Edsger W. Dijkstra: a Commemoration
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Thomas Ströhlein's Endgame Tables: a 50Th Anniversary
Thomas Ströhlein's Endgame Tables: a 50th Anniversary Article Supplemental Material The Festschrift on the 40th Anniversary of the Munich Faculty of Informatics Haworth, G. (2020) Thomas Ströhlein's Endgame Tables: a 50th Anniversary. ICGA Journal, 42 (2-3). pp. 165-170. ISSN 1389-6911 doi: https://doi.org/10.3233/ICG-200151 Available at http://centaur.reading.ac.uk/90000/ It is advisable to refer to the publisher’s version if you intend to cite from the work. See Guidance on citing . Published version at: https://content.iospress.com/articles/icga-journal/icg200151 To link to this article DOI: http://dx.doi.org/10.3233/ICG-200151 Publisher: The International Computer Games Association All outputs in CentAUR are protected by Intellectual Property Rights law, including copyright law. Copyright and IPR is retained by the creators or other copyright holders. Terms and conditions for use of this material are defined in the End User Agreement . www.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading Reading’s research outputs online 40 Jahre Informatik in Munchen:¨ 1967 – 2007 Festschrift Herausgegeben von Friedrich L. Bauer unter Mitwirkung von Helmut Angstl, Uwe Baumgarten, Rudolf Bayer, Hedwig Berghofer, Arndt Bode, Wilfried Brauer, Stephan Braun, Manfred Broy, Roland Bulirsch, Hans-Joachim Bungartz, Herbert Ehler, Jurgen¨ Eickel, Ursula Eschbach, Anton Gerold, Rupert Gnatz, Ulrich Guntzer,¨ Hellmuth Haag, Winfried Hahn (†), Heinz-Gerd Hegering, Ursula Hill-Samelson, Peter Hubwieser, Eike Jessen, Fred Kroger,¨ Hans Kuß, Klaus Lagally, Hans Langmaack, Heinrich Mayer, Ernst Mayr, Gerhard Muller,¨ Heinrich Noth,¨ Manfred Paul, Ulrich Peters, Hartmut Petzold, Walter Proebster, Bernd Radig, Angelika Reiser, Werner Rub,¨ Gerd Sapper, Gunther Schmidt, Fred B. -
A Politico-Social History of Algolt (With a Chronology in the Form of a Log Book)
A Politico-Social History of Algolt (With a Chronology in the Form of a Log Book) R. w. BEMER Introduction This is an admittedly fragmentary chronicle of events in the develop ment of the algorithmic language ALGOL. Nevertheless, it seems perti nent, while we await the advent of a technical and conceptual history, to outline the matrix of forces which shaped that history in a political and social sense. Perhaps the author's role is only that of recorder of visible events, rather than the complex interplay of ideas which have made ALGOL the force it is in the computational world. It is true, as Professor Ershov stated in his review of a draft of the present work, that "the reading of this history, rich in curious details, nevertheless does not enable the beginner to understand why ALGOL, with a history that would seem more disappointing than triumphant, changed the face of current programming". I can only state that the time scale and my own lesser competence do not allow the tracing of conceptual development in requisite detail. Books are sure to follow in this area, particularly one by Knuth. A further defect in the present work is the relatively lesser availability of European input to the log, although I could claim better access than many in the U.S.A. This is regrettable in view of the relatively stronger support given to ALGOL in Europe. Perhaps this calmer acceptance had the effect of reducing the number of significant entries for a log such as this. Following a brief view of the pattern of events come the entries of the chronology, or log, numbered for reference in the text. -
The Advent of Recursion & Logic in Computer Science
The Advent of Recursion & Logic in Computer Science MSc Thesis (Afstudeerscriptie) written by Karel Van Oudheusden –alias Edgar G. Daylight (born October 21st, 1977 in Antwerpen, Belgium) under the supervision of Dr Gerard Alberts, and submitted to the Board of Examiners in partial fulfillment of the requirements for the degree of MSc in Logic at the Universiteit van Amsterdam. Date of the public defense: Members of the Thesis Committee: November 17, 2009 Dr Gerard Alberts Prof Dr Krzysztof Apt Prof Dr Dick de Jongh Prof Dr Benedikt Löwe Dr Elizabeth de Mol Dr Leen Torenvliet 1 “We are reaching the stage of development where each new gener- ation of participants is unaware both of their overall technological ancestry and the history of the development of their speciality, and have no past to build upon.” J.A.N. Lee in 1996 [73, p.54] “To many of our colleagues, history is only the study of an irrele- vant past, with no redeeming modern value –a subject without useful scholarship.” J.A.N. Lee [73, p.55] “[E]ven when we can't know the answers, it is important to see the questions. They too form part of our understanding. If you cannot answer them now, you can alert future historians to them.” M.S. Mahoney [76, p.832] “Only do what only you can do.” E.W. Dijkstra [103, p.9] 2 Abstract The history of computer science can be viewed from a number of disciplinary perspectives, ranging from electrical engineering to linguistics. As stressed by the historian Michael Mahoney, different `communities of computing' had their own views towards what could be accomplished with a programmable comput- ing machine. -
Software Tools: a Building Block Approach
SOFTWARE TOOLS: A BUILDING BLOCK APPROACH NBS Special Publication 500-14 U.S. DEPARTMENT OF COMMERCE National Bureau of Standards ] NATIONAL BUREAU OF STANDARDS The National Bureau of Standards^ was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to pro- mote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, the Institute for Computer Sciences and Technology, the Office for Information Programs, and the ! Office of Experimental Technology Incentives Program. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consist- ent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essen- tial services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of the Office of Measurement Services, and the following center and divisions: Applied Mathematics — Electricity — Mechanics — Heat — Optical Physics — Center for Radiation Research — Lab- oratory Astrophysics^ — Cryogenics^ — Electromagnetics^ — Time and Frequency*. THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research leading to improved methods of measure- ment, standards, and data on the properties of well-characterized materials needed by industry, commerce, educational insti- tutions, and Government; provides advisory and research services to other Government agencies; and develops, produces, and distributes standard reference materials. -
7. Control Flow First?
Copyright (C) R.A. van Engelen, FSU Department of Computer Science, 2000-2004 Ordering Program Execution: What is Done 7. Control Flow First? Overview Categories for specifying ordering in programming languages: Expressions 1. Sequencing: the execution of statements and evaluation of Evaluation order expressions is usually in the order in which they appear in a Assignments program text Structured and unstructured flow constructs 2. Selection (or alternation): a run-time condition determines the Goto's choice among two or more statements or expressions Sequencing 3. Iteration: a statement is repeated a number of times or until a Selection run-time condition is met Iteration and iterators 4. Procedural abstraction: subroutines encapsulate collections of Recursion statements and subroutine calls can be treated as single Nondeterminacy statements 5. Recursion: subroutines which call themselves directly or indirectly to solve a problem, where the problem is typically defined in terms of simpler versions of itself 6. Concurrency: two or more program fragments executed in parallel, either on separate processors or interleaved on a single processor Note: Study Chapter 6 of the textbook except Section 7. Nondeterminacy: the execution order among alternative 6.6.2. constructs is deliberately left unspecified, indicating that any alternative will lead to a correct result Expression Syntax Expression Evaluation Ordering: Precedence An expression consists of and Associativity An atomic object, e.g. number or variable The use of infix, prefix, and postfix notation leads to ambiguity An operator applied to a collection of operands (or as to what is an operand of what arguments) which are expressions Fortran example: a+b*c**d**e/f Common syntactic forms for operators: The choice among alternative evaluation orders depends on Function call notation, e.g. -
Structured Programming - Retrospect and Prospect Harlan D
University of Tennessee, Knoxville Trace: Tennessee Research and Creative Exchange The aH rlan D. Mills Collection Science Alliance 11-1986 Structured Programming - Retrospect and Prospect Harlan D. Mills Follow this and additional works at: http://trace.tennessee.edu/utk_harlan Part of the Software Engineering Commons Recommended Citation Mills, Harlan D., "Structured Programming - Retrospect and Prospect" (1986). The Harlan D. Mills Collection. http://trace.tennessee.edu/utk_harlan/20 This Article is brought to you for free and open access by the Science Alliance at Trace: Tennessee Research and Creative Exchange. It has been accepted for inclusion in The aH rlan D. Mills Collection by an authorized administrator of Trace: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. mJNDAMNTL9JNNEPTS IN SOFTWARE ENGINEERING Structured Programming. Retrospect and Prospect Harlan D. Mills, IBM Corp. Stnuctured program- 2 ' dsger W. Dijkstra's 1969 "Struc- mon wisdom that no sizable program Ste red .tured Programming" articlel could be error-free. After, many sizable ming haxs changed ho w precipitated a decade of intense programs have run a year or more with no programs are written focus on programming techniques that has errors detected. since its introduction fundamentally alteredhumanexpectations and achievements in software devel- Impact of structured programming. two decades ago. opment. These expectations and achievements are However, it still has a Before this decade of intense focus, pro- not universal because of the inertia of lot of potentialfor gramming was regarded as a private, industrial practices. But they are well- lot of fo puzzle-solving activity ofwriting computer enough established to herald fundamental more change. -
The Advent of Recursion in Programming, 1950S-1960S
The Advent of Recursion in Programming, 1950s-1960s Edgar G. Daylight?? Institute of Logic, Language, and Computation, University of Amsterdam, The Netherlands [email protected] Abstract. The term `recursive' has had different meanings during the past two centuries among various communities of scholars. Its historical epistemology has already been described by Soare (1996) with respect to the mathematicians, logicians, and recursive-function theorists. The computer practitioners, on the other hand, are discussed in this paper by focusing on the definition and implementation of the ALGOL60 program- ming language. Recursion entered ALGOL60 in two novel ways: (i) syn- tactically with what we now call BNF notation, and (ii) dynamically by means of the recursive procedure. As is shown, both (i) and (ii) were in- troduced by linguistically-inclined programmers who were not versed in logic and who, rather unconventionally, abstracted away from the down- to-earth practicalities of their computing machines. By the end of the 1960s, some computer practitioners had become aware of the theoreti- cal insignificance of the recursive procedure in terms of computability, though without relying on recursive-function theory. The presented re- sults help us to better understand the technological ancestry of modern- day computer science, in the hope that contemporary researchers can more easily build upon its past. Keywords: recursion, recursive procedure, computability, syntax, BNF, ALGOL, logic, recursive-function theory 1 Introduction In his paper, Computability and Recursion [41], Soare explained the origin of computability, the origin of recursion, and how both concepts were brought to- gether in the 1930s by G¨odel, Church, Kleene, Turing, and others. -
A Common Programming Language for the Depart Final Ment of Defenses-Background and Technical January -December 1975 1 Requirements «
Approved for public release; distribution unlimited I 1 PAPER P-1191 A COMMON PROGRAMMING LANGUAGE 1 FOR THE DEPARTMENT OF DEFENSE - - I BACKGROUND AND TECHNICAL REQUIREMENTS I I D. A. Fisher June 1976 I 1 I I I I INSTITUTE FOR DEFENSE ANALYSES I SCIENCE AND TECHNOLOGY DIVISION I I IDA Log No. HQ 76-18215 I Cop-)*- > . -JJ . of 155. cop I ess Approved for public release; distribution unlimited I I I I The work reported in this document was conducted under contract DAHC15 73 C 0200 for the Department of Defense. The publication I of this IDA Paper does not indicate endorsement by the Department of Defense, nor should the contents be construed as reflecting the official position of that agency. I I I I This document has been approved for public release, distribution is unlimited. I I 1 1 1 I I I Copyright IDA/Scanned June 2007 I 1 Approved for public release; distribution unlimited UNCLASSIFIED - ©; ; ; : ;" -; .©, . 1 SECURITY CLASSIFICATION OF THIS PAGE CWnen DM* Entered; READ INSTRUCTIONS REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM ). RECIPIENT©S CATALOG NUMBER 1 Paper P-J.191. 4. TITLE fend Subtitle.) 5. TYPE Of REPORT e PERIOD COVERED A Common Programming Language for the Depart Final ment of Defenses-Background and Technical January -December 1975 1 Requirements «. PERFORMING ORG. REPORT NUMBER P-1191 I. CONTRACT OR GRANT NUMBERflJ 1 DAHC15 73 C 0200 D.A, Fisher 10. PROGRAM ELEMENT. PROJECT TASK 1 INSTITUTE FOR DEFENSE ANALYSES AREA * WORK UNIT NUMBERS 400 Army-Navy Drive Task T-36 Arlington. Virginia 22202 11. -
Glossary of Technical and Scientific Terms (French / English
Glossary of Technical and Scientific Terms (French / English) Version 11 (Alphabetical sorting) Jean-Luc JOULIN October 12, 2015 Foreword Aim of this handbook This glossary is made to help for translation of technical words english-french. This document is not made to be exhaustive but aim to understand and remember the translation of some words used in various technical domains. Words are sorted alphabetically. This glossary is distributed under the licence Creative Common (BY NC ND) and can be freely redistributed. For further informations about the licence Creative Com- mon (BY NC ND), browse the site: http://creativecommons.org If you are interested by updates of this glossary, send me an email to be on my diffusion list : • [email protected] • [email protected] Warning Translations given in this glossary are for information only and their use is under the responsability of the reader. If you see a mistake in this document, thank in advance to report it to me so i can correct it in further versions of this document. Notes Sorting of words Words are sorted by alphabetical order and are associated to their main category. Difference of terms Some words are different between the "British" and the "American" english. This glossary show the most used terms and are generally coming from the "British" english Words coming from the "American" english are indicated with the suffix : US . Difference of spelling There are some difference of spelling in accordance to the country, companies, universities, ... Words finishing by -ise, -isation and -yse can also be written with -ize, Jean-Luc JOULIN1 Glossary of Technical and Scientific Terms -ization and -yze. -
Early Life: 1924–1945
An interview with FRITZ BAUER Conducted by Ulf Hashagen on 21 and 26 July, 2004, at the Technische Universität München. Interview conducted by the Society for Industrial and Applied Mathematics, as part of grant # DE-FG02-01ER25547 awarded by the US Department of Energy. Transcript and original tapes donated to the Computer History Museum by the Society for Industrial and Applied Mathematics © Computer History Museum Mountain View, California ABSTRACT: Professor Friedrich L. Bauer describes his career in physics, computing, and numerical analysis. Professor Bauer was born in Thaldorf, Germany near Kelheim. After his schooling in Thaldorf and Pfarrkirchen, he received his baccalaureate at the Albertinium, a boarding school in Munich. He then faced the draft into the German Army, serving first in the German labor service. After training in France and a deployment to the Eastern Front in Kursk, he was sent to officer's school. His reserve unit was captured in the Ruhr Valley in 1945 during the American advance. He returned to Pfarrkirchen in September 1945 and in spring of 1946 enrolled in mathematics and physics at the Ludwig-Maximilians-Universitäat, München. He studied mathematics with Oscar Perron and Heinrich Tietze and physics with Arnold Sommerfeld and Paul August Mann. He was offered a full assistantship with Fritz Bopp and finished his Ph.D. in 1951 writing on group representations in particle physics. He then joined a group in Munich led by a professor of mathematics Robert Sauer and the electrical engineer Hans Piloty, working with a colleague Klaus Samelson on the design of the PERM, a computer based in part on the Whirlwind concept. -
Lecture 10: Fault Tolerance Fault Tolerant Concurrent Computing
02/12/2014 Lecture 10: Fault Tolerance Fault Tolerant Concurrent Computing • The main principles of fault tolerant programming are: – Fault Detection - Knowing that a fault exists – Fault Recovery - having atomic instructions that can be rolled back in the event of a failure being detected. • System’s viewpoint it is quite possible that the fault is in the program that is attempting the recovery. • Attempting to recover from a non-existent fault can be as disastrous as a fault occurring. CA463 Lecture Notes (Martin Crane 2014) 26 1 02/12/2014 Fault Tolerant Concurrent Computing (cont’d) • Have seen replication used for tasks to allow a program to recover from a fault causing a task to abruptly terminate. • The same principle is also used at the system level to build fault tolerant systems. • Critical systems are replicated, and system action is based on a majority vote of the replicated sub systems. • This redundancy allows the system to successfully continue operating when several sub systems develop faults. CA463 Lecture Notes (Martin Crane 2014) 27 Types of Failures in Concurrent Systems • Initially dead processes ( benign fault ) – A subset of the processes never even start • Crash model ( benign fault ) – Process executes as per its local algorithm until a certain point where it stops indefinitely – Never restarts • Byzantine behaviour (malign fault ) – Algorithm may execute any possible local algorithm – May arbitrarily send/receive messages CA463 Lecture Notes (Martin Crane 2014) 28 2 02/12/2014 A Hierarchy of Failure Types • Dead process – This is a special case of crashed process – Case when the crashed process crashes before it starts executing • Crashed process – This is a special case of Byzantine process – Case when the Byzantine process crashes, and then keeps staying in that state for all future transitions CA463 Lecture Notes (Martin Crane 2014) 29 Types of Fault Tolerance Algorithms • Robust algorithms – Correct processes should continue behaving thus, despite failures. -
Actor-Based Concurrency by Srinivas Panchapakesan
Concurrency in Java and Actor- based concurrency using Scala By, Srinivas Panchapakesan Concurrency Concurrent computing is a form of computing in which programs are designed as collections of interacting computational processes that may be executed in parallel. Concurrent programs can be executed sequentially on a single processor by interleaving the execution steps of each computational process, or executed in parallel by assigning each computational process to one of a set of processors that may be close or distributed across a network. The main challenges in designing concurrent programs are ensuring the correct sequencing of the interactions or communications between different computational processes, and coordinating access to resources that are shared among processes. Advantages of Concurrency Almost every computer nowadays has several CPU's or several cores within one CPU. The ability to leverage theses multi-cores can be the key for a successful high-volume application. Increased application throughput - parallel execution of a concurrent program allows the number of tasks completed in certain time period to increase. High responsiveness for input/output-intensive applications mostly wait for input or output operations to complete. Concurrent programming allows the time that would be spent waiting to be used for another task. More appropriate program structure - some problems and problem domains are well-suited to representation as concurrent tasks or processes. Process vs Threads Process: A process runs independently and isolated of other processes. It cannot directly access shared data in other processes. The resources of the process are allocated to it via the operating system, e.g. memory and CPU time. Threads: Threads are so called lightweight processes which have their own call stack but an access shared data.