• 한국임상수의학회지
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• 제38권2호
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• pp.94-97
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• 2021

An 18-year-old warmblood gelding was presented to Jeju National University Equine Hospital with chronic bilateral forelimb lameness. Navicular syndrome was suspected based on clinical findings, the hoof test, palmar digital nerve block, and radiographic results. Computed tomography (CT) was performed under general anesthesia. Bone cysts, enlarged vascular channels, sclerosis, and enthesophytes were identified in the navicular bone on CT images. Mineralization in the deep digital flexor tendon was also observed. CT can be a useful diagnostic tool for identifying lesions of the navicular bone and adjacent structures in horses. The horse was treated with an intra-bursal injection of triamcinolone and gentamicin. Lameness started to improve two days later and the horse was sound after two months of the injection. CT enabled us not only to diagnosis of navicular syndrome but also to determine the degree and extent of the lesions.

• Advances in Computational Design
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• 제6권1호
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• pp.1-13
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• 2021

Failure of a Multi-storeyed reinforced concrete framed structure occurs when a primary vertical structural component is isolated or made fragile, due to artificial or natural hazards. Load carried by vertical component (column) is transferred to neighbouring columns in the structure, if the neighbouring column is incompetent of holding the extra load, this leads to the progressive failure of neighbouring members and finally to the failure of partial or whole structure. The collapsing system frequently seeks alternative load path in order to stay alive. One of the imperative features of collapse is that the final damage is not relative to the initial damage. In this paper, the effect on the column and beam adjacent to statically removed vertical element in terms of axial force, shear force and bending moment is investigated. Using Alternate load path method, numerical modelling of two dimensional one bay, two bay with variation in storey heights are analysed with FE model in order to obtain better understanding of failure mechanism of multi-storeyed reinforced concrete framed structure. The results indicate that the corner column is more susceptible to progressive collapse when compared to middle column, using this simplified methodology one can easily predict how the structure can be made to stay alive in case of sudden failure of any horizontal or vertical structural element before designing.

• 한국지반공학회논문집
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• 제39권5호
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• pp.27-40
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• 2023

말뚝은 상부 구조물의 하중을 지지층으로 전달하는 구조체로 국내외 건설 현장에서 널리 사용되고 있다. 말뚝을 시공하는 방법은 지반조건, 시공위치, 주변현황, 환경적 요소, 공사비 등을 종합적으로 고려하여 결정하며 크게 직항타에 의한 타입방식과 선굴착 후 경타 또는 항타하는 방식으로 나눌 수 있다. 이 중 직항타는 말뚝 두부를 해머로 항타하여 원지반 내 소정의 심도까지 근입시키므로 항타 시 가해지는 에너지가 크고 이에 따른 항타진동 및 소음도 증가한다. 말뚝의 항타진동은 주변 시설물 및 지반에 영향을 미치므로 그 영향을 정량적으로 파악할 필요가 있다. 본 연구에서는 말뚝의 항타진동을 시간영역에서 산정하고, 직항타 시 말뚝과 인접하여 위치한 굴착면 및 가시설에 대하여 항타진동에 의한 영향을 유한차분해석법에 의한 2차원 동적수치해석을 통하여 분석하였다. 그 결과 파의 반사 및 재료감쇠가 적은 지표면에서 표면파에 의하여 지중보다 변위가 현저히 크게 발생하는 경향을 나타내었고 전체 변위 크기는 이격거리 증가에 따라 감소하나 수평방향 변위는 진동원과 먼 사면 상단부에서 연직방향 대비 더 큰 값을 보이며 법면부에 변위가 집중적으로 발생하는 특징을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권5호
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• pp.292-296
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• 2022

Objectives: During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications. Materials and Methods: One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively. Results: Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not. Conclusion: Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

• 전자공학회논문지D
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• 제36D권8호
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• pp.45-53
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• 1999

접지된 유전체층 위의 유한한 개수의 도체스트립에 의한 전자기 산란문제를 TM편파의 경우에 대하여 송수신 누설파 안테나와 격자결합기의 관점에서 고려하였다. 도체스트립에 유기된 전류를 미지수로 하는 적미분 방정식을 유도하고 모멘트법을 이용하여 풀었다. 도체스트립에 걸쳐서 특정한 전원(전류) 분포를 갖는 비균일한 누설파 구조를 구성하기 위하여 누설파 구조를 따라 인접하는 스트립들 사이의 거리의 스트립의 폭이 함께 변화되었다. 도체스트립의 전류분포 및 표면파 전력에 대한 해석결과들로부터 적절히 구성된 비균일한 누설파 구조의 수신 누설파 안테나 및 적자결합기 관점에서의 최대 결합효율이 균일한 구조에서의 80%에 비해 15%정도 개선된 95%가 됨을 관찰하였다.

• Computers and Concrete
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• 제27권3호
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• pp.283-295
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• 2021

Existing meso-scale models of concrete need to refine the mesh grids of aggregate and cement mortar, which may greatly reduce the computational efficiency. To overcome this problem, a novel meso-scale modeling strategy, which is based on rigid body spring method and Voronoi diagram, is proposed in this study to establish the meso-scale model of concrete. Firstly, establish numerical aggregate models according to user-defined programs. Circle aggregates are adopted due to their high efficiency in generation and packing process, and the grading of aggregate are determined according to the distribution curve proposed by Full and Thompson; Secondly, extract the centroids of aggregates, and then develop the Voronoi diagram in which aggregate centroids are defined as initial scatters; Finally, establish the rigid body spring model for concrete based on the Voronoi diagram. Aggregates are represented by rigid blocks, and assumed to be unbreakable. Cement mortar is concentrated into the interface between adjacent blocks and represented by two uniform springs. The number of grids is consistent with that of aggregates in specimens, and no mesh-refinement of aggregates and cement mortar is required. The accuracy and efficiency of the proposed modeling strategy are firstly identified by comparing the numerical results with the experimental ones, and then the applicability of the proposed strategy with different volume percentage occupied by aggregates is investigated.

• Steel and Composite Structures
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• 제50권3호
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• pp.265-280
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• 2024

The collapse behavior observed in single-story beam-column assembly (SSBCA) do not accurately represent the actual overall stress characteristic of multi-story frame structure (MSFS) under column loss scenario owing to ignoring the interaction action among different stories, leading to a disconnection between the anti-collapse behaviors of "components" and "overall structures", that is, the anti-collapse performance of frame structures with two different structural scales has not yet formed a combined force. This paper conducts a numerical and theoretical study to explore the difference of the collapse behaviors of the SSBCA and MSFS, and further to reveal the internal force relationships and boundary constraints at beam ends of models SSBCA and MSFS. Based on the previous experimental tests, the corresponding refined numerical simulation models were established and verified, and comparative analysis on the resistant-collapse performance was carried out, based on the validated modeling methods with considering the actual boundary constraints, and the results illustrates that the collapse behaviors of the SSBCA and MSFS is not a simple multiple relationship. Through numerical simulation and theoretical analysis, the development laws of internal force in each story beam under different boundary constraints was clarified, and the coupling relationship between the bending moment at the most unfavorable section and axial force in the composite beam of different stories of multi story frames with weld cover-plated flange connections was obtained. In addition, considering the effect of the yield performance of adjacent columns on the anti-collapse bearing capacities of the SSBCA and MSFS during the large deformation stages, the calculation formula for the equivalent axial stiffness at the beam ends of each story were provided.

• 한국음향학회지
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• 제27권8호
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• pp.435-442
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• 2008

n-gram 모델은 영어와 같이 어순이 문법적으로 제약을 받는 언어에 적합하다. 그러나 어순이 비교적 자유로운 한국어에는 적합하지 않다. 기존 연구는 어절 간 어순의 고려가 어려운 한국어의 특성을 반영한 twoply HMM을 제안했으나, 인접 어절 간 어순 구조를 반영하지 못하였다. 본 논문에서는 용언형태소 사이에 나타나는 인접 어절 간에 어순 특성을 반영하기 위해 두 어절을 결합하는 세그먼트 단위를 정의하고, 제안한 세그먼트 단위에서 문맥에 따라 확률을 달리 추정하는 two-path 언어모델을 제안한다. 그 결과 기존 한국어 언어모델에 비해 제안하는 two-path 언어모델은 기존 연구보다 25.68% 혼잡도를 줄였으며, 어절 간에 결합이 일어나는 경계인 용언형태소에서는 94.03%의 혼잡도를 줄였다.

• 한국임상수의학회지
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• 제28권1호
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• pp.163-172
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• 2011

Subcutaneous foreign body causes recurrent problems such as chronic soft tissue swelling and discharge. Wooden foreign body is one of the most common foreign bodies found in subcutaneous region including face, interdigit, and thoracic or abdominal area. This report demonstrated three dogs with wooden foreign body located in subcutaneous region of thoracic wall, abdominal wall and upper eyelid, respectively. Three dogs showed prominent soft tissue swelling adjacent the foreign body. A sinus or drainage tract was developed in two of these dogs. Ultrasonography revealed that hyperechoic linear structure accompanied acoustic shadow in all dogs, and which was diagnosed as a subcutaneous foreign body. Anechoic or hyperechoic fluid and hypoechoic tissue circumscribed the foreign body. A subcutaneous foreign body in case 3 was removed by clamp under ultrasound-guide with sedation. Sinography was performed in case 1 and clarified that the wooden foreign body did not perforate the thoracic wall and there was no direct communication into thoracic cavity. Ultrasonography and sinography can be used to identify the subcutaneous foreign body and evaluate the inflammatory reaction and relationship between foreign body and adjacent structures.

• 전자공학회논문지 IE
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• 제46권1호
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• pp.31-36
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• 2009

본 논문에서는 송 수신 차량이 편도 2차선의 일반국도를 80[km/h]의 속도로 주행하고, 곡선 반경은 교통사고율이 높은 통계자료를 근거하여 280[m], 직선도로의 길이는 정지시거를 고려하여 140[m], 곡선의 길이는 90[m], 곡선도로를 11.25[m] 간격으로 8개 지점을 선정하여 시뮬레이션 하였다. 그 결과 송 수신 차량간 거리가 111[m] 이상이 될 경우에는 좌, 우측 반사체에 의해 이루어지는 반사파의 전파경로 보다는 인접한 차량들에 의해 이루어지는 반사파의 전파 경로가 반복 반사수가 증가함으로 더 갈어지게 된다. 송 수신차량간 거리가 111[m] 미만인 경우에는 수신차량에 전파가 도달하기 위한 반복 반사는 $1{\sim}2$[회]정도 이었으며 송 수신 차량이 위치한 차선에 관계없이 인접한 차량에 의해 발생하는 반사파 보다는 좌, 우측 반사체를 경유하여 수신하게 되는 반사파의 전파경로가 $1{\sim}1.5[m]$정도 더 큼을 알 수 있었다.