• Smart Structures and Systems
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• 제24권4호
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• pp.491-506
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• 2019

Literature regarding concrete walls reinforced by super elastic shape memory alloy (SMA) bars is rather limited. The seismic behavior of a system concurrently including a distinct steel reinforced concrete (RC) wall, as well as another wall reinforced by super elastic SMA at the first story, and steel rebar at upper stories, would be an interesting matter. In this paper, the seismic response of such a COMBINED system is compared to a conventional system with steel RC concrete walls (STEEL-Rein.) and also to a wall system with SMA rebar at the first story and steel rebar at other stories ( SMA-Rein.). Nonlinear time history analysis at maximum considered earthquake (MCE) and design bases earthquake (DBE) levels is conducted and the main responses like maximum inter-story drift ratio and residual inter-story drift ratio are investigated. Furthermore, incremental dynamic analysis is used to accomplish probabilistic seismic studies by creating fragility curves. Results demonstrated that the SMA-Rein. system, subjected to DBE and MCE ground motions, has almost zero and 0.27% residual maximum inter-story drifts, while the values for the COMBINED system are 0.25% and 0.51%. Furthermore, fragility curves show that using SMA rebar at the base of all walls causes a larger probability of exceedance 3% inter-story drift limit state compared to the COMBINED system. Static push over analysis demonstrated that the strength of the COMBINED model is almost 0.35% larger than that of the two other models, and its general post-yielding stiffness is also approximately twice the corresponding stiffness of the two other models.

• 한국소음진동공학회논문집
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• 제22권10호
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• pp.959-967
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• 2012

The theory for a new electromagnetically biased diskless combined radial and axial magnetic bearing is developed. A typical magnetic bearing system is composed of two radial magnetic bearings and an axial magnetic bearing. The axial magnetic bearing with a large axial disk usually limits rotor dynamic performance and makes assembling and disassembling difficult for maintenance work. This paper proposes a novel electromagnet biased integrated radial-axial magnetic bearing without axial disk. This integrated magnetic bearing uses two axial coils to provide the bias flux to the radial and axial air gaps of the combined bearing. The axial magnetic bearing unit in this combined magnetic bearing utilizes reluctance forces developed in the non-uniform air gaps such that the axial disk can be removed from the bearing unit. The 4-pole homopolar type radial magnetic bearing unit is also designed and analyzed. Three dimensional finite element model for the bearing is also developed and analyzed to illustrate the diskless combined magnetic bearing.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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• pp.35-42
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• 1995

One of the main objectives of this study is to propose a realistic limit state model for reliability-based safety assessment of precast segmental prestressed concrete box girder bridges, considering 1) combined effects of bending, shear and torsional forces, and 2) the difference between transverse reinforcments of box girder. A improved limit state model is derived from a modified interaction equation compared with the Bruno's equation. A Drectional sampling algorithm is used for reliability analysis of the proposed model.

• 산업경영시스템학회지
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• 제18권34호
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• pp.9-14
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• 1995

A cost minimization model for designing AS/RS (Automated Storage/Retrieval Systtems) has been developed under the S/R (Storage/Retrieval) machine throughput rate and total storage capacity requirements. The objective function includes S/R machine cost storage rack cost, and interface conveyor cost. Since the model is a nonlinear integer programming problem which is very hard to solve with large problem size, the model is simplified using previous research results to be solved exactly and a simultion procedure is combined to verify that throughput rate requirements are satisfied.

• 혜화의학회지
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• 제17권2호
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• pp.117-135
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• 2008

In order to investigate the efficacy of a combination of JBB as topical and HTGMB as internal treatment method, changes in various immune related factors and histological changes in NC/Nga induced animal model was studied. Combined treatment of topical JBB and internal HTGMB significantly reduced the atopic dermatitis clinical index, the number of immune cells such as CD19+, CCR3+, B220+/IgE+, and Gr-1+/CD11b+ in DLN and dorsal skin, compared to the control group. Otherwise increased CD3+, CD4+/CD25+, CD8+ and CD4+ cells in the DLN. And also combined treatment of topical JBB and internal HTGMB suppressed the lymphocytes and mast cells from infiltrating into the skin tissues when stained with H&E and toluidine blue. Based on the results above, it is strongly suggested that the combined treatment of topical JBB and internal HTGMB significantly induced anti-allergic activities through immune modulation. The findings can be applied to developing a more sustainable treatment for atopic dermatitis and be helpful in practicing combined treatments in clinical treatments in the future.

• 한국자동차공학회논문집
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• 제13권1호
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• pp.76-82
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• 2005

In this paper, validation of Driver Steering Model has been conducted. The comparison between the simulation model and vehicle test results shows that the model is very feasible for describing combined human driver and actual vehicle dynamic behaviors. The 3D vehicle model is consisted of 6-DOF sprung mass and 4-quarter car model for vehicle body dynamics. Powertrain model including differential gear and Pacejka tire model are applied. The driver steering model is also validated with vehicle test result. The driver steering model is based on angle and displacement error from the desired path, recognized by driver.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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• pp.178-184
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• 1995

A new combined isotropic/kinematic and orthotropic hardening viscoplastic model is proposed which can account for not only differential orientations but also preferred orientations of grains in n metal at finite plastic deformations with an introduction of multiple spin (rate of rotation) concept within the general framework of the model, the effects of anisotropy and constitutive spins will be discussed in conjunction with a closed-form solution for simple shear in n rigid-plastic material, which will be used to simulate experimental data of Montheillet, et al. (1984) for fixed-end tortion tests at finite plastic deformations.

• 대한환경공학회지
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• 제35권11호
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• pp.785-794
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• 2013

합류식하수관로시스템에서 강우시 유출수는 관로내 퇴적물과 지표면 세척효과에 의한 오염물질 등이 혼합되어 하천으로 방류되기 때문에 방류수계에 화학적 물리적 생물학적으로 상당한 문제를 야기하지만, 현재 국내에서는 CSOs의 오염 부하량 관리기준을 결정함에 있어 통일된 방법론이 부재한 실정이다. 이에 따라 본 연구에서는 우수유출모형을 활용한 장기간 CSOs 유량-수질모의를 통하여 CSOs의 오염부하량 저감목표를 설정하고자 한다. 이를 위하여 국내외 CSOs 관리기준을 검토하였으며, 그 결과 연간 총 월류부하량 및 발생빈도를 총 2단계로 구분하여 관리하고, 1단계에서는 60%, 2단계에서는 85%를 저감하는 것을 목표로 설정하였다. 도출된 저감 목표 기준을 대상지역에 적용하여 장기간(최소 10년간)의 CSOs 발생 모의를 바탕으로 분석한 결과, BOD 월류부하량 저감목표는 1단계 1,123 kg, 2단계 2,374 kg이었으며, 목표 달성을 위해 대응해야 할월류량은 1단계 $11,685m^3$, 2단계 $24,701m^3$으로 나타났다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.210-217
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• 2011

Purpose: This study was to evaluate the synergistic effects of combined therapy of steroid and anti-neoplastic drug injection on hypertrophic scars in a rabbit model. Methods: Adult male white rabbits weighing about 2.5 kg were used. After full thickness wounding (about 6 mm) over the ventral surface of each ear sized was made, either saline (control group), triamcinolone, 5-fluoruracil, and mixture of triamcinolone and 5-fluoruracil were injected once 16 days after the wound was made. Rabbits were sacrificed 2, 4 and 8 weeks after injection, and tissue specimens were prepared for histologic and histomorphometric examinations. Results: With the combined injection of triamcinolone and 5-fluoruracil, collagen fiber thickness was arranged in a somewhat irregular manner 2 weeks after injection. After 4 weeks, blood vessels and inflammatory cells were decreased, and collagen fibers were arranged in an almost parallel manner. By 8 weeks, almost same amount of connective tissue compared with adjacent normal tissue was observed. Conclusion: These results indicated that combined injection of triamcinolone and 5-fluoruracil reduced the amount of hypertrophic scars by inhibition of fibroblasts and inflammatory cells. Therefore, combined injection of triamcinolone and 5-fluoruracil is a more potent and effective treatment of hypertrophic scars compared with the single injection of either triamcinolone or 5-fluorouracil.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.258-258
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• 2018

In this study, a hydraulic flow model and an error correction model are combined to improve the flood simulation accuracy. First, the hydraulic flow model is calibrated by optimizing the Manning's roughness coefficient that considers spatial and temporal variability. Then, an error correction model were used to correct the systematic errors of the calibrated hydraulic model. The error correction model is developed using Artificial Neural Networks (ANNs) that can estimate the systematic simulation errors of the hydraulic model by considering some state variables as inputs. The input variables are selected using parital mutual information (PMI) technique. It was found that the calibrated hydraulic model can simulate flood water levels with good accuracy. Then, the accuracy of estimated flood levels is improved further by using the error correction model. The method proposed in this study can be used to the flood control and water resources management as it can provide accurate water level eatimation.