• Earthquakes and Structures
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• v.10 no.3
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• pp.629-643
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• 2016

Among all the natural disasters, earthquakes are the most destructive calamities since they cause a plenty of injuries and economic losses leaving behind a series of signs of panic. The present study highlights the moment-curvature relationships for the structural elements such as beam and column elements and Non-Linear Static Pushover Analysis of RC frame structures since it is a very simplified procedure of non-linear static analysis. The highly popular model namely Mander's model and Kent and Park model are considered and then, seismic risk evaluation of RC building has been conducted using SAP 2000 version 17 treating uncertainty in strength as a parameter. From the obtained capacity and demand curves, the performance level of the structure has been defined. The seismic fragility curves were developed for the variations in the material strength and damage state threshold are calculated. Also the comparison of experimental and analytical results has been conducted.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.107-114
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• 1998

The solubilities of $CO_2$ in 20wt% and 30wt% aqueous AMP solution were obtained from experiments at 40, 50, 60, 70, $80^{\circ}C$. Using the modified Kent-Eisenberg model, equilibrium constants and correlations were determined from the regression of experimental results of 30wt% aqueous AMP solution. There were good agreements between the predicted $CO_2$ solubilities in 20wt% aqueous AMP solution and experimented values. The prediction was conducted at the condition in the literature and the predicted values calculated from the model and correlations which were obtained from this work agree well with the prediction from Deshmukh-Mather model. Thus, the modified Kent-Eisenberg model and correlated equations suggested by this work, resonably well represent vapor-liquid equilibrium of $CO_2$ with aqueous AMP solution. The calculation of chemical species concentration in the liquid phase was performed uslng equilibrium model and from this calculation, we confirm that good absorption capacity is due to the formation of unstable carbamate. Heat of solution(${\Delta}Hs$) was calculated from the solubility data using the Gibbs-Helmholtz equation.

• Journal of the Korean Institute of Gas
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• v.7 no.3 s.20
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• pp.7-12
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• 2003

A sour natural gas feed containing 1.37 and 1.70 mole percent $CO_2$ and $H_2S$ respectively is to be sweetened. Our research is to design an amine treating facility to bring the concentration of the acid gases in 100 MMSCFD of natural gas down to less than 5 ppm. The K-values for $CO_2,\;H_2S,\;H_2O$ and amine components contained in natural gas is obtained by using Kent-Eisenberg model. The new gas sweetening process designed by Ball and Veldman is modeled and optimized with the commercial simulator. Results of simulations led to further economic improvements over the present operating process.

• International Journal of Railway
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• v.3 no.2
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• pp.73-82
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• 2010

Global and local behaviors of a lightly RC shear walls are investigated in this paper. For the sake of cyclic behaviors, nominal ground accelerations of 0.15 g, 0.40 g and 0.55 g which associated with natural periods of the walls are applied as listed in French CAMUS-2000 shake table test. Modified Kent & Park model, Drucker-Prager model for concrete material and $Giufr\acute{e}$-Menegotto-Pinto model for rebar are used for time history analyses using fiber/solids elements respectively. Alternatively, Eulerian beam analysis are discussed by imposing inelastic hinges at the most possible plastic hinge location using modified Takeda's trilinear model with stiffness reduction. Relative displacements, base shears, bending moments of 5-story shear building with 36-tons of mass under bi-lateral seismic excitation are extracted and compared with EC-8, PS-92 and KBC-09 provisions. Multi-scaled degradation process; material damage, elemental fracture and structural failure in turn is discussed in the view of numerical accuracy, efficiency and limitation depending on three different model-based analyses.

• Structural Engineering and Mechanics
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• v.48 no.5
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• pp.587-613
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• 2013

A 3-node 3D co-rotational beam element using vectorial rotational variables is employed to consider the geometric nonlinearity in 3D space. To account for shape versatility and reinforced concrete cross-sections, fibre model has been derived and conducted. Numerical integration over the cross-section is performed, considering both normal and shear stresses. In addition, the derivations associated with material nonlinearity are given in terms of elasto-plastic incremental stress-strain relationship for both steel and concrete. Steel reinforcement is treated as elasto-plastic material with Von Mises yield criterion. Compressive concrete behaviour is described by Modified Kent and Park model, while tensile stiffening effect is taken into account as well. Through several numerical examples, it is shown that the proposed 3D co-rotational beam element with fibre model can be used to simulate steel and reinforced concrete framed structures with satisfactory accuracy and efficiency.

• The Research Journal of the Costume Culture
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• v.20 no.3
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• pp.451-462
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• 2012

Drawing on the literature on TAM and presence, this study proposes a model of the extended TAM by identifying factors that affect the motivations to enhance our understanding of online consumers' acceptance of an e-tail website. This study conceptualizes that consumers' perceived presence variables such as telepresence and social presence are the antecedents to the motivations of TAM. Empirical tests using regression analyses generally supported the proposed model. The overall conclusion from the current data is that our integrated model is useful in understanding consumers' acceptance of an apparel e-tail website. The findings show that perceived usefulness, perceived ease of use, and perceived interest motivations act as strong determinants of consumers' attitude toward an e-tailer, which leads to their behavioral intentions about the e-tailer. This suggests that apparel e-tailers should consider these three motivations when they design their websites. As one way to influence these three factors, this study showed the role of perceived presence in the usage of an apparel e-tail website. The findings suggest that online consumers' perceptions of "being there" and "socialness" stimulate their perceptions of usefulness and interest in the website use. Thus, e-tailers should consider effective ways to increase consumers' perceived presence.

• Earthquakes and Structures
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• v.26 no.1
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• pp.31-48
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• 2024

In order to get a better understanding of seismic performance of exterior beam-column joint, reciprocating loading tests with variable loading speeds or axial forces were carried out. The main findings indicate that only few cracks exist on the surface of the joint core area, while the plastic hinge region at the beam end is seriously damaged. The damage of the specimen is more serious with the increase of the upper limit of variable axial force. The deflection ductility coefficient of specimen decreases to various degrees after the upper limit of variable axial force increases. In addition, the higher the loading speed is, the lower the deflection ductility coefficient of the specimen is. The stiffness of the specimen decreases as the upper limit of variable axial force or the loading speed increase. Compared to the influence of variable axial force, the influence of the loading speed on the stiffness degradation of the specimen is more obvious. The cumulative energy dissipation and the equivalent viscous damping coefficient of specimen decrease with the increase of loading speed. The influence of variable axial force on the energy dissipation of specimen varies under different loading speeds. Based on the truss model, the biaxial stress criterion, the Rankine criterion, the Kent-Scott-Park model, the equivalent theorem of shearing stress, the softened strut-and-tie model, the controlled slip theory and the proposed equations, a calculation method for the shear capacity is proposed with satisfactory prediction results.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.578-588
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• 2002

An experimental study was conducted to investigate the effectiveness of transverse reinforcement in reinforced concrete tied columns subjected to monotonically increasing axial compression. Eighteen large-scale columns(260$\times$260$\times$1200 mm) were tested. Effects of main variables such as the concrete compressive strength, the tie configuration, the transverse reinforcement ratio, the tie spacing, and the spatting of the concrete cover were considered. High-strength concrete columns under concentric axial loads show extremely brittle behavior unless the columns are confined with transverse reinforcement that can provide sufficiently high lateral confinement pressure There is a consistent decrease in deformability of column specimen with increasing concrete strength. Test results were compared with the previous confinement model such as modified Kent-Park, Sheikh-Uzumeri, Mander, and Saatcioglu-Razvi model. The comparison indicates that many previous models for confined concrete overestimate or underestimate the ductility of confined concrete.

• Therapeutic Science for Rehabilitation
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• v.7 no.1
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• pp.79-88
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• 2018

Objective : Conventional therapy approaches for stroke survivors have required considerable demands on therapist's effort and patient's expense. Thus, new robotics rehabilitation therapy technologies have been proposed but they have suffered from less than optimal control algorithms. This article presents a novel technical healthcare solution for the real-time, simultaneous and propositional myoelectric control for stroke survivors' upper limb robotic rehabilitation therapy. Methods : To implement an appropriate computational algorithm for controlling a portable rehabilitative robot, a linear regression model was employed, and a simple game experiment was conducted to identify its potential of clinical utilization. Results : The results suggest that the proposed device and computational algorithm can be used for stroke robot rehabilitation. Conclusion : Moreover, we believe that these techniques will be used as a prominent tool in making a device or finding new therapy approaches in robot-assisted rehabilitation for stroke survivors.