• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.2
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• pp.115-131
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• 2011

Recently, considering the aspects of disaster prevention and environmental damage, the construction of a twin tunnel is increasing. When constructing a twin tunnel, the stresses are concentrated at the pillar so that stability of the tunnel is decreased. Since the previous studies on the behavior of a twin tunnel pillar are mainly restricted to the estimation of the tunnel behavior and the analysis of surface settlement, there is a limit to a quantitative stability estimation of the pillar. Therefore, it was quantitatively investigated how the pillar width of a twin tunnel affects its stability. To ensure this end, global tunnel safety factors obtained numerically using shear strength reduction technique, local safety factors of a pillar using the equation that Matsuda et al. suggested, and strength/stress ratios of the pillar were estimated and their results were analyzed for two sections with different rock covers. For a reasonable design of a twin tunnel pillar, it was turned out that strength/stress ratio, the local pillar safety factor, and global tunnel safety factor should be used interrelatedly rather than independently.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.617-626
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• 2021

During supersonic flight of vehicles, the thermal behavior of structures under high-temperature environment is important for thermal-structural design. In this study, full-field thermal deformation and stress concentration of the notched structure was performed using global-local multi-digital image correlation (multi-DIC) systems. This techniques were developed and implemented by multi-DIC systems consists of 2D DIC system and 3D DIC system. The specimen was heated in a heating chamber to achieve the thermal expansion behavior. Then the images of structure's deformation and stress concentration at various temperature were recorded and analyzed by multi-DIC system. Afterward, full-field thermal deformation of the notched structure was determined with DIC technique and stress concentration at the notched structure was calculated by further processing. Finite element analysis of the notched structure is performed in ABAQUS^TM and the results of the experiments show good agreement with those obtained from simulation. The results achieved in this study show the efficiency of the muilti-DIC method in thermal deformation as well as stress concentration of notched structure.

• Journal of Korean Home Economics Education Association
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• v.32 no.3
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• pp.111-133
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• 2020

The purpose of this study is to analyze the contents of global citizenship education in the 2015 revision of Home Economics textbook and examine the relevance of global citizenship education in the subject of Home Economics. To this end, the contents of global citizenship education included in the 2015 revision of middle school Home Economics textbook were extracted and analyzed from the viewpoint of the UNESCO Topics and Learning Objectives (TLO), according to the procedure of the concurrent triangulation design. When the frequencies of inclusion of the 9 topics of TLOs were counted, about 54.6% of global citizenship education(GCED) content covered in the 2015 revision of Home Economics textbooks in total was related to the socio-emotional aspects. In particular, TLO 4 (Different levels of identity) showed the highest ratio, followed by TLO 5(Different communities people belong to and how these are connected) and TLO 1 (Local, national and global systems and structures). As a result of categorizing global citizenship education learning topics extracted from Home Economics textbooks of middle school by Home Economics sub-topic area, the child and family(94) area showed the greatest relevance to all learning topics. Food and nutrition(13), clothing(13), housing(15), and consumption (14) showed similar distributions of learning subjects. Child and family area is related to global citizenship education in the topics of adolescent development and its characteristics, family relations, sexual and domestic violences prevention, change in family structures and healthy families, aging society and work-family balance, and life planning and career exploration. The food and nutrition area is related to global citizenship education in the topics of nutrition and eating behavior, and adolescents' food selection and safe cooking. The topic of clothing management and recycling of clothing area, housing culture, residential space utilization, and residential life and safety of housing area, consumer life in adolescence of consumption area were related to the learning subject of global citizenship education. As such, high relations between GCED learning topics and Home Economics learning content elements were found. It is expected that the data of this study will be used as basic data for program development, class improvement, and textbook development with global citizenship education as a content element in Home Economics education.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.47-57
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• 2013

This study aims at analyzing transportation equity between geographical areas of Gyonggi Province, by taking both the transportation infrastructure and travel behavior into account. Indicators of transportation infrastructure include the indices of road infrastructure, transit infrastructure and regional characteristics. Travel behavior concerns information from bus card data on a survey day. The hot-spot analysis conducted included spatial cluster analysis and global/local regression analyses. The analysis results identified geographical areas of four different classes of transportation equity, from the area with high level infrastructure surrounded by the areas with high level infrastructure (HH) to the area with low level surrounded by the areas with low level (LL). The area of HH type showed big numbers of passengers, trips and transfers, whereas the area of LL type shows big figures of internal trip frequency, travel time, travel distance, travel speed and transit fare. Global regression analysis showed that number of passengers, number of transfers, number of internal trips and mean travel speed are important to the level of transportation infrastructure. GWR with these four significant variables significantly improved the AICs and ANOVA results, which implies that the infrastructure is likely explained by travel characteristics differently between geographical areas in Gyonggi Province.

• Korean Journal of Child Studies
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• v.17 no.1
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• pp.189-212
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• 1996

The purpose of this study was to investigate how parental childrearing behavior and children's sibling relationships are related to children's self-esteem. 440 middle class families consisting of two children and their parents were the subjects of this study. The research instruments included a childrearing behavior questionnaire, the Sibling Relationships Questionnaire (Furman & Buhrmester, 1985), and the Self-Perception Profile for Children (Harter, 1985). Analyses of the data included correlation analysis, canonical correlation, regression, stepwise multiple regression, and MANOVA with stepwise discriminant analysis as the follow-up test. The most powerful predictors of children's self-esteem were the Warmth-Acceptance of childrearing behavior and the Warmth-Closeness of sibling relationships. The self-esteem dimension was best predicted by parental childrearing behavior and by children's sibling relationships was Global Self-Worth. Behavioral Conduct was best predicted by the Rejection-Restriction factor of childrearing, and by Conflict (for boys) and Rivalry (for girls) factors of sibling relationships. Children's self-esteem was related more strongly to the Warmth-Acceptance and the Rejection-Restriction of opposite-sex parents. The effects of Permissiveness-Nonintervention were stronger in same-sex parent-child dyads. Parental childrearing behaviors accounted for boy's self-esteem better than girl's with the exception of Behavioral Conduct. Sibling relationships accounted for girl's self-esteem better than boy's. The $2{\times}2$ MANOVA revealed interaction effects of parental childrearing behaviors and sibling relationships on children's self-esteem. Two factors of Rivalry and Conflict in sibling relationships and all three factors of childrearing behaviors showed significant interaction effects, The childrearing factor of Permissiveness-Nonintervention and the sibling factor of Rivalry, which were relatively weak predictors of self-esteem when acting alone, gained power in explaining children's self-esteem within the interactional context.

• The Korean Journal of Financial Management
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• v.20 no.2
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• pp.127-150
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• 2003

This study analyzes how capital market comovement can affect investors' decision making. We first analyze time-varying correlation coefficient between stock indices of U.S.A. and Korea. and then, using our empirical results, attempt to draw implications on investors' behavior. We find that the tendency of comovement between Korea and U.S.A. equity returns has considerably increased after the financial crisis of late 1997. Through the analysis of investors' behavior, we find that foreign investors, contrary to ITC's (Investment Trust Company) and individual investors, buy more shares in Korean markets as American stock prices go up. Foreign investors employ dynamic hedging strategy and give more weight on global economic factors than domestic ones. Our empirical results as a whole imply that investment behavior of foreign investors is most closely related to comovement of U.S.A. and Korea capital markets.

• Earthquakes and Structures
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• v.14 no.5
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• pp.411-424
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• 2018

This study explores the inelastic behavior of systems with flexible base. The use of a single degree of freedom system (ESDOF) with equivalent ductility to represent the response of flexible base systems is discussed. Two different equations to compute equivalent ductility are proposed, one which includes the contribution of rigid body components, and other based on the overstrength of the structure. In order to asses the accuracy of ESDOF approach with the proposed equations, the behavior of a 10-story regular building with reinforced concrete (RC) moment resisting frames is studied. Local and global ductility capacity and demands are used to study the modifications introduced by base flexibility. Three soil types are considered with shear wave velocities of 70, 100 and 250 m/s. Soil-foundation stiffness is included with a set of springs on the base (impedance functions). Capacity curves of the building are computed with pushover analysis. In addition, non linear time history analysis are used to asses the ductility demands. Results show that ductility capacity of the soil-structure system including rigid body components is reduced. Base flexibility does not modify neither yield and maximum base shear. Equivalent ductility estimated with the proposed equations is fits better the results of the numerical model than the one considering elastoplastic behavior. Modification of beams ductility demand due to base flexibility are not constant within the structure. Some elements experience reduced ductility demands while other elements experience increments when flexible base is considered. Soil structure interaction produces changes in the relation between yield strength reduction factor and structure ductility demand. These changes are dependent on the spectral shape and the period of the system with fixed and flexible base.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.151-160
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• 2017

Giving behavior can be defined to be a behavior intended to benefit the society's charity works and public works via sharing one's financial resources. The determinants of giving behavior largely consist of sociodemographic factors, such as the income, age, gender, religion, education level, residential areas, and tax deduction policy, etc. This paper considers the income level, self-esteem, and perceived responsibility toward social welfare, as the major research variables. Statistical results, based on 2014 Korean Welfare Panel data, show that the income level and self-esteem have positive influence on participation intention in charitable giving. However, welfare responsibility has negative impact on participation intention. Second, household income was the only salient, negative factor for giving efforts defined as the amount of donation over income, implying that the higher income brackets are giving less money relative to their income level, than those with lower income level. Contrary to our expectation, self-esteem and welfare responsibility were not statistically significant explanatory variables.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.269-276
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• 2020

Recently some researchers have challenged the truism by arguing that ethical leadership evokes followers' engagement in unethical behavior when that is benefit for organization(unethical pro-organizational behavior, called UPB). In this paper, I propose the relationships among the ethical leadership, affective commitment, and UPB based on social exchange theory and social identity theory. Using survey data from 10 companies 90 employees, the regressing analysis results indicate that there is positive and significant direct relationship between ethical leadership and UPB, and affective commitment paly as a partial mediator role among ethical leadership and UPB. Some implications, future research directions, and study limitations were discussed.

• Steel and Composite Structures
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• v.30 no.2
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• pp.81-96
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• 2019

The behavior of a new Three-Tube Buckling-Restrained Brace (TTBRB) with circumference pre-stress (${\sigma}_{{\theta},pre}$) in core tube are investigated through a verified finite element model. The TTBRB is composed of one core tube and two restraining tubes. The core tube is in the middle to provide the axial stiffness, to carry the axial load and to dissipate the earthquake energy. The two restraining tubes are at inside and outside of the core tube, respectively, to restrain the global and local buckling of the core tube. Based on the yield criteria of fringe fiber, a design method for restraining tubes is proposed. The applicability of the proposed design equations are verified by TTBRBs with different radius-thickness ratios, with different gap widths between core tube and restraining tubs, and with different levels of ${\sigma}_{{\theta},pre}$. The outer and inner tubes will restrain the deformation of the core tube in radius direction, which causes circumference stress (${\sigma}_{\theta}$) in the core tube. Together with the ${\sigma}_{{\theta},pre}$ in the core tube that is applied through interference fit of the three tubes, the yield strength of the core tube in the axial direction is improved from 160 MPa to 235 MPa. Effects of gap width between the core tube and restraining tubes, and ${\sigma}_{{\theta},pre}$ on hysteretic behavior of TTBRBs are presented. Analysis results showed that the gap width and the ${\sigma}_{{\theta},pre}$ can significantly affect the hysteretic behavior of a TTBRB.