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Superimposed Code
A superimposed code such as Zatocoding is a kind of hash code that was popular in marginal punched-card systems. Marginal punched-card systems Many names, some of them trademarked, have been used for marginal punched-card systems: edge-notched cards, slotted cards, E-Z Sort, Zatocards, McBee, McBee Keysort, Flexisort, Velom, Rocket, etc. The center of each card held the relevant information—typically the name and author of a book, research paper, or journal article on a nearby shelf; and a list of subjects and keywords. Some sets of cards contained all the information required by the user on the card itself, handwritten, typewritten, or on microfilm (aperture card). Every card in a stack had the same set of pre-punched holes. The user would find the particular cards relevant to a search by aligning the holes in the set of cards (using a card holder or card tray), inserting one or more knitting-needle-like rods all the way through the stack, so the desired cards (which had b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edge-notched Card
Edge-notched cards or edge-punched cards are a system used to store a small amount of binary or logical data on paper index cards, encoded via the presence or absence of notches in the edges of the cards. The notches allowed efficient sorting and selecting of specific cards matching multiple desired criteria, from a larger number of cards in a paper-based database of information. In the mid-20th century they were sold under names such as Cope-Chat cards, E-Z Sort cards, McBee Keysort, and Indecks cards. Overview Edge-notched cards are a manual data storage and manipulation technology used for specialized data storage and cataloging applications through much of the 20th century. An early instance of something like this methodology appeared in 1904. While there were many variants, by the mid-20th century a popular version consisted of paperboard cards with holes punched at regular intervals along all four edges, a short distance in from the edges. The center of the card might be b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Code
A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually used to index a fixed-size table called a ''hash table''. Use of a hash function to index a hash table is called ''hashing'' or ''scatter storage addressing''. Hash functions and their associated hash tables are used in data storage and retrieval applications to access data in a small and nearly constant time per retrieval. They require an amount of storage space only fractionally greater than the total space required for the data or records themselves. Hashing is a computationally and storage space-efficient form of data access that avoids the non-constant access time of ordered and unordered lists and structured trees, and the often exponential storage requirements of direct access of state spaces of large or variable-length keys. Use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edge-notched Card
Edge-notched cards or edge-punched cards are a system used to store a small amount of binary or logical data on paper index cards, encoded via the presence or absence of notches in the edges of the cards. The notches allowed efficient sorting and selecting of specific cards matching multiple desired criteria, from a larger number of cards in a paper-based database of information. In the mid-20th century they were sold under names such as Cope-Chat cards, E-Z Sort cards, McBee Keysort, and Indecks cards. Overview Edge-notched cards are a manual data storage and manipulation technology used for specialized data storage and cataloging applications through much of the 20th century. An early instance of something like this methodology appeared in 1904. While there were many variants, by the mid-20th century a popular version consisted of paperboard cards with holes punched at regular intervals along all four edges, a short distance in from the edges. The center of the card might be b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aperture Card
An aperture card is a type of punched card with a cut-out window into which a chip of microfilm is mounted. Such a card is used for archiving or for making multiple inexpensive copies of a document for ease of distribution. The card is typically punched with machine-readable metadata associated with the microfilm image, and printed across the top of the card for visual identification; it may also be punched by hand in the form of an edge-notched card. The microfilm chip is most commonly 35mm in height, and contains an optically reduced image, usually of some type of reference document, such as an engineering drawing, that is the focus of the archiving process. Machinery exists to automatically store, retrieve, sort, duplicate, create, and digitize cards with a high level of automation. Aperture cards have several advantages and disadvantages when compared to digital systems. While many aperture cards still play an important role in archiving, their role is gradually being re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean Searching
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variables are the truth values ''true'' and ''false'', usually denoted 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra uses logical operators such as conjunction (''and'') denoted as ∧, disjunction (''or'') denoted as ∨, and the negation (''not'') denoted as ¬. Elementary algebra, on the other hand, uses arithmetic operators such as addition, multiplication, subtraction and division. So Boolean algebra is a formal way of describing logical operations, in the same way that elementary algebra describes numerical operations. Boolean algebra was introduced by George Boole in his first book ''The Mathematical Analysis of Logic'' (1847), and set forth more fully in his '' An Investigation of the Laws of Thought'' (1854). According to Huntington, the term "Boolean algebra" wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvin Mooers
Calvin Northrup Mooers (October 24, 1919 – December 1, 1994), was an American computer scientist known for his work in information retrieval and for the programming language TRAC. Early life Mooers was a native of Minneapolis, Minnesota, attended the University of Minnesota, and received a bachelor's degree in mathematics in 1941. He worked at the Naval Ordnance Laboratory from 1941 to 1946, and then attended the Massachusetts Institute of Technology, where he earned a master's degree in mathematics and physics. At M.I.T. he developed a mechanical system using superimposed codes of descriptors for information retrieval called Zatocoding. He founded the Zator Company in 1947 to market this idea, and pursued work in information theory, information retrieval, and artificial intelligence. He coined the term "information retrieval", using it first in a conference paper presented in March 1950. See also a short paper published later that year from Mooers. Mooers's law He coine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zator Company
Calvin Northrup Mooers (October 24, 1919 – December 1, 1994), was an American computer scientist known for his work in information retrieval and for the programming language TRAC. Early life Mooers was a native of Minneapolis, Minnesota, attended the University of Minnesota, and received a bachelor's degree in mathematics in 1941. He worked at the Naval Ordnance Laboratory from 1941 to 1946, and then attended the Massachusetts Institute of Technology, where he earned a master's degree in mathematics and physics. At M.I.T. he developed a mechanical system using superimposed codes of descriptors for information retrieval called Zatocoding. He founded the Zator Company in 1947 to market this idea, and pursued work in information theory, information retrieval, and artificial intelligence. He coined the term "information retrieval", using it first in a conference paper presented in March 1950. See also a short paper published later that year from Mooers. Mooers's law He coined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugene Garfield
Eugene Eli Garfield (September 16, 1925 – February 26, 2017) was an American linguist and businessman, one of the founders of bibliometrics and scientometrics. He helped to create ''Current Contents'', ''Science Citation Index'' (SCI), ''Journal Citation Reports'', and ''Index Chemicus'', among others, and founded the magazine '' The Scientist''. Early life and education Garfield was born in 1925 in New York City as Eugene Eli Garfinkle, his mother being of Lithuanian Jewish ancestry. His parents were second generation immigrants living in East Bronx in New York City. He studied at the University of Colorado and University of California, Berkeley before getting a Bachelor of Science degree in chemistry from Columbia University in 1949. Garfield also received a degree in Library Science from Columbia University in 1953 He went on to do his PhD in the Department of Linguistics at the University of Pennsylvania, which he completed in 1961 for developing an algorithm for translatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbert Marvin Ohlman
Herbert Marvin Ohlman (1927–2002) is the inventor of permutation indexing, or Permuterm and is one of the pioneers of Information Science and Technology. He has been recognized and included in thPioneers of Information Science in North America Projectby ASIS. Permuterm is known as one of the first successful punch card indexing systems, and is still referenced today in the data indexing field. Ohlman published a variety of papers on Permuterm and other Information Science and Technology and communication topics, which are now at the Charles Babbage Institute at The University of Minnesota. Permuterm Ohlman first started work on information indexing in 1957 (working for SDC) when he noticed the peek-a-boo (coordinate) indexing system that searched for documents at the Lincoln Laboratory wasted space on most of the cards. Ohlman developed a system using IBM punch cards and tabulating machines that used one punch card for every document title, with significant title words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edge-notched Card
Edge-notched cards or edge-punched cards are a system used to store a small amount of binary or logical data on paper index cards, encoded via the presence or absence of notches in the edges of the cards. The notches allowed efficient sorting and selecting of specific cards matching multiple desired criteria, from a larger number of cards in a paper-based database of information. In the mid-20th century they were sold under names such as Cope-Chat cards, E-Z Sort cards, McBee Keysort, and Indecks cards. Overview Edge-notched cards are a manual data storage and manipulation technology used for specialized data storage and cataloging applications through much of the 20th century. An early instance of something like this methodology appeared in 1904. While there were many variants, by the mid-20th century a popular version consisted of paperboard cards with holes punched at regular intervals along all four edges, a short distance in from the edges. The center of the card might be b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloom Filter
A Bloom filter is a space-efficient probabilistic data structure, conceived by Burton Howard Bloom in 1970, that is used to test whether an element is a member of a set. False positive matches are possible, but false negatives are not – in other words, a query returns either "possibly in set" or "definitely not in set". Elements can be added to the set, but not removed (though this can be addressed with the counting Bloom filter variant); the more items added, the larger the probability of false positives. Bloom proposed the technique for applications where the amount of source data would require an impractically large amount of memory if "conventional" error-free hashing techniques were applied. He gave the example of a hyphenation algorithm for a dictionary of 500,000 words, out of which 90% follow simple hyphenation rules, but the remaining 10% require expensive disk accesses to retrieve specific hyphenation patterns. With sufficient core memory, an error-free hash co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
