• Earthquakes and Structures
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• 제22권3호
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• pp.219-230
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• 2022

Knowing that the variability of soil properties is an important source of uncertainty in geotechnical analyses, we will study in this paper the effect of this variability on the seismic response of a structure within the framework of Soil Structure Interaction (SSI). We use the proposed and developed model (N2-ISS, Mekki et al., 2014). This approach is based on an extension of the N2 method by determining the capacity curve of the fixed base system oscillating mainly in the first mode, then modified to obtain the capacity curve of the system on a flexible basis using the concept of the equivalent nonlinear oscillator. The properties of the soil that we are interested in this paper will be the shear wave velocity and the soil damping. These parameters will be modeled at first, as independent random fields, then, the two parameters will be correlated. The results obtained showed the importance of the use of random field in the study of SSI systems. The variability of soil damping and shear wave velocity introduces significant uncertainty not only in the evaluation of the damping of the soil-structure system but also in the estimation of the displacement of the structure and the base-shear force.

• Structural Engineering and Mechanics
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• 제1권1호
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• pp.17-30
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• 1993

A practical multi-spring model is proposed for a nonlinear analysis of reinforced concrete members, especially columns, taking into account the interaction of axial load and bi-directional bending moment. The parameters of the model are determined on the basis of material properties and section geometry. The axial force-moment interaction curve of reinforced concrete sections predicted by the model was shown to agree well with those obtained by the flexural analysis utilizing realistic stress-strain relations of materials. The reliability of the model was also examined with respect to the test of reinforced concrete columns subjected to varying axial load and bi-directional lateral load reversals. The analytical results agreed well with the experiment.

• Rapid Communication in Photoscience
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• 제5권1호
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• pp.8-10
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• 2016

The potential curves of OH bonds of liquid water are inhomogeneous because of a variety of interactions with other molecules and this leads to a wide distribution of vibrational frequency which hampers our understanding of the structure and dynamics of water molecules. Mixed quantum/classical (QM/CM) calculation methods are powerful theoretical techniques to help us analyze experimental data of various vibrational spectroscopies to study such inhomogeneous systems. In a type of those approaches, the interaction energy between OH bonds and other molecules is approximately represented by the interaction between the charges located at the appropriate interaction sites of water molecules. For this purpose, we re-calculated the values of charges by comparing the approximate interaction energies with quantum chemical interaction energies. We determined a set of charges at the TIP4P charge sites which better represents the quantum mechanical potential curve of OH bonds of liquid water.

• 한국정밀공학회지
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• 제24권3호
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• pp.140-146
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• 2007

To understand adhesive phenomena, we need to get force curve between two surfaces. And it is said that high stiffness force analysis system is needed to get precise force curve and more information of the surfaces. Usually the stiffness of the force measurement system is under the order of 10N/m. The stiffer force measurement system, however, results in more information on the surface, because higher stiffness lead to the wider range of force curves, secondly because the force curve obtained through the stiffer one describes more precise relationship between relative tip-sample separation and interaction force. In this paper, considering for stiffness and resolution, the cantilever was designed and we made adhesion force measurement apparatus with high stiffness and high resolution, so we measured adhesive force between Ag-ball and wafer.

• Earthquakes and Structures
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• 제13권3호
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• pp.309-322
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• 2017

In this paper, a simplified evaluation method of the skeleton curve for reinforced concrete (RC) frame with unreinforced masonry (URM) infill is proposed in a practical form, based on the previous studies. The backbone curve for RC boundary frame was modeled by a tri-linear envelope with cracking and yielding points. On the other hand, that of URM infill was modeled by representative characteristic points of cracking, maximum, and residual strength; also, the interaction effect between RC boundary frame and the infill was taken into account. The overall force-displacement envelopes by the sum of RC boundary frame and URM infill, where the backbone curves of the infill from other studies were also considered, were then compared with the previous experimental results. The simplified estimation results from this study were found to almost approximate the overall experimental results with conservative evaluations, and they showed much better agreement than the cases employing the infill envelopes from other studies.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제2B권4호
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• pp.168-173
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• 2002

A new identification algorithm for the Preisach model is presented. The algorithm treats the identification procedure of the Preisach model as an inverse problem where the independent variables are parameters of the distribution function and the objective function is constructed using only the initial magnetization curve or only tile major loop of the hysteresis curve as well as the whole reversal curves. To parameterize the distribution function, the Bezier spline and Gaussian function are used for the coercive and interaction fields axes, respectively. The presented algorithm is applied to the ferrite permanent magnets, and the distribution functions are correctly found from the major loop of the hysteresis curve or the initial magnetization curve.

• Journal of Pharmaceutical Investigation
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• 제17권2호
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• pp.95-98
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• 1987

The drug interaction between probenecid and lithium carbonate was studied pharmacokinetically in rabbits. The blood level and the area under the concentration curve (AUC) of lithium carbonate administered orally were elevated by coadministration of probenecid. Probenecid inhibited the urinary excretion of lithium carbonate in rabbits. Biological half-life and $t_{max}$ of lithium carbonate were prolonged by coadministration of probenecid. From these results, dosage regimen of lithium carbonate is considered to be adjusted for effective and safe therapy in the coadministration of probenecid.

• 약학회지
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• 제27권2호
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• pp.133-138
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• 1983

The interaction between nalidixic acid and probenecid was studied pharmacokinetically in rabbits. The blood level and the area under the concentration curve(AUC) of nalidixic acid administered orally in dose of 100mg/kg was elevated by the coadministration of probenecid. Probenecid inhibited both the urinary excretion and the biliary excretion of nalidixic acid. Therefore, biological half-life of nalidixic acid was prolonged by the coadministrarion of probenecid. It was considered that the coadmini-stration of probenecid is more desirable than the single administration of nalidixic acid for the therapeutic effect.

• 한국지반환경공학회 논문집
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• 제19권10호
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• pp.35-41
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• 2018

구조물을 지지하는 말뚝기초에 대한 내진설계 시 안정을 위해 지반-기초-구조물의 동적 상호작용이 반드시 고려되어야 한다. 말뚝기초의 내진설계에 정적 및 반복하중 조건에서 제안된 p-y 곡선이 이용되고 있다. 이 p-y 곡선은 지진과 같은 동하중 조건에서 지반-기초-구조물의 상호작용이 고려되지 않았기 때문에 내진설계에 적용하기 어렵다. 이에 지반-기초-구조물의 동적 상호작용을 고려한 동적 p-y 곡선에 관한 연구가 수행되었으나 공통된 조건으로 말뚝 캡이 지표면 위에 노출되어 있고, 상부구조물은 단순 중량으로 말뚝 캡에 추가하여 동적 p-y 곡선을 확인하였다. 그러나 해양구조물인 경우를 제외한 보편적인 무리말뚝의 경우 지반에 근입하여 시공됨에 따라 말뚝 캡의 근입 여부가 말뚝의 동적 p-y 곡선에 영향을 미칠 것으로 보인다. 이에 본 연구에서는 말뚝 캡의 지반 근입에 따른 무리말뚝의 동적거동을 확인하기 위해 진동대 모형실험을 수행하였다. 그 결과 무리말뚝의 말뚝 캡이 지반에 근입된 경우와 근입되지 않은 경우의 동적거동은 다르게 나타났다.

• Interaction and multiscale mechanics
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• 제6권4호
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• pp.339-356
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• 2013

This paper investigates the optimized parameters of Tuned Mass Dampers (TMDs) for vibration control of high-rise structures including Soil Structure Interaction (SSI). The Artificial Bee Colony (ABC) method is employed for optimization. The TMD Mass, damping coefficient and spring stiffness are assumed as the design variables of the controller; and the objective is set as the reduction of both the maximum displacement and acceleration of the building. The time domain analysis based on Newmark method is employed to obtain the displacement, velocity and acceleration of different stories and TMD in response to 6 types of far field earthquakes. The optimized mass, frequency and damping ratio are then formulated for different soil types; and employed for the design of TMD for the 40 and 15 story buildings and 10 different earthquakes, and well results are achieved. This study leads the researchers to the better understanding and designing of TMDs as passive controllers for the mitigation of earthquake oscillations.