• Journal of applied mathematics & informatics
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• v.41 no.3
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• pp.541-552
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• 2023

In 2005, Patterson studied lacunary statistical convergence of double sequences of real numbers and, in 2009, Mursaleen introduced notion of lacunary statistical convergence of single sequences in intuitionistic fuzzy normed space. The current work intends to investigate the lacunary statistical convergence of double sequences and some significant conclusions on the algebra of the lacunary statistical limit of double sequences in intuitionistic fuzzy normed space. In addition, we have studied some examples to support the definitions.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.811-821
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• 2017

This paper intends to propose the direction for improving the welfare space in crew accommodation of fishing vessels engaged in coastal and inshore fishery business in order to solve the phenomenon which young fishers trend to avoid working on fishing vessels. Coastal and inshore fisheries are defined as permitted fisheries business under the Fisheries Act and classified into coastal fisheries and inshore fisheries based on a gross tonnage of 10 tons. Fisheries Act also stipulates the upper limit tonnage regulation and the restrictions on bottoms of fishing vessels permitted for coastal and inshore fisheries to protect fishery resources and to prevent overfishing. It is difficult to increase the welfare space in crew accommodation of fishers under such restrictions because the welfare space in crew accommodation could be secured by reducing the space for the strength of fishing. Therefore, this paper compares the revision trend of the international convention(The Work in Fishing Convention, 2007) and domestic laws on welfare space in crew accommodation of fishing vessels engaged in coastal and inshore fishery business to find out the problems and improvement points in securing the welfare space in crew accommodation of fishing vessels. As a result, it is proposed to revise the Enforcement Ordinance of the Fisheries Act so as to secure the welfare space in crew accommodation of coastal and inshore fishing vessels within the scope of maintaining the maximum allowable tonnage limit regulation by adding an exemption provisions of the restrictions on bottoms of fishing vessels in which case the gross tonnage is increased for securing the spaces for crew accommodation and sanitary facilities of fishers without increasing net tonnage where the bottoms of fishing vessels is increased by renovating or replacing the fishing vessels bigger than the bottoms of fishing vessels permitted within the scope of maintaining the maximum allowable tonnage limit regulation.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.569-575
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• 2006

In this paper, we define the positive and negative limit sets in the hemicompact space and establish their dynamical properties.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.2
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• pp.166-172
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• 2001

We construct several supercategories of ACHY (of approach Cauchy spaces) and AULim (of approach uniform limit spaces) and investigate the relation among them.

• Communications of the Korean Mathematical Society
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• v.28 no.3
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• pp.571-580
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• 2013

In this paper, we extend the familiar limit curve theorem in [2] to a situation where each causal curve lies in a sequence of compact interpolating spacetimes converging to a limit Lorentz space in the sense of Lorentzian Gromov-Hausdorff distance.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.697-705
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• 2011

In this paper, a closed-loop system constructed with a linear plant and nonlinearity in the feedback connection is considered to argue against its planar orbital stability. Through a state space approach, a main result that presents a sufficient stability criterion of the limit cycle predicted by solving the harmonic balance equation is given. Preliminarily, the harmonic balance of the nonlinear feedback loop is assumed to have a solution that determines the characteristics of the limit cycle. Using a state-space approach, the nonlinear loop equation is reformulated into a linear perturbed model through the introduction of a residual operator. By considering a series of transformations, such as a modified eigenstructure decomposition, periodic averaging, change of variables, and coordinate transformation, the stability of the limit cycle can be simply tested via a scalar function and matrix. Finally, the stability criterion is addressed by constructing a composite Lyapunov function of the transformed system.

• Bulletin of the Korean Mathematical Society
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• v.59 no.2
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• pp.481-506
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• 2022

This paper is concerned with the study of various notions of shadowing of dynamical systems induced by a sequence of maps, so-called time varying maps, on a metric space. We define and study the shadowing, h-shadowing, limit shadowing, s-limit shadowing and exponential limit shadowing properties of these dynamical systems. We show that h-shadowing, limit shadowing and s-limit shadowing properties are conjugacy invariant. Also, we investigate the relationships between these notions of shadowing for time varying maps and examine the role that expansivity plays in shadowing properties of such dynamical systems. Specially, we prove some results linking s-limit shadowing property to limit shadowing property, and h-shadowing property to s-limit shadowing and limit shadowing properties. Moreover, under the assumption of expansivity, we show that the shadowing property implies the h-shadowing, s-limit shadowing and limit shadowing properties. Finally, it is proved that the uniformly contracting and uniformly expanding time varying maps exhibit the shadowing, limit shadowing, s-limit shadowing and exponential limit shadowing properties.

• Journal of the Korean Mathematical Society
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• v.49 no.4
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• pp.703-713
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• 2012

In this paper we study ${\omega}$-limit sets and attraction of non-autonomous discrete dynamical systems. We introduce some basic concepts such as ${\omega}$-limit set and attraction for non-autonomous discrete system. We study fundamental properties of ${\omega}$-limit sets and discuss the relationship between ${\omega}$-limit sets and attraction for non-autonomous discrete dynamical systems.

• Journal of the Korean Mathematical Society
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• v.58 no.1
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• pp.207-218
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• 2021

In this paper, the notion of two-sided limit shadowing property is considered for a positively expansive open map. More precisely, let f be a positively expansive open map of a compact metric space X. It is proved that if f is topologically mixing, then it has the two-sided limit shadowing property. As a corollary, we have that if X is connected, then the notions of the two-sided limit shadowing property and the average-shadowing property are equivalent.

• Korean Institute of Interior Design Journal
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• no.26
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• pp.42-48
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• 2001

This study is on the relations between space boundary system and spatial effects. The system is consist of circulation axis & territory and vision axis & vision limit. The former is the spatial characteristic and the later is the time one. The purpose of this case study is confirm the correlation of the both and the spatial effect which is caused by space boundary system. Boundary is enable us to cognize 'territory' and intermediary of each territories. The facts that forms space boundary system are circulation axis & territory and vision axis & vision limit. The space boundary system could be categorized by congregation of these facts. and categorizing is determined with agreement degree of each couple of facts. Categorizing facts on the space boundary system are relevant to spatial effect, especially territory, directness, continuity and concentration.