• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.287-307
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• 2011

The purpose of this study is to investigate levels of mathematically gifted students' understanding of statistical samples through comparison with non-gifted students. For this purpose, rubric for understanding of samples was developed based on the students' responses to tasks: no recognition of a part of population (level 0), consideration of samples as subsets of population (level 1), consideration of samples as a quasi-proportional, small-scale version of population (level 2), recognition of the importance of unbiased samples (level 3), and recognition of the effect of random sampling (level 4). Based on the rubric, levels of each student's understanding of samples were identified. t tests were conducted to test for statistically significant differences between mathematically gifted students and non-gifted students. For both of elementary and middle school graders, the t tests show that there is a statistically significant difference between mathematically gifted students and non-gifted students. Table of frequencies of each level, however, shows that levels of mathematically gifted students' understanding of samples were not distributed at the high levels but were overlapped with levels of non-gifted students' understanding of samples.

• Convergence Security Journal
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• v.13 no.2
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• pp.3-13
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• 2013

School violence that have occurred recently, showing a tendency to collectivization and diverse types of violence, as well as the quality and increase the damage levels. School violence in the home, school, and social factors, but is caused by the lack of awareness about the violence and the reporting of consciousness due to poor acts of violence indirectly assisted. The only place violence has caused the school to establish the legal and institutional arrangements in order to minimize school violence have no choice but to limit its effectiveness is negligible. The problem of school violence in connection with the problem of juvenile crime prevention and control, and punishment should be made of the complex and layered. Operation and School police system, School safety keeper system, school sheriff system since 2005, each municipality in order to minimize school violence, but have no practical help to limit the visible and symbolic effects. Nonexistent professional staff of the institution or school safety monitors emphasis on monitoring the physical state of the system in the form of 'guards' departure inherently have limitations. Also, to prevent criminal acts or violence in the state is not given special privileges and the appropriate role for the school keeper is a problem with the system. Report no other role can not be expected. Should therefore be preceded by a systematic improvement and training of experts in order to prevent school violence, and home and school, in terms of social support and measures.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.161-172
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• 2007

By prosperous condition of construction economy in the early 90s in Korea, the government needed a lot of the qualified professional engineers (PE) to manage the construction site. In order to meet the high demand of P.E., Government has established the admitted engineer systems(AES) in 1995 that give the authority of principal engineers to the admitted engineers who do not take the written examination but have equivalent working experience. Since 2000, professional $engineer^{\circ}{\phi}s$ shortage has been resolved. however, the opposite situation, which is serious over-supply of construction engineers has occurred. Thus, Government announced that would abolish the admitted engineer systems as recognized the existent admitted engineers(about 1,000,000 persons) from 2007. However, Professional Engineers Institution has strongly insisted that Government should not recognize existent admitted engineers. From this point of view, it is critical to make the supply-demand forecast systems as a derivative approach of System Dynamics also, that is useful in comparing the argument between Government and Professional Engineers Institution. This paper describes about principal $engineer^{\circ}{\phi}s$ supply change by admitted engineer system abrogation and suggests the idea to regulate the supply and demand with the improvement of the regal system.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.45-56
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• 2006

Recently, the more potential waste sites are being required as increasing the demand of better human life. But the construction of waste disposals has many restrictions because of lack of good quality clay and high cost of liners. So, in this study, we studied the liner materials to develop more cheaper soil liner that can be satisfied the environmental criterion for the coefficient of permeability and shear strength. A series of compaction test and triaxial (consolidation, permeability, and shear) tests were performed to obtain the optimized weight ratio of Bentonite-Soil mixture (B/S) including the least amount of bentonite. A series of soil tests were performed to acquire the appropriate weathered granite soil-bentonite mixture that is satisfied the environmental criterion of soil liner($k=1{\times}10^{-7}cm/sec$). At first, weathered granite soils were classified with four different particle-size soils, and B/S ratio was increased as 5% step for each particle-size. The test results showed that in case of weathered granite soil passing through No. 100 sieve, B/S=15% satisfied the soil liner criterion. The measured coefficient of permeability and the Chapuis's two equations were also compared. And a predicting equation for the coefficient of permeability was suggested, which is suitable for the mixture soil with the B/S ratio used in this study. The optimal weight ratio for the mixture soils used in this study was 15% in the both cases of permeability and shear strength.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.466-477
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• 2002

It was proposed that proper problem solving practice should improve students' questioning in physics. In the previous researches, improvement in students' questioning was observed after practice of making questions given the examples of desirable questions. In this study, the problem solving strategies used by experts were introduced to students in the form of step-by-step guide to follow in problem solving practice. The directions in the guide were concrete and operational for students to understand the expected behaviors explicitly. It was assumed that students could pinpoint the difficulty specifically through this guide, which would result in positive effects on students' recognition and expression of their own questions. The subjects in this study were college freshmen enrolled in the introductory physics for science or engineering major. The physics problems from the textbook were solved and practiced in the traditional way for controlled group. Worksheets designed to follow experts' problem solving strategies were used for the experimental group. Two groups were taught in the same way during lecture part of the class. Students were asked to describe the difficulties they had during homeworks or tests. Questions in this study means these descriptions written by students although they were not necessarily in the form of interrogative sentences. The questions were analyzed both in quantity and quality. Quantitatively, more students spontaneously turned in their questions in the experimental group than in the controlled group. Regarding the quality, there were more students in the experimental group than in the controlled group who described their difficulties in detail or recognized the need for the procedural knowledge.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.681-691
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• 2016

In this study, we investigated pre-service secondary chemistry teachers' use of teacher's guide in planning lessons. Eleven pre-service teachers at a college of education in Seoul participated in this study. Textbooks and teacher's guide books including various teaching materials were provided. Pre-service teachers used teacher's guide while they planned two lessons, which were a lecture and an instruction using science teaching model. A semi-structured interview was conducted. All of the teaching-learning materials and interviews were analyzed. The analyses of the results revealed that most pre-service teachers followed each lesson presented in teacher's guide, but they did not consider the structure of the whole unit and science curriculum. There were some cases that the exemplary lesson planning in teacher's guide helped them to select science teaching model. They modified the questions of textbook activity in planning their lecture. On the other hand, they modified the activity to fit each stage of the model in planning their instruction using science teaching models. Most pre-service teachers constructed their own worksheets by applying the materials of the teacher's guide. They recognized the components of assessment by considering exemplary lesson planning from the teacher's guide, and created questions by modifying the content of textbooks and teacher's guide books including various teaching materials. However, the questions which they made were limited in context of knowledge. They evaluated that introductory questions were not of interest to students, and modified or added new materials. Educational implications of these findings are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.768-779
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• 2017

Recently, the great number of mobile devices causes excessive data/control traffic problems in the centralized LTE/EPC network and such dramatically increased traffic is emerging as a critical issue. In the Centralized Mobility Management (CMM) based LTE/EPC network, the Packet Data Network Gateway (P-GW) plays the centralized mobility anchor role and it accommodates most of data traffic. To solve this problem, the IETF has proposed the Distributed Mobility Management (DMM) scheme, but it has only focused on the data traffic load balancing and could not solve the control traffic overload problem. In this paper, therefore, we propose a new SDN based hybrid CMM/DMM Mobility Management (C-DMM) architecture based on Packet Network Edge Gateway (P-EGW), and introduce a selection scheme between CMM and DMM according to a device's mobility and the number of PDN connections. In order to prove the efficiency of the proposed architecture and scheme, we compare the data traffic processing load and the control traffic processing load over each scheme by emulating them in the ONOS controller and the Mininet environment.

• Korean journal of communication and information
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• v.56
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• pp.237-256
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• 2011

The goal of this study is to examine consumers' cognition for the corporate social responsibility(CSR) and opinion to practical use of CSR on advertising (ex. corporate PR) in situation that CSR is treated with long-term and continuous activity in strategic marketing. The results of survey in this study are, first, the best effective method of CSR to introduce is TV or radio program placed first, internet came second, and followed by advertising. But the cognition process of CSR is internet palaced first in frequency. Thus it is very important to use of new media as a internet with regard to CSR. Second, respondents have thought positively about CSR and to practical use of CSR on advertising. But respondents answered that CSR is not enough though it's importance. Therefore marketers of companies is needed to transfer direction of CSR accord with consumers' liking and taste. Third, consumers have recognized that CSR in connection with characteristics core business of the companies. It is, image of company is not detached with CSR, more effective that CSR reflected characteristics of the company. Fourth, consumers have thought to active for CSR that the companies they like. Finally, these results are showed that is important brand management and corporate image management in strategic and macroscopic level include CSR.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.718-742
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• 2014

The capitalist economic process of glocalization and development of transportation and communication technology have led us to the significance of network city as well as concepts of global city, megacity region, etc. Network city theory pursues development of both individual cities and of the region of those cities through strengthening of mutual connectivity among them with specialized industries. On the basis of network city theory, this paper is to analyze specialized industries of cities and connectivity among them in the Youngnam region in S. Korea. It uses the methods of locational quotient, locational Gini coefficient, and shift-share method to analyze specialized industries of cities, and correspondence analysis, global and local Moran's I to examine connectivity among cities. As results, it can be identified that each city in the Youngnam region has its own specialized industries different from each others, but it seems not easy to grasp the overall extent of connectivity among them, partly because of the limitations of applied analysis methods and partly because of a lack of connectivity among cities themselves.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.50-55
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• 2009

To understand the status of the migrating Oriental Honey Buzzard(Pernis ptilorhynchus) in Korea, we carried out a preliminary study on the number and local movements of the Honey Buzzard from September 2005 to October 2007 at Hongdo Island, Jeonnam Province, Korea. A total of 702 Honey Buzzards in 2005, 404 individuals in 2006, and 659 individuals in 2007 were recorded during the fall migration season, but during the spring migration season only two and eight birds were observed in 2006 and 2007 respectively. The migrating Honey Buzzard showed peak numbers from 20 September to 5 October at the study site. According to observation of arrival time of538 Honey Buzzard in October 2007, a total of 2l6 birds(40.l %) were passing over Hongdo Island between 7:00 AM to 8:00 AM, rising skyward on columns of warm air. This suggests the use of thermal currents and avoidance of nocturnal movement for crossing water. They preferred moderate winds(<5 m/s in speed) from northwest, but the migrating number apparently decreased in case of strong winds (${\geqq}5 m/s$). This suggests that wind speed and direction are important environmental factors for migration of the Oriental Honey Buzzard. At present, it is unclear which breeding population(from north-eastern China or Japan) passes over Hongdo Island. Moreover, it is difficult to prove migration route and to understand migratory behaviors of the Oriental Honey Buzzard in Korea. To prove the breeding sites and routes of the migrants over the study site, we need more detailed and further studies such as satellite tracking researches.