• Bulletin of the Korean Mathematical Society
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• v.46 no.2
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• pp.373-385
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• 2009

An m${\times}$n Boolean matrix A is called regular if there exists an n${\times}$m Boolean matrix X such that AXA = A. We have characterizations of Boolean regular matrices. We also determine the linear operators that strongly preserve Boolean regular matrices.

• The Mathematical Education
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• v.53 no.4
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• pp.493-507
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• 2014

The purpose of this study is to analyze how high school students form and interpret the mental image in the process of solving regular polyhedron problems. For this purpose, a set of problems about the regular polyhedron's vertex is developed on the base of the regular polyhedron's duality and circulation. and applied to 2 students of the 12th graders in D high school. After 2 hours of teaching and learning and another 2 hours of mental image-analysis process, the following research findings are obtained. Fisrt, a student who recorded medium high-level grade in the national scholastic test can build the dynamic image or the patten image in the process of solving regular polyhedron's vertex problems by utilizing the 3D geometry program. However, the other student who recorded low-level grade can build the concrete-pictorial image. Second, pattern image or dynamic image can help students solve the regular polyhedron's vertex problems by proper transformation of informations and the mental images while the concrete-pictorial image does not help. Hence, it is recommended that the mathematics teachers should develop teaching and learning materials about the regular polyhedron's duality and circulation and also give students suitable questions to build the various mental images.

• Child Health Nursing Research
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• v.10 no.4
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• pp.451-459
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• 2004

Purpose:　The purpose of this study is to identify how regular stimulation affects apnea of a premature infant. Method: This study was used a within-subjects design with repeated measure using GEE (General Estimating Equation) and had been conducted from July 1, 2003 to March 12, 2004. The subjects consisted of 11 apneic premature infants who had showed apnea more than twice for 12 hours. A regularly vibrating test lung was provided to the subjects to find how regular stimulation affects apnea. Result: From the result of regular stimulation for apneic premature infants, both the lowest SaO2 and the lowest heart rate at experimental period were found to be increased significantly. However, the decreased frequency of the apnea cases was not statistically effective. Conclusion: These findings indicate that regular stimulation for apneic premature infants could be effective on increasing both SaO2 and heart rate. Therefore, we suggest regular stimulation to be used clinically to heal apnea of premature infants.

• The Pure and Applied Mathematics
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• v.7 no.2
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• pp.71-78
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• 2000

Any Hausdoroff space on a set which has at least two points a regular closed Boolean algebra different from the indiscrete regular closed Boolean algebra as indiscrete space. The Sierpinski space and the space with finite complement topology on any infinite set etc. do the same. However, there is $T_{0}$ space which does the same with Hausdorpff space as above. The regular closed Boolean algebra in a topological space is isomorphic to that algebra in the space with its open extension topology.

• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.409-417
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• 2009

A definition of finite automaton (DFA and NDFA) with intuitionistic fuzzy (final) states is proposed. Acceptance of intuitionistic fuzzy regular language by the finite automaton (DFA and NDFA) with intuitionistic fuzzy (final) states are examined. It is found that the finite automaton (DFA and NDFA) with intuitionistic fuzzy (final) states is more suitable for recognizing intuitionistic fuzzy regular language than earlier model. The paper also gives an idea of intuitionistic fuzzy regular expressions through possible definitions.

• Honam Mathematical Journal
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• v.29 no.3
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• pp.481-493
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• 2007

We will construct several types of semi-regular tilings of a hyperbolic unit disk model by defining geometric features of the definition of distance in a hyperbolic plane, area of triangle, and isometry of inversions. We researched the method of regular tilings and semi-regular tilings of hyperbolic unit disk model and wrote an semi-regular tiling construction algorithm using Cabri2 program and Cinderella program. Lastly, We want to make a product related to traditional heritage cultural patterns using Photoshop, so we'll model the advertising photos of cites; Seoul, Gwangju.

• Journal of applied mathematics & informatics
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• v.42 no.2
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• pp.333-351
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• 2024

In this paper, the concept of Pythagorean fuzzy sets are used to describe in semigroups. Then, some characterizations of regular (resp., intra-regular) semigroups by means of Pythagorean fuzzy left (resp., right) ideals and Pythagorean fuzzy (resp., generalized) bi-ideals of semigroups are investigated. Furthermore, the class of both regular and intra-regular semigroups by the properties of many kinds of their Pythagorean fuzzy ideals also being studied.

• Asia-Pacific Journal of Business
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• v.13 no.2
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• pp.95-106
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• 2022

Purpose - The purpose of this study was to examine the mediating effect of employee competence on the relationship between the utilization of non-regular workers and firm performance. Design/methodology/approach - This study utilized 427 firm level data from HCCP. The Exploratory Factor Analysis (EFA) and the multiple regression analysis were conducted to verify the hypotheses. Findings - We found that the utilization of non-regular workers is not significantly related to firm performance. However, the utilization of non-regular workers had a negative relationship with employee competence, and that employee competence mediated the relationship between the utilization of non-regular workers and firm performance. Research implications or Originality - As environmental uncertainty and competition between firms intensify, more and more firms are utilizing non-regular workers. Research on the relationship between the utilization of non-regular workers and firm performance is continuously conducted, but research on the process of explaining the specific relationship between them is still insufficient. Our study contributes the related research area by identifying the mediating role of employee competence on the utilization of non-regular workers and firm performance relationship.

• Bulletin of the Korean Mathematical Society
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• v.50 no.2
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• pp.627-637
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• 2013

Let [$n$] = {1, 2, ${\ldots}$, $n$} be ordered in the standard way. The order-preserving full transformation semigroup ${\mathcal{O}}_n$ is the set of all order-preserving singular full transformations on [$n$] under composition. For this semigroup we describe maximal subsemibands, maximal regular subsemibands, locally maximal regular subsemibands, and completely obtain their classification.

• East Asian mathematical journal
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• v.22 no.1
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• pp.61-69
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• 2006

A near-ring N is reduced if, for $a{\in}N,\;a^2=0$ implies a=0, and N is left strongly regular if for all $a{\in}N$ there exists $x{\in}N$ such that $a=xa^2$. Mason introduced this notion and characterized left strongly regular zero-symmetric unital near-rings. Several authors ([2], [5], [7]) studied these properties in near-rings. Reddy and Murty extended some results in Mason to the non-zero symmetric case. In this paper, we will define a concept of strong reducedness and investigate a relation between strongly reduced near-rings and left strongly regular near-rings.