• 한국수학사학회지
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• 제11권2호
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• pp.35-42
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• 1998

It is an undecidable problem to determine whether a given equation logically follows from a given set of equations. However, it is possible to give the answer to many instances of the problem, even though impossible to answer all the instances, by using rewrite systems and completion procedures. Rewrite systems and completion procedures can be implemented as computer programs. The new equations such a computer program generates are theorems that hold in the given equational theory. For example, a completion procedure applied on the group axioms generates simple theorems about groups. Mathematics students' teaming to know the existence and mechanisms of computer programs that prove simple theorems can be a significant help to promote the interests in abstract algebra and logic, and the motivation for studying.

• Kyungpook Mathematical Journal
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• 제61권2호
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• pp.223-237
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• 2021

Let n be a fixed natural number. Menger algebras of rank n can be regarded as a canonical generalization of arbitrary semigroups. This paper is concerned with studying algebraic properties of Menger algebras of rank n by first defining a special class of full n-place functions, the so-called a left translation, which possess necessary and sufficient conditions for an (n + 1)-groupoid to be a Menger algebra of rank n. The isomorphism parts begin with introducing the concept of homomorphisms, and congruences in Menger algebras of rank n. These lead us to establish a quotient structure consisting a nonempty set factored by such congruences together with an operation defined on its equivalence classes. Finally, the fundamental homomorphism theorem and isomorphism theorems for Menger algebras of rank n are given. As a consequence, our results are significant in the study of algebraic theoretical Menger algebras of rank n. Furthermore, we extend the usual notions of ordinary semigroups in a natural way.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제18권4호
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• pp.237-256
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• 2014

This paper reports findings from a written assessment which was designed to investigate Chinese primary school students' understanding of the equal sign and equation structure. The investigation included a sample of 110 Grade 3, 112 Grade 4, and 110 Grade 5 students from four schools in China. Significant differences were identified among the three grades and no gender differences were found. The majority of Grades 3 and 4 students were found to view the equal sign as a place indicator meaning "write the answer here" or "do something like computation", that is, holding an operational view of the equal sign. A part of Grade 5 students were found to be able to interpret the equal sign as meaning "the same as", that is, holding a relational view of the equal sign. In addition, even though it was difficult for Grade 3 students to recognize the underlying structure in arithmetic equation, quite a number of Grades 4 and 5 students were able to recognize the underlying structure on some tasks. Findings in this study suggest that Chinese primary school students demonstrate a relational understanding of the equal sign and a strong structural sense of equations in an earlier grade. Moreover, what found in the study support the argument that students' understanding of the equal sign is influenced by the context in which the equal sign is presented.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제4권1호
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• pp.1-22
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• 2000

The purpose of this study was to investigate the effects of using graphing calculators on students' understanding of the linear and quadratic function concepts. The populators of this study are tenth graders at high school in Seoul, one class for the treatment group and another class for the comparison group, and experiment period is 14 weeks including two weeks for school regular exams.Function tests used in the study was proposed which described a conceptual knowledge of functions in terms of the following components: a) Conceptual understanding, b) Interpreting a function in terms of a verbal experission, c) Translating between different representations of functions, and d) Mathematical modeling a real-world situation using functions. Even though the group test means of the individual components of conceptual understanding, interpreting, translating, mathematical modeling did not differ significantly, there is evidence that the two groups differed in their performance on conceptual understanding. It was shown that students learned algebra using graphing calculators view graphs more globally. The attitude survey assessed students' attitudes and perceptions about the value of mathematics, the usefulness of graphs in mathematics, mathematical confidence, mathematics anxiety, and their feelings about calculators. The overall t-test was not statistically significant, but the students in the treatment group showed significantly different levels of anxiety toward mathematics.

• 정보통신설비학회논문지
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• 제10권1호
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• pp.7-13
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• 2011

Matrix multiplication is a fundamental operation of linear algebra and arises in many areas of science and engineering. This paper introduces an efficient parallel matrix multiplication scheme on N ${\times}$ N mesh-connected SIMD array processor, called multiple hierarchical SIMD architecture (HMSA). The architectural characteristic of HMSA is the hierarchically structured control units which consist of a global control unit, N local control units configured diagonally, and $N^2$ processing elements (PEs) arranged in an N ${\times}$ N array. PEs are communicating through local buses connecting four adjacent neighbor PEs in mesh-torus networks and global buses running across the rows and columns called horizontal buses and vertical buses, respectively. This architecture enables HMSA to have the features of diagonally indexed concurrent broadcast and the accessibility to either rows (row control mode) or columns (column control mode) of 2D array PEs alternately. An algorithmic mapping method is used for performance evaluation by mapping matrix multiplication on the proposed architecture. The asymptotic time complexities of them are evaluated and the result shows that paralle matrix multiplication on HMSA can provide significant performance improvement.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제18권3호
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• pp.223-234
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• 2014

Research shows that formative assessment has a more powerful effect on student learning than summative assessment. This case study of an 8th grade algebra classroom focuses on how the implementation of Formative Assessment Lessons (FALs) and the participation in teacher learning communities related to FALs changed in the teacher's instructional practices, over the course of a year, to promote students' mathematical reasoning and justification. Two classroom observations are analyzed to identify how the teacher elicited and built on students' mathematical reasoning, and how the teacher prompted students to respond to and develop one another's mathematical ideas. Findings show that the teacher solicited students' reasoning more often as the academic year progressed, and students also began developing mathematical reasoning in meaningful ways, such as articulating their mathematical thinking, responding to other students' reasoning, and building on those ideas leading by the teacher. However, findings also show that teacher change in teaching practices is complicated and intertwined with various dimensions of teacher development. This study contributes to the understanding of changes in teaching practices, which has significant implications for teacher professional development and frameworks for investigating teacher learning.

• 전자통신동향분석
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• 제36권2호
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• pp.32-42
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• 2021

The rapid growth of deep-learning applications has invoked the R&D of artificial intelligence (AI) processors. A dedicated software framework such as a compiler and runtime APIs is required to achieve maximum processor performance. There are various compilers and frameworks for AI training and inference. In this study, we present the features and characteristics of AI compilers, training frameworks, and inference engines. In addition, we focus on the internals of compiler frameworks, which are based on either basic linear algebra subprograms or intermediate representation. For an in-depth insight, we present the compiler infrastructure, internal components, and operation flow of ETRI's "AI-Ware." The software framework's significant role is evidenced from the optimized neural processing unit code produced by the compiler after various optimization passes, such as scheduling, architecture-considering optimization, schedule selection, and power optimization. We conclude the study with thoughts about the future of state-of-the-art AI compilers.

• Smart Structures and Systems
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• 제13권2호
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• pp.257-280
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• 2014

In this paper, a novel PARAllel FACtor (PARAFAC) decomposition based Blind Source Separation (BSS) algorithm is proposed for modal identification of structures equipped with tuned mass dampers. Tuned mass dampers (TMDs) are extremely effective vibration absorbers in tall flexible structures, but prone to get de-tuned due to accidental changes in structural properties, alteration in operating conditions, and incorrect design forecasts. Presence of closely spaced modes in structures coupled with TMDs renders output-only modal identification difficult. Over the last decade, second-order BSS algorithms have shown significant promise in the area of ambient modal identification. These methods employ joint diagonalization of covariance matrices of measurements to estimate the mixing matrix (mode shape coefficients) and sources (modal responses). Recently, PARAFAC BSS model has evolved as a powerful multi-linear algebra tool for decomposing an $n^{th}$ order tensor into a number of rank-1 tensors. This method is utilized in the context of modal identification in the present study. Covariance matrices of measurements at several lags are used to form a $3^{rd}$ order tensor and then PARAFAC decomposition is employed to obtain the desired number of components, comprising of modal responses and the mixing matrix. The strong uniqueness properties of PARAFAC models enable direct source separation with fine spectral resolution even in cases where the number of sensor observations is less compared to the number of target modes, i.e., the underdetermined case. This capability is exploited to separate closely spaced modes of the TMDs using partial measurements, and subsequently to estimate modal parameters. The proposed method is validated using extensive numerical studies comprising of multi-degree-of-freedom simulation models equipped with TMDs, as well as with an experimental set-up.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제27권4호
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• pp.449-472
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• 2013

본 연구에서는 2006년에 새롭게 출판된 MiC 교과서를 대상으로, Stein 외(2009)가 제안한 바 있는 인지적 요구 정도(cognitive demand level)에 따라 구체적이고 체계적인 분석 기준과 분석틀을 이용하여 MiC 교과서에서 다루고 있는 수학적 과제들의 유형을 분석하고자 하였다. MiC 교과서에서 다뤄지는 내용은 크게 수, 대수, 기하와 측정, 자료 분석과 통계인데, 본 연구에서는 모든 영역의 내용을 다루기에는 너무나 양이 방대하여, 본 연구에서는 학교 안팎의 실생활 소재나 문제 상황이 보다 풍부한 함수 영역을 선정하여 이에 한정하여 다루었다. 다만, MiC 교과서는 level 1, 2, 3의 세 권으로 구분되어 있는데, 함수 내용은 Level 3에만 제시되어 있으므로 본 연구에서는 level 3만을 대상으로 한다. 이 연구를 통하여 궁극적으로 MiC 교과서의 수학적 과제가 얼마만큼 융통성 있게 풍부하게 다뤄지는가를 분석을 통하여 파악해 봄과 동시에, 이로부터 도출된 양질의 결과를 토대로 우리나라 교과서 개발 및 구현을 위한 시사점을 도출하고자 한다.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제34권3호
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• pp.299-324
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• 2020

본 연구에서는 고등학생들의 수학 학습양식, 성격기질별 특징을 확인하고 각 성격기질별로 수학학습 전략을 제시하고자 하였다. 이를 위해, 375명의 고등학교 1학년 학생들을 대상으로 MBTI 성격유형 검사, 수학학습 선호도 조사를 실시하여 그 결과를 분석하였다. 이 연구의 결과는 다음과 같다. 첫째, 많은 학생들이 사교육의 효과를 높게 평가하고 교과서보다는 참고서를 활용한 수학학습을 더 선호하였다. 둘째, 학습 태도, 학습 습관(개념이해 집중도), 문제해결 전략(문제이해 노력, 다양한 전략 사용), 자기 관리(메타인지) 영역에서 성격기질에 따라 통계적으로 유의미한 차이가 확인되었다. 셋째, SJ형 학생들은 마인드맵 등의 학습 전략, SP형 학생들은 장,단기 학습목표를 꾸준히 실천하는 전략이 필요하다. NT형 학생들은 SRN(자기성찰노트)이나 수학일지를 활용한 학습 전략, NF형 학생들은 논리적 근거를 제시하는 수학학습 노트 쓰기 활동과 대수 학습에 더 많은 시간 투자가 필요하다.