• Journal of Educational Research in Mathematics
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• v.25 no.3
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• pp.281-302
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• 2015

In the current study, answer sheets from 8007 students in 236 Korean schools were selected and analyzed to examine errors that emerge in the process of solving descriptive questions of the National Educational Achievement Assessment in mathematics. Questions used in the analysis were response assessment covering middle school mathematics topics: "mathematical symbols and equations" and "functions." The behavioral domain of the questions was that of "problem solving and computation," which requires establishing an equation for a word problem and allows the calculation of an answer that meets a certain condition. The analysis results revealed various errors in each stage of each question, from understanding to solving; the study attempts to conjecture causes for these errors and draw pedagogical implications.

• Journal for History of Mathematics
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• v.33 no.1
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• pp.1-19
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• 2020

Under 2009 Revised Mathematics Curriculum and 2015 Revised Mathematics Curriculum, mathematics teachers can help students inductively express real life problems related to sequences but have difficulties in dealing with problems asking the general terms of the sequences defined inductively due to 'Guidelines for Teaching and Learning'. Because most of textbooks mainly deal with the simple calculation for the sums of sequences, students tend to follow them rather than developing their inductive and deductive reasoning through finding patterns in the sequences. In this study, we reconstruct 8 problems to find the sums of sequences in MukSaJipSanBup which is known as one of the oldest mathematics book of Chosun Dynasty, using the terminology and symbols of the current curriculum. Such kind of problems can be given in textbooks and used for teaching and learning. Using problems in mathematical books of Chosun Dynasty with suitable modifications for teaching and learning is a good method which not only help students feel the usefulness of mathematics but also learn the cultural value of our traditional mathematics and have the pride for it.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2C
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• pp.117-122
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• 2006

In this paper, we present a simple and general soft bit decision expression for a Gray coded PAM signal over additive white Gaussian noise(AWGN) channel with the log likelihood ratio(LLR). In order to reduce the complexity of the LLR calculation, we make the bitwise LLR expression simple by replacing the mathematical max functions of the conventional Max-Log-MAP expression with simple arithmetic functions associated with some deterministic parameters, such as a received value and distance between symbols on a signal space. Taking the implementation issues, like the area of silicon, the power consumption, the timing latency, and so on, into consideration, we submit that the proposed method is a promising alternative way to conventional methods for reconfigurable systems.

• Korean Journal of Logic
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• v.5 no.1
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• pp.147-157
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• 2001

In this study I try to show some numerical analogy between Leibniz's binary system anc I-ching's symbolic system of duo rerum principia, imagines quator, octo figurae am 64 hexagrams. But, there is really a formal logical accordance in their symbolic foundations, on which are based especially the Wittgenstein's 16 truth-tables in his Tractatus-logico-philosophicus(5.101) am 16 hexagrams, as long as we interpret with the binary values 0 am 1, i.e. the Bi-Polarity, the logical tradition from J. Boole, G. Frege through B. Russell and AN. Whitehead to R. Wittgenstein. So, I argue that the historical and theoretical root of that tradition goes back to the debate between Bouvet and Leibniz about the mathematical structure of I-ching' symbols and the Leibnizian binary arithmetic. In the letter on 4. 11. 1701 from Peking to Leibniz, Bouvet wrote that the I-Ching's symbolism has an analogous structure with Leibniz's binary arithmetic. Corresponding to his suggestion, but without exact knowledge, in the letter of 2. January 1967 to the duke August in Braunschweig-Lueneburg-Wolfenbuettel had Leibniz shown already an original idea for the creation of the world with imago Dei which comes from binary progression, dark and light on water.

• ETRI Journal
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• v.43 no.4
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• pp.660-673
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• 2021

To efficiently use frequency resources, the next 6th generation mobile communication technology must solve the problem of out-of-band emission (OoBE) of cyclic prefix (CP) orthogonal frequency division multiplexing (OFDM), which is not solved in 5th generation technology. This study describes a new zero insertion technique to replace an existing filtering scheme to solve this internal problem in OFDM signals. In the development of the proposed scheme, a precoder with a two-dimensional structure is first designed by generating a two-dimensional mapper and using the specialty of each matrix. A spectral shaping technique based on zero insertion instead of a long filter is proposed, so it can be applied not only to long OFDM symbols, but also very short ones. The proposed method shows that the transmitted signal is completely blocked at the bandwidth boundaries of signals according to the current standards, and it is confirmed that the proposed scheme is ideal with respect to bit error rate (BER) performance because its BER is the same as that of CP-OFDM. In addition, the proposed scheme can transformed into a real time structure through vectorizing process with minimal complexity.

• Education of Primary School Mathematics
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• v.25 no.4
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• pp.343-360
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• 2022

In mathematics classes, the verbal explanation may contain diverse mathematical concepts and principles in short sentences. It may also include mathematics symbols and terms that might not be used in everyday life. Therefore, students may need particular listening ability in order to understand and participate in mathematics communication. Unlike general listening, the listening ability for mathematics classes may require student to integrate their mathematical and linguistic knowledge. The aim of this study is to reveal the subdomains of listening ability for mathematics classes in a elementary school. I categorized listening ability for mathematics classes in a elementary school from the literature. The categories of listening ability for mathematics are Interpretive Listening, Evaluative Listening, Hermeneutic Listening, Selective Listening, Pretend Listening, and Ignored Listening. In order to develop a framework for understanding listening ability for mathematics classes, I investigated a hierarchy of 412 South Korean elementary teachers' perception. Through a web-based survey, the teachers were asked to rank order their beliefs about and students' listening ability. Findings show that teachers' perceptions about listening ability for mathematics classes are divergent from current research trends. South Korean elementary teachers perceived Interpretive Listening as the most important listening.

• Journal of Elementary Mathematics Education in Korea
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• v.5 no.1
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• pp.99-120
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• 2001

The purpose of this thesis is to find the guiding direction of mathematical communication in lower grade students of elementary school and to present a new direction about the effect of using concrete material in communication. It is expected that mathematical communication increases when concrete material is used for the students of the lower grades, who are in concrete operational period. Therefore, this study ai s to investigate what characteristics there are in mathematical communication of second grade students and what effect concrete materials have on mathematical communication and learning. The analysis of the teaching record shows that the second grade students use alternative terms in the process of communication since they are not familiar with mathematical symbols or terms, which is a characteristic of communication in a mathematics class in which concrete material is used. In the process of teaming the students apply their living experiences to their teaming. Since a small number of students lead class, the interaction between students is also led by them. The direction of communication in a small group is not centered around solution of a problem, and most students show a more interest in finding answers than in the process of learning. The effect that concrete material has on communication plays an important role in promoting students' speaking activity; it allows students to identify and correct their errors more easily. It also makes students' activities more predictable, and it increases a small group activities through the medium of concrete material. However, it was also noticed that students' listening activities are not appropriately developed since they do not pay attention to a teacher who uses concrete material. The effects that concrete material has on mathematics class can be summarized as follows. Concrete material promotes students' participation in class by triggering their interest of learning of mathematics and helps them to understand the course of learning. It also helps the teaming and formation of concepts for children of low academic performance. And it makes a phased learning possible according to students' ability to use concrete material and to solve a problem. Based upon the results above mentioned, the use of concrete material is absolutely needed in mathematics classes of lower grade elementary school students since it increases communication and gives much influence on mathematics learning. Therefore, teachers need to develop teaching or learning method which can help increase communication, considering the characteristics of students' communication.

• School Mathematics
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• v.16 no.1
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• pp.135-155
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• 2014

In this paper, we adapted the frame by Lee et al (2013) to investigate to what extent the Korean mathematics textbooks for the 7th graders adapt the principles of Yungbokhap education. The analysis suggests that the textbooks mostly adapt the competence to use language, symbols and texts interactively, and to use knowledge and information interactively. Among the competencies for interacting in heterogeneous groups, the textbooks included the competences to related well to others and to cooperatively work in teams. The competence for acting autonomously was least adapted in the textbooks. The most tasks in the textbooks adapted the monodisciplinary integration and the personal contexts for integration. The results of this research show that Korean mathematics textbooks are limited in implementing the principal dimensions of Yungbokhap education. In the future development of mathematics textbooks, it is necessary to consider how to further reflect the various dimensions of Yungbokhap education to promote students' creativity and autonomy in mathematics class.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.472-486
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• 2000

This paper analysis the performance of joint receiving structure consisting of the decorrelating multiuser detection and beamfromenr-RAKE receive for DS-CDMA communication systems. In asynchronous transmission as the number of simultaneous users increase. the capacity of CDMA system becomes severly reduced due to the nonideal orthogonality between user-assigned PN sequences and improper power control. Accordingly, the CDMA receiving system becomes vulnerable to the multiple access interferences and the near-far problem under multipath fading channel environment. To withstand these undesired performance degradations, this paper proposes the new type of multiuser detection which has a form of the hybrid structure of concatenating beamformer-RAKE receiver and decorrelating multiuser detection. the beam former-RAKE receiver performs temporal and spatial diversity combining with alleviating fading effect and suppressing undesired interferences, and the multiuser detection plays a role of making the receiver robust to the near-far problem. Regarding the individual merit on the usage of either multiuser detection or beamformer-RAKE receiver, the hybrid one is expected to produce the enhanced performance in multipath fading CDMA channel. However major drawback of using decorrelating multiuser detection for practical deployment is arised from its computational complexity , which is exponentially increased as more number of users and transmitted symbols involve. To diminish the computational complexity, this paper exploits an efficient block Toeplitz inversion technique using matrix Levinson polynomial will be introduced. And this paper provided the mathematical analysis to show the efficiency of the proposed joint structure under the multipath propagation environment. And results of a series of exhaustive computer simulations are presented in order to demonstrate the overall performance of the proposed hybrid structure in multipath fading CDMA channel.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.397-405
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• 2021

The purpose of this study is to organize the system of special characters as UX/UI icon design elements, thus laying the groundwork for improvement direction for unclear use regulations. This study examines the theoretical background of UX/UI design and special characters and discovers UX/UI design and special characters' relations and assignments. Besides, the case study summarizes the system of special characters being utilized in the company's UX/UI icon design guidelines to produce the study results. As a result of the analysis, the special character types being utilized in UX/UI were graphic characters, mathematical symbols, punctuation marks, and parentheses. And the special characters commonly used in analysis cases, iOS, Android, and Windows, are ▶, ♥, ★, ○, ⊙, +, ×, ⋯. So this study organizes the common characters to standardize them. Hopefully, this study contributes to increasing the interest in the study of 'special characters' in the UX/UI design field and helps establish a framework for future industrial standards.