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Samson Abramsky
Samson Abramsky (born 12 March 1953) is a British computer scientist who is a Professor of Computer Science at University College London. He was previously the Christopher Strachey Professor of Computing at Wolfson College, Oxford, from 2000 to 2021. Abramsky's early work included contributions to domain theory and the connections thereof with geometric logic. Since then, his work has covered the lazy lambda calculus, strictness analysis, concurrency theory, interaction categories and geometry of interaction, game semantics and quantum computing. Notably, he co-pioneered categorical quantum mechanics. More recently, he has been applying methods from categorical semantics to finite model theory, with applications to descriptive complexity. Education Abramsky was educated at Hasmonean Grammar School for Boys, Hendon and at King's College, Cambridge (BA 1975, MA Philosophy 1979, Diploma in Computer Science) and Queen Mary, University of London (PhD Computer Science 1988, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Computer Science
Theoretical computer science is a subfield of computer science and mathematics that focuses on the Abstraction, abstract and mathematical foundations of computation. It is difficult to circumscribe the theoretical areas precisely. The Association for Computing Machinery, ACM's Special Interest Group on Algorithms and Computation Theory (SIGACT) provides the following description: History While logical inference and mathematical proof had existed previously, in 1931 Kurt Gödel proved with his incompleteness theorem that there are fundamental limitations on what statements could be proved or disproved. Information theory was added to the field with A Mathematical Theory of Communication, a 1948 mathematical theory of communication by Claude Shannon. In the same decade, Donald Hebb introduced a mathematical model of Hebbian learning, learning in the brain. With mounting biological data supporting this hypothesis with some modification, the fields of neural networks and para ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lovelace Medal
The Lovelace Medal was established by BCS, The Chartered Institute for IT in 1998, and is presented to individuals who have made outstanding contributions to the understanding or advancement of computing. It is the top award in computing in the UK. Awardees deliver the Lovelace Lecture. The award is named after Countess Ada Lovelace, an English mathematician, scientist, and writer. Lovelace was the daughter of Lord Byron. She worked with computer pioneer Charles Babbage on the proposed mechanical general-purpose computer – the Analytical Engine, in 1842 and is often described as the world's first computer programmer. The medal is intended to be presented to individuals, without regard to their countries of domicile, provided a direct connection to the UK. It is generally anticipated that there will be one medalist each year, but the regulation does not preclude either several medalists or no medalist. Medal recipients Awardees include: *2024 Sue Sentance – for her excepti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Categorical Quantum Mechanics
Categorical quantum mechanics is the study of quantum foundations and quantum information using paradigms from mathematics and computer science, notably monoidal category theory. The primitive objects of study are physical processes, and the different ways these can be composed. It was pioneered in 2004 by Samson Abramsky and Bob Coecke. Categorical quantum mechanics is entry 18M40 in MSC2020. Mathematical setup Mathematically, the basic setup is captured by a dagger symmetric monoidal category: composition of morphisms models sequential composition of processes, and the tensor product describes parallel composition of processes. The role of the dagger is to assign to each state a corresponding test. These can then be adorned with more structure to study various aspects. For instance: * A dagger compact category allows one to distinguish between an "input" and "output" of a process. In the diagrammatic calculus, it allows wires to be bent, allowing for a less restricted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Computing
A quantum computer is a computer that exploits quantum mechanical phenomena. On small scales, physical matter exhibits properties of wave-particle duality, both particles and waves, and quantum computing takes advantage of this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices, and a scalable quantum computer could perform some calculations Exponential growth, exponentially faster than any modern "classical" computer. Theoretically a large-scale quantum computer could post-quantum cryptography, break some widely used encryption schemes and aid physicists in performing quantum simulator, physical simulations; however, the current state of the art is largely experimental and impractical, with several obstacles to useful applications. The basic unit of information in quantum computing, the qubit (or "quantum bit"), serves the same function as the bit in classical computing. However, unlike a classical bit, which can be in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Game Semantics
Game semantics is an approach to Formal semantics (logic), formal semantics that grounds the concepts of truth or Validity (logic), validity on Game theory, game-theoretic concepts, such as the existence of a winning strategy for a player. In this framework, logical formulas are interpreted as defining games between two players. The term encompasses several related but distinct traditions, including dialogical logic (developed by Paul Lorenzen and Kuno Lorenz in Germany starting in the 1950s) and game-theoretical semantics (developed by Jaakko Hintikka in Finland). Game semantics represents a significant departure from traditional Model theory, model-theoretic approaches by emphasizing the dynamic, interactive nature of logical reasoning rather than static truth assignments. It provides intuitive interpretations for various logical systems, including classical logic, intuitionistic logic, linear logic, and modal logic. The approach bears conceptual resemblances to ancient Socratic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometry Of Interaction
In proof theory, the Geometry of Interaction (GoI) was introduced by Jean-Yves Girard shortly after his work on linear logic. In linear logic, proofs can be seen as various kinds of networks as opposed to the flat tree structures of sequent calculus. To distinguish the real proof nets from all the possible networks, Girard devised a criterion involving trips in the network. Trips can in fact be seen as some kind of operator acting on the proof. Drawing from this observation, Girard described directly this operator from the proof and has given a formula, the so-called ''execution formula'', encoding the process of cut elimination at the level of operators. Subsequent constructions by Girard proposed variants in which proofs are represented as flows, or operators in von Neumann algebras. Those models were later generalised by Seiller's Interaction Graphs models. One of the first significant applications of GoI was a better analysis of Lamping's algorithm for optimal reduction for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrency Theory
Concurrency refers to the ability of a system to execute multiple tasks through simultaneous execution or time-sharing (context switching), sharing resources and managing interactions. Concurrency improves responsiveness, throughput, and scalability in modern computing, including: * Operating systems and embedded systems * Distributed systems, parallel computing, and high-performance computing * Database systems, web applications, and cloud computing Related concepts Concurrency is a broader concept that encompasses several related ideas, including: * Parallelism (simultaneous execution on multiple processing units). Parallelism executes tasks independently on multiple CPU cores. Concurrency allows for multiple ''threads of control'' at the program level, which can use parallelism or time-slicing to perform these tasks. Programs may exhibit parallelism only, concurrency only, both parallelism and concurrency, neither. * Multi-threading and multi-processing (shared system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strictness Analysis
In computer science, strictness analysis refers to any algorithm used to prove that a function in a non-strict functional programming language is strict in one or more of its arguments. This information is useful to compilers because strict functions can be compiled more efficiently. Thus, if a function is proven to be strict (using strictness analysis) at compile time, it can be compiled to use a more efficient calling convention without changing the meaning of the enclosing program. Note that a function f is said to ''diverge'' if it returns \: operationally, that would mean that f either causes abnormal termination of the enclosing program (e.g., failure with an error message) or that it loops infinitely. The notion of "divergence" is significant because a strict function is one that always diverges when given an argument that diverges, whereas a lazy (or non-strict) function is one that may or may not diverge when given such an argument. Strictness analysis attempts to determine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambda Calculus
In mathematical logic, the lambda calculus (also written as ''λ''-calculus) is a formal system for expressing computability, computation based on function Abstraction (computer science), abstraction and function application, application using variable Name binding, binding and Substitution (algebra), substitution. Untyped lambda calculus, the topic of this article, is a universal machine, a model of computation that can be used to simulate any Turing machine (and vice versa). It was introduced by the mathematician Alonzo Church in the 1930s as part of his research into the foundations of mathematics. In 1936, Church found a formulation which was #History, logically consistent, and documented it in 1940. Lambda calculus consists of constructing #Lambda terms, lambda terms and performing #Reduction, reduction operations on them. A term is defined as any valid lambda calculus expression. In the simplest form of lambda calculus, terms are built using only the following rules: # x: A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometric Logic
In mathematical logic, geometric logic is an infinitary generalisation of coherent logic, a restriction of first-order logic due to Skolem that is proof-theoretically tractable. Geometric logic is capable of expressing many mathematical theories and has close connections to topos theory. Definitions A theory of first-order logic is geometric if it can be axiomatised using only axioms of the form \bigwedge_ \phi_ \vee \dots \vee \phi_ \implies \bigvee_ \phi_ \vee \dots \vee \phi_ where I and J are disjoint collections of formulae indices that each may be infinite and the formulae φ are either atoms or negations of atoms. If all the axioms are finite (i.e., for each axiom, both I and J are finite), the theory is coherent. Theorem Every first-order theory has a coherent conservative extension. Significance list eight consequences of the above theorem that explain its significance (omitting footnotes and most references): #In the context of a sequent calculus such as G3c, speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domain Theory
Domain theory is a branch of mathematics that studies special kinds of partially ordered sets (posets) commonly called domains. Consequently, domain theory can be considered as a branch of order theory. The field has major applications in computer science, where it is used to specify denotational semantics, especially for functional programming languages. Domain theory formalizes the intuitive ideas of approximation and convergence in a very general way and is closely related to topology. Motivation and intuition The primary motivation for the study of domains, which was initiated by Dana Scott in the late 1960s, was the search for a denotational semantics of the lambda calculus. In this formalism, one considers "functions" specified by certain terms in the language. In a purely syntactic way, one can go from simple functions to functions that take other functions as their input arguments. Using again just the syntactic transformations available in this formalism, one can obtai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfson College, Oxford
Wolfson College () is a Colleges of the University of Oxford, constituent college of the University of Oxford in England. Wolfson is an all-graduate college, it prides itself on being one of the most international colleges at Oxford, with particular strengths in areas like global health, environmental studies, economics, and humanities. With a spacious, green campus located along the River Cherwell, it is known for its relaxed atmosphere, modern architecture and beautiful gardens, creating a peaceful environment for a focused academic community. Its motto is "Humani nil alienum," which translates as "Nothing human is alien to me." The historian and philosopher Isaiah Berlin, Sir Isaiah Berlin was the college's first president, and was instrumental not only in its founding, but establishing a tradition of academic excellence and egalitarianism. Since then, the college caters to a wide range of subjects, from the humanities to the social and natural sciences, being coeducational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
