• Journal of Gifted/Talented Education
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• v.5 no.2
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• pp.139-156
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• 1995

The purpose of the study is to examine the effects of Gifted Education Isnstitute of Korea (GEIK) programs for gifted children especially in the areas of reasoning skills and creativity, thereby proving the effectiveness of the program. The subjects are 136 (103 boys and 33 girls) fourth, fifth, and sixth grade gifted children, who have participated in GEIK programs for more than six moths. They were stratified by the length of participation in GEIK programs. Ninety four children have participated for more than one year. Forty-two children have participated for less than one year. Both groups are rather homogeneous in IQ scores and school achievement levels at the time of enterance into GEIK programs. Both a Group Assessment of Logical Thinking (GAIT) and a Creativity test were used for the study on reasoning skills and creativity. GALT, developed by V. Roadranka, R. H. Yeany and M. J. Padilla in 1983, consists of 12 questions. It is classified into six subscales: conservation, proportional reasoning, controlling variables, provability reasoning, correlational reasoning, and combinatorial reasoning. The reliability of this test is .85. This test recommends to classify the stages of child development as follows according to the total test score. 0-4 point: Concrete Stage, 5-7 points: Transitional Stage, and 8 and above points: Formal stage. The Creativity Test was developed by Y. Lee and W. Chung (1971). It consists of four components: fluency, flexibility, originality, and openness. Only both fluency and openness were used in this study. In order to analyze data, T-Test, Intercorrelational Analyses, ANOVA, and Nultiple Regression were used. Followings are the results deduced from the above analoyses of the data. First, 43.48% of the subjects were on Concrete Stage, 36.78% were on the Transitional Stage, and 19.86% were on the Formal Stage in the developmental level classified by Piaget. Second, the students who have participated in GEIK programs more than one year acquired significantly higher score in GALT than the students who have participated in GEIK programs less than one year. Third, boys showed higher score in GALT than girls did. Fourth, there were statistically significant intercorrelations between six subscales of GALT. Fifth, the students who have participated in GEIK programs more than one year acquired significantly higher score in openness of creativity test than the students who have participated in GEIK programs less than one year. There were no significant differences in openness of creativity test between boys and girls. Sixth, the students who have participated in GEIK programs more than one year acquired significantly higher score in fluency of creativity test than the students who have participated in GEIK programs less than one year. Girls showed higher score in fluency of creativity test than boys did. Seventh, the students who acquired higher score in GALT showed higher score in both openness and fluency of creativity test. Followings are the conclusions deduced form the above results. First, the developmental level of reasoning skills of the fourth grade students participationg in GEIK programs is the same as that of 7th grade of normal Korean students and the same as those of 10th grade of U.S.A. and Philipoine students. Second, the GEIK programs are effective in improving reasoning skills. Third, the GEIK programs are effective in improving creativity. Fouth, reasoning skills and creativity can be improved by well planned programs. In conclusion, this study suggests that beyond reasoning skills and creativity, other areas such as areas in science skills, mathmatical skills, or verbal skills, etc., should be studied in the future.

• Journal of Korean Elementary Science Education
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• v.24 no.2
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• pp.145-159
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• 2005

Students' alternative concepts of evolution are similar to misconcepts and disputes which scientists had in science history. The aims of this study are to analyze the elementary children's concept in evolution based on science history. Lee (2004)'s two tests were applied to 6th grade to investigate the children's evolution concepts and genetic concepts related to the historical development of the evolution concepts. The test results were analyzed in accordance with 4 stages of science history based on Lee (2004)'s method. These stages are divided to stage 1 (Before Lamarck), stage 2 (Lamarck), stage 3 (Darwin), stage 4 (After Darwin). The major results are as follows. Most of elementary school children are fixed to the stage 2. They usually do not show the consistency of evolution concepts in the three dimensional aspects such as mechanism, time, and subjects. Many children do not have concrete meaning of gene, inheritance, sexual reproduction, mutation and could not connect these concetps and process of evolution. Also, they believe the inheritance of acquired traits and spontaneous generation. Therefore it is confirmed that they still have similar misconcepts and disputes which scientists had in transition time between stage 2 and 3 and most of children already have strong Lamarckian thought acquired from daily life experience before learning about natural selection and evolution.

• Structural Monitoring and Maintenance
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• v.9 no.1
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• pp.29-42
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• 2022

In mountainous areas of China, concrete poles with connectors are widely employed in power transmission due to its convenience of manufacture and transportation. The bearing capacity of the poles must have degenerated over time, and most of the steel connectors have been corroded. Carbon fiber reinforced polymer (CFRP) offers a durable, light-weight alternative in strengthening those poles that have served for many years. In this paper, the bearing capacity and failure mechanism of CFRP sheet strengthened existing reinforced concrete poles with corrosion steel connectors were investigated. Four poles were selected to conduct flexural capacity test. Two poles were strengthened by single-layer longitudinal CFRP sheet, one pole was strengthened by double-layer longitudinal CFRP sheets and the last specimen was not strengthened. Results indicate that the failure is mainly bond failure between concrete and the external CFRP sheet, and the specimens fail in a brittle pattern. The cross-sectional strains of specimens approximately follow the plane section assumption in the early stage of loading, but the strain in the tensile zone no longer conforms to this assumption when the load approaches the failure load. Also, bearing capacity and stiffness of the strengthened specimens are much larger than those without CFRP sheet. The bearing capacity, initial stiffness and elastic-plastic stiffness of specimen strengthened by double-layer CFRP are larger than those strengthened by single-layer CFRP. Weighting the cost-effective effect, it is more economical and reasonable to strengthen with single-layer CFRP sheet. The results can provide a reference to the same type of poles for strengthening design.

• Structural Engineering and Mechanics
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• v.88 no.5
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• pp.451-462
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• 2023

Lumped Damage Mechanics (LDM) is a theory proposed in the late eighties, which assumes that structural collapse may be analyzed as a two-phase phenomenon. In the first (pre-localization) stage, energy dissipation is a continuous process and it may be modelled by means of the classic versions of the theory of plasticity or Continuum Damage Mechanics (CDM). The second, post-localization, phase can be modelled assuming that energy dissipation is lumped in zones of zero volume: inelastic hinges, hinge lines or localization surfaces. This paper proposes a new LDM formulation for cracking in concrete structures in tension. It also describes its numerical implementation in conventional finite element programs. The results of three numerical simulations of experimental tests reported in the literature are presented. They correspond to plain and fiber-reinforced concrete specimens. A fourth simulation describes also the experimental results of a new test using the digital image correlation technique. These numerical simulations are also compared with the ones obtained using conventional Cohesive Fracture Mechanics (CFM). It is then shown that LDM conserves the advantages of both, CDM and CFM, while overcoming their drawbacks.

• Advances in concrete construction
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• v.4 no.3
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• pp.173-194
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• 2016

This paper consists in a study of a new contructive sequence of road viaducts with Movable Scaffolding System (MSS) using numerical tools based on finite element method (FEM). Traditional and new sequences are being used in Spain to build viaducts with MSS. The new sequence permits an easier construction of one span per week but implies some other issues related to the need of two prestressing stages per span. In order to improve the efficiency of the new sequence by reducing the number of prestressing stages per span, two solutions are suggested in this study. Results show that the best solution is to introduce the 100% of the prestressing force at the self-supporting core in order to improve the road viaduct construction with movable scaffolding system by reducing execution time without increasing economic costs.

• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.681-693
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• 2007

Construction techniques for continuous steel bridges were applied to steel-concrete double composite box girder bridges. Concrete depth and length at the bottom of the steel box in the negative moment region were determined by plastic moment region and negative moment region of the double composite section, respectively. Construction methods, such as crane lifting method, free cantilever method, and incremental launching method were used for the analysis of the construction stage. Two cases of the construction phase were considered and analyzed for the stress resultant of double composite girders. The behavior of the nose-deck elastic system was examined by three-dimensionless parameters, such as the nose length, the unit weight of the launching nose, and the flexural stiffness of the nose. The adoption of the launching nose has become an effective solution in the incremental launching of steel-concrete double composite box girder bridges.

• Journal of the Korean Geotechnical Society
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• v.34 no.12
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• pp.145-154
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• 2018

The damage investigation and inspection methods performed in concrete facilities such as bridges, tunnels, retaining walls and so on, are usually visually examined by the inspector using the surveying tool in the field. These methods highly depend on the subjectivity of the inspector, which may reduce the objectivity and reliability of the record. Therefore, the new image processing techniques are necessary in order to automatically detect the cracks and objectively analyze the characteristics of cracks. In this study, deep learning and image processing technique were developed to detect cracks and analyze characteristics in images for concrete facilities. Two-stage image processing pipeline was proposed to obtain crack segmentation and its characteristics. The performance of the method was tested using various crack images with a label and the results showed over 90% of accuracy on crack classification and segmentation. Finally, the crack characteristics (length and thickness) of the crack image pictured from the field were analyzed, and the performance of the developed technique was verified by comparing the actual measured values and errors.

• Steel and Composite Structures
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• v.17 no.4
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• pp.405-429
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• 2014

In this paper, it is aimed to determine the structural behavior of suspension bridges considering construction stages and different soil conditions. Bosporus Suspension Bridge connecting the Europe and Asia in Istanbul is selected as an example. Finite element model of the bridge is constituted using SAP2000 program considering existing drawings. Geometric nonlinearities are taken into consideration in the analysis using P-Delta large displacement criterion. The time dependent material strength of steel and concrete and geometric variations is included in the analysis. Time dependent material properties are considered as compressive strength, aging, shrinkage and creep for concrete, and relaxation for steel. To emphases the soil condition effect on the structural behavior of suspension bridges, each of hard, medium and soft soils are considered in the analysis. The structural behavior of the bridge at different construction stages and different soil conditions has been examined. Two different finite element analyses with and without construction stages are carried out and results are compared with each other. At the end of the analyses, variation of the displacement and internal forces such as bending moment, axial forces and shear forces for bridge deck and towers are given in detail. Also, displacement and stresses for bridge foundation are given with detail. It can be seen from the analyses that there are some differences between both analyses (with and without construction stages) and the results obtained from the construction stages are bigger. It can be stated that the analysis without construction stages cannot give the reliable solutions. In addition, soil condition have effect on the structural behavior of the bridge. So, it is thought that construction stage analysis using time dependent material properties, geometric nonlinearity and soil conditions effects should be considered in order to obtain more realistic structural behavior of suspension bridges.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.280-290
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• 1998

The two objectives of this study were 1) to develop an educational program based on the Self-Efficacy Theory(SET) of Bandura, and 2) to investigate the effects of the educational program on the management of menopause. The investigation process of this study was done in two phases. The first phase was to development an educational program through video tape. A telephone coaching program served as a follow-up to the educational video program and provided encouragement and support to the subjects. The second phase was the experimental stage. This experimentation was conducted to determine whether an educational program based on theory of Bandura would increase self-efficacy and management of menopause. Results : The developed video consisted of 2 parts. Part one discussed symtoms and management of menopause. Part two reflected the vicarious step-by-step success of middle-aged women's of menopause through the effective use of the 5 factors mentioned above. Telephone coaching program served as a followed to the educational video program and provided encouragement and support to the subjects. Total length of video is 32 minutes. Hypothesis stated in phase two were supported by the following result. Experimental group increased general-self-efficacy scores. Experimental group increased concrete-self-efficacy scores. Experimental group increased objective and subjective management of menopause scale.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.328-334
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• 2003

Evaluating stability of dam foundations is one of the prime areas of any rock engineering investigations. Despite best engineering efforts in the design and construction of dam foundations, the foundation regime of a constructed dam suffers deterioration due to continuous erosion from backwater current of dam discharge and dynamic effects of loading and unloading process. Even during construction, development of frequent cracks due to sudden thermal cooling of concrete blocks is not uncommon. This paper presents two case studies from India and Bhutan. In the first case, the back current of water discharge from the Srisailam dam in India had continuously eroded the apron and has eaten into the dam foundation. In the second case with dam construction at Tala Hydroelectric Project in Bhutan, sudden overflow of river during the construction stage of dam had led to development of three major cracks across the dam blocks. This was ascribed to adiabatic cooling effect of concrete blocks overlain by chilled water flow. Non-destructive evaluation of rock mass condition in the defect regime by the borehole GPR survey helped in arriving at the crux so as to formulate appropriate restoration plan.