• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.6
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• pp.28-39
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• 2010

The study aims at offering a solution to the problems of transmission delay and data throughput decrease as the number of contending On-Board Units (OBU) increases by applying CSMA medium access control protocol based upon IEEE 802.11p. In a competition-based medium, contention probability becomes high as OBU increases. In order to improve the performance of this medium access layer, the author proposes EDCA which a adaptive adjustment of the Contention Windows (CW) considering traffic density and data type. EDCA applies fixed values of Minimum Contention Window (CWmin) and Maximum Contention Window (CWmax) for each of four kinds of Access Categories (AC) for channel-specific service differentiation. EDCA does not guarantee the channel-specific features and network state whereas it guarantees inter-AC differentiation by classifying into traffic features. Thus it is not possible to actively respond to a contention caused by network congestion occurring in a short moment in channel. As a solution, CWminAS(CWmin Adaptation Scheme) and ACATICT(Adaptive Contention window Adjustment Technique based on Individual Class Traffic) are proposed as active CW control techniques. In previous researches, the contention probabilities for each value of AC were not examined or a single channel based AC value was considered. And the channel-specific demands of IEEE 802.11p and the corresponding contention probabilities were not reflected in the studies. The study considers the collision number of a previous service section and the current network congestion proposes a dynamic control technique ACCW(Adaptive Control of Contention windows in considering the WAVE situation) for CW of the next channel.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2835-2842
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• 2013

In this paper, service differentiation scheme using optical buffer that is reduced in size with slow-light technology in optical burst switching networks is presented. In suggested scheme, each outport has buffer to store high-class burst only in case that all its wavelengths are occupied. When all wavelengths are being used, a new arriving high-class burst goes into the buffer and waits until a burst is serviced. As soon as a burst is serviced with a wavelength, the high-class burst at buffer is allocated to the free wavelength. In case that low-class burst is arriving under the same situation, it is not stored at the buffer but discarded. An analytical model is derived to analyze the performance of the suggested scheme and compare its performance with the conventional scheme such as preemption and deflection as well as no service differentiations.

• Journal of Industrial Convergence
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• v.19 no.6
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• pp.59-66
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• 2021

Globally, the prolonged pandemic of COVID-19 (COVID-19) has had a great impact on all industries. In particular, in the field of education, online classes (non-face-to-face) had some negative perceptions of online classes, such as lack of preparation for learning and student dissatisfaction with the class. According to the current situation survey in 2020, non-face-to-face classes accounted for about 56% of the class, and streaming real-time classes and video content-based classes accounted for most of the class. This study empirically analyzes the problems to be solved by online classes through the 2020-2021 survey (software application practical class university students), and explains the detailed program and development plan (implementation result). This study intends to contribute to the development of online learning development of each educational institution after the end of the corona crisis.

• Education of Primary School Mathematics
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• v.12 no.2
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• pp.133-143
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• 2009

In this thesis, we conduct a comprehensive analysis of the current situation and the inherent problems found in modern statistics education in Elementary School. There are statistical curriculum, 7th textbook of elementary school level, practise of statistics class, connection of real life etc. Through analysis of these given problem, we explore the future direction of statistical education. Therefore, the statistical learning to make statistical situations and pose problems based on students' interests and students-related situations should be an effects on positive mathematical attitude and statistical thinking which could develop understanding statistical problems and thinking.

• Journal of The Korean Association of Information Education
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• v.20 no.3
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• pp.283-292
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• 2016

Based on revised 2015 curriculum, diversified SW education methods for elementary school students are researched, developed and applied. However, as most of SW education is based on English text, its coding process may be difficult for low graders of elementary school who are not familiar with English and Math. Under this situation, Kodu game lab based 'icon card board' by which coding could be learnt with ease through game and icon was developed and story activity, coding activity and collaboration activity (SCC) strategy based 17th session SW curriculum was applied and verified. As a result of research, in terms of satisfaction of students for SW class, students more than 86% recognized such class positively and a significant effect was obtained from students' interest level and learning model for coding.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.52-55
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• 2004

VMS (virtual manufacturing system) may be defined as a transparent interface/control mechanism to support human decision-making via simulation and monitoring of real operating situation through modeling of all activities in RMS (real manufacturing system). The three main layers in VMS are business process layer, manufacturing execution layer, and facility operation layer, and each layer is represented by a specific software system having its own input modeler module. The current version of these input modelers has been implemented based on its own 'local' framework, and as a result, there are no information sharing mechanism, nor a common user view among them. Proposed in this paper is a unified modeler framework covering the three VMS layers, in which the concept of PPR (product-process-resource) model is employed as a common semantics framework and a 2D graphic network model is used as a syntax framework. For this purpose, abstract class PPRObject and GraphicObject are defined and then a subclass is inherited from the abstract class for each application layer. This feature would make it easier to develop and maintain the individual software systems. For information sharing, XML is used as a common data format.

• The Research Journal of the Costume Culture
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• v.18 no.3
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• pp.550-558
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• 2010

Russian Constructivism, which took the lead in the Russian trend of art until the late 1920's, was influenced by European Cubism and Futurism. Breaking away from the previous realistic tendency, Russian Constructivism, to meet the ideology of the revolution, insisted the "Art into Street" and the "Art in Industry" with its abstract and geometric design. Russian Constructivism effected paintings of mid 1920's, as well as Industrial design and costume design. This operated remarkable changes in Russian form of costume and textile area. An unusual situation like revolution had provided the social justification to develop a new costume design not for the special class of people, but for the general public. In this atmosphere, the plan of clothing mass production began to progress. Although the Russian Constructivism costume of arts shows the similarity in the trend of fashion and the physical forms of those days, its fundamental idea in manufacturing costumes was 'to create costumes to be possible to mass-produce and to be wearable to anyone regardless of the social class'. Therefore, Constructivism costume of arts pursued dynamism and geometric form through non-objective design that has broken away from the handcrafted and traditional standards of the past. These distinct characteristics served as a momentum to seek costume design based on productivity and functionality.

• Research in Community and Public Health Nursing
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• v.18 no.1
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• pp.156-164
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• 2007

Purpose: This study was to investigate adequate strategies of PBL in community health nursing for learning in the real community situation. Method: Data were collected in a PBL class of 14 third-year students who solved problems and assessed PBL in community health nursing related to visiting nursing and chronic diseases. Results: The students guessed situations diversely, chose learning issues widely and mapped the learning concepts specifically. In the assessment of the presentation, the peers of the same group gave the highest score $29.00{\pm}3.36$, the tutor lowest score $22.83{\pm}5.15$. In 5-point Likerts scale, the group dynamic was highest ($4.18{\pm}.61$) and the presentation was lowest ($3.59{\pm}.84$). Conclusion: The group needs to include students who have experiences in the practice at the health centers. The PBL class should be managed by the block system along with the conventional learning. Students needs to practice the self-directed learning and the presentation in a first semester and then PBL. The introduction of community health nursing begins with the conventional lecture and the programs on life circle and health centers through PBL in the comprehensive curriculums.

• YAKHAK HOEJI
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• v.59 no.4
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• pp.190-200
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• 2015

Evaluation Project on Appropriate Prescribing (EPAP) which is analysing prescribing pattern and providing physicians feedback has begun in 2001. EPAP indicators are related to antibiotics for acute respiratory tract infections, overuse of injection, polypharmacy (no. of drugs prescribed together, no. of prescriptions with 6 or more drugs), prescribing of specific medication group (drugs for acid related disorders, NSAIDs, corticosteroids) and medication expenditure per prescription day. The aim of this study was to suggest a development plan for EPAP indicators suitable for domestic situation. A consensus group consisting of seventeen health care professionals evaluated significance of each therapeutic class for EPAP indicators expansion considering information such as magnitude of issue, prescribing indicators of foreign countries, reimbursement criteria by each therapeutic class. Based on the data and group survey, 5 classes were selected as candidates for prescribing indicators and we presented 24 indicators regarding 5 classes. The results suggested that we need to augment evaluation indicators of additional area.

• Hwankyungkyoyuk
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• v.20 no.3
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• pp.45-62
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• 2007

The purpose of this study was to analyze the status of environment-related teaching in elementary and secondary schools. A questionnaire survey was conducted for the study. Items in the questionnaire were developed based on the theory of environmental education and integrated education. The questionnaire was responded to 501 elementary school teachers, 273 middle school teachers, and 210 high school teachers in the city of Seoul and Kyunggi Province. The survey analysis revealed that elementary and secondary school teachers recognized 'environmental action skills' as the most important objective for school environmental education. Contrary to the teachers' expectations, it was found that there is insufficient teaching and learning materials for teaching in the domain of 'environmental action skills' and they could not confidently teach the skills in environment-related classes. For professional development of teachers in integrated environmental education, pre- and in-service programs will be developed systematically in a workshop to give teachers an opportunity to analyze teaching materials, design instruction plan, perform class trial, and evaluate the class situation for feedback. The results of this study can serve as a basic reference for improvement of environment-related subject education.