Search results for " Direct"
showing 10 items of 943 documents
Laser direct writing of gold conductors from metallorganic inks
1993
Laser deposition of gold lines from spin-on metallorganic (MO) precursors has been studied. A readily available and relatively low-cost commercial MO ink has been used to write gold interconnects on different substrates. The physical properties of the ink, its laser-firing process on oxidised silicon substrates and its electrical characterisation are presented here, together with the experimental procedure needed for obtaining low-resistivity deposits.
The Effect of Building Direction on Microstructure and Microhardness during Selective Laser Melting of Ti6Al4V Titanium Alloy
2021
AbstractDuring the last few years, additive manufacturing has been more and more extensively used in several industries, especially in the aerospace and medical device fields, to produce Ti6Al4V titanium alloy parts. During the Selective Laser Melting (SLM) process, the heterogeneity of finished product is strictly connected to the scan strategies and the building direction. An optimal managing of the latter parameters allows to better control and defines the final mechanical and metallurgical properties of parts. Acting on the building direction it is also possible to optimize the critical support structure. In particular, more support structures are needed for the sample at 0°, while very…
Thermo-optic control of dielectric-loaded plasmonic Mach-Zehnder interferometers and directional coupler switches
2012
We report detailed experimental studies of compact fiber-coupled dielectric-loaded plasmonic waveguide components-Mach-Zehnder interferometers (MZIs) and directional couplers (DCs)-whose operation at telecom wavelengths is controlled via the thermo-optic effect by electrically heating the gold stripe of dielectric-loaded plasmonic waveguides. The effect of the gaps isolating the heated part of the waveguide from the rest of the structure was examined showing the presence of a Fabry-Perot cavity in this MZI arm. Wavelength-dependent modulation is demonstrated with MZI-based components, and wavelength dependent low power (similar to 0.92 mW) rerouting is achieved with DC switches. Furthermore…
Analysis of multipactor RF breakdown in a waveguide containing a transversely magnetized ferrite
2016
In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3-D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap
An exact algorithm for the min-cost network containment problem
2004
A network design problem which arises in the distribution of a public utility provided by several competitive suppliers is studied. The problem addressed is that of determining minimum-cost (generalized) arc capacities in order to accommodate any demand between given source–sink pairs of nodes, where demands are assumed to fall within predetermined ranges. Feasible flows are initially considered as simply bounded by the usual arc capacity constraints. Then, more general linear constraints are introduced which may limit the weighted sum of the flows on some subsets of arcs. An exact cutting plane algorithm is presented for solving both of the above cases and some computational results are re…
A New Min-Max Optimisation Approach for Fast Learning Convergence of Feed-Forward Neural Networks
1993
One of the most critical aspect for a wide use of neural networks to real world problems is related to the learning process which is known to be computational expensive and time consuming.
Robust estimation of partial directed coherence by the vector optimal parameter search algorithm
2009
We propose a method for the accurate estimation of Partial Directed Coherence (PDC) from multichannel time series. The method is based on multivariate vector autoregressive (MVAR) model identification performed through the recently proposed Vector Optimal Parameter Search (VOPS) algorithm. Using Monte Carlo simulations generated by different MVAR models, the proposed VOPS algorithm is compared with the traditional Vector Least Squares (VLS) identification method. We show that the VOPS provides more accurate PDC estimates than the VLS (either overall and single-arc errors) in presence of interactions with long delays and missing terms, and for noisy multichannel time series. ©2009 IEEE.
An exact algorithm for the solution of a network design problem
2004
Gli aspetti fiscali delle attività di rigenerazione e riuso di beni a fini di interesse generale.
2017
E’ possibile attribuire un riconoscimento, una legittimazione ed una regolamentazione giuridica all'opera prestata dai privati nell'attività di rigenerazione e riuso di beni di interesse comune? La leva fiscale può essere considerata come strumento per favorire lo sviluppo di queste attività? Alla prima domanda possiamo rispondere che il concetto, oggi in evoluzione, di sussidiarietà orizzontale, sembra essere lo strumento più idoneo per inquadrare giuridicamente le azioni di privati cittadini che volontariamente decidono di prendersi cura di beni comuni ai più diversi livelli (beni immobili o mobili concernenti il patrimonio artistico/culturale o, più in generale, fruibili da una collettiv…