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    Chapter and Conference Paper

    Two Broadcasting Problems in FaultyHypercubes

    We consider two broadcasting problems in the n-dimensional hypercube under the shouting communication mode, i.e. any node of a network can inform all its neighbours in one time step. In addition, during any ti...

    Stefan Dobrev, Imrich Vrťo in Graph-Theoretic Concepts in Computer Science (1999)

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    Chapter and Conference Paper

    Computing Input Multiplicity in Anonymous Synchronous Networks with Dynamic Faults

    We consider the following problem: Each processor of the network has assigned a (not necessarily unique) input value. Determine multiplicity of each input value. Solving this problem means any input-symmetric ...

    Stefan Dobrev in Graph-Theoretic Concepts in Computer Science (2000)

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    Chapter and Conference Paper

    Improved Bounds for Optimal Black Hole Search with a Network Map

    A black hole is a harmful host that destroys incoming agents without leaving any observable trace of such a destruction. The black hole search problem is to unambiguously determine the location of the black hole....

    Stefan Dobrev, Paola Flocchini in Structural Information and Communication C… (2004)

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    Chapter and Conference Paper

    Finding Short Right-Hand-on-the-Wall Walks in Graphs

    We consider the problem of perpetual traversal by a single agent in an anonymous undirected graph G. Our requirements are: (1) deterministic algorithm, (2) each node is visited within O(n) moves, (3) the agent us...

    Stefan Dobrev, Jesper Jansson in Structural Information and Communication C… (2005)

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    Chapter and Conference Paper

    Local Construction of Planar Spanners in Unit Disk Graphs with Irregular Transmission Ranges

    We give an algorithm for constructing a connected spanning subgraphs(panner) of a wireless network modelled as a unit disk graph with nodes of irregular transmission ranges, whereby for some parameter 0 < r ≤ 1 t...

    Edgar Chávez, Stefan Dobrev, Evangelos Kranakis in LATIN 2006: Theoretical Informatics (2006)

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    Chapter and Conference Paper

    On Fractional Dynamic Faults with Threshold

    Unlike localized communication failures that occur on a fixed (although a priori unknown) set of links, dynamic faults can occur on any link. Known also as mobile or ubiquitous faults, their presence makes many t...

    Stefan Dobrev, Rastislav Královič in Structural Information and Communication C… (2006)

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    Chapter and Conference Paper

    Local Edge Colouring of Yao-Like Subgraphs of Unit Disk Graphs

    The focus of the present paper is on providing a local deterministic algorithm for colouring the edges of Yao-like subgraphs of Unit Disc Graphs. These are geometric graphs such that for some positive integers l,

    Jurek Czyzowicz, Stefan Dobrev in Structural Information and Communication C… (2007)

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    Chapter and Conference Paper

    Black Hole Search in Directed Graphs

    We consider the problem of cooperative network exploration by agents under the assumption that there is a harmful host present in the network that destroys the incoming agents without outside trace – the so-ca...

    Jurek Czyzowicz, Stefan Dobrev in Structural Information and Communication C… (2010)

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    Chapter and Conference Paper

    More Efficient Periodic Traversal in Anonymous Undirected Graphs

    We consider the problem of periodic graph exploration in which a mobile entity with (at most) constant memory, an agent, has to visit all n nodes of an arbitrary undirected graph G in a periodic manner. Graphs ar...

    Jurek Czyzowicz, Stefan Dobrev in Structural Information and Communication C… (2010)

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    Chapter and Conference Paper

    Routing in Carrier-Based Mobile Networks

    The past years have seen an intense research effort directed at study of delay/disruption tolerant networks and related concepts (intermittently connected networks, opportunistic mobility networks). As a funda...

    Bronislava Brejová, Stefan Dobrev in Structural Information and Communication C… (2011)

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    Chapter and Conference Paper

    Optimal Sensor Networks for Area Monitoring Using Rotating and Beam Sensors

    We consider the problem of monitoring the Euclidean plane using rotating sensors with detection sectors and beam sensors. We assume that intruders can appear anywhere at any time and move arbitrarily fast, and...

    Stefan Dobrev, Lata Narayanan, Jaroslav Opatrny in Fun with Algorithms (2012)

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    Chapter and Conference Paper

    Online Graph Exploration with Advice

    We study the problem of exploring an unknown undirected graph with non-negative edge weights. Starting at a distinguished initial vertex s, an agent must visit every vertex of the graph and return to s. Upon visi...

    Stefan Dobrev, Rastislav Královič in Structural Information and Communication C… (2012)

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    Chapter and Conference Paper

    Asynchronous Exploration of an Unknown Anonymous Dangerous Graph with O(1) Pebbles

    We consider the a team of asynchronous agents that must explore an unknown graph in presence of a black hole, a node which destroys all incoming agents without leaving any observable trace. Communication is ac...

    Balasingham Balamohan, Stefan Dobrev in Structural Information and Communication C… (2012)

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    Chapter and Conference Paper

    Complexity of Barrier Coverage with Relocatable Sensors in the Plane

    We consider several variations of the problems of covering a set of barriers (modeled as line segments) using sensors that can detect any intruder crossing any of the barriers. Sensors are initially located in...

    Stefan Dobrev, Stephane Durocher, Mohsen Eftekhari in Algorithms and Complexity (2013)

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    Chapter and Conference Paper

    Survivability of Swarms of Bouncing Robots

    Bouncing robots are mobile agents with limited sensing capabilities adjusting their movements upon collisions either with other robots or obstacles in the environment. They behave like elastic particles slidin...

    Jurek Czyzowicz, Stefan Dobrev, Evangelos Kranakis in LATIN 2014: Theoretical Informatics (2014)

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    Chapter and Conference Paper

    Searching for a Non-adversarial, Uncooperative Agent on a Cycle

    Assume k robots are placed on a cycle–the perimeter of a unit (radius) disk–at a position of our choosing and can move on the cycle with maximum speed 1. A non-adversarial, uncooperative agent, called bus, is mov...

    Jurek Czyzowicz, Stefan Dobrev, Maxime Godon in Algorithms for Sensor Systems (2017)

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    Chapter and Conference Paper

    Weak Coverage of a Rectangular Barrier

    Assume n wireless mobile sensors are initially dispersed in an ad hoc manner in a rectangular region. They are required to move to final locations so that they can detect any intruder crossing the region in a dir...

    Stefan Dobrev, Evangelos Kranakis, Danny Krizanc in Algorithms and Complexity (2017)