T(0, 1)). Because this technique is based on the digital filtering, the filtered signals provide information on the relationship between the cutoff frequency of band-pass filter and the characteristic of defect signals in heat exchange tubes. To verify the performance of the technique, artificial defects with various thickness reduction ration and shape were machined in titanium tubes, and digital filtering results are reported. The results show that digital filtering provides information to the identify shape of defects and the contact condition between the tube and support ring. Therefore, the proposed technique has good potential as a tool for evaluating the integrity of heat exchange tubes.

• 한국정밀공학회지
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• 제27권3호
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• pp.111-117
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• 2010

The repeated unit cell structure is applied to the composite, the carbon nano tube and sandwich panel. In this paper, a study on the stiffness of unit cell structure has been performed with the tube support plate of the steam generator. For this, repeated unit cell structure's equivalent elastic constant and poisson's ratio was evaluated through FEA and tests under the elastic range load. Also we evaluated the effect on the specimen size from results.

• Journal of Chest Surgery
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• 제21권1호
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• pp.191-195
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• 1988

Chylothorax in the neonatal period is a rare cause of respiratory distress. Surgical ligation of the thoracic duct is rarely necessary in congenital chylothorax. A 3 day-old newborn delivered by the cesarean section showed signs of respiratory distress suddenly and diagnosed as chylothorax on the right hemithorax. Conservative management such as multiple thoracenteses and tube thoracostomy drainage with nutritional support failed to close the leakage. At age of 60 days, we performed a supradiaphragmatic mass ligature of the thoracic duct visualized after injection of methylene blue into the thigh subcutaneously. Postoperatively, chylous effusion occurred in the left hemithorax and successfully treated with chest tube drainage for several days.

• Journal of Trauma and Injury
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• 제27권3호
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• pp.75-78
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• 2014

Hypopharyngeal perforation is a rare, but fatal, complication. Clinical signs and symptoms of this condition are neck pain, odynophagia, dysphagia, fever, vomiting, cervical swelling and subcutaneous emphysema. However, these signs are obscured in patient suffering from severe trauma who has had an endotracheal tube inserted, which delay proper evaluation and treatment. Here, we report a case of hypopharyngeal perforation in a trauma patient who had an endotracheal tube inserted for mechanical ventilation.

• 셀메드
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• 제12권2호
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• pp.8.1-8.2
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• 2022

The Yangbanchum was reconstructed based on mask play that had been handed down in Goseong, Gyeongsangnam-do, Korea. Talnori, called Goseong Ogwangdae, is a Korean folk cultural heritage designated as National Important Intangible Cultural Property No. 57. This mask play provides catharsis to the audience by unraveling the hypocrisy and lies of the aristocrats through satire and humor. Our performance team, the ensemble Better Than Medicine (eBTM) used a large fan (Boochae)to create a performance that blew away anxiety and pain. Watching this performance, the performer and the audience feel the consensus of sharing emotions and send strong bonds and support to each other. This study provides that Yangbanchum dance promotes the mental health by feeling emotional sharing through vicarious satisfaction and mirror effect.

• 대한조선학회논문집
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• 제42권5호
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• pp.479-486
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• 2005

The final goal of shift alignment design is that the bearing reaction forces or mean pressures are within design boundaries for various service conditions of a ship. However, it is found that calculated bearing load can be substantially variable according to the locations of the effective support points of after sterntube bearing which are determined by simple calculation or assumption suggested by classification societies. A new analysis method for shaft alignment calculation is introduced in order to resolve these problems. Key concept of the new method is featured by adopting both nonlinear elastic and multi-support elements to simulate a bearing support Hertz contact theory is basically applied for nonlinear elastic stiffness calculation instead of the projected area method suggested by most of classification societies. Three loading conditions according to the bearing offset and the hydrodynamic moment and twelve models according to the locations of the effective support points of sterntube bearings are prepared to carry out quantitative verifications for an actual shafting system of 8000 TEU class container vessel. It is found that there is relatively large difference between assumed and calculated effective support points.