• Journal of Chest Surgery
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• v.35 no.10
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• pp.730-735
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• 2002

Diaphragm is innervated by phrenic nerve and lower intercostal nerves. For patients with avulsion injury of brachial plexus, an in situ graft of phrenic nerve is frequently used to neurotize a branch of the brachial plexus. We studied short-term and mid-term changes of diaphragmatic level and movement in patients with dissection of phrenic nerve for neurotization. Material and Method : Thirteen patients with division of either-side phrenic nerve for neurotization of musculocutaneous nerve were included in this study. With endoscopic surgical procedure, the intrathoracic phrenic nerve was entirely dissected and divided just above the diaphragm. The dissected phrenic nerve was taken out through thoracic inlet and neck wound and then anastomosed to the musculocutaneous nerve through a subcutaneous tunnel. With chest films and fluoroscopy, levels and movements of diaphragm were measured before and after operation. Result : There was no specific technical difficulty or even minor postoperative complications following endoscopic division of phrenic nerve. After division of phrenic nerve, diaphragm was soon elevated about 1.7 intercostal spaces compared with the preoperative level, but it did not show paradoxical motion in fluoroscopy. More than 1.5 months later, diaphragm returned downward close to the preoperative level (average level difference was 0.9 intercostal spaces; p＝NS). Movement of diaphragm was not significantly decreased compared with the preoperative one. Conclusion : After division of phrenic nerve, the affected diaphragm did not show a significant decrease in movement, and the elevated diaphragm returned downward with time. However, the decreased lung volumes in the last spirometry suggest the decreased inspiratory force following partial paralysis of diaphragm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.7
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• pp.743-749
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• 2014

In this study, a noncircular drawing (NCD) sequence for manufacturing high-strength and high-ductility pearlitic steel wires was investigated. Multipass NCD was conducted up to the 12th pass at room temperature with two processing routes (defined as the NCDA and NCDB), and compared with the wire drawing (WD). During the torsion test, delamination fracture in the drawn wire was observed in the 10th pass of the WD whereas it was not observed until the 12th pass of the NCDB. From X-ray diffraction, the circular texture component that increases the likelihood of delamination fracture of the drawn wire was rarely observed in the NCDB. Thus, the improved ability of the multipass NCDB to manufacture high-strength pearlitic steel wires with high torsional ductility compared to the WD (by reducing the likelihood of delamination fracture) was demonstrated.

• Journal of Chest Surgery
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• v.42 no.5
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• pp.645-648
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• 2009

We performed hand-assisted laparoscopic surgery for a 67-year-old male with a 5.6 cm sized abdominal aortic aneurysm. To the best of our knowledge, this is the first report in Korea. After an initial hand dissection of the abdominal aorta under laparoscopy, we performed proximal anastomosis and distal abdominal. aorta suture ligation through a 6 cm abdominal incision. Distal anastomosis was done at the bilateral common femoral arteries. He resumed his oral intake 6 hours after the surgery and discharged at the $4^{th}$ postoperative day.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.9-13
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• 2000

Wood demand is increasing more and more, but world has been confronted with decreasing forest resources. Korea has to depend upon foreign wood and wood-based products for more than 95 percent of total domestic demand per year. In order to heighten self-sufficiency for wood supply and demand, we have to develop wood substitutes. Rice hull is the cheapest agricultural by-product we can get in Korea, more over the production of rice hull amounts to 1 million tons per year. This study was carried out to utilize rice hull and to decide the optimum condition of rice hull pretreatment for manufacture of rice hull board. Steam explosion method gave the best result, and the next boiling treatment of 1 hour, the last 1 hour treatment with 1% NaOH solution. Optimum conditions of explosion method were 20kgf/$cm^2-1$ minute and 25kgf/$cm^2-1$ minute. Rice hull board made with exploded rice hull met the KS standard(KS F 3104, 1997) and showed the same strength as a control, PB. And also the 1 hour boiling treatment was more effective than the 1 hour treatment with 1% NaOH solution.

• Journal of The Geomorphological Association of Korea
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• v.15 no.2
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• pp.1-9
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• 2008

This studied area is divided into the mountains and the valleys. The former is nearly consisted of the badland, the latter is consisted of alluvial plains in the valley, fluvial terrace at the side of the river, alluvial fans between mountains and river terrace. There are many tors, mushroom rocks, sugarloaves, weathering pits, castle coppies, columnar rocks, pinnacles, balanced rocks carved on tuff by means of erosion in the Chiricahua Nat'l Monument. Willcox Playa is alkalic crust where was lake in pleistocene epoch at the time wetter than present. Alkalic crust was made of Ca, Na, K etc. There are sand dunes around here where was lake side in the past. We found many kinds of fossils at the 2,000ft thick horizons of valley alluvium. Pediment and alluvium bordered at the base of Mt. Dragoon wavily. Exfoliation and spalling and sheeting resulted in boulders around here. Tucson is alluvial plain filled in thick 7,0000ft valley. Volcano, fault, erosion, alluvium were and are processing in this area.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.282-283
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• 2012

국제표준규격(ISO 12215-5) 및 국내 플레저보트 검사지침의 개정에 따라 길이 6미터 미만의 플레저보트의 낙하시험에 의한 강도시험기준을 적용 가능하게 되었다. 하지만 현재 낙하시험은 자유낙하 시 내력 및 외력에 의한 선체 내부의 찌그러짐, 크랙, 박리, 파손 등을 육안으로 검사하는 방법으로 시험결과의 정량적인 판단이 이루어지지 않고 있다. 따라서 본 연구에서는 레저선박의 낙하시험을 위한 시스템 및 운용프로그램을 개발하여 플레저보트의 구조안전성의 정량적 평가가 가능한 시스템을 개발하고 다단 롤포밍 기법을 적용한 5m급 알루미늄레저보트에 적용하여 시스템의 성능을 검증하였다.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.541-547
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• 2016

본 연구에서는 Slotted flap을 장착한 WIG선(Wing In Ground effect ship)에서 발생하는 진동을 최소화하기 위해 WIG선의 공력특성을 수치적으로 분석하고 그에 따라 플랩 형상에 대하여 최적화를 진행하였다. 주 익형에 대한 형상은 NACA 4412로 고정한 상태에서 플랩의 각도와 x, y좌표를 설계변수로 설정하였으며, 그에 따라 설정한 평균 $C_L$값을 유지하면서 진동의 진폭 크기가 작아지도록 제한 조건 및 목적 함수를 설정하였다. 최적화된 익형에서 플랩과 주 익형 사이에서 분출되는 유체는 코안다 효과의 영향을 받아 플랩 윗부분을 타고 흐른다. 이로 인해 진동에 결정적인 영향을 미치는 박리영역이 억제되었으며, 진동이 최소화 되었다. 결론적으로 플랩의 최적화를 통하여 기본 설계 익형에서 89%의 진동이 저감되는 것과 동시에 Lift/Drag 96.2로 기본 설계 익형에 비해 4.1배 향상되었다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.92-100
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• 2015

The aim of this study is to evaluate the fracture characteristics of ductile fiber reinforced cement based composites with 1.5 volume ratio of polyvinyl alcohol and steel fiber by high velocity impact of steel projectile. We used gunpowder impact facility to evaluate the fracture characteristics of ductile fiber reinforced cement based composites by collision of steel projectile, and the impact velocity was from about 150 to 1,000m/s. The results of evaluation on the fracture characteristics of ductile fiber reinforced cement based composites were penetration grade, which is the kinetic energy more than three times of no-fiber reinforced specimen (Plain). In addition, ductile fiber reinforced cement based composites did not occurred critical damage other than the debris. In the case of mass loss, Plain specimen was proportional to kinetic energy of steel projectile, while ductile fiber reinforced cement based composites was not significantly affected by kinetic energy of steel projectile. In particular, this tendency had a close relationship with the fracture characteristics of back side of specimens, and the scabbing inhibiting efficiency of PVA specimen was higher than S specimen. In the results of verifying relationship between front and back side calculated by local damage, scabbing occurred at the region close to the back side in the ductile fiber reinforced cement based composites unlike Plain specimen. Thus, in this study, we examined principal fracture behaviors of ductile fiber reinforced cement based composites under collision of steel projectile, and verified that impact resistance performance was improved as compared to Plain specimen.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.52-59
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• 2023

The effects of dielectric curing temperature and temperature/humidity treatment conditions on the interfacial adhesion energies between Ti diffusion barrier/polybenzoxazole (PBO) dielectric layers were systematically investigated for Cu redistribution layer applications of fan-out wafer level package. The initial interfacial adhesion energies were 16.63, 25.95, 16.58 J/m² for PBO curing temperatures at 175, 200, and 225 ℃, respectively. X-ray photoelectron spectroscopy analysis showed that there exists a good correlation between the interfacial adhesion energy and the C-O peak area fractions at PBO delaminated surfaces. And the interfacial adhesion energies of samples cured at 200 ℃ decreased to 3.99 J/m² after 500 h at 85 ℃/85 % relative humidity, possibly due to the weak boundary layer formation inside PBO near Ti/PBO interface.

• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.216-222
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• 2002

With deterioration of the nation's infrastructure comes the growing, need for effective means of rehabilitating structures. Possibly one for the most challenging tasks is to upgrade the overall capacity of concrete structure. Therefore, considerable efforts are still being made to develop new construction materials. Rehabilitation of damaged RC structures occasionally requires the removal and replacement of concrete in the tension zone of the structural members. Typical situation where the tension zone repair is necessary is when the concrete in the tension zone in beams or slabs has spalled off as a result of corrosion in the bottom reinforcing bars or due to extensive fire. The rehabilitation of such conditions normally involves the removal of the concrete beyond the reinforcement bars, cleaning or replacing the tensile bars and reinstatement of concrete to cover the steel bars the original shape and size. This study focused on the flexural behavior of reinforced concrete beams strengthened by steel strand and carbon fiber sheet in the tension zone. The properties of beams are 15$\times$25 cm rectangular and over a 200cm span. Test parameters in this experimental study were strengthening methods, jacking volume, the number of sheet. We investigated the flexural behavior of simply supported RC beams which are strengthened with the carbon fiber sheet, monotonic loads. Attention is concentrated upon overall bending capacity, deflection, ductility index, failure mode and crack development of repaired and rehabilitated beams.