• 충청수학회지
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• 제32권3호
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• pp.319-326
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• 2019

The concept of the stability is very important in dynamical systems. This paper is devoted to the study some properties of stability on a TVS-cone metric space.

• 대한수학회지
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• 제58권2호
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• pp.439-449
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• 2021

In this paper, we introduce the notions of expansiveness, shadowing property and topological stability for group actions on metric spaces and give a version of Walters's stability theorem for group actions on locally compact metric spaces. Moreover, we show that if G is a finitely generated virtually nilpotent group and there exists g ∈ G such that if Tg is expansive and has the shadowing property, then T is topologically stable.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제30권4호
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• pp.407-416
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• 2023

In this paper, we introduce the concept of C^*-algebra-valued quasi b-metric space and prove some existence and uniqueness theorems. Furthermore, we prove the Hyers-Ulam stability results for fixed point problems via C^*-algebra-valued extended quasi b-metric space.

• 한국측량학회지
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• 제29권3호
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• pp.283-291
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• 2011

측량용 카메라의 경우에는 내부표정을 위해 사진지표 뿐만 아니라 렌즈에 관련된 다양한 매개변수들이 제작사의 정밀 검정을 통해 제공된다. 반면에 비측량용 카메라는 정확한 위치를 알고 있는 다수의 기준점을 이용하여 사용자가 직접 카메라 검정을 통해 내부표정요소를 구하여야 한다. 측량용 카메라는 한번 검정된 내부표정 결과를 장기간 지속적으로 활용하고 있는 것에 반하여, 비측량용 카메라의 경우에는 아직까지 장기간에 따른 내부표정요소의 안정성이 충분히 규명되지 않은 상태이다. 따라서, 비측량용 카메라의 경우 사전측량작업을 할 때마다 내부표정요소를 구하기 위한 작업을 별도로 수행하는 경우가 많다. 이는 다량의 기준점을 이용해야 하므로 매우번거로운 작업이며, 비측량용 카메라의 활용에 장애가 되어 왔다. 본 연구에서는 일반 디지털 카메라에 대해 6개월간에 걸쳐 25회의 카메라 검정과 관측을 주기적으로 실험하여 내부표정요소를 구하고, 이를 분석함으로써 비측량용 카메라의 내부표정요소가 장기간 동안 어느 정도 안정한지를 검토하였다.

• Journal of applied mathematics & informatics
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• 제42권1호
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• pp.93-104
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• 2024

In this paper, we will prove a fixed point theorem for self-mappings on a generalized quasi-ordered metric space which is a generalization of the concept of a generalized metric space with a partial order and we investigate a genralized quasi-ordered metric space related with fuzzy normed spaces. Further, we prove the stability of some functional equations in fuzzy normed spaces as an application of our fixed point theorem.

• Kyungpook Mathematical Journal
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• 제60권4호
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• pp.767-779
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• 2020

This paper primarily discusses and proves the Hyers-Ulam stability of three types of polynomial equations: xn+a1x+a0 = 0, anxn+⋯+a1x+a0 = 0, and the infinite series equation: ${\sum\limits_{i=0}^{\infty}}\;a_ix^i=0$, in dislocated quasi-metric spaces under certain conditions by constructing contraction mappings and using fixed-point methods. We present an example to illustrate that the Hyers-Ulam stability of polynomial equations in dislocated quasi-metric spaces do not work when the constant term is not equal to zero.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2245-2266
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• 2016

The hop count routing metric is widely used in routing protocols of Wireless Sensor Networks (WSNs) due to its simplicity and effectiveness. With a lower hop count route, fewer transmissions are required to send a packet from the source to the destination. This can improve the throughput of a network because fewer transmissions results in less channel contention and interference. Despite this, the hop count routing metric may not be ideal for mobile scenarios where the topology of a network changes constantly and rapidly. In this paper, we propose to increase route stability in mobile WSNs by discovering paths that are more stable during route discoveries using routing metrics. Two routing metrics were proposed, the true beauty of these routing metrics lies in the fact that they can even be used even without specialized hardware such as GPS and other sensors. We implemented the proposed routing metrics in the AODV routing protocol and found that they are highly effective and outperform other stability-based routing metrics and the hop count routing metric.

• 재활복지공학회논문지
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• 제10권2호
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• pp.133-139
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• 2016

전동휠체어는 장애인들이 편리하게 이동할 수 있는 이동수단이다. 하지만 전동휠체어를 사용하다가 전복되는 사고가 매년 증가하고 있다. 현재 전동휠체어 관련한 KS P 7176 규격에는 동적안전성 시험항목이 있지만 이는 전동휠체어의 안전성을 확보하지 못하였다. 본 연구에서는 새롭게 개발한 장애인 차량에 적재 가능한 접이식 전동휠체어를 소개하고 본 휠체어를 기본으로 주행 중 동적 전도해석 기법에 관한 내용을 소개하고자 한다. 전도해석은 force-moment 안정성 측정법을 사용하였으며 회전반경, 가속도, 무게중심점에 대한 영향을 평가하였다. 본 해석 방법으로 전동휠체어의 안정성을 확보할 수 있으며 동적 안정성 평가 항목 개발에 기초자료로 제공할 수 있다.

• International Journal of Aeronautical and Space Sciences
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• 제15권1호
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• pp.63-73
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• 2014

For robust stability analysis of parameters uncertainty missiles, the traditional frequency domain method can only analyze each respective channel at several interval points within uncertain parameter space. Discontinuous calculation and couplings between channels will lead to inaccurate analysis results. A method based on the ${\nu}$-gap metric is proposed, which is able to comprehensively evaluate the robust stability of missiles with uncertain parameters; and then a genetic-simulated annealing hybrid optimization algorithm, which has global and local searching ability, is used to search for a parameters combination that leads to the worst stability within the space of uncertain parameters. Finally, the proposed method is used to analyze the robust stability of a re-entry missile with uncertain parameters; the results verify the feasibility and accuracy of the method.

• 대한수학회논문집
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• 제35권1호
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• pp.287-300
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• 2020

We introduce and study notions of expansivity, topological stability and persistence for Borel measures with respect to time varying bi-measurable maps on metric spaces. We prove that on Mandelkern locally compact metric spaces expansive persistent measures are topologically stable in the class of all time varying homeomorphisms.