• 제목/요약/키워드: contraction mapping

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COINCIDENCE POINT RESULTS FOR (𝜙, 𝜓)-WEAK CONTRACTIVE MAPPINGS IN CONE 2-METRIC SPACES

  • Islam, Ziaul;Sarwar, Muhammad;Tunc, Cemil
    • 호남수학학술지
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    • 제43권2호
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    • pp.305-323
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    • 2021
  • In the present paper, utilizing (𝜙, 𝜓)-weak contractive conditions, unique fixed point and some coincidence point results have been studied in the context of cone 2- metric spaces. Also, our obtained results generalize some results from cone metric space to cone 2-metric space. For the authenticity of the presented work, a non trivial example is also provided.

COUPLED FIXED POINT THEOREMS OF SOME CONTRACTION MAPS OF INTEGRAL TYPE ON CONE METRIC SPACES OVER BANACH ALGEBRAS

  • Akewe, Hudson;Olilima, Joshua;Mogbademu, Adesanmi
    • 호남수학학술지
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    • 제43권2호
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    • pp.269-287
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    • 2021
  • In this paper, we prove some coupled fixed point theorems satisfying some generalized contractive condition in a cone metric space over a Banach algebra. We also applied the results obtained to show coupled fixed point of some contractive mapping of integral type.

GENERAL MIXED HARMONIC VARIATIONAL INEQUALITIES

  • Jong Kyu Kim;Avinash Lakhnotra;Tirth Ram
    • Nonlinear Functional Analysis and Applications
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    • 제29권2호
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    • pp.517-526
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    • 2024
  • In this paper, some iterative methods are used to discuss the behavior of general mixed-harmonic variational inequalities. We employ the auxiliary principle technique and g-strongly harmonic monotonicity of the operator to obtain results on the existence of solutions to a generalized class of mixed harmonic variational inequality.

MODIFIED KRASNOSELSKI-MANN ITERATIONS FOR NONEXPANSIVE MAPPINGS IN HILBERT SPACES

  • Naidu, S.V.R.;Sangago, Mengistu-Goa
    • Journal of applied mathematics & informatics
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    • 제28권3_4호
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    • pp.753-762
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    • 2010
  • Let K be a nonempty closed convex subset of a real Hilbert space H. Let T : K $\rightarrow$ K be a nonexpansive mapping with a nonempty fixed point set Fix(T). Let f : K $\rightarrow$ K be a contraction mapping. Let {$\alpha_n$} and {$\beta_n$} be sequences in (0, 1) such that $\lim_{x{\rightarrow}0}{\alpha}_n=0$, (0.1) $\sum_{n=0}^{\infty}\;{\alpha}_n=+{\infty}$, (0.2) 0 < a ${\leq}\;{\beta}_n\;{\leq}$ b < 1 for all $n\;{\geq}\;0$. (0.3) Then it is proved that the modified Krasnoselski-Mann iterative sequence {$x_n$} given by {$x_0\;{\in}\;K$, $y_n\;=\;{\alpha}_{n}f(x_n)+(1-\alpha_n)x_n$, $n\;{\geq}\;0$, $x_{n+1}=(1-{\beta}_n)y_n+{\beta}_nTy_n$, $n\;{\geq}\;0$, (0.4) converges strongly to a point p $\in$ Fix(T} which satisfies the variational inequality

    $\leq$ 0, z $\in$ Fix(T). (0.5) This result improves and extends the corresponding results of Yao et al[Y.Yao, H. Zhou, Y. C. Liou, Strong convergence of a modified Krasnoselski-Mann iterative algorithm for non-expansive mappings, J Appl Math Com-put (2009)29:383-389.

난류 혼합층에서 확산화염에 대한 flame hole dynamics 모델 (Flame Hole Dynamics Model of a Diffusion Flame in Turbulent Mixing Layer)

  • 김준홍;정석호;안국영;김종수
    • 한국연소학회지
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    • 제8권3호
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    • pp.15-23
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    • 2003
  • Partial quenching structure of turbulent diffusion flames in a turbulent mixing layer is investigated by the method of flame hole dynamics in order to develop a prediction model for turbulent flame lift off. The essence of flame hole dynamics is derivation of the random walk mapping, from the flame-edge theory, which governs expansion or contraction of flame holes initially created by local quenching events. The numerical simulation for flame hole dynamics is carried out in two stages. First, a direct numerical simulation is performed for constant-density fuel-air channel mixing layer to obtain the turbulent flow and mixing fields, from which a time series of two dimensional scalar dissipation rate array is extracted at a fixed virtual flame surface horizontally extending from the end of split plate to the downstream. Then, the Lagrangian simulation of the flame hole random walk mapping projected to the scalar dissipation rate array yields temporally evolving turbulent extinction process and its statistics on partial quenching characteristics. The statistical results exhibit that the chance of partial quenching is strongly influenced by the crossover scalar dissipation rate while almost unaffected by the iteration number of the mapping that can be regarded as a flame-edge speed.

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A GENERAL ITERATIVE ALGORITHM FOR A FINITE FAMILY OF NONEXPANSIVE MAPPINGS IN A HILBERT SPACE

  • Thianwan, Sornsak
    • Journal of applied mathematics & informatics
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    • 제28권1_2호
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    • pp.13-30
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    • 2010
  • Let C be a nonempty closed convex subset of a real Hilbert space H. Consider the following iterative algorithm given by $x_0\;{\in}\;C$ arbitrarily chosen, $x_{n+1}\;=\;{\alpha}_n{\gamma}f(W_nx_n)+{\beta}_nx_n+((1-{\beta}_n)I-{\alpha}_nA)W_nP_C(I-s_nB)x_n$, ${\forall}_n\;{\geq}\;0$, where $\gamma$ > 0, B : C $\rightarrow$ H is a $\beta$-inverse-strongly monotone mapping, f is a contraction of H into itself with a coefficient $\alpha$ (0 < $\alpha$ < 1), $P_C$ is a projection of H onto C, A is a strongly positive linear bounded operator on H and $W_n$ is the W-mapping generated by a finite family of nonexpansive mappings $T_1$, $T_2$, ${\ldots}$, $T_N$ and {$\lambda_{n,1}$}, {$\lambda_{n,2}$}, ${\ldots}$, {$\lambda_{n,N}$}. Nonexpansivity of each $T_i$ ensures the nonexpansivity of $W_n$. We prove that the sequence {$x_n$} generated by the above iterative algorithm converges strongly to a common fixed point $q\;{\in}\;F$ := $\bigcap^N_{i=1}F(T_i)\;\bigcap\;VI(C,\;B)$ which solves the variational inequality $\langle({\gamma}f\;-\;A)q,\;p\;-\;q{\rangle}\;{\leq}\;0$ for all $p\;{\in}\;F$. Using this result, we consider the problem of finding a common fixed point of a finite family of nonexpansive mappings and a strictly pseudocontractive mapping and the problem of finding a common element of the set of common fixed points of a finite family of nonexpansive mappings and the set of zeros of an inverse-strongly monotone mapping. The results obtained in this paper extend and improve the several recent results in this area.

MC-CDMA 시스템에서 실수 고정점 반복 기반의 전치왜곡기를 이용한 비선형 왜곡 보상 (Compensation of Nonlinear Distortion Using a Predistorter Based on Real-Valued Fixed Point Iterations in MC-CDMA Systems)

  • 전재현;신요안;임성빈
    • 대한전자공학회논문지TC
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    • 제37권1호
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    • pp.1-11
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    • 2000
  • 본 논문에서는 다중 반송파 부호 분할 다원 접속 (multi-carrier-code division multiple access; MC-CDMA) 시스템 내의 고출력 증폭기에 의해 발생하는 비선형 왜곡의 보상을 위한 전치왜곡기를 제안한다. 제안된 방법은 contraction mapping 정리와 이에 따른 고정점 반복에 기반하고 있다. 우리가 이미 다른 논문에서 제안하였던 고정점 반복 기반의 전치왜곡기가 복소수 변조 신호 자체에 적용되는 것에 반해, 여기서 제안하는 전치왜곡기는 변조 신호의 진폭에 고정점 반복을 적용하여 실수 연산을 수행하므로써 계산량을 감소시킨다. 송신기에서 traveling wave tube amplifier를 고출력 증폭기로 사용하고, BPSK 변조와 64개의 부반송파를 이용하는 동기식 MC-CDMA 기저대역 시스템에 대한 컴퓨터 시뮬레이션 결과, 제안된 전치왜곡기를 사용하는 경우 그렇지 않은 경우에 비해 비트오율 및 total degradation의 측면에서 월등한 성능 향상이 가능함을 알 수 있었다. 또한, 작은 output back-off 레벨에 대해 제안된 전치왜곡기는 복소수 연산을 수행하는 기존의 공점점 반복 기반의 전치왜곡기보다 우수한 성능을 보임을 역시 확인하였다.

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비선형 해양파의 파형 연구에 관하여 (A Study on Nonlinear Water-Wave Profile)

  • 장택수;황성현;권순홍
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.179-182
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    • 2004
  • This paper deals with a new mathematical formulation of nonlinear wave profile based on Banach fixed point theorem. As application of the formulation and its solution procedure, some numerical solutions was presented in this paper and nonlinear equation was derived. Also we introduce a new operator for iteration and getting solution. A numerical study was accomplished with Stokes' first-order solution and iteration scheme, and then we can know the nonlinear characteristic of Stokes' high-order solution. That is, using only Stokes' first-oder(linear) velocity potential and an initial guess of wave profile, it is possible to realize the corresponding high-oder Stokian wave profile with tile new numerical scheme which is the method of iteration. We proved the mathematical convergence of tile proposed scheme. The nonlinear strategy of iterations has very fast convergence rate, that is, only about 6-10 iterations arc required to obtain a numerically converged solution.

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교근에서 보툴리눔 독소 주사점의 표지화 (Surface Mapping of Masseter for Botulinum Toxin Injection)

  • 김준형;이민재;김현지;손대구;한기환;이소영;임정근;최인장
    • Archives of Plastic Surgery
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    • 제32권3호
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    • pp.311-313
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    • 2005
  • Generally, many Asian women tend to dislike the square jaw, as they believe it makes the face look wider, giving a stubborn and strong impression. Contouring of the mandible is therefore a relatively common aesthetic procedure among Asians. These days, the use of botulinum toxin for contouring of the lower face offer simple alternative to surgery. Motor point, which is the site over a muscle where its contraction may be elicited by a minimal intensity short duration electrical stimulus, is the optimal injection point of botulinum toxin. Study was undertaken to identify the location of motor point of the masseter muscle and the skin surface landmark. First, the thickest point of the masseter muscle was inspected through palpation and inspection by 3 different individual plastic surgeons and then compound muscle action potentials(CMAPs) of masseter muscle in 15 health volunteers were recorded using EMG. For the localization of the measured points, line between lateral canthus to the mandibular angle was used. Location of motor points were mapped to skin surface from lateral canthus in a percentage of the distance along the landmark line and in distance in millimeters. The clinical injection point was located at 71.69 percentile and 7.3 mm of the landmark line. The motor point test was located at 72.54 percentile and 7.1 mm of the landmark line. The depth of motor point was 16mm. There was no statistically significant difference between the clinical injection point and the motor point. We conclude that surface mapping of motor point of the masseter muscle would increase accessibility and accuracy in botulinum toxin injection for contouring of the lower face.

출력제어기를 이용한 불학실 파라미터를 갖는 로봇의 위치제어 (Position control of robots with uncertain parameters using output-feedback controller)

  • 최은석;윤재석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.472-475
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    • 1997
  • The principle objective of this paper is to explain and demonstrate the advantage of the output-feedback controller proposed by Ailon in [61 by using simulation and experimental results. Namely, the goal of this study is to design and implement a real-time controller for set-point regulation of a one-link rigid robot manipulator with unknown parameters using only position measurement. For implementation a direct drive one-link rigid robot manipulator is constructed and a TMS320C40 DSP systems board is used in implementing real-time control algorithm.

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