Obstruction Characterizations in Graphs and Digraphs -- Approximation Algorithms -- A PTAS for the Metric Case of the Minimum Sum-Requirement Communication Spanning Tree Problem -- Constant Approximation for Broadcasting in k-cycle Graph -- Computational Geometry -- Three paths to point placement -- Vertex Guarding in Weak Visibility Polygons -- On Collections of Polygons Cuttable with a Segment Saw -- Rectilinear path problems in the presences of rectangular obstacles -- Computational Complexity -- Parameterized Analogues of Probabilistic Computation -- Algebraic Expressions of Rhomboidal Graphs -- Solving Hamiltonian Cycle by an EPT Algorithm for a Non-sparse Parameter -- Graph Theory. New Polynomial Case for Efficient Domination in P 6-free Graphs -- Higher-Order Triangular-Distance Delaunay Graphs: Graph-Theoretical Properties -- Separator Theorems for Interval Graphs and Proper Interval Graphs -- Bounds for the b-Chromatic Number of Induced Subgraphs and G e -- New Characterizations Of Proper Interval Bigraphs and Proper Circular Arc Bigraphs -- On Spectra of Corona Graphs -- Axiomatic Characterization of the Median and Antimedian Functions on Cocktail-Party Graphs and Complete Graphs -- Tree Path Labeling of Hypergraphs A Generalization of the Consecutive Ones Property -- On a special class of boxicity 2 graph -- Algorithms -- Associativity for Binary Parallel Processes: a Quantitative Study -- A Tight Bound for Congestion of an Embedding.-Auction/Belief propagation algorithms for constrained assignment problem -- Domination in some subclasses of bipartite graphs -- Bi-directional Search for Skyline Probability -- Cumulative vehicle routing problem: a column generation approach -- Energy Efficient Sweep Coverage with Mobile and Static Sensors -- Generation of Random Digital Curves using Combinatorial Techniques.