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Greg Nelson (computer Scientist)
Charles Gregory Nelson (27 March 1953 – 2 February 2015) was an American computer scientist. Biography Nelson grew up in Honolulu. As a boy he excelled at gymnastics and tennis. He attended the University Laboratory School. He received his B.A. degree in mathematics from Harvard University in 1976. He received his Ph.D. in computer science from Stanford University in 1980 under the supervision of Robert Tarjan. He lived in Juneau, Alaska for a year before settling permanently in the San Francisco Bay Area. Notable work His thesis, ''Techniques for Program Verification'', influenced both program verification and automated theorem proving, especially in the area now named satisfiability modulo theories, where he contributed techniques for combining decision procedures, as well as efficient decision procedures for quantifier-free constraints in first-order logic and term algebra. He received the Herbrand Award in 2013: He was instrumental in developing the ''Simplify ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PARC (company)
PARC (Palo Alto Research Center; formerly Xerox PARC) is a research and development company in Palo Alto, California. Founded in 1969 by Jacob E. "Jack" Goldman, chief scientist of Xerox Corporation, the company was originally a division of Xerox, tasked with creating computer technology-related products and hardware systems. Xerox PARC has been at the heart of numerous revolutionary computer developments, including laser printing, Ethernet, the modern personal computer, GUI (graphical user interface) and desktop paradigm, object-oriented programming, ubiquitous computing, electronic paper, a-Si (amorphous silicon) applications, the computer mouse, and VLSI ( very-large-scale integration) for semiconductors. Unlike Xerox's existing research laboratory in Rochester, New York, which focused on refining and expanding the company's copier business, Goldman's “Advanced Scientific & Systems Laboratory” aimed to pioneer new technologies in advanced physics, materials science, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco Bay Area
The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Governments to include the nine counties that border the aforementioned estuaries: Alameda, Contra Costa, Marin, Napa, San Mateo, Santa Clara, Solano, Sonoma, and San Francisco. Other definitions may be either smaller or larger, and may include neighboring counties that do not border the bay such as Santa Cruz and San Benito (more often included in the Central Coast regions); or San Joaquin, Merced, and Stanislaus (more often included in the Central Valley). The core cities of the Bay Area are San Francisco, San Jose, and Oakland. Home to approximately 7.76 million people, Northern California's nine-county Bay Area contains many cities, towns, airports, and associated regional, state, and national parks, connected by a comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1953 Births
Events January * January 6 – The Asian Socialist Conference opens in Rangoon, Burma. * January 12 – Estonian émigrés found a government-in-exile in Oslo. * January 14 ** Marshal Josip Broz Tito is chosen President of Yugoslavia. ** The CIA-sponsored Robertson Panel first meets to discuss the UFO phenomenon. * January 15 – Georg Dertinger, foreign minister of East Germany, is arrested for spying. * January 19 – 71.1% of all television sets in the United States are tuned into ''I Love Lucy'', to watch Lucy give birth to Little Ricky, which is more people than those who tune into Dwight Eisenhower's inauguration the next day. This record has yet to be broken. * January 20 – Dwight D. Eisenhower is sworn in as the 34th President of the United States. * January 24 ** Mau Mau Uprising: Rebels in Kenya kill the Ruck family (father, mother, and six-year-old son). ** Leader of East Germany Walter Ulbricht announces that agriculture will be col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Programmers
This is a list of programmers notable for their contributions to software, either as original author or architect, or for later additions. All entries must already have associated articles. A *Michael Abrash – program optimization and x86 assembly language *Scott Adams – series of text adventures beginning in the late 1970s *Tarn Adams – Dwarf Fortress *Leonard Adleman – cocreated RSA algorithm (being the ''A'' in that name), coined the term ''computer virus'' *Alfred Aho – cocreated AWK (being the ''A'' in that name), and main author of famous Compilers: Principles, Techniques, and Tools (Dragon book) *Andrei Alexandrescu – author, expert on languages C++, D *Paul Allen – Altair BASIC, Applesoft BASIC, cofounded Microsoft *Eric Allman – sendmail, syslog * Marc Andreessen – cocreated Mosaic, cofounded Netscape *Jeremy Ashkenas – CoffeeScript programming language and Backbone.js *Bill Atkinson – QuickDraw, HyperCard B *Roland Carl Backhouse – com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Computer Scientists
This is a list of computer scientists, people who do work in computer science, in particular researchers and authors. Some persons notable as programmers are included here because they work in research as well as program. A few of these people pre-date the invention of the digital computer; they are now regarded as computer scientists because their work can be seen as leading to the invention of the computer. Others are mathematicians whose work falls within what would now be called theoretical computer science, such as complexity theory and algorithmic information theory. A * Atta ur Rehman Khan – Mobile Cloud Computing, Cybersecurity, IoT * Wil van der Aalst – business process management, process mining, Petri nets * Scott Aaronson – quantum computing and complexity theory * Rediet Abebe – algorithms, artificial intelligence * Hal Abelson – intersection of computing and teaching * Serge Abiteboul – database theory * Samson Abramsky – game semantics * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread (computing)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. The implementation of threads and processes differs between operating systems. In Modern Operating Systems, Tanenbaum shows that many distinct models of process organization are possible.TANENBAUM, Andrew S. Modern Operating Systems. 1992. Prentice-Hall International Editions, ISBN 0-13-595752-4. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. History Threads made an early appearance under the name of "tasks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Generation (compiler)
In computing, code generation is part of the process chain of a compiler and converts intermediate representation of source code into a form (e.g., machine code) that can be readily executed by the target system. Sophisticated compilers typically perform multiple passes over various intermediate forms. This multi-stage process is used because many algorithms for code optimization are easier to apply one at a time, or because the input to one optimization relies on the completed processing performed by another optimization. This organization also facilitates the creation of a single compiler that can target multiple architectures, as only the last of the code generation stages (the ''backend'') needs to change from target to target. (For more information on compiler design, see Compiler.) The input to the code generator typically consists of a parse tree or an abstract syntax tree. The tree is converted into a linear sequence of instructions, usually in an intermediate language s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windowing System
In computing, a windowing system (or window system) is software that manages separately different parts of display screens. It is a type of graphical user interface (GUI) which implements the WIMP (windows, icons, menus, pointer) paradigm for a user interface. Each currently running application is assigned a usually resizable and usually rectangular surface of the display to present its GUI to the user; these windows may overlap each other, as opposed to a tiling interface where they are not allowed to overlap. Usually a window decoration is drawn around each window. The programming of both the window decoration and of available widgets inside of the window, which are graphical elements for direct user interaction, such as sliders, buttons, etc., is eased and simplified through the use of widget toolkits. Technical details The main component of any windowing system is usually called the display server, although alternative denominations such as window server or composit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming language is usually split into the two components of syntax (form) and semantics (meaning), which are usually defined by a formal language. Some languages are defined by a specification document (for example, the C programming language is specified by an ISO Standard) while other languages (such as Perl) have a dominant implementation that is treated as a reference. Some languages have both, with the basic language defined by a standard and extensions taken from the dominant implementation being common. Programming language theory is the subfield of computer science that studies the design, implementation, analysis, characterization, and classification of programming languages. Definitions There are many considerations when defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Term Algebra
In universal algebra and mathematical logic, a term algebra is a freely generated algebraic structure over a given signature. For example, in a signature consisting of a single binary operation, the term algebra over a set ''X'' of variables is exactly the free magma generated by ''X''. Other synonyms for the notion include absolutely free algebra and anarchic algebra. From a category theory perspective, a term algebra is the initial object for the category of all ''X''-generated algebras of the same signature, and this object, unique up to isomorphism, is called an initial algebra; it generates by homomorphic projection all algebras in the category. A similar notion is that of a Herbrand universe in logic, usually used under this name in logic programming, which is (absolutely freely) defined starting from the set of constants and function symbols in a set of clauses. That is, the Herbrand universe consists of all ground terms: terms that have no variables in them. An atomic for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First-order Logic
First-order logic—also known as predicate logic, quantificational logic, and first-order predicate calculus—is a collection of formal systems used in mathematics, philosophy, linguistics, and computer science. First-order logic uses quantified variables over non-logical objects, and allows the use of sentences that contain variables, so that rather than propositions such as "Socrates is a man", one can have expressions in the form "there exists x such that x is Socrates and x is a man", where "there exists''"'' is a quantifier, while ''x'' is a variable. This distinguishes it from propositional logic, which does not use quantifiers or relations; in this sense, propositional logic is the foundation of first-order logic. A theory about a topic is usually a first-order logic together with a specified domain of discourse (over which the quantified variables range), finitely many functions from that domain to itself, finitely many predicates defined on that domain, and a set of ax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decision Procedure
In computability theory and computational complexity theory, a decision problem is a computational problem that can be posed as a yes–no question of the input values. An example of a decision problem is deciding by means of an algorithm whether a given natural number is prime. Another is the problem "given two numbers ''x'' and ''y'', does ''x'' evenly divide ''y''?". The answer is either 'yes' or 'no' depending upon the values of ''x'' and ''y''. A method for solving a decision problem, given in the form of an algorithm, is called a decision procedure for that problem. A decision procedure for the decision problem "given two numbers ''x'' and ''y'', does ''x'' evenly divide ''y''?" would give the steps for determining whether ''x'' evenly divides ''y''. One such algorithm is long division. If the remainder is zero the answer is 'yes', otherwise it is 'no'. A decision problem which can be solved by an algorithm is called ''decidable''. Decision problems typically appear in ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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