금속판 고정술을 이용한 하부경추부 전방접근법의 임상적 고찰

허성철,임준섭,윤경식,조한호,오민석 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.10

The surgical approach to the lower cervical lesions, especially in traumatic injuries, has been controversial. Some authors advocated posterior fusion for such lesions, while others disagreed and reported good operative results with anterior approach using several types of cervical plates. We analysed 28 patients with lower cervical spine traumatic as well as pathological lesions who underwent 32 anterior surgical interventions with cervical plates during the period of August, 1991 and December, 1993. A successful postoperative vertebral stability was obtained in 25 patients(89.3%) and in 19 patients(87.5%) who had predominent posterior ligamentous injuries. Serious complications such as esophageal perforation and postoperative angulation were seen in 5 patients(17.3%) that were related to the process of reduction. With our clinical experiences, we support anterior fusion with cervical plates particularly for lower cervical lesions even though posterior fusion has been preferred for traumatic posterior ligamentous complex injuries.

비대칭 성장판 성장 억제를 이용한 사지 각 변형의 교정

장우영(Woo Young Jang),최윤성(Yun Seong Choi),유원준(Won Joon Yoo) 대한정형외과학회 2016 대한정형외과학회지 Vol.51 No.2

성장이 남아있는 소아 청소년에서 사지의 각 변형은 정형외과 영역에서 드물지 않게 만나는 문제이다. 각 변형을 교정하는 수술적 방법 중, 비대칭 성장판 성장 억제술 또는 성장 조절법은 성장 중인 골에 지속적인 외력을 가하여 소성 변형을 유도하는 방법이다. 비대칭 성장판 성장 억제술의 원리를 이용한 수술법에 사용되는 내고정물로는 스테이플, 성장판 통과 나사못 및 8자 금속판으로 대표되는 긴장대 금속판이 있다. 스테이플을 이용한 일시적 반골단판 유합술은 각 변형 교정에 있어 약 60%-80%의 성공률을 보이는 것으로 알려져 있다. 성장판을 통과하는 나사못을 이용한 골단판 유합술은 스테이플이나 8자 금속판에 비해 더 우월한 점은 피부 절개가 더 작고, 수술 시간도 더 짧으며, 수술 후 고정이 필요 없이 빨리 일상 생활에 복귀할 수 있다는 점이다. 8자 금속판은 스테이플이나 성장판을 통과하는 나사못에 비해 각 교정의 moment arm이 길어서 각 변형 교정에 더 유리하고 주변 정상 성장판의 성장을 덜 억제하는 이점이 있다. 비대칭 성장판 성장 억제술은 소아 청소년의 사지 각 변형을 교정하는 데 있어서 간편하면서도 강력한 효과를 가진 수술법이다. 세 가지 종류의 내고정물들은 서로 장단점이 있고 아직까지 교정력이나 합병증에 있어 확실한 우열을 가리기 힘들기 때문에 환자 개개인의 특성을 잘 평가하여 가장 적절하다고 생각되는 내고정물을 선택하여야 한다. Angular deformity of extremities in children and adolescents with residual growth is not a rare condition in orthopaedics. Asymmetrical physeal suppression or guided growth method, one of the surgical techniques for correction of angular deformity, is a method of inducing plastic deformation by application of constant external force to a growing bone. Internal fixation devices used for asymmetrical physeal suppression include staples, transphyseal screws, and tension band plates, most representatively the 8-plate. Temporary hemiepiphysiodesis using staples is reported to show a success rate of 60% to 80%. Epiphysiodesis using transphyseal screws has several advantages over staples or 8-plates; smaller skin incision, shorter operation time, no postoperative splint or cast, faster return to daily life. Advantages of 8-plates over staples or transphyseal plates include a longer moment arm, which enables better correction of angular deformity and less suppression of the growth of the nearby normal growth plate. Asymmetrical physeal suppression is a simple and effective surgical method in correcting angular deformity of extremities of children and adolescents. Each of three internal fixation devices discussed in the current article has strengths and weaknesses and superiority in terms of angular correction power and complication rate, however further study is needed. Therefore, the most appropriate device should be selected according to the condition of each patient.

국립중앙박물관 소장 유리건판과 기록자료로 본 황해도 성불사(成佛寺)의 불교조각

허형욱 ( Heo Hyeonguk ) 국립중앙박물관 2024 박물관과 연구 Vol.1 No.0

Gelatin dry plate photographs dating to the Japanese colonial era and the official documents from the Japanese Government-General of Korea Museum in the collection of the National Museum of Korea are significant materials documenting cultural heritage in North Korea before it was severely damaged in 1950 during the Korean War. There has been an increase in recent years in studies of Buddhist sculptures in North Korea based on these photographs and documents. This paper presents some new comments on the Buddhist sculptures at Seongbulsa Temple in Hwangju, one of the most famous temples in Hwanghae-do Province, based on the related existing research outcomes. This paper aims to facilitate a more comprehensive understanding of the Buddhist sculptures at Seongbulsa Temple by chronicling its history based on historical records, examining its current status, and exploring in detail the production dates and backgrounds of the Buddhist sculptures featured on gelatin dry plates. Prior to Korea’s liberation from Japan in 1945, Seongbulsa housed at least seven sculptural items: two Bodhisattva statues, four Buddha statues, and a triad. Two items are from the early Goryeo period, one is from the late Goryeo period, three are from the early Joseon period, and one is from the late Joseon period. Among them, two surviving items are noteworthy. One is the early Goryeo-era Stone Seated Bhaishajyaguru Buddha photographed in Eungjinjeon Hall at Seongbulsa Temple. A close examination of a schematic drawing of the sculpture’s pedestal made at the time it was photographed reveals that its material accords with the materials used for the headless Stone Seated Bhaishajyaguru Buddha and pedestal currently found in the old Sangwonam Hermitage site in the Inner Geumgang Valley of Jeongbangsan Mountain. This accordance could mean that the statue is a new significant example of early Goryeo Buddhist sculpture in North Korea. The other notable sculpture is the Gilt-bronze Seated Amitabha Buddha Triad created in 1454 (the second year of the reign of King Danjong) and discovered in Geungnakjeon Hall at Seongbulsa. This statue is currently in the collection of the Sariwon History Museum in Hwanghae-do Province. It is an important example of a dated small gilt-bronze Buddhist statue from the early Joseon period found in North Korea. This paper is a case study of Buddhist sculptures in North Korea, focusing on Seongbulsa Temple. Further utilization of the National Museum of Korea’s gelatin dry plates will contribute to developing the study of the history of Korean Buddhist sculpture.

하부지지구조물 바닥판 구멍크기 변경이 원자로 노심 입구 유량분포에 미치는 영향에 관한 수치해석

이공희(Gong Hee Lee),방영석(Young Seok Bang),정애주(Ae Ju Cheong) 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.11

본 연구에서는 하부지지구조물 바닥판의 외곽영역에 위치한 구멍의 크기 변경(구멍 직경 감소)이 노심 입구 유량분포에 미치는 영향을 조사하기 위해 상용 전산유체역학 소프트웨어인 ANSYS CFX R.15를 사용하여 계산을 수행하였고, 기존 바닥판 구멍 형태에 대한 계산 결과와 비교하였다. 결론적으로 하부지지구조물 바닥판의 외곽영역에 위치한 구멍의 직경 감소를 통해 노심 입구에서 보다 균일한 유량 분포를 얻을 수 있었다. 따라서 원자력 규제측면에서 볼 때 본 연구에서 제시한 하부지지구조물 바닥판의 외곽영역 구멍 형태의 설계 변경은 연료집합체의 기계적 건전성 및 노심 열적여유도를 향상시킬 수 있다는 측면에서 바람직할 것으로 판단된다. In this study, to examine the effect of a hole size change(smaller hole diameter) in the outer region of the lower-support-structure-bottom plate(LSSBP) on the reactor core-inlet flow-distribution, simulations were conducted with the commercial CFD software, ANSYS CFX R.15. The predicted results were compared with those of the original LSSBP. Through these comparisons, it was concluded that a more uniform distribution of the mass flow rate at the core-inlet plane could be obtained by reducing the hole size in the outer region of the LSSBP. Therefore, from the nuclear regulatory perspective, design change of the hole pattern in the outer region of the LSSBP may be desirable in terms of improving both the mechanical integrity of the fuel assembly and the core thermal margin.

고압가스 압력용기의 강도안전성에 관한 수치해석적 연구

김청균(Chung Kyun Kim),김승철(Seung Chul Kim) 한국가스학회 2010 한국가스학회지 Vol.14 No.2

고압가스 압력용기의 강도안전성을 FEM으로 해석하였다. 본 연구에서 고려한 강재용기의 내압은 서비스 충전압력 9kg/cm², 가스충전 최고압력 18.6kg/cm², 안전변 작동 최고압력 24.5kg/cm², 수압시험압력 34.5kg/cm²이다. FEM 해석결과에 의하면, 서비스 충전압력 9kg/cm²와 충전최고압력 18.6kg/cm²에 대한 강도안전성은 가스용기에 걸리는 응력이 강재의 항복강도 이내에 있기 때문에 안전한 것으로 나타났다. 그러나 수압시험압력 34.5kg/cm²을 가하였을 때에 발생하는 응력은 항복강도를 충분히 넘어서기 때문에 불안전하지만, 인장강도 이내에 존재하기 때문에 아직은 안전하다. 수압시험압력을 용기에 자주 공급하면 용기는 소성변형에 의한 피로잔류응력이 특히 하단반구부에 축적되므로 파손될 수 있다. 계산결과에 의하면, 스커트 지역에 작용하는 집중하중은 하단반구부에 영향을 미치지 않지만, 용기에서 가장 취약한 부분은 용기의 몸체와 스커트 사이에 위치한 하단반구부의 중간부분임을 알 수 있다. 따라서 하단반구부의 형상은 고압가스 저장용기 설계에서 중요한 요소라는 것을 보여주는 FEM 해석결과를 제공하고 있다. The strength safety of high pressure gas cylinder has been analyzed by using a finite element method. In this study, the internal gas pressures of a steel bombe include a service charging pressure of 9kg/cm², high limit charging pressure of 18.6kg/cm², high limit of safety valve operation pressure 24.5kg/cm², and hydraulic testing pressure of 34.5kg/cm². The computed FEM results indicate that the strength safety for a service charging pressure of 9kg/cm² and high limit charging pressure of 18.6kg/cm² is safe because the stress of a gas cylinder is within yield strength of steel. But the stress for a hydraulic testing pressure of 34.5kg/cm² sufficiently exceeds the yield strength and remains under the tensile strength. If the hydraulic testing pressures frequently apply to the gas cylinder, the bombe may be fractured because a fatigue residual stress is accumulated on the lower round end plate due to a plastic deformation. The computed results show that the concentrated force in which is applied on a skirt zone does not affect to the lower round end plate, and the most weak zone of a bombe is a middle part of a lower round end plate between a bombe body and a skirt for a gas pressure. Thus, the FEM results show that the profile of a lower round end plate is an important design parameter of a high pressure gas cylinder.

LPG 강재용기의 응력강도 안전성에 미치는 코너반경의 영향

김청균(Chung Kyun Kim) 한국가스학회 2015 한국가스학회지 Vol.19 No.1

본 연구는 LPG 강재용기에서 상단반구와 하단반구의 코너반경이 응력강도 안전성에 미치는 영향을 FEM으로 해석한 것이다. FEM 해석결과에 의하면, 응력강도 안전성에 큰 영향을 미치는 요소는 용기의 두께보다 상단반구 및 하단반구의 코너반경이다. 그러나 강재용기의 두께는 경량화에 직결되기 때문에 간과해서는 안 되는 중요한 설계요소이다. LPG 강재용기의 강도안전성 검사에서 최고시험압력이 3.04MPa임을 감안할 때, 20kg용 LPG 강재용기의 두께는 2.3~2.6mm, 상단반구와 하단반구의 코너반경은 157mm 이상으로 최적화 설계하는 것이 바람직함을 알 수 있다. This paper presents the stress strength safety of LPG steel cylinder for various corner radiuses of upper round end plate and lower round end plate by using a finite element method. The FEM analyzed results indicate that the most influential elements is a corner radius of upper round end plate and lower round end plate rather than a thickness of LPG cylinder. But, the thickness of a steel cylinder is an important design element considering for a weight reduction of a cylinder. Thus, this paper recommends that the LPG steel cylinder thickness is 2.3~2.6mm and the corner radius of upper round end plate and lower round end plate is over 157mm as an optimum design for the maximum testing pressure of 3.04MPa.

PRACTICAL EVALUATION OF BALL STUD PLATING EFFECTS ON THE INCREASE OF FREE GAP OF BALL JOINTS IN THE VEHICLE

정수식,이영제,박상오 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.5

The abnormal noises, such as clunking and popping, are usually generated when the car turns or drives over bumps. It could happen frequently when the free gap (clearance) values in the axial direction of the lower control arm ball joint are higher than normal values. The spherical surface of the ball stud is commonly assumed to have been corroded by foreign substances such as water, and the rough surface of the corroded ball stud accelerates the abrasion of the bearing contact portion to increase the free gap. Thus, the dust cap material and shape have been improved over time. However, there are still recurrences. The objective of this study was to evaluate two ball studs with different plating thicknesses and one uncoated sample from the reproducibility test simulating vehicle behavior conditions under environment test conditions. The findings of this study were as follows: First, the ball stud plating is advantageous in corrosion resistance, however, the thickness of the plating is uneven and the surface becomes rough with time, thereby accelerating the abrasion of the bearing contact portion. Second, as the surface of the ball stud wears, oscillating torque decreases and the axial free gap increases, which is more disadvantageous as the thickness of the ball stud sphere becomes thicker. Therefore, uncoated ball joint was defined as the best option.

판과 쉘의 선형탄성해석에서 저차고체요소의 성능 비교연구

이영정,이상진 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

The purpose of this study is to investigate the performance of lower order solid finite elements in the elastic analysis of plate and shell structures. The 8-node solid finite elements are formulated with three different ways such as the use of standard strain-displacement relationship, B-bar method and enhanced assumed strain method. The convergence of solid elements is investigated by using comprehensive three obstacle shell finite element analysis benchmark tests. From numerical results, the solid finite element with enhanced assumed strain method exhibit a better performance than other two solid finite elements. Finally, we propose the present numerical results as a benchmark test suite for future solid finite element development.

하부 실리콘 플레이트의 두께에 따른 FCP 표면 오차에 관한 연구

김지혜 ( Kim Ji-hye ),정경태 ( Jeong Kyeong-tae ),이동훈 ( Lee Donghoon ) 한국건축시공학회 2023 한국건축시공학회 학술발표대회 논문집 Vol.23 No.1

Recently, with the digitalization of the construction industry, free-form building construction technology is developing. However, the technology for manufacturing free-form concrete panels is still insufficient. In this study, the surface error of the FCP according to the thickness of the lower silicon plate, which is a component of the existing lower multi-point press, was analyzed in order to manufacture a precise FCP. As a result of the analysis, it was found that the thinner the thickness, the larger the error value. These results can be used as a basis for existing research and are expected to be used for research on high-quality FCP manufacturing technology.

실증실험을 통한 태양열원 하이브리드 제습냉방시스템의 성능 확인

염형열(Hyung-Yul Yum),김종현(Jong-Hyun Kim),홍희기(Hiki Hong) 대한설비공학회 2015 대한설비공학회 학술발표대회논문집 Vol.2015 No.11