• Communications of the Korean Mathematical Society
• /
• v.27 no.4
• /
• pp.733-743
• /
• 2012

In the present paper, we prove common fixed point theorems for single-valued and set-valued occasionally weakly compatible mappings in Menger spaces. Our results improve and extend the results of Chen and Chang [Chi-Ming Chen and Tong-Huei Chang, Common fixed point theorems in Menger spaces, Int. J. Math. Math. Sci. 2006 (2006), Article ID 75931, Pages 1-15].

• The Journal of Korean Physical Therapy
• /
• v.22 no.6
• /
• pp.35-42
• /
• 2010

Purpose: To investigate the rater reliability of a Pediatric Balance Scale (PBS) for children with cerebral palsy, and to investigate possible differences among raters according to their clinical work experience and testing experience. Methods: Study participants included 18 children with spastic cerebral palsy who could walk. They were instructed by pediatric physical therapists, two of whom had ten years of clinical work experience and two who had less than one year of experience. The children's ability to achieve physical balance was videotaped for PBS items. The raters watched the tapes and evaluated each child twice. Rater reliability was analyzed using the intraclass correlation coefficient (ICC). Differences between experienced and novice raters were analyzed using a paired t-test. The statistical significance level was set to 0.05. Results: The total PBS scores averaged 45.78~48.00 and 45.72~47.67 for first and second tests. Intra-rater reliability was very high (ICC=0.89~0.99), and the repeated measurement coincidence was high (p>0.05). Inter-rater reliability was high (ICC=0.83~0.84), but there was a bit of a difference in the coincidence (p<0.05). The experienced raters' reliability and coincidence were higher than those of the novices, and there were differences in reliance and coincidence between experienced and novice raters (p<0.05). Conclusion: Inter-rater and intra-rater reliability is very high. However, rater reliability showed defferences depending on clinical work experience and testing experience. When testing pediatric patients with the PBS, the rater's clinical experience and test experience may affect the test results.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1998.06a
• /
• pp.288-295
• /
• 1998

This paper proposes a new data classification method based on the tolerant rough set that extends the existing equivalent rough set. Similarity measure between two data is described by a distance function of all constituent attributes and they are defined to be tolerant when their similarity measure exceeds a similarity threshold value. The determination of optimal similarity theshold value is very important for the accurate classification. So, we determine it optimally by using the genetic algorithm (GA), where the goal of evolution is to balance two requirements such that (1) some tolerant objects are required to be included in the same class as many as possible. After finding the optimal similarity threshold value, a tolerant set of each object is obtained and the data set is grounded into the lower and upper approximation set depending on the coincidence of their classes. We propose a two-stage classification method that all data are classified by using the lower approxi ation at the first stage and then the non-classified data at the first stage are classified again by using the rough membership functions obtained from the upper approximation set. We apply the proposed classification method to the handwritten numeral character classification. problem and compare its classification performance and learning time with those of the feed forward neural network's back propagation algorithm.

• Journal of applied mathematics & informatics
• /
• v.28 no.5_6
• /
• pp.1359-1378
• /
• 2010

The effect of impulse in the ecological models makes them more realistic. Recently, the eco-epidemiological models have become an important field of study from the both mathematical and ecological view points. In this article, we consider some eco-epidemiological systems under the influence of impulsive force. A set of sufficient conditions for the permanence of the system are derived. Stability of the trivial solution and at least one strictly positive periodic solution are obtained. Numerical examples are given in support to our analytical findings. Finally, a short discussion concludes the paper.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.25 no.1
• /
• pp.16-25
• /
• 2021

This paper is studied the existence of a solution for the impulsive Cauchy problem involving the Caputo fractional derivative in Banach space by using topological structures. We based on using topological degree method and fixed point theorem with some suitable conditions. Further, some topological properties for the set of solutions are considered. Finally, an example is presented to demonstrate our results.

• Advances in Computational Design
• /
• v.5 no.3
• /
• pp.277-289
• /
• 2020

This article describes the technology for constructing of a multiply-connected three-dimensional area's finite element representation. Representation of finite-element configuration of an area is described by a discrete set that consist of the number of nodes and elements of the finite-element grid, that are orderly set of nodes' coordinates and numbers of finite elements. Corresponding theorems are given, to prove the correctness of the solution method. The adequacy of multiply-connected area topology's finite element model is shown. The merging of subareas is based on the criterion of boundary nodes' coincidence by establishing a simple hierarchy of volumes, surfaces, lines and points. Renumbering nodes is carried out by the frontal method, where nodes located on the outer edges of the structure are used as the initial front.

• The Korean Journal of Financial Management
• /
• v.1 no.1
• /
• pp.1-27
• /
• 1985

One of the most important research works in modern business enterpise is the relation between the purpose of business enterprise and decision making behavior of manager. It is because the coincidence of the former and the latter is considered an ideal type in evaluating the result of business management. Here I have set up assumptions in order to solve the above statements: (1) What purpose does the modern business enterprise set up and what kind of economic background does it have? (2) What is the theory of maximization of stock value among the purposes of business enterprise? (3) What kind of decision making do we do in the maximization of stock value in busiess administration? (4) How is the behavior of business financial manager's intention and decision made? The result pursued under the above assumptions shows that business manager's behavior of decision making is affected according to the degree that he gets some information, but basically is determined in consideration of his autonomous standpoint, namely the stability of business enterprise and the stability of manager himself while he faithfully performs his duty which is entrusted by stockholders. Therefore we come to the conclusion that there is a little gap between a manager's behavior of decision-making and the purpose of stock value maximization.

• Journal of applied mathematics & informatics
• /
• v.17 no.1_2_3
• /
• pp.195-215
• /
• 2005

In this paper, we investigate the dynamics of the mathematical model of two non-interacting preys in presence of their common natural enemy (predator) based on the non-autonomous differential equations. We establish sufficient conditions for the permanence, extinction and global stability in the general non-autonomous case. In the periodic case, by means of the continuation theorem in coincidence degree theory, we establish a set of sufficient conditions for the existence of a positive periodic solutions with strictly positive components. Also, we give some sufficient conditions for the global asymptotic stability of the positive periodic solution.

• Journal of applied mathematics & informatics
• /
• v.34 no.1_2
• /
• pp.115-143
• /
• 2016

The concept of quasi-coincidence of interval valued intuitionistic fuzzy point with an interval valued intuitionistic fuzzy set is considered. By using this idea, the notion of interval valued (α, β)-intuitionistic fuzzy bi-ideals, (1,2)ideals in a semigroup introduced and consequently, a generalization of interval valued intuitionistic fuzzy bi-ideals and intuitionistic fuzzy bi-ideals is defined. In this paper, we study the related properties of the interval valued (α, β)-intuitionistic fuzzy bi-ideals, (1,2) ideals and in particular, an interval valued (Є, Є ∨q)-fuzzy bi-ideals and (1,2) ideals in semigroups will be investigated.

• Journal of applied mathematics & informatics
• /
• v.32 no.3_4
• /
• pp.405-426
• /
• 2014

The concept of interval-valued (${\alpha},{\beta}$)-fuzzy ideals, interval-valued (${\alpha},{\beta}$)-fuzzy generalized bi-ideals are introduced in LA-semigroups, using the ideas of belonging and quasi-coincidence of an interval-valued fuzzy point with an interval-valued fuzzy set and some related properties are investigated. We define the lower and upper parts of interval-valued fuzzy subsets of an LA-semigroup. Regular LA-semigroups are characterized by the properties of the lower part of interval-valued (${\in},{\in}{\vee}q$)-fuzzy left ideals, interval-valued (${\in},{\in}{\vee}q$)-fuzzy quasi-ideals and interval-valued (${\in},{\in}{\vee}q$)-fuzzy generalized bi-ideals. Main Facts.