• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.769-777
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• 2015

In this study, the rheological models were introduced and developed to reflect rate dependent tensile behaviour of concrete. In general, mechanical properties(e.g. strength, elasticity, and fracture energy) of concrete are increased under high loading rates. The strength of concrete shows high rate dependency among its mechanical properties, and the tensile strength has higher rate dependency than the compressional strength. To simulate the rate dependency of concrete, original spring set of RBSN(Rigid-Body- Spring-Network) model was adjusted with viscous and friction units(e.g. dashpot and Coulomb friction component). Three types of models( 1) visco-elastic, 2) visco-plastic, and 3) visco-elasto- plastic damage models) are considered, and the constitutive relationships for the models are derived. For validation purpose, direct tensile test were simulated, and characteristics of the three different rheological models were compared with experimental stress-strain responses. Simulation result of the developed visco-elasto-plastic damage(VEPD) model demonstrated well describing and fitting with experimental results.

• Geomechanics and Engineering
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• v.36 no.2
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• pp.167-181
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• 2024

The soil-structure relative stiffness is a key factor affecting the seismic response of underground structures. It is of great significance to study the soil-structure relative stiffness for the soil-structure interaction and the seismic disaster reduction of subway stations. In this paper, the dynamic shear modulus ratio and damping ratio of an inhomogeneous soft soil site under different buried depths which were obtained by a one-dimensional equivalent linearization site response analysis were used as the input parameters in a 2D finite element model. A visco-elasto-plastic constitutive model based on the Mohr-Coulomb shear failure criterion combined with stiffness degradation was used to describe the plastic behavior of soil. The damage plasticity model was used to simulate the plastic behavior of concrete. The horizontal and vertical relative stiffness ratios of soil and structure were defined to study the influence of relative stiffness on the seismic response of subway stations in inhomogeneous soft soil. It is found that the compression damage to the middle columns of a subway station with a higher relative stiffness ratio is more serious while the tensile damage is slighter under the same earthquake motion. The relative stiffness has a significant influence on ground surface deformation, ground acceleration, and station structure deformation. However, the effect of the relative stiffness on the deformation of the bottom slab of the subway station is small. The research results can provide a reference for seismic fortification of subway stations in the soft soil area.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.09a
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• pp.183-199
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• 2002

Reliability.The reliability strongly depended on the CTE of underfill resin..The fractured portion was identical with the maximum plastic equivalent strain..1 % or less value of the maximum plastic equivalent strain certified more than 1000 cycle of TCT life. UFB.Bonding accuracy was confirmed within2$2{\mu}{\textrm}{m}$..The fundamental bondability of UFB was confirmed with no damage around aluminum pads. Some dislocations and vacancies were observed at the interface, however, the atomic level bonding was confirmed. CBB.Dry process was applied to UBM removal.

• Archives of Reconstructive Microsurgery
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• v.23 no.2
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• pp.93-96
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• 2014

The microscope is a surgical instrument with wide use in plastic surgeries more often than other departments due to the high rate of microscopic surgeries. Unfortunately, because the microscope is used mainly for digital replantations and free flaps, the utilization rate is low compared to the price and usability of the microscope itself. From September 2013 to March 2014, a foreign body which was untraceable with radiology in a patient who desired surgical exploration (one case), and a foreign body which was detected but was smaller than 3 mm (two cases) were removed using the microscope. All foreign bodies, which were fish bone, thin metals, or wooden objects, matching the history of the patients, were completely removed without damage. There were no complications and patient satisfaction was high through follow-up. We have described the microscope as the last and optimal examination tool in removal of micro foreign bodies. A simple change of thought, so that the microscope can be used as a second diagnostic tool will decrease complications by foreign bodies.

• Archives of Plastic Surgery
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• v.33 no.3
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• pp.392-397
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• 2006

Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome(IOIS), may have protean clinical manifestations. IOIS should be determined with a diagnosis of exclusion, with evaluation directed toward eliminating other causes of orbital disease. Orbital MRI and CT are the important diagnostic tests, but serologic studies are necessary to exclude a systemic causes. Biopsy is usually not performed currently, as the risk of producing damage to vital structures within the orbital outweighs the benefits. Patients with multiple recurrences, or those unresponsive to therapy, should be treated of biopsy sample extraction. Corticosteroids are the mainstay of therapy and administered for several months to ensure remission. Radiotherapy may be used in patients who fail to respond to steroids or who have a rapidly progressive course. We analysed the data of two patients. There were no specific complications related to this treatment. We discussed the radiologic findings, treatment procedures, and other orbital diseases.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.525-529
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• 2006

Purpose: Facial nerve injury is a rare but feared complication of face lift. Uncertainty as to the depth and vulnerability of the facial nerve in face lift dissection causes some surgeon, particularly novices, to dissect slowly. Excessively thin flaps can be made because of fear of nerve injury, contributing to skin slough. Methods: From September 1998 to February 2003, the authors operated on 34 aging face patients using classical face-lift. We had analysed about quantity of skin removal and degree of elevated flap. The authors have found quantity of skin removal was 1.5-2.0 cm, degree of elevated flap was 40-45 degree on average. Results: The authors performed preauricular pre-excision face-lift technique on 12 aging face patients from July 2003 to Feburary 2005 based on experienced surgery. This technique reduced fear of dissecting skin flap necrosis and facial nerve injury because of firmly attached pre-auricular skin removed in advance. Conclusions: We easily dissected SMAS without visual field disturbance, nerve damage and reduced operation time and bleeding loss compared to classical face-lift.

• Archives of Plastic Surgery
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• v.51 no.1
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• pp.67-71
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• 2024

Clavicle fractures are frequent injuries accounting for approximately 4% of all fractures in adults with about 35% occurring in the shoulder region among which midshaft fractures are the most common (>66%). Nonsurgical management is the treatment of choice for most clavicle fractures; however, poor functional and aesthetic outcomes may result from nonunion, symptomatic malunion, and aesthetic impairment which are the most common complications. A young woman was referred to our clinic for a "Step Deformity" resulting after primary, nonsurgical treatment of a midshaft clavicle fracture. Residual deformity was corrected with a novel simple and little invasive approach. Midshaft clavicle fractures typically only require conservative nonsurgical treatment, nevertheless suboptimal outcomes may occur. Selective osteotomies and fixation are deemed too invasive when only cosmetic impairment of the clavicle contour is present without any functional or sensitive damage and most patients are discouraged from undergoing surgery. Thus far, no specific focus on this topic, nor exploration of possible correction can be found in the published literature. These residual deformities may be very noticeable sometimes and cause psychological distress and social life impairment. Despite no related functional impairment, this deformity should still be addressed, to improve patients' quality of life.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.190-195
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• 2001

In the present paper computational simulation of a concrete dam is performed to determine the effect of vertical ground motions on earthquake response of concrete dams. Cyclic and dynamic versions of the plastic-damage model proposed by Lee and Fenves are used to represent micro-crack development and crack opening/closing, which is important mechanism in nonlinear damage analysis of concrete structures subject to strong earthquake loading. The result shows that the vertical component of ground motion effects on final crack patterns and consequently, on displacement response.

• Journal of Ship and Ocean Technology
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• v.6 no.3
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• pp.1-12
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• 2002

In this paper the results are reported of sixty-nine lateral collision tests, which were performed to investigate the collision resistance of plates. For the tests a collision testing machine of spring-roller conveyer type was designed and fabricated. Using this machine, various plates were tested with different masses and velocities and various headers of the striker. A simple analytical method has also been developed to predict the extent of damage of struck plates due to lateral collision. In the method, it is assumed that the kinetic energy of the striker can be dissipated by the formation of yield lines and membrane tensions in the impacted plate. The calculated predictions of extent of damage using the developed method have been substantiated with the test results, which shows reasonably acceptable correlations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.530-533
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• 2009

This study deals with 2D and 3D nonlinear seismic damage analysis of a concrete gravity dam using the finite element program ABAQUS and the concrete damaged plasticity model. 2D and 3D spillway sections of the dam are simulated. First the frequency analysis is conducted to compare the fundamental frequency and estimate the value of damping coefficient. Then the seismic analysis is conducted using the simulated ground acceleration motion. The relative displacement between the crest and bottom of the dam is obtained and compared for the maximum value and occurrence time. The results indicate that the plane-stress assumption gives similar results of maximum relative displacement and final damage distribution with 3D analysis.