• Computers and Concrete
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• 제19권3호
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• pp.315-323
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• 2017

Within the context of continuum mechanics, inelastic behaviours of constitutive responses are usually modelled by using phenomenological approaches. Elasto-plastic damage modelling is extensively used for concrete material in the case of progressive strength and stiffness deterioration. In this paper, a review of the main features of elasto-plastic damage modelling is presented for uniaxial stress-strain relationship. It has been reported in literature that the influence of Alkali-Silica Reaction (ASR) can lead to severe degradations in the modulus of elasticity and compression strength of the concrete material. In order to incorporate the effects of ASR related degradation, in this paper the constitutive model of concrete is based on the coupled damage-plasticity approach where degradation in concrete properties can be captured by adjusting the yield and damage criteria as well as the hardening moduli related parameters within the model. These parameters are adjusted according to results of concrete behaviour from the literature. The effect of ASR on the dynamic behaviour of a beam and a column are illustrated under moving load and cyclic load cases.

• 대한두개안면성형외과학회지
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• 제21권3호
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• pp.202-205
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• 2020

Trichoepithelioma is a benign hair follicle tumor that can undergo malignant transformation into basal cell carcinoma in rare cases. Due to the similar clinical and histological features of trichoepithelioma and basal cell carcinoma, distinguishing between these types of tumors can be a diagnostic challenge. Punch biopsy obtains only a small sample of the entire lesion, and thus inherently involves a risk of misdiagnosis between histologically similar diseases. Therefore, if the possibility of misdiagnosis can reasonably be suspected, clinicians should conduct an excisional biopsy or immunohistochemical staining (e.g., CD10 and Bcl-2) to ensure an exact diagnosis. Although trichoepithelioma is benign, the surgical excision of solitary trichoepithelioma should be considered in order to avoid the possibility of malignant transformation, which has occasionally been documented for multiple familial trichoepitheliomas. Herein, we report a case that was initially misdiagnosed as trichoepithelioma before ultimately being diagnosed as basal cell carcinoma through excision and immunohistochemical staining.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.45-51
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• 2012

Multilayer co-extrusion blown film construction is a popular technique for producing plastic films for various packaging industries. Automated detection of defective films can improve the quality of film production process. In this paper, we propose a film inspection system that can detect and classify film defects robustly. In our system, first, film images are acquired through a high speed line-scan camera under an appropriate lighting system. In order to detect and classify film defects, an inspection algorithm is developed. The algorithm divides the typical film defects into two groups: intensity-based and texture-based. Intensity-based defects are classified based on geometric features. Whereas, to classify texture-based defects, a texture analysis technique based on local binary pattern (LBP) is adopted. Experimental results revealed that our film inspection system is effective in detecting and classifying defects for the multilayer co-extrusion blown film construction line.

• Advances in concrete construction
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• 제1권1호
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• pp.103-119
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• 2013

The applicability of limit analysis methods in design and assessment of concrete structures generally requires a certain plastic deformation capacity. The latter is primarily provided by the ductility of the reinforcement, being additionally affected by the bond properties between reinforcing steel and concrete since they provoke strain localization in the reinforcement at cracks. The bond strength of reinforcing bars is not only governed by concrete quality, but also by construction details such as bar ribbing, bar spacing or concrete cover thickness. For new concrete structures, a potentially unfavorable impact on bond strength can easily be anticipated through appropriate code rules on construction details. In existing structures, these requirements may not be necessarily satisfied, consequently requiring additional considerations. This two-part paper investigates in a theoretical study the impacts of the most frequently encountered construction details which may not satisfy design code requirements on bond strength, steel strain localization and plastic deformation capacity of cracked structural concrete. The first part introduces basic considerations on bond, strain localization and plastic deformation capacity as well as the fundamentals of the Tension Chord Model underlying the further investigations. It also analyzes the impacts of the hardening behavior of reinforcing steel and concrete quality. The second part discusses the impacts of construction details (bar ribbing, bar spacing, and concrete cover thickness) and of additional structure-specific features such as bar diameter and crack spacing.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.220-227
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• 2002

This study introduces the fragility analysis method for the safety evaluation of reinforced concrete pier subject to earthquake. Damage probability is calculated instead of the failure probability from definition of the damage state in the fragility curve. Not only the damage model determined by the response of structure subject to earthquake, but also the plastic-damage model which can represent the local damage is applied to fragility analysis. The evaluation method of damage state by damage variable in global structure is defined by this procedure. This study introduces the fragility analysis method considering the features of nonlinear time history behavior of reinforced concrete element and the plastic behavior of materials. At last, This study gives one of the approach method for seismic margin evaluation with the result of fragility analysis to design seismic load.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권2호
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• pp.279-285
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• 1996

The odontogenic keratocyst(OKC) was used of term and described some of clinical, radiological and microscopic features by Philipsen 1956. The microscopic finding of OKC is characterized by the production of keratin, Which sometimes fills the lumen and thinning of epithelium of cyst. The most clinical importance of OKC is its extraordinary recurrence rate owing to the incomplete removal of the cyst wall. The final diagnosis of OKC should be evaluated by histologic findings and follow-up of any case of OKC with annual roentgenograms and clinical evaluations is essential for at least five years after surgery. This article is report of 2 cases of large OKC involved both molar portion and symphysis of mandible with facial asymmetry, severe bone destruction and paresthesia of lower lip on clinically, roentgenographically. By the postoperative findings the patients showed normal regeneration of bone defect area without recurrence signs by panorama films after surgery.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.85-87
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• 2012

We present a numerical investigation on gaseous (ethylene-air mixture) detonation in the elastoplastical metal tubes to understand the wall effects associated with the developing detonation instability. The acoustic disturbances originating from the rapidly expanding tube walls reach the detonating flame surface, thereby causing flame distortions and total energy losses. The compressible Navier-Stokes equations with equation of state for gas and elasto-plastic deformation field equations for inert tubes are solved simultaneously to understand the complex multi-material interaction in the rapidly expanding gas pipe. In order to track governing variables across the material interface, we use the hybrid particle level-set and ghost fluid methods to precisely estimate the interfacial quantities. Features observed from the deforming (thin) tube show substantially different behavior when a detonation propagates in the rigid (thick) tube with no acoustically responding wall conditions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권1호
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• pp.15-20
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• 2001

For the earlier diagnosis and treatment of delayed wound healing in extraction socket, we investigated the clinical, radiographic and histopathologic features of 106 patients with delayed wound healing diagnosed by biopsy. The patients were enrolled at the Department of Oral Pathology, Chosun University Dental Hospital. Among 106 delayed wound healing diagnosed by biopsy, cysts showed most significant 25 cases (23%), osteomyelitis showed 13 cases (12%), chronic maxillary sinusitis and squamous cell carcinoma showed 12 (11%) and 11 (10%) cases, respectively. We have analyzed these lesions through relevant literatures.

• Structural Engineering and Mechanics
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• 제5권5호
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• pp.587-598
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• 1997

A numerical model for masonry is proposed by following an internal variable approach originally developed in the field of elastic-plastic analysis. The general features of the theoretical framework are discussed by focussing on finite element models applicable to incremental elastic-plastic problems. An extremum property is derived and its implications in terms of convergence for convenient algorithms are briefly discussed, by including the case of softening materials and damage effects. Next, a numerical model is presented, which is suitable for masonry, can be developed according to the same internal variable formulation and enjoys similar properties. Some numerical results are presented and compared with the response of a masonry shear wall subjected to pseudodynamic tests.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권6호
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• pp.531-534
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• 2009

Dermoid cysts located in the floor of the mouth are very rare developmental keratinizing squamous epithelium lined cysts. Anatomically, they are classified as sublingual (median genioglossal), submental (median geniohyoid) and lateral dermoid cysts, and they can be further classified as epidermoid, dermoid, and teratoid cysts by histology. We report a case of sublingual dermoid cyst in a 16-year-old boy presenting as a large sublingual swelling causing speech and swallowing difficulties and discuss the surgical treatment techniques and histopathological features of this lesion.