2024-03-28T12:30:36Z
http://eprints.biblio.unitn.it/cgi/oai2
oai:eprints.biblio.unitn.it:895
2012-02-28T14:18:41Z
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Design and Performance Evaluation of MORA: a Movement-Based Routing Algorithm for Ad Hoc Networks
Boato, Giulia
Granelli, Fabrizio
Kliazovich, Dzmitry
TK7885 Computer Engineering
TK5105.5 Computer Networks
TA350 Applied Mechanics
TA329 Engineering mathematics
In an ad hoc environment with no wired communication infrastructure, mobile hosts necessarily operate as routers, in order to provide network connectivity. Since mobile ad hoc networks change their topology frequently and without prior notice, routing in such networks becomes a challenging task. To explicitly consider node movements, we present MORA, a movement-based routing algorithm for mobile ad hoc networks. The algorithm is completely distributed, since nodes need to communicate only with direct neighbors within their transmission range, and utilizes a specific metric, which exploits not only the position, but also the direction of movement of mobile hosts. Extensive simulations evaluating the proposed protocol and results of comparison with existing methods demonstrate that MORA can provide an efficient and robust routing strategy.
2005-11
Departmental Technical Report
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/895/1/DIT%2D05%2D069.pdf
Boato, Giulia and Granelli, Fabrizio and Kliazovich, Dzmitry (2005) Design and Performance Evaluation of MORA: a Movement-Based Routing Algorithm for Ad Hoc Networks. UNSPECIFIED. (Submitted)
http://eprints.biblio.unitn.it/895/
oai:eprints.biblio.unitn.it:1493
2012-02-28T14:22:06Z
7374617475733D756E707562
7375626A656374733D51:5143:5143373630
7375626A656374733D51:5143:5143363631
7375626A656374733D54:544B:544B37383835
7375626A656374733D54:5441:5441333530
7375626A656374733D51:5141:51413735
7375626A656374733D51:5141:5141303633
7375626A656374733D51:5143:5143303230
7375626A656374733D54:5441:5441333239
74797065733D746563687265706F7274
SVM-based Classification Approach for Synthetic-Impulse Microwave Imaging
Viani, Federico
Benedetti, Manuel
Donelli, Massimo
Lizzi, Leonardo
Cresp, A.
Aliferis, L.
Pichot, Christian
Massa, Andrea
QC760 Electromagnetism
QC661 Electromagnetic Theory
TK7885 Computer Engineering
TA350 Applied Mechanics
QA075 Electronic computers. Computer science
QA063 Problem solving
QC020 Mathematical Physics
TA329 Engineering mathematics
Surface-Penetratic Radar (SPR) is aimed at providing an image of the objects buried in an inaccessible host medium. Such a scenario generally occurs in many applications, ranging from to the search of objects in the subsoil [Schubert 2001] to through-wall imaging (TWI)[Ferries 1998]. In order to effectively reconstruct an accurate image of the investigation area, many methodologies based on x-rays, ultrasonics, eddy currents, or microwaves have been investigated. In such a framework, microwave imaging techniques are very promising since electromagnetic fields at centimeter wavelenghts can penetrate non-ideal conductor materials and are usually low power and relatively inexpensive. Recently, thanks to the development of effective ultrawideband (UWB) hardware, wideband microwave imaging systems have been proposed. Compared to single-frequency approaches, such systems allow to collect a wider amount of information, since the scattered field can be measured at different frequencies in the working bandwidth and/or in the time-domain. In order to take advantage of multi-frequency data, signal processing plays a key role. Different techniques combining pre-processing treatments and microwave imaging are currently used to construct an image of a scene [Daniels 2004]. In addition, time-reversal (TR) data processing has been recently employed in order to detect positions of the targets in a Synthetic-Impulse Microwave Imaging System (SIMIS) [Cresp 2008]. In such a framework and within the GALILEO 2008 project, the research units, ELEDIA @ Univ. Trento and LEAT @ Univ. Nice, are currently involved in the integration of a SVM-based classification approach in the SIMIS for the reconstruction of the position and the shape of targets. Such a report is focused on the description of problem geometry as well as of the specification of the SIMIS.
2008-04
Departmental Technical Report
NonPeerReviewed
application/pdf
http://eprints.biblio.unitn.it/1493/1/DISI%2D08%2D047.pdf
Viani, Federico and Benedetti, Manuel and Donelli, Massimo and Lizzi, Leonardo and Cresp, A. and Aliferis, L. and Pichot, Christian and Massa, Andrea (2008) SVM-based Classification Approach for Synthetic-Impulse Microwave Imaging. UNSPECIFIED. (Unpublished)
http://eprints.biblio.unitn.it/1493/
oai:eprints.biblio.unitn.it:4272
2014-05-22T14:48:26Z
7374617475733D707562
7375626A656374733D54:5441:5441333530
7375626A656374733D54:5441:5441363330
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The "Egg of Columbus" for Making the World’s Toughest
Fibres
Pugno, Nicola M.
TA174 Engineering Design
TA350 Applied Mechanics
TA630 Structural Engineering
In this letter we present the "Egg of Columbus" for making fibres with unprecedented toughness: a slider, in the simplest form just a knot, is introduced as frictional element to dissipate additional energy and thus demonstrating the existence of a previously "hidden" toughness. The proof of concept is experimentally realized making the world’s toughest fibre, increasing the toughness modulus of a commercial Endumax macroscopic fibre from 44 J/g up to 1070 J/g (and of a zylon microfiber from 20 J/g up to 1400 J/g). The ideal upperbound toughness is expected for graphene, with a theoretical value of 10^5 J/g. This new concept, able of maximizing (one fold increment) the structural robustness, could explain the mysterious abundance of knot formations, in spite of their incremental energy cost and topological difficulty, in biological evolved structures, such as DNA strands and proteins.
Public Library of Science
Buehler, Markus J.
2014-04-02
Article in journal
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/4272/1/225%2DPLOSONE14%2Dknots.pdf
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0093079
Pugno, Nicola M. (2014) The "Egg of Columbus" for Making the World’s Toughest Fibres. In «PLOS ONE», vol. 9, n. 4 San Francisco, CA (USA) : Public Library of Science, e93079-6 pp..
http://eprints.biblio.unitn.it/4272/
info:eu-repo/semantics/article
ARRAY(0xbb0ff670)
info:eu-repo/semantics/openAccess
oai:eprints.biblio.unitn.it:4442
2016-07-20T23:15:06Z
7374617475733D707562
7375626A656374733D54:5441:5441333530
7375626A656374733D54:5441:5441363330
74797065733D61727469636C656A6F75726E616C
Structural reinforcement and failure analysis in composite nanofibers of graphene oxide and gelatin
Panzavolta, Silvia
Bracci, Barbara
Gualandi, Chiara
Focarete, Maria Letizia
Treossi, Emanuele
Kouroupis-Agalou, Konstantinos
Rubini, Katia
Bosia, Federico
Brely, Lucas
Pugno, Nicola M.
Palermo, Vincenzo
Bigi, Adriana
TA350 Applied Mechanics
TA630 Structural Engineering
In this work we study the mechanical properties and failure mechanism of nano-composites of graphene oxide sheets embedded in polymeric systems, namely films and electro-spun nanofibers. In this last system, contrary to conventional bulk composites, the size of the nano-reinforcement (GO sheets) is comparable to the size of the nanofibers to be reinforced (≈ 200 nm). As polymeric matrix we use gelatin. We demonstrate that the high chemical affinity of the two materials hinders the renaturation of gelatin into collagen and causes a nearly ideal mixing in the GO–gelatin composite. Adding just 1% of GO (wt of GO with respect to gelatin ) we obtain an increase of Young’s modulus >50% and an increase of fracture stress >60%. We use numerical simulations to study the failure mechanism of the fibers. Calculations well agree with experimental data and show that, even if cracks start at GO sheet edges due to stress concentrations, crack propagation is hindered by the nonlinear behaviour of the matrix. Moreover, the presence of the GO sheets in continuous gelatin films improves the material stability to phosphate buffer solutions from 2 days to 2 weeks, making it a better material than gelatin for applications in biological environments.
Elsevier
2014-07-21
Article in journal
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/4442/1/1%2Ds2.0%2DS0008622314006782%2Dpostprint.pdf
http://www.sciencedirect.com/science/article/pii/S0008622314006782
Panzavolta, Silvia and Bracci, Barbara and Gualandi, Chiara and Focarete, Maria Letizia and Treossi, Emanuele and Kouroupis-Agalou, Konstantinos and Rubini, Katia and Bosia, Federico and Brely, Lucas and Pugno, Nicola M. and Palermo, Vincenzo and Bigi, Adriana (2014) Structural reinforcement and failure analysis in composite nanofibers of graphene oxide and gelatin. In «Carbon», vol. 78, Netherlands : Elsevier, pp. 566-577.
http://eprints.biblio.unitn.it/4442/
info:eu-repo/semantics/article
ARRAY(0xbb0f4a90)
info:eu-repo/semantics/embargoedAccess
oai:eprints.biblio.unitn.it:4443
2015-05-26T23:15:05Z
7374617475733D707562
7375626A656374733D54:5441:5441333530
7375626A656374733D54:5441:5441363330
74797065733D61727469636C656A6F75726E616C
Hierarchical multiple peeling simulations
Bosia, Federico
Colella, S.
Mattoli, Virgilio
Mazzolai, Barbara
Pugno, Nicola M.
TA350 Applied Mechanics
TA630 Structural Engineering
The phenomenon of the exceptional dry adhesion achieved by some natural biological materials has been widely investigated in recent years. In particular, the analysis of the terminal elements of gecko pads and their specific structure and topology has led to the development of bioinspired synthetic fibrillar adhesives, including mushroom-shaped tips. To model the expected adhesion and detachment behaviour of multiple contacts, only recently the last author has derived a theory of multiple peeling, extending the pioneering energy-based single peeling theory of Kendall, including large deformations and pre-stretching. In this contribution, we study the problem of the adhesion of single and multiple contacts using finite element analysis, with the aim of studying complex peeling geometries. Both non-hierarchical tape-like and hierarchical geometries are considered, and the adhesive properties are compared, showing a marked improvement in the latter case. Results are promising and the numerical approach can be exploited in future attempts to determine optimal configurations and improve the adhesion of artificial bioinspired structures.
The Royal Society of Chemistry
2014-05-27
Article in journal
PeerReviewed
application/pdf
http://eprints.biblio.unitn.it/4443/1/RSCADV14_hierarchicalmultiplepeeling.pdf
http://pubs.rsc.org/en/Content/ArticleLanding/2014/RA/C4RA03459G
Bosia, Federico and Colella, S. and Mattoli, Virgilio and Mazzolai, Barbara and Pugno, Nicola M. (2014) Hierarchical multiple peeling simulations. In «RSC Advances», vol. 4, n. 48 London, UK : The Royal Society of Chemistry, pp. 25447-25452.
http://eprints.biblio.unitn.it/4443/
info:eu-repo/semantics/article
ARRAY(0xbb0f4430)
info:eu-repo/semantics/embargoedAccess