Sebastiano Vigna

Last updated

Sebastiano Vigna (born 1967) [1] is a professor of computer science at the University of Milan. [2] He created the xorshift+ and xoroshiro128+ pseudorandom number generators. Xorshift128+ is used in the JavaScript engines of Chrome, Firefox, and Safari. [3] [4] In 1991, he received a laurea in Mathematics and in 1996 a Ph.D. in computer science; both from the University of Milan. He developed UbiCrawler, a web crawler, in a collaboration with others. [2] [5]

He worked extensively on graph algorithms such as HyperBall. [6] He used this algorithm, together with researchers from Facebook and others, to compute the degrees of separation on the global Facebook network, which resulted in an average distance of 4.74. [7]

Related Research Articles

<span class="mw-page-title-main">Web crawler</span> Software which systematically browses the World Wide Web

A Web crawler, sometimes called a spider or spiderbot and often shortened to crawler, is an Internet bot that systematically browses the World Wide Web and that is typically operated by search engines for the purpose of Web indexing.

<span class="mw-page-title-main">Perfect hash function</span> Hash function without any collisions

In computer science, a perfect hash functionh for a set S is a hash function that maps distinct elements in S to a set of m integers, with no collisions. In mathematical terms, it is an injective function.

<span class="mw-page-title-main">University of Pavia</span> Public university in Pavia, Italy

The University of Pavia is a university located in Pavia, Lombardy, Italy. There was evidence of teaching as early as 1361, making it one of the oldest universities in the world. It was the sole university in Milan and the greater Lombardy region until the end of the 19th century. In 2022 the university was recognized by the Times Higher Education among the top 10 in Italy and among the 300 best in the world. Currently, it has 18 departments and 9 faculties. It does not have a main campus; its buildings and facilities are scattered around the city, which is in turn called "a city campus." The university caters to more than 20,000 students who come from Italy and all over the world.

<span class="mw-page-title-main">Search engine</span> Software system that is designed to search for information on the World Wide Web

A web search engine is a software system that finds web pages that match a web search. It searches the World Wide Web in a systematic way for particular information specified in a textual web search query. The search results are generally presented in a line of results, often referred to as search engine results pages (SERPs). The information may be a mix of hyperlinks to web pages, images, videos, infographics, articles, and other types of files. As of January 2022, Google is by far the world's most used search engine, with a market share of 90.6%, and the world's other most used search engines were Bing, Yahoo!, Baidu, Yandex, and DuckDuckGo.

<span class="mw-page-title-main">Sebastiano Rossi</span> Italian footballer

Sebastiano Rossi is an Italian retired professional footballer who played as a goalkeeper.

<span class="mw-page-title-main">Zvi Galil</span> Israeli mathematician and computer scientist

Zvi Galil is an Israeli-American computer scientist and mathematician. Galil served as the president of Tel Aviv University from 2007 through 2009. From 2010 to 2019, he was the dean of the Georgia Institute of Technology College of Computing. His research interests include the design and analysis of algorithms, computational complexity and cryptography. He has been credited with coining the terms stringology and sparsification. He has published over 200 scientific papers and is listed as an ISI highly cited researcher.

<span class="mw-page-title-main">Damiano Damiani</span> Italian screenwriter, film director, actor and writer

Damiano Damiani was an Italian screenwriter, film director, actor and writer. Poet and director Pier Paolo Pasolini referred to him as "a bitter moralist hungry for old purity", while film critic Paolo Mereghetti said that his style made him "the most American of Italian directors".

<span class="mw-page-title-main">Xorshift</span> Class of pseudorandom number generators

Xorshift random number generators, also called shift-register generators, are a class of pseudorandom number generators that were invented by George Marsaglia. They are a subset of linear-feedback shift registers (LFSRs) which allow a particularly efficient implementation in software without the excessive use of sparse polynomials. They generate the next number in their sequence by repeatedly taking the exclusive or of a number with a bit-shifted version of itself. This makes execution extremely efficient on modern computer architectures, but it does not benefit efficiency in a hardware implementation. Like all LFSRs, the parameters have to be chosen very carefully in order to achieve a long period.

<span class="mw-page-title-main">Georg Gottlob</span> Austrian computer scientist

Georg Gottlob FRS is an Austrian-Italian computer scientist who works in the areas of database theory, logic, and artificial intelligence and is Professor of Informatics at the University of Calabria. He was Professor at the University of Oxford.

Jayme Luiz Szwarcfiter is a computer scientist in Brazil.

<span class="mw-page-title-main">Peter O'Hearn</span> Research scientist (born 1963)

Peter William O'Hearn, formerly a research scientist at Meta, is a Distinguished Engineer at Lacework and a Professor of Computer science at University College London (UCL). He has made significant contributions to formal methods for program correctness. In recent years these advances have been employed in developing industrial software tools that conduct automated analysis of large industrial codebases.

The webgraph describes the directed links between pages of the World Wide Web. A graph, in general, consists of several vertices, some pairs connected by edges. In a directed graph, edges are directed lines or arcs. The webgraph is a directed graph, whose vertices correspond to the pages of the WWW, and a directed edge connects page X to page Y if there exists a hyperlink on page X, referring to page Y.

<span class="mw-page-title-main">Noam Nisan</span> Israeli computer scientist

Noam Nisan is an Israeli computer scientist, a professor of computer science at the Hebrew University of Jerusalem. He is known for his research in computational complexity theory and algorithmic game theory.

Nivio Ziviani, a Brazilian researcher born in the city of Belo Horizonte on August 27, 1946, holds a bachelor's degree in mechanical engineering from the Federal University of Minas Gerais, 1971, a master's degree in informatics from the Pontifical Catholic University of Rio de Janeiro, 1976, and a Ph.D. degree in computer science from the University of Waterloo, 1982. As a researcher, he is known for his projects in information retrieval and recommendation systems. In 2011, he received the Scientific Merit Award from the Brazilian Computer Society. Ziviani has Erdös number 2. Currently, he is an emeritus professor in the Computer Science department of the Federal University of Minas Gerais, is a member of the Brazilian Academy of Sciences, he is part of the National Order of Scientific Merit in the Commendator class, and coordinates the Laboratory for Treating Information (LATIN).

Sebastiano Vassalli was an Italian author. He wrote the 2007 novel The Italian (L'italiano).

<span class="mw-page-title-main">Six degrees of separation</span> Concept of social inter-connectedness of all people

Six degrees of separation is the idea that all people are six or fewer social connections away from each other. As a result, a chain of "friend of a friend" statements can be made to connect any two people in a maximum of six steps. It is also known as the six handshakes rule.

Emilio Villa was an Italian poet, visual artist, translator, art critic and Bible scholar. His poems reflected his knowledge of modern and ancient languages, including Italian, French, English, Latin, Greek, Hebrew, Sumerian, and Akkadian.

In computer science, SimHash is a technique for quickly estimating how similar two sets are. The algorithm is used by the Google Crawler to find near duplicate pages. It was created by Moses Charikar. In 2021 Google announced its intent to also use the algorithm in their newly created FLoC system.

<span class="mw-page-title-main">Salvatore Aranzulla</span> Italian blogger and entrepreneur

Salvatore Aranzulla is an Italian blogger and entrepreneur. He is a well-known popularizer and author of problem solving tutorials for information technology by the general Italian public.

<span class="mw-page-title-main">Paolo Benanti</span> Italian priest and theologian

Paolo Benanti, TOR is an Italian Catholic priest, theologian and academic. He is a member of the Third Order Regular of St. Francis. He teaches at the Pontifical Gregorian University and is advisor to Pope Francis on issues of artificial intelligence and technology ethics.

References

  1. "Sebastiano Vigna CURRICULUM VITAE" (PDF).
  2. 1 2 "Sebastiano Vigna". vigna.di.unimi.it.
  3. Giorno, Il (16 January 2016). "Il prof della Statale conquista la Silicon Valley con un algoritmo - Il Giorno".
  4. "Nuovo algoritmo: in arrivo per cellulari, tablet, pc di tutto mondo". 30 January 2016.
  5. Boldi, Paolo; Codenotti, Bruno; Santini, Massimo; Vigna, Sebastiano (July 10, 2004). "UbiCrawler: a scalable fully distributed Web crawler". Software: Practice and Experience. 34 (8): 711–726. CiteSeerX   10.1.1.2.5538 . doi:10.1002/spe.587. ISSN   1097-024X. S2CID   325714.
  6. Boldi, Paolo; Vigna, Sebastiano (2013). "In-Core Computation of Geometric Centralities with HyperBall: A Hundred Billion Nodes and Beyond". 2013 IEEE 13th International Conference on Data Mining Workshops. pp. 621–628. arXiv: 1308.2144 . doi:10.1109/ICDMW.2013.10. ISBN   978-1-4799-3142-2. S2CID   9744150.
  7. Barnett, Emma (22 November 2011). "Facebook cuts six degrees of separation to four". Telegraph. Retrieved 7 May 2012.