• Smart Structures and Systems
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• 제19권4호
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• pp.393-402
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• 2017

Many vibration-based global damage detection methods attempt to extract modal parameters from vibration signals as the main structural features to detect damage. The local flexibility method is one promising method that requires only the first few fundamental modes to detect not only the location but also the extent of damage. Generally, the mode shapes in the lateral degree of freedom are extracted from lateral vibration signals and then used to detect damage for a beam structure. In this study, a new approach which employs the mode shapes in the rotary degree of freedom obtained from the macro-strain vibration signals to detect damage of a beam structure is proposed. In order to facilitate the application of mode shapes in the rotary degree of freedom for beam structures, the local flexibility method is modified and utilized. The proposed rotary approach is verified by numerical and experimental studies of simply supported beams. The results illustrate potential feasibility of the proposed new idea. Compared to the method that uses lateral measurements, the proposed rotary approach seems more robust to noise in the numerical cases considered. The sensor configuration could also be more flexible and customized for a beam structure. Primarily, the proposed approach seems more sensitive to damage when the damage is close to the supports of simply supported beams.

• Advances in nano research
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• 제8권3호
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• pp.229-244
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• 2020

In this paper, modified Kelvin's model has been used to analyze the orthotropic vibration frequencies of single walled carbon nanotubes with clamped-clamped and clamped-free boundary conditions. For this system the governing equation is developed with wave propagation approach. Armchair, zigzag and chiral structures are considered for the vibrational analysis to investigate the effect of different modes, in-plane rigidity and mass density per unit lateral area. Throughout the computations, on decreasing the length-to-diameter ratios, the frequencies of said structure increases. In addition, by increasing three different value of in-plane rigidity resulting frequencies also increase and frequencies decrease on increasing mass density per unit lateral area. The results generated using computer software MATLAB to furnish the evidence regarding applicability of present model and also verified by available published literature.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제36권1호
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• pp.30-36
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• 2014

There are many treatment options in management of mandibular condylar neck fractures. Closed reduction is the most conservative treatment; however, achievement of anatomic reduction is difficult, and there are some risks of mandibular functional impairment. Open anatomic reduction and internal fixation have some advantages; therefore, many oral and maxillofacial surgeons have attempted to achieve anatomic reduction through the open approach and extracorporeal reduction and fixation. However, when using this method, there is some risk of resorption of the fractured mandibular condylar head. Therefore, we designed a modified extracorporeal reduction technique, without detaching the lateral pterygoid muscle in order to maintain the blood supply to the fractured mandibular condylar head. We believe that this minor modification may minimize the risk of resorption of the fractured mandibular condylar head. In this article, we introduce this technique in detail, and report on two cases.

• Journal of Korean Neurosurgical Society
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• 제43권2호
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• pp.111-113
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• 2008

Recently, Harms and Melcher modified Goel's approach, the C1 lateral mass and C2 pedicle screw fixation, and the new technique is currently in favor among neurosurgeons. Comparing to the advantages of Harms construct, the disadvantages were not extensively investigated. We experienced a patient with severe occipital pain developed after the C1 lateral mass screw placement for the traumatic atlantoaxial instability. We reviewed literatures about Harms construct with focus on the occipital neuralgia as a postoperative complication and suggest here technical tips to avoid the troublesome pain.

• 대한족부족관절학회지
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• 제22권2호
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• pp.55-61
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• 2018

Chronic lateral ankle instability is a major complication of acute ankle sprains, which can cause discomfort in both daily and sports activity. In addition, it may result in degenerative changes to the ankle joint in the long term. An accurate diagnostic approach and successful treatment plan can be established based on a comprehensive understanding of the concept of functional and mechanical instability. The patients' history and correct physical examination would be the first and most important step. The hindfoot alignment, competence of the lateral ligaments, and proprioceptive function should be evaluated. Additional information can be gathered using standard and stress radiographs. In addition, concomitant pathologic conditions can be investigated by magnetic resonance imaging. Conservative rehabilitation composed of the range of motion, muscle strengthening, and proprioceptive exercise is the main treatment for functional instability and mechanical instability. Regarding the mechanical instability, surgical treatment can be considered for irresponsible patients after a sufficient period of rehabilitation. Anatomic repair (modified $Brostr{\ddot{o}}m$ operation) is regarded as the gold standard procedure. In cases with poor prognostic factors, an anatomical reconstruction or additional procedures can be chosen. For combined intra-articular pathologies, arthroscopic procedures should be conducted, and arthroscopic lateral ligament repair has recently been introduced. Regarding the postoperative management, early functional rehabilitation with short term immobilization is recommended.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.73-78
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• 2013

In this paper, the vibration for a pickup actuator is described by mathematically analyzing its suspension configuration and motion, confined to lateral and torsional directions of suspensions. In order to prove the accuracy of this result, it is compared to a finite element analysis. Also it is shown that modal frequencies can be modified by changing design parameters in mathematical motion expressions.

• 대한족부족관절학회지
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• 제18권4호
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• pp.147-152
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• 2014

Ankle arthrodesis has been used as standard treatment of ankle arthritis unresponsive to conservative treatment. Transfibular approach was used for ankles with severe deformities and minimally invasive arthroscopic ankle arthrodesis was used for patients with mild deformities. Anterior approach may be used when lateral approach couldn't be performed. Tibiotalocalcaneal arthrodesis is standard treatment for coexisting ankle and subtalar arthritis, and modified Blair arthrodesis can be used if the talus body resection is necessary in severe talar necrosis. In serious infection of ankle arthritis, arthrodesis can be performed as staged operation. In cases with low bone density and severe deformities, Charcot arthropathy should be considered.

• Earthquakes and Structures
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• 제10권4호
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• pp.913-938
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• 2016

'Stepped building' frames, with vertical geometric irregularity, are now increasingly encountered in modern urban constructions. This paper proposes a new approach to determine the lateral load pattern, considering the contributions from the higher modes, suitable for pushover analysis of stepped buildings. Also, a modification to the displacement coefficient method of ASCE/SEI 41-13 is proposed, based on nonlinear time history analysis of 78 stepped frames. When the newly proposed load pattern is combined with the modified displacement coefficient method, the target displacement for the stepped building frame is found to match consistently the displacement demand given by the time history analysis.

• Steel and Composite Structures
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• 제23권3호
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• pp.285-302
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• 2017

Buckling-restrained braced frames (BRBFs) are commonly used as the lateral force-resisting systems in building structures in the seismic regions. The nearly-symmetric hysteretic response and the delayed brace core fracture of buckling-restrained braces (BRBs) under the axial cyclic loading provide the adequate lateral force and deformation capacity to BRBFs under the earthquake excitation. However, the smaller axial stiffness of BRBs result in the undesirable higher residual drift response of BRBFs in the post-earthquake scenario. Two alternative approaches are investigated in this study to improve the elastic axial stiffness of BRBs, namely, (i) by shortening the yielding cores of BRBs; and (ii) by reducing the BRB assemblies and adding the elastic brace segments in series. In order to obtain the limiting yielding core lengths of BRBs, a modified approach based on Coffin-Manson relationship and the higher mode compression buckling criteria has been proposed in this study. Both non-linear static and dynamic analyses are carried out to analytically evaluate the seismic response of BRBFs fitted with short-core BRBs of two medium-rise building frames. Analysis results showed that the proposed brace systems are effective in reducing the inter-story and residual drift response of braced frames without any significant change in the story shear and the displacement ductility demands.

• Anatomy and Cell Biology
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• 제56권1호
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• pp.39-45
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• 2023

Fixation of radial head fracture with minimally invasive posterior approach remains a significant challenge. The aim of this study was to determine the feasibility of trans-anconeus posterior elbow approach and to observe lateral ulnar collateral ligament (LUCL) in extended elbows. This cadaveric study was performed in twenty upper limbs of fresh fixed adult male cadavers. An oblique incision was made in the middle segment of anconeus until the lateral ligament complex and the joint capsule had been revealed. A deep dissection was explored to observe the anatomical relationship of the LUCL to the anconeus. Measurements of the LUCL were recorded while the elbow was fully extended. The mean distance between the edge of the radial head and the proximal insertion of the LUCL was 13.3 mm (11.5-16.2 mm); the mean distance between the edge of the radial head and the distal insertion of the LUCL was 20.9 mm (19.2-23.4 mm); the distance between the edge of the radial head and the distal edge of the annular ligament was 11.2 mm (8.22-11.7 mm). By estimate correlation of the previous measurements, the direct and accessible way to expose the posterolateral articular capsule of the elbow joint was through a window in medial 2/3 of the middle segment of anconeus muscle. These trans-anconeus approach is useful. It provides good visualization, facilitates applying the implants, and lessens the risk of radial nerve injury. Awareness of the anatomy is mandatory to avoid injury of LUCL.