• Journal of Chest Surgery
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• v.17 no.4
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• pp.687-690
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• 1984

Aortic dissection, a condition characterized by hemorrhage into the media and variable extension along the length of the aorta, has long been recognized as a catastrophic Cardiovascular event. Recent developments in diagnostic and therapeutic skills have improved the prognosis considerably, but there is still controversy as to how cases should be managed. We experienced a case of dissecting aortic aneurysm [DeBakey Type III ], which were managed using intensive medical treatment. The period of follow up was about 11 years. At last, patient was died by progression of dissection into proximal aorta and resulted in aortic insufficiency and congestive heart failure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.82-85
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• 1997

This paper describes the development of new type arrester for 22.9kV class distribution lines, with polymer insulating materials applied to their housings. The new arrester employs silicone insulating material for its housing, instead of the conventional porcelain housing, aiming at reduction in size and weight and explosion proof against internal short circuit failure. And, since the design of sheds is not restricted. it is possible to provide a long surface leakage distance per strike length and improve anti-contamination performance.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.165-168
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• 2005

Carbon Fiber Reinforced Polymer(CFRP) composites are widely applied to strengthen deteriorated concrete structures. This paper presents the experimental results of the performance of reinforced concrete(RC) decks strengthened with CFRP composites. Simple span decks with 2m span length were tested to investigate the effect of CFRP reinforcement types on the flexural behavior of strengthened RC beams. The test results were analyzed with the special emphasis on the failure mode and the maximum load.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.306-309
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• 2006

The fully embedded composite truss beam is developed based on composite member, truss system before composite and beam system after composite. The proper design concept and method of the fully embedded composite truss beam are discussed. A bending test on the fully embedded composite truss beam with span length 25.0m is carried out to investigate the flexural behavior and ultimate strength of the developed structure up to failure. A good agreement between the measured and predicted results are observed.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.201-206
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• 1993

Four reinforced concrete beams without shear reinforcement were tested statically up to failure to investigate the arch action in reinforced concrete beams. Major variable was the shear span to depth ratio varied from 2 to 4. Due to the reduction of internal moment arm length by the development of arch action, the measured steel tension was higher than the calculated steel tension.

• Journal of Korean Society for Quality Management
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• v.15 no.1
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• pp.13-19
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• 1987

This paper discusses the methods of determining optimal warranty period for repairable goods. The demand of the product is assumed to increase with the length of the warranty period. Good-as-new repair and minimal repair models are considered. The method of obtaining optimal warranty period is explored when the failure distribution is an exponential or a Weibull. The case of discounting all associated costs continuously over time is also considered.

• Journal of the Korean Institute of Telematics and Electronics
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• v.7 no.4
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• pp.67-82
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• 1970

In this paper, formulas are developed for computing induced line voltages incommunication lines due to power line failure. Formulas are expressed in terms of fault current, mutual impedance andlength of line. Computed results are shown for various power line valtages and length of line. (Computation is done by IBM 1130-3B Computer system at Soong Sil Compute Center)

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.4
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• pp.387-400
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• 2013

In this study, the slope stability analysis and the landslide hazard assessment in tunnel portal slope were carried out. First, we selected highly vulnerable areas to slope failure using the slope stability analysis and analyzed the slope failure scale. According to analyses results, high vulnerable area to slope failure is located at 485~495 m above sea level. The slope is stable in a dry condition, while it becomes unstable in rainfall condition. The analysis results of slope failure scale show that the depth of slope failure is maximum 2.1 m and the length of slope failure is 18.6 m toward the dip direction of slope. Second, we developed a 3-D simulation program to analyze characteristics of runout behavior of debris flow. The developed program was applied to highly vulnerable areas to slope failure. The result of 3-D simulation shows that debris flow moves toward the central part of the valley with the movement direction of landslide from the upper part to the lower part of the slope. 3-D simulation shows that debris flow moves down to the bottom of mountain slope with a speed of 7.74 m/s and may make damage to the tunnel portal directly after 10 seconds from slope failure.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.149-153
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• 2000

Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and specific strength of composite materials. In this work, one-piece propeller shafts composed of carbonfepoxy and glass/epoxy composites were designed and manufactured for a rear wheel drive automobile satisfying three design specifications, such as static torque transmission capability, torsional buckling and the fundamental natural bending frequency. Single lap adhesively bonded joint was employed to join the composite shaft and the aluminum yoke. For the optimal adhesive joining of the composite propeller shaft to the aluminum yoke, the torque transmission capability of the adhesively bonded composite shaft was calculated with respect to bonding length and yoke thickness by finite element method and compared with the experimental result. Then an optimal design method was proposed based on the failure model which incorporated the nonlinear mechanical behavior of aluminum yoke and epoxy adhesive. From the experiments and FEM analyses, it was found that the static torque transmission capability of composite propeller shaft was maximum at the critical yoke thickness, and it saturated beyond the critical length. Also, it was found that the one-piece composite propeller shaft had 40% weight saving effect compared with a two-piece steel propeller shaft.

• Structural Engineering and Mechanics
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• v.5 no.4
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• pp.355-368
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• 1997

Fiber reinforced plastic (FRP) rods are used as reinforcement (prestressed or not) to concrete. FRP composites can also be combined with steel to form hybrid reinforcing rods that take advantage of the properties of both materials. In order to effectively utilize these rods, their bond behavior with concrete must be understood. The objective of this study is to characterize and model the bond behavior of hybrid FRP rods made with epoxy-impregnated aramid or poly-vinyl alcohol FRP skins directly braided onto a steel core. The model closely examines the split failure of the concrete by quantifying the relationship between slip of the rods resulting transverse stress field in concrete. The model is used to derive coefficients of friction for these rods and, from these, their development length requirements. More testing is needed to confirm this model, but in the interim, it may serve as a design aide, allowing intelligent decisions regarding concrete cover and development length. As such, this model has helped to explain and predict some experimental data from concentric pull-out tests of hybrid FRP rods.