• Journal of the Korean School Mathematics Society
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• v.25 no.4
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• pp.375-396
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• 2022

In this paper, to provide an idea for the 2022 revised mathematics curriculum by restructuring the content of the 2015 mathematics curriculum, the content elements of recurring decimals of textbooks, which showed differences in the curriculum of Korea and Japan, were analyzed. As a result of this study, in Korea, before the introduction of the concept of irrational numbers, repeating decimals were defined in the second year of middle school, and the relationship between repeating decimals and rational numbers was dealt with. In Japan, after studying irrational numbers in the third year of middle school, the terminology of repeating decimals is briefly dealt with. Then, when learning the concept of limit in the high school <Mathematics III> subject, the relationship between rational numbers and repeating decimals is dealt with. Based on the results of the study, in relation to the optimization of the amount of learning in the 2022 curriculum revision, implications for the introduction period of the circular decimal number, alternatives to the level of its content, and the teaching and learning methods were proposed.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.5
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• pp.494-499
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• 1990

A new compact hierarchical representation method image is proposed. This method represents a binary image with the set of decimal numbers. Each decimal number represents the pattern of nonterminal node(gray node) in the quadtree. This pattern implies the combination of its four child nodes. The total number of gray nodes is one third of that terminal nodes. We show that gray tree method is efficient comparing with others which have been studied.

• Journal for History of Mathematics
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• v.25 no.4
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• pp.1-10
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• 2012

In Chinese mathematics, there have been two numeral systems, namely one in spoken language for recording and the other by counting rods for computations. They concerned with problems dealing with practical applications, numbers in them are concrete numbers except in the process of basic operations. Thus they could hardly develop a pure theory of numbers. In Song dynasty, 0 and TianYuanShu were introduced, where the coefficients were denoted by counting rods. We show that in this process, counting rods took over the role of the numeral system in spoken language and hence counting rod numeral system plays the role of that for abstract numbers together with the tool for calculations. Decimal fractions were also understood as denominate numbers but using the notions by counting rods, decimals were also admitted as abstract numbers. Noting that abacus replaced counting rods and TianYuanShu were lost in Ming dynasty, abstract numbers disappeared in Chinese mathematics. Investigating JianJie YiMing SuanFa(簡捷易明算法) written by Shen ShiGui(沈士桂) around 1704, we conclude that Shen noticed repeating decimals and their operations, and also used various rounding methods.

• Journal of Korean Library and Information Science Society
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• v.13
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• pp.85-111
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• 1986

Dewey Decimal Classification (DDC) was first published in 1876. Since its first edition it has been revised, on an average, 6 years, and now it has become the widely used library classification system of which the scheme was translated in various languages. The purpose of this study is to find out the chief causes for the development of the DDC. The results of the study can be summarized as follows: 1. It allows materials to be shelved in a relative location as the collection expands. before the DDC was introduced, libraries used a fixed location for materials in which each item was assigned to a certain location set aside for a subject. 2. It is a practical system. The fact that it has survived many storms in the past hundred years and is still the most widely used classification scheme in the world today attests to its practical value. 3. The pure notation of arabic numerals is universally recognizable. People from any cultural or language background can adapt to the system easily. 4. The use of the decimal system enable infinite expansion and sub-division. And it has adaptability for use in libraries of various size and kinds because of its hierarchically expressive notation which permits varying degrees of inclusiveness and exclusiveness within its decimal structure. 5. The notation is simple and easily understood. The self-evident numerical sequence facilitates filing and shelving. And the mnemonic nature of the notation helps the readers to memorize and recognize the class numbers. 6. The relative index brings together different aspects of the same subject scattered in different disciplines. 7. We can avail of DDC numbers for specific titles easily because of its use by many central bibliographic services. 8. It is being continuously revised by a permanent office established in the library of congress in 1933. This office has been responsible for editing all editions of the DDC since the 16th (1958). And the periodic revision at regular intervals ensures the currentness of the scheme. 9. It has adaptability both for conventional (manual) shelf or classed catalogue analysis and also, through its meaningful nation, for retrieval through mechanization and computerized systems.

• School Mathematics
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• v.18 no.3
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• pp.647-666
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• 2016

This study investigates pre-service teacher's understanding of the concept and representations of irrational numbers. We classified the representations of irrational numbers into six categories; non-fraction, decimal, symbolic, geometric, point on a number line, approximation representation. The results of this study are as follows. First, pre-service teachers couldn't relate non-fractional definition and incommensurability of irrational numbers. Secondly, we observed the centralization tendency on symbolic representation and the little attention to other representations. Thirdly, pre-service teachers had more difficulty moving between symbolic representation and point on a number line representation of ${\pi}$ than that of $\sqrt{5}$ We suggested the concept of irrational numbers should be learned in relation to various representations of irrational numbers.

• Journal of Educational Research in Mathematics
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• v.21 no.2
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• pp.121-134
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• 2011

Stevin is known as the inventor of decimal fractions, even though many mathematicians had the concept of decimal fractions and used it before Stevin. Why? To respond to such a question, we studied about its significance which 'La Disme' had in the history of mathematics. These can be summarized as its notational aspect, the manner of developing the book, the conceptual revolution and the practical purpose. And the chapter and verse of are little known when compared to its reputation. So in this paper we considered its contents in detail and discussed some didactical implications in relation to teaching and learning of decimal fractions in elementary school : importance of place values, similarity of calculation to natural numbers, using common fractions to justify, emphasis on the applications of decimal fractions, relation to measuring units, necessity of teaching number sense, using notational aspects.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.4
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• pp.231-250
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• 2011

The purposes of this study are to review characteristics and research areas of environmental studies; to compare and analyze environmental studies in research classifications and Korean societies from Korea Research Foundation(KRF) as well as decimal classification systems such as KDC, DDC, NDC and to suggest several modifications for environmental studies in KDC for the next edition. First of all, environmental philosophy, environmental sociology, environmental education, environmental toxicology, environmental architecture, and environmental geography are suggested to add to the main schedule in KDC and -0276 green technology(environmental technology) is suggested to add to Table 1. Standard subdivision. And new classification numbers for environmental law and environmental public administration are suggested in law and public administration.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.56-65
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• 2016

In this paper, in order to reduce the delay and area of the partial product accumulation (PPA) of the parallel decimal multiplier, a tree architecture that composed by multi-operand decimal CSAs and improved CLA is proposed. The proposed tree using multi-operand CSAs reduces the partial product quickly. Since the input range of the recoder of CSA is limited, CSA can get the simplest logic. In addition, using the multi-operand decimal CSAs to add decimal numbers that have limited range in specific locations of the specific architecture can reduce the partial products efficiently. Also, final BCD result can be received faster by improving the logic of the decimal CLA. In order to evaluate the performance of the proposed partial product accumulation, synthesis is implemented by using Design Complier with 180 nm COMS technology library. Synthesis results show the delay of the proposed partial product accumulation is reduced by 15.6% and area is reduced by 16.2% comparing with which uses general method. Also, the total delay and area are still reduced despite the delay and area of the CLA are increased.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.121-126
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• 2014

The problem of finding the fastest algorithm for multiplication of two large n-digit decimal numbers remains unsolved in the field of mathematics and computer science. To this problem so far two algorithms - Karatsuba and Toom-kook - have been proposed to shorten the number of multiplication. In the complete opposite of shorten the number of multiplication method, this paper therefore proposes an efficient multiplication algorithm using additions completely. The proposed algorithm totally applies shift-and-add algorithm of binary system to large digits of decimal number multiplication for example of RSA-100 this problem can't perform using computer. This algorithm performs multiplication purely with additions of complexity of $O(n^2)$.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.3
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• pp.207-228
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• 2011

The notes of the classification system are to improve the accuracy and consistency of classification by providing useful information on classification numbers and items. Even though, several notes are used in KDC, they are not enough to keep up with rapidly developing and expanding knowledge of nowadays. The purpose of this study is to suggest appropriate types and improvements of the notes in KDC 5th edition. In order to achieve these purposes, transition of notes in KDC was analyzed. Notes of DDC 23rd edition, NDC new 9th edition, and KDC 5th edition were also analyzed. Based upon these comparison and analysis, problem and improvement of notes in KDC were suggested.