Quantum Hypercomputation—Hype Or Computation?
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Software for Numerical Computation
Purdue University Purdue e-Pubs Department of Computer Science Technical Reports Department of Computer Science 1977 Software for Numerical Computation John R. Rice Purdue University, [email protected] Report Number: 77-214 Rice, John R., "Software for Numerical Computation" (1977). Department of Computer Science Technical Reports. Paper 154. https://docs.lib.purdue.edu/cstech/154 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. SOFTWARE FOR NUMERICAL COMPUTATION John R. Rice Department of Computer Sciences Purdue University West Lafayette, IN 47907 CSD TR #214 January 1977 SOFTWARE FOR NUMERICAL COMPUTATION John R. Rice Mathematical Sciences Purdue University CSD-TR 214 January 12, 1977 Article to appear in the book: Research Directions in Software Technology. SOFTWARE FOR NUMERICAL COMPUTATION John R. Rice Mathematical Sciences Purdue University INTRODUCTION AND MOTIVATING PROBLEMS. The purpose of this article is to examine the research developments in software for numerical computation. Research and development of numerical methods is not intended to be discussed for two reasons. First, a reasonable survey of the research in numerical methods would require a book. The COSERS report [Rice et al, 1977] on Numerical Computation does such a survey in about 100 printed pages and even so the discussion of many important fields (never mind topics) is limited to a few paragraphs. Second, the present book is focused on software and thus it is natural to attempt to separate software research from numerical computation research. This, of course, is not easy as the two are intimately intertwined. -
Mathematics and Computation
Mathematics and Computation Mathematics and Computation Ideas Revolutionizing Technology and Science Avi Wigderson Princeton University Press Princeton and Oxford Copyright c 2019 by Avi Wigderson Requests for permission to reproduce material from this work should be sent to [email protected] Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TR press.princeton.edu All Rights Reserved Library of Congress Control Number: 2018965993 ISBN: 978-0-691-18913-0 British Library Cataloging-in-Publication Data is available Editorial: Vickie Kearn, Lauren Bucca, and Susannah Shoemaker Production Editorial: Nathan Carr Jacket/Cover Credit: THIS INFORMATION NEEDS TO BE ADDED WHEN IT IS AVAILABLE. WE DO NOT HAVE THIS INFORMATION NOW. Production: Jacquie Poirier Publicity: Alyssa Sanford and Kathryn Stevens Copyeditor: Cyd Westmoreland This book has been composed in LATEX The publisher would like to acknowledge the author of this volume for providing the camera-ready copy from which this book was printed. Printed on acid-free paper 1 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 Dedicated to the memory of my father, Pinchas Wigderson (1921{1988), who loved people, loved puzzles, and inspired me. Ashgabat, Turkmenistan, 1943 Contents Acknowledgments 1 1 Introduction 3 1.1 On the interactions of math and computation..........................3 1.2 Computational complexity theory.................................6 1.3 The nature, purpose, and style of this book............................7 1.4 Who is this book for?........................................7 1.5 Organization of the book......................................8 1.6 Notation and conventions..................................... -
Alan Turing, Hypercomputation, Adam Smith and Next Generation Intelligent Systems
J. Intell. Syst. 21 (2012), 325–330 DOI 10.1515/jisys-2012-0017 © de Gruyter 2012 Something Old, Something New, Something Borrowed, Something Blue Part 1: Alan Turing, Hypercomputation, Adam Smith and Next Generation Intelligent Systems Mark Dougherty Abstract. In this article intelligent systems are placed in the context of accelerated Turing machines. Although such machines are not currently a reality, the very real gains in computing power made over previous decades require us to continually reevaluate the potential of intelligent systems. The economic theories of Adam Smith provide us with a useful insight into this question. Keywords. Intelligent Systems, Accelerated Turing Machine, Specialization of Labor. 2010 Mathematics Subject Classification. Primary 01-02, secondary 01A60, 01A67. 1 Introduction The editor-in-chief of this journal has asked me to write a series of shorter articles in which I try to illuminate various challenges in intelligent systems. Given space requirements they cannot be regarded as comprehensive reviews, they are intended to provide an overview and to be a point of departure for discussion and debate. The title of the series implies that I will look at both very old and rather new concepts and I will not be afraid to borrow from other subjects. Nor will I be afraid to incorporate radical “blue skies” ideas or hypotheses. By challenges I mean aspects of our subject which cannot easily be tackled by either theoretical means or through empirical enquiry. That may be because the questions raised are not researchable or because no evidence has yet been ob- served. Or it may be that work is underway but that no firm conclusions have yet been reached by the research community. -
Biological Computation: a Road
918 Biological Computation: A Road to Complex Engineered Systems Nelson Alfonso Gómez-Cruz Modeling and Simulation Laboratory Universidad del Rosario Bogotá, Colombia [email protected] Carlos Eduardo Maldonado Research Professor Universidad del Rosario Bogotá, Colombia [email protected] Provided that there is no theoretical frame for complex engineered systems (CES) as yet, this paper claims that bio-inspired engineering can help provide such a frame. Within CES bio- inspired systems play a key role. The disclosure from bio-inspired systems and biological computation has not been sufficiently worked out, however. Biological computation is to be taken as the processing of information by living systems that is carried out in polynomial time, i.e., efficiently; such processing however is grasped by current science and research as an intractable problem (for instance, the protein folding problem). A remark is needed here: P versus NP problems should be well defined and delimited but biological computation problems are not. The shift from conventional engineering to bio-inspired engineering needs bring the subject (or problem) of computability to a new level. Within the frame of computation, so far, the prevailing paradigm is still the Turing-Church thesis. In other words, conventional 919 engineering is still ruled by the Church-Turing thesis (CTt). However, CES is ruled by CTt, too. Contrarily to the above, we shall argue here that biological computation demands a more careful thinking that leads us towards hypercomputation. Bio-inspired engineering and CES thereafter, must turn its regard toward biological computation. Thus, biological computation can and should be taken as the ground for engineering complex non-linear systems. -
State of the Art of Information Technology Computing Models for Autonomic Cloud Computing †
Proceedings State of the Art of Information Technology Computing Models for Autonomic Cloud Computing † Eugene Eberbach Department of Computer Science and Robotics Engineering Program, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280, USA; [email protected]; Tel.: +1-508-831-4937 † Presented at the IS4SI 2017 Summit DIGITALISATION FOR A SUSTAINABLE SOCIETY, Gothenburg, Sweden, 12–16 June 2017. Published: 9 June 2017 Abstract: In the paper we present several models of computation for autonomic cloud computing. In particular, we justify that for autonomic cloud computing if we require perfect self-reflection, we need models of computation going beyond Turing machines. To approximate self-reflection, models below Turing machines are sufficient. The above claims are illustrated using as an example the DIME Network Architecture. Keywords: autonomic cloud computing; Turing machine; incompleteness; self-reflection; superTuring machines; DIME network architecture 1. Introduction A distributed system is a collection of independent computers that appears to its users as a single coherent system with basic characteristics: 1. concurrency of components, lack of a global clock, scalability and independent failures of components, 2. underlying transparency (inherited by cloud computing), hiding unnecessary details of management, networking, multi-computer implementation or services, 3. providing a uniform way of looking at the whole distributed system. We will consider two subclasses of distributed systems represented by cloud and autonomic computing. Cloud Computing is a relatively new concept in computing that emerged in the late 1990s and the 2000s (but having roots from 1960s—IBM VMs for System360/370/390), first under the name software as a service—the details of computing are hidden transparently in the networking “cloud” 1. -
Introduction to the Theory of Computation Computability, Complexity, and the Lambda Calculus Some Notes for CIS262
Introduction to the Theory of Computation Computability, Complexity, And the Lambda Calculus Some Notes for CIS262 Jean Gallier and Jocelyn Quaintance Department of Computer and Information Science University of Pennsylvania Philadelphia, PA 19104, USA e-mail: [email protected] c Jean Gallier Please, do not reproduce without permission of the author April 28, 2020 2 Contents Contents 3 1 RAM Programs, Turing Machines 7 1.1 Partial Functions and RAM Programs . 10 1.2 Definition of a Turing Machine . 15 1.3 Computations of Turing Machines . 17 1.4 Equivalence of RAM programs And Turing Machines . 20 1.5 Listable Languages and Computable Languages . 21 1.6 A Simple Function Not Known to be Computable . 22 1.7 The Primitive Recursive Functions . 25 1.8 Primitive Recursive Predicates . 33 1.9 The Partial Computable Functions . 35 2 Universal RAM Programs and the Halting Problem 41 2.1 Pairing Functions . 41 2.2 Equivalence of Alphabets . 48 2.3 Coding of RAM Programs; The Halting Problem . 50 2.4 Universal RAM Programs . 54 2.5 Indexing of RAM Programs . 59 2.6 Kleene's T -Predicate . 60 2.7 A Non-Computable Function; Busy Beavers . 62 3 Elementary Recursive Function Theory 67 3.1 Acceptable Indexings . 67 3.2 Undecidable Problems . 70 3.3 Reducibility and Rice's Theorem . 73 3.4 Listable (Recursively Enumerable) Sets . 76 3.5 Reducibility and Complete Sets . 82 4 The Lambda-Calculus 87 4.1 Syntax of the Lambda-Calculus . 89 4.2 β-Reduction and β-Conversion; the Church{Rosser Theorem . 94 4.3 Some Useful Combinators . -
What Is Computation? the Enduring Legacy of the Turing Machine by Lance Fortnow, Northwestern University
Ubiquity, an ACM publication December, 2010 Ubiquity Symposium What is Computation? The Enduring Legacy of the Turing Machine by Lance Fortnow, Northwestern University Editor’s Introduction In this eighth article in the ACM Ubiquity symposium discussing, What is Computation?, Lance Fortnow invokes the significance of the Turing machine in addressing the question. Editor http://ubiquity.acm.org 1 ©2010 Association for Computing Machinery Ubiquity, an ACM publication December, 2010 Ubiquity Symposium What is Computation? The Enduring Legacy of the Turing Machine by Lance Fortnow, Northwestern University Supported in part by NSF grants CCF‐0829754 and DMS‐0652521 This is one of a series of Ubiquity articles addressing the question “What is Computation?” Alan Turing1, in his seminal 1936 paper On computable numbers, with an application to the Entscheidungsproblem [4], directly answers this question by describing the now classic Turing machine model. The Church‐Turing thesis is simply stated. Everything computable is computable by a Turing machine. The Church‐Turing thesis has stood the test of time, capturing computation models Turing could not have conceived of, including digital computation, probabilistic, parallel and quantum computers and the Internet. The thesis has become accepted doctrine in computer science and the ACM has named its highest honor after Turing. Many now view computation as a fundamental part of nature, like atoms or the integers. So why are we having a series now asking a question that was settled in the 1930s? A few computer scientists nevertheless try to argue that the thesis fails to capture some aspects of computation. Some of these have been published in prestigious venues such as Science [2], the Communications of the ACM [5] and now as a whole series of papers in ACM Ubiquity. -
A Game Plan for Quantum Computing
February 2020 A game plan for quantum computing Thanks to technology advances, some companies may reap real gains from quantum computing within five years. What should you do to prepare for this next big wave in computers? by Alexandre Ménard, Ivan Ostojic, Mark Patel, and Daniel Volz Pharmaceutical companies have an abiding interest in enzymes. These proteins catalyze all kinds of biochemical interactions, often by targeting a single type of molecule with great precision. Harnessing the power of enzymes may help alleviate the major diseases of our time. Unfortunately, we don’t know the exact molecular structure of most enzymes. In principle, chemists could use computers to model these molecules in order to identify how the molecules work, but enzymes are such complex structures that most are impossible for classical computers to model. A sufficiently powerful quantum computer, however, could accurately predict in a matter of hours the properties, structure, and reactivity of such substances—an advance that could revolutionize drug development and usher in a new era in healthcare. Quantum computers have the potential to resolve problems of this complexity and magnitude across many different industries and applications, including finance, transportation, chemicals, and cybersecurity. Solving the impossible in a few hours of computing time, finding answers to problems that have bedeviled science and society for years, unlocking unprecedented capabilities for businesses of all kinds—those are the promises of quantum computing, a fundamentally different approach to computation. None of this will happen overnight. In fact, many companies and businesses won’t be able to reap significant value from quantum computing for a decade or more, although a few will see gains in the next five years. -
Models of Computation (RAM)
Models of Computation Analysis of Algorithms Week 1, Lecture 2 Prepared by John Reif, Ph.D. Distinguished Professor of Computer Science Duke University Models of Computation (RAM) a) Random Access Machines b) Straight Line Programs and Circuits c) Vector Machines d) Turing Machines e) Pointer Machines f) Decision Trees g) Machines That Make Random Choices Readings • Main Reading Selection: • CLR, Chapter 1 and 2 Random Access Machine (RAM) RAM Assumptions 1) Each register holds an integer 2) Program can’t modify itself 3) Memory instructions involve simple arithmetic a) Addition, subtraction b) Multiplication, division and control states (got, if-then, etc.) Simplified Program Style Complexity Measures of Algorithms Input X output size n=|X| => Algorithm A => • TimeA (X) = time cost of Algorithm A, input X • SpaceA (X) = space cost of Algorithm A, input X • Note: “time” and “space” depend on machine Complexity Measures of Algorithms (cont’d) • Worst case TAA (n) = max (Time (X)) time complexity {x:|x|=n} E(T (n))= Time (X)Prob(X) • Average case complexity AA∑ for random inputs {x:|x|=n} • Worst case S(n)AA = max (Space(X)) space complexity {x:|x|=n} • Average case complexity E(S (n))= Space (X)Prob(X) for random inputs AA∑ {x:|x|=n} Cost Criteria • Uniform Cost Criteria Time = # RAM instructions space = # RAM memory registers • Logarithmic Cost Criteria – Time= L(i) units per RAM instruction on integer size i – Space = L(i) units per RAM register on integer size i Cost Criteria (cont’d) log |i| i 0 ⎧ ⎣⎦≠ where L(i) = ⎨ ⎩ 1 i= 0 • Example Z2← for k=1 to n do Z←⋅ Z Z n ouput Z = 22 Uniform time cost = n Logarithmic time cost > 2n Varieties of Computing Machine Models RAMs Straight line programs Circuits Bit vectors Lisp machines … Turning Machines Straight Line Programs • Idea • fix n = input size • unroll each iteration loop until result is loop-free program Pn • For each n > 0, get a distinct program Pn Note: this is only possible if we can eliminate all branching and all indirect addressing Example • Given polynomial p(x) = a xnn-1 + a x + .. -
Foundations of Computation, Version 2.3.2 (Summer 2011)
Foundations of Computation Second Edition (Version 2.3.2, Summer 2011) Carol Critchlow and David Eck Department of Mathematics and Computer Science Hobart and William Smith Colleges Geneva, New York 14456 ii c 2011, Carol Critchlow and David Eck. Foundations of Computation is a textbook for a one semester introductory course in theoretical computer science. It includes topics from discrete mathematics, automata the- ory, formal language theory, and the theory of computation, along with practical applications to computer science. It has no prerequisites other than a general familiarity with com- puter programming. Version 2.3, Summer 2010, was a minor update from Version 2.2, which was published in Fall 2006. Version 2.3.1 is an even smaller update of Version 2.3. Ver- sion 2.3.2 is identical to Version 2.3.1 except for a change in the license under which the book is released. This book can be redistributed in unmodified form, or in mod- ified form with proper attribution and under the same license as the original, for non-commercial uses only, as specified by the Creative Commons Attribution-Noncommercial-ShareAlike 4.0 Li- cense. (See http://creativecommons.org/licenses/by-nc-sa/4.0/) This textbook is available for on-line use and for free download in PDF form at http://math.hws.edu/FoundationsOfComputation/ and it can be purchased in print form for the cost of reproduction plus shipping at http://www.lulu.com Contents Table of Contents iii 1 Logic and Proof 1 1.1 Propositional Logic ....................... 2 1.2 Boolean Algebra ....................... -
Introduction to Theory of Computation
Introduction to Theory of Computation Anil Maheshwari Michiel Smid School of Computer Science Carleton University Ottawa Canada anil,michiel @scs.carleton.ca { } April 17, 2019 ii Contents Contents Preface vi 1 Introduction 1 1.1 Purposeandmotivation ..................... 1 1.1.1 Complexitytheory .................... 2 1.1.2 Computability theory . 2 1.1.3 Automatatheory ..................... 3 1.1.4 Thiscourse ........................ 3 1.2 Mathematical preliminaries . 4 1.3 Prooftechniques ......................... 7 1.3.1 Directproofs ....................... 8 1.3.2 Constructiveproofs. 9 1.3.3 Nonconstructiveproofs . 10 1.3.4 Proofsbycontradiction. 11 1.3.5 The pigeon hole principle . 12 1.3.6 Proofsbyinduction. 13 1.3.7 Moreexamplesofproofs . 15 Exercises................................. 18 2 Finite Automata and Regular Languages 21 2.1 An example: Controling a toll gate . 21 2.2 Deterministic finite automata . 23 2.2.1 Afirstexampleofafiniteautomaton . 26 2.2.2 Asecondexampleofafiniteautomaton . 28 2.2.3 A third example of a finite automaton . 29 2.3 Regularoperations ........................ 31 2.4 Nondeterministic finite automata . 35 2.4.1 Afirstexample ...................... 35 iv Contents 2.4.2 Asecondexample..................... 37 2.4.3 Athirdexample...................... 38 2.4.4 Definition of nondeterministic finite automaton . 39 2.5 EquivalenceofDFAsandNFAs . 41 2.5.1 Anexample ........................ 44 2.6 Closureundertheregularoperations . 48 2.7 Regularexpressions. .. .. 52 2.8 Equivalence of regular expressions and regular languages . 56 2.8.1 Every regular expression describes a regular language . 57 2.8.2 Converting a DFA to a regular expression . 60 2.9 The pumping lemma and nonregular languages . 67 2.9.1 Applications of the pumping lemma . 69 2.10Higman’sTheorem ........................ 76 2.10.1 Dickson’sTheorem . -
What Is Computation? Peter J
A Ubiquity Symposium Opening Statement FINAL v5– 8/26/10 What is Computation? Peter J. Denning Peter J. Denning ([email protected]) is Director of the Cebrowski Institute for innovation and information superiority at the Naval Postgraduate School in Monterey, California, and is a past president of ACM. He is currently the editor in chief of Ubiquity. Abstract: Most people understand a computation as a process evoked when a computational model (or computational agent) acts on its inputs under the control of an algorithm to produce its results. The classical Turing machine model has long served as the fundamental reference model because an appropriate Turing machine can simulate every other computational model known. The Turing model is a good abstraction for most digital computers because the number of steps to execute a Turing machine algorithm is predictive of the running time of the computation on a digital computer. However, the Turing model is not as well matched for the natural, interactive, and continuous information processes frequently encountered today; other models more closely match the information processes involved and give better predictions of running time and space. The question before us -- what is computation? -- is at least as old as computer science. It is one of those questions that will never be fully settled because new discoveries and maturing understandings constantly lead to new insights. It is like the fundamental questions in other fields -- for example, “what is life?” in biology and “what are the fundamental forces?” in physics -- that will never be fully resolved. Engaging with the question is more valuable than finding a definitive answer.