The papers in this volume were selected for presentation at the Eleventh Annual International Symposium on Algorithms and Computation (ISAAC 2000), held on 18{20 December, 2000 at the Institute of Information Science, Academia Sinica, Taipei, Taiwan. Previous meetings were held in Tokyo (1990), Taipei (1991), Nagoya (1992), Hong Kong (1993), Beijing (1994), Cairns (1995), Osaka (1996), Singapore (1997), Taejon (1998), and Chennai (1999). Submissions to the conference this year were conducted entirely electro- cally. Thanks to the excellent software developed by the Institute of Information Science, Academia Sinica, we were able to carry out virtually all communication via the World Wide Web. In response to the call for papers, a total of 87 extended abstracts were submitted from 25 countries. Each submitted paper was handled by at least three program committee members, with the assistance of a number of external reviewers, as indicated by the referee list found in the proceedings. There were many more acceptable papers than there was space available in the symposium program, which made the program committee’s task extremely di cult. Finally 46 papers were selected for presentation at the Symposium. In addition to these contributed papers, the conference also included two invited presentations by Dr. Jean-Daniel Boissonnat, INRIA Sophia-Antipolis, France and Professor Jin-Yi Cai, University of Wisconsin at Madison, Wisconsin, USA. It is expected that most of the accepted papers will appear in a more complete form in scienti c journals.

Table of Contents:
Invited Presentations.- Voronoi-Based Systems of Coordinates and Surface Reconstruction.- Essentially Every Unimodular Matrix Defines an Expander.- Algorithms and Data Structures (I).- Strategies for Hotlink Assignments.- A New Competitive Analysis of Randomized Caching.- Online Routing in Convex Subdivisions.- Combinatorial Optimization.- A Simple Linear-Time Approximation Algorithm for Multi-processor Job Scheduling on Four Processors.- Classification of Various Neighborhood Operations for the Nurse Scheduling Problem.- Optimal Bid Sequences for Multiple-Object Auctions with Unequal Budgets.- Algorithms and Data Structures (II).- Coping with Delays and Time-Outs in Binary Search Procedures.- Some Formal Analysis of Rocchio’s Similarity-Based Relevance Feedback Algorithm.- Reasoning with Ordered Binary Decision Diagrams.- Approximation and Randomized Algorithms (I).- On Approximating Minimum Vertex Cover for Graphs with Perfect Matching.- A 2-Approximation Algorithm for Path Coloring on Trees of Rings.- An Approximate Algorithm for the Weighted Hamiltonian Path Completion Problem on a Tree.- Algorithms and Data Structures (III).- Finding Independent Spanning Trees in Partial k-Trees.- On Efficient Fixed Parameter Algorithms for Weighted Vertex Cover.- Constructive Linear Time Algorithms for Small Cutwidth and Carving-Width.- Approximation and Randomized Algorithms (II).- Approximation Algorithms for the Maximum Power Consumption Problem on Combinatorial Circuits.- A Simple and Quick Approximation Algorithm for Traveling Salesman Problem in the Plane.- Simple Algorithms for a Weighted Interval Selection Problem.- Graph Drawing and Algorithms.- Efficient Minus and Signed Domination in Graphs.- Convex Grid Drawings of Four-Connected Plane Graphs.- An Algorithm forFinding Three Dimensional Symmetry in Series Parallel Digraphs.- Automata, Cryptography, and Complexity Theory.- Undecidability Results for Monoids with Linear-Time Decidable Word Problems.- Secret Key Exchange Using Random Deals of Cards on Hierarchical Structures.- Derandomizing Arthur-Merlin Games under Uniform Assumptions.- Algorithms and Data Structures (IV).- A Near Optimal Algorithm for Vertex Connectivity Augmentation.- Simultaneous Augmentation of Two Graphs to an ?Edge-Connected Graph and a Biconnected Graph.- Location Problems Based on Node-Connectivity and Edge-Connectivity between Nodes and Node-Subsets.- Parallel and Distributed Algorithms.- An Intuitive and Effective New Representation for Interconnection Network Structures.- Randomized Leader Election Protocols in Radio Networks with no Collision Detection.- Deterministic Broadcasting Time with Partial Knowledge of the Network.- Algorithms and Data Structures (V).- Minimizing Makespan in Batch Machine Scheduling.- Preemptive Parallel Task Scheduling in O(n) + Poly(m) Time.- Compressed Text Databases with Efficient Query Algorithms Based on the Compressed Suffix Array.- Computational Geometry (I).- A Better Lower Bound for Two-Circle Point Labeling.- Voronoi Diagram of a Circle Set Constructed from Voronoi Diagram of a Point Set.- An Improved Algorithm for Subdivision Traversal without Extra Storage.- Algorithms and Data Structures (VI).- Generalized H-Coloring of Graphs.- Finding a Two-Core of a Tree in Linear Time.- Unbalanced and Hierarchical Bipartite Matchings with Applications to Labeled Tree Comparison.- Computational Geometry (II).- Optimal Beam Penetrations in Two and Three Dimensions.- Searching a Simple Polygon by a k-Searcher.- Characterization of Rooms Searchable by Two Guards.-Computational Biology.- Improved Phylogeny Comparisons: Non-shared Edges, Nearest Neighbor Interchanges, and Subtree Transfers.- Phylogenetic k-Root and Steiner k-Root.- Computational Geometry (III).- Maintenance of a Piercing Set for Intervals with Applications.- Optimal Polygon Cover Problems and Applications.