• School Mathematics
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• v.11 no.3
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• pp.479-496
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• 2009

Some children can construct a basic concept of addition and subtraction during the preschool years. Children start to experience mathematics via numbers and their of operations and contact with various contexts of addition and subtraction. In special, word problems reflect mathematics which is appliable to real life. In this paper, I analyse the types of word problems in text book and its students' responses. First, I analyse the types of addition word problems which consist of change add-into situations and part-part-whole situations. Second, I analyse the types of subtraction word problems which consist of change take-away situations, compare situations and equalize situations. Third, I analyse the students' responses by the types of word problems in addition and subtraction. And 115 2nd grade elementary school students participated in this survey. The following results have been drawn from this study. First, the proposition of word problems of part-part-whole situations is higher than that of change add-into situations and the proposition of word problems of take-away situations is higher than that of compare situations and equalize situations. According to the analysis about students' responses, It is no difference between change add-into situations and part-part-whole situations. But the proposition of word problems of take-away situations is higher than that of compare situations and equalize situations. This results from word problems which contain unnecessary information in problem. So, we have to present the various word problems to students.

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.2
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• pp.183-198
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• 2018

In this paper, I theoretically considered joining and separating activities and revisited the textbooks from 7 countries and Korean mathematics textbooks from 5th revised curriculum to 2015 revised curriculum to find implication for the treatment of 0 in the joining and separating activities. The 'joining' has definition and properties similar to addition, but the 'separating'is difficult to define and is not considered to have properties similar to subtraction. In the sense of computation, joining and separating can be seen as' part-part-to-whole' situations, but are just part of the addition and subtraction situations. The analysis of textbooks from 7 counties showed that Singapore and Malaysia textbooks already studied zero and then included it in joining and separating activities, but other countries did not include it as joining and separating activities. The textbooks of South Korea have consistently suggested not to include zero, but teacher's guide has shown that there is a little consistency in the treatment of zero. As a conclusion, I suggested that it was necessary to propose a proper context of the situation in order to introduce joining and separating without including 0 in terms of student level and to propose that a more consistent presentation of zero handling in the teaching in the teacher's guide.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.2
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• pp.309-341
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• 2017

This study aims to investigate an approach to teach percentages in elementary mathematics class by analyzing calculating strategies with percentage the students use to solve the percentage tasks and their percentages of correct answers, as well as types of errors with percentages the students make. For this research 182 sixth graders were examined. The instrument test consists of various task types in reference to the previous study; the percentages tasks are divided into algebraic-geometric, part whole-comparison-change and find part-find whole-find percentage tasks. According to the analysis of this study, percentages of correct answers of students with percentage tasks were lower than we expected, approximately 50%. Comparing the percentages of correct answers according to the task types, the part-whole tasks are higher than the comparison and change tasks, the geometric tasks are approximately equal to the algebraic tasks, and the find percentage tasks are higher than the find whole and find part tasks. As to the strategies that students employed, the percentage of using the formal strategy is not much higher than that of using the informal strategy, even after learning the formal strategy. As an insightful approach for teaching percentages, based on the study results, it is suggested to reinforce the meaning of percentage, include various types of the comparison and change tasks, emphasize the informal strategy explicitly using models prior to the formal strategy, and understand the relations among part, whole and percentage throughly in various percentage situations before calculating.

• Korean Journal of English Language and Linguistics
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• v.1 no.2
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• pp.295-309
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• 2001

The simple forms in English have mostly been investigated in terms of tense, especially by those who do not distinguish between tense and aspect in English. However, we often find some usages of the simple forms that do not seem to fit in any of the meanings of tense. The purpose of this paper is to find aspectual meanings out of the simple present and past forms by re-analyzing their meanings in terms of aspect. It turns out that they represent the perfective aspect seeing a situation as a whole with no beginning. middle and end. As for the controversial stative situations in the simple forms, they have been proven to show the perfective aspect, too, if we agree to see both the part and whole in state as having the same features. And syntactic evidences from the simple forms and their corresponding progressive forms compared also show that the habitual dynamic situations represent the same aspect in the simple forms.

• Research in Mathematical Education
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• v.24 no.2
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• pp.111-130
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• 2021

This exploratory study focuses on analyzing three mathematics textbooks in Germany, Singapore and South Korea to reveal similarities and differences in their introductions of fraction concepts. Findings reveal that all three countries' textbooks introduce fraction concepts predominantly by using pictorial representations such as area models, but the introductions of multiple fraction constructs vary. The Singaporean and South Korean textbooks predominantly used a part-whole construct to introduce fractional concepts while the German textbook introduced various constructs sequentially in the first pages using several scenarios from different real-life situations. The findings were represented using visual representations, which we called textbook signatures. The textbook signatures provided configurations of the textbook features across the three countries. At the end of paper, we share insights and limitations about the use of textbook signatures in the research on textbook analysis.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.9-26
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• 2000

Eventually so as to realize the construction safety, 1 found out the cause of accident and specificities of the construction industry. This study presented to several situations and problems on construction safety. As a result of this study, the below matters must be improved for more effective the construction safety management system. 1. It need to introduce the total construction safety management system. Because there is not effectiveness in the current safety management to the first on the construction field. a. We must consider the safety in the whole parts of the process of the construction and constructors of each part must devide responsibility of the construction safety as a CDM(The Construction Designed Management) used in UK. b. It is desirable to proceed control of safety in the whole parts of the construction to introduce the total safety coordinator that can consult the matters of safety as a law accepted in EU. c. Like management of the construction safety in USA, direction of the construction safety must be made to work exactly by code or manual. d. To improve the organization of the construction safety on the construction field unefficient, it must be introduced safety supervisor, safety coordinator or institutionalization of safety consultant. 2. The law of the construction safety not only have wasteful element but also decrease efficiency by overlapping of regulation, The Ministry of Labour and The Ministry of Construction & Transportation, So laws related with safety must be instituted. a. To realize total safety management, The Ministry of Labour must legislate the basic law about safety management in whole field. b. To legislate the construction safety under one law, and improve efficiency of the overlapping of regulation and the similar law by The Ministry of Construction & Transportation. c. It must be made the law of construction safety that can proper to change of situation in construction. d. The standard of safety must be instituted belong to international level and improved by year. e. We must improve irrational regulation to realize activity of safety self regulating for progress competition in construction industry

• School Mathematics
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• v.12 no.3
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• pp.439-454
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• 2010

This study presents how two eighth grade students generated their own algorithms in the context of fraction measurement division situations by modifications of unit-segmenting schemes. Teaching experiment was adopted as a research methodology and part of data from a year-long teaching experiment were used for this report. The present study indicates that the two participating students' construction of reciprocal relationship between the referent whole [one] and the divisor by using their unit- segmenting schemes and its strategic use finally led the students to establish an algorithm for fraction measurement division problems, which was on par with the traditional invert-and-multi- ply algorithm for fraction division. The results of the study imply that teachers' instruction based on understanding student-generated algorithms needs to be accounted as one of the crucial characteristics of good mathematics teaching.

• School Mathematics
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• v.14 no.2
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• pp.191-212
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• 2012

In the field of arithmetic in mathematics education, there has been lack of fine-grained investigations addressing the relationship between students' construction of division knowledge with fractional quantities and their whole number division knowledge. This study, through the analysis of part of collected data from a year-long teaching experiment, presents a possible constructive itinerary as to how a student could modify her unit-segmenting scheme to deal with various fraction measurement division situations: 1) unit-segmenting scheme with a remainder, 2) fractional unit-segmenting scheme. Thus, this study provides a clue for curing a fragmentary approach to teaching whole number division and fraction division and preventing students' fragmentary understanding of the same arithmetical operation in different number systems.

• Korean Institute of Interior Design Journal
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• no.13
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• pp.216-223
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• 1997

Considering the current rise in elderly population, institutions and facilities caring for the elderly are currently unable to satify the growing needs of the aged wanting the better qualities of life. Therefore, this study will analyze institutions and policies for the elderly in Japan, which has already experienced the rise in elderly population about 30 years earlier than Korea. Because the living conditions of Japan is somewhat similar to that of Korea, analyzing its solutions, both governmental and private, will help better understand the current situations of Korea and possibly offer guidelines as to better serve the growing demands of the aged. In Japan, the social welfare policies directed at caring for the elderly are mainly directed by the government: however, the private services tend to be more adroit at meeting the ever-changing demands of the elderly. Incidentally, the privately owned elderly homes of Japan are a major part of so called the "Silver Industries". The elderly home that are run by private corporations consititute 50 percent of all private institutions for the elderly. These homes tend tobe situated in a city, or near a city environment, serving 25 to 99 people. The types of such homes can be classified from A to D,E,F, reflecting the various services offered by such homes meeting the various demands by the elderly populatiov. Analyzing the social tred of Japan for theelderly, it can be said that the responsibility of the elderly should not only be relied upon the government, but to the society as whole, both public and private. The ever-changing demands of the elderly, wanting better qualities of life, can be better served by systematic analysis of the demands and the various solutions to such demands. Also, the necessary governmental policies in support of elderly welfare, will be needed.be needed.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.789-807
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• 2012

The purpose of this paper is to find various disparity factors in conjunction with situations and contexts of the contents that cause viewer's discomfort, which is to make a content production guideline for viewer's safety, eventually. As a methodology, we extract the experimental data by letting various viewers push a pre-defined key as long as they feel discomfort during watching stereo 3D contents. For each contents, we extract the disparities and disparity changes for the focal point, vicinity of the focal point (ROI, region of interest), and the whole image. For each contents, each point or part of contents is analyzed to find the factors causing discomfort with the two prepared data with watching the contents in 3D. Then, all the analyzed data are re-analyzed to find the strength of each factor. The results from the analyses are explained from the factors having relatively high strength first. It includes the factors that are not known as well as the ones that we can already guess.