• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.238-240
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• 2003

본 연구는 덕음광산 광미시료에 대한 각 pH별 중금속 거동 및 본 지역에서 중금속과 밀접한 관계를 가지는 토양광물인 Mn-함유광물의 용해도의 상관성을 규명하고자 한다. 본 연구를 통하여 Mn-함유광물의 용해도에 따른 중금속의 거동간의 상관관계를 알아봄으로서 광산 주변 지역의 지구화학적인 변화를 예측하고 오염지역 특성을 정확하게 이해할수 있도록 정보를 제공하고자 하였다. (중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.92-97
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• 1997

경수로용 전산코드인 ERAPCON2를 CANDU 핵연료의 거동에 사용하기 위하여 소결체-피복관틈새 열전도 모형과 소결체내 중성자속 분포 모형을 개조하였다. 기존의 CANDU핵연료 전산코드와 비교한 결과 CANDU핵연료의 열적거동 분석에 있어 거의 동일한 결과를 얻었다. 이를 사용하여 DUPIC 핵연료의 열적 거동특성을 알아보았다. 고용성 핵분열생성물에 의해 감소된 DUPIC 핵연료의 열전도도에 의하여 핵연료 중심부 온도가 증가됨을 알 수 있었다. 선출력 500W/cm에서 중심온도가 230-320K 정도 증가하였다. 따라서, DUPIC핵연료 설계에서 중심온도 증가에 대한 세밀한 분석이 요구된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.953-963
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• 1994

Treatment techniques of soft clay layers is needed sophisticated technology in civil engineering. Especially, dredged and reclaimed clay has high liquid limit and water content, so it is difficult to use. Now it comes to the applicability as good construction materials by predicting the behaviors. This paper is to evaluate the characteristics of sedimentation and self-weight consolidation of extremely soft clay, and is to find the way of applying model test result of reconstructing the in-situ condition to design. The consolidation properties of soft clay layers changing the size of the cell are investigated by large-scale consolidation test apparatus and the behaviors of self-weight consolidation are predicted by numerical analysis.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.167-170
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• 2004

본 논문에서는 수중익 버블 캐비테이션과 날개 끝 볼텍스 캐비테이션의 거동 및 소음을 Eulerian-Lagrangian 기법을 이용하여 수치적으로 해석하였다. Eulerian-Lagrangian 기법은 캐비테이션 버블이 유동장에 미치는 영향이 거의 없다는 가정하에 유동장과 캐비테이션 거동을 일방으로 연계하여 해석하는 방식이다. 수중익 버블 캐비테이션 해석을 위한 유동장은 비압축성 RAMS 방정식을 해석하여 구하고 날개 끝 볼텍스 캐비테이션 유동장은 일반적 CFD 기법의 큰 수치 소산으로 그 특성이 잘 나타나지 않으므로 Sculley 볼텍스 모델을 이용하여 해석한다. 해석한 유동장 정보를 입력치로 하고 버블의 지배 방정식인 Rayleigh-Plesset 방정식과 Newton의 제2법칙에 근거한 궤적 방정식을 연계하여 캐비테이션의 성장-붕괴와 운동을 예측한다. 계산된 거동 정보를 이용하여 버블 캐비테이션과 날개 끝 볼텍스 캐비테이션의 소음을 예측하였다. 본 연구는 수중 운동체에서 발생하는 캐비테이션의 거동과 소음의 특성을 파악하고 그에 따른 대비책을 마련하는 기본 연구로서 활용할 수 있을 것이다.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.2 s.2
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• pp.93-101
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• 2001

The objective of this study is to derive a shrinkage correction formula that considers temperature effect and to develop a methodology for the improved prediction of the long-term behavior of the FCM bridges by considering seasonal temperature variations in-situ. Thereby, current formulation were performed by using the actual experimental shrinkage data including seasonal temperature variation. The investigation of the long-term behavior of the FCM bridge was performed on the construction site in order to decide applicability of the shrinkage formula Numerical results by the general method indicates inaccurate values of total strain when considering real strain, whereas the applied method demonstrates a good agreement in the resultant strain. In consequently, the applied method will improve the prediction of the long-term deformation of the FCM Bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.6
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• pp.215-219
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• 2010

The evaluation of the mechanical properties and behavior is very important for the design of embankment using granular materials. In this research, the lab. tests with Nak-dong river sand were conducted to find out mechanical properties related to stress-strain behavior. Also, numerical simulations which can express the behavior of granular material were conducted by distinct element method. Distinct element method can play a import role to predict stress-strain behavior for different confining stress and loading condition if micro-parameters can be estimated in specific condition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5C
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• pp.183-190
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• 2009

It is necessary to predict the deformation and stresses on soils to establish the nonlinear stress-strain relationship of geomaterials at various strain levels. Especially, a need exists to establish the pre-failure nonlinear characteristic of cemented granular geomaterials used in road constructions. In this paper, therefore, conventional granular soils were mixed with various cementing materials, such as cement and fly ash from coal combustion by-products. Then, the normalized nonlinear behavior of cemented geomaterials was assessed using unconfined compression test. In addition, various constitutive models of soils were evaluated for estimating pre-failure non-linear behavior of cemented geomaterials from the test results.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.53-62
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• 2005

This paper estimates the long-term settlement of Kimpo metropolitan landfill based on measured settlement data from 180 landfill monitors accumulated over a period of 12 years. Comparison of domestic and international settlement records indicate that the domestic compression rate is slightly lower due to greater portion of organic component. Several existing settlement models are used to compare with the observed behavior and also to estimate long-term settlement. The hyperbolic, Gibson & Lo, Bjarngard & Edgers and Power Creep Law models compare well with the measured settlement of the Kimpo metropolitan landfill. The settlement models are further used to estimate long-term settlement. Bjarngard & Edgers and Power Creep Law models result in higher estimates of the long-term settlement compared to the hyperbolic and Gibson & Lo models. Further comparisons indicate that other models, including Sowers and log models, are inapproriate for predicting the long-term settlement of the Kimpo metropolitan landfill.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.3
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• pp.235-241
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• 2014

As a fiber-optic cable is being unwound, it is protected by a tube that is designed to prevent unwinding problems such as tangling and unintentional cutting. In addition, a guide body is separated from the protective tube if a shear pin breaks when the maximum allowable load is exceeded. Therefore, it is important to analyze and predict the unwinding behavior of the protective tube, as well as the load on the shear pin, to enhance the likelihood of a successful operation when laying cables at extreme depths. In this study, the protective tube and the guide body are modeled with particles and are constrained with a constant-length constraint. The load on the shear pin was verified against experimental data, and the unwinding behavior was predicted from the load prediction results.

• Magazine of the Korea Concrete Institute
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• v.8 no.3
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• pp.187-195
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• 1996

A finite element formulation based on the CFT(Compression Field Theory), considering the effect of compression softening in cracked concrete, and macro-scopic and rotating crack models etc., was presented for the nonlinear behaviour of structural concrete. Considering the computational efficency and the ability of modelling the post-ultimate behaviour as major concerns, the Incremental displacement solution algorithm involving initial material stiffnesses and the relaxation procedure for fast convergence was adopted and formulated in a type of 8-noded quadrilateral isoparametric elements. The analysis program NASCOM(Non1inear Analysis of Structural Concrete by FEM : Monotonic Loading) developed in this way enables the predictions of strength and deformation capacities in a full range, crack patterns and their corresponding widths, and yield extents of reinforcement. As the verification purpose of NASCOM, the predictions were made for Bhide's Panel(PB21) and Leonhardt's deep beam tests. The predicted results shows somewhat stiff behaviour for the panel test, and vice versa for deep beam tests. More refining process would be necessary hereafter in terms of more accurately simulating the effects of tension-stiffening and compression softening in concrete.