oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 198 )

2018 ( 272 )

2017 ( 290 )

Custom range...

Search Results: 1 - 10 of 204135 matches for " G. Del Re "
All listed articles are free for downloading (OA Articles)
Page 1 /204135
Display every page Item
A Novel Manufacturing Technology for RF MEMS Devices on Ceramic Substrates
V. Schirosi,G. Del Re,L. Ferrari,P. Caliandro,L. Rizzi,G. Melone
Journal of Sensors , 2010, DOI: 10.1155/2010/625325
Abstract: Microelectromechanical systems are often used for their enormous capability and good qualities in T/R modules especially for space modular applications. High isolation and very low insertion loss are guaranteed by their intrinsic working principle. This is a very robust, flexible, and low-cost technology, and it provides high reliability, good reproducibility, and complete fulfillment of technical requirements. 1. Introduction The exploitation of MEMS technology for RF applications enables the manufacturing of high-performance and low-cost lumped components like variable capacitors, inductors, and switches. Starting from these elements, the implementation in MEMS technology of complete subnetworks to be integrated within RF and microwave functional blocks (e.g., RF transceivers) leads to a wider reconfigurability and, consequently, operability of the whole system. So, RF MEMS technology provides advanced solutions to fabricate very interesting devices for switching of radio frequency signals. This technology allows for reducing drastically device dimensions and number of connections, to operate with signal in large bandwidth, from 0 to 50?GHz, with consistent performances. MEMS devices, in fact, have been identified as a promising enabling technology thanks to their extremely reduced dimensions, their high isolation in open-circuit state, and low insertion loss in short-circuit state, the high linearity. Also, monolithic integration of MEMS devices with transmission lines on substrates with high dielectric constant such as ceramic substrates (aluminum oxide, aluminum nitride, LTCC, etc.) allows manufacturing of complex devices (phase shifters, power dividers, tunable filters, couplers, reconfigurable antennas, etc.) for phase and amplitude modulation which are essential components of TX/RX modules [1, 2]. 2. RF MEMS Design The RF MEMS devices described have been full designed, fabricated, and tested at Microelectronic Research Lab of Optel Consortium. Design is carried out by electromechanical and electromagnetic simulation of RF MEMS. Electromechanical design consists of an FEM modeling of micromechanic structures. The goal of the design is the optimization of parameters such as switching time, overshoot, and pull-in voltage. FEM simulations provide an actuation time of 10–15?μsec, an overshoot less than 13% of the gap and a pull-in voltage of 15?V [3–5]. Electromagnetic design consists of full-wave simulations that provide parameter curves of the device [6, 7]. For a shunt switch, in OFF state, return loss is better than ?25?dB and insertion loss is
Tiempo del trabajo asalariado y tiempodel trabajo de reproducción
ALISA del Re
Política y Sociedad , 1995, DOI: -
Abstract: Sin resumen
Models and analogies in science
Giuseppe Del Re
Hyle : International Journal for Philosophy of Chemistry , 2000,
Abstract: Science makes extensive use of models, i.e. simplified or idealized representations of the systems found in the physical world. Models fall into at least two categories: mathematical and physical models. In this paper, we focus attention mainly on the latter, trying to show that they are essential tools not only of the scientific description of the world 'out there', but of man's cognition of things, especially things not directly accessible to the senses. The spring-and-ball (SB) model of chemistry is a most instructive example of a physical model. In other disciplines, from cosmology to physiology, models are used that are of the same kind or play the same role. It is concluded that physical models are objects which belong to the world accessible to man's direct experience, often constructed ad hoc and possibly idealized. They serve as referents for analogies, which appear to be indispensable in most aspects of scientific theorizing, especially for the understanding of the submicroscopic levels of reality.
Bensaude-Vincent, Bernadette and Bruno Bernardi (eds.): "Jean-Jacques Rousseau et la chimie" (Paris 1999) (book review)
Giuseppe Del Re
Hyle : International Journal for Philosophy of Chemistry , 2001,
Abstract: book review of Bensaude-Vincent, Bernadette and Bruno Bernardi (eds.): "Jean-Jacques Rousseau et la chimie" (Paris 1999)
Ontological Status of Molecular Structure
Giuseppe Del Re
Hyle : International Journal for Philosophy of Chemistry , 1998,
Abstract: Molecular structure (MS) has been treated as a convention or an epiphenomenon by physicists and quantum chemists interpreting the mathematical formalism of quantum mechanics as the essential reality criterion in the submicroscopic world (R2 world). This paper argues that, (a) even in the R2 world there is a class of entities which are real per se, even though they cannot be separated from their material support, and MS may belong to that class; (b) MS actualizes a particular molecule from the many potentialities of a given set of nuclei and electrons, all present in the same Schroedinger equation; (c) MS is a fact established in the XIXth century, albeit as a result of circumstantial evidence (because of its belonging to the R2 world); (d) the fact that MS is known, as all objects of the atomic world, in terms of analogies with macroscopic models, is not valid grounds for questioning its reality; (e) MS is a set of topological as well as geometrical relations. All along the discussion, observability according to Bohr, Heisenberg, Feynman is taken as the essential criterion of reality in the R2 world. On its basis, quantum mechanics is by no means in conflict with the reality of molecular structure and shape. On the other hand, the question of the minimum lifetime required for a MS proper to exist should be left open, pending a detailed analysis of measurement techniques.
Technology and the Spirit of Alchemy
Giuseppe Del Re
Hyle : International Journal for Philosophy of Chemistry , 1997,
Abstract: A historical perspective can throw light on problematic aspects of technology, regarded as part of the scientific approach to Nature. The master reference in this respect is chemistry, a science which still gives priority, as its mother alchemy, to the practical imitation and emulation of Nature's most secret operations. Now, the transition from the fogs of alchemy to the rigor of chemistry is often attributed to the abandonment of the religious foundations of the alchemical 'philosophy'. In this paper, we argue that, on the contrary, the complete elimination of the 'spirit of alchemy' was an unjustified loss and a premise for the misuses of technology now seriously dreaded.
Ethics and Science
Giuseppe Del Re
Hyle : International Journal for Philosophy of Chemistry , 2001,
Abstract: Consideration of possible bearing of ethics on scientific activity as such - i.e. beside moral or legal conditions on applications of science and avoidance of frauds or superficiality - lead to the conclusion that scientists, particularly chemists, ought to ponder the choiceworthiness of every free action they undertake in the pursuit of scientific knowledge, for it may involve tampering with the harmonious evolution of nature and society, indeed with human beings themselves. It seems unavoidable that a decision should be based on the fundamental values of the tradition of mankind, expressed by the three Platonic values. Such a foundation, unfortunately, cannot show a way to eliminate all risks of wrong choices. Since, nevertheless, to contribute to the increase of knowledge is a professional and moral duty of a scientist; the latter is usually obliged to take a decision. He must be aware that his personal responsibility may be engaged.
Aeby Daghé, Sandrine, dir. Enseigner la langue et la littérature. Des dispositifs pour penser leur articulation
Ariane Brun del Re
Voix Plurielles , 2013,
Abstract: Aeby Daghé, Sandrine, dir. Enseigner la langue et la littérature. Des dispositifs pour penser leur articulation
Recent results on Vub, Vcb and Mixing from the BaBar Experiment
Daniele del Re
Physics , 2003,
Abstract: We present the measurements of the CKM matrix parameters Vub, Vcb and of the B mixing oscillation frequency with the BaBar experiment at the asymmetric B-factory PEPII. Data were collected in the years 2000-2002 and the total available statistics corresponds to 91 fb-1. The Vub, Vcb measurements utilize both inclusive and exclusive semileptonic decays of the $B$ meson. The Delta(md) parameter is measured by using the time evolution of the B, determined from the flight length difference between the two B mesons.
Energy Efficient Non-Cooperative Methods for Resource Allocation in Cognitive Radio Networks  [PDF]
Enrico Del Re, Renato Pucci, Luca Simone Ronga
Communications and Network (CN) , 2012, DOI: 10.4236/cn.2012.41001
Abstract: In a cognitive radio network wherein primary and secondary users coexist, an efficient power allocation method represents one of the most important key aspects. This paper provides a novel approach based on a game theory framework to solve this problem in a distributed and fair way. Formulated as an optimization problem, the resource allocation problem between secondary users and primary users can be modeled and investigated with the Game Theory, and in particular S-Modular Games, since they provide useful tools for the definition of multi objective distributed algorithms in the context of radio communications. This paper provides also a performance comparison among the proposed game and two other algorithms, frequently used in this context: Simulated Annealing and Water Filling.
Page 1 /204135
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.