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Stavros D. Nikolopoulos

Researcher at University of Ioannina

Publications -  159
Citations -  1512

Stavros D. Nikolopoulos is an academic researcher from University of Ioannina. The author has contributed to research in topics: Chordal graph & Indifference graph. The author has an hindex of 20, co-authored 148 publications receiving 1377 citations. Previous affiliations of Stavros D. Nikolopoulos include Pierre-and-Marie-Curie University & National and Kapodistrian University of Athens.

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Characterizing Watermark Numbers encoded as Reducible Permutation Graphs against Malicious Attacks.

TL;DR: This work theoretically study the oldest watermarking codec system, called W-RPG, in order to investigate and prove its resilience to edge-modification attacks on the flow-graphs of F[\pi^*] through the use of self-inverting permutations.
Book ChapterDOI

Maximum-Size subgraphs of p4-sparse graphs admitting a perfect matching

TL;DR: This paper addresses the problem of computing a maximum-size subgraph of a P4-sparse graph which admits a perfect matching, and establishes a characterization of such subgraphs, and describes an algorithm which runs in O(n+m) time and space.
Book ChapterDOI

Parallel Recognition and Location Algorithms for Chordal Graphs Using Distance Matrices

TL;DR: The overall time and processor complexity of both algorithms are O(logn) and O(max{δ2·n2/logn, nβ+DG}), respectively, imply that the proposed algorithms improve in performance upon the best-known algorithms for these problems.
Journal ArticleDOI

Sub-optimal solutions to track detection problem using graph theoretic concepts

TL;DR: This paper demonstrates how the problem of tracking targets, which appear as either straight or curved lines in two-dimensional display images (or data images) can be formulated in terms of a directed weighted graph model and how dynamic programming techniques can be efficiently applied to reach an optimal or sub-optimal solution.
Journal ArticleDOI

Parallel block-finding using distance matrices

TL;DR: It is shown that the location of all cut vertices and bridges of a graph can be done in time O(logδ + t D) by using O(n m/t d) processors, where δ is the maximum degree of a vertex in G.