Search results for " Fixed"
showing 10 items of 248 documents
Set-valued mappings in partially ordered fuzzy metric spaces
2014
Abstract In this paper, we provide coincidence point and fixed point theorems satisfying an implicit relation, which extends and generalizes the result of Gregori and Sapena, for set-valued mappings in complete partially ordered fuzzy metric spaces. Also we prove a fixed point theorem for set-valued mappings on complete partially ordered fuzzy metric spaces which generalizes results of Mihet and Tirado. MSC:54E40, 54E35, 54H25.
Guaranteed and computable error bounds for approximations constructed by an iterative decoupling of the Biot problem
2021
The paper is concerned with guaranteed a posteriori error estimates for a class of evolutionary problems related to poroelastic media governed by the quasi-static linear Biot equations. The system is decoupled by employing the fixed-stress split scheme, which leads to an iteratively solved semi-discrete system. The error bounds are derived by combining a posteriori estimates for contractive mappings with functional type error control for elliptic partial differential equations. The estimates are applicable to any approximation in the admissible functional space and are independent of the discretization method. They are fully computable, do not contain mesh-dependent constants, and provide r…
Semi-strong inefficiency in the fixed odds betting market: Underestimating the positive impact of head coach replacement in the main European soccer …
2019
Abstract In this paper we analyse the efficiency of the sports betting market, seeking to ascertain whether the market is efficient in the case of fixed odds provided by bookmakers in the four major European soccer leagues under the semi-strong efficiency hypothesis. By examining the trends of odds in the event of a major change in expectations about team results, i.e. when the head coach of a team is replaced, we attempt to verify the argument that a profitable strategy for the bettor is likely to be possible. In this case, the market under consideration would be inefficient. Analysing the average effect of head coach replacement, we find a positive impact on team performance. Based on thi…
Nonlinear analysis of cylindrical and conical hysteretic whirl motions in rotor-dynamics
2014
Abstract The internal friction of a rotor–shaft-support system is mainly due to the shaft structural hysteresis and to some possible shrink-fit release of the assembly. The experimentation points out the destabilizing effect of the internal friction in the over-critical rotor running. Nevertheless, this detrimental influence may be efficiently counterbalanced by other external dissipative sources located in the supports or by a proper anisotropic configuration of the support stiffness. The present analysis considers a rotor–shaft system which is symmetric with respect to the mid-span and is constrained by viscous-flexible supports with different stiffness on two orthogonal planes. The cylin…
A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors
2017
The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability ev…
LABA/LAMA fixed-dose combinations in patients with COPD: A systematic review
2018
Paola Rogliani,1 Luigino Calzetta,1 Fulvio Braido,2 Mario Cazzola,1 Enrico Clini,3 Girolamo Pelaia,4 Andrea Rossi,5 Nicola Scichilone,6 Fabiano Di Marco7 1Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy; 2Department of Internal Medicine, IRCCS San Martino Genoa University Hospital, Genoa, Italy; 3Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy; 4Department of Medical and Surgical Sciences, Section of Respiratory Diseases, Magna Græcia University, Catanzaro, Italy; 5Pulmonary Unit, University of Verona, Verona, Italy; 6Department of Internal Medicine, University of Palermo, Palermo, Italy; 7…
Bifurcation analysis of a TaO memristor model
2019
This paper presents a study of bifurcation in the time-averaged dynamics of TaO memristors driven by narrow pulses of alternating polarities. The analysis, based on a physics-inspired model, focuses on the stable fixed points and on how these are affected by the pulse parameters. Our main finding is the identification of a driving regime when two stable fixed points exist simultaneously. To the best of our knowledge, such bistability is identified in a single memristor for the first time. This result can be readily tested experimentally, and is expected to be useful in future memristor circuit designs.
Optical Imaging of Coherent Molecular Rotors
2020
International audience; Short laser pulses are widely used for controlling molecular rotational degrees of freedom and inducing molecular alignment, orientation, unidirectional rotation and other types of coherent rotational motion. To follow the ultra-fast rotational dynamics in real time, several techniques for producing molecular movies have been proposed based on the Coulomb explosion of rotating molecules, or recovering molecular orientation from the angular distribution of high-harmonics. The present work offers and demonstrates a novel non-destructive optical method for direct visualization and recording of movies of coherent rotational dynamics in a molecular gas. The technique is b…
Monitoring and Market Power in Loan Markets
2000
Whether or not banks are engaged in ex ante monitoring of customers may have important consequences for the whole economy. We approach this question via a model in which banks can invest in either information acquisition or market power (product differentiation). The two alternatives generate different predictions, which are tested using panel data on Finnish local banks. We find evidence that banks’ investments in branch networks and human capital (personnel) contribute to information acquisition but not to market power. We also find that managing customers’ money transactions enhances banks ability to control their lending risks.
Fixed point theorems for $\alpha$-$\psi$-contractive type mappings
2012
In this paper, we introduce a new concept of $\alpha$-$\psi$-contractive type mappings and establish fixed point theorems for such mappings in complete metric spaces. Starting from the Banach contraction principle, the presented theorems extend, generalize and improve many existing results in the literature. Moreover, some examples and applications to ordinary differential equations are given here to illustrate the usability of the obtained results.