• East Asian mathematical journal
• /
• v.29 no.4
• /
• pp.355-392
• /
• 2013

Generally school algebra is to start with introducing variables and algebraic expressions, which have major cognitive obstacles to students in the transfer from arithmetic to algebra. But the recent studies in the teaching school algebra argue the algebraic thinking from an early algebraic point of view. We compare the Korean elementary mathematics textbooks with Americans from this perspective. First, we discuss the history of school algebra in the school curriculum. And Second, we investigate the recent studies in relation to early algebra. We clarify the goals of this study(the importance of early algebra in the elementary school) through these discussions. Next we examine closely the number sense in the arithmetic and the symbol sense in the algebra. And we conclude that the operation sense can connect these senses within early algebra using the algebraic thinking. Finally, we compare the elementary mathematics books between Korean and American according to the components of the operation sense. In this comparative study, we identify a possibility of teaching algebraic thinking in the elementary mathematics and early algebra can be introduced to the elementary mathematics textbooks from aspects of the operation sense.

• Journal for History of Mathematics
• /
• v.25 no.1
• /
• pp.15-27
• /
• 2012

Thomas Harriot(1560-1621) introduced a simplified notation for algebra. His fundamental research on the theory of equations was far ahead of that time. He invented certain symbols which are used today. Harriot treated all answers to solve equations equally whether positive or negative, real or imaginary. He did outstanding work on the solution of equations, recognizing negative roots and complex roots in a way that makes his solutions look like a present day solution. Since he published no mathematical work in his lifetime, his achievements were not recognized in mathematical history and mathematics education. In this paper, by comparing his works with Viete and Descartes those are mathematicians in the same age, I show his achievements in mathematics.

• The Mathematical Education
• /
• v.42 no.5
• /
• pp.697-706
• /
• 2003

In this paper we consider the equality sign as a mathematical concept and investigate its meaning, errors made by students, and subject matter knowledge of mathematics teacher in view of The Model of Mathematic al Concept Analysis, arithmetic-algebraic thinking, and some examples. The equality sign = is a symbol most frequently used in school mathematics. But its meanings vary accor ding to situations where it is used, say, objects placed on both sides, and involve not only ordinary meanings but also mathematical ideas. The Model of Mathematical Concept Analysis in school mathematics consists of Ordinary meaning, Mathematical idea, Representation, and their relationships. To understand a mathematical concept means to understand its ordinary meanings, mathematical ideas immanent in it, its various representations, and their relationships. Like other concepts in school mathematics, the equality sign should be also understood and analysed in vie w of a mathematical concept.

• Journal of Communications and Networks
• /
• v.18 no.2
• /
• pp.182-189
• /
• 2016

The focus in this paper is on obtaining tight, simple algebraic-form bounds and invertible expressions for the average symbol error probability (ASEP) of M-ary phase shift keying (MPSK) in a class of composite fading channels. We employ the mixture gamma (MG) distribution to approximate the signal-to-noise ratio (SNR) distributions of fading models, which include Nakagami-m, Generalized-K ($K_G$), and Nakagami-lognormal fading as specific examples. Our approach involves using the tight upper and lower bounds that we recently derived on the Gaussian Q-function, which can easily be averaged over the general MG distribution. First, algebraic-form upper bounds are derived on the ASEP of MPSK for M > 2, based on the union upper bound on the symbol error probability (SEP) of MPSK in additive white Gaussian noise (AWGN) given by a single Gaussian Q-function. By comparison with the exact ASEP results obtained by numerical integration, we show that these upper bounds are extremely tight for all SNR values of practical interest. These bounds can be employed as accurate approximations that are invertible for high SNR. For the special case of binary phase shift keying (BPSK) (M = 2), where the exact SEP in the AWGN channel is given as one Gaussian Q-function, upper and lower bounds on the exact ASEP are obtained. The bounds can be made arbitrarily tight by adjusting the parameters in our Gaussian bounds. The average of the upper and lower bounds gives a very accurate approximation of the exact ASEP. Moreover, the arbitrarily accurate approximations for all three of the fading models we consider become invertible for reasonably high SNR.

• The Mathematical Education
• /
• v.45 no.2 s.113
• /
• pp.165-176
• /
• 2006

In this paper, we consider changes of algebra strands around the world. And we suggest needs of designing new computer environment where we make and manipulate geometric recursive patterns. For this purpose, we first consider relations among symbols, meanings and patterns. And we also consider Logo environment and characterize algebraic features. Then we introduce L-system which is considered as action letters and subgroup of turtle group. There are needs to be improved since there exists some ambiguity between sign and action. Based on needs of improving the previous L-system, we suggest new commands in JavaMAL microworld. So we design a microworld for recursive patterns and consider meanings of letters in new environments. Finally, we consider the method to integrate L-system and other existing microworlds, such as Logo and DGS. Specially, combining Logo and DGS, we consider the movement of such tiles and folding nets by L-system commands. And we discuss possible benefits in this environment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.9B
• /
• pp.1795-1805
• /
• 1999

In an OFDM (Orthogonal Frequency-Division Multiplexing) system, the sampling frequency offset between the transmitter and receiver is known to cause the interchannel interference (ICI), resulting in performance degradation. In this paper, we propose two time-domain techniques to estimate the sampling frequency offset, especially for a high data-rate OFDM system. The first technique estimates the sampling frequency offset by using the phase difference between two received samples with a fixed amount of time interval, corresponding to the transmitted training symbol, under the assumption of perfect symbol and carrier offset synchronization. The second technique estimates the sampling frequency offset and carrier frequency offset jointly, when the two offsets exist together, by using two training symbols with different frequency components and using a sample algebraic calculation. The proposed estimation techniques for sampling frequency offset cause no time delay due to all time-domain processing, and have a good performance due to no ICI effect. The performances of the proposed techniques are demonstrated by various simulations.

• Journal of the Korean School Mathematics Society
• /
• v.10 no.2
• /
• pp.187-206
• /
• 2007

The purpose of this study is to know what is the difficulties that mathematics underachievers are suffering from the area of mathematical function and how to overcome this difficulties. For this study, we have selected two mathematics underachievers and carried out the inspection. The mathematics underachievers have undergone the difficulties of understanding mathematical problems, the difficulties from the deficit of prerequisite and basic learning, the difficulties of finding the answer typically and the difficulties of classifying an algebraic symbol, the difficulties of calculating the gradient of the straight line passing through two points.

• The Mathematical Education
• /
• v.56 no.1
• /
• pp.81-100
• /
• 2017

The concept of variable is a big idea to develop algebraic thinking. Variable has multiple meanings such as the unknown, a tool for generalization, and the relationship between varying quantities. In this study we analyzed in what ways the meanings of variable were presented in the current elementary mathematics textbooks and workbooks. The results showed that the most frequent meaning of variable was 'the unknown', 'a tool for generalization', and 'the relationship between varying quantities' in order. A close look at the results revealed that the same symbol was often used in representing different values of variable as the unknown. In taking variable as a tool for generalization, questions to provoke generalization were sometimes included not in the textbooks but in the teachers' manuals. The main focus in dealing with variable as the relationship between varying quantities was on finding out the dependent values compared to the independent ones. Building on these results, this study is expected to suggest implications for how to deal with variable concept in elementary mathematics instructional materials.

• Education of Primary School Mathematics
• /
• v.23 no.1
• /
• pp.45-61
• /
• 2020

The concept of equality is given as a way of reading the equal sign without dealing it explicitly in elementary school mathematics. The meaning of the equal sign can be largely categorized as operational and relational views. However, most elementary school students understand the equal sign as an operational symbol for just writing the required answers. It is essential for them to understand a relational concept of the equal sign because algebraic thinking in middle school mathematics is based on students' understanding of a relational view of the equal sign. Recently, the relational meaning of the equal sign is emphasized in arithmetic. Hence it is necessary for elementary school students to have some activities so that they experience a relational meaning of the equal sign. In this study, we investigate the meaning of the equal sign and contexts of the equal sign in elementary school mathematics to discuss explicit ways to emphasize the concept of equality and relational views of the equal sign.

• School Mathematics
• /
• v.16 no.4
• /
• pp.803-825
• /
• 2014

From the early stages of learning algebra, literal symbols are used to represent algebraic objects such as variables and parameters. The concept of parameters contains both indeterminacy and fixity resulting in confusion and errors in understanding. The purpose of this research is to compare the beginners of algebra and pre-service teachers who completed secondary mathematics education in terms of understanding this paradoxical nature of parameters. We recruited 35 middle school students in eight grade and 73 pre-service teachers enrolled in a undergraduate course at one university. Using them we conducted a survey on the perception of the nature of parameters asking if one considers parameters suggested in a problem as variables or constants. We analyzed the collected data using the mixed method of qualitative and quantitative approaches. From the analysis results, we identified several difficulties in understanding of parameters from both groups. Especially, our statistical analysis revealed that the proportions of subjects with limited understanding of the concept of parameters do not differ much in two groups. This suggests that learning algebra in secondary mathematics education does not improve the understanding of the nature of parameters significantly.