• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.45-49
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• 2004

Chondroblastoma is a benign chondroid-forming tumor usually originating in the epiphysis. The base of metatarsal bone contains neither an epiphysis nor a secondary ossification center and so is the rare site of chondroblastoma. Here, we present a case of chondroblastoma of the base of fifth metatarsal bone in 34-year-old man. Histologically, the osteoclast-like giant cells were abundant enough to simulate a giant cell tumor. And the chondroid intercellular matrix was intermixed but scanty. However, the background mononuclear cells showed irregular and indented nuclei with longitudinal clefts and positive immunoreactivity for S-100 protein, as the evidence of chondroblasts.

• Journal of Conservation Science
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• v.19
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• pp.85-98
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• 2006

Rock property of the Seosan Maaesamjonbulsang is composed of biotite granite with medium grained texture. The triad Buddha is highly deteriorated by the joint, fracture, break-out, exfoliation, dew condensation of the surface and discoloration of the secondary pollutant. Host rock of the triad Buddha is divided dozens of rock blocks with various shape, and developed irregular discontinuity planes. Besides, the host rock is promoted biological pollution due to the surrounding crowded vegetation and high humidity environment. As the results of structural stability, it is confirmed that developed discontinuity system in the host rock is exposed instability sloping environment. Therefore, the host rock and surroundings are required maintenance, and required preservation by continuance monitoring for understand behavior of discontinuity system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.101-108
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• 2013

In this paper, we propose a method in which the negative acknowledge (NACK) message is used as command for cooperation and spectrum sharing. This allows for an automatic request for cooperation and sharing when the direct link of the primary user is in outage, and also allows for saving the number of control messages in cooperation-spectrum sharing based paradigm. In the sharing phase, the selected relay shares a power fraction of $1-{\alpha}$ for secondary transmitted signal while the remaining of ${\alpha}$ is for primary retransmitted signal. In the case of no relay collected, primary transmitter uses NACK as a command to retransmit the signal with fully power fraction (${\alpha}=1$). Both systems are assumed to employ BPSK signals. In this scheme, we propose the joint optimal decoding in the secondary user. The frame error rate (FER) performance at both systems is then analyzed. The theoretical and simulation results validate the analysis and confirm the efficiency of the protocol.

• Clinics in Shoulder and Elbow
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• v.11 no.1
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• pp.19-23
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• 2008

Purpose: To evaluate the bursoscopic findings of refractory primary adhesive capsulitis of the shoulder and to determine the clinical correlation. Materials and Methods: Arthroscopic capsular release was performed in 21 refractory adhesive capsulitis patients who had not responded to conservative treatment. The VAS for pain, range of motion, UCLA score was checked before and after surgery, and at the last follow up. Results: Bursitis, mild friction and impingement on coracoacromial ligament, as well as adhesion were observed. The function and pain improved earlier than after simple acromiohumeral joint capsular release. Conclusion: Subacromial bursoscopy helps rule out a hidden secondary frozen shoulder or secondary changes with primary adhesion. In addition, it has the advantage of being both a treatment and procedure for making a prognosis.

• Structural Engineering and Mechanics
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• v.61 no.4
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• pp.497-510
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• 2017

A framed structure may be composed of two sub-structures, which are linked by a hinged joint. One sub-structure is the primary system and the other is the secondary system. The primary system, which is subjected to the periodic external load, can give rise to an auto-parametric resonance of the second system. Considering the geometric-stiffness effect produced by the axially internal force, the element equation of motion is derived by the extended Hamilton's principle. The element equations are then assembled into the global non-homogeneous Mathieu-Hill equations. The Newmark's method is introduced to solve the time-history responses of the non-homogeneous Mathieu-Hill equations. The energy-growth exponent/coefficient (EGE/EGC) and a finite-time Lyapunov exponent (FLE) are proposed for determining the auto-parametric instability boundaries of the structural system. The auto-parametric instabilities are numerically analyzed for the two frames. The influence of relative stiffness between the primary and secondary systems on the auto-parametric instability boundaries is investigated. A phenomenon of the "auto-parametric internal resonance" (the auto-parametric resonance of the second system induced by a normal resonance of the primary system) is predicted through the two numerical examples. The risk of auto-parametric internal resonance is emphasized. An auto-parametric resonance experiment of a ${\Gamma}$-shaped frame is conducted for verifying the theoretical predictions and present calculation method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.81-87
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• 2017

This paper describes the dynamic behavior and enhancement of Korean high-speed trains. The tail vibration reduction method of the yaw damper installation method change, which was derived from previous research, was applied to the running test of high-speed train. In addition, the vibration reduction method for the entire vehicle was derived by a numerical method and its effect was confirmed by a running test. The improved design was applied to the double-deck high-speed train coaches and the commissioning proceeded without problems in dynamic behavior. Sensitivity analysis of the suspension parameters affecting the critical speed of Korean next-generation high-speed trains was performed and four design variables that greatly affected the critical speed were derived. These were in the order of the primary elastic joint x-directional stiffness, the secondary yaw damper series stiffness, the secondary lateral damper damping coefficient, and the carbody damper damping coefficient. By optimizing the design variables, the suspension parameter that improves the critical speed by 23.3% can be used in the commercial designs of Korean next-generation high-speed trains.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.127-135
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• 2003

The motions used in throwing place tremendous stresses on the soft tissues about the player's shoulder. In order to throw successfully, the shoulder complex must be capable of excessive motion, while maintaining stability of the glenohumeral joint. Injuries to the throwing player can result from acute trauma, but more commonly can be a result of overuse injuries from the repetitive throwing activity. Inbalance in the muscles and soft tissue about the shoulder can result in an injury secondary to abnormal biomechanics of the glenohumeral complex. The preventive measure a throwing player can take in order to maintain a healthy throwing shoulder is to participate in a regular shoulder strengthening program. It is when the muscles about the shoulder become imbalanced, secondary to either injury or relative weakness, that instability and injury can occur. By understanding the pitching motion and the relative contribution of the muscles, the treating physician has a framework on which to build knowledge regarding physical findings and diagnosis of shoulder injuries in throwing players. Once a diagnosis is made. a successful treatment plan may be developed for the player, including both conservative and , at time surgical means.

• The Journal of Korean Physical Therapy
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• v.22 no.2
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• pp.25-30
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• 2010

Purpose: Behavior and movement are accomplished by voluntary contractions of skeletal muscles. There are three types of muscle contractions: concentric, isometric and eccentric. The aim of our study was to determine whether there is a difference in the cortical activation pattern between concentric contraction and eccentric contraction of the wrist extensor muscle. Methods: Four healthy right-handed volunteers without any previous history of physical or neurological illness were recruited. fMRI scanning was done during 4 repeated blocks of concentric and eccentric exercise of the wrist joint. Subjects exercised for 12 seconds and then rested for 12 seconds before beginning the second set of exercises. To determine the excitability of cortical neurons during exercise, voxel count and intensity index were analyzed. Results: For right hand movements, when concentric contractions of the right wrist were done, only the left primary motor area was activated. In contrast, during eccentric contraction, both the primary motor area and secondary motor area were activated. For left hand movements, both concentric and eccentric contractions induced only the supplementary motor cortex and the contralateral primary motor cortex. Conclusion: During eccentric contractions, both the primary motor area and secondary motor area are activated in ipsilateral and contralateral brain areas. Thus, eccentric contractions require more complex and difficult movements than concentric contractions do.

• Journal of Korean Dental Science
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• v.7 no.2
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• pp.94-98
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• 2014

Numerous oral and maxillofacial surgeons have found facial space infections after tooth extraction. Most of these infections can be managed easily, but some of them could be life-threatening. Among the facial infections, temporal space infections are rare. Most temporal space infections could be observed as secondary to maxillary third molar infections, maxillary sinusitis, and maxillary sinus fractures. Note, however, that there are insufficient studies on temporal space abscess due to mandibular second molars, especially with acupuncture. A 74-year-old female came to our hospital with severe trismus and facial swelling on the right temporal, buccal, posterior auricular, and cervical regions. The patient had undergone extraction of tooth #47 secondary to dental caries by a general dentist about a month ago. After the dental procedure, the patient had been treated with acupuncture therapy around the right temporomandibular joint area at the oriental medicine clinic. We performed emergency incision and drainage under general anesthesia and started antibiotic treatment with IV ampicillin/sulbactam 3 g every 24 hours and vancomycin 1 g every 24 hours for 5 days. The patient's symptoms subsided and ultimately disappeared. Temporal space abscess after mandibular molar extraction is quite rare. In this case, the spreading mechanism against gravity is considered to be acupuncture therapy.

• Archives of Reconstructive Microsurgery
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• v.14 no.2
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• pp.152-156
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• 2005

Purpose: We reconstructed the thumb with groin flap combined with secondary heterodigital neurovascular island flap and report our 6 cases. Materials and Methods: Between March 2003 and August 2004, 6 degloving thumbs or amputation of thumbs were reconstructed with groin flap combined with secondary heterodigital neurovascular island flap. There ware 4 men and 2 women, and mean age was 42.2 years. The following parameters were evaluated. Results: Recipient thumb was no limitation of apposition. but flexion contracture of interphalangeal joint was about 10 degree in two cases. Average grip power were 80% and average pinch power were 70% that of the normal thumb. The two point discrimination was average 10.5 mm and double sensibility in 2 cases. 2 patients have cold intolerance. Neuroma formation was not made. Cosmetic results as judged by patients were that 4 cases are good and 2 cases are fair. Conclusion: If massive skin defect after degloving thumb or amputation of thumb are present, we consider the numerous methods for reconstruction of thumb. This surgical procedure is good methods because of it's pliability, sensation, satisfactory functional results but major disadvantage are the staged operation and cosmetic effect of the absence of thumb nail.