• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.45-50
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• 2001

Fuzzy theory is used to quantify some subjective criteria and consider uncertain factors for transmission line reinforcement planning in this paper. Sugeno's fuzzy integral is also used in the proposed method, because it can be easily allied to multi attribute decision making problems such as power system planning. To verify the proposed algorithm, some bode-neck lines are searched for the case that the amount of Maximal Load Supplying Capability(MLSC) is small using the results of contingency analysis for Korea Electric Power Corporation(KEPCO)'s 345[kV] transmission line in 1998. And several feasible alternatives are composed for line reinforcement which can dissolve the bottle-neck.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.136-142
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• 2015

Objectives: The aim of this study was to evaluate the effects of tri-antibiotic paste (TAP) on microtensile bond strengths (MTBS) of dental adhesives to dentin. Materials and Methods: Sixty extracted molars had their occlusal surfaces flattened to expose dentin. They were divided into two groups, i.e., control group with no dentin treatment and experimental group with dentin treatment with TAP. After 10 days, specimens were bonded using self-etch (Filtek P90 adhesive) or etch-and-rinse (Adper Single Bond Plus) adhesives and restored with composite resin. Teeth were sectioned into beams, and the specimens were subjected to MTBS test. Data were analyzed using two-way ANOVA and post hoc Tukey tests. Results: There was a statistically significant interaction between dentin treatment and adhesive on MTBS to coronal dentin (p = 0.003). Despite a trend towards worse MTBS being noticed in the experimental groups, TAP application showed no significant effect on MTBS (p = 0.064). Conclusions: The etch-and-rinse adhesive Adper Single Bond Plus presented higher mean bond strengths than the self-etch adhesive Filtek P90, irrespective of the group. The superior bond performance for Adper Single Bond when compared to Filtek P90 adhesive was confirmed by a fewer number of adhesive failures. The influence of TAP in bond strength is insignificant.

• Polymer(Korea)
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• v.24 no.3
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• pp.326-332
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• 2000

The effects of sizing agent on the final mechanical properties of the glass fiber/unsaturated polyester composites were investigated by contact angle measurements at room temperature. In this work, glass fibers were coated by poly(vinyl alcohol), polyester, and epoxy type sizing agent and each property was compared. Contact angles of the sized glass fiber were measured by the wicking method based on Washburn equation using deionized water and diiodomethane as testing liquids. As an experimental result, the surface free energy calculated from contact angle showed the highest value in case of the glass fiber coated by epoxy sizing agent. From measurements of interlaminar shear strength (ILSS) and fracture toughness ( $K_{IC}$ ) of the composites, it was found that the sizing treatment on fibers could improve the fiber/matrix interfacial adhesion, resulting in growing the final mechanical properties. This was due to the enhanced surface free energy of glass fibers in a composite system.

• Archives of Plastic Surgery
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• v.38 no.4
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• pp.465-471
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• 2011

Purpose: Blepharoptosis is often associated with telecanthus and the presence of epicanthal fold in telecanthus is one of unique features in Asian eyelids. The purpose of this article is to define telecanthus and pseudotelecanthus, and to determine optimal surgical procedure depending on classification of telecanthus. Methods: Among 187 patients with blepharoptosis who had the advancement procedure of the Muller's musclelevator aponeurosis composite flap for ptosis, 55 patients underwent Flowers' split V-W plasty concomitantly with shortening the medial canthal tendon for correction of telecanthus from September 2003 to January 2011. Among them, 52 patients were followed up for 16 months. We newly defined telecanthus because Mustarde ratio is inaccurate to measure in certain cases and then made a definition of pseudotelecanthus. Besides, we also classified telecanthus into mild, moderate and severe types based on its severity. Results: Telecanthus is defined when the ICD (inner canthal distance) is greater than 110% of normal ICD. Pseudotelecanthus is a telecanthus like a wide skin bridge formed between the eyes because of the epicanthal fold in the normal ICD. Flowers' split V-W plasty combined with shortening medial canthal tendon was very effective in mild and moderate telecanthus with almost invisible scar and no recurrence occurring. In severe types, however, it showed high incidence (28%) of incomplete correction of telecanthus. Conclusion: New definition of telecanthus can be easily applied to any case and we think the classification of telecanthus is useful to select an appropriate operative procedure. Split V-W plasty with shortening of medial canthal tendon is a very effective procedure in mild and moderate telecanthus. Besides, it is also effective in improving the treatment outcomes of ptosis in cases of blepharoptosis associated with telecanthus.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.571-577
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• 2009

Purpose: The Provision of thin and pliable tissue and the adequate coverage of tendon - gliding surface is necessary for a soft tissue defect of the hand with exposure of bone, tendon and muscle. This report will discuss our experience with anterolateral thigh fascial free flap for the reconstruction of the soft tissue defect of the hand. Methods: Between February 2004 and August 2008, seven patients with full - thickness soft tissue defects of the hand were reconstructed by means of a composite anterolateral thigh fascial free flap. There were soft tissue defects associated with trauma (n=5), scar contracture (n=1) and necrosis due to ischemia (n=1). Flaps were harvested from the anterolateral thigh as adipofascial flaps with only a small sheet of fascia and fatty tissue above it. The fascia and the skin of the donor site was closed directly and delayed split - thickness skin graft was performed. Result: All flaps survived completely. The size of the transferred flap ranged from $2{\times}4cm$ to $5{\times}8cm$. Thin flap coverage was possible without secondary debulking operations. It left minimal donor site morbidity with a linear scar. In one case, the thigh muscle herniation in the donor site was developed. Conclusion: The anterolateral thigh fascial free flap provided thin and pliable tissue which can establish a tendon - gliding mechanism, minimal bulk, minimal donor site morbidity. The disadvantages of this technique were the need for a skin graft and the muscle herniation of donor site.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.182-189
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• 2010

The strengthening performance of FRPs(Fiber Reinforced Polymers) is directly affected by the environmental conditions such as freezing-thawing and moisture because FRPs are usually bonded on the concrete surface. It is, therefore, strongly required to evaluate a durability of bond between FRPs and concrete as well as FRP materials itself. The freezing-thawing resistance of FRPs is evaluated in this study with the variables of freezing-thawing conditions, types of FRP and freezing-thawing cycles. From the test results, it is found that tensile strength and pull-off strength of CFRP are not affected by the freezing-thawing. On the other hands, those of GFRP show a little degradation because of continuous water immersion during thawing process. But, cautions are needed on the bond durability between FRPs and concrete in case of continuous water supplying from adjacent to the concrete.

• Archives of Craniofacial Surgery
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• v.12 no.1
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• pp.48-52
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• 2011

Purpose: Many advances have been made in lower eyelid reconstruction surgical procedures after tumor ablative therapy. These include skin grafts, local flaps, free flaps, and skin expansion. When a full-thickness defect of the lower eyelid is reconstructed with many free flaps, ectropion and deformity of the medial and lateral canthal areas are common late complications caused by gravitational descent. The radial forearm free flap is widely used because of its lack of bulk, ease of dissection, malleability, and hairlessness. This report introduces a novel method for preventing ectropion using a composite radial forearm free flap reconstruction and palmaris longus suspension technique. Methods: A 70-year-old man had a malignant melanoma on his left lower eyelid. The patient was referred to our department after a biopsy confirmed the initial diagnosis. A full-thickness wide resection with a 25 mm free margin was performed, and a $5{\times}8cm$ radial forearm flap was elevated with a vascularised palmaris longus tendon. The palmaris longus tendon was fixed to the medial and lateral orbital rim perisoteum and the deep temporal fascia. The buccal mucosa was grafted to reconstruct the inner conjunctival layer. The pedicle vessels were anastomosed to the left superficial temporal artery and vein. Results: The postoperative clinical course was uneventful. The flap showed good texture and color match. No ectropion was noted 14 months after surgery and the tumor did not recur. The patient was quite satisfied with the final outcomes. Conclusion: Use of a radial forearm free flap and the palmaris longus tendon is an effective method for a full-thickness lower eyelid reconstruction.

• Archives of Craniofacial Surgery
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• v.12 no.2
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• pp.111-115
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• 2011

Purpose: Reconstruction of a full thickness defect of the nose is a difficult task for plastic surgeons because the anatomical characteristic, shape, and function of the nose all need to be taken into consideration. Most often, a local flap or a composite graft is used, but for a large defect, reconstruction using free flaps is the most ideal method. In free flap reconstruction, the chondrocutaneous preauricular area can be a suitable donor site. We performed a chondrocutaneous preauricular free flap with an interpositional vascular graft for reconstruction of a nasal ala. Methods: A 46 year-old male presented to the hospital with a right alar deformity induced by a dog bite. During the surgery, the existing scar tissue was removed and thereby a newly formed full thickness defect was reconstructed using the chondrocutaneous preauricular free flap with an interpositional vascular graft harvested from the descending branch of the lateral femoral circumflex vessel between the facial and superficial temporal vessels of the free flap. Results: The flap survived without flap loss and showed symmetry in its overall shape, contour, texture, and color. The patient was satisfied with the results and the surgery yielded no additional scars at the nasolabial fold area. Conclusion: The chondrocutaneous preauricular free flap is a valuable method in reconstruction of full thickness defects of the nose, and using the descending branch of the lateral femoral circumflex vessel as the interpositional vascular graft at the anastomotic site produces reliable results.

• Steel and Composite Structures
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• v.34 no.2
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• pp.215-226
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• 2020

The aim of this study is to investigate free vibration of functionally graded porous nanocomposite rectangular plates where the internal pores and graphene platelets (GPLs) are distributed in the matrix either uniformly or non-uniformly according to three different patterns. The elastic properties of the nanocomposite are obtained by employing Halpin-Tsai micromechanics model. The GPL-reinforced plate is modeled using a semi-analytic approach composed of generalized differential quadrature method (GDQM) and series solution adopted to solve the equations of motion. The proposed rectangular plates have two opposite edges simply supported, while all possible combinations of free, simply supported and clamped boundary conditions are applied to the other two edges. The 2-D differential quadrature method as an efficient and accurate numerical tool is used to discretize the governing equations and to implement the boundary conditions. The convergence of the method is demonstrated and to validate the results, comparisons are made between the present results and those reported by well-known references for special cases treated before, have confirmed accuracy and efficiency of the present approach. New results reveal the importance of porosity coefficient, porosity distribution, graphene platelets (GPLs) distribution, geometrical and boundary conditions on vibration behavior of porous nanocomposite plates. It is observed that the maximum vibration frequency obtained in the case of symmetric porosity and GPL distribution, while the minimum vibration frequency is obtained using uniform porosity distribution.

• Steel and Composite Structures
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• v.33 no.4
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• pp.509-523
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• 2019

In the present work, the buckling analysis of micro sandwich plate with an isotropic/orthotropic cores and piezoelectric/polymeric nanocomposite face sheets is studied. In this research, two cases for core of micro sandwich plate is considered that involve five isotropic Devineycell materials (H30, H45, H60, H100 and H200) and an orthotropic material also two cases for facesheets of micro sandwich plate is illustrated that include piezoelectric layers reinforced by carbon and boron-nitride nanotubes and polymeric matrix reinforced by carbon nanotubes under temperature-dependent and hydro material properties on the elastic foundations. The first order shear deformation theory (FSDT) is adopted to model micro sandwich plate and to apply size dependent effects from modified strain gradient theory. The governing equations are derived using the minimum total potential energy principle and then solved by analytical method. Also, the effects of different parameters such as size dependent, side ratio, volume fraction, various material properties for cores and facesheets and temperature and humidity changes on the dimensionless critical buckling load are investigated. It is shown from the results that the dimensionless critical buckling load for boron nitride nanotube is lower than that of for carbon nanotube. It is illustrated that the dimensionless critical buckling load for Devineycell H200 is highest and lowest for H30. Also, the obtained results for micro sandwich plate with piezoelectric facesheets reinforced by carbon nanotubes (case b) is higher than other states (cases a and c).The results of this research can be used in aircraft, automotive, shipbuilding industries and biomedicine.