Lenwood S. Heath

Publications (13)0 Total impact

• Article: The PMU Placement Problem.

  Dennis J. Brueni, Lenwood S. Heath
  SIAM J. Discrete Math. 01/2005; 19:744-761.
• Article: Users, user interfaces, and objects: Envision, a digital library

  Edward A. Fox, Deborah Hix, Lucy T. Nowell, Dennis J. Brueni, William C. Wake, Lenwood S. Heath, Durgesh Rao
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  ABSTRACT: Project Envision aims to build a “user-centered database from the computer science literature,” initially using the publications of the Association for Computing Machinery (ACM). Accordingly, we have interviewed potential users, as well as experts in library, information, and computer science—to understand their needs, to become aware of their perception of existing information systems, and to collect their recommendations. Design and formative usability evaluation of our interface have been based on those interviews, leading to innovative query formulation and search results screens that work well according to our usability testing. Our development of the Envision database, system software, and protocol for client-server communication builds upon work to identify and represent “objects” that will facilitate reuse and high-level communication of information from author to reader (user). All these efforts are leading not only to a usable prototype digital library but also to a set of nine principles for digital libraries, which we have tried to follow, covering issues of representation, architecture, and interfacing. © 1993 John Wiley & Sons, Inc.
  Journal of the American Society for Information Science 01/1999; 44(8):480 - 491.
• Source

  Available from: psu.edu

  Conference Proceeding: Visualizing Search Results: Some Alternatives to Query-Document Similarity.

  Lucy T. Nowell, Robert K. France, Deborah Hix, Lenwood S. Heath, Edward A. Fox
  Proceedings of the 19th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, SIGIR'96, August 18-22, 1996, Zurich, Switzerland (Special Issue of the SIGIR Forum); 01/1996
• Article: Principal Investigators

  Edward A. Fox, Lenwood S. Heath, Deborah Hix, Durgesh Rao, Guillermo A. Averboch, Sangita Betrabet, Dennis J. Brueni, Laura M. Craighead, Kaushal Dalal, Fred L. Drake, [......], Tom Foy, Scott A. Guyer, Chris Kirmse, Stephen Moore, Eric A. Labow, Gregory W. Fox, Jeffrey D. Fox, Robert K. France, Nsf Grant, Iri- Fox
  [show abstract] [hide abstract]
  ABSTRACT: e University, 1994. [39] L. T. Nowell and D. Hix. User interface design for the project Envision database of computer science literature. In Proceedings of the Twenty-second Annual Virginia Computer Users Conference, pages 29--33, 1992. [40] L. T. Nowell and D. Hix. Query composition: Why does it have to be so hard? In Proceedings of the East-West International Conference on Human-Computer Interaction, volume I, pages 226--241, 1993. Moscow, Russia, August, 1993. Also available as Tech. Report TR 93-19, Department of Computer Science, Virginia Polytechnic Institute and State University. [41] L. T. Nowell and D. Hix. Visualizing search results: User interface development for the project Envision database of computer science literature. In Human-Computer Interaction: Software and Hardware Interfaces, volume 19B of Advances in Human Factors/Ergonomics, Proceedings of HCI International '93, 5th International Conference on Human Compu
  11/1995;
• Article: Envision: A User-Centered Database of Computer Science Literature.

  Lenwood S. Heath, Deborah Hix, Lucy T. Nowell, William C. Wake, Guillermo A. Averboch, Eric Labow, Scott A. Guyer, Dennis J. Brueni, Robert K. France, Kaushal Dalal, Edward A. Fox
  Commun. ACM. 01/1995; 38:52-53.
• Article: Users, User Interfaces, and Objects: Envision, a Digital Library.

  Edward A. Fox, Deborah Hix, Lucy T. Nowell, Dennis J. Brueni, William C. Wake, Lenwood S. Heath, Durgesh Rao
  JASIS. 01/1993; 44:480-491.
• Source

  Available from: vt.edu

  Conference Proceeding: What If There Were Desktop Access to the Computer Science Literature?

  Dennis J. Brueni, Baziley T. Cross, Edward A. Fox, Lenwood S. Heath, Deborah Hix, Lucy T. Nowell, William C. Wake
  01/1993
• Source

  Available from: psu.edu

  Conference Proceeding: A Faster Algorithm for Constructing Minimal Perfect Hash Functions.

  Edward A. Fox, Qi Fan Chen, Lenwood S. Heath
  Proceedings of the 15th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval. Copenhagen, Denmark, June 21-24, 1992; 01/1992
• Article: Practical Minimal Perfect Hash Functions for Large Databases.

  Edward A. Fox, Lenwood S. Heath, Qi Fan Chen, Amjad M. Daoud
  Commun. ACM. 01/1992; 35:105-121.
• Source

  Available from: citeseerx.ist.psu.edu

  Article: Order-Preserving Minimal Perfect Hash Functions and Information Retrieval.

  Edward A. Fox, Qi Fan Chen, Amjad M. Daoud, Lenwood S. Heath
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  ABSTRACT: Rapid access to information is essential for a wide variety of retrieval systems and applications. Hashing has long been used when the fastest possible direct search is desired, but is generally not appropriate when sequential or range searches are also required. This paper describes a hashing method, developed for collections that are relatively static, that supports both direct and sequential access. Indeed, the algorithm described gives hash functions that are optimal in terms of time and hash table space utilization, and that preserve any a priori ordering desired. Furthermore, the resulting order preserving minimal perfect hash functions (OPMPHFs) can be found using space and time that is on average linear in the number of keys involved.
  ACM Trans. Inf. Syst. 01/1991; 9:281-308.
• Source

  Available from: psu.edu

  Conference Proceeding: Order Preserving Minimal Perfect Hash Functions and Information Retrieval.

  Edward A. Fox, Qi Fan Chen, Amjad M. Daoud, Lenwood S. Heath
  SIGIR'90, 13th International Conference on Research and Development in Information Retrieval, Brussels, Belgium, 5-7 September 1990, Proceedings; 01/1990
• Source

  Available from: vt.edu

  Conference Proceeding: A More Cost Effective Algorithm for Finding Perfect Hash Functions.

  Edward A. Fox, Qi Fan Chen, Lenwood S. Heath, S. Datta
  01/1989
• Source

  Available from: eprints.cs.vt.edu

  Article: Representing polyhedra: faces are better than vertices

  Lenwood S. Heath, Praveen K. Paripati, John W. Roach
  [show abstract] [hide abstract]
  ABSTRACT: This paper investigates the reconstruction of planar-faced polyhedra given their spherical dual representation. The spherical dual representation for any genus 0 polyhedron is shown to be unambiguous and to be uniquely reconstructible in polynomial time. It is also shown that when the degree of the spherical dual representation is at most four, the representation is unambiguous for polyhedra of any genus. The first result extends, in the case of planar-faced polyhedra, the well known result that a vertex or face connectivity graph represents a polyhedron unambiguously when the graph is triconnected and planar. The second result shows that when each face of a polyhedron of arbitrary genus has at most four edges, the polyhedron can be reconstructed uniquely. This extends the previous result that a polyhedron can be uniquely reconstructed when each face of the polyhedron is triangular. As a consequence of this result, faces are a more powerful representation than vertices for polyhedra whose faces have three or four edges. A result of the reconstruction algorithm is that high level features of the polyhedron are naturally extracted. Both results explicitly use the fact that the faces of the polyhedron are planar. It is conjectured that the spherical dual representation is unambiguous for polyhedra of any genus.
  Computational Geometry.