Il prossimo incontro di \Piz^2@TV(+IAC) si terrà il 28 maggio, sempre
alle ore 13, presso il Dipartimento di Matematica di Roma Tor Vergata,
aula "Dal Passo", sarà animato da Peter Wolenski (Department of Mathematics
Louisiana State University): "Spiking models of synaptic behavior and
impulsive systems".
Abstract: We shall describe a model proposed in neuroscience to describe the
flow of neurotransmitters across a synapse. This takes the form of an
impulsive system, and we shall provide the nature of its solutions and the
need for graph completions to be included in the model. Approximation and
sampling results of more general impulsive systems will also be described.
martedì 26 maggio 2009
martedì 19 maggio 2009
21 maggio 2009: Swimming phenomenon: Modeling, micro motions and controllability (Alexander Khapalov)
Il prossimo incontro di \Piz^2@TV(+IAC) si terrà il 21 maggio, sempre alle ore 13, presso il Dipartimento di Matematica di Roma Tor Vergata, aula "Dal Passo", sarà animato da Alexander Khapalov (Department of Mathematics, Washington State University) e avrà come titolo: "Swimming phenomenon: Modeling, micro motions and controllability".
Abstract: We consider a simplified model of an abstract object, formed by several narrow rectangles, which propels itself in a fishlike or rowing fashion in a fluid. The results include a formula for ``small'' motions of this model with the purpose to apply it to the study of
its global controllability properties.
Abstract: We consider a simplified model of an abstract object, formed by several narrow rectangles, which propels itself in a fishlike or rowing fashion in a fluid. The results include a formula for ``small'' motions of this model with the purpose to apply it to the study ofits global controllability properties.
sabato 9 maggio 2009
14 maggio 2009: Proprietà geometriche di alcune transizioni di fase (Enrico Valdinoci)
Il prossimo incontro di \Piz^2@TV(+IAC) si terrà il 14 maggio, sempre alle ore 13, presso il Dipartimento di Matematica di Roma Tor Vergata, aula "Dal Passo", sarà animato da Enrico Valdinoci (Univ. Tor Vergata) e avrà come titolo: "Proprietà geometriche di alcune transizioni di fase".
Abstract: Discuteremo informalmente alcune motivazioni e alcuni risultati di rigidità riguardanti equazioni ellittiche che modellizzano transizioni di fase (con applicazioni a onde d'acqua e operatori frazionari). A seconda degli interventi del pubblico il discorso potrebbe prendere strade diverse....
mercoledì 29 aprile 2009
7 maggio 2009: Self-Organized Patterns in Bacterial Colonies (Masayasu Mimura)
Il prossimo incontro di \Piz^2@TV(+IAC) si terrà il 7 maggio, sempre alle ore 13, presso il Dipartimento di Matematica di Roma Tor Vergata, aula "Dal Passo", sarà animato da Masayasu Mimura (Meiji Institute for Advanced Study of Mathematical Sciences, Meiji Univesrsity) e avrà come titolo: "Self-Organized Patterns in Bacterial Colonies".
Over the past ten years, our understanding of how spatio-temporal patterns in far from equilibrium systems has been rather deepened. Collaborative research of experimental and theoretical works have discovered the mechanism how complex patterns were generated in biological systems. It is emphasized that genetics does not always reveal the occurrence of such patterns and even simple systems may generate regular as well as chaotic irregular patterns in a self-organized way. Budrene and Berg observed diverse complex colonial patterns of chemotactic bacteria of E.coli ([1],[2]) (the following is one of the patterns). The aim of this talk is to support that such patterns are generated in a self-organized way by using modeling approach.
Keywords: colonial pattern formation, chemotactic mobility, self-organization.
REFERENCES
[1] Budrene E. O and Berg, H. C.: Nature 349 pp.630~633, 1991
[2] Budrene E. O and Berg, H. C.: Nature 376 pp. 49~53, 1995
giovedì 16 aprile 2009
23 aprile 2009: EVOLUZIONE DI PILE DI SABBIA (Carlo Sinestrari)
Il prossimo incontro di \Piz^2@TV(+IAC) si terrà il 23 aprile, sempre alle ore 13, presso il Dipartimento di Matematica di Roma Tor Vergata, aula "Dal Passo", sarà animato da Carlo Sinestrari (Dipartimento di Matematica, Universita' degli Studi di Roma TOR VERGATA) e avrà come titolo "EVOLUZIONE DI PILE DI SABBIA".
sabato 28 marzo 2009
2 Aprile 2009: INFORMATION SPREADING IN EVOLVING NETWORKS (Andrea Clementi)
Il prossimo incontro di \Piz^2@TV(+IAC) si terrà il 2 aprile, sempre alle ore 13, presso il Dipartimento di Matematica di Roma Tor Vergata, aula "Dal Passo", sarà animato da Andrea Clementi (Dipartimento di Matematica, Universita' degli Studi di Roma TOR VERGATA) e avrà come titolo "INFORMATION SPREADING IN EVOLVING NETWORKS"
Summary: There is a strong and increasing interest in the study of Evolving Networks. Evolving Networks are graphs that change their topology with time. Such dynamic systems arise from several areas such as computer networks, citation networks, peer-to-peer networks, social networks, and mobile networks.
A first major issue here is that of finding abstract models that well approximate some concrete
important features of realistic scenarios. On the other hand, ''high''-realistic models are too hard to study from an analytical point of view. Finding the right trade-off between these two aspects
is a key-ingredient in this emerging research field.
A good model of Evolving Networks is then used to analyze the phenomenon of Information Spreading. This is typically performed by studying basic communication primitives (such as broadcasting and gossiping) over such dynamic structures.
In this talk, after providing the basic concepts of Evolving Networks, some recent theoretical
advances on this topic will be presented. In particular, a simple and elegant Markovian model of
Evolving Networks will be introduced and, then, some tight bounds on the Flooding Time will be
given.
Such bounds provide a strong analytical evidence of an interesting phenomenon that was previously observed from an experimental point of view only: (random) dynamicity helps Information Spreading rather than being a hurdle.
Finally, some interesting future research directions will be discussed.
=======BIBLIOGRAFIA==============
This talk mainly relies on concepts and results presented in the following works:
- Clementi A., Monti A., Pasquale F., and Silvestri R. (2007) Broadcasting in Dynamic Radio Networks. Journal of Computer and System Sciences 74(4), 2009 (Preliminary version in Proc. of Annual 26th ACM/SIGACTS Principles Of Distributed Computing 2007).
- Clementi A., Macci C., Monti A., Pasquale F., and Silvestri R. (2008) Flooding Time of Edge-Markovian Evolving Graphs. Proc. of Annual 27th ACM/SIGACTS Principles of Distributed Computing 2008.
Summary: There is a strong and increasing interest in the study of Evolving Networks. Evolving Networks are graphs that change their topology with time. Such dynamic systems arise from several areas such as computer networks, citation networks, peer-to-peer networks, social networks, and mobile networks.
A first major issue here is that of finding abstract models that well approximate some concrete
important features of realistic scenarios. On the other hand, ''high''-realistic models are too hard to study from an analytical point of view. Finding the right trade-off between these two aspects
is a key-ingredient in this emerging research field.
A good model of Evolving Networks is then used to analyze the phenomenon of Information Spreading. This is typically performed by studying basic communication primitives (such as broadcasting and gossiping) over such dynamic structures.
In this talk, after providing the basic concepts of Evolving Networks, some recent theoretical
advances on this topic will be presented. In particular, a simple and elegant Markovian model of
Evolving Networks will be introduced and, then, some tight bounds on the Flooding Time will be
given.
Such bounds provide a strong analytical evidence of an interesting phenomenon that was previously observed from an experimental point of view only: (random) dynamicity helps Information Spreading rather than being a hurdle.
Finally, some interesting future research directions will be discussed.
=======BIBLIOGRAFIA==============
This talk mainly relies on concepts and results presented in the following works:
- Clementi A., Monti A., Pasquale F., and Silvestri R. (2007) Broadcasting in Dynamic Radio Networks. Journal of Computer and System Sciences 74(4), 2009 (Preliminary version in Proc. of Annual 26th ACM/SIGACTS Principles Of Distributed Computing 2007).
- Clementi A., Macci C., Monti A., Pasquale F., and Silvestri R. (2008) Flooding Time of Edge-Markovian Evolving Graphs. Proc. of Annual 27th ACM/SIGACTS Principles of Distributed Computing 2008.
venerdì 27 marzo 2009
NUOVO SITO PER LA DIVULGAZIONE: MADDMATHS!
È finalmente attivo il nuovo sito SIMAI per la divulgazione della
http://maddmath.simai.eu/
Questa iniziativa vorrebbe essere il punto di incontro per le tante
esperienze di divulgazione già in corso e lo spunto per tante altre da
iniziare. Il sito è animato dal gruppo SIMAI-DMA creato lo scorso
anno dalla SIMAI per coordinare e promuovere le attività divulgative
nel settore della matematica applicata. A questo gruppo hanno aderito
i Politecnici di Milano e Torino, La SISSA, la Scuola Normale di Pisa,
il Centro “Anile” di Catania, l'IAC e l'IMATI del CNR e numerosi
matematici sparsi un po' per tutta la penisola.
Il nuovo sito è destinato agli studenti, i professori di scuola
superiore e ai curiosi, ma anche ai matematici che si occupano di
divulgazione, e conterrà tra l'altro:
* news sulla matematica applicata
* schede di tipo divulgativo su vari argomenti
* archivio di presentazioni multimediali (ppt, immagini, filmati)
per le scuole ed eventi vari (festival, notti bianche, settimane della
scienza...)
* commenti e articoli di carattere divulgativo e culturale.
Siete tutti invitati a collaborare, fornendo del materiale adatto allo
scopo, e anche facendoci pubblicità presso tutti i possibili
interessati. contatto Roberto Natalini roberto.natalini@cnr.it.
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