• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.213-218
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• 2012

Survey on the hypergolic igniter and rupture disc for liquid rocket engines was performed. The patent of the igniter for US MC-1 and Russia RD-170 Engine and the disc for NASA's space vehicle were analyzed. The types, characteristics, performances, design parameters and ASME standards of the disc are examined. The performances have manufacturing tolerance, reverse pressure, flow disturbance, fragmentation, material, working fluid and operating ratio. Also, survey on structural analyses of the rupture disc were performed.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.76-82
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• 2013

Survey on the hypergolic igniter and its rupture discs for liquid rocket engines was performed. The patents of the igniters for US MC-1 and Russia RD-170 engines and the discs for NASA's space vehicle were analyzed. The types of discs and holders, characteristics related to rupture pressures and working fluids, and ASME standards of the discs were examined. Also, survey on structural analyses of the disc were performed. Typical design features and experimental results of the currently developing igniter by the authors were presented.

• Journal of Chest Surgery
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• v.34 no.5
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• pp.414-417
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• 2001

흉부 대동맥의 비 외상성 자연 파열은 매우 드물지만, 발생시 응급수술이 요하는 위중한 질환이다. 본원에서는 전산화 단층 촬영과 경식도 초음파로 진단하고 부분 대동맥궁 치환술로 성공적으로 치료된 후 흉부 대동맥의 비 외상성 지연 파열 1례를 체험하였기에 문헌고찰과 더불어 보고하는 바이다.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.72-78
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• 2012

The rotator cuff is situated in a potential tight subacromial space and undergoes senescent structural changes commonly observed in other joints of the body. When the cuff fails, spontaneous healing of the torn tendon is not expected to occur, and multiple factors may be responsible. Its fibers are under tension and typically retract on tearing. The subacromial bursal inflammation and alterations in normal glenohumeral kinematics have been considered in the development of symptoms. Controversy continues to exist concerning the pathogenesis of rotator cuff disease. The heterogeneity of the disorder, as well as the notion that rotator cuff disease may not actually represent a continuum of the same process, but rather, is a compilation of independent disorders, may partly explain the differing viewpoints on its origin. Two contrasting pathogenetic mechanisms have been extensively described and include vascular, or intrinsic, causes and impingement, or extrinsic, factors. Other etiologies have also been reported that include trauma, congenital or developmental factors, and instability. For successful treatment of the rotator cuff diseases, it is essential to understand the structure and function of rotator cuff and to clarify the pathogenesis and natural history of its disorder.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.92-97
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• 2012

Purpose: The reparability of rotator cuff tears is very important to establish the indication of the surgical treatment of rotator cuff tears. We reviewed the factors that effect to reparability of rotator cuff tears, and considered about the surgical indication of rotator cuff tears. Materials and Methods: The reparability was considered by the surgical reparability and the postoperative healing potentials of rotator cuff. The natural history of rotator cuff tear gives us the information to make decision about the surgical treatment or the conservative treatment. Results: There are 3 general categories of factors that help predict the healing potential of a rotator cuff tear. These include surgical technique, biology, and environmental issues. Surgeon can control the surgical technique by himself. The control of biology comes from careful operative indications by age, acute trauma history, chronicity, and tear size. And the control of environmental factor can give better outcomes by cessation of smoking and nonsteroidal anti-inflammatory drug (NSAID). Conclusion: A better understanding of the natural history and the reparability of rotator cuff tear will help us to estabilish the indication of surgical treatement of rotoator cuff tears, and lead to satisfactory clinical outcomes.

• Archives of Hand and Microsurgery
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• v.24 no.1
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• pp.63-67
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• 2019

Spontaneous rupture of the extensor pollicis longus (EPL) tendon can occur in the 3rd extensor compartment after a distal radius fracture involving Lister's tubercle, steroid injections, or rheumatoid arthritis. We report a case of spontaneous rupture of the EPL tendon in a 26-year-old male patient who played a rhythm game, which requires repetitive wrist motions to play the drums. We also provide a comprehensive literature review along with the case report. From the authors' point of view, excessive and repetitive motion of the wrist, as shown in our case, can be a potential cause of spontaneous rupture of the EPL tendon.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.2
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• pp.93-97
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• 2004

Continued research needs to be devoted to understanding the natural history of rotator cuff tears. Recent studies have shown progression of tear, symptomatic flare-ups and irreversible change in rotator cuffs managed nonsurgically. These data allow the grouping of patients with rotator cuff tears into three categories based on risk-benefit ratios. Nonsurgical care should be maximized for patients with impingement symptoms only, with partial-thickness tears, with chronic tears, and for the elderly patients. The proper selection of candidates for nonsurgical management should lead to the high success rate quoted by multiple authors. Even though conservative treatment is necessary, early surgery should be considered for tears that are acute, small or medium, associated with shoulder loss of function, or occur in a younger patient. Prolonged nonsurgical care in these patients risks tear propagation and irreversible changes to the cuff, which may complicate rotator cuff repair.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.111-114
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• 2009

Aorto-iliac artery aneurysms are very rare and the natural course of this disease is not well known. However, the risk of rupture is high and the mortality rate after rupture is extremely high. Preserving the pelvic circulation is important for the treatment of aorto-iliac artery aneurysms. We report here on a case of a patient suffering with aorto-iliac artery aneurysms, and these were treated by a hybrid endovascular operation that combined an open bypass of both iliac vessels with endovascular repair.

• Composites Research
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• v.21 no.6
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• pp.23-30
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• 2008

In this paper, the effect of the natural aging on the strength distribution and structural service life of a Filament Wound (FW) composite pressure vessel was studied. The fiber failure strain, which is varied significantly, was considered as the design random variable and the strength analysis was carried out by probabilistic numerical approach. The progressive failure analysis technique and the First Order Reliability Method (FORM) were embedded in this numerical model. As the calculation results, the probability of failure was obtained for each aging time steps and it is found that the strength degradation in FW composite pressure vessel, due to the natural aging, appears within 10 year-aging-time. As an example of the life prediction under natural aging using arbitrary laminated model, the service lifetime of 13 years was predicted based on the probability of failure of 2.5% and the design pressure of 3,250 psi.

• Neonatal Medicine
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• v.15 no.1
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• pp.100-104
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• 2008

Ovarian cysts are the most common cystic abdominal masses in female newborns. It is believed to be derived from an overstimulation of the ovarian follicles by maternal, placental, and fetal hormones. Although most ovarian cysts resolve spontaneously, surgical management is mandatory for life-threatening, complicated cases, including torsion, intracystic hemorrhage, and rupture of the cyst. Rupture of ovarian cysts is thought to be exceedingly rare, but can lead to severe hemorrhagic ascites or peritonitis. We managed a case of a ruptured ovarian cyst in a female newborn who presented with mild abdominal distension and two episodes of gross hematuria. Exploratory laparotomy revealed a right ovarian cyst with torsion and rupture. She was successfully treated with a right salpingo- oophorectomy with no sequelae.