Για όσους ενδιαφέρονται για Θεωρητική Πληροφορική

[AnINffected]

Ναι, το φαντάστηκα.Ας είναι καλά ο άνθρωπος.

[enum21]

geia sas,
authn thn Paraskeuh tha mas parousiasei th diplwmatikh ths h Aggelikh,
Akolouthei titlos kai abstract.
Opws panta sthn A36,
Meta apo diafores eishghseis, proteinw na to ksekinhsoume stis 4 anti
gia 4:15, etsi wste na pame meta kapou oloi mazi na doume to prwto
mats tou Mundial pou ksekinaei stis 5:)

H Aggeliki Charakida tha paroysiasei ti diplwmatiki tis
tin Paraskeyi 11/6, wra 16:00, stin aithousa A36.
Akolouthoyn titlos kai perilipsi.

Τίτλος : ¶μεσος Χρωματισμός Γράφων (On-line Graph Coloring)
Περίληψη :
Ο άμεσος χρωματισμός γράφων αφορά την απόδοση χρωμάτων στις κορυφές
τους, καθώς αυτές εμφανίζονται ο μία μετά την άλλη, έτσι ώστε
γειτονικοί κόμβοι να μην αποκτήσουν το ίδιο χρώμα.
Το πρόβλημα του άμεσου χρωματισμού γράφων αποτελεί δημοφιλές
ερευνητικό πεδίο, αφού μοντελοποιεί πολλά προβλήματα ιδιαίτερου
πρακτικού ενδιαφέροντος, όπως προβλήματα χρονοπρογραμματισμού
εργασιών και δέσμευσης πόρων στον τομέα των συστημάτων και των δικτύων
υπολογιστών.
Σκοπός της διπλωματικής είναι η παρουσίαση των μέχρι σήμερα γνωστών
αποτελεσμάτων σχετικά με την απόδοση (λόγο ανταγωνισμού) αλγορίθμων
άμεσου χρωματισμού γράφων. Παρουσιάζονται άνω ή/και κάτω φράγματα για
το λόγο ανταγωνισμού οποιουδήποτε άμεσου αλγορίθμου, καθώς και του
πιο κλασσικού από αυτούς, του First Fit αλγόριθμου, για διάφορες
κατηγορίες γράφων (γενικοί και διμερείς γράφοι, γράφοι διαστημάτων και
κυκλικών τόξων, χορδικοί γράφοι, δένδρα) .

[darkness]

enum21, ξεχάστηκες!

Authn thn ebdomada tha exoume to teleutaio theory tea ths xronias me 2
parousiaseis diplwmatikwn.
Epeidh thn Paraskeuh yparxei seminario tou tmhmatos mas, tha exoume to
tea thn Pempth 11-1, sthn aithousa A41.

Akolouthei titlos kai abstract gia tis parousiaseis

11-12: Iwanna Anastasopoulou
Title: Analysis of Path Coloring Games

Abstract:
We study a class of routing and path coloring games in all-optical networks.
We consider a non-cooperative model, where each player corresponds to
a request for communication between 2 nodes of the network. Each
player is interested in minimizing his own cost by selecting the most
appropriate wavelength. This model is mainly motivated by the fact
that centralized control in large scale networks may be either
infeasible or impractical. We assume that each user is charged
according to a given payment function.
We study several different payment functions for the players and we
examine for each one of them and for specific topologies, the
following questions:
Do any pure Nash Equilibria exist?
If pure Nash Equilibria exist, what is the Price of Anarchy?
Can we decide in polynomial time if a strategy profile is an equilibrium?
Can we compute an equilibrium in polynomial time?

12-1: Dhmhtrhs Diamanths
Title: Power Management Algorithms in Multiprocessor Systems

Abstract:
Power Management Algorithms seek to minimize the energy consumption
and temperature of the processor while meeting the deadlines of the
jobs that are being processed.
Power management algorithms is a relatively new research field and its
popularity is on the rise due to the ever-growing need for energy and
the difficulty in cooling modern day computing systems.
The purpose of this thesis is to present power management algorithms
for energy minimization in multiprocessor environments such as
computer clusters, multicore systems etc.
The presentation includes some fundamental single processor power
management algorithms, algorithms for a 2 processor system as well as
algorithms for a purely multiprocessor setting.
Furthermore, it deals with scenarios where besides the minimization of
the energy consumption, we seek to optimize other criteria as well
(such as makespan, throuphput and total flow).

[enum21]

@darkness

πάλι καλά που το πόσταρες εσύ γιατί είναι για σήμερα!

[elsupreme]

Έγινε κανονικά σήμερα ? (Απεργία κλπ.)

[darkness]

Πρέπει να έγινε. Εκεί ήμουν αλλά για άλλο σκοπό και δυστυχώς δεν πρόλαβα να πάω.

Και μην ξεχνάμε, για αύριο:

Στα πλαίσια της Σειράς Σεμιναρίων του τμήματός μας, θα διεξαχθεί
εκτάκτως την Παρασκευή 18 Ιουνίου στις 4μμ ομιλία του Δρ. Βαγγέλη
Πάσχου, καθηγητή του πανεπιστήμιου Paris-Dauphine και διευθυντή του
εργαστηρίου LAMSADE. Η ομιλία θα διεξαχθεί στην αίθουσα Α41 (Πατησίων
76, Πτέρυγα Αντωνιάδου, 4ος όροφος).

ιστότοπος: http://seminar.cs.aueb.gr/

τίτλος: Moderately exponential approximation of intractable problems

περίληψη:
This talk presents a possible trade-off between polynomial
approximation and exact computation. We show how using ideas from both
fields one can design approximation algorithms for several
combinatorial problems achieving ratios that cannot be achieved in
polynomial time (unless some very unlikely complexity conjecture is
confirmed) with worst-case complexity much lower (though
super-polynomial) than that of an exact computation.

[darkness]

Υπενθύμιση: από αύριο το theory tea ξεκινά και πάλι.

Geia se olous,

opws eixa pei,
ksekiname authn thn Paraskeuh.

Tha dwsw mia omilia gia cooperative games.
Stis prohgoumenes parousiaseis eidame arketa themata panw se non-cooperative
games,
paixnidia dhladh opou kathe paikths einai on his own kai krinei panta me
bash to diko tou utility.

Thn Paraskeuh tha doume ena diaforetiko montelo paigniwn opou epitrepetai h
sunergasia metaksu paiktwn.
Tha kanoume prwta mia mikrh eisagwgh gia cooperative games kai meta tha
parousiasw kapoia themata apo mia prosfath ergasia mas (akolouthei titlos
kai abstract).
Opws panta sthn A36 stis 4.

[L30N]

Υπενθύμιση: από αύριο το theory tea ξεκινά και πάλι.

Geia se olous,

opws eixa pei,
ksekiname authn thn Paraskeuh.

Tha dwsw mia omilia gia cooperative games.
Stis prohgoumenes parousiaseis eidame arketa themata panw se non-cooperative
games,
paixnidia dhladh opou kathe paikths einai on his own kai krinei panta me
bash to diko tou utility.

Thn Paraskeuh tha doume ena diaforetiko montelo paigniwn opou epitrepetai h
sunergasia metaksu paiktwn.
Tha kanoume prwta mia mikrh eisagwgh gia cooperative games kai meta tha
parousiasw kapoia themata apo mia prosfath ergasia mas (akolouthei titlos
kai abstract).
Opws panta sthn A36 stis 4.

Ξέρει κανείς τι ισχύει τώρα για τα theory tea ?

[enum21]

Ξέρει κανείς τι ισχύει τώρα για τα theory tea ?

Geia se olous,

Logw ths eksetastikhs den tha exoume theory tea tis epomenes ebdomades.
H epomenh omilia tha ginei stis 11 Febrouariou apo thn Maria Polukarov pou
tha mas episkeftei apo to University of Southampton. Titlos kai abstract tha
anakoinwthoun se liges meres.

από την επόμενη Παρασκευή.

[enum21]

από ανακοίνωση

Tha exoume thn ekshs omilia thn Paraskeuh sto theory tea.
A36 stis 4.

Speaker: Maria Polukarov, University of Southampton
Title: Congestion-Averse Games

Abstract:


Congestion games---in which players strategically choose from a set of
``resources'' and derive utilities that depend on the congestion on each
resource---are important in a wide range of applications. However, to
date, such games have been constrained to use utility functions that are
linear sums with respect to resources. To remove this restriction, we consider
a generalisation to the case where a player's payoff can be given by any
real-valued function over the set of possible congestion vectors. Under weak
assumptions on the structure of player strategy spaces, we constructively prove
the existence of a pure strategy equilibrium for the very wide class of these
generalised games in which player utility functions are
congestion-averse---i.e.,
monotonic, submodular and independent of irrelevant alternatives.
Although, as we
show, these games do not admit a generalised ordinal potential function
(and hence---the finite improvement property), any such game does possess
a Nash equilibrium in pure strategies. A polynomial time algorithm for computing
such an equilibrium is presented. Moreover, we show that if a player
utility function does not satisfy any one of the congestion-averse
conditions, then a pure strategy equilibrium need not to exist, and in fact
the determination of whether or not a game has a pure strategy Nash
equilibrium is NP-complete. We further prove analogous results for our
assumed properties of player strategy spaces, thus showing that current
assumptions on strategy and utility structures in this model cannot be
relaxed anymore.