715,651 research outputs found
Solving the At-Most-Once Problem with Nearly Optimal Effectiveness
We present and analyze a wait-free deterministic algorithm for solving the
at-most-once problem: how m shared-memory fail-prone processes perform
asynchronously n jobs at most once. Our algorithmic strategy provides for the
first time nearly optimal effectiveness, which is a measure that expresses the
total number of jobs completed in the worst case. The effectiveness of our
algorithm equals n-2m+2. This is up to an additive factor of m close to the
known effectiveness upper bound n-m+1 over all possible algorithms and improves
on the previously best known deterministic solutions that have effectiveness
only n-log m o(n). We also present an iterative version of our algorithm that
for any is both
effectiveness-optimal and work-optimal, for any constant . We
then employ this algorithm to provide a new algorithmic solution for the
Write-All problem which is work optimal for any
.Comment: Updated Version. A Brief Announcement was published in PODC 2011. An
Extended Abstract was published in the proceeding of ICDCN 2012. A full
version was published in Theoretical Computer Science, Volume 496, 22 July
2013, Pages 69 - 8
The Turing Guide
This volume celebrates the various facets of Alan Turing (1912–1954), the British
mathematician and computing pioneer, widely considered as the father of computer
science. It is aimed at the general reader, with additional notes and references for those
who wish to explore the life and work of Turing more deeply.
The book is divided into eight parts, covering different aspects of Turing’s life and
work.
Part I presents various biographical aspects of Turing, some from a personal point of
view.
Part II presents Turing’s universal machine (now known as a Turing machine), which
provides a theoretical framework for reasoning about computation. His 1936 paper on this
subject is widely seen as providing the starting point for the field of theoretical computer
science.
Part III presents Turing’s working on codebreaking during World War II. While the War
was a disastrous interlude for many, for Turing it provided a nationally important outlet
for his creative genius. It is not an overstatement to say that without Turing, the War
would probably have lasted longer, and may even have been lost by the Allies. The
sensitive nature of Turning’s wartime work meant that much of this has been revealed
only relatively recently.
Part IV presents Turing’s post-War work on computing, both at the National Physical
Laboratory and at the University of Manchester. He made contributions to both hardware
design, through the ACE computer at the NPL, and software, especially at Manchester.
Part V covers Turing’s contribution to machine intelligence (now known as Artificial
Intelligence or AI). Although Turing did not coin the term, he can be considered a
founder of this field which is still active today, authoring a seminal paper in 1950.
Part VI covers morphogenesis, Turing’s last major scientific contribution, on the
generation of seemingly random patterns in biology and on the mathematics behind such
patterns. Interest in this area has increased rapidly in recent times in the field of
bioinformatics, with Turing’s 1952 paper on this subject being frequently cited.
Part VII presents some of Turing’s mathematical influences and achievements. Turing
was remarkably free of external influences, with few co-authors – Max Newman was an
exception and acted as a mathematical mentor in both Cambridge and Manchester.
Part VIII considers Turing in a wider context, including his influence and legacy to
science and in the public consciousness.
Reflecting Turing’s wide influence, the book includes contributions by authors from
a wide variety of backgrounds. Contemporaries provide reminiscences, while there are
perspectives by philosophers, mathematicians, computer scientists, historians of science,
and museum curators. Some of the contributors gave presentations at Turing Centenary
meetings in 2012 in Bletchley Park, King’s College Cambridge, and Oxford University,
and several of the chapters in this volume are based on those presentations – some
through transcription of the original talks, especially for Turing’s contemporaries, now
aged in their 90s. Sadly, some contributors died before the publication of this book, hence
its dedication to them.
For those interested in personal recollections, Chapters 2, 3, 11, 12, 16, 17, and 36
will be of interest. For philosophical aspects of Turing’s work, see Chapters 6, 7, 26–31,
and 41. Mathematical perspectives can be found in Chapters 35 and 37–39. Historical
perspectives can be found in Chapters 4, 8, 9, 10, 13–15, 18, 19, 21–25, 34, and 40. With
respect to Turing’s body of work, the treatment in Parts II–VI is broadly chronological.
We have attempted to be comprehensive with respect to all the important aspects of
Turing’s achievements, and the book can be read cover to cover, or the chapters can be
tackled individually if desired. There are cross-references between chapters where
appropriate, and some chapters will inevitably overlap.
We hope that you enjoy this volume as part of your library and that you will dip into
it whenever you wish to enter the multifaceted world of Alan Turing
A Survey on Continuous Time Computations
We provide an overview of theories of continuous time computation. These
theories allow us to understand both the hardness of questions related to
continuous time dynamical systems and the computational power of continuous
time analog models. We survey the existing models, summarizing results, and
point to relevant references in the literature
Benchmarks for Parity Games (extended version)
We propose a benchmark suite for parity games that includes all benchmarks
that have been used in the literature, and make it available online. We give an
overview of the parity games, including a description of how they have been
generated. We also describe structural properties of parity games, and using
these properties we show that our benchmarks are representative. With this work
we provide a starting point for further experimentation with parity games.Comment: The corresponding tool and benchmarks are available from
https://github.com/jkeiren/paritygame-generator. This is an extended version
of the paper that has been accepted for FSEN 201
The view from elsewhere: perspectives on ALife Modeling
Many artificial life researchers stress the interdisciplinary character of the field. Against such a backdrop, this report reviews and discusses artificial life, as it is depicted in, and as it interfaces with, adjacent disciplines (in particular, philosophy, biology, and linguistics), and in the light of a specific historical example of interdisciplinary research (namely cybernetics) with which artificial life shares many features. This report grew out of a workshop held at the Sixth European Conference on Artificial Life in Prague and features individual contributions from the workshop's eight speakers, plus a section designed to reflect the debates that took place during the workshop's discussion sessions. The major theme that emerged during these sessions was the identity and status of artificial life as a scientific endeavor
Two Decades of Maude
This paper is a tribute to José Meseguer, from the rest of us in the Maude team, reviewing the past, the present, and the future of the language and system with which we have been working for around two decades under his leadership. After reviewing the origins and the language's main features, we present the latest additions to the language and some features currently under development. This paper is not an introduction to Maude, and some familiarity with it and with rewriting logic are indeed assumed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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