• Steel and Composite Structures
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• 제22권3호
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• pp.537-565
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• 2016

Australian railway networks possess a large amount of aging timber components and need to replace them in excess of 280 thousands $m^3$ per year. The relatively high turnover of timber sleepers (crossties in a plain track), bearers (skeleton ties in a turnout), and transoms (bridge cross beams) is responsible for producing greenhouse gas emissions 6 times greater than an equivalent reinforced concrete counterparts. This paper presents an innovative solution for the replacement of aging timber transoms installed on existing railway bridges along with the incorporation of a continuous walkway platform, which is proven to provide environmental, safety and financial benefits. Recent developments for alternative composite materials to replace timber components in railway infrastructure construction and maintenance demonstrate some compatibility issues with track stiffness as well as structural and geometrical track systems. Structural concrete are generally used for new railway bridges where the comparatively thicker and heavier fixed slab track systems can be accommodated. This study firstly demonstrates a novel and resilient alterative by incorporating steel-concrete composite slab theory and combines the capabilities of being precast and modulated, in order to reduce the depth, weight and required installation time relative to conventional concrete direct-fixation track slab systems. Clear benefits of the new steel-concrete composites are the maintainability and constructability, especially for existing railway bridges (or brown fields). Critical considerations in the design and finite element modelling for performance benchmarking of composite structures and their failure modes are highlighted in this paper, altogether with risks, compatibilities and compliances.

• Journal of Korean Neurosurgical Society
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• 제57권4호
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• pp.229-234
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• 2015

Objective : Pedicle screw fixation for spine arthrodesis is a useful procedure for the treatment of spinal disorders. However, instrument failure often occurs, and pedicle screw loosening is the initial step of a range of complications. The authors recently used a modified transpedicular polymethylmethacrylate (PMMA) screw augmentation technique to overcome pedicle screw loosening. Here, they report on the laboratory testing of pedicle screws inserted using this modified technique. Methods : To evaluate pullout strengths three cadaveric spinal columns were used. Three pedicle screw insertion methods were utilized to compare pullout strength; the three methods used were; control (C), traditional transpedicular PMMA augmentation technique (T), and the modified transpedicular augmentation technique (M). After control screws had been pulled out, loosening with instrument was made. Screw augmentations were executed and screw pullout strength was rechecked. Results : Pedicle screws augmented using the modified technique for pedicle screw loosening had higher pullout strengths than the control ($1106.2{\pm}458.0N$ vs. $741.2{\pm}269.5N$; p=0.001). Traditional transpedicular augmentation achieved a mean pullout strength similar to that of the control group ($657.5{\pm}172.3N$ vs. $724.5{\pm}234.4N$; p=0.537). The modified technique had higher strength than the traditional PMMA augmentation technique ($1070.8{\pm}358.6N$ vs. $652.2{\pm}185.5N$; p=0.023). Conclusion : The modified PMMA transpedicular screw augmentation technique is a straightforward, effective surgical procedure for treating pedicle screw loosening, and exhibits greater pullout strength than traditional PMMA transpedicular augmentation. However, long-term clinical evaluation is required.

• 대한정형외과스포츠의학회지
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• 제1권1호
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• pp.75-78
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• 2002

슬근의좌골결절부착부 견열손상은스포츠인구의증가와군대훈련을받고있는 젊은 남자에게 간혹볼수있는손상이며 대부분은젊은성인 특히 운동선수에게주로발생한다. 이는 슬관절이신전된상태에서고관절이 과도히굴곡되면슬근에강력한 긴장을 일으켜야기된다. 조기에진단하여 견열된 근육을 좌골에 부착시키는 수술적 치료로 기능을 회복시키고 기형을 교정할수있으나진단과치료가지연되면기능적으로나임상적으로양호한결과를얻기어렵다. 좌골결절에서슬근견열골절의수술적치료후생길수있는합병증은이소성골형성과고정실패외에크게알려진것이없으며, 특히좌골신경손상은보고된적이없다. 저자들은수상후3개월된슬근의좌골결절부착부파열을수술적치료한후좌골신경손상을경험하여보고하는바이다.

• Hip & pelvis
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• 제30권4호
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• pp.269-275
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• 2018

Purpose: The purpose of this study is to describe a method of inserting cement in the femoral head before fixation with dynamic hip screw to prevent screw cut out due to osteoporosis and to evaluate its clinical outcome in these patients. Materials and Methods: In this prospective study, 30 patients aged 60 years and older with intertrochanteric fracture were included. Bone mineral density was measured. After reaming of the femoral head and neck with a triple reamer and polymethyl methacrylate, bone cement was introduced into the femoral head using a customized nozzle and a barrel fitted on a cement gun. A Richard screw was inserted and the plate was fixed over the femoral shaft. Patients were mobilized and clinical outcomes were rated using the Salvati and Wilson's scoring system. Results: More patients included in this study were between 66 and 70 years old than any other age group. The most common fracture according to the Orthopaedic Trauma Association classification was type 31A2.2 (46.7%). The T-score was found to be $-2.506{\pm}0.22$ (mean${\pm}$standard deviation); all patients were within the range of -2.0 to -2.8. The duration of radiological union was $13.67{\pm}1.77$ weeks. Salvati and Wilson's scoring at 12 months of follow up was $30.96{\pm}4.97$. The majority of patients were able to perform their normal routine activities; none experienced implant failure or screw cut out. Conclusion: Bone cement augmentation may effectively prevent osteoporosis-related hardware complications like screw cut out in elderly patients experiencing intertrochanteric fractures.

• 대한정형외과학회지
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• 제55권3호
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• pp.193-199
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• 2020

골수강 내 금속정(골수정)은 1988년부터 대퇴골 전자간 골절을 치료하는 데 사용되어 왔다. 골수정은 활강고나사와 같은 골수강 외 고정 장치에 비하여 기계적 이점이 있으나 대퇴 전자간 골절 Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 31-A1 및 31-A2 골절 치료에 활강고나사보다 유리한 고정 기구인지에 대해서는 논란이 계속되고 있다. 지난 30년 동안 여러 시행 착오가 극복되었고 새로운 유형의 대퇴 골수정이 개발되어 임상에서 사용되고 있다. 새로 개발된 골수정은 삽입 과정이 쉬워지고 지연나사를 사용한 대퇴 골두의 고정 능력이 향상되어 왔다. 그러나 고정 실패율은 여전히 정형외과 의사의 수술 술기에 달려 있다고 할 수 있다. 이 종설에서 우리는 골수정을 이용하여 대퇴 전자간 골절을 치료하는 동안 내측 지지대 복원의 중요성에 대해 초점을 맞추고 그 기본 원칙에 대하여 논의해 보고자 한다.

• 대한족부족관절학회지
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• 제16권2호
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• pp.123-127
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• 2012

Purpose: The purpose of this study was to evaluate the clinical and radiographic results of the parallel-shaped modified Scarf osteotomy which is performed the Scarf osteotomy parallel to the shaft of the 1st metatarsal bone for hallux valgus deformities. Materials and Methods: We retrospectively reviewed 43 patients who had been treated by the parallel-shaped modified Scarf osteotomy for hallux valgus deformities between January 2006 and March 2011. We evaluated the results after this Scarf osteotomy with respect American Orthopaedic Foot & Ankle Society (AOFAS) scores, radiologic results by comparing intermetatarsal angle between 1stand 2nd metatarsal bones and hallux valgus angle. Results: We checked out the pre-operational and post-operational radiologic evaluation of intermetatarsal angle and hallux valgus angle between 1st and 2nd metatarsal bones. The mean AOFAS scores improved from 63.5 to 88.5. At final follow up, The hallux valgus angle improved from $31.4^{\circ}$ (16-52) to $9.0^{\circ}$ (3-13) and the intermetatarsal angle improved from $18.6^{\circ}$ (12-30) to $9.3^{\circ}$ (6-12) postoperatively. There was no case of major complications included recurrence of valgus deformity, correction or fixation failure and stress fractures. Conclusion: Our results suggest the our parallel-shaped modified Scarf osteotomy produces improved AOFAS scores, and effective correction of hallux valgus deformities. Our Scarf technique of osteotomy which is performed in parallel to the metatarsal bone minimizes the need for skill while more reliable and obtaining good correction and avoids associated complications.

• 무역학회지
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• 제44권1호
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• pp.301-319
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• 2019

This study is to review the Joseon government's attempt to recover the tariff autonomy lost in the course of entering into the unequal treaty with then-Japan government, as well as the practical effort to realize such an attempt. Among other attempts, the Joseon government ① began imposing tariffs starting September 1878 by establishing Dumopo Customs Office in Busan, ② dispatched on April 1881 a group of investigators to the competent authorities to review and look back the Joseon's tariff system against Japan and ③ entered into a tariff negotiation with then-Japan government on September 1881 with the emissary (Susinsa) Byeong-ho Jo representing the Joseon government. A series of these attempts, in line with each other, represents the Joseon government's ceaseless, constant effort to recover the tariff autonomy, which is what this study intends to review from the modern-day perspectives. Authored by Byeong-ho Jo to capture an advantageous position in the 1881's tariff negotiation against then-Japan government, 「Joilseui」 successfully represented the Joseon government's position on matters of ① the Japanese tax-autonomous district in Korea, ② defining tariff rates, ③ use of Japanese Yen for payment of tariffs, ④ effective period of the treaty and ⑤ export restrictions on grains. Failure of the Joseon government's attempt to recover the Tariff autonomy was attributable not only to, as 「Joilseui」 defined, ① governments' non-cooperative attitudes on the negotiation table, ② lack of authorities that the entrusted bodies had, ③ import tariffs defined high and ④ export restrictions on grains and red ginseng, but also to loss of the tariff autonomy in 1876 and the 1881's negotiation broken down that were plotted by then-Japan government's invasive policy.

• 대한두개안면성형외과학회지
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• 제24권1호
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• pp.37-40
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• 2023

Penetrating wounds to the face are cosmetically devastating and can be life-threatening. If the foreign body causing the penetrating wound is a piece of wood, small remnants might be left behind after the initial treatment. A 33-year-old male patient presented to the emergency center after a piece of lumber pierced his face as a passenger in a traffic accident. The patient's vital signs were stable, and emergency surgery was performed to remove the foreign body and repair the soft tissue. No noteworthy complications were seen after open reduction and internal fixation of the facial bone fractures. Seven months after the accident, the patient underwent scar revision along with full-thickness skin grafting for post-traumatic scars. After the surgery, pus-like discharge which was not previously present was observed, and the graft did not take well. A residual foreign body, which was the cause of graft failure, was found on computed tomography and the remaining foreign body was removed through revision surgery. The patient is receiving outpatient follow-up without any complications 6 months after surgery. This case demonstrates the importance of performing a careful evaluation to avoid missing a residual foreign body, especially if it is of wooden nature.

• 항공우주시스템공학회지
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• 제11권1호
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• pp.1-7
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• 2017

위성은 임무수행을 위하여 발사체에 탑재되어 목표하는 궤도상에 도달하게 된다. 발사체의 비행동안 위성은 사인, 랜덤, 충격과 같은 극심한 발사 진동환경에 노출되게 되며, 이에 따라 위성체 내부에 위치한 전장품 및 전장품 기판에는 각 진동요소에 의한 발사 하중이 작용하게 된다. 발사하중 작용시, 전장품 내부에 장착된 기판은 체결부를 경계로 수직방향의 굽힘 거동을 주로 일으키게 되며, 이로 인한 상대변위로 기판 위 소자의 납땜부 파괴와 도선의 단선, 기판 자체의 균열을 초래한다. 성공적인 임무 수행을 위해서, 위성의 전장품 설계는 상기 현상들에 대해 기판의 구조 건전성 및 피뢰파괴 신뢰도가 확보되어야한다. 본 논문에서는 기존에 구조해석이 기 수행되었던 다목적실용위성 3호에 탑재되는 고해상도 위성카메라용 X-band 안테나 구동장치인 APD(Antenna Pointing Driver) 전장품의 제어 보드를 대상으로 하여, 스테인버그의 식을 통해 진동 하중에 의한 허용 처짐과 최대 처짐을 도출해내고, 팔머그렌 마이너 방정식을 이용하여 수명관점에서 피로파괴 예측의 유효성을 입증하였다.

• Clinics in Shoulder and Elbow
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• 제11권2호
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• pp.77-81
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• 2008

회전근 개 파열에 대한 봉합 수술의 목적은 봉합 초기에 고정력을 높이고 건-골 사이의 간격 형성을 최소화 하며 반복적인 부하에 기계적인 안정성을 유지시키고 회전근 개의 끝이 뼈에 부착되어 치유될 때까지 건-골 사이의 치유 환경을 최적화시키는 것이다. 일열 봉합은 원래의 회전근 개 부착부에 건을 완전히 부착시키는 면적이 제일 적고 간격 형성에 취약하다. 이열 봉합은 고정 실패를 방지하는 힘이 일열 봉합보다는 우수하고 간격 형성도 더 적으며 교량형 봉합은 최대 인장력이 가장 크며 전단력 및 회전력에 강하고 간격 형성도 제일 적다. 이러한 것을 볼 때 이열 봉합 및 교량형 봉합이 일열 봉합보다 우수한 점이 많지만 수술 시간이 좀 더 오래 걸리고 삽입하는 나사못의 개수도 많아 수술료가 비싸다는 단점도 가지고 있다. 따라서 일열 봉합도 회전근 개의 점액 낭측 부분층 파열이나 작은 완전 파열에 쓰여질 수 있는 아직은 유용한 방법으로 사료된다.