106,043 research outputs found
Common fixed points of generalized contractions on partial metric spaces and an application
No full textIn this paper, common fixed point theorems for four mappings satisfying a generalized nonlinear contraction type condition on partial metric spaces are proved. Presented theorems extend the very recent results of I. Altun, F. Sola and H. Simsek [Generalized contractions on partial metric spaces, Topology and its applications 157 (18) (2010) 2778–2785]. As application, some homotopy results for operators on a set endowed with a partial metric are given
Cyclic admissible contraction and applications to functional equations in dynamic programming
No full textIn this paper, we introduce the notion of T-cyclic (alpha,beta)-contraction and give some common fixed point results for this type of contractions. The presented theorems extend, generalize, and improve many existing results in the literature. Several examples and applications to functional equations arising in dynamic programming are also given in order to illustrate the effectiveness of the obtained results
A fixed point theorem for a Meir-Keeler type contraction through rational expression
No full textIn this paper, we establish a new fixed point theorem for a Meir-Keeler type contraction through rational expression. The presented theorem is an extension of the result of Dass and Gupta (1975). Some applications to contractions of integral type are given
Coupled fixed point results in cone metric spaces for w-compatible mappings
No full textIn this paper, we introduce the concepts of w-compatible mappings, b-coupled coincidence point and b-common coupled fixed point for mappings F,G : X x X -> X, where (X, d) is a cone metric space. We establish b-coupled coincidence and b-common coupled fixed point theorems in such spaces. The presented theorems generalize and extend several well-known comparable results in the literature, in particular the recent results of Abbas et al. [Appl. Math. Comput. 217, 195-202 (2010)]. Some examples are given to illustrate our obtained results. An application to the study of existence of solutions for a system of non-linear integral equations is also considered
Nonlinear contractions involving simulation functions in a metric space with a partial order
No full textVery recently, Khojasteh, Shukla and Radenovic [F. Khojasteh, S. Shukla, S. Radenovic, Filomat, 29 (2015), 1189-1194] introduced the notion of Z-contraction, that is, a nonlinear contraction involving a new class of mappings namely simulation functions. This kind of contractions generalizes the Banach contraction and unifies several known types of nonlinear contractions. In this paper, we consider a pair of nonlinear operators satisfying a nonlinear contraction involving a simulation function in a metric space endowed with a partial order. For this pair of operators, we establish coincidence and common fixed point results. As applications, several related results in fixed point theory in a metric space with a partial order are deduced
Synthesis, structure and bioactivity of a mononuclear octahedral [Prolinate2-Na(MeOH)4]−H+ complex
No full textThe synthesis of a mononuclear octahedral [Prolinate2-Na(MeOH)4]−H+ complex is achieved from a [3 + 2] cycloadduct with excess of NaOMe in methanol. The slow crystallization provides the hexacoordinated complex stabilized by four molecules of solvent. The antibacterial, antifungal and anti-tuberculosis activity of this compound is also evaluated.This work is a part of Samet Belveren's ongoing PhD thesis granted by Mersin University (Project no. BAP-SBE TEB(SB) 2017-2-TP3-2564). We gratefully acknowledge financial support from Mersin University and the Spanish Ministerio de Economía y Competitividad (MINECO) (projects CTQ2013-43446-P and CTQ2014-51912-REDC), the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER, EU) (projects CTQ2016-76782-P and CTQ2016-81797-REDC), the Generalitat Valenciana (PROMETEOII/2014/017), University of Alicante and Mersin University (Project. MEU-2017-COL-01007-M150D)
Uzay-zaman kafes kodlamalı MIMO-OFDM sistemlerinin başarım analizi
No full textThe space-time trellis coded orthogonal frequency division multiplexing (STTC-OFDM) has been implemented with the conventional maximum-likelihood decoder for multiple antenna transmission since the STTC-OFDM was initially proposed. In this paper, a modified maximum-likelihood decoding method with the utilization of a multiplexer at the transmitter and a demultiplexer at the receiver to isolate each transmitted signal at the corresponding receiver is presented. With this modified approach, the STTC-OFDM gives a better frame error rate (FER) performance than the traditional one over the Rayleigh frequency selective fading channels. The Doppler impact is additionally considered for the aggregate system to contrast the proposed methodology and the existing STTC-OFDM systems. Simulation results show that the modified STTC-OFDM framework enhances the FER performance by almost 4 dB at the FER value of 10-2 where the Doppler frequency equals to zero at the receiver. Even if a Doppler frequency exists in the system, the proposed scheme still gives a better performance than the existing STTC-OFDM systems
Space–time trellis-coded ofdm systems in frequency-selective mobile fading channels
No full textDue to copyright restrictions, the access to the full text of this article is only available via subscription.Space-time trellis code (STTC) techniques provide both coding gain and diversity gain to orthogonal frequency-division multiplexing (OFDM) systems without reducing bandwidth efficiency. However, factors such as residual carrier frequency offset due to Doppler shift destroy the orthogonality among subcarriers, which results in intercarrier interference (ICI) in mobile fading channels and bit error rate (BER) degradation. This brief presents three STTC-based OFDM systems to improve BER in frequency-selective mobile fading channels. First, a new STTC-ST method is developed with OFDM to form a new STTC-ST-OFDM system. Second, a Walsh-Hadamard (WH) transform is employed as a precoder to form a new STTC-WH-ST-OFDM system with limited growing computation. Third, the STTC-WH-ST-OFDM system is integrated with an ST conjugate cancelation (CC) scheme to form an STTC-WH-STCC-OFDM transceiver with expanding bandwidth in order to combat ICI. Simulations indicate that the STTC-WH-STCC-OFDM system outperforms both STTC-WH-ST-OFDM and STTC-ST-OFDM systems, whereas the STTC-WH-ST-OFDM system outperforms the STTC-ST-OFDM system. All three schemes are simple and are backward compatible with existing OFDM systems. They can serve as baseband building blocks for multiuser OFDM systems, specifically in downlink networks
- …
