• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.06a
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• pp.123-134
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• 1997

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.06a
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• pp.101-111
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• 2004

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.196-202
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• 1999

Purpose : When the mature kidney fails to reach its norml location in the renal fossa, the condition is known as ectopic kidney. Presenting symtoms can be various and it generally depend on the associated anomaly. Beside urologic anomalies such as hydronephrosis and vesicoureteral reflux, various anomalous vascular net work, skeletal anomaly or genital anomaly can be observed in this condition. Methods : Sixteen children with ectopic kidney was studied retrospectively to analyse initial presentation, accompanied anomaly and prognosis. Results : 56% of the children were accompanied with other urologic anomalies such as true incontinence and vesicoureteral reflux that required surgical treatment. 31% of children were either diagnosed incidentally during evaluation of other non-urologic disease or during follow-up evaluation of abnormal antenatal renal sonogram. Conclusion : Ectopic kidney can be often misdiagnosed as tumorous condition or as a surgical condition depend on the abnormal location of the kidney. Careful evaluation using abdominal sonogram, DMSA, VCUG and abdominal CT scan should be performed in order to search for associated anomalous condition and for proper management.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.802-804
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• 2007

Although intrathoracic liver in association with a congenital diaphragmatic hernia has been well documented, the finding of intrathoracic ectopic liver tissue in the presence of an intact diaphragm is an extremely rare congenital anomaly. We have experienced a case of intrathoracic ectopic liver without any diaphragmatic hernia. A 37-year-old woman was admitted for the treatment of an incidentally detected right lung mass, A chest computed tomography scan revealed a right lower lobe lung mass close to the diaphragm, and this was suspicious for bronchial carcinoid tumor. Upon surgery, 2 round solid masses $3.5{\times}3.5 cm$ and a $2.0{\times}2.0 cm$ in size were noted, with their bottoms attached to the diaphragm dome. The masses were completely resected. Histologically, they were confirmed to be intrathoracic ectopic livers. The patient had an uncomplicated postoperative course.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.547-555
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• 2011

An unstiffened top and seat angle connection is a type of partially restrained connection that is suitable for low- and medium-rise steel buildings. The plastic moment resisting capacity of such connection is needed in practical design, in addition to the accurate prediction of the initial rotational stiffness. Therefore, most of the studies conducted for the mentioned connections were performed to predict the initial stiffness and the plastic moment resisting capacity with varying geometric properties. The main parameters of such experimental tests were the thickness and high-strength bolt gauge distance of AISC LRFD-type A top and seat angle connections. Based on the test results, the analytical model was also proposed in this study. The applicability of the proposed model was verified by comparing the test results from this study with those of other studies.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.1
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• pp.59-65
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• 2004

Recently, as steel structures become higher and more long-spanned, application of high strength steel. SM570, is considered, For accurate seismic design, seismic analysis of steel structures needs a constitutive equation describing the characteristic of steel materials under non-proportional cyclic loading, While the use of SM570 material is much increased these days, research for description and generalization of cyclic plasticity behavior are insufficient, In this study, a cyclic plasticity model is proposed by results of material tests, i.e, monotonic and low cycle tests, Proposed cyclic plasticity model is applied to 3-Dimensional FE program and we carried out seismic analysis of pipe-section steel pier using SM570, Comparison between experiment and analysis results shows that the proposed constitutive equation is able to describe exactly the complicated plastic behavior of steel structure using SM570.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.3
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• pp.361-371
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• 2000

RC structure is the composite material system combined concrete and steel showing different plastic behavior. Especially, concrete shows very complex plastic behavior. Therefore, for plastic analysis of RC structures, we have to model carefully each plastic behavior of concrete and steel member. But, because of divergency as well as difficulties and dimensions of modelling, it takes a lot of time and labor or sometimes it is impossible to perform plastic analysis of RC structures. In this study, for simplified plastic analysis of RC structures, we propose material transformation method by homogeneous and isotropic material which have the same plastic property as RC. We generate homogeneous and isotropic material showing the same moment-curvature curves (bi-linear stress-strain relation) as RC members, using bi-linear moment-curvature relation by yielding moment, yielding curvature and ultimate moment, ultimate curvature of RC member. Finally, we prove compatibility in the study by comparing plastic analysis results for various analysis models using transformed material models and RC model.

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.25-31
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• 2009

In general, it is well known fact that the stone mastic asphalt (SMA) pavement has a high resistance against rutting. However, performance of SMA is not well measured by general method used in the laboratory. The objective of this study is to investigate an applicability of deformation strength ($S_D$) for performance estimation of SMA, and to find out the correlation between rut depth and dynamic stability, and $S_D$ of SMA. This study carried out wheel tracking test and Kim-test with optimum asphalt content (OAC) determined by mix design. The results indicated that the $S_D$ of SMA was very poorer than those of dense-graded asphalt mixtures. $S_D$ showed similar WT dynamic stability and rut-depth level. It was found that Kim-test was not reflected higher rutting resistance of SMA like as indirect tensile strength (ITS) test and Marshall stability test. Also, it was revealed that dynamic stability and rut-depth of WT had some problems to estimate rutting resistance of SMA mixtures.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1657-1664
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• 1991

본 연구에서는 재료의 이방성을 고려한 점소성 모델을 제시하였다. 공학적 인 견지에서 볼 때 이방성 재료의 기계적 거동을 표한하기 위해서는 단순화 이론(si- mplified theory)의 개발이 필요하게 되었으며 이에따라 Betten은 등방성 소성 포텐셜 (isotropic plastic potential)에서 응력텐서를 재료의 이방성을 포함하는 변환 응력 텐서(mapped stress tensor)로 대체함으로써 이방성을 고려하였다. 그러므로 실제 이방성 재료의 비탄성 거동은 가상의 등방성 상태로 치환되며 여기에 소성 포텐셜 이 론을 적용하게 된다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.3
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• pp.443-452
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• 1992

본 연구에서는 소성가공 공정의 최적설계를 위한 새로운 접근 방법이 소개 된다.이방법은 소성가공 공정의 유한요소해석 기술과 기계시스템의 최적설계 기술 에 바탕을 두고 있다. 벌칙 강소성유한요소법, 정상 상태의 소성가공 공정(steady -state metal forming process)을 위한 최적설계 문제의 수식화, 설계민감도의 해석 방법, 설계민감도의 정확성에 관한 고찰, 구배투영법(gradient projection emthod)등 이 본 논문에서 상세하게 소개된다.