• International Journal of Internet, Broadcasting and Communication
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• 제9권1호
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• pp.72-80
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• 2017

In this work, an efficient transmit antenna selection approach for the quadrature spatial modulation (QSM) systems is proposed. The conventional Euclidean distance antenna selection (EDAS)-based schemes in QSM have too high computational complexity for practical use. The proposed antenna selection algorithm is based on approximation of the EDAS decision metric employed for QSM. The elimination of imaginary parts in the decision metric enables decoupling of the approximated decision metric, which enormously reduces the complexity. The proposed method is also evaluated via simulations in terms of symbol error rate (SER) performance and compared with the conventional EDAS methods in QSM systems.

• East Asian mathematical journal
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• 제37권3호
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• pp.307-317
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• 2021

In this paper, we deal with a problem to determine the type of automorphisms of the unit disc in ℂ in terms of intrinsic geometry. We will characterize the hyperbolicity and parabolicity of automorphism by the distance function of the Poincaré metric.

• Korean Journal of Mathematics
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• 제27권4호
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• pp.861-877
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• 2019

The aim of this paper is to extend some existing fixed point results for asymptotically regular mappings to fuzzy metric spaces. For this purpose some contractive type conditions with respect to an altering distance function are used. Some new common fixed point results have been derived for such mappings. We provide suitable examples to justify our study.

• Journal of applied mathematics & informatics
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• 제36권1_2호
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• pp.93-105
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• 2018

There are many metric functions in the plane. In this paper we are to classify the metric functions on the plane using two ways such as using sum of distances between some points when start point and end point is fixed, and using area of transferred triangle consisted of distances between 3 points.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.967-976
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• 2010

In recent times control functions have been used in several problems of metric fixed point theory. Also weak inequalities have been considered in a number of works on fixed points in metric spaces. Here we have incorporated a control function in certain weak inequalities. We have established two fixed point theorems for mapping satisfying such inequalities. Our results are supported by examples.

• Korean Journal of Mathematics
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• 제26권2호
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• pp.307-326
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• 2018

In this paper, we derive some fixed point theorems in fuzzy metric spaces for self mappings satisfying different contractive type conditions. Some of these theorems generalize some results of Wairojjana et al. (Fixed Point Theory and Applications (2015) 2015:69). Several examples in support of the theorems are also presented here.

• Korean Journal of Mathematics
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• 제30권2호
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• pp.375-389
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• 2022

In this paper, we prove some fixed-point theorems in partially ordered fuzzy metric spaces for (𝜙, 𝜓, 𝛽)-Geraghty contraction type mappings which are generalization of mappings with Geraghty contraction type condition. Application of the derived results are shown in proving the existence of unique solution to some boundary value problems.

• East Asian mathematical journal
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• 제39권1호
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• pp.11-21
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• 2023

Non-trivial automorphisms of the unit disc in the complex plane can be classified by three classes; elliptic, parabolic and hyperbolic automorphisms. This classification is due to a representation in the projective special linear group of the real field, or in terms of fixed points on the closure of the unit disc. In this paper, we will characterize this classification by the distance function of the Poincaré metric on the interior of the unit disc.

• Nonlinear Functional Analysis and Applications
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• 제28권4호
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• pp.1097-1113
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• 2023

In this paper, we extend some fixed point theorems in rectangular b-metric spaces using subadditive altering distance and establishing the existence and uniqueness of fixed point for Hardy-Roger type mappings. Our result generalizes many known results in fixed point theory. Finally, we offer a example to illustrate our result.

• 조명전기설비학회논문지
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• 제20권6호
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• pp.18-25
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• 2006

야간도시경관의 미적향상, 시각적 안전의 확보 및 빛 공해 방지 등을 고려한 기존의 경관조명 평가방법은 대부분 측정점을 한 지점으로 한정하여 조명물리량을 분석함으로써 거리에 따른 평가결과의 다양성이 소홀히 취급되었다. 본 연구는 측정거리의 변화에 따른 평가대상 구조물의 표면휘도를 고려한 경관조명 평가방법을 제시하는데 연구의 목적이 있다. 이를 위하여 경관조명이 설치된 한강의 교량을 대상으로 CS-100과 ProMetric 1400 등 디지털 측광기기와 경관조명 소프트웨어 Lightscape v3.2를 활용하였다. 즉 측정거리 100[m], 300[m], 500[m]로 구분하여 현장측정 및 컴퓨터 시뮬레이션을 실시한 결과 거리변화에 따른 휘도의 평가방법은 대상 구조물로부터 약 100[m] 이내에서 실시하는 것이 휘도측면에서 유리한 것으로 나타났다.