• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.151-159
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• 2020

This paper puts forward protection strategies for the environmental problems of Busan coastline, providing theoretical basis and guiding standards for the tourism development and environmental transformation of the coastline. The order of research is to deduce the factors that affect environmental problems from the theoretical coastline development characteristics. The investigation method of spatial structure combined with time axis is adopted, and historical images and image processing techniques are used to find the characteristics of morphological changes of Busan coastline. The three types of natural coastline, artificial coastline and ecological restoration coastline are analyzed through the five factors that affect the fluctuation, extensibility, greening rate, concealment and vision of space. According to the above discussion, international competition examples are introduced to find solutions. Finally, environmental protection schemes are put forward from five aspects of tourism, accidents, development, culture and transformation. In the future research, it will focus on the transformation of coastline space to provide a more humanized activity space for coastline residents.

• School Mathematics
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• v.7 no.2
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• pp.123-137
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• 2005

Elementary combinatorial problem may be classified into three different combinatorial models(selection, distribution, partition). The main goal of this research is to determine the effect of type of combinatorial operation and implicit combinatorial model on problem difficulty. We also classified errors in the understanding combinatorial problem into error of order, repetition, permutation with repetition, confusing the type of object and cell, partition. The analysis of variance of answers from 339 students showed the influence of the implicit combinatorial model and types of combinatorial operations. As a result of clinical interviews, we particularly noticed that some students were not able to transfer the definition of combinatorial operation when changing the problem to a different combinatorial model. Moreover, we have analysed textbooks, and we have found that the exercises in these textbooks don't have various types of problems. Therefore when organizing the teaching , it is necessary to pose various types of problems and to emphasize the transition of combinatorial problem into the different models.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.9
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• pp.89-95
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• 2015

In this paper, we propose a real-time two-dimensional bar code detection system even at long range using a vision technique. We first perform short-range detection, and then long-range detection if the short-range detection is not successful. First, edge map generation, image binarization, and connect component labeling (CCL) are performed in order to select a region of interest (ROI). After interpolating the selected ROI using bilinear interpolation, a location symbol pattern is detected as the same as for short-range detection. Finally, the symbol pattern is arranged by applying inverse perspective transformation to localize bar codes. Experimental results demonstrate that the proposed system successfully detects bar codes at two or three times longer distance than existing ones even at indoor environment.

• Journal of Educational Research in Mathematics
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• v.14 no.1
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• pp.1-17
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• 2004

According to the 7-th curriculum, irrational number should be introduced using repeating decimals in 8-th grade mathematics. To do so, the relation between rational numbers and repeating decimals such that a number is rational number if and only if it can be represented by a repeating decimal, should be examined closely Since this relation lacks clarity in some text books, irrational numbers have only slight relation with repeating decimals in those books. Furthermore, some text books introduce irrational numbers showing that $\sqrt{2}$ is not rational number, which is out of 7-th curriculum. On the other hand, if we use numeral 0 as a repetend, many results related to repeating decimals can be represented concisely. In particular, the treatments of order relation with repeating decimals in 8-th grade text books must be reconsidered.

• School Mathematics
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• v.11 no.1
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• pp.111-129
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• 2009

This paper is about didactical transposition, which is to transpose academic knowledge into practical knowledge intended to teach. The research questions are addressed as follows. 1. Are the 13 mathematics textbooks of the 10-Na level indisputable regarding with the didactical transposition, in terms that the order of arrangement and the way of explaining the knowledge of trigonometric functions being analyzed and that its logical construction and students' understandings are considered? 2. Can some transpositions for easier use of didactical manipulative, for more practical and for more principle based be proposed? To answer these questions, this research examined previous studies of mathematics education, specifically the organization of the textbook and the trigonometric functions, and also compared orders of arranging and ways of explaining trigonometric functions from the perspective of didactical transposition of 13 versions of the 10-Na level reorganized under the 7th curriculum. The paper investigated what lacks in the present textbook and sought a teaching guideline of trigonometric functions(especially about sector and graph, period, characters of trigonometric function, and sine rule).

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.160-165
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• 2003

This study was carried out to investigate the effect of several substrates; used rockwool, several spent mushroom composts, and common used media, such as rockwool and vermiculite, on growth and fruit quality of cucumber. Cucumber grew dramatically in the rockwool+peatmoss (1:2 v/v) (RP) and fine granular rockwool in hydroponic system using Yamaztiki's solution for cucumbers. The yield of cucumber fruit was highest in recycled winter mushroom compost (RW), and followed by 100% perlite (Par), recycled oyster mushroom compost (RO), and RR but there was no significant difference among these three media. Soluble solid and firmness were higher in Per and vermiculite (Ver), and any difference was not found among the others. Vitamin C was not influenced by kind of substrate. The results confirm that several reused or recycled substrates have high possibilities for use as medium for hydroponic culture in cucumber.

• Journal of The Korean Association For Science Education
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• v.24 no.5
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• pp.1028-1038
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• 2004

This study investigated how the 7th national elementary school science curriculum was implemented at science classrooms. Data from surveys with 140 elementary schools, 18 science classroom observations, and in-depth interviews with teachers were used to examine the characteristics of elementary school science instruction. Based on the data, I explored (1)how science curriculum is operated in terms of objectives, contents, methods and evaluation of school science, and (2)how student-centeredness and localization themes are reflected on the reconstructed school science curriculum. It was found that the degree of the reorganization of the national curriculum at the teacher level was minimal. And most of the elementary teachers followed the directions and contents of the science textbook and teacher's guidebook regardless of their own local situations. For most teachers, restructuring science curriculum meant reordering the sequences of the contents, and adding or deleting some units or topics. I also examined why elementary teachers have difficulty in reconstructing science curriculum at the classroom level. The necessity of curriculum reconstruction at the teacher level is also discussed.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.311-322
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• 2009

Using the 3-D analysis, this study winpared and analyzed the 'fade-shot swing' which is one of the golf technique. The subjects of this study were 3 male pro golfers they experimented with only a 7 iron. The purpose was to enhance their performance by producing the important kinematical parameters, finding out the features in them and providing the data to a coach and players. As a result, the position of the club head showed from the outside orbit to the inside orbit. When position of the center of mass moved backwards, the probability of the failure of the fade-shot increased. Cocking angle had an effect on easing the wrist for a smooth follow-through after the impact. It showed that the changes in the shoulder movement was made first and followed by the waist. The hip joint angular velocity achieved a smooth fade-shot motion due to the hitting delay also the velocity of the club-head was faster when uncocking was released at the time of impact.

• Education of Primary School Mathematics
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• v.21 no.2
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• pp.111-130
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• 2018

In this study, I compared and analyzed the contents of Korean, Japanese, Singapore, American, and Finnish textbooks about fraction which is one of the important and difficult concepts in elementary school mathematics. This is aimed to get the implications for meaningful fractional teaching and learning by analyzing the advantages and disadvantages of the methods and time of introducing the concept because fraction has the diversity of the sub-concepts and the introducing methods or process. As a result of the analysis, the fraction was introduced as part-whole(area) in all five countries' textbooks, but the use of number line, conversion between improper fraction and mixed number, whether to deal with part-whole(set) model. Furthermore, there are differences in the methods in obtaining of the equivalent fraction and the order of arrangement in comparison of fraction. Through this analysis, we discussed the reconsideration of the introducing contexts of fractions, the use of number line when introducing fractions, and the problem of segmentation and classification of contents.

• School Mathematics
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• v.16 no.4
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• pp.659-675
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• 2014

The purpose of this study is to investigate the effects of scheme based strategy Instruction on problem solving of word problems of ratio and proportion for students with under achievement or at risk for learning disabilities. Three $7^{th}$ graders of underachieving or at risk LD were participated in this study. Three steps of instructional experiment-testing baseline, intervention with schematic-based strategy, testing for the abilities of problem solving, generalization, & sustainability. The results showed that the schema-based strategy, FOPS was effective method for all three students enhancing problem solving abilities and for generalizing and sustaining the problem solving.