• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.8
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• pp.1810-1821
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• 1995

Photoelastic experiment has been used to analyze stress of structure and stress in the vicinity of crack tip etc.. Model experiment such as photoelastic experiment has been restricted by problem of residual stress in the photoelastic model material. They are generated by molding, cutting and time effects etc.. They produce some errors in the results of photoelastic experiment data. In this paper, stress optic law considering residual stress already developed by authors was applied to the stress concentration problem and fracture mechanics. Although the specimen was bad with residual stress, we could obtain good results by using the stress optic law considering residual stress. It was found that the stress optic law of photoelastic experiment could be applied to the stress analysis of bimaterial.

• Steel and Composite Structures
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• v.4 no.3
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• pp.169-188
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• 2004

A mechanics model is developed in this paper for concrete-filled steel CHS (circular hollow section) beam-columns. A unified theory is described where a confinement factor (${\xi}$) is introduced to describe the composite action between the steel tube and the filled concrete. The predicted load versus deformation relationship is in good agreement with test results. The theoretical model was used to investigate the influence of important parameters that determine the ultimate strength of concrete-filled steel CHS beam-columns. The parametric and experimental studies provide information for the development of formulas for the calculation of the ultimate strength of the composite beam-columns. Comparisons are made with predicted beam-columns strengths using the existing codes, such as LRFD-AISC-1999, AIJ-1997, BS5400-1979 and EC4-1994.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.71-76
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• 2003

The purpose of this study is the development, application and assessment of probability and artificial neural network methods for assessing landslide susceptibility in a chosen study area. As the basic analysis tool, a Geographic Information System (GIS) was used for spatial data management. A probability method was used for calculating the rating of the relative importance of each factor class to landslide occurrence, For calculating the weight of the relative importance of each factor to landslide occurrence, an artificial neural network method was developed. Using these methods, the landslide susceptibility index was calculated using the rating and weight, and a landslide susceptibility map was produced using the index. The results of the landslide susceptibility analysis, with and without weights, were confirmed from comparison with the landslide location data. The comparison result with weighting was better than the results without weighting. The calculated weight and rating can be used to landslide susceptibility mapping.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.9
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• pp.700-706
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• 2003

This paper presents a 3D last design system that provides the 3-dimensional last data based on the FFD(Free Form Deformation) method. The proposed system utilizes the control points for deformation factor to convert from the 3D point cloud foot data to the 3D point cloud last data. The deformation factor of the FFD is obtained from the conventional last design technique, and constructed on the FFD lattice based on the bottom view and lateral view of the measured 3D point cloud foot data. In addition, the control points of FFD lattice is decided on the anatomical points of foot. The deformed 3D last obtained from the proposed FFD is saved as a 3D dxf foot data. The experimental results demonstrate that the proposed system have the descent 3D last data based on the openGL window.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.749-756
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• 2006

Because of the orthotropic elastic properties and significant two-way bending action, orthotropic plate theory may be suitable for describing the behavior of concrete filled grid bridge decks. Current AASHTO LRFD Bridge Design Specification(2004) has live load moment equations considering flexural rigidity ratio between longitudinal and transverse direction, but the Korea highway bridge design specification(2005) doesn't. The Korea highway bridge standard specification LRFD(1996) considers an orthotropic plate model with a single load to estimate live load moments in concrete filled grid bridge decks, which may not be conservative. This paper presents live load moment equations for truck and passenger car, based on orthotropic plate theory. The equations of truck model use multiple presence factor, impact factor, design truck and design tandem of the Korea highway bridge standard specification LRFD(1996). The estimated moments are verified through finite-element analyses.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.308-315
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• 2002

Fragility analysis is widely used for the seismic safety evaluation of a structure. In fragility analysis, damage evaluation is a crucial factor. Most of the present fragility analyses use the representative responses such as displacement and absorbed hysteretic energy as a tool of damage evaluation. But damage evaluation method that can represent the local damage of a structure is required in the case of piers of which the local damage can cause the whole failure of bridge system. Therefore this study proposes a damage index, which can represent the distribution and magnitude of local damage by using the Lee and Fenves'plastic-damage model. Using the proposed damage index, fragility curves and damage probability matrix of pier are produced and fragility analysis is performed.

• Hwankyungkyoyuk
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• v.22 no.4
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• pp.40-52
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• 2009

The purpose of this study was to validate New Ecological Paradigm(NEP) Scale for use with elementary school students in Korea, and to obtain evidences of validation for interpreting the scores on the instrument. Three pilot tests were taken to modify and 1,003 fifth and sixth grade students in elementary schools participated in this survey. To examine the reliability and validity of the NEP Scale for elementary school students in Korea, item analysis(mena, skewness, kurtosis, item-total correlation), internal consistency estimate, exploratory factor analysis, confirmatory factor analysis, and t-test were used. After analyzing their results, the authors suggest that a 2-dimensional(pro-NEP, anti-NEP) modified NEP Scale, with 15 items and revised wording, is appropriate for use with elementary school students in Korea.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.75-75
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• 2003

Silica has been known to be a factor in acute cell injury and chronic pulmonary fibrosis. In Rat2 fibroblasts, silica induced the activation of NFkB, which plays a crucial role in regulating the expression of many genes involved in the subsequent inflammatory response. In addition, we observed that TAK1 and NIK were involved in silica-mediated NF-kB activation in Rat2 cells. (omitted)

• Korean Journal of Child Studies
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• v.23 no.1
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• pp.139-151
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• 2002

This study compared generative fathering and parenting styles of 90 Korean and 73 American fathers who had a child 3 to 5 years of age. The data were collected through questionnaires on generative fathering, parenting styles, and father-child relationships. Results showed that Korean fathers were more involved in child rearing and perceived their parental responsibilities more strongly than American fathers; American fathers showed authoritative parenting and Korean fathers showed authoritarian parenting styles; among American fathers, the warmth factor contributed to the closeness between father and child; among Korean fathers, the control factor showed a negative relationship with conflict between father and child. These results suggest that the function of father's control in child development might vary by cultural contexts.

• Korean Journal of Child Studies
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• v.15 no.2
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• pp.69-96
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• 1994

The purpose of this study was to develop an inventory for measuring verbal control modes of korean parent. The subjects of this study were 332 children of fifth and sixth grade in elementary schools located in Seoul. Forty seven questions were developed, of which 24 were collected from other previous studies and 23 were newly developed by the researcher and each question was composed of 3 items. The 141 items (47 questions x 3 items) were analyzed by the statistical methods of item analysis, principal factor analysis. The resulting inventories composed of 28 (84 items) and 29 (87 items) questions assess the three types of verbal control modes of both mothers and fathers: imperative control, position-oriented control and person-oriented control. Internal consistency of the scale was high (Cronbach's= .91-.95). Factor validity was also satisfactory (.66-.87).