• Journal of Chest Surgery
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• 제22권6호
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• pp.1061-1069
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• 1989

A case of liposarcoma was reported in 52 year-old female. She had the operation history due to mediastinal lipoma at other Hospital before 26 months ago. Chest X-ray revealed a huge soft tissue mass- density at the entire right lung field, and left middle and lower lung field at admission. At the lateral film, the mass was located in the anterior and middle mediastinum. Transsternal bilateral thoracotomy was performed, followed by extirpation of liposarcoma, wedge resection of superior vena cava, angioplasty of superior vena cava, and then partial pericardiectomy. The post-operative treatment was 5500 rad irradiation. Post-operative course was uneventful, that was noticed by OPD follow-up for 10 months. Primary liposarcoma of the mediastinum is very rare tumor. This tumor grows to an enormous size, and symptoms are referable to compression of the contiguous intrathoracic structures. The treatment of choice is surgery in all cases. Such an approach serves to establish a tissue diagnosis, to relieve the patients* symptoms, and may results in a cure sometimes. Radiotherapy or/and chemotherapy seems to be ineffective, but should be further studied.

• Journal of information and communication convergence engineering
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• 제3권4호
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• pp.191-194
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• 2005

SU-8 is a epoxy based photoresist designed for MEMS applications, where a thick, chemically and thermally stable image are desired. However SU-8 has proven to be very sensitive to variation in processing variables and hence difficult to use in the fabrication of useful structures. In this paper, negative SU-8 photoresist processed has been characterized in terms of delamination, based on a full factorial designed experiment. Employing the design of experiment (DOE), a process parameter is established, and analyzing of full factorial design is generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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• pp.97-105
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• 1997

A methodology to identify a baseline modal model of a complicated 3-D structure using limited structural and modal information is experimentally examined. In the first part, a system's identification theory for the methodology to identify, baseline modal responses of the structure is outlined. Next, an algorithm is designed to build a generic finite element model of the baseline structure and to calibrate the model by using only a set of post-damage modal parameters. In the second part, the feasibility of the methodology is examined experimentally using a field-tested truss bridge far which only post-damaged modal responses were measured for a few vibration modes. For the complex 3-D bridge with many members, we analyzed to identify unknown stiffness parameters of the structure by using modal parameters of the initial two modes of vibration.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.417-420
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• 2006

For a better understanding of the fracture behavior of concrete structures, knowledge of the post-cracking behavior of concrete material is essential. The tension softening diagram can describe the post-cracking behavior of concrete in tension. In this paper, Four points bending tests with a notch have been carried out to investigate tensile properties of the steel fiber reinforced concrete(SFRC). Poly-linear approximation method combined with FEM analysis is applied to the steel fiber reinforced concrete to determine the tension softening diagrams and also to certify the validity of the method. The simulated load-CMOD curves using the determined softening diagrams though the poly-linear approximation method completely agree with the measured ones.

• Steel and Composite Structures
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• 제18권2호
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• pp.325-344
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• 2015

Experimental tests on cellular beams with sinusoidal openings showed two main failure modes around the openings. They concern the formation of four plastic hinges and the local instability of the sinusoidal part of the opening. In parallel, numerical analysis of the sinusoidal part of the opening revealed the existence of an elastic rotational restraint between the intermediate web-post and the adjacent opening panel. The aim of the present study is to present an approach to quantify this rotational restraint. Through the response surface method, a mathematical model is proposed. It shows a great ability to predict the rotational restraint value as a function of the geometrical parameters of the opening. This model can be used to perform an extensive study with various geometrical configurations of beams with the aim to develop a reliable and realistic analytical model predicting the resistance of the sinusoidal openings.

• Steel and Composite Structures
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• 제46권4호
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• pp.513-523
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• 2023

Buckling and post-buckling behaviors of geometrically perfect double-curvature shells made from smart composites have been investigated. The shell has been supposed to be exposed to transverse mechanical loading and magneto-electro-elastic (MEE) coupling. The composite shell has been made of two constituents which are piezoelectric and magnetic ingredients. Thus, the elastic properties might be variable based upon the percentages of the constituents. Incorporating small scale impacts in regard to nonlocal theory leads to the establishment of the governing equations for the double-curvature nanoshell. Such nanoshell stability will be shown to be affected by composite ingredients. More focus has been paid to the effects of small scale factor, electric voltage and magnetic intensity on stability curves of the nanoshell.

• Steel and Composite Structures
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• 제47권1호
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• pp.135-145
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• 2023

This study presents a numerical investigation into the hysteretic behavior of cold-formed austenitic stainless steel square hollow section (SHS) brace members using a commercial finite element (FE) analysis software ABAQUS/Standard. The initial/post buckling and fracture life of SHS brace members are comprehensively investigated through parametric studies with FE models incorporating ductile fracture model, which is validated against the existing laboratory test results collected from the literature. It is found that the current predictive models are applicable for the initial buckling strengths of SHS brace members under cyclic loading, while result in significant inaccuracy in predictions for the post-buckling strength and fracture life. The modified predictive model is therefore proposed and the applicability was then confirmed through excellent comparisons with test results for cold-formed austenitic stainless SHS brace members.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.25-26
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• 2021

System scaffolding and shoring are temporary structures in which vertical members, horizontal members, bracing members and trusses are assembled and installed. In order to ensure quality and safety, the quality test shall be carried out in accordance with the Guidelines for Quality Management of Construction Works (MOLIT Notice No. 2020-750). The quality test method (national standard) for Components for tied post system scaffolding and shoring is based on the Korean standards (KS F 8021) and the Safety certification standards (MOEL Notice No. 2021-22). However, the two standards differ in some aspects such as performance standards and etc, so cause confusion when applying them on-site. In addition, the standard for truss are applied only to trusses for shoring and cannot be applied to trusses for scaffolding. Therefore, this study aims to unify the two national standards and establish realistic standards.

• 한국구조물진단유지관리공학회 논문집
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• 제27권6호
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• pp.201-210
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• 2023

이 연구의 목적은 필로티 건축물에서 아라미드 섬유시트의 연성보강 효과를 평가하는데에 있다. 필로티 구조물은 총 2개가 제작되었으며, 반복 횡하중 정적 실험으로 휨 거동을 평가하였다. 연성보강 효과는 횡하중-변위관계, 변위연성비, 일손상지수 및 비틀림 거동으로부터 검증되었다. 실험결과 기둥이 아라미드 섬유시트로 보강된 필로티 건축물은 최대하중 이후 기둥에서 효과적인 구속효과로 전단파괴 방지 및 비틀림이 최소화되었으며, 전반적으로 연성적인 거동을 보였다. 결과적으로 기둥이 아라미드 섬유시트로 보강된 필로티 건축물의 변위연성비 및 일손상지수는 보강되지 않은 필로티 건축물보다 각각 4.63배 및 42.81배 높았다.

• Structural Engineering and Mechanics
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• 제48권6호
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• pp.791-807
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• 2013

Ultra High Performance Cementitious Composites with compressive strength 200MPa (UHPCC-200) is proposed for the structural design of super high hybrid wind turbine tower to gain durability, ductility and high strength design objectives. The minimal wall thickness is analyzed using basic bending and compression theory and is modified by a toque influence coefficient. Two cases of wall thickness combination of middle and bottom segment including varied ratio and constant ratio are considered within typical wall thickness dimension. Using nonlinear finite element analysis, the effects of wall thickness combinations with varied and constant ratio and prestress on the structural stress and lateral displacement are calculated and analyzed. The design limitation of the segmental wall thickness combinations is recommended.