Oscar

1. Òscar Celma

Music Recommendation and Discovery

As the cost to create and distribute recorded music has dropped, the amount of available music has grown dramatically. Twenty years ago a typical record store would have music by less than ten thousand artists, while today online music stores have music catalogs by nearly a million artists.

1. Oscar Levin

Discrete Mathematics

Developments in Language Theory

This book constitutes the refereed proceedings of the 16th International Conference on Developments in Language Theory, DLT 2012, held in Taipei, Taiwan, in August 2012. The 34 regular papers presented were carefully reviewed and selected from numerous submissions. The volume also contains the papers or extended abstracts of 4 invited lectures, as well as a special memorial presentation in honor of Sheng Yu. The topics covered include grammars, acceptors and transducers for words, trees and graphs; algebraic theories of automata; algorithmic, combinatorial and algebraic properties of words and languages; variable length codes; symbolic dynamics; cellular automata; polyominoes and multidimensional patterns; decidability questions; image manipulation and compression; efficient text algorithms; relationships to cryptography, concurrency, complexity theory and logic; bio-inspired computing; quantum computing.

Computing and Combinatorics

Invited Lectures.- The Assembly of the Human and Mouse Genomes.- Data Structures for One-Dimensional Packet Classification Using Most-Specific-Rule Matching.- DNA Complementarity and Paradigms of Computing.- Complexity Theory I.- On Higher Arthur-Merlin Classes.- (2 + f(n))-SAT and Its Properties.- On the Minimal Polynomial of a Matrix.- Computable Real Functions of Bounded Variation and Semi-computable Real Numbers.- Discrete Algorithms I.- Improved Compact Routing Tables for Planar Networks via Orderly Spanning Trees.- Coloring Algorithms on Subcubic Graphs.- Efficient Algorithms for the Hamiltonian Problem on Distance-Hereditary Graphs.- Extending the Accommodating Function.- Computational Biology and Learning Theory I.- Inverse Parametric Sequence Alignment.- The Full Steiner Tree Problem in Phylogeny.- Inferring a Union of Halfspaces from Examples.- Dictionary Look-Up within Small Edit Distance.- Coding Theory and Cryptography.- Polynomial Interpolation of the Elliptic Curve and XTR Discrete Logarithm.- Co-orthogonal Codes.- Efficient Power-Sum Systolic Architectures for Public-Key Cryptosystems in GF(2m).- A Combinatorial Approach to Anonymous Membership Broadcast.- Parallel and Distributed Architectures.- Solving Constraint Satisfaction Problems with DNA Computing.- New Architecture and Algorithms for Degradable VLSI/WSI Arrays.- Cluster: A Fast Tool to Identify Groups of Similar Programs.- Broadcasting in Generalized de Bruijn Digraphs.- Graph Theory.- On the Connected Domination Number of Random Regular Graphs.- On the Number of Minimum Cuts in a Graph.- On Crossing Numbers of 5-Regular Graphs.- Maximum Flows and Critical Vertices in AND/OR Graphs.- Radio Networks.- New Energy-Efficient Permutation Routing Protocol for Single-Hop Radio Networks.- Simple MutualExclusion Algorithms Based on Bounded Tickets on the Asynchronous Shared Memory Model.- Time and Energy Optimal List Ranking Algorithms on the k-Channel Broadcast Communication Model.- Energy-Efficient Size Approximation of Radio Networks with No Collision Detection.- Automata and Formal Languages.- A New Class of Symbolic Abstract Neural Nets: Tissue P Systems.- Transducers with Set Output.- Self-assembling Finite Automata.- Repetition Complexity of Words.- Internet Networks.- Using PageRank to Characterize Web Structure.- On Randomized Broadcasting and Gossiping in Radio Networks.- Fast and Dependable Communication in Hyper-rings.- Computational Geometry I.- The On-Line Heilbronn's Triangle Problem in Three and Four Dimensions.- Algorithms for Normal Curves and Surfaces.- Terrain Polygon Decomposition, with Application to Layered Manufacturing.- Computational Biology and Learning Theory II.- Supertrees by Flipping.- A Space and Time Efficient Algorithm for Constructing Compressed Suffix Arrays.- Sharpening Occam's Razor.- Approximating 3D Points with Cylindrical Segments.- Discrete Algorithms II.- Algorithms for the Multicolorings of Partial k-Trees.- A Fault-Tolerant Merge Sorting Algorithm.- 2-Compromise Usability in 1-Dimensional Statistical Databases.- Computational Geometry II.- An Experimental Study and Comparison of Topological Peeling and Topological Walk.- On-Line Maximizing the Number of Items Packed in Variable-Sized Bins.- On-Line Grid-Packing with a Single Active Grid.- Bend Minimization in Orthogonal Drawings Using Integer Programming.- Combinatorial Optimization.- The Conditional Location of a Median Path.- New Results on the k-Truck Problem.- Theory of Equal-Flows in Networks.- Minimum Back-Walk-Free Latency Problem.- Complexity II.- CountingSatisfying Assignments in 2-SAT and 3-SAT.- On the Maximum Number of Irreducible Coverings of an n-Vertex Graph by n - 3 Cliques.- On Reachability in Graphs with Bounded Independence Number.- On Parameterized Enumeration.- Quantum Computing.- Probabilistic Reversible Automata and Quantum Automata.- Quantum versus Deterministic Counter Automata.- Quantum DNF Learnability Revisited.

Algorithms and Computation

Invited Presentation.- The Discrepancy Method.- Implementing Algorithms and Data Structures: An Educational and Research Perspective.- Geometry I.- L? Voronoi Diagrams and Applications to VLSI Layout and Manufacturing.- Facility Location on Terrains.- Computing Weighted Rectilinear Median and Center Set in the Presence of Obstacles.- Complexity I.- Maximizing Agreement with a Classification by Bounded or Unbounded number of Associated Words.- Disjunctions of Horn Theories and Their Cores.- Checking Programs Discreetly: Demonstrating Result-Correctness Efficiently While Concealing It.- Graph Drawing.- Two-Layer Planarization in Graph Drawing.- Computing Orthogonal Drawings in a Variable Embedding Setting.- Dynamic Grid Embedding with Few Bends and Changes.- On-Line Algorithm and Scheduling.- Two New Families of List Update Algorithms.- An Optimal Algorithm for On-Line Palletizing at Delivery Industry.- On-Line Scheduling of Parallel Jobs with Runtime Restrictions.- CAD/CAM and Graphics.- Testing the Quality of Manufactured Disks and Cylinders.- Casting with Skewed Ejection Direction.- Repairing Flaws in a Picture Based on a Geometric Representation of a Digital Image.- Graph Algorithm I.- k-Edge and 3-Vertex Connectivity Augmentation in an Arbitrary Multigraph.- Polyhedral Structure of Submodular and Posi-modular Systems.- Maximizing the number of Connections in Optical Tree Networks.- Best Paper Presentation.- Selecting the k Largest Elements with Parity Tests.- Randomized Algorithm.- Randomized K-Dimensional Binary Search Trees.- Randomized O(log log n)-Round Leader Election Protocols in Packet Radio Networks.- Random Regular Graphs with Edge Faults: Expansion through Cores.- Complexity II.- A Quantum Polynomial Time Algorithm in Worst Case for Simon's Problem.-Generalized Graph Colorability and Compressibility of Boolean Formulae.- On the Complexity of Free Monoid Morphisms.- Graph Algorithm II.- Characterization of Efficiently Solvable Problems on Distance-Hereditary Graphs.- Fast Algorithms for Independent Domination and Efficient Domination in Trapezoid Graphs.- Finding Planar Geometric Automorphisms in Planar Graphs.- Combinatorial Problem.- New Approach for Speeding Up Enumeration Algorithms.- Hamiltonian Decomposition of Recursive Circulants.- Convertibility among Grid Filling Curves.- Geometry II.- Generalized Self-Approaching Curves.- The Steiner Tree Problem in ?4-geometry Plane.- Computational Biology.- Approximation and Exact Algorithms for RNA Secondary Structure Prediction and Recognition of Stochastic Context-Free Languages.- On the Multiple Gene Duplication Problem.- Geometry III.- Visibility Queries in Simple Polygons and Applications.- Quadtree Decomposition, Steiner Triangulation, and Ray Shooting.- Optimality and Integer Programming Formulations of Triangulations in General Dimension.- Approximation Algorithm.- Space-Efficient Approximation Algorithms for MAXCUT and COLORING Semidefinite Programs.- A Capacitated Vehicle Routing Problem on a Tree.- Approximation Algorithms for Some Optimum Communication Spanning Tree Problems.- Complexity III.- The Edge-Disjoint Paths Problem is NP-Complete for Partial k-Trees.- Inapproximability Results for Guarding Polygons without Holes.- The Inapproximability of Non NP-hard Optimization Problems.- Parallel and Distributed Algorithm.- An Efficient NC Algorithm for a Sparse k-Edge-Connectivity Certificate.- A Parallel Algorithm for Sampling Matchings from an Almost Uniform Distribution.- Optimal Approximate Agreement with Omission Faults.

Developments in Language Theory

Invited Lectures.- Adding Nesting Structure to Words.- Can Abstract State Machines Be Useful in Language Theory?.- Languages in Membrane Computing: Some Details for Spiking Neural P Systems.- Computational Nature of Biochemical Reactions.- Papers.- Polynomials, Fragments of Temporal Logic and the Variety DA over Traces.- Weighted Automata and Weighted Logics on Infinite Words.- Simulation Relations for Alternating Parity Automata and Parity Games.- Equivalence of Functions Represented by Simple Context-Free Grammars with Output.- On the Gap-Complexity of Simple RL-Automata.- Noncanonical LALR(1) Parsing.- Context-Free Grammars and XML Languages.- Synchronization of Pushdown Automata.- Context-Dependent Nondeterminism for Pushdown Automata.- Prime Decompositions of Regular Languages.- On Weakly Ambiguous Finite Transducers.- Ciliate Bio-operations on Finite String Multisets.- Characterizing DNA Bond Shapes Using Trajectories.- Involution Solid and Join Codes.- Well-Founded Semantics for Boolean Grammars.- Hierarchies of Tree Series Transformations Revisited.- Bag Context Tree Grammars.- Closure of Language Classes Under Bounded Duplication.- The Boolean Closure of Growing Context-Sensitive Languages.- Well Quasi Orders and the Shuffle Closure of Finite Sets.- The Growth Ratio of Synchronous Rational Relations Is Unique.- On Critical Exponents in Fixed Points of Non-erasing Morphisms.- P Systems with Proteins on Membranes and Membrane Division.- Computing by Only Observing.- A Decision Procedure for Reflexive Regular Splicing Languages.- Contextual Hypergraph Grammars - A New Approach to the Generation of Hypergraph Languages.- End-Marked Maximal Depth-First Contextual Grammars.- Some Examples of Semi-rational DAG Languages.- Finding Lower Bounds for NondeterministicState Complexity Is Hard.- Lowering Undecidability Bounds for Decision Questions in Matrices.- Complexity of Degenerated Three Dimensional Billiard Words.- Factorial Languages of Low Combinatorial Complexity.- Perfect Correspondences Between Dot-Depth and Polynomial-Time Hierarchy.- Language Equations with Complementation.- Synchronizing Automata with a Letter of Deficiency 2.- On Some Variations of Two-Way Probabilistic Finite Automata Models.