• Nonlinear Functional Analysis and Applications
• /
• 제28권2호
• /
• pp.497-520
• /
• 2023

Numerous problems in science and engineering defined by nonlinear functional equations can be solved by reducing them to an equivalent fixed point problem. Fixed point theory provides essential tools for solving problems arising in various branches of mathematical analysis, such as split feasibility problems, variational inequality problems, nonlinear optimization problems, equilibrium problems, complementarity problems, selection and matching problems, and problems of proving the existence of solution of integral and differential equations.The theory of fixed is known to find its applications in many fields of science and technology. For instance, the whole world has been profoundly impacted by the novel Coronavirus since 2019 and it is imperative to depict the spread of the coronavirus. Panda et al. [24] applied fractional derivatives to improve the 2019-nCoV/SARS-CoV-2 models, and by means of fixed point theory, existence and uniqueness of solutions of the models were proved. For more information on applications of fixed point theory to real life problems, authors should (see [6, 13, 24] and the references contained in).

• 천문학논총
• /
• 제30권2호
• /
• pp.709-711
• /
• 2015

In modern Astronomy the vernal equinoctial (VE) point is taken as the starting point for measuring celestial longitudes. Due to the precession of equinoxes, the above point is receding back along the ecliptic. As a result, the longitudes of fixed stars are increasing every year. In ancient India, the Hindu astronomers did not favour the idea of fixed stars changing their longitudes. In order to stabilize the zodiac, they had taken as the origin a point which is fixed on the ecliptic and as such is quite different from the VE point. This initial point being a fixed one, the longitude of stars measured from this origin remain invariable for all time. There was an epoch in the past when this initial point coincided with the VE point and thus the epoch may be called the zero-year. There is controversy over the determination of the zero-year. The reasons for the choice for the fixed zodiacal system by the Hindu astronomers as well as the epoch of zero-year have been found out on the basis of information available in various astronomical treatises of ancient India written in Sanskrit.

• 충청수학회지
• /
• 제25권4호
• /
• pp.617-631
• /
• 2012

In this paper, we will consider some existence theorems of common fixed points for a countable family of non-self multi-valued mappings defined on a closed subset of a complete metrically convex space, and give more generalized common fixed point theorems for a countable family of single-valued mappings. The main results in this paper generalize and improve many common fixed point theorems for single valued or multi-valued mappings with contractive type conditions.

• Korean Journal of Mathematics
• /
• 제16권1호
• /
• pp.51-55
• /
• 2008

Let f be an analytic function with a simple zero in the reals or the complex numbers. An extraneous fixed-point of an iteration function is a fixed-point different from a zero of f. We prove that all extraneous fixed-points of Laguerre-like iteration functions and general Laguerre-like functions are repulsive.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제13권2호
• /
• pp.147-153
• /
• 2013

Previously, Park et al. (2005) defined an intuitionistic fuzzy metric space and studied several fixed-point theories in this space. This paper provides definitions and describe the properties of type(${\beta}$) compatible mappings, and prove some common fixed points for four self-mappings that are compatible with type(${\beta}$) in an intuitionistic fuzzy metric space. This paper also presents an example of a common fixed point that satisfies the conditions of Theorem 4.1 in an intuitionistic fuzzy metric space.

• 대한수학회지
• /
• 제43권1호
• /
• pp.1-9
• /
• 2006

Based on the Schauder fixed point theorem, we give a Leray-Schauder type fixed point theorem for countably condensing mappings in a more general setting and apply it to obtain eigenvalue results on condensing mappings in a simple proof. Moreover, we present a generalization of Sadovskii's fixed point theorem for count ably condensing self-mappings due to S. J. Daher.

• 한국통신학회논문지
• /
• 제31권6A호
• /
• pp.593-602
• /
• 2006

본 논문에서는 IEEE 802.16e에 기반한 OFDMA TDD 시스템 하향 링크 트래픽 채널의 fixed-point 구현을 위해 Floating-point 모델로부터 성능 열화와 하드웨어 복잡도를 최소화 할 수 있도록 적절한 비트 사이즈를 결정하는 방법론에 대하여 기술한다. Fixed-point 구현에 있어서 여러 가지 고려 사항 중 하나는 비트 사이즈를 절사하는 방법에 따른 Saturation과 Quantization의 선택이며, 반드시 주의해야 할 점은 신호의 분포를 정확히 파악한 후 신호의 분포에 맞도록 Saturation과 Quantization 중 하나의 비트 절사방법을 적절히 적용시켜야 한다는 점이다. 또한, 시행착오를 거치면서 여러 비트 사이즈에 대하여 모의 실험을 수행하여야만 성능 열화를 최소화 하면서 원하는 비트 사이즈를 얻을 수 있다. 본 논문에서는 수신단의 트래픽 채널에 최적화된 비트 사이즈를 결정하기 위하여 AWGN 및 ITU-R M.1225의 Veh-A 채널 환경에서 컴퓨터 모의 실험을 수행한다.

• East Asian mathematical journal
• /
• 제17권1호
• /
• pp.19-32
• /
• 2001

In this paper, we give some common fixed point theorems for five and six mappings satisfying the Mann-type iteration in Banach spaces. We improve some results of Gornicki and Rhoades, Khan and Imdad, Cho, Fisher and Kang, Cirick and many others.

• 대한수학회보
• /
• 제38권4호
• /
• pp.669-677
• /
• 2001

Three new fixed point theorems are presented for the set valued maps of Idzik. Moreover a continuation theorem for such maps is also given.

• 호남수학학술지
• /
• 제34권1호
• /
• pp.77-84
• /
• 2012

In this paper, we define the weakly commuting mapping and prove the fixed point theorem for weakly commuting mappings under some conditions on intuitionistic fuzzy metric spaces.