division of theoretical computer science
TRANSCRIPT
Outline
• People• Teaching• Mobility/Collaborations• Research
People 10 faculty: 6 full, 2 associate, 2 assistant
(became 8 in 2004), average age=47,+1 emeritus
• Non-faculty: 21 MSc student theses,13 PhD students (funded), 17 completed since 2007,11 Postdocs / Collaborators (most unfunded),1 secretary
• Our graduates:* PhD students (UC Berkeley, Columbia, Cornell, Stony Brook, UIChicago, CWI, TUEindhoven, RISC-Linz)* Postdocs (MPI, CNRS, INRIA, U.Aarhus, U.Vienna),* Faculty (U.Liverpool, AUEB, U.Piraeus, U.Crete, U.Aegean, U.Peloponnisos, ATEI)
Teaching• 6 core undergrad courses,
Service outside the Dept,Most popular non-core course: Graphics
• Participate in 4 graduate programs:* own (new for modernity/strengths),* Μεταπτυχιακό Πρόγραμμα Λογικής και Αλγορίθμων (joint w/Math, NTUA),* Econ. & Admin. of Telecom Networks,* Info Tech. in Medicine & Biology.
New Theoretical CS direction Algorithms Computational Complexity
Randomized Algorithms Algorithmic Game theory Approximate Algorithms Combinatorial Optimization Theory of Programming Languages Cryptography Computational Geometry Graphics and Visualization Parallel Algorithms Scientific Computing
Online Algorithms Algorithmic Graph theory Computational Algebra Algorithms in Structural bioinformatics Linear and Nonlinear programming
Mobility/CollaborationsErasmus for under/grad students, faculty:* outgoing (U.Paris 6, U.Nice, U.Lugano),* incoming (U.Evry).* Internships at INRIA.
Collaborations:* UC Berkeley, Microsoft, McMaster* INRIA, Paris 6* U.Crete, U.Patras, NTUA (CS, Naval), Math dept
Sabbaticals:* Columbia, Houston, Tel Aviv U.* CNRS, ECP, ENS Paris, U.Cyprus
Visitors/sabbaticals from:* Stanford, U.Paris-Dauphine, W.Laurier U.
ResearchPublications:* Nature, Science, J. ACM, SIAM J. Computing, SIAM J. Numerical Analysis, Numerische Mathematik, Linear Algebra & Applications,IEEE Trans. Parallel Distr. Systems, IEEE TPAMI, IJCV.* FOCS, STOC, SODA, Crypto, Eurocrypt.* US Patents
•EU funding:2 ERC Startup Grants, IST, FET, Marie Curie Net+ Greek projects (ΠΕΝΕΔ, Πυθαγόρας, Ηράκλειτος)+ NSF, NSERC
•Visibility/service:* PCs, e.g. chair ACM ISSAC'11,co-chair IEEE Soft. Engin. Context Aware Syst. & Appl. '08,'09.* Journal editors, e.g. J.Computer & System Sciences.
Research areas
1) Algorithms and Complexity2) Theory and Applications3) Scientific Computing
Covers almost all areas of CS Theory
Research area 1
1. Algorithms and Complexity2. Theory and Applications3. Scientific Computing
• Dimitris Achlioptas• Elias Koutsoupias• Stavros Kolliopoulos• Vassilis Zissimopoulos
From Graphs to the Internet
Dimitris Achlioptas
Specializes in: Dimension reduction
Recent Work: Algorithmic Phase Transitions in Constraint Satisfaction Problems
Publishes in: Science, Nature,J.ACM, SIAM J.Computing, FOCS, STOC
Random structures and Stochastic Algorithms
Solution-Space Geometry
No SolutionsAlgorithmic ThresholdNP-hardness
Density
Elias Koutsoupias
Algorithmic Decision Making
Price of Anarchy & Mechanism Design
STOC, FOCS, Algorithmica
- Online algorithms -Algorithmic game theory
• Specializes in:
• Recent Work:
• Publishes in:
Price of anarchy
Price of anarchy = Selfish solution / Optimal solutionQuantifies loss due to selfishness. Selfish behavior can lead to suboptimal traffic.
Applications: game theory, networks, Internet[K-Papadimitirou'99] (>1000 citations)
Vassilis Zissimopoulos
Design and Analysis of Algorithms
Approximation algorithms for graph problems
IEEE Trans. Parallel Distributed Systems, Computer Networks, Discrete Applied Math, Theoretical Comp. Science
Graph Algorithms• Specializes in:
• Recent Work:
• Publishes in:
clustering data represented by big graphs: genetic/social nets
Constrained-cardinality optimization : Densest k-subgraph
Stavros Kolliopoulos
Approximation Algorithms for Combinatorial Optimization
Algorithmic graph theory from the viewpoint of parameterized complexity
FOCS, SODA; ACM Trans. Algorithms,SIAM J.Computing
- Scheduling, Packing and Covering- Algorithmic game theory• Specializes in:
• Recent Work:
• Publishes in:
Approximate optimization
• Given machine, N weighted tasks,fixed number of disinct due dates:
• Settle approximability, design FPTAS(Fully Polynomial-Time Approximation Scheme).
• k disjoint paths in f(k)n3, huge f(k):
• Algorithm for planar graphs, tight bound on f(k); improving f(k) requires new approach.
• [Kolliopoulos et al, ACM Transact. on Algorithms'11, Proc. ICALP'11]
Research area 2
1. Algorithms and Complexity2. Theory and Applications3. Scientific Computing
• Panagiotis Rondogiannis• Aggelos Kiayias• Ioannis Emiris• Theoharis Theoharis
Panagiotis Rontogiannis
- Math semantics for Boolean grammars- First purely logical semantics of negation
ACM Trans. Computational Logic, Information & Computation, Intern. Conf. Logic Programming, Developments in Language Theory
- Logic and Functional Programming- Non-monotonic Reasoning
• Specializes in:
• Recent Work:
• Publishes in:
Theory of Programming Languages
Aggelos Kiayias
Cryptography, Computer Security
Applications of coding theory to cryptography
Book: Encryption for Digital ContentCrypto, Eurocrypt
• Specializes in:
• Recent Work:
• Publishes in:
Public-key cryptography
Discrete math in broadcast encryption
Key-poset representation of 8-user broadcast encryption[Encryption for Digital Content, Springer]
Kiayias' talk follows
Ioannis Emiris
Computational Algebra and Geometry
- Real root isolation- Structural bioinformatics
ACM Int. Symp. Symbolic & Algebraic ComputationIEEE FOCS, SIAM/ACM SPModeling, IEEE ICRA, J.ACM, J.Symbolic Computation
- Sparse resultants for system solving- Nonlinear computational geometry• Specializes in:
Recent Work:
• Publishes in:
Lab of Geometricand Algebraic Algorithms
erga.di.uoa.gr
• People: 1 faculty,2 collaborators (in other dept's),3 funded Postdocs / another 3 since 2002,2 PhD students / 4 completed,3 Msc students / 9 graduated+ collaboration with INRIA Sophia-Antipolis
• Current projects: FET-Open, M. Curie NetworkSince 2002: FET, ΠΕΝΕΔ, Πυθαγόρας, ΕΝΤΕR
PhD theses
Completed:- Fastest equation solver over the reals (C++)- Real-time complex Voronoi diagrams (1s/ellipse)- Matrix formula for sparse resultant- Robotics platform for ankle physiotherapy
Current:- Change of representation in CAD- High-dim data-structures: polytopes and searching
From geometric to molecular modeling
Theoharis Theoharis
Top results in NIST's Face Recognition Challenge
International textbook “Graphics & Visualization”IJCV, IEEE Trans. PAMI, IEEE CG&A
- 3D object retrieval- Face recognition
• Specializes in:
• Recent Work:
• Publishes in:
Graphics and Biometrics
Shape descriptors for 3D Object Retrieval
InterClass IntraClass
Research area 3
1. Algorithms and Complexity2. Theory and Applications3. Scientific Computing
• Nikolaos Misirlis• Filippos Tzaferis• Nikolaos Apostolatos (emeritus)
Nikolaos Missirlis
Numerical Solution of PDEs
Iterative methods for Load Balancing
Numerische Mathematik, SIAM J.Numerical Analysis, Linear Algebra & Applications, Theoretical Computer Science, EuroPar, PARA, ENUMATH
Parallel Iterative Methods• Specializes in:
• Recent Work:
• Publishes in:
Philippos Tzaferis
Parallel Numerical Methods
Iterative methods for 2-cyclic matrices
Linear Algebra & Applications, Parallel Algorithms & Appli., EUROPAR, PARA, ENUMATH, ParCo
Parallel solution of linear systems• Specializes in:
• Recent Work:
• Publishes in:
Α Β
Δ Γ
Α Β
Δ Γ
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Δ Γ
Load Balancing for Numerical Weather Prediction
SKIRON was a featured EPET-II project.Now in operation at the Hellenic Meteorological Office (EMY).
Future work
• Collaboration within division / dept• Recruit the best• Strong(est) theory group in Greece• Strong at the European level
Thank you