• Steel and Composite Structures
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• v.1 no.1
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• pp.145-158
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• 2001

An experimental study was conducted to evaluate the effects of loading sequence and lateral bracing on the behavior of reduced beam section (RBS) steel moment frame connections. Four full-scale moment connections were cyclically tested-two with a standard loading history and the other two with a near-fault loading history. All specimens reached at least 0.03 radian of plastic rotation without brittle fracture of the beam flange groove welds. Two specimens tested with the nearfault loading protocol reached at least 0.05 radian of plastic rotation, and both experienced smaller buckling amplitudes at comparable drift levels. Energy dissipation capacities were insensitive to the types of loading protocol used. Adding a lateral bracing near the RBS region produced a higher plastic rotation; the strength degradation and buckling amplitude were reduced. A non-linear finite element analysis of a one-and-a-half-bay beam-column subassembly was also conducted to study the system restraint effect. The study showed that the axial restraint of the beam could significantly reduce the strength degradation and buckling amplitude at higher deformation levels.

• Archives of Plastic Surgery
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• v.48 no.1
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• pp.69-74
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• 2021

Background In inferomedially rotated zygomatic fractures sticking in the maxillary sinus, it is often difficult to achieve complete reduction only by conventional intraoral reduction. We present a new intraoral reduction technique using a Kirschner wire and its clinical outcome. Methods Among 39 inferomedially impacted zygomatic fractures incompletely reduced by a simple intraoral reduction trial with a bone elevator, a Kirschner wire (1.5 mm) was vertically inserted from the zygomatic body to the lateral orbital rim in 17 inferior-dominant rotation fractures and horizontally inserted to the zygomatic arch in nine medial-dominant and 13 bidirectional rotation fractures. A Kirschner wire was held with a wire holder and lifted in the superolateral or anterolateral direction for reduction. Following reduction of the zygomaticomaxillary fracture, internal fixation was performed. Results Fractures were completely reduced using only an intraoral approach with Kirschner wire reduction in 33 cases and through an additional lower lid or transconjunctival incision in six cases. There were no surgical complications except in one patient with undercorrection. Postoperative 6-month computed tomography scans showed complete bone union and excellent bone alignment. Four patients experienced difficulty with upper lip elevation; however, these problems spontaneously resolved after manual tissue lump massage and intralesional steroid (Triamcinolone) injection. Conclusions We completely reduced infraorbital rim fractures, zygomaticomaxillary buttresses, and zygomaticofrontal suture fractures in 84% of patients through an intraoral approach alone. Intraoral Kirschner wire reduction may be a useful option by which to obtain effective and powerful reduction motion of an inferomedially rotated zygomatic body.

• Earthquakes and Structures
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• v.16 no.6
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• pp.691-704
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• 2019

This study simulates the responses of large-scale bridge piers under pseudo-dynamic tests to investigate the performance of four types of numerical models that consider the nonlinear behavior of the pier and the rocking behavior of the footing. In the models, beam-column elements with plastic hinges are used for the pier, two types of foundation models (rotational spring and distributed spring models) are adopted for the footing behavior, and two types of viscous damping models (Rayleigh and dashpot models) are applied for energy dissipation. Results show that the nonlinear pier model combined with the distributed spring-dashpot foundation model can reasonably capture the behavior of the piers in the tests. Although the commonly used rotational spring foundation model adopts a nonlinear moment-rotation property that reflects the effect of footing uplift, it cannot suitably simulate the hysteretic moment-rotation response of the footing in the dynamic analysis once the footing uplifts. In addition, the piers are susceptible to cracking damage under strong seismic loading and the induced plastic response can provide contribution to earthquake energy dissipation.

• Steel and Composite Structures
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• v.22 no.1
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• pp.141-159
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• 2016

Commonly in steel frames, steel beam and concrete slab are connected together by shear keys to work as a unit member which is called composite beam. When a composite beam is subjected to positive bending, flexural strength and stiffness of the beam can be increased due to "composite action". At the same time despite these advantages, composite action increases the strain at the beam bottom flange and it might affect beam plastic rotation capacity. This paper presents results of study on the rotation capacity of composite beam connected to Rectangular Hollow Section (RHS) column in the steel moment resisting frame buildings. Due to out-of-plane deformation of column flange, moment transfer efficiency of web connection is reduced and this results in reduction of beam plastic rotation capacity. In order to investigate the effects of width-to-thickness ratio (B/t) of RHS column on the rotation capacity of composite beam, cyclic loading tests were conducted on three full scale beam-to-column subassemblies. Detailed study on the different steel beam damages and concrete slab damages are presented. Experimental data showed the importance of this parameter of RHS column on the seismic behavior of composite beams. It is found that occurrence of severe concrete bearing crush at the face of RHS column of specimen with smaller width-to-thickness ratio resulted in considerable reduction on the rate of strain increase in the bottom flange. This behavior resulted in considerable improvement of rotation capacity of this specimen compared with composite and even bare steel beam connected to the RHS column with larger width-to-thickness ratio.

• Archives of Plastic Surgery
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• v.36 no.1
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• pp.38-45
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• 2009

Purpose: The congenital muscular torticollis is a neck deformity involving shortening of the sternocleidomastoid muscle, which is detected at birth or shortly after birth. This childhood disease is the third most common congenital musculoskeletal anomaly. The indication for surgery is a persistent head tilt with dificit of passive rotation and lateral bending of the neck and a tight band or tumor in the sternocleidomastoid muscle even after physical therapy. The purpose of this article is to report surgical outcomes with patients who had no or little response to physical therapy. Methods: Surgery was performed on 29 patients and their average age was 4.1 years (from 6 months to 20.1 years). The unipolar open release and partial myectomy were done in 28 cases and the muscle lengthening was done in 1 case. Physical therapy was started from postoperative seventh day. Follow - up period was ranged from 2 months to 5.4 years(mean follow - up, 20.4 months). Result: There were neither rotation nor lateral bending deficit after surgical treatment. Mild head tilt was noticed in 3 cases and residual bend was observed in 4 cases. The subjective assessments of surgical results by parents were excellent. Conclusion: Our surgical outcome encourages the surgical treatment of congenital muscular torticollis for patients who failed to respond to physical therapy.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.5
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• pp.51-60
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• 2009

To secure the structural safety of structures and members against earthquakes, the plastic deformation capacity demand of members should be accurately predicted. In the present study, a method for the evaluation of the plastic deformations of members for moment frames was developed. To facilitate the practical use of the proposed method in equivalent seismic design, the plastic deformations of members were evaluated based on the results of elastic analysis, without using nonlinear analysis. The plastic deformation demands of members were formulated as functions of story drift demand, redistributed moment and member stiffness. Story drift demand and moment redistribution were directly determined from elastic analysis. The proposed method was applied to an 8 story-2 bay moment frame, and the predicted plastic deformations were verified using nonlinear analysis. The results showed that the proposed method could be used to accurately predict the member plastic rotations with simple calculations. The proposed method can be applied both to the earthquake design of new structures and to the performance evaluation of existing structures.

• Archives of Plastic Surgery
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• v.46 no.4
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• pp.330-335
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• 2019

Background The use of anatomic implants has improved the aesthetic results of breast surgery; however, implant malrotation is an uncommon, but serious complication of these procedures. Nevertheless, little research has explored implant adhesion. In this study, we investigated adhesion between the expander and the capsule. Methods Seventy-nine cases of immediate breast reconstruction via two-stage implant-based reconstruction performed between September 2016 and November 2017 were evaluated. Mentor CPX4 expanders were used in 14 breasts, and Natrelle expanders in 65. We analyzed areas of adhesion on the surfaces of the tissue expanders when they were exchanged with permanent implants. We investigated whether adhesions occurred on the cephalic, caudal, anterior, and/or posterior surfaces of the expanders. Results Total adhesion occurred in 18 cases, non-adhesion in 15 cases, and partial adhesion in 46 cases. Of the non-adhesion cases, 80% (n=12) were with Mentor CPX4 expanders, while 94.4% (n=17) of the total adhesion cases were with Natrelle expanders. Of the partial adhesion cases, 90.7% involved the anterior-cephalic surface. The type of tissue expander showed a statistically significant relationship with the number of attachments in both univariate and multivariate logistic regression analyses (P<0.001) and with total drainage only in the univariate analysis (P=0.015). Conclusions We sought to identify the location(s) of adhesion after tissue expander insertion. The texture of the implant was a significant predictor of the success of adhesion, and partial adhesion was common. The anterior-cephalic surface showed the highest adhesion rate. Nevertheless, partial adhesion suffices to prevent unwanted rotation of the expander.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.798-802
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• 2011

Purpose: A wart is caused by epidermal infection with the human papilloma virus. Although wart naturally disappears in some cases, it require treatment because of pain, aesthetic problem, and the possibility of malignant change. Conventional non-surgical treatment cannot be a fundamental solution for the pain and has such disadvantages as frequent recurrence and difficulties in achieving a satisfactory outcome. A surgical procedure was performed on patients with wart and the procedure had a good outcome. Methods: We investigated the gender, age, lesion site, mean treatment duration, and presence or absence of recurrence in 21 patients with a wart within the period of January 2007 to July 2011. For local lesions, primary closure, including subcuticular suture after the excision, was performed. If the defect size was too big to do primary closure, we performed rotation flap. For wide multiple lesions, a split thickness skin graft was performed. Results: Among the 21 patients, 12 patients were male and 9 patients were female, and their mean age was 42 years (SD=17.38, range: 11~75 years). The lesion site was the foot in 10 patients, the hand in 8 patients, the face in 2 patients, and the scalp in 1 patient. The mean treatment duration was 13.5 days (SD=4.36, range: 6~15 days) for the primary closure or rotation flap, and 18.5 days (SD=2.12, range: 17~20 days) for the skin graft. 20 patients were cured without recurrence. No recurrence was observed in the patients who underwent primary closure or rotation flap. One of the two patients who underwent a skin graft of their wart that had covered their entire palm had local recurrence in part of her finger tips. Conclusion: We performed surgical procedure on recalcitrant wart. As a results, we can treat it with short treatment duration, low recurrence rate and less scarring and get high patient satisfaction.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.237-241
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• 1986

In clinical microsurgery, limitation of space often prohibits rotation of a double clamp in an end-to-end anastomosis, or shortage of length of the secondary vessel in an end-to-side anastomosis does not allow visualization of the back wall. In these situation, back wall repair is extremely difficult. To overcome this problem, we use continuous suture technique without rotation of double clamp for end-to-end and end-to-side anastomosis of the 40 rat femoral arteries. After continuous sutures for microarterial anastomosis, the following results were obtained: Continuous sutures are useful in anastomosis where there is unavoidable limited access to the posterior wall and for some of the larger vessels now being anastomosed in free flap and other reconstructive surgery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.821-825
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• 2007

In this study, the single hardening model with stress history-dependent plastic potential, which has been most recently proposed based on the critical state soil mechanics and needs few model parameters, was verified for the normally, lightly, and heavily over-consolidated clayey specimens. The triaxial compression tests were strictly conducted. The predictions using the single hardening model generally agree with the measurement. The discrepancy exists on its main focusing on the principal stress rotation; however, the plastic work H and the principal stress rotation angle ${\beta}$ are found to be effective indicators of loading history for the plastic potential function of the stress path dependent materials.