• Steel and Composite Structures
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• v.20 no.2
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• pp.337-355
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• 2016

Steel coupling beam in reinforced concrete (RC) coupled shear wall system is a proper substitute for deep concrete coupling beam. Previous studies have shown that RC coupled walls with steel or concrete coupling beam designed with strength-based design approach, may not guarantee a ductile behavior of a coupled shear wall system. Therefore, seismic performance evaluation of RC coupled shear wall with steel or concrete coupling beam designed based on a strength-based design approach is essential. In this paper first, buildings with 7, 14 and 21 stories containing RC coupled shear wall system with concrete and steel coupling beams were designed with strength-based design approach, then performance level of these buildings were evaluated under two spectrum; Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE). The performance level of LS and CP of all buildings were satisfied under DBE and MCE respectively. In spite of the steel coupling beam, concrete coupling beam in RC coupled shear wall acts like a fuse under strong ground motion.

• Interaction and multiscale mechanics
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• v.4 no.3
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• pp.173-185
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• 2011

A multiscale modeling scheme that addresses the influence of the nanoparticle size in nanocomposites consisting of nano-sized spherical particles embedded in a polymer matrix is presented. A micromechanics-based constitutive model for nanoparticle-reinforced polymer composites is derived by incorporating the Eshelby tensor considering the interface effects (Duan et al. 2005a) into the ensemble-volume average method (Ju and Chen 1994). A numerical investigation is carried out to validate the proposed micromechanics-based constitutive model, and a parametric study on the interface moduli is conducted to investigate the effect of interface moduli on the overall behavior of the composites. In addition, molecular dynamics (MD) simulations are performed to determine the mechanical properties of the nanoparticles and polymer. Finally, the overall elastic moduli of the nanoparticle-reinforced polymer composites are estimated using the proposed multiscale approach combining the ensemble-volume average method and the MD simulation. The predictive capability of the proposed multiscale approach has been demonstrated through the multiscale numerical simulations.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.11a
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• pp.445-453
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• 2002

Past and current customer behavior is the best predicator of future customer behavior. This paper introduces a procedure on personalized defection detection and prevention for an online game site. The basic idea for our defection detection and prevention is adopted from the observation that potential defectors have a tendency to take a couple of months or weeks to gradually change their behavior (i.e. trim-out their usage volume) before their eventual withdrawal. For this purpose, we suggest a SOM (Self-Organizing Map) based procedure to determine the possible states of customer behavior from past behavior data. Based on this representation of the state of behavior, potential defectors are detected by comparing their monitored trajectories of behavior states with frequent and confident trajectories of past defectors. The key feature of this study includes a defection prevention procedure which recommends the desirable behavior state for the ext period so as to lower the likelihood of defection. The defection prevention procedure can be used to design a marketing campaign on an individual basis because it provides desirable behavior patterns for the next period. The experiments demonstrate that our approach is effective for defection prevention and efficient for defection detection because it predicts potential defectors without deterioration of prediction accuracy compared to that of the MLP (Multi-Layer Perceptron) neural network.

• Earthquakes and Structures
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• v.12 no.5
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• pp.489-499
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• 2017

The effects of past earthquakes have demonstrated the seismic vulnerability of confined masonry structures (CMSs) to earthquakes. The results of experimental analysis indicate that damage to these structures depends on lateral displacement applied to the walls. Seismic evaluation lacks an analytical approach because of the complexity of the behavior of this type of structure; an empirical approach is often used for this purpose. Seismic assessment and risk analysis of CMSs, especially in area have a large number of such buildings is difficult and could be riddled with error. The present study used analytical and numerical models to develop a simplified nonlinear displacement-based approach for seismic assessment of a CMS. The methodology is based on the concept of ESDOF and displacement demand and is compared with displacement capacity at the characteristic period of vibration according to performance level. Displacement demand was identified using the nonlinear displacement spectrum for a specified limit state. This approach is based on a macro model and nonlinear incremental dynamic analysis of a 3D prototype structure taking into account uncertainty of the mechanical properties and results in a simple, precise method for seismic assessment of a CMS. To validate the approach, a case study was considered in the form of an analytical fragility curve which was then compared with the precise method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.719-727
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• 2013

Four-step travel-demand modeling based on a trip-level has been widely used over many decades. However, there has been a wide variance between forecasted- and real-travel demands, which leads less reliable on the model implications. A primary reason is that person's real travel behavior is not properly captured throughout the model developments. An activity-based modeling (ABM) approach was proposed and developed toward increasing the accuracy and reality of person's travel behavior in the U.S. since 1990', and stands as a good alternative to replace the existing trip-based approach. The paper contributes to the understanding of how the ABM approaches are dissimilar to the trip-based modeling approach in terms of estimation units, estimation process, their pros and cons and etc. We examined three activity-based travel demand model systems (DaySim, CT-Ramp, and CEMDAP) that are most commonly applied by many MPOs (Metropolitan Planning Organization). We found that the ABM approach can effectively explain multi-dimensional travel decision-makings and be expected to increase the predictive accuracy. Overall, the ABM approach can be a good substitute for the existing travel-demand methods having unreliable forecasts.

• Journal of Digital Contents Society
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• v.12 no.2
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• pp.185-194
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• 2011

This paper introduces a Statecharts-based progressive behavior LOD model for computer games and virtual reality systems. In order to use computing resources efficiently and generate an LOD model having arbitrary complexity, we defined a progressive behavior LOD model which including a Statecharts-based specification process, refinement operations, a switching policy, and an LOD selection policy. Additionally, in order to show the possibility of the proposed approach, we demonstrate an example of progressive LOD models by illustrating a step-by-step design of a virtual vehicle.

• Tunnel and Underground Space
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• v.34 no.2
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• pp.127-142
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• 2024

The robustness of a numerical method means that its computational performance is maintained under various modeling conditions. New numerical methods or codes need to be assessed for robustness through benchmark testing. The TOUGH-FLAC modeling approach has been applied to various fields such as subsurface carbon dioxide storage, geological disposal of spent nuclear fuel, and geothermal development both domestically and internationally, and the modeling validity has been examined by comparing the results with experimental measurements and other numerical codes. In the present study, a benchmark test of the TOUGH-FLAC approach was performed based on a coupled thermal-hydro-mechanical behavior problem with an analytical solution. The analytical solution is related to the temperature, pore water pressure, and mechanical behavior of a fully saturated porous medium that is subjected to a point heat source. The robustness of the TOUGH-FLAC approach was evaluated by comparing the analytical solution with the results of numerical simulation. Additionally, the effects of thermal-hydro-mechanical coupling terms, fluid phase change, and timestep on the computation of coupled behavior were investigated.

• Korean Journal of Childcare and Education
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• v.12 no.1
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• pp.1-17
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• 2016

The objective of the study is to find out the effects of toddler's temperament and mother's parenting behavior on the development of vocabulary ability. The study was conducted with 299 infants between the ages of 18 and 24 months and their mothers in 47 day care centers in I city, Jeollabukdo. The results of the study are as follows. First, according to the correlation between infant's temperament and vocabulary based on the composition of temperament, approach-avoidance, adaptability, and mood showed a negative correlation with receptive and expressive vocabulary, and response intensity showed a positive correlation with receptive vocabulary. Second, according to the relation between mother's parenting behavior and infant's vocabulary ability based on the sub-factors of mother's parenting behavior, instructional parenting behavior and setting-limits parenting behavior showed a positive correlation with receptive and expressive vocabulary. Third, according to the effects of infant's temperament and mother's parenting behavior on the development of infant's vocabulary ability, as for the understanding of vocabulary, the explanation power of approach-avoidance is the highest, followed by instructional parenting behavior, response intensity, and mood. As for expressive vocabulary, the explanation power of instructional parenting behavior is the highest, followed by mood, response intensity and activity. In the development of infant's vocabulary ability, it was found that receptive vocabulary was affected the most by approach-avoidance, and expressive vocabulary was affected the most by instructional parenting behavior. Mothers will have to have interrelation skills suitable for temperament for the development of infant's receptive vocabulary, and have parenting behavior expressing the traits of things and events for the development of expressive vocabulary.

• Structural Engineering and Mechanics
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• v.83 no.5
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• pp.609-615
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• 2022

A numerical approach for dynamic stability analysis of sandwich plates has been provided using Chebyshev-Ritz-Bolotin approach. The sandwich plate with porous core has been formulated according to a higher-order plate. All of material properties are assumed to be dependent of porosity factor which determines the amount or volume of pores. The sandwich plate has also been assumed to be under periodic in-plane loading of compressive type. It will be shown that stability boundaries of the sandwich plate are dependent on static and dynamical load factors, porosity factor, porosity variation and core thickness.

• Korean Institute of Interior Design Journal
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• no.28
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• pp.60-67
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• 2001

Built-up environments by humans are cultural byproducts which combine social ideology and architectural paradigm. The process of modernization in the Western countries has the characteristic of decisive paradgm based on materialism. Therefore, environmental design in modern world failed to focus on the essential features of humanity which are the subject of space and replaced it for objective and unilateral architectural environments, instead. Environment without supporting the human psychological and complicated behaviorism is as same as the hardware without the vitality. under these regards, this study will cover the design approach of pattern language as a design method of environment design. The purpose of design approach by pattern language lies in creating the space of flexibility, adaptability and strong vitality. It is summed up as humanization in space and it helps the user to verbalize individualized space language for their own. The range and method of in the study attribute to the pattern language of Christopher Alexander and a researcher' method on them. In premise that human behavior ought to the multilateral and indefinite under rapid change of circumstances in modern world, th study tried to find the design method stimulating creative behavior of human being.