Search results for " proximity."
showing 10 items of 72 documents
Best Proximity Points for Some Classes of Proximal Contractions
2013
Given a self-mapping g: A → A and a non-self-mapping T: A → B, the aim of this work is to provide sufficient conditions for the existence of a unique point x ∈ A, called g-best proximity point, which satisfies d g x, T x = d A, B. In so doing, we provide a useful answer for the resolution of the nonlinear programming problem of globally minimizing the real valued function x → d g x, T x, thereby getting an optimal approximate solution to the equation T x = g x. An iterative algorithm is also presented to compute a solution of such problems. Our results generalize a result due to Rhoades (2001) and hence such results provide an extension of Banach's contraction principle to the case of non-s…
Fixed Costs Per Shipment
2011
Exporting firms do not only decide how much of their products they ship abroad but also at which frequency. Doing so, they face a trade-off between saving on fixed costs per shipments (by shipping large amounts infrequently) and saving on storage costs (by delivering just in time with small and frequent shipments). The firm's optimal choice defines a mapping from size and frequency of shipments to fixed costs per shipment. We use a unique dataset of Swiss cross-border trade on the transaction level to analyze the size and shape of the underlying fixed costs. The data suggest that for the average Swiss exporter the fixed costs per shipment are economically important: 0.82 percent of the valu…
Recess photomask contact lithography and the fabrication of coupled silicon photonic and plasmonic waveguide switches
2015
Display Omitted A lithography technique capable of printing submicron-sized features inside deep cavities is presented.A so-called recess photomask adapted to the wafer's topography is employed.Based on a standard mask aligner, Recess Photomask Contact Lithography has moderate cost.Its efficiency for a photonic/plasmonic switch application was demonstrated experimentally.The technique is extensible to any design and to wafers with multiple level recesses. A novel lithographic method is presented, based on the use of a mask aligner in the contact mode with a modified photomask, the so-called recess photomask; its goal is the printing of submicron-sized patterns into deep cavities of a chip, …
Development of procedures for programmable proximity aperture lithography
2013
Abstract Programmable proximity aperture lithography (PPAL) with MeV ions has been used in Jyvaskyla and Chiang Mai universities for a number of years. Here we describe a number of innovations and procedures that have been incorporated into the LabView-based software. The basic operation involves the coordination of the beam blanker and five motor-actuated translators with high accuracy, close to the minimum step size with proper anti-collision algorithms. By using special approaches, such writing calibration patterns, linearisation of position and careful backlash correction the absolute accuracy of the aperture size and position, can be improved beyond the standard afforded by the repeata…
Cultural institutions as agents of urban and community regeneration in the (post-)pandemic city. The case of the «Laboratorio Zen Insieme» in Palermo
2022
Although all cities in the world have been affected by the COVID-19 pandemic, its impacts on the territories, yet to be understood, are unevenly distributed, revealing extremely varied imbalances depending on the places. However, it is clear that the virus and its variants have aggravated pre-existing socio-spatial inequalities, creating new ones and bringing attention back to those implications between space, planning, public health and citizenship that are at the origins of contemporary urbanism. In a reference framework in which the crisis is globalized but unequal and in the absence of a welfare system capable of responding to the urgencies of the most marginalized social contexts and g…
Can Interactive Mediation Tools Bridge the Identity Gap Between the Public and the Art Museum?
2015
International audience; Consumer behaviour in the field of art museums appears to be influenced both by the identity of the public and the art museum and by the context. It is a matter not of changing museum content, but of bringing its identity closer to that of the public in order to promote access to art. The authors first present the theoretical and conceptual framework for their research and then suggest a qualitative methodological approach to addressing the issues described in the results.; La conducta del consumidor en los museos de arte parece estar influenciada tanto por la identidad del público y del museo como por el contexto. No se trata de cambiar el contenido del museo, pero …
phi-Best proximity point theorems and applications to variational inequality problems
2017
The main concern of this study is to introduce the notion of $$\varphi $$ -best proximity points and establish the existence and uniqueness of $$\varphi $$ -best proximity point for non-self mappings satisfying $$(F,\varphi )$$ -proximal and $$(F,\varphi )$$ -weak proximal contraction conditions in the context of complete metric spaces. Some examples are supplied to support the usability of our results. As applications of the obtained results, some new best proximity point results in partial metric spaces are presented. Furthermore, sufficient conditions to ensure the existence of a unique solution for a variational inequality problem are also discussed.
Best proximity points for cyclic Meir–Keeler contractions
2008
Abstract We introduce a notion of cyclic Meir–Keeler contractions and prove a theorem which assures the existence and uniqueness of a best proximity point for cyclic Meir–Keeler contractions. This theorem is a generalization of a recent result due to Eldred and Veeramani.
Best proximity point results for modified α-proximal C-contraction mappings
2014
First we introduce new concepts of contraction mappings, then we establish certain best proximity point theorems for such kind of mappings in metric spaces. Finally, as consequences of these results, we deduce best proximity point theorems in metric spaces endowed with a graph and in partially ordered metric spaces. Moreover, we present an example and some fixed point results to illustrate the usability of the obtained theorems. MSC:46N40, 46T99, 47H10, 54H25.
Cyclic (noncyclic) phi-condensing operator and its application to a system of differential equations
2019
We establish a best proximity pair theorem for noncyclic φ-condensing operators in strictly convex Banach spaces by using a measure of noncompactness. We also obtain a counterpart result for cyclic φ-condensing operators in Banach spaces to guarantee the existence of best proximity points, and so, an extension of Darbo’s fixed point theorem will be concluded. As an application of our results, we study the existence of a global optimal solution for a system of ordinary differential equations.