Drawing Hands
''Drawing Hands'' is a lithograph by the Dutch artist M. C. Escher first printed in January 1948. It depicts a sheet of paper, out of which two hands rise, in the paradoxical act of drawing one another into existence. This is one of the most obvious examples of Escher's common use of paradox. It is referenced in the book ''Gödel, Escher, Bach'', by Douglas Hofstadter, who calls it an example of a strange loop. It is used in ''Structure and Interpretation of Computer Programs'' by Harold Abelson and Gerald Jay Sussman as an allegory for the eval and apply functions of programming language interpreters in computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ..., which feed each other. ''Drawing Hands'' has been referenced and copied many times by artists in different ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Image Scanner
An image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. Commonly used in offices are variations of the desktop ''flatbed scanner'' where the document is placed on a glass window for scanning. ''Hand-held scanners'', where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical. Modern scanners typically use a charge-coupled device (CCD) or a contact image sensor (CIS) as the image sensor, whereas ''drum scanners'', developed earlier and still used for the highest possible image quality, use a photomultiplier tube (PMT) as the image sensor. A ''rotary scanner,'' used for high-speed documen ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Structure And Interpretation Of Computer Programs
''Structure and Interpretation of Computer Programs'' (''SICP'') is a computer science textbook by Massachusetts Institute of Technology professors Harold Abelson and Gerald Jay Sussman with Julie Sussman. It is known as the "Wizard Book" in hacker culture. It teaches fundamental principles of computer programming, including recursion, abstraction, modularity, and programming language design and implementation. MIT Press published the first edition in 1984, and the second edition in 1996. It was formerly used as the textbook for MIT's introductory course in computer science. SICP focuses on discovering general patterns for solving specific problems, and building software systems that make use of those patterns. MIT Press published the JavaScript edition in 2022. Content The book describes computer science concepts using Scheme, a dialect of Lisp. It also uses a virtual register machine and assembler to implement Lisp interpreters and compilers. Characters Several fiction ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Harry N
Harry may refer to: TV shows * ''Harry'' (American TV series), a 1987 American comedy series starring Alan Arkin * ''Harry'' (British TV series), a 1993 BBC drama that ran for two seasons * ''Harry'' (talk show), a 2016 American daytime talk show hosted by Harry Connick Jr. People and fictional characters * Harry (given name), a list of people and fictional characters with the given name * Harry (surname), a list of people with the surname * Dirty Harry (musician) (born 1982), British rock singer who has also used the stage name Harry * Harry Potter (character), the main protagonist in a Harry Potter fictional series by J. K. Rowling Other uses * Harry (derogatory term), derogatory term used in Norway * ''Harry'' (album), a 1969 album by Harry Nilsson *The tunnel used in the Stalag Luft III escape ("The Great Escape") of World War II * ''Harry'' (newspaper), an underground newspaper in Baltimore, Maryland See also *Harrying (laying waste), may refer to the following historical ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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FreakingNews
FreakingNews was a news-oriented Photoshop contest website that came online August 2, 2002 and officially opened on October 23, 2003 as a sister site of Worth1000. This virtual community of 17,000+ digital artists and members features free daily Photoshop contests that are fueled by global news and events. Since its inception, FreakingNews has been featured on television shows, magazines and newspapers, including Comedy Central, MTV, Weekly World News, Glenn Beck Show, Stern Magazine, The Guardian, The Daily News, The Dallas Morning News, Los Angeles Times, The Daily Mail, and The Sun. The site closed in 2020. History Vladislav Golunov and Rich Taylor became online friends in 2001 when Golunov contacted Taylor after he had seen a photo-manipulated image that Taylor had created under the pseudonym Internet screenname "Registered". Golunov had an existing website that posted humorous images with the visitor being able to leave comments or share the images via email. Taylor ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Digital Illustration
Digital illustration or computer illustration is the use of digital tools to produce images under the direct manipulation of the artist, usually through a pointing device such as a tablet or a mouse. It is distinguished from computer-''generated'' art, which is produced by a computer using mathematical models created by the artist. It is also distinct from digital manipulation of photographs, in that it is an original construction "from scratch". Photographic elements such as background or texture may be incorporated into such works, but they are not necessarily the primary basis. Pointing devices Mice are not very precise for drawing, so a graphics tablet is an important tool for a digital illustrator, because it allows the user to make a mark easily in any direction, in a way that reflects the natural or "lively" line made by the human hand. In addition to flexibility of movement, an industry-standard digital drawing tablet has a pressure-sensitive surface, allowing the illustra ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Computer Science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical disciplines (including the design and implementation of Computer architecture, hardware and Computer programming, software). Computer science is generally considered an area of research, academic research and distinct from computer programming. Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and for preventing Vulnerability (computing), security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Progr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Apply
In mathematics and computer science, apply is a function that applies a function to arguments. It is central to programming languages derived from lambda calculus, such as LISP and Scheme, and also in functional languages. It has a role in the study of the denotational semantics of computer programs, because it is a continuous function on complete partial orders. Apply is also a continuous function in homotopy theory, and, indeed underpins the entire theory: it allows a homotopy deformation to be viewed as a continuous path in the space of functions. Likewise, valid mutations (refactorings) of computer programs can be seen as those that are "continuous" in the Scott topology. The most general setting for apply is in category theory, where it is right adjoint to currying in closed monoidal categories. A special case of this are the Cartesian closed categories, whose internal language is simply typed lambda calculus. Programming In computer programming, apply applies a function ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Eval
In some programming languages, eval , short for the English evaluate, is a function which evaluates a string as though it were an expression in the language, and returns a result; in others, it executes multiple lines of code as though they had been included instead of the line including the eval. The input to eval is not necessarily a string; it may be structured representation of code, such as an abstract syntax tree (like Lisp forms), or of special type such as code (as in Python). The analog for a statement is exec, which executes a string (or code in other format) as if it were a statement; in some languages, such as Python, both are present, while in other languages only one of either eval or exec is. Eval and apply are instances of meta-circular evaluators, interpreters of a language that can be invoked within the language itself. Security risks Using eval with data from an untrusted source may introduce security vulnerabilities. For instance, assuming that the get_da ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gerald Jay Sussman
Gerald Jay Sussman (born February 8, 1947) is the Panasonic Professor of Electrical Engineering at the Massachusetts Institute of Technology (MIT). He received his S.B. and Ph.D. degrees in mathematics from MIT in 1968 and 1973 respectively. He has been involved in artificial intelligence (AI) research at MIT since 1964. His research has centered on understanding the problem-solving strategies used by scientists and engineers, with the goals of automating parts of the process and formalizing it to provide more effective methods of science and engineering education. Sussman has also worked in computer languages, in computer architecture and in Very Large Scale Integration (VLSI) design. Education Sussman attended the Massachusetts Institute of Technology as an undergraduate and received his S.B. in mathematics in 1968. He continued his studies at MIT and obtained a Ph.D. in 1973, also in mathematics, under the supervision of Seymour Papert. His doctoral thesis was titled "A Co ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Harold Abelson
Harold Abelson (born April 26, 1947) is the Class of 1922 Professor of Computer Science and Engineering in the Department of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology (MIT), a fellow of the Institute of Electrical and Electronics Engineers (IEEE), and a founding director of both Creative Commons and the Free Software Foundation. He directed the first implementation of the language Logo for the Apple II, which made the language widely available on personal computers starting in 1981; and published a widely selling book on Logo in 1982. Together with Gerald Jay Sussman, Abelson developed MIT's introductory computer science subject, ''The Structure and Interpretation of Computer Programs'' (called by the course number, 6.001), a subject organized around the idea that a computer language is primarily a formal medium for expressing ideas about methodology, rather than just a way to get a computer to perform operations. Abelson and Sussman ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Strange Loop
A strange loop is a cyclic structure that goes through several levels in a hierarchical system. It arises when, by moving only upwards or downwards through the system, one finds oneself back where one started. Strange loops may involve self-reference and paradox. The concept of a strange loop was proposed and extensively discussed by Douglas Hofstadter in '' Gödel, Escher, Bach'', and is further elaborated in Hofstadter's book ''I Am a Strange Loop'', published in 2007. A tangled hierarchy is a hierarchical consciousness system in which a strange loop appears. Definitions A strange loop is a hierarchy of levels, each of which is linked to at least one other by some type of relationship. A strange loop hierarchy is "tangled" (Hofstadter refers to this as a "heterarchy"), in that there is no well defined highest or lowest level; moving through the levels, one eventually returns to the starting point, i.e., the original level. Examples of strange loops that Hofstadter offers ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lithograph
Lithography () is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by the German author and actor Alois Senefelder and was initially used mostly for musical scores and maps.Meggs, Philip B. A History of Graphic Design. (1998) John Wiley & Sons, Inc. p 146 Carter, Rob, Ben Day, Philip Meggs. Typographic Design: Form and Communication, Third Edition. (2002) John Wiley & Sons, Inc. p 11 Lithography can be used to print text or images onto paper or other suitable material. A lithograph is something printed by lithography, but this term is only used for fine art prints and some other, mostly older, types of printed matter, not for those made by modern commercial lithography. Originally, the image to be printed was drawn with a greasy substance, such as oil, fat, or wax onto the surface of a smooth and flat limestone plat ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |