Dynamic Data Structures for Document Collections and Graphs

In the dynamic indexing problem, we must maintain a changing collection of text documents so that we can efficiently support insertions, deletions, and pattern matching queries. We are especially interested in developing efficient data structures that store and query the documents in compressed form. All previous compressed solutions to this problem rely on answering rank and select queries on a dynamic sequence of symbols. Because of the lower bound in [Fredman and Saks, 1989], answering rank queries presents a bottleneck in compressed dynamic indexing. In this paper we show how this lower bound can be circumvented using our new framework. We demonstrate that the gap between static and dynamic variants of the indexing problem can be almost closed. Our method is based on a novel framework for adding dynamism to static compressed data structures. Our framework also applies more generally to dynamizing other problems. We show, for example, how our framework can be applied to develop compressed representations of dynamic graphs and binary relations

Building Vibrant Lives and Communities Through Higher Education

This essay examines the powerful impact that higher education has on changing lives, communities, and the world; how it creates opportunities, inspires new ideas, spurs innovations, and is the great enabler that allows people to create better futures. The essay provides illustrative examples from the University of Mississippi across a broad spectrum of areas. First, the essay examines how higher education offers a range of opportunities from inspiring and challenging the most prepared students to providing an accessible and affordable education to all qualifying students. The essay then describes how a modern university’s vision transcends the intellectual development of students and assumes the role of being an agent of change in the greater community. This change takes many forms including healthcare, economic development, education outreach, community service, and entrepreneurship. It also describes the key role that higher education plays in bettering communities through the nurturing of diversity. Finally, the essay emphasizes the importance of continually striving to make learning environments greater and educating students — tomorrow’s leaders — to prosper in a global society. It concludes that one of the greatest callings in life is to make the lives of others better and that higher education is uniquely positioned to transform lives and communities — from across the street to across the globe

Online Data Structures in External Memory

The original publication is available at www.springerlink.comThe data sets for many of today's computer applications are too large to t within the computer's internal memory and must instead be stored on external storage devices such as disks. A major performance bottleneck can be the input/output communication (or I/O) between the external and internal memories. In this paper we discuss a variety of online data structures for external memory, some very old and some very new, such as hashing (for dictionaries), B-trees (for dictionaries and 1-D range search), bu er trees (for batched dynamic problems), interval trees with weight-balanced B-trees (for stabbing queries), priority search trees (for 3-sided 2-D range search), and R-trees and other spatial structures. We also discuss several open problems along the way