• Computers and Concrete
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• v.12 no.3
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• pp.303-318
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• 2013

The purpose of this study is to present different composed material models for reinforced concrete structures (RC). For this aim a nonlinear finite element analysis program is coded in MATLAB. This program contains several yield criteria and stress-strain relationships for compression and tension behavior of concrete. In this study, the well-known criteria, Drucker-Prager, von Mises, Mohr Coulomb, Tresca, and two new criteria, Hsieh-Ting-Chen and Bresler-Pister, are taken into account. It is concluded that the coded program, the new yield criteria, and the models considered can be effectively used in the nonlinear analysis of reinforced concrete beams.

• Korean Journal of Child Studies
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• v.28 no.3
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• pp.77-100
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• 2007

This study investigated child's self-esteem by the mediational role of mother's parenting self-efficacy and its relations to perceived social support, parenting behavior, and stress, and to child's temperament and gender. Participants were 403 Korean children(188 boys, 215 girls) and their mothers living in Seoul. Structural equation modeling for boys and girls and their mothers indicated that parenting self-efficacy mediated the relation between social support and parenting behaviors including Warmth-Acceptance and Rejection-Restriction. In these models, parenting self-efficacy related to child's self-esteem through parenting behavior. Child's temperament related to self-esteem directly in three parenting behavior models. In Permissiveness-Nonintervention, parenting self-efficacy mediated between social support and self-esteem in both boy's and girl's models, between child's temperament and self-esteem in only boy's model.

• Asian Journal for Public Opinion Research
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• v.8 no.2
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• pp.144-159
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• 2020

This paper investigated the impact of grit on sustainable behavior and emotional well-being. A questionnaire about grit, sustainable behavior, and emotional well-being was administered to 273 undergraduate students in South Korea. To examine the association between the variables, this study used two spell out (SEM) comparison models. The results show that grit is positively related to sustainable behavior and emotional well-being. The effect of grit on emotional well-being was mediated by sustainable behavior. The effect of grit is higher on sustainable behavior than emotional well-being. In addition, sustainable behavior has a positive relationship to emotional well-being. The results show that the grit has an important implication for sustainable environment education and individual well-being.

• Journal for History of Mathematics
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• v.33 no.3
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• pp.167-177
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• 2020

Cooperative behavior may seem contrary to the notion of natural selection and adaptation, but is widely observed in nature, from the genetic level to the organism. The origin and persistence of cooperative behavior has long been a mystery to scientists studying evolution and ecology. One of the important research topics in the field of evolutionary ecology and behavioral ecology is to find out why cooperation is maintained over time. In this paper we take a historical overview of mathematical models representing cooperative relationships from the perspective of mathematical biology, which studies population dynamics between interacting biological groups, and analyze the mathematical characteristics and meanings of these cooperative models.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.1
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• pp.43-51
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• 2013

In this paper, analytical models for reinforced concrete shear wall systems designed based on Korean Building Code (KBC2009) are proposed, which have special and semi-special seismic details and are compared with experimental results for a verification of analytical models. In addition, semi-special seismic details aimed to improve constructability and enhance economic efficiency were proposed and evaluated. The analytical models were performed based on nonlinear static and dynamic analysis. Through the nonlinear analyses, two seismic details showed the similar seismic behavior from the cyclic test and the analytical models for the two different seismic details represented the behavior in terms of the initial stiffness, maximum strength and strength degradation. And newly proposed seismic details(semi-special) provided with similar hysterestic behavior as well as the maximum drift.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.453-458
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• 2001

This paper presents the procedure to find the hysteresis loop of RC member using a modified strut-and-tie model. The forces and displacements at critical points, that are initial yielding point, target displacement point, unloading elastic limit, and reloading point after pinching, are investigated with the strut-and-tie models. Using bond-slip relationship, the elastic behavior of tie element is determined. The plastic flow behavior after flexural yielding is expressed by changing the location of longitudinal strut. Determination of pinching effect completes the initial hysteresis loop, assuming that the behavior of the opposite direction is symmetrical form.

• Transactions of Materials Processing
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• v.14 no.8 s.80
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• pp.718-724
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• 2005

An efficient finite element method has been introduced for analysis of metallic sandwich plates subject to bending moment. A full model 3-point bending FE-analysis shows that the plastic behavior of inner structures appears only at the load point. The unit structures of sandwich plates are defined to numerically calculate the bending stiffness and strength utilizing the recurrent boundary condition for pure bending analysis. The equivalent models with the same bending stiffness and strength of full models are then designed analytically. It is demonstrated that the results of both models are almost the same and the FE-analysis method incorporating the equivalent models can reduce the computation time effectively. The dominant collapse modes are face buckling and face yielding. Since the inner dimpled structures prevent face buckling, sandwich plates with inner dimpled shell structure can absorb more energy than other types of sandwich plates during the bending behavior.

• Computers and Concrete
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• v.21 no.4
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• pp.385-397
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• 2018

This study is focused on the investigation for similitude the requirements between prototype and scaled models to determine the structural behavior of concrete load bearing systems. The scaling concept has been utilized in many engineering branches, has been assisted to engineers and scientists for obtain the behavior of the prototype by using scaled model. The scaling can be done for two purposes, either scaling up or scaling down depending upon the application. Because, scaled down models are the experimentation on scaled models is cheaper than huge structures. These models also provide facilities for experimental work. Similarity relationships between systems are created either by field equations of the system or by dimensional analysis. Within this study, similarity relationships were obtained by both methods. The similarity relations obtained are applied to different load bearing systems and it is determined that the similarity relation is a general expression. In this study, as an example, column, frame, cantilever beam and simple beam are chosen and 1/2, 1/5 and 1/10 scales are applied. The results are compared with the analytical results which are obtained by creating of the finite element models with SAP2000 software of different scaled load bearing systems. The analysis results of all systems are examined and it is determined that the scale factors are constant depending on the scale types for different load bearing systems.

• Journal of the Korea Safety Management & Science
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• v.8 no.1
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• pp.85-96
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• 2006

The oriental life change unit(LCU) models differ from the western LCU model in human behavior, life style, ideas, culture, and psychology factors. Especially, the cause and effect models by behavior scientific approach method have provided the accident proneness concept through the LCU factors. Therefore this paper describes the analytical results of the oriental LCU model and western LCU model. Especially, the death of parents and death of close friend in Korean LCU model feel more acute stress than the western factors. In the case of Korean LCU models between the unmarried and married workers living in the middle area of Korea, death of parents, change in family member's health, change to different line of work, and change in work hours and condition are significant at the significance level of 5%. The priority of life change factors in these models is approved in the order of death of parents, death of spouse, death of close family member, and death of close friend. Finally, the result of this paper can be easily used in order to minimize the industrial accidents by the job stress with the worker and safety manager in real fields.

• International Journal of Human Ecology
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• v.17 no.1
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• pp.1-14
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• 2016

This paper presents a series of path models that were developed to test whether financial risk tolerance mediates the association between the following four variables and investing behavior: (a) male and married, (b) female and married, (c) male and single, or (d) female and single. Data for this study were obtained from a proprietary consumer survey of risk-tolerance attitudes. Four path models were developed to test relationships among the variables in 2008, 2009, 2010, and 2011. These years were chosen to represent the depth and recovery periods in the Great Recession. The total number of respondents was 29,641. Findings showed that financial risk tolerance was positively associated with risky investing behavior (i.e., equity ownership) in each of the four periods. The associations among the gender-marital status variables and investing behavior were mixed; however, findings did indicate that risk tolerance mediates these relationships by sometimes amplifying and occasionally attenuating risky behavior. Based on the findings, implications and limitation are presented.