Journal & Conference Papers
M. Chroni, S.D. Nikolopoulos, and L. Palios , Encoding Watermark Numbers as Reducible Permutation Graphs using Self-inverting Permutations, Discrete Applied Mathematics (accepted)A.L. Konstantinidis, S.D. Nikolopoulos, and C. Papadopoulos , Strong Triadic Closure in Cographs and Graphs of Low Maximum Degree, Theoretical Computer Science 2018S.D. Nikolopoulos and I. Polenakis , Preventing Malware Pandemics in Mobile Devices by Establishing Response-time Bounds, Journal of Information Security and Applications, 2017S.D. Nikolopoulos and I. Polenakis , A Graph-based Model for Malware Detection and Classification using System-call Groups, Journal of Computer Virology and Hacking Techniques, 2017A. Konstantinidis, S.D. Nikolopoulos, and Ch. Papadopoulos , Strong Triadic Closure in Cographs and Graphs of Low Maximum Degree, 23rd International Computing and Combinatorics Conference (COCOON'17), LNCS Proceedings, 2017A. Mpanti, S.D. Nikolopoulos, and M. Rini , Experimental Study of the Resilience of a Graph-based Watermarking System under Edge Modifications, 21st Panhellenic Conference on Info (PCI'17), ACM ICPS Proceedings, 2017A. Mpanti, S.D. Nikolopoulos, and Iosif Polenakis , Defending Hardware-based Attacks on Trusted Computing using a Hardware-Integrity Attestation Protocol, 18th Int'l Conference on Computer Systems and Technologies (CompSysTech'17), ACM ICPS Proceedings, 2017M. Chroni, S.D. Nikolopoulos and L. Palios , Encoding Watermark Numbers as Reducible Permutation Graphs using Self-inverting Permutations, CoRR abs/1712.08482, Dec 2017.S.D. Nikolopoulos and I. Polenakis , A Model for Establishing Response-time Bounds to Prevent Malware Pandemics in Mobile Devices, 17th Int'l Conference on Computer Systems and Technologies (CompSysTech'16), ACM ICPS Proceedings, 2016A. Mpanti and S.D. Nikolopoulos , Graph-structured Watermarking using Bitonic Sequences of Self-inverting Permutations, 20th Panhellenic Conference on Info (PCI'16), ACM ICPS Proceedings, 2016S.D. Nikolopoulos and I. Polenakis , Preventing Malware Pandemics in Mobile Devices by Establishing Response-time Bounds, CoRR abs/1607.00827, July 2016.A. Mpanti and S.D. Nikolopoulos , Two RPG Flow-graphs for Software Watermarking using Bitonic Sequences of Self-inverting Permutations, CoRR abs/1607.02281, July 2016.
S.D. Nikolopoulos and I. Polenakis , A Graph-based Model for Malicious Code Detection Exploiting Dependencies of System-call Groups, 16th Int'l Conference on Computer Systems and Technologies (CompSysTech'15), ACM ICPS Proceedings, 2015S.D. Nikolopoulos and I. Polenakis , Malicious software classification based on relations of system-call groups, 19th Panhellenic Conference on Informatics (PCI'15), ACM ICPS Proceedings, 2015M. Chroni and S.D. Nikolopoulos , Encoding numbers into reducible permutation graphs using heap-ordered trees, 19th Panhellenic Conference on Informatics (PCI'15), ACM ICPS Proceedings, 2015M. Chroni and S.D. Nikolopoulos , Watermarking PDF documents using various representations of self-inverting permutations, 11th Int'l Conference on Web Information Systems and Technologies (WEBIST'15), SciTePress Digital Library, 2015M. Chroni and S.D. Nikolopoulos , Watermarking PDF Documents using Various Representations of Self-inverting Permutations, CoRR abs/1501.02686, Jan 2015.
L. Georgiadis, S.D. Nikolopoulos, and L. Palios , Join-reachability problems in directed graphs, Theory of Computing Systems, 2014S.D. Nikolopoulos, L. Palios, and C. Papadopoulos , Counting spanning trees using modular decomposition, Theoretical Computer Science, 2014M. Chroni, A. Fylakis, and S.D. Nikolopoulos , Watermarking Digital Images in the Frequency Domain: Performance and Attack Issues, Book LNBIP 189, Chapter No 5, 2014M. Chroni, A. Fylakis, and S.D. Nikolopoulos , From image to audio watermarking using self-inverting permutations, 10th Int'l Conference on Web Information Systems and Technologies (WEBIST'14), SciTePress Digital Library, 2014S.D. Nikolopoulos and Iosif Polenakis , Detecting malicious code by exploiting dependencies of system-call groups , CoRR abs/1412.8712, Dec. 2014.I. Chionis, M. Chroni, and S.D. Nikolopoulos , WaterRPG: A graph-based dynamic watermarking model for software protection, CoRR abs/1403.6658, March 2014.
M. Chroni, A. Fylakis, and S.D. Nikolopoulos, Watermarking images in the frequency domain by exploiting self-inverting permutations, Journal of Information Security, 2013
K. Ioannidou and S.D. Nikolopoulos , The longest path problem is polynomial on cocomparability graphs, Algorithmica, 2013E. Lappas, S.D. Nikolopoulos, and L. Palios , An O(n)-time algorithm for the paired-domination problem on permutation graphs, European Journal of Combinatorics, 2013I. Chionis, M. Chroni, and S.D. Nikolopoulos , A dynamic watermarking model for embedding reducible permutation graphs into software, 10th Int'l Conference on Security and Cryptography (SECRYPT'13), SciTePress Digital Library, 2013M. Chroni and S.D. Nikolopoulos , Design and evaluation of a graph codec system for software watermarking, 2nd Int'l Conference on Data Management Technologies and Applications (DATA'13), SciTePress Digital Library, 2013M. Chroni, A. Fylakis, and S.D. Nikolopoulos , Watermarking images in the frequency domain by exploiting self-inverting permutations, 9th Int'l Conference on Web Information Systems and Technologies (WEBIST'13), SciTePress Digital Library, 2013 (Best Student Paper Award)I. Chionis, M. Chroni, and S.D. Nikolopoulos , Watermarking Java application programs using the WaterRpg dynamic model, 14th Int'l Conference on Computer Systems and Technologies (CompSysTech'13), ACM ICPS Proceedings, 2013 (Best Paper Award)I. Chionis, M. Chroni, and S.D. Nikolopoulos , Evaluating the WaterRpg software watermarking model on Java application programs, 17th Panhellenic Conference on Informatics (PCI'13), ACM ICPS Proceedings, 2013
S.D. Nikolopoulos and L. Palios , An O(nm)-time certifying algorithm for recognizing HHD-free graphs, Theoretical Computer Science, 2012S.D. Nikolopoulos, L. Palios, and C. Papadopoulos , A fully dynamic algorithm for the recognition of P4-sparse graphs, Theoretical Computer Science, 2012M. Chroni and S.D. Nikolopoulos , Multiple encoding of a watermark number into reducible permutation graphs using cotrees, 13th Int'l Conference on Computer Systems and Technologies (CompSysTech'12), ACM ICPS Proceedings, 2012M. Chroni and S.D. Nikolopoulos , An efficient graph codec system for software watermarking, 36th Int'l Conference on Computers, Software, and Applications (COMPSAC'12); Workshop STPSA'12, IEEE Proceedings, 2012M. Chroni, A. Fylakis, and S.D. Nikolopoulos , A watermarking system for teaching intellectual property rights: implementation and performance, 11th Int'l Conference on Information Technology Based Higher Education and Training (ITHET'12), IEEE Proceedings, 2012M. Chroni and S.D. Nikolopoulos , An embedding graph-based model for software watermarking, 8th Int'l Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIH-MSP'12), IEEE Proceedings, 2012M. Chroni, A. Fylakis, and S.D. Nikolopoulos , Watermarking images using 2D representations of self-inverting permutations, 8th Int'l Conference on Web Information Systems and Technologies (WEBIST'12), SciTePress Digital Library, 2012M. Chroni, A. Fylakis, and S.D. Nikolopoulos , A watermarking system for teaching students to respect intellectual property rights, 4th Int'l Conference on Computer Supported Education (CSEDU'12), Poster paper, 2012
K. Ioannidou, G.B. Mertzios, and S.D. Nikolopoulos , The longest path problem has a polynomial solution on interval graphs, Algorithmica, 2011S.D. Nikolopoulos and C. Papadopoulos , A simple linear-time recognition algorithm for weakly quasi-threshold graphs, Graphs and Combinatorics, 2011L. Georgiadis, S.D. Nikolopoulos, and L. Palios , Join-reachability problems in directed graphs, 6th Int'l Computer Science Symposium in Russia (CSR'11), LNCS 6651, 2011M. Chroni and S.D. Nikolopoulos , Encoding watermark numbers as cographs using self-inverting permutations, 12th Int'l Conference on Computer Systems and Technologies (CompSysTech'11), ACM ICPS 578, 2011 (Best Paper Award)S.D. Nikolopoulos, L. Palios, and C. Papadopoulos , Counting spanning trees in graphs using modular decomposition, 5th Int'l Workshop on Algorithms and Computation (WALCOM'11), LNCS 6552, 2011
K. Asdre and S.D. Nikolopoulos , The 1-fixed-endpoint path cover problem is polynomial on interval graphs, Algorithmica, 2010K. Asdre and S.D. Nikolopoulos , A polynomial solution to the k-fixed-endpoint path cover problem on proper interval graphs, Theoretical Computer Science, 2010M. Chroni and S.D. Nikolopoulos , Encoding watermark integers as self-inverting permutations, 11th Int'l Conference on Computer Systems and Technologies (CompSysTech'10), ACM ICPS 471, 2010K. Ioannidou and S.D. Nikolopoulos , The longest path problem is polynomial on cocomparability graphs, 36th Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'10), LNCS 6410, 2010K. Ioannidou and S.D. Nikolopoulos , Harmonious coloring on subclasses of colinear graphs, 4th Int'l Workshop on Algorithms and Computation (WALCOM'10), LNCS 5942, 2010
S.D. Nikolopoulos, L. Palios, and C. Papadopoulos , Maximizing the number of spanning trees in Kn-complements of asteroidal graphs, Discrete Mathematics, 2009S.D. Nikolopoulos and C. Papadopoulos , Counting spanning trees in cographs: an algorithmic approach, Ars Combinatoria, 2009K. Ioannidou, G.B. Mertzios, and S.D. Nikolopoulos , The longest path problem is polynomial on interval graphs, 34th Int'l Symposium on Mathematical Foundations of Computer Science (MFCS'09), LNCS 5734, 2009E. Lappas, S.D. Nikolopoulos, and L. Palios , An O(n)-time algorithm for the paired-domination problem on permutation graphs, 20th Int'l Workshop on Combinatorial Algorithms (IWOCA'09), LNCS 5874, 2009K. Ioannidou and S.D. Nikolopoulos , Colinear coloring on graphs, 3rd Int'l Workshop on Algorithms and Computation (WALCOM'09), LNCS 5431, 2009
D. Koukopoulos, S.D. Nikolopoulos, L. Palios, and P.G. Spirakis , Optimal algorithms for detecting network stability, 2ed Int'l Workshop on Algorithms and Computation (WALCOM'08), LNCS 4921, 2008K. Asdre and S.D. Nikolopoulos , The 2-terminal-set path cover problem and its polynomial solution on cographs, 2nd Int'l Frontiers of Algorithmics Workshop (FAW'08), LNCS 5059, 2008
K. Asdre, K. Ioannidou, and S.D. Nikolopoulos , The Harmonious coloring problem is NP-complete for interval and permutation graphs, Discrete Applied Mathematics, 2007K. Asdre and S.D. Nikolopoulos , NP-completeness results for some problems on subclasses of bipartite and chordal graphs, Theoretical Computer Science, 2007K. Asdre and S.D. Nikolopoulos , A linear-time algorithm for the k-fixed-endpoint path cover problem on cographs, Networks, 2007S.D. Nikolopoulos and L. Palios , On the parallel computation of the biconnected and strongly connected co-components of graphs, Discrete Applied Mathematics, 2007K. Asdre, S.D. Nikolopoulos, and C. Papadopoulos , An optimal parallel solution for the path cover problem on P4-sparse graphs, J. Parallel and Distributed Computing, 2007S.D. Nikolopoulos and L. Palios , Detecting holes and antiholes in graphs, Algorithmica, 2007K. Asdre and S.D. Nikolopoulos , A polynomial solution for the k-fixed-endpoint path cover problem on proper interval graphs, 18th Int'l Workshop on Combinatorial Algorithms (IWOCA'07), College Publications, Texts in Algorithmics Vol. 10, 2007S.D. Nikolopoulos and L. Palios , An O(nm)-time certifying algorithm for recognizing HHDfree graphs, 1st Int'l Frontiers in Algorithmics Workshop (FAW'07), LNCS 4613, 2007M. Chroni, D. Koukopoulos, and S.D. Nikolopoulos , An experimental study of stability in heterogenous networks, 6th Workshop on Experimental Algorithms (WEA'07), LNCS 4525, 2007
S.D. Nikolopoulos and C. Papadopoulos , On the number of spanning trees of Kn +/- G graphs, Discrete Mathematics and Theoretical Computer Science, 2006K. Asdre and S.D. Nikolopoulos , P-tree structures and event horizon: efficient event-set implementations, J. Computer Science and Technology, 2006S.D. Nikolopoulos and L. Palios , Minimal separators in P4-sparse graphs, Discrete Mathematics, 2006S.D. Nikolopoulos and L. Palios , Recognizing HH-free, HHD-free and Welsh-Powell opposition graphs, Discrete Mathematics and Theoretical Computer Science, 2006S.D. Nikolopoulos, L. Palios, and C. Papadopoulos , A fully dynamic algorithm for the recognition of P4-sparse graphs, 32nd Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'06), LNCS 4271, 2006D. Koukopoulos and S.D. Nikolopoulos , Heterogenous networks can be unstable at arbitrarily low injection rates, 6th Conference on Algorithms and Complexity (CIAC'06), LNCS 3998, 2006
S.D. Nikolopoulos and L. Palios , Efficient parallel recognition of cographs, Discrete Applied Mathematics, 2005S.D. Nikolopoulos and L. Palios , On the recognition of bipolarizable and P4-simplicial graphs, Discrete Mathematics and Theoretical Computer Science, 2005P. Fragopoulou, S.D. Nikolopoulos, and L. Palios , Multi-source trees: algorithms for minimizing eccentricity metrics, 16th Int'l Symposium on Algorithms and Computation (ISAAC'05), LNCS 3827, 2005S.D. Nikolopoulos and L. Palios , Maximum-size subgraphs of P4-sparse graphs admitting a perfect matching, 10th Panhellenic Conference on Informatics (PCI'05), LNCS 3746, 2005S.D. Nikolopoulos and L. Palios , Recognizing HHDS-free graphs, 31st Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'05), LNCS 3787, 2005S.D. Nikolopoulos and L. Palios , Adding an edge in a cograph, 31st Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'05), LNCS 3787, 2005
S.D. Nikolopoulos, C. Nomikos, and P. Rondogiannis , A limit characterization for the number of spanning trees of graphs, Information Processing Letters, 2004S.D. Nikolopoulos and L. Palios , Parallel algorithms for P4-comparability graphs, J. Algorithms, 2004S.D. Nikolopoulos and L. Palios , Parallel algorithms for recognizing P5-free and coP5-free weakly chordal graphs, Parallel Processing Letters, 2004S.D. Nikolopoulos and L. Palios , Algorithms for P4-comparability graph recognition and acyclic P4-transitive orientation, Algorithmica, 2004S.D. Nikolopoulos and C. Papadopoulos , The number of spanning trees in Kn-complements of quasi-threshold graphs, Graphs and Combinatorics, 2004S.D. Nikolopoulos , Parallel algorithms for Hamiltonian problems on quasi-threshold graphs, J. Parallel and Distributed Computing, 2004K.W. Chong, S.D. Nikolopoulos, and L. Palios , An optimal parallel co-connectivity algorithm, Theory of Computing Systems, 2004S.D. Nikolopoulos and L. Palios , Recognizing HHD-free and Welsh-Powell opposition graphs, 30th Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'04), LNCS 3353, 2004S.D. Nikolopoulos and L. Palios , Hole and antihole detection in graphs, 15th ACM-SIAM Symposium on Discrete Algorithms (SODA'04), Vol. 1, 2004
S.D. Nikolopoulos and L. Palios , Recognizing bipolarizable and P4-simplicial graphs, 29th Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'03), LNCS 2880, 2003
S.D. Nikolopoulos , Coloring permutation graphs in parallel, Discrete Applied Mathematics, 2002S.D. Nikolopoulos and L. Palios , On the recognition of P4-comparability graphs, 28th Int'l Workshop on Graph-Theoretic Concepts in Computer Science (WG'02), LNCS 2573, 2002
S.D. Nikolopoulos , Optimal Gray-code labeling and recognition algorithms for hypercubes, Information Sciences, 2001S.D. Nikolopoulos and L. Palios , Recognition and orientation algorithms for P4-comparability graphs, 12th Int'l Symposium on Algorithms and Computation (ISAAC'01), LNCS 2223, 2001
S.D. Nikolopoulos and C. Papadopoulos , On the performance of the First-Fit coloring algorithm on permutation graphs, Information Processing Letters, 2000S.D. Nikolopoulos , Recognizing cographs and threshold graphs through a classification of their edges, Information Processing Letters, 2000
M. Andreou and S.D. Nikolopoulos , NC coloring algorithms for permutation graphs, Nordic J. Computing, 1999S.D. Nikolopoulos and P. Rondogiannis , On the number of spanning trees of multi-star related graphs, Information Processing Letters, 1998F. Harary and S.D. Nikolopoulos , On complete systems of invariants for small graphs, Intern. J. Computer Mathematics, 1997S.D. Nikolopoulos and G. Samaras , Sub-optimal solutions to track detection problem using graph theoretic concepts, J. Systems Architecture, 1997S.D. Nikolopoulos , Parallel block-finding using distance matrices, J. Parallel Algorithms and Applications, 1996S.D. Nikolopoulos , Constant-time parallel recognition of split graphs, Information Processing Letters, 1995S.D. Nikolopoulos and S.D. Danielopoulos , Parallel computation of perfect elimination schemes using partition techniques on triangulated graphs, Computers and Mathematics with Applications, 1995S.D. Nikolopoulos and S.D. Danielopoulos , On the parallel evaluation of DWBA integrals, Intern. J. Computer Mathematics, 1994S.D. Nikolopoulos and S.D. Danielopoulos , Odd-even, compare-exchange parallel sorting, Microprocessing and Microprogramming, 1994S.D. Nikolopoulos and S.D. Danielopoulos , Fast parallel algorithms for finding cutpoints and bridges of undirected graphs, J. Parallel Algorithms and Applications, 1994S.D. Nikolopoulos and R. MacLeod , An experimental analysis of event set algorithms for discrete event simulation, Microprocessing and Microprogramming, 1993
S.D. Nikolopoulos, A. Pitsillides, and D. Tipper , Addressing network survivability issues by finding the K-best paths through a trellis graph, 16th IEEE Conference on Computer Communications (INFOCOM'97), IEEE Proceedings, 1997G. Samaras, S.D. Nikolopoulos, K. Britton, and A. Cirton , Managing transaction identifiers in the Peer-to-Peer distributed transactional environment, 9th Int'l Conference on Parallel and Distributed Computing Systems (PDCS'96), Vol. 2, 1996S.D. Nikolopoulos and G. Samaras , Sub-optimal approach to track detection for real-time systems, 21st Euromicro Conference on Design of Hardware and Software Systems (EUROMICRO'95), Vol. 1, 1995F. Harary and S.D. Nikolopoulos , Graph isomorphism problem for small graphs, 2nd Int'l Conference on Digital Signal Processing (DSP'95), Vol. 1, 1995S.D. Nikolopoulos , Parallel recognition and location algorithms for chordal graphs using distance matrices, 3rd Int'l Conference on Parallel and Vector Processing (CONPAR'94), LNCS 854, 1994
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Reports
