• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.475-479
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• 2009

In ad hoc network, the scarce energy management of the mobile devices has become a critical issue in order to extend the network lifetime. Current research activity for the Minimum Energy Multicast (MEM) problem has been focused on devising efficient centralized greedy algorithms for static ad hoc networks. In this paper, we consider mobile ad hoc networks(MANETs) that could provide the reliable monitoring and control of a variety of environments for remote place. Mobility of MANET would require the topology change frequently compared with a static network. To improve the routing protocol in MANET, energy efficient routing protocol would be required as well as considering the mobility would be needed. In this paper, we propose a new method, the CACH(Context-aware Clustering Hierarchy) algorithm, a hybrid and clustering-based protocol that could analyze the link cost from a source node to a destination node. The proposed analysis could help in defining the optimum depth of hierarchy architecture CACH utilize. The proposed CACH could use localized condition to enable adaptation and robustness for dynamic network topology protocol and this provide that our hierarchy to be resilient. As a result, our simulation results would show that CACH could find energy efficient depth of hierarchy of a cluster.

• Journal of Agricultural Extension & Community Development
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• v.14 no.2
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• pp.373-394
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• 2007

The purposes of this study were to explore decision-making patterns of rural couples and to clarify the differences between socio-demographic variables related to the patterns. The data were gathered from 1,870 rural households through interviews with structured questionnaire in the 187 rural communities sampled by multi-staged cluster stratified sampling method in November 2005. A total of 1,106 farm households including householder and spouse participated in the interview. The results of this study were as follows: First, in general, mainly householder made decision-making in the areas of dealing with real estate and selling farm products, while spouse decided in the areas of choosing television channel and deciding living expenses. Second, there were no significant differences of patterns by age, education and income level. Third, decision-making patterns were significantly different by sex and family type. According to the results of the study, in farm household, 'pattern of mainly householder or husband decision-making' was high yet as regarding agricultural decision making. Therefore, researchers suggested that educational program could be helpful for rural couples to participate in practicing gender equity decision- making.

• Korean Journal of Childcare and Education
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• v.16 no.5
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• pp.105-126
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• 2020

Objective: This study aimed to reveal pre-service early childhood teachers' perception of children's environmental education using concept mapping and demonstrating its importance. Methods: Based on Kane and Trochim's(2007) procedure, 33 pre-service early childhood teachers conducted brainstorming and statement writing, and then the importance of selected statements were rated by 202 pre-service early childhood teachers. Selected statements were analyzed through multidimensional scaling and hierarchical cluster analysis. Results: Pre-service early childhood teachers perceived children's environmental education as concept mapping with 2-dimensions and eight clusters. The following eight clusters were established (1) daily practice through hands on experience, (2) nature environment, (3) recognizing and coping with environmental issues, (4) environmental preservation practices, (5) environmental sensitivity and consideration, (6) purpose of children's environmental education, (7) necessity for children's environmental education (8) Practice through connection with child's home and community. And then among the eight clusters, the most important was recognized as 'daily practice through hands on experience', and among the statements 'young children learn through the method of playing in nature and experience nature' was considered the most important. Conclusion/Implications: Based on these results, we discuss the importance of children's environmental education of pre-service early childhood teachers and how to support to develop teacher's training program.

• Journal of Korean Home Economics Education Association
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• v.13 no.3
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• pp.35-57
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• 2001

The purposes of this study were to investigate the current status on stating a summary of assessments in the practical arts education and to analyze the problem and find out the reformation strategy for them. To achieve these purposes. 180 teachers working in all elementary schools located in Daegu-city was selected by systematic cluster sampling method. The data were collected by using the mailed questionnaire developed by the researcher, and there was a response rate of 91.7%. Findings showed that it was not realized the valid and reliable stating a summary of assessments because it was not fixed throughly in the elementary school. So many teachers had difficulties in assessing the practical arts subject and stating a summary of assessments. They used the computer programs of CMI(Computer Management Instruction) . Black Box. SA(Stand Along) for stating a summary of assessments. It was recommended that valid and reliable criteria of stating a summary of assessments should provided, and on-the-job training on the developing and selecting a good tools for stating a summary of assessments should required. And. it was also required that the various codes of stating a summary of assessments should developed. and the various materials. equipments. and systems should provided for teachers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.995-998
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• 2003

This paper presents the deposition of poly-Si thin-film and fabrication of a solar cell by VHF-PECVD method. The poly-Si thin films. and pin-type solar cells are fabricated using multi-chamber cluster tool system. A 7.4% conversion efficiency was achieved from poly-Si thin film solar cells with total thickness less than $5{\mu}m$. The physical characteristic was measured by Raman spectroscopy, solar cell characteristic was measured under AM1.5 illumination.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.653-661
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• 2016

In this paper, we provide a suitable optimal exponent in the generalized Pythagorean theorem and propose to use the logistic model & the probit model to estimate the winning rate in Korean professional baseball league. Under a criterion of root-mean-square-error (RMSE), the efficiencies of the proposed models have been compared with those of the Pythagorean theorem. We use the team historic win-loss records of Korean professional baseball league from 1982 to the first half of 2015, and the proposed methods show slight outperformances over the generalized Pythagorean method under the criterion of RMSE.

• Journal of the Korean Data and Information Science Society
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• v.20 no.1
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• pp.57-64
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• 2009

In this paper, 30 main cities are clustered based on precipitation, temperature, wind speed, photo period, and humidity. We found that the resulting clusters has strong relationships with geographical locations. These results make sense because, although Korea is a small country, Korean weather is known to have strong locality. The largest number of clusters is found when wind speed is used as an interested variable for clustering and the smallest number of clusters is found when photo period is used. The large number of clusters based on wind speed indicates that wind speed is affected easily by local geography.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.293-300
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• 2018

To realize various opportunities to choose careers for adolescent sports players, first, it is necessary to help them choose a job suitable for each student's aptitude. In reality, adolescent sports players absolutely have insufficient time for choosing various careers unlike general adolescents and realizing them. Thus, differentiated and specialized convergence learning materials are needed by each job cluster suitable for adolescent sports players' aptitude. The learning materials, specialized for these individual job clusters are a method to show a great effect on education with investing the minimum time, so they have a high value for utilization as necessary learning information for the realization of various opportunities to choose various careers for adolescent sports players.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.3
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• pp.15-31
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• 2014

The purpose of this study was to investigate the effects of sociocultural attitudes toward appearance on male consumers' apparel buying behavior and appearance management behavior. The subjects were 353 males aged from 40 to 59 years old. The research method was a survey and the questionnaire consisted of sociocultural attitude toward appearance items, apparel buying behaviors items, appearance management behaviors items, and subjects' demographic characteristics items. The data were analyzed by Cronbach's ${\alpha}$, factor analysis, cluster analysis, multiple response analysis, ${\chi}2$ test, ANOVA and Duncan's multiple range test. The results were as follows. Three dimensions (appearance importance awareness, slimness importance awareness, internalization) were emerged on sociocultural attitude toward appearance, and subjects were divided into 4 groups(receptive, unreceptive, awareness, and internalized group) by this variable. The 4 groups by sociocultural attitude toward appearance showed many differences on apparel buying behaviors and appearance management behaviors. Receptive and internalized group more importantly regarded fashion trend and store display as apparel buying motives, design and trend as selection criteria, and did shopping to buy clothes more often than awareness and unreceptive group. Receptive and internalized group recognized higher the need for various appearance management behaviors and spent more expense to enhance their appearance than other groups.

• Journal of The Korean Association For Science Education
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• v.15 no.4
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• pp.404-416
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• 1995

The purpose of this study was to investigate the relationship of the cognitive levels and the science process skills based on the cognitive styles. The subjects of the study were 5-6th grade 790 students sampled by random cluster sampling method in three schools from large cities, small cities, and rural areas respectively. The results are as follows. 1) The field independent students showed significantly higher(p< 0.001) cognitive level than the field dependent ones. 2) The field independent group showed higher formation rate of subskills of the logical thinking skills than the field dependent groups. 3) It was found out that the field independent group attained significantly higher scores of science process skills than the field dependent group in 5th and 6th grade students. 4) The more cognitive levels became higher, the more science process skills were significantly higher(p< 0.001). 5) There were significant(p<0.001) differences among the science process skills for grade levels and three regions. And that there were not significant differences in the science process skills between males and females, 6) The science process skills of the field independent and the formal operational group could be acquired better scores in the science process skills than those who belong to another combinations.