Top | Bio | Research Interests | Publications | Reseach Project | Software Release | On-Line Tutorial | Conf. Organization | Talks | Teaching | Contact

Uzi Vishkin

- Professor, Univ. of Md Institute for Advanced Computer Studies (UMIACS) and
Department of Electrical and Computer Engineering
- Affiliate Professor, Department of Computer Science. See, the Algorithms and Theory Group


Education

  • D.Sc., Computer Science, Technion - Israel Institute of Technology (Haifa, Israel), 1981
  • M.Sc., Mathematics, Hebrew University (Jerusalem, Israel), 1975
  • B.Sc., Mathematics, Hebrew University (Jerusalem, Israel), 1974

Organization


Top | Bio | Research Interests | Publications | Reseach Project | Software Release | On-Line Tutorial | Conf. Organization | Talks | Teaching | Contact

Research Interests

Non-technical introduction

Overview: Uzi Vishkin's research aspirations evolved over the years from that of a parallel algorithms theory specialist to more of a generalist.

Still, a listing of technical areas and some elaboration follow:
  • Parallelism in computing
  • Design and analysis of algorithms.
  • Synergy of algorithms, programming and architecture for an easy-to-program general-purpose parallel computer platform.

    The premise that inspired his work in the last few years on the PRAM-On-Chip framework has been: Were the architecture component of PRAM-On-Chip feasible in the 1990s, its parallel programming component would have become the mainstream standard.

    In 1979 Uzi Vishkin identified the combined issue of parallel algorithms, parallel algorithmic thinking and programmability as the most critical component in developing a successful general-purpose parallel computer architecture. It simply did not look practical to proceed with building parallel computers before establishing a first satisfactory draft of its specifications. Such specifications had to include how to think about programming the computer to be built.

    Many, including Uzi Vishkin, spent the next 15-20 years on parallel algorithmics. In fact, during the 1980s and the early 1990s, quite a few very talented computer science researchers worked on the following wider problem: Seek the "ultimate" parallel programming model that will allow easy expression of parallel algorithms and their programs in the model, as well as validation of the model by algorithmic paradigms and solutions for as many problems as possible. In this fierce "battle of ideas", the one approach that has beaten all its competitors by a truly wide margin was the PRAM approach. As early as 1988, standard algorithms textbooks started including significant chapters on PRAM algorithms, and as the above premise suggests, PRAM algorithms were on their way to become standard computer science know-how that every computer science graduate must command and the basis for standard parallel programming. However, multi-chip multi-processing architectures provided the only form of multi-processing available in the 1990s. They required high coordination overhead, which prevented PRAM algorithms from providing an effective abstraction for them. As a result, it became common wisdom that "PRAM algorithms are unrealistic", leading later editions of some textbooks to remove their PRAM chapters.

    The good news are that the PRAM-On-Chip effort is finally establishing that it is becoming feasible to build a parallel computer that can be effectively programmed by a PRAM-like language.

    From today's perspective, the prospects for making the PRAM approach a standard for parallel algorithms and programming look pretty good: (i) "Darwin has already spoken" - see the natural selection that already happened in what was called above the battle of ideas; (ii) The inclusion of significant PRAM chapters in standard textbooks, before concerns about implementability prevailed; but (iii) These concerns are becoming less and less relevant as the PRAM-On-Chip project, with its extensive hardware prototyping, continues its progress.

    The optimistic tone above should not hide the fact that a significant research effort is still underway.

  • Pattern matching.
  • Theory of computing. In fact, the theory-driven PRAM-On-Chip effort aspires to provide a nice example where a forward looking theory-driven approach has practical impact.

Top | Bio | Research Interests | Publications | Reseach Project | Software Release | On-Line Tutorial | Conf. Organization | Talks | Teaching | Contact

Publications

Research Project

Software Release

Tutorial

  • On-Line Tutorial . Our recent public software release allows you to use your computer for programming on an XMT environment

Top | Bio | Research Interests | Publications | Reseach Project | Software Release | On-Line Tutorial | Conf. Organization | Talks | Teaching | Contact

Conference Organization

Old Talks

  • For more talks see the PRAM-On-Chip home page

Teaching

[ This is a link to suggestions on teaching parallelism as a theory-type algorithms course coupled with programming assignments. We provide all the material needed for a course on parallel algorithms coupled with XMTC programming assignments: video-recorded lectures for the full semester, class notes, dry homework assignments, and programming assignments along with a complete software environment, based on our recent public software release. It allows students to use their private computers for programming on an XMT environment. Lance Fortnow's recent blog postings The Revenge of Parallelism and Teaching Parallelism provide a helpful discussion thread. ]

Interesting Teaching-Related Links

Personal Links

Statement Against Boycott

Mailing Address:

Uzi Vishkin
University of Maryland Institute for Advanced Computer Studies (UMIACS)
A.V. Williams Building. Room 2365
College Park, MD 20742-3251

Phone: (301) 405-6763
email: x at umd.edu, where x is the last name

Top | Bio | Research Interests | Publications | Reseach Project | Software Release | On-Line Tutorial | Conf. Organization | Talks | Teaching | Contact