• Archives of Craniofacial Surgery
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• v.19 no.2
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• pp.139-142
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• 2018

Foreign bodies impacted in the maxillofacial region are often a diagnostic challenge. They can be a source of chronic inflammatory reactions and infections leading to the formation of an orocutaneous fistula. Such orocutaneous fistulas cause significant morbidity in most patients, eventually requiring surgery. Recently, we encountered a very rare case of an orocutaneous fistula caused by multiple foreign bodies in the cheek. Precise removal of the foreign bodies was required, and a double-sided anterolateral thigh free flap was used to reconstruct the defect. Surgeons should be aware of the complications of multiple foreign bodies and should be able to diagnose these on careful clinical examination.

• Clinical and Experimental Pediatrics
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• v.56 no.4
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• pp.176-181
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• 2013

Purpose: Apical muscular ventricular septal defects (MVSDs), especially in small infants, can be difficult to manage using surgical and percutaneous closure. An intraoperative perventricular procedure is a good option for closing apical MVSDs in small children with or without associated cardiac anomalies. We evaluated the results of hybrid perventricular closure of apical MVSDs performed using an Amplatzer duct occluder (ADO). Methods: We retrospectively reviewed the medical records of 5 patients who underwent hybrid perventricular closure of MVSDs with ADOs, from March 2006 to May 2011. The median patient age at the time of the procedure was 12 months (range, 25 days to 25 months), and the median body weight was 9.1 kg (range, 4.3 to 15 kg). Two patients had multiple ventricular septal defects (VSDs; additional perimembranous VSD in 1 patient and multiple MVSDs in the other) and 3 patients had associated cardiac anomalies; complete transposition of the great arteries in 1 patient and an atrial septal defect in 2 patients. All the procedures were performed on beating hearts, exception in 1 case. The ADO selected for the aortic side was at least 1 to 2 mm larger than the largest VSD in the left ventricle side. Results: The procedure was successful in all patients and each device was well positioned. During the median follow-up of 2.4 years, a small residual VSD was noted in 2 patients who had multiple VSDs and no leakage was seen in the other 3 patients. Conclusion: Perventricular closure of MVSD with an ADO is a good option for patients with apical MVSD. However, careful manipulation is important, especially in the case of small infants.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1780-1781
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• 2011

There have been numerous studies on application of robots to in-pipe inspection system. In this thesis, a mobile robot that can move through elbows and vertical pipes having diameter 100mm is developed. Defect detection technology for locating wall-thinnings, corrosions and foreign materials is developed for high temperature and pressure pipings in thermal power plants, utilizing laser sensors installed on the robot. Actual defect detection performance is evaluated with application of the developed robot system to a mock-up pipings.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.135-138
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• 2013

Sternal malformation/vascular dysplasia association is a rare congenital dysmorphology, which has not yet been reported in Korea. Its typical clinical features include a sternal cleft covered with atrophic skin, a median abdominal raphe extending from the sternal defect to the umbilicus, and cutaneous craniofacial hemangiomata. We report a case of a full-term newborn who presented with no anomalies at birth, except for a skin defect over the sternum and a supraumbilical raphe. Multiple hemangiomas appeared subsequently on her chin and upper chest wall, and respiratory distress due to subglottic hemangioma developed during the first 2 months of life. Her symptoms were controlled with oral prednisolone administration. No respiratory distress have recurred during the 3-year follow-up period.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.12-17
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• 2005

Several methods to resurface the lost cartilage of the knee have been used, multiple drilling, microfracture, abrasion arthroplasty Resurfaced cartilages resulting from above techniques are mostly fibrocartilage. Autologous osteochondral graft transfer and autologous chondrocyte transfer are known to resurface the lost cartilage with mostly hyaline cartilage. This article reviews basic researches, indications, operative technique, and clinical results of autologous osteochondral graft transfer.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.147-153
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• 2008

Several methods to resurface the lost cartilage of the knee have been used; multiple drilling, microfracture, abrasion arthroplasty. Resurfaced cartilages resulting from above techniques are mostly fibrocartilage. Autologous osteochondral graft transfer and autologous chondrocyte transfer are known to resurface the lost cartilage with mostly hyaline cartilage. This article reviews basic researches, indications, operative technique, and clinical results of autologous osteochondral graft transfer.

• Journal of Korea Foundry Society
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• v.24 no.2
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• pp.63-70
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• 2004

Foundry techniquews for large steel casting depends on the skills of foundrymen considerably. Especially, the problem of reducing casring surface defects is difficult to clear numerically. Statistical analysis by using wuantification theory for hot tear and sand inclusion, and multiple regression analysis for dimensional defects have been shown to be examples of solving this difficulty. Many causes of surface defects can be evaluated by these analyses. These evaluations serve as the base data of defect reduction and contribute to the constant improvement of casting quality and quality enhancement activity. The system to perform quality enhancement activity was developed and it proved very useful for transfering foundry techniques and skills from the old to young generations.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.3
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• pp.242-247
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• 2009

The ability of time reversal techniques to focus ultrasonic beams on the source location is important in many aspects of ultrasonic nondestructive evaluation. In this paper, we investigate the time reversal beam focusing of ultrasonic array sensors on a defect in layered media. Numerical modeling is performed using the commercially available software which employs a time domain finite difference method. Two different time reversal approaches are considered - the through transmission and the pulse-echo. Linear array sensors composed of N elements of line sources are used for signal reception/excitation, time reversal, and reemission in time reversal processes associated with the scattering source of a side-drilled hole located in the second layer of two layer structure. The simulation results demonstrate the time reversal focusing even with multiple reflections from the interface of layered structure. We examine the focusing resolution that is related to the propagation distance, the size of array sensor and the wavelength.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.169-174
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• 2012

Reduction unit is one of the most important components for railway vehicle because torque of motor must be transmitted to wheels of vehicle by reduction unit. However, According to advanced studies, it has been often broke down due to the damage, fatigue and wear of gear. To solve this problem, defect diagnosis methods of gear have been mainly using the vibration diagnosis technology through vibration waveform and frequency analysis. However, We should know vibration characteristics of normal state reduction unit prior to defect diagnosis. So in this paper, We had analyzed vibration characteristics of reduction unit in order to utilize monitoring system development. Comparison of targets is the vibration characteristics of normal state reduction unit about Electric Multiple Unit(EMU) and the High-speed trains(KTX, KTX II).

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.3
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• pp.517-526
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• 1987

This paper proposes a new testable design for Zipper CMOS circuits. This design provides an additional feedback loop (called self oscillation loop) whichin the circuit, for testability. The circuit is tested only by observing the oscillation on the loop. The design can be applied to the multistage as well as the single stage, and can detect multiple faults which are undetectable by the conventional testing method. The application and evaluation of test patterns become easy and fault-free responses are not necessary. If the conventional testing method is applied to the sequential Zipper CMOS circuit with the LSSD design technique, it has the serious defect that the initial value may change due to intermediate test patterns and much time taken to apply the necessary test patterns. By using the proposed design, however, the sequential Zipper CMOS circuit with the LSSD design technique can be easily tested without such a defect. Also, the validity of the design is verified by performing the circuit level simulation.