• East Asian mathematical journal
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• v.18 no.2
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• pp.271-282
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• 2002

Let R be a ring with an endomorphism $\sigma$ and a derivation $\delta$. An ideal I of R is ($\sigma,\;\delta$)-ideal of R if $\sigma(I){\subseteq}I$ and $\delta(I){\subseteq}I$. An ideal P of R is a ($\sigma,\;\delta$)-prime ideal of R if P(${\neq}R$) is a ($\sigma,\;\delta$)-ideal and for ($\sigma,\;\delta$)-ideals I and J of R, $IJ{\subseteq}P$ implies that $I{\subseteq}P$ or $J{\subseteq}P$. An ideal Q of R is ($\sigma,\;\delta$)-semiprime ideal of R if Q is a ($\sigma,\;\delta$)-ideal and for ($\sigma,\;\delta$)-ideal I of R, $I^2{\subseteq}Q$ implies that $I{\subseteq}Q$. The ($\sigma,\;\delta$)-prime radical (resp. prime radical) is defined by the intersection of all ($\sigma,\;\delta$)-prime ideals (resp. prime ideals) of R and is denoted by $P_{(\sigma,\delta)}(R)$(resp. P(R)). In this paper, the following results are obtained: (1) $P_{(\sigma,\delta)}(R)$ is the smallest ($\sigma,\;\delta$)-semiprime ideal of R; (2) For every extended endomorphism $\bar{\sigma}$ of $\sigma$, the $\bar{\sigma}$-prime radical of an Ore extension $P(R[x;\sigma,\delta])$ is equal to $P_{\sigma,\delta}(R)[x;\sigma,\delta]$.

• East Asian mathematical journal
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• v.31 no.2
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• pp.211-244
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• 2015

The arithmetic operation have double-sided character. One is calculation as a process, the other is understanding in results as an outcome of the operation. We harbored suspicion on students' misunderstanding in an outcome of the operation, because the curriculum has focused on the calculation, as a process of arithmetic operation. This study starts with the presentation of this problem, we tried to find the recognition ability and character in the arithmetic operation. We researched the recognition ability for 7th grade 27 students who have enough experience in arithmetic operation when studying in elementary school. And we had an interview with 3students individually, that has an error in understanding in results of arithmetic operation but has no error in calculation. We focused on 3students' detailed appearance of the ability to understand in results of arithmetic operation and analysed the changing appearance after recommending unit record using operation expression. As a result, we could find the abily to underatanding in results of arithmetic operation and applicability to recommend unit record using operation expression. Through these results, we suggested educational implications in understanding in results of arithmetic operation.

• East Asian mathematical journal
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• v.33 no.4
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• pp.381-411
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• 2017

The purpose of this study is to investigate how students' mathematical creativity changes through problem-solving instruction using problem-posing for elementary school students and to explore instructional methods to improve students' mathematical creativity in school curriculum. In this study, nonequivalent control group design was adopted, and the followings are main results. First, problem-solving lessons with problem-posing had a significant effect on students' mathematical creativity, and all three factors of mathematical creativity(fluency, flexibility, originality) were also significant. Second, the lessons showed meaningful results for all upper, middle, and lower groups of pupils according to the level of mathematical creativity. When analyzing the effects of sub-factors of mathematical creativity, there was no significant effect on fluency in the upper and middle groups. Based on the results, we suggest followings: First, there is a need for a systematic guidance plan that combines problem-solving and problem-posing, Second, a long-term lesson plan to help students cultivate novel mathematical problem-solving ability through insights. Third, research on teaching and learning methods that can improve mathematical creativity even for students with relatively high mathematical creativity is necessary. Lastly, various student-centered activities in math classes are important to enhance creativity.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.1215-1224
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• 2021

This research aims to discuss the relationship between the courage, anticipation, and satisfaction comprehensively. This study will be complemented by gratitude as a variable that moderates the relationship between courage and anticipation, as well as the relationship between the courage and satisfaction. The large area as survey location is the reason for sampling conducted in 2 stages: (1) taking 15 districts through judgement sampling, (2) allocated sub-districts sample through proportional random sampling. The sample used in this study were 155 sub-districts in East Java. Respondents in each sub-district consisted of 1 farmer and 1 field extension officer to get a total of 310 respondents. The analysis method used to test the hypothesis was Structural Equation Modeling (SEM). The findings of this research are: (1) The courage of field extension officers' have a positive but non-significant direct effect on farmers' anticipation, however, the effect significantly strengthen with religiosity as moderation; (2) The courage of field extension officers' and farmers' anticipation have a significant and positive effect on satisfaction. This study will be complemented by gratitude as a variable that moderates the relationship between the courage and anticipation, as well as the relationship between courage and satisfaction.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.927-938
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• 2021

Small and Medium Enterprises (SMEs) is one of several activators that drives the economy of Indonesia because SMEs provide jobs, increase Gross Domestic Product (GDP), and assure the delivery of products and services. However, Indonesian SMEs are not very competitive in the industrial world, and one of the causes is the low quality of products that undermine customer satisfaction. There are several factors presumed as influencing customer satisfaction, which among others include product knowledge, service quality, and competitive advantage. The objective of this research is to reveal the contribution of product knowledge and service quality to customer satisfaction with competitive advantage as the mediation variable. This research used a quantitative approach. The causal relationship across variables was examined with Structural Equation Modeling-Partial Least Squares (SEM-PLS). The sample of this research involved 140 respondents. Data was collected through a questionnaire and the items in the questionnaire were processed with a software called SmartPLS version 3.3.2. Results of this research indicate (1) product knowledge and service quality can increase competitive advantage and customer satisfaction in East Java SMEs; (2) competitive advantage can act as a mediator in the effect of service quality on customer satisfaction (3) product knowledge can increase customer satisfaction but the increase is not significant statistically.

• East Asian mathematical journal
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• v.39 no.2
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• pp.93-117
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• 2023

The aim of this study is to explore the pre-service math teachers' characteristics of education to develop their AI literacy and SW competency, and to derive some implications. We conducted a 14-hours AI and SW education program for pre-service teachers with theory and practice, and an analysis on class observation data, video frames of classes and interview, Python programming assignments and papers. The results of this case study for 3 pre-service teachers are as follows. First, two students understood artificial neural network and deep learning system accurately, furthermore, all students conducted a couple of explorations related with performance improvement of deep learning system with interest. Second, coding and exploration activities using Python improved students' computational thinking as well as SW competency, which help them give convergence education in the future. Third, they responded positively to the necessity of AI literacy and SW competency development, and to applying coding to math class. Lastly, it's necessary to endeavor to give a coding education to the student's eye level according to his or her prerequisite and to ease the burden of student's studying AI technology.

• East Asian mathematical journal
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• v.40 no.1
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• pp.1-23
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• 2024

Let M be a semi-invariant submanifold of codimension 3 with almost contact metric structure (𝜙, 𝜉, 𝜂, g) in a complex space form M_n+1(c). We denote by A, K and L the second fundamental forms with respect to the unit normal vector C, D and E respectively, where C is the distinguished normal vector, and by R_𝜉 = R(𝜉, ·)𝜉 the structure Jacobi operator. Suppose that the third fundamental form t satisfies dt(X, Y) = 2𝜃g(𝜙X, Y) for a scalar 𝜃(≠ 2c) and any vector fields X and Y , and at the same time R_𝜉K = KR_𝜉 and ∇_{𝜙∇𝜉𝜉}R_𝜉 = 0. In this paper, we prove that if it satisfies ∇_𝜉R_𝜉 = 0 on M, then M is a real hypersurface of type (A) in M_n(c) provided that the scalar curvature $\bar{r}$ of M holds $\bar{r}-2(n-1)c{\leq}0$.

• East Asian mathematical journal
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• v.34 no.4
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• pp.371-402
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• 2018

The researchers set up a research question to find out how to teach the concept of a right triangle through classification activities after listening to the conversations of fellow teachers about the recently revised textbooks. First, a questionnaire was created to confirm the objectivity of the research problem, data were collected through online and offline, and interviews were conducted with some of the respondents. As a result, it confirmed that there was a considerable difference in the perception of the research study about the direction of revising the curriculum called 'student participation centered' and 'the possibility of achieving the learning objective'. Then, we analyzed the critical interpretations used in the third grade math textbook Lesson 2. 'Plane Figure' part 4 and 5. Finally, by analyzing the results of the recognition analysis and textbook analysis, we proposed two learning methods which can link the triangle classification activity and the right triangle concept. Based on the results of the research, we obtained suggestions that a teaching should be made regarding that the classification process may be changed according to the student's prior knowledge and the process of classification activities may be different according to the viewpoint and classification criteria.

• East Asian mathematical journal
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• v.25 no.3
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• pp.321-341
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• 2009

The purpose of this study was to examine the effect of the manipulative materials in the Australian Maths 300 program by applying it to Korean Elementary Mathematics Education - based on parts of 'Probability and Statistics', and 'Symbol and Expression'. In order to this purpose, we select appropriate Maths 300's manipulate materials that could be used to obtain learning objectives within class time for each part, four lessons with the materials were taught at to third, fourth, and fifth grade students of elementary School. The effect of the teaching was analyzed by videotape and student opinion. The results of this study are the following: First, the manipulative tools were almost entirely lacking for the 'Probability and Statistics' section without a 'number of cases' unit. The tools presented in the 'Symbol and Expression' section were helpful in the games that were used for checking preceding learning. Second, the results of using the Math 300 manipulative materials in class showed that the students were eager to be involved in the activities using those materials and to find their own solutions in problem-solving questions that were suited to them; these led to them making their own questions. In response to questioning about the use of the manipulative materials, the students stated that it was easy and fun for them to use the manipulative materials, to solve the problems for themselves, and that they would like to continue practicing the activities in the future. Finally, Studies on the presentation of a variety of manipulative materials including those in this study that can used in problem-solving learning and other learning fields, and the methodology for the use of manipulative materials can be enhanced through further studies.

• East Asian mathematical journal
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• v.6 no.2
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• pp.167-182
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• 1990

The relationships between submodules of a module and ideals of the endomorphism ring of a module had been studied in [1]. For a submodule L of a moudle M, the set $I^L$ of all endomorphisms whose images are contained in L is a left ideal of the endomorphism ring End (M) and for a submodule N of M, the set $I_N$ of all endomorphisms whose kernels contain N is a right ideal of End (M). In this paper, author defines an H-invariant module and proves that every submodule of an H-invariant module is the image and kernel of unique endomorphisms. Every ideal $I^L(I_N)$ of the endomorphism ring End(M) when M is H-invariant is a left (respectively, right) principal ideal of End(M). From the above results, if a module M is H-invariant then each left, right, or both sided ideal I of End(M) is an intersection of a left, right, or both sided principal ideal and I itself appropriately. If M is an H-invariant module then the ACC on the set of all left ideals of type $I^L$ implies the ACC on M. Also if the set of all right ideals of type $I^L$ has DCC, then H-invariant module M satisfies ACC. If the set of all left ideals of type $I^L$ satisfies DCC, then H-invariant module M satisfies DCC. If the set of all right ideals of type $I_N$ satisfies ACC then H-invariant module M satisfies DCC. Therefore for an H-invariant module M, if the endomorphism ring End(M) is left Noetherian, then M satisfies ACC. And if End(M) is right Noetherian then M satisfies DCC. For an H-invariant module M, if End(M) is left Artinian then M satisfies DCC. Also if End(M) is right Artinian then M satisfies ACC.