• The Journal of the Acoustical Society of Korea
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• v.5 no.3
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• pp.5-12
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• 1986

음성 신호 처리분야에서 고속이며 정확히 기본 주파수를 추출하는 방법은 중요하며, 이를 위한 많은 연구가 제안되어 왔다. 이러한 방법들은 보통 성도의 방해를 제거한 후에 기본 주파수를 검출하기 때문에 지금까지는 처리과정이 복잡하다. 우리는 그러한 과정을 간단히 처리할 수 ldt는 inverse rate type filtering 법을 제안하였다. 제안된 방법은 유한 길이의 정수 계산이고 덧셈과 뺄셈으로 처리될 수 있기 때문에 범용 마이크로 컴퓨터에 의해서도 실시간 처리를 할 수 있게 된다.

• Journal of the Korean School Mathematics Society
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• v.17 no.2
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• pp.235-249
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• 2014

In this paper, teaching contents in area between Korea and Japan's first grade math textbooks are compared. Based on the results of this comparison, implications for improving our grade 1 math textbooks are obtained as follows. Firstly, when describing the configuration of two-digit numbers, it needs to be considered that, after the mathematical description of a concrete material representing two-digit numbers, then it should be processed mathematically. Secondly, with respect to the composition and decomposition of numbers, use of the expression of 'some number and some number' needs to be considered. Thirdly, when reading addition expression and subtraction expression with an equal sign, the way of reading them with terms 'sum' and 'difference' respectively needs to be reconsidered. Fourthly, use of the distinct expression for the supplementing situation and the merging situation respectively and use of the distinct expression for the removing situation and the comparing situation respectively need to be considered. Fifthly, the jump in representing the expression of subtraction of two numbers as the expression of the subtraction or mixed operation of three numbers to explain (some number)-(some number) with borrowing need to be resolved.

• Journal of Elementary Mathematics Education in Korea
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• v.4 no.1
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• pp.21-37
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• 2000

Although methods about teaching basic principles and skills of addition and subtraction is long traditional, view points of interpreting those algorithms and ways of introducing those calculating skills are various according to textbooks at each historical stage of elementary mathematics curriculum development in Korea. The 1st and 2nd stage shows didactic transpositions less systemic. In the 3rd and 4th stage, didactic devices, which were influenced by the new math, for help of understanding the principles of addition and subtraction muchly depends on mathematical and logical mechanism rather than psychological and intellectual structure of students who learn those algorithms. Relatively compromising and stable forms appear in the 5th and 6th stages. Didactic transpositions in the 7th stage focus on the formation of mathematical concepts by exploration activities rather than on the presentation of mathematical contents by text. Anyone who wishes to design an elementary mathematics textbooks based upon the constructive view should consider the suggestions derived from such transition.

• Journal of the Korean School Mathematics Society
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• v.17 no.3
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• pp.409-435
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• 2014

This study examines relations between the 5th graders' fraction operation skills and error types on constructed-response items. As results, first, the participants have lower fraction operation skills on 'multiplication of fraction' than 'addition and subtraction of fraction'. Second, the participants have different error types depend on their constructed-response items. Most of error types which group with high ability made was 'leap of solving process', both groups error type with medium ability as well as low ability is 'misunderstanding of questions'. Third, the operation skills on 'addition and subtraction of fraction' have an influence on their operation skills on 'multiplication of fraction', and error types of 'understanding of questions' and 'understanding of solving process' have the most effects on the influence.

• Journal of the Korean School Mathematics Society
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• v.25 no.4
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• pp.307-332
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• 2022

This action research was carried out to help students learn fractions computation by making and using semi-concrete fraction manipulatives that can be used continuously in math classes. For this purpose, the researcher and students made semi-concrete fraction manipulatives and learned how to use these through reviewing the previously learned fraction contents over 4 class sessions. Afterward, through the 14 classes (7 classes for learning to reduce fractions and to a common denominator, 7 classes for adding and subtracting fractions with different denominators) in which the principle inquiry learning model was applied, students actively engaged in learning activities with fraction manipulatives and explored the principles underneath the manipulations of fraction manipulatives. Students could represent various fractions using fraction manipulatives and solve fraction computation problems using them. The achievement evaluation after class found that the students could connect the semi-concrete fraction manipulatives with fraction representation and symbolic formulas. Moreover, the students showed interest and confidence in mathematics through the classes using fraction manipulatives.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.3
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• pp.599-617
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• 2011

This study is aimed at finding some drawbacks of current elementary mathematics textbooks and to give suggestions for ongoing new textbooks according to 2009 revised curriculums, by comparing and analyzing Korean textbooks and chinese textbooks of People's Education Press. The areas are confined to number concepts, addition and subtraction for comparative analyzing. The results are followings: Korea textbooks have more verbal expressions, designated instructive activities for students to do, similar algorithm applied for enlarging mathematical concepts, bigger number concepts and number usage of operations, and monotonous number sense activities. Therefore Korean textbooks, compared to China's, is more weaker in areas such as encouraging student's interest, in challenging mathematics, and in forming fundamental mathematical concept.

• East Asian mathematical journal
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• v.31 no.4
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• pp.505-525
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• 2015

The purpose of this study is to analyze teaching method of addition and subtraction of whole number in Korea and New Zealand lower grade textbook and to get some suggestive points to develop mathematics curriculum and for a qualitative improvement of textbook. To do this, we will analyze focusing on teaching material, type and method of teaching, cases of real teaching and in the case of New Zealand, we will analyze portfolios together to see what kind of things do they deal with related to addition and subtraction. From these analyzing, the results are as follows: First, the guideline of accomplishment of group of year are stated in 2009 revised curriculum in Korea but it is rough. On the other hand, the level of accomplishment from kindergarten to high school are stated divided by eight kinds of thing in New Zealand curriculum. Second, there were common and different points in the aspect of teaching material. The common points are that both of our Korea and New Zealand are using materials related to real life intimately and the diifferent points are to use technology such as calculator and computer. They are more widely used in New Zealand than our Korea. Third, Korea had used routine method mainly but New Zealand had used method to develop creativity of learner such as to write problem corresponding to expression, posing problem corresponding to information, to complete table and find pattern and to write word problem to explain pattern and so on. Fourth, we could see special calculation strategies in the case of teaching addition and subtraction such as concept of double, compensation, various strategy based on counting of number, addition of the same number, magic square, near-double which are not finding in our mathematics textbook. Fifth, in the New Zealand textbook they had used teaching methods inducing curiosity of learner such as finding message and puzzle problem than solving given problem simply.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.1
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• pp.1-6
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• 2008

There are many possible representations in denoting both positive and negative numbers in the binary number system to be applicable to the complexity of the hardware implementation, arithmetic speed, appropriate application, etc. Among many possibilities, the signed-magnitude representation, which keeps one sign bit and magnitude bits separately, is intuitively appealing for humans, conceptually simple, and easy to negate by flipping the sign bit. However, in the signed-magnitude representation, the actual arithmetic operation to be performed may require magnitude comparison and depend on not only the operation but also the signs of the operands, which is a major disadvantage. In a simple conceptual approach, addition/subtraction of two signed-magnitude numbers, requires comparator circuits, selective pre-complement circuits, and the adder circuits. In this paper circuits to obtain the difference of two numbers are designed without adopting explicit comparator circuits. Then by using the difference circuits, a universal signed-magnitude adder/subtracter is designed for the most general operation on two signed numbers.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.2
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• pp.185-205
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• 2013

In this study, to begin with, it was discussed to gather vocabularies which are expected to be vocabularies related to four fundamental rules of arithmetic and classify them according to kinds and groups, to demarcate vocabularies related to four fundamental rules of arithmetic for using in elementary school mathematics which are associated with addition, subtraction, multiplication, and division directly. Next, the basic vocabularies related to four fundamental rules of arithmetic were discussed. At this time, regarding vocabularies related addition, subtraction, multiplication, and division as coming from the verb add, subtract, multiply, divide respectively, vocabularies that contains the stem of each verb were considered as the basic vocabularies related to four fundamental rules of arithmetics. Following it, vocabularies which assist the operation and indicate the result of the operation were included, then, vocabularies related to four fundamental rules of arithmetic for using in elementary school mathematics were demarcated and presented according to the following criteria. First, a newly coined verb or derivative using the noun form of a certain verb as a root should not be used. Second, such vocabularies of which examples do not exist or rarely exist in textbooks/workbooks should not be used, even though they are registered in mathematics glossary book published by ministry of education or Korean dictionary published by the national institute of Korean language. Third, vocabularies which are not replaceable and vocabularies which have some didactical reasons for using them should be used.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.651-654
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• 2008

In finite field operations based on $GF(2^m)$, additions and subtractions are easily implemented. On the other hand, multiplications and divisions require mathematical elaboration of complex equations. There are two dominant way of approaching the solutions of finite filed operations, normal basis approach and polynomial basis approach, each of which has both benefits and weakness respectively. In this study, we adopted the mathematically feasible polynomial basis approach and suggest the optimization techniques of finite field operations based of mathematical principles.