• School Mathematics
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• v.19 no.3
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• pp.513-531
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• 2017

This study aims to analyze and compare Korean mathematics textbooks on time and to induce its educational implications. Concretely, the mathematics textbooks from the 1st to the 2009 national revised curriculum were selected for the longitudinal analysis. In each textbook, the contents such as clock reading, units of time, and calculation of elapsed time among various contents about time were chosen. The learning elements and their teaching sequence, the teaching method (the introducing ways of each concept and principle), and the didactical representations are set as an analysis framework. The results of analysis revealed many characteristics and differences in ways of dealing contents about time. Based on these results, we suggested several implications for writing the unit of time in elementary mathematics textbooks and teaching about time in classrooms.

• Journal of the Korean Society of Systems Engineering
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• v.18 no.1
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• pp.66-83
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• 2022

Artificial Intelligence (AI) is to assumed to be one of next generation technology which determine technological competitiveness and strategic advantage of a certain country. By using the patent data, this study aims to have a comparative analysis of the technological competitiveness of evolving artificial intelligence at different stages of development among the five largest intellectual property offices in the world (IP5). For the analysis data, all AI technology patent data from 1956 to 2019 were utilized according to the classification system presented in the "WIPO 2019 Technology Trend: Artificial Intelligence" report published by the World Intellectual Property Organization (WIPO) in 2019. The results shows that China has already surpassed the United States in terms of the number of patent applications in the field of artificial intelligence technology. However, in the domains of the United States, Europe, Japan, and Korea, the technology competitiveness of the United States is far ahead of China. Interestingly, the rate of increase of Korea's technology competitiveness is also very fast, and it has been shown that the technology strength is ahead of China in non-Chinese domains. The significance of this study can be found in the fact that the temporal and spatial change process of technological competitiveness of significant countries in the field of artificial intelligence technology artificial intelligence was viewed as a macro-framework using the technology index (TS) the differences were compared.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.201-208
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• 2008

Statement of problem: A new implant impression technique which use abutments as impression coping, and use resin cement as a splinting material was described. Accuracy of this technique was compared with conventional closed tray and resin splinted open tray technique for a $15^{\circ}$ angled 3-implant model Material and methods: A dental stone master model with 3 linearly positioned implant analogue and a reference framework which was passively fitted to it were fabricated. The center analogue was perpendicular to the plane of model and the outer analogues had a $15^{\circ}$angulation forward or backward. 10 closed tray impressions, 10 resin splinted open tray impressions, 10 abutment-resin framework cementation impressions and 10 abutment-metal framework cementation impressions were made with additional silicone material and poured with dental stone. A light microscope with image processing was used to record the vertical gap dimension between reference framework and analogue of duplicated cast made with each 4 impression techniques. Statistical analysis used one-way ANOVA with post-hoc tests Tukey test of .05 level of significance Results: Significant difference in the vertical gap dimension was found between closed tray technique; 74.3 (${\pm}33.4$)${\mu}m$ and resin splinted open tray technique, and two other new technique. (P<.05) Abutment-metal framework cementation technique;42.5 (${\pm}11.9$)${\mu}m$ was significantly different from resin splinted open tray technique. (P<.05) Abutmentresin framework cementation technique;51.0 (${\pm}14.1$)${\mu}m$ did not differ significantly from resin splinted open tray technique;50.3 (${\pm}16.9$)${\mu}m$. (P>.05) Conclusion: Within limitations of this study, the accuracy of implant level impressions of resin splinted open tray technique was superior to that of closed tray technique. A new technique using abutment and metal framework cementation was more accurate than resin splinted open tray technique.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1147-1156
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• 2015

The result of responsibility supervision system which has been enforced for the last twenty (20) years since January, 1994 is evaluated, and keeps an eye out the process of unification and absorption of the system into the construction management (CM). As a baseline data for this study, the grade framework of construction engineer's ICEC introduced with CM is summarized. In this manuscript, the questionaire survey for CM and ICEC was conducted toward the target group of road field construction engineers and analyzed the outcome of the respondents' answers. 50% of the respondents have answered positively for the question about converting responsibility supervision to CM. 48% of the respondents from construction works field have answered positively for converting responsibility supervision system to CM while 38% of the respondents from engineers of supervision field have answered positively, less positive than the answers from works field engineers. 46% of overall respondents have answered, however, to maintain the present system of 40%, 40% and 20% on the survey to the question asking the opinion on the ways of calculating ICEC to use the rates : 40% of career, 40% of qualification and 20% of academic achievements. However, it appeared that engineers who have comparative advantages with academic achievements and career, and engineers with lower grade qualification demanded higher rate for career.

• Journal of Animal Science and Technology
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• v.55 no.2
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• pp.103-107
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• 2013

A crucial first step in the planning of any scientific experiment is to evaluate an appropriate sample size to permit sufficient statistical power to detect the desired effect. In this study, we investigated the optimal sample size of quantitative trait locus (QTL) linkage analysis for simple random sibship samples in pedigreed chicken populations, under the variance component framework implemented in the genetic power calculator program. Using the program, we could compute the statistical power required to achieve given sample sizes in variance component linkage analysis in random sibship data. For simplicity, an additive model was taken into account. Power calculations were performed to relate sample size to heritability attributable to a QTL. Under the various assumptions, comparative power curves indicated that the power to detect QTL with the variance component method is highly affected by a function of the effect size of QTL. Hence, more power can be achievable for QTL with a larger effect. In addition, a marked improvement in power could be obtained by increasing the sibship size. Thus, the use of chickens is advantageous regarding the sampling unit issue, since desirable sibship size can be easily obtained compared with other domestic species.

• Journal of Korean Elementary Science Education
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• v.35 no.1
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• pp.1-12
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• 2016

The purpose of this study was to analyze question's patterns in elementary school science teacher's guide books of 5, 6th grade under the 2009 revised curriculum. A modified analysis framework based on Blosser's classified system was used to analyze 1,982 questions extracted from elementary science teacher's guide books by grade, by domain, and by teaching and learning stage. The findings of this study were as follows. First, of the 1,982 questions, the most prominent type of question was the propositional question and the following was the reproductive question. And, in comparing the question's patterns between 5, 6th grade, it was found that 6th grade had higher rate of close typed question, while 5th grade had higher rate of open typed question in its curriculum. Secondly, a comparative study about two domains, material and energy science domain and earth and life science domain, showed that the number of questions of each domain was not much different. However, it was found that propositional questions and applicable questions showed a higher rate in material and energy science domain, and anticipated questions and open typed questions including divergent and evaluative question showed higher rate in earth and life science domain. Moreover, although the total number of questions from integration and my fun research domain's contents was small, the rate of open typed questions was higher than any other domains. Finally, as a result of comparing and analyzing question's pattern in teaching and learning stages, the rate of reproductive question and anticipated questions was high at the stage of introduction. At the stage of development, the rate of propositional and reproductive questions was high. At the stage of conclusion, the rate of synthetic and applicable questions was high.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.1-9
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• 2022

In this study, for development of the MDO (Multi Disciplinary Optimization) framework, the flight dynamic characteristic parameters of the ChangGong-91, a light aircraft, were extracted by an analytical method based on various semi-empirical methods, and the flight test method was compared and evaluated. The semi-empirical analysis methods for comparative subjects were the Perkins method, McCormick method, and Smetana method. The major stability/control derivatives and dynamic factors were calculated, using each method. As the comparison criteria, the flight test derivative estimates and dynamic factors were processed, using the output error method. Additionally, the flight characteristics of the light aircraft were analyzed and evaluated according to the provisions of the Korean Airworthiness Standard (KAS) of the Ministry of Land, Infrastructure and Transport, and MIL-F-8785C for the U.S. military.

• Journal of Educational Research in Mathematics
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• v.26 no.3
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• pp.403-420
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• 2016

Some of the critical changes in the revised 2015 Korean Mathematics curriculum were that direct proportion and inverse proportion were moved from elementary school to middle school and that supplementary content related to correlation was included. These decisions were based on comparative studies of international curriculum. Therefore in this study, we selected countries for comparison; United States, England, France, Finland, Australia, Japan, Singapore, China and Taiwan. We looked into the timing and scope for direct/inverse proportion and correlation in curricula of these countries. Along with this, we established four criteria; vertical sequence, horizontal sequence, external connection, and internal connection for an analysis framework. Then we compared and analysed the direct/inverse proportion and correlation in each curriculum. As a result, in most of these curricula, the direct/inverse proportions are introduced at middle school or are introduced at elementary school and then developed further at middle school. Most of curriculums on direct/inverse proportion and correlation match the four criteria. Correlation is introduced in high school mathematics in all counties except Finland and it is dealt in diverse context introducing related concepts, for example, correlation coefficient, regression straight line, and least square. We suggested that it is necessary to refer these international trends for the next revision of curriculum.

• School Mathematics
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• v.16 no.2
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• pp.259-283
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• 2014

This research investigated the Revised mathematics curriculum and the National Achievement Test of Japan that advanced by leaps and bounds in PISA 2012. As compared with Korea, Japan shows similar trends in the affective domain and the cognitive domain of international achievement test. To put it concretely, this research compared and analyzed the mathematics contents domain of the 2009 revised mathematics curriculum of Korea and the 2008 revised mathematics curriculum of Japan being applied. The analysis was conducted in many aspects including overall of Japanese mathematics education system, the contents to be covered in each grade, and the methods of essential learning themes. We compared the mathematics contents dealt with each country based on the framework of analysis such as