• School Mathematics
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• v.16 no.3
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• pp.613-631
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• 2014

The aim of this study was to investigate how the small group activity system influences individual to form concepts of prime number and composite number through activity theory on learning process of mathematically gifted 5th-grade students. Student's worksheets, recorded video, and interview were gathered and transcribed for analyzing data. Process of concept formation and using symbol behavior were used to derive the stage of mathematical concept from students, and the activity system and stage of concept formation process were schematized through analysis of whole class activity system and small group activity system based on activity theory. According to the results of this study, two students who were in different activity groups separated into the state of semi-concept and the stage of complex thinking respectively, and therefore, social context and the activity system had effects on process of concept formation among the students.

• The Mathematical Education
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• v.50 no.3
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• pp.285-308
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• 2011

The objective of this study is to review how researches on mathematics education are being conducted currently in Korea and overseas and to examine the current state of domestic researches on mathematics education from a broader view. Although many efforts have been made to understand trends in researches on mathematics education, there have been few in depth studies on research trends in overseas or for comparison between domestic and overseas trends. Thus, this study classified and analyzed 181 domestic articles between 2005 and 2009 in the journals and and 201 overseas articles in the journals and according to year, research area, research contents, school level, research method, and key words using the PME classification system with some modification. Through these analysis, we examined research trends on secondary mathematics education in Korea and overseas. The research findings are as follows. First, 'teaching learning process' was a spotlight area both at home and overseas, and 'realistic mathematics' and 'social cultural subjects' were not covered much either at home or overseas. 'Mathematical communication' occupied a very small portion in Korea but was a highly interesting area in overseas research. Second, research contents of interest were different between Korea and overseas. Research on general area was the mainstream. But geometry and statistics were mainly studied in Korea and algebra and analysis in overseas. Third, research related to middle school was twice more than that related to high school in Korea, But, research related to middle school was the same as high school in overseas. Fourth, qualitative research was the absolute majority both at home and overseas, and philosophical didactical analysis was used only in Korea. Fifth, the order of key words were problem solving - teacher - curriculum - creativity - textbook in Korea, but teacher - teaching - semiotic - affective factor - proo f- problem solving - technology in overseas.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.159-175
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• 2011

The purposes of this study are to evaluate the navigability of three web-based mapping applications and to suggest how to improve the navigability of all web-based mapping applications. With these purposes, this study conducted a web-based survey congruent with a think aloud and systematic observation for individual participants, followed up by a focus group with all participants. Based on the findings, recommendations are proposed for web-based mapping applications that include a standard click and drag panning function in mapping applications, a scaled zooming option, increased text for icons and buttons, and other potential changes to computer hardware for increased navigability in these applications. By improving the navigability of web-based mapping applications, the learning time may be reduced for each application and the speed at which users' geographic information needs are met will be quicker.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.22-33
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• 2005

In this paper, an efficient signal interference control technique to improve the high convergence speed of LMS algorithms is introduced in the adaptive transversal filter of DS/SS. The convergence characteristics of the proposed algorithm, whose coefficients are multiply adapted in a symbol time period by recycling the received data, is analyzed to prove theoretically the improvement of high convergence speed. According as the step-size parameter ${\mu}$ is increased, the rate of convergence of the algorithm is controlled. Also, an increase in the stop-size parameter ${\mu}$ has the effect of reducing the variation in the experimentally computed learning curve. Increasing the eigenvalue spread has the effect of controlling which is downed the rate of convergence of the adaptive equalizer. Increasing the steady-state value of the average squared error, proposed algorithm also demonstrate the superiority of signal interference control to the filter algorithm increasing convergence speed by (B+1) times due to the data-recycling LMS technique.

• Journal of Korea Multimedia Society
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• v.11 no.3
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• pp.301-314
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• 2008

The existing event recognition is accomplished with the limited systematic foundation, and thus much longer learning time is needed for emergency scenario interpretation due to large scale of probability data. In this paper, we propose a method for nile-based event recognition of an independent object(human) which extract a feature vectors from the object and analyze the behavior pattern of each object and interpretation of emergency scenarios using a probability and object's events. The event rule of an independent object is composed of the Primary-event, Move-event, Interaction-event, and 'FALL DOWN' event and is defined through feature vectors of the object and the segmented motion orientated vector (SMOV) in which the dynamic Bayesian network is applied. The emergency scenario is analyzed using current state of an event and its post probability. In this paper, we define diversified events compared to that of pre-existing method and thus make it easy to expand by increasing independence of each events. Accordingly, semantics information, which is impossible to be gained through an.

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.139-159
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• 2012

The purpose of this research is to increase understanding about 'an attitude' and to develop the contents of the reading attitude survey questionnaire through the analysis and comparison of reading attitude models. An attitude has an individual's perception and feeling about events, problems, people or things, and it also includes the state prepared for reaction. An attitude consists of emotion, cognition and behavior and it is formed by experience, learning or value judgment. Reading attitudes are composed of cognitive factors that represent beliefs or opinions about reading, emotional factors that represent evaluation and emotion about reading, and behavioral factors that represent intentions or behavior to reading. The analysis of the components of the reading attitude models shows the fact that the influencing factors of reading attitude formation are the reading experience, beliefs of reading results, beliefs about others' expectations and reading environments. Thus, the contents of reading attitude survey questionnaires should include such contents as reading experience, beliefs of reading results, beliefs about others' expectations, and reading environments.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1788-1799
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• 2006

Assessment of the implementation of a web-based courseware technology application across a merchandising program over a two-year period provides empirical evidence that students believe the technology was easy to use and useful. Results also show that the use of the application was not a hard-ship for the students in terms of time or access, that students in lower class ranks who had not had technology enhanced courses previously were more satisfied with the technology than upper class students, and that perceptions of the technology and satisfaction with it increase with experience using the technology.

• Journal of the Korean Society of Earth Science Education
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• v.4 no.1
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• pp.57-65
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• 2011

The purposes of this study investigated the effects of placement of analogy on the conceptual changes of air of elementary students, while learning the air conceptions. The subjects consisted of 108 students who are in the sixth grade classes in an elementary school in Busan city. For this study, comparative group(37 members), experimental group I(37 members), and experimental group II(34 memgers) were selected. A pre-test and a post-test on the air conception were done both for the comparative group and the experimental groups. The results are as follows. First, the averages of experiment group I and II are statistically higher than comparative group's. By the way, it just has a small gap between the comparative group and the experimental II. In other words, activity of analogy does not keep always constant to change of air conceptions of elementary students. Therefore, it has a different reason that only before or after during the analogy. Second, it shows that experimental group I has effected on a more change of air conceptions as compared with experimental group II. Then, the first group's result shows better than the other group's result. From this result, six grade students showed a change of air conceptions very well by analogy. It means if the analogy is given to students at the beginning state of chapter, they can understand scientific concepts easily.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.549-567
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• 2015

A first-order moment method (FORM) reliability analysis is commonly used for structural stability analysis. It requires the values and partial derivatives of the performance to function with respect to the random variables for the design. These calculations can be cumbersome when the performance functions are implicit. A Gaussian process (GP)-based response surface is adopted in this study to approximate the limit state function. By using a trained GP model, a large number of values and partial derivatives of the performance functions can be obtained for conventional reliability analysis with a FORM, thereby reducing the number of stability analysis calculations. This dynamic renewed knowledge source can provide great assistance in improving the predictive capacity of GP during the iterative process, particularly from the view of machine learning. An iterative algorithm is therefore proposed to improve the precision of GP approximation around the design point by constantly adding new design points to the initial training set. Examples are provided to illustrate the GP-based response surface for both structural and non-structural reliability analyses. The results show that the proposed approach is applicable to structural reliability analyses that involve implicit performance functions and structural response evaluations that entail time-consuming finite element analyses.

• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.261-287
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• 2005

The purpose of this paper is to explore the ways to improve the performance of SVM (Support Vector Machines) text classifier using inter-document similarities. SVMs are powerful machine learning systems, which are considered as the state-of-the-art technique for automatic document classification. In this paper text categorization via SVMs approach based on feature representation with document vectors is suggested. In this approach, document vectors instead of index terms are used as features, and vector similarities instead of term weights are used as feature values. Experiments show that SVM classifier with document vector features can improve the document classification performance. For the sake of run-time efficiency, two methods are developed: One is to select document vector features, and the other is to use category centroid vector features instead. Experiments on these two methods show that we can get improved performance with small vector feature set than the performance of conventional methods with index term features.