National Technical Universtity of Athens
Foto Afrati
Foto Afrati

Professor, Fellow of ACM
National Technical Universtity of Athens
School of Electrical and Computing Engineering
Division of Communication, Electronic and Information Engineering
Zographou Campus
Iroon Polytechniou 9
15780 Athens, Greece
E-mail: afrati AT softlab. ece. ntua. gr
Phone: +30-210-7722498 (Office), Fax: +30-210-7722499




New


Alumni


Publications

My DBLP entry.

Conference and Journal Papers

  • By year:

       2010 | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |

        1999 |
1998 | 1997 | 1996 | 1995 | 1994 | 1993 | 1992 | 1991 | 1990 |

        1989 | 1988 | 1987 | 1986 | 1985 | 1984 | 1983 | 1982 | 1981 | 1978 

          Telecommunications

    Books
 
  • Foto N. Afrati, Papageorgiou, G.: Algorithms: Design and Analysis of Algorithms (in greek),  Symmetria,  Athens, 1993, second edition with 25% new material, 2005.
  • Database Theory - ICDT '97 6th International Conference, Edited by Foto N. Afrati and Ph.G. Kolaitis, Lecture Notes in Computer Science, Volume 1186 , Springer, 1997.
  • Foto N. Afrati: Introduction to Information Theory (in greek), Symmetria,  Athens, 1985.

 Chapters in books





    2010

2009

   2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

1996

1995

1994

1993

1992

1991

1990

1989

1988

1987

1986

1985

  • Foto N. Afrati, Christos H. Papadimitriou, George Papageorgiou: The Complexity of Cubical Graphs. Information and Control 66(1/2): 53-60, 1985.
  • Foto N. Afrati, M. Anagnostou, E.N. Protonotarios: Performance Evaluation of Hybrid ARQ Protocols. Proceedings of IEEE Symposium on Information Theory, June 1985.
  • Foto N. Afrati, M. Dendrinos: Symmetry and Cyclicity Properties of some Low Complexity Codes. Proceedings of IEEE Symposium on Information Theory, June 1985.
  • Foto N. Afrati, M. Anagnostou: On the Complexity and Accuracy of Algorithms used for the Performance Evaluation of ARQ Protocols. Proceedings of the IEEE International Conference MELECON, 1985.
  • Foto N. Afrati, V. Papaspirou : Optimal Extension of a Linear Code. Proceedings of the IEEE International Conference MELECON, 1985.

1984

1983

  • Foto N. Afrati, D. Ballas: Analysis of Error Correcting Codes for the Binary Symmetric Channel. Proceedings MECO 1983.
  • Foto N. Afrati, M. Anagnostou, N. Mikroudis: A Hybrid ARQ Scheme using Convolutional Codes. Proceedings MECO 1983.
  • Foto N. Afrati, M. Anagnostou, N. Mikroudis: A Hybrid Scheme for the Improvement of the ARQ Protocols.  Proceedings of the IEEE International Conference MELECON, 1983.
  • Foto N. Afrati: A Random Search Algorithm for the Construction of Ternary Linear Block Codes. Proceedings of the IEEE International Conference MELECON, 1983.

1982

  • Foto N. Afrati: A Graph-Theoretic Approach to the Binary Linear Block Code Construction. Proceedings of the IEEE International Symposium on Information Theory, 1982.

1981

  • Foto N. Afrati: A Branch-and-Bound Method for the Construction of Binary Linear Block Codes. Proceedings of the IEEE International Conference MELECON, 1981.

1978

  • Foto N. Afrati, A.G. Constantinides: The Use of Graph Theory in Binary Block Code Construction. Proceedings of the IEEE International Conference on Digital Signal Processing, 1978.



   Optimization techniques for database queries



  
Algorithms and Complexity

    
   Parallel and Distributed Computation





  
Logic in Databases -  Expressivenes of query languages


  
Heterogeneous Databases (Information Integration and Data Exchange)


  
Processing of large data - Data Mining


   Telecommunications


  • Foto N. Afrati,P. Paschos, M. Anagnostou: Deterministic Access Protocols for Packet radio Networks. International Journal of Digital and Analog Communication Systems, Vol. 6 1993, pp. 151-160.
  • Foto N. Afrati, M. Anagnostou, E.N. Protonotarios: Performance Evaluation of Hybrid ARQ Protocols. Proceedings of IEEE Symposium on Information Theory, June 1985.
  • Foto N. Afrati, M. Dendrinos: Symmetry and Cyclicity Properties of some Low Complexity Codes. Proceedings of IEEE Symposium on Information Theory, June 1985.
  • Foto N. Afrati, M. Anagnostou: On the Complexity and Accuracy of Algorithms used for the Performance Evaluation of ARQ Protocols. Proceedings of the IEEE International Conference MELECON, 1985.
  • Foto N. Afrati, V. Papaspirou : Optimal Extension of a Linear Code. Proceedings of the IEEE International Conference MELECON, 1985.
  • Foto N. Afrati, M. Dendrinos: Considerations on Low Complexity Codes Concerning Symmetry and Cyclicity . Proceedings DIGITECH, 1984.
  • Foto N. Afrati, D. Ballas: Analysis of Error Correcting Codes for the Binary Symmetric Channel. Proceedings MECO 1983.
  • Foto N. Afrati, M. Anagnostou, N. Mikroudis: A Hybrid ARQ Scheme using Convolutional Codes. Proceedings MECO 1983.
  • Foto N. Afrati, M. Anagnostou, N. Mikroudis: A Hybrid Scheme for the Improvement of the ARQ Protocols.  Proceedings of the IEEE International Conference MELECON, 1983.
  • Foto N. Afrati: A Random Search Algorithm for the Construction of Ternary Linear Block Codes. Proceedings of the IEEE International Conference MELECON, 1983.
  • Foto N. Afrati: A Graph-Theoretic Approach to the Binary Linear Block Code Construction. Proceedings of the IEEE International Symposium on Information Theory, 1982.
  • Foto N. Afrati: A Branch-and-Bound Method for the Construction of Binary Linear Block Codes. Proceedings of the IEEE International Conference MELECON, 1981.
  • Foto N. Afrati, A.G. Constantinides: The Use of Graph Theory in Binary Block Code Construction. Proceedings of the IEEE International Conference on Digital Signal Processing, 1978.


Teaching


   Undergraduate Cources

  • Discrete Mathematics in Computer Science
    We use the Gradiance Online Accelerated Learning

    Sets. Finite and infinite sets. Countable sets. The diagonalizatiom method. The inclusion-exclusion principle. Mathematical induction. Combinations and permutations. Introduction to format languages and finite automata. Grammars. Groups, rings and fields. Isomorphisms, automorphisms and homeomorphisms. Permutation groups. Relations. The job scheduling problem. Binary relations, lattices, partially ordered sets. Equivalence relations and partitions. Introduction to Boolean algebra.

  • Theory of Computation

    Computational models for sequential algorithms. Turing machine. Random access machine (RAM). The class of polynomial problems. Algorithms on graphs. Shortest path. Minimum spanning tree. Biconnectivity-Strongly connected components. Maximum flow. The class of non-deterministically polynomial (NP) problems. Polynomial reductions. NP-complete problems. Parallel algorithms. Computational models for parallel algorithms. Interconnection networks. The parallel random access machine (PRAM). The class NC. log-space reductions. P-compete problems. Efficient and optimal parallel algorithms.

  • Information Theory

    The uncertainly function as a measure of information. Properties of the uncertainty function. Source coding-Huffman codes. Optimum codes. Shannon's first theorem. Channel capacity. Shannon,s second theorem. Error correcting codes. Lower and upper bounds. The sphere-packing bound. Hamming codes. Linear codes. Cyclic codes, BCH codes. Error correcting capability of BCH codes. Shift registers for encoding and decoding cyclic codes. Continous channel with Gaussian noise. Average error probability.


  Graduate Cources

What is Data Mining, Applications, The Data-Mining Communities, Association-Rule Mining: Association Rules and Frequent Itemsets, Market­Basket Mining, The A­Priori Algorithm, PCY Algorithm, Low-Support/High Correlation: Min Hashing Algorithm, LSH Algorithm, k­Min Hashing Algorithm, Hamming LSH Algorithm, Query Flocks: Query Flock Notation, Execution Strategies, Optimal Query Flock, Searching the Web: Page Rank, Problems With Real Web Graphs, Hubs and Authorities, Google Solution to Dead Ends and Spider Traps, Google Anti­Spam Devices, Web Mining, The DICE Engine, Books and Authors, What is Pattern, Finding Data Occurrences Given Data,, Finding Data Occurrences Given Patterns, Clustering: Distance Measure, The Curse of Dimensionality, Approaches to Clustering, The k-Means Algorithm, The BFR Algorithm Fastmap in Clustering Algorithms, Hierarchical Clustering, The GRGPF Algorithm, CURE Algorithm, Matching Sequences: Fourier Transforms as Indexes for Sequences, Matching Queries to Sequences of the Same Length, Queries That are Shorter than the Sequences, Trails, Matching Queries of Arbitrary Length, Mining Event Sequences: Episode Mining, Monotonicity of Episodes and the A­Priori Algorithm, Checking Parallel Episodes, Checking Serial Episodes, Counting Composite Events.

Introduction to SQL. Relational Algebra. Introduction to Datalog, Stratified Negation, Stable and Well-Founded Models. Conjunctive queries with Negation and Arithmetic. Query Containment. Answering Queries using Views, the Bucket algorithm, the inverse rule algorithm. Data Dependencies, Normalization. Acyclic Hypergraphs, Computing Acyclic Joins. The Universal Relation. Introduction to Magic sets, Rule-goal trees, the magic-sets algorithm.

Online Homeworks: Gradiance