• Journal of information and communication convergence engineering
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• 제9권3호
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• pp.295-300
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• 2011

Twitter is a popular microblogging service that enables the users to send and read short text messages. These messages are becoming source to analyze topic trends and identify relations among temporal topics. In this paper, we propose a method to classify the temporal topics on Twitter as a problem of grouping the similar patterns. To provide a starting point for a classification under the same topics, we identify the content word weighting scheme based on Latent Dirichlet Allocation (LDA). And we formulate how the temporal topics in the time window can be classified like peaky topics, constant topics, and periodic topics. We provide different real case studies which show the validity of the proposed method. Evaluations show that the proposed method is useful as a classifying model in the analysis of the temporal topics.

• 대한수학회지
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• 제46권6호
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• pp.1255-1265
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• 2009

We show that the Riemannian geometry of a tangent sphere bundle of a Riemannian manifold (M, g) of constant radius $\gamma$ reduces essentially to the one of unit tangent sphere bundle of a Riemannian manifold equipped with the respective induced Sasaki metrics. Further, we provide some applications of this theorem on the $\eta$-Einstein tangent sphere bundles and certain related topics to the tangent sphere bundles.

• East Asian mathematical journal
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• 제25권3호
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• pp.229-245
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• 2009

G. Cantor gave a deep influence to the society of mathematics in many ways, especially in the set theory. It is important for gifted and talented high school students in mathematics to understand the Euler constant and the fractal dimension of the Cantor set in a heuristic sense. On the historic basis of mathematics and the standard of high school students, we give the teaching method for the talented high school student to understand them better. Further we introduce the Riesz-N$\acute{a}$gy-Tak$\acute{a}$cs distribution and its first moment. We hope that from these topics, the gifted and talented students in mathematics will have insight in the analysis of mathematics.

• 한국과학교육학회지
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• 제8권1호
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• pp.73-79
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• 1988

According to the previous studies, the science education departments in the college of education should develop better curricula to teach future secondary school teachers in a more professional way As one example of such curricula developments. one important topics of modem physics was integrated to teach the future high school physics teachers In the physics education departments. The title is "The Physics of Solar Constant Measurement The surrounding core physics for this measurements were pulled together with these important points in minds(1) clear goal of learning In the teachers college physics(2) Clear explanation of physics and visualization of important technologies for the high school students(3) these teachings should encourage for the students to use the knowledge and technologies learned through the class toward the industrial applications Korea will move toward one of the heavily industrialized countries in the world where the physics education can become key player to manufacture physics based products. Therefore developments of physics curricula which relates teachers college, high school, and industry will become more and more Important.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.68-68
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• 2010

Electroluminescence (EL) characteristics of green-emission ZnS:Cu,Cl-based ac-type inorganic powder electroluminescent structures were examined by inserting carbon nanotubes (CNTs) into or next to the dielectric layer. For the top-emission type EL structure, where the luminescent light was emitted from the top of the structure, was fabricated by assembling in order, a top electrode, an emitting layer, a dielectric layer, and a bottom electrode from the top. $BaTiO_3$ powder mixed with CNTs was used as a dielectric layer or CNTs were deposited between the bottom electrode and $BaTiO_3$ dielectric layer in order to improve the role of the dielectric layer in the structure. Luminance of an EL structure with CNTs inclusion was greatly enhanced possibly due to the high dielectric constant in the dielectric layer of $BaTiO_3$/CNTs, which is one of hot research topics utilizing nano-objects for intensifying dielectric constant and reducing dielectric loss at the same time. A variation on the CNTs themselves and their inclusion methods in the dielectric layer has been exhorted, and the underlying mechanism for the role of CNTs in the EL structure will be explained in the poster. In order to extend the flexibility of EL devices, EL devices were fabricated on the paper substrate and their performance was compared other EL devices on the plastic-based substrate.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2001년도 춘계학술대회:발표자료
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• pp.285-302
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• 2001

At the present time the desalination technology of sea water for portable water in islands employs the RO method. The technology which needs complicated pretreatment processes with various chemicals can generate secondary water pollution and the high maintenance costs such as replacements of filters and membranes make islanders nearly impossible to operate. The MVRS technology for desalination of sea water however has several advantages such as constant production of quality portable water and capability of managing broad operating load. The variable-speed turbo-type vapor compressors employed in the system can utilize wind energy which is abundant in most Korean islands. Salt as a by-product can be produced by applying solar energy to the salt-concentrated waste water from the system. This paper discusses the relating topics such as technical and economical viabilities of the new MVRS desalination system for the production of portable water and salt as a by-product using new & renewable sources of energy.

• 한국정보시스템학회지:정보시스템연구
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• 제29권1호
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• pp.181-199
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• 2020

Purpose The purpose of this study is to analyze the current state of grounded theory methodology in Korea information systems studies and to suggest its application strategies. Design/methodology/approach After reviewing previous studies, this study reviewed 16 papers which adopted grounded theory methodology and analyzed these papers by two ways, research contents and methods adopted from grounded theory methodology: Main characteristics in grounded theory methodology are selected as main criteria in analysis such as data collection method, constant comparison, software use, coding ways, suggested model, proposition suggestion etc., while subject, theory/practice orientation, and role of prior knowledge are included in research contents. Findings Based on the review and analysis, this paper suggested four guidelines for adopting grounded theory methodology to information systems research in Korea: First, division of research methodology into stages. Second, explicit documentation of research process. Third, pursuit of diversity in research topics. Fourth, strengthening scale up and theoretical integration.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.63-69
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• 2021

Flipped learning is necessary for modern education but quite difficult to implement. In pedagogical science, the question remains to what extent the practical work of the teacher in combination with the technologies of flipped learning will improve the quality of higher education. The aim of this article is to study the effectiveness and feasibility of using flipped learning technologies, assessing their perception by students (advantages and problems), identified an algorithm for introducing flipped learning technology in higher education institutions. Research methods. The main method is an experiment. An evaluation of the effectiveness of the study was conducted using a questionnaire and observation method. Statistical methods were used to evaluate the results of the experiment. The research hypothesis is that flipped learning allows the teacher to spend more time on an individual approach, to understand the real needs of students, and provide effective feedback, thereby improving the quality of learning and motivation of students, especially while studying complex material. The results of the study are to prove the effectiveness of the technology of flipped education in the study of complex disciplines, courses, topics. The use of flipped learning strategies improves the self-regulation of the educational process, group work skills, improves students' ability to learn, overcome difficulties. The technology of flipped learning in the presence of modern technical means and constant work on improving the level of digital literacy is an effective means for students to master complex topics and problematic issues that require additional consideration and discussion. The perspective of further research is the consideration of integrated approaches to the application of flipped learning technologies to the principles of STEAM-education, multilingual and multicultural programs, etc. It is also worth continuing to develop a set of methods aimed at enhancing the student's learning activities, the formation of group work skills, direct participation in creating the foundations of higher education.

• Human Ecology Research
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• 제60권4호
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• pp.625-643
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• 2022

The purpose of this study was to explore the trends and core keywords of the secondary school home economics teacher selection test using content analysis and text network analysis. The sample comprised texts of the secondary school home economics teacher 1st selection test for the 2017-2022 school years. Determination of frequency of occurrence, generation of word clouds, centrality analysis, and topic modeling were performed using NetMiner 4.4. The key results were as follows. First, content analysis revealed that the number of questions and scores for each subject (field) has remained constant since 2020, unlike before 2020. In terms of subjects, most questions focused on 'theory of home economics education', and among the evaluation content elements, the highest percentage of questions asked was for 'home economics teaching·learning methods and practice'. Second, the network of the secondary school home economics teacher selection test covering the 2017-2022 school years has an extremely weak density. For the 2017-2019 school years, 'learning', 'evaluation', 'instruction', and 'method' appeared as important keywords, and 7 topics were extracted. For the 2020-2022 school years, 'evaluation', 'class', 'learning', 'cycle', and 'model' were influential keywords, and five topics were extracted. This study is meaningful in that it attempted a new research method combining content analysis and text network analysis and prepared basic data for the revision of the evaluation area and evaluation content elements of the secondary school home economics teacher selection test.

• 대한전기학회논문지
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• 제44권1호
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• pp.97-103
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• 1995

This paper reports the following two topics : $\circled1$ ozone concentration (O$\sub$3con/) and discharge characteristics in flowing O$\sub$2/ with variation of Re$\sub$3/ at high voltage nozzle (HVN) of HVN 10 type ozonizer. $\circled2$ O$\sub$3con/ with variation of Re$\sub$3/ at HVN of HVN 25 type ozonizer. The important conclusions obtained from this paper are as follows. 1) In HVN 10 type ozonizer : $\circled1$ The discharge pattern can be controlled by adjustment of the Re$\sub$3/. $\circled2$ V$\sub$c/ is inversely proportional to pulse width (P$\sub$w/) and pulse frequency (P$\sub$f) $\circled3$ O$\sub$3con/ increase as decreasing of Re$\sub$3/ for constant P$\sub$w/ and P$\sub$f/. $\circled4$ O$\sub$3con/ increase as decreasing of P$\sub$w/, O$\sub$3con/ is proportional to P$\sub$f/. 2) In HVN 25 type ozonizer : O$\sub$3con/ of HVN 25 type ozonizer can increase than that of HVN 10 type ozonizer, according to parallel circuit of applied voltage and serial of supplied gas. As a result, we can obtain O$\sub$3con/ of 825[ppm] as the maximun value.