Nat (unit)

natnatsnatural unit of information
The natural unit of information (symbol: nat), sometimes also nit or nepit, is a unit of information or entropy, based on natural logarithms and powers of e, rather than the powers of 2 and base 2 logarithms, which define the bit. This unit is also known by its unit symbol, the nat. The nat is the coherent unit for information entropy. The International System of Units, by assigning the same units (joule per kelvin) both to heat capacity and to thermodynamic entropy implicitly treats information entropy as a quantity of dimension one, with 1 nat = 1. Physical systems of natural units that normalize Boltzmann's constant to 1 are effectively measuring thermodynamic entropy in nats.

Entropy (information theory)

entropyinformation entropyShannon entropy
Although the analogy between both functions is suggestive, the following question must be set: is the differential entropy a valid extension of the Shannon discrete entropy? Differential entropy lacks a number of properties that the Shannon discrete entropy has – it can even be negative – and thus corrections have been suggested, notably limiting density of discrete points. To answer this question, we must establish a connection between the two functions: We wish to obtain a generally finite measure as the bin size goes to zero. In the discrete case, the bin size is the (implicit) width of each of the n (finite or infinite) bins whose probabilities are denoted by p n .

Units of information

unit of informationdecletunit of digital information
Base b = e, the base of natural logarithms: the unit is called a nat, nit, or nepit (from Neperian), and is worth log 2 e (≈ 1.443) bits. 1 bit – answer to a yes/no question. 1 byte – a number from 0 to 255. 90 bytes: enough to store a typical line of text from a book. 512 bytes = ½ KiB: the typical sector of a hard disk. 1024 bytes = 1 KiB: the classical block size in UNIX filesystems. 2048 bytes = 2 KiB: a CD-ROM sector. 4096 bytes = 4 KiB: a memory page in x86 (since Intel 80386). 4 kB: about one page of text from a novel. 120 kB: the text of a typical pocket book. 1 MiB – a 1024×1024 pixel bitmap image with 256 colors (8 bpp color depth). 3 MB – a three-minute song (133 kbit/s). 650–900 MB

Information theory

information theoristinformationinformation-theoretic
Channel coding is concerned with finding such nearly optimal codes that can be used to transmit data over a noisy channel with a small coding error at a rate near the channel capacity. 1 − H b (p) bits per channel use, where H b is the binary entropy function to the base-2 logarithm: * A binary erasure channel (BEC) with erasure probability p is a binary input, ternary output channel. The possible channel outputs are 0, 1, and a third symbol 'e' called an erasure. The erasure represents complete loss of information about an input bit. The capacity of the BEC is 1 − p bits per channel use. Information theoretic concepts apply to cryptography and cryptanalysis.

Grammatical mood

The interrogative (or interrogatory) mood is used for asking questions. In English, questions are considered interrogative. Most other languages do not have a special mood for asking questions, but exceptions include Welsh, Nenets and Eskimo languages such as Greenlandic. Linguistics also differentiate moods into two parental categories that include deontic mood and epistemic mood. Deontic mood describes whether one could or should be able to do something. An example of deontic mood is: She should/may start. On the other hand, epistemic mood describes the chance or possibility of something happening. This would then change our example to: She may have started.

Cognitive science

cognitive scientistcognitive sciencescognitive
Although clearly both genetic and environmental input is needed for a child to develop normally, considerable debate remains about how genetic information might guide cognitive development. In the area of language acquisition, for example, some (such as Steven Pinker) have argued that specific information containing universal grammatical rules must be contained in the genes, whereas others (such as Jeffrey Elman and colleagues in Rethinking Innateness) have argued that Pinker's claims are biologically unrealistic. They argue that genes determine the architecture of a learning system, but that specific "facts" about how grammar works can only be learned as a result of experience.


dialecticsdialecticaldialectical method
Many of these logics appear in the special area of artificial intelligence and law, though the computer scientists' interest in formalizing dialectic originates in a desire to build decision support and computer-supported collaborative work systems. 1) The question to be determined (“It is asked whether...”). 2) A provisory answer to the question (“And it seems that...”). 3) The principal arguments in favor of the provisory answer. 4) An argument against the provisory answer, traditionally a single argument from authority ("On the contrary..."). 5) The determination of the question after weighing the evidence ("I answer that..."). 6) The replies to each of the initial objections.

Media (communication)

mediamediumcommunication media
The latest inclusion in the field is magnetic media (magnetic stripe) whose application is common in the fastest growing information technology field. Modern day IT media is commonly used in the banking sector and by the Income Tax Department for the purpose of providing the easiest and fastest possible services to consumers. In this magnetic strip, account information linking to all the data relating to a particular consumer is stored. The main features of these types of media are prepared unrecorded (blank form), and data is normally stored at a later stage as per the requirement of its user or consumer.


double-stranded DNAdsDNAsingle-stranded DNA
Both strands of double-stranded DNA store the same biological information. This information is replicated as and when the two strands separate. A large part of DNA (more than 98% for humans) is non-coding, meaning that these sections do not serve as patterns for protein sequences. The two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases (informally, bases). It is the sequence of these four nucleobases along the backbone that encodes genetic information. RNA strands are created using DNA strands as a template in a process called transcription.

Socratic dialogue

dialoguedialoguesSocratic literature
The outcome of the dialogue is that Socrates demonstrates that the other person's views are inconsistent. In this way Socrates tries to show the way to real wisdom. One of his most famous statements in that regard is "The unexamined life is not worth living." This philosophical questioning is known as the Socratic method. In some dialogues Plato's main character is not Socrates but someone from outside of Athens. In Xenophon's Hiero a certain Simonides plays this role when Socrates is not the protagonist. Generally, the works which are most often assigned to Plato's early years are all considered to be Socratic dialogues (written from 399 to 387).

Affirmation and negation

Complications sometimes arise in the case of responses to negative statements or questions; in some cases the response that confirms a negative statement is the negative particle (as in English: "You're not going out? No."), but in some languages this is reversed. Some languages have a distinct form to answer a negative question, such as French si and Swedish jo (these serve to contradict the negative statement suggested by the first speaker). Languages have a variety of grammatical rules for converting affirmative verb phrases or clauses into negative ones. In many languages, an affirmative is made negative by the addition of a particle, meaning "not".

Digital physics

pancomputationalismcomputation-based universecriticism of digital physics
According to Luciano Floridi, "informational structural realism" is a variant of structural realism that supports an ontological commitment to a world consisting of the totality of informational objects dynamically interacting with each other. Such informational objects are to be understood as constraining affordances. Pancomputationalists like Lloyd (2006), who models the universe as a quantum computer, can still maintain an analogue or hybrid ontology; and informational ontologists like Kenneth Sayre and Floridi embrace neither a digital ontology nor a pancomputationalist position.

Information system

information systemscomputer information systemssystems
Among the support, equipment are input and output devices, storage devices and communications devices. 2) Software: The term software refers to computer programs and the manuals (if any) that support them. Computer programs are machine-readable instructions that direct the circuitry within the hardware parts of the system to function in ways that produce useful information from data. Programs are generally stored on some input/output medium, often a disk or tape. 3) Data: Data are facts that are used by programs to produce useful information.

Information science

information sciencesinformationInformation Studies
Basically, an information society is the means of getting information from one place to another (Wark, 1997, p. 22). As technology has become more advanced over time so too has the way we have adapted in sharing this information with each other. Information society theory discusses the role of information and information technology in society, the question of which key concepts should be used for characterizing contemporary society, and how to define such concepts. It has become a specific branch of contemporary sociology.

Information technology

ITinformation technologiesIT services
Health information technology. Information and communications technology (ICT). Information management. Journal of Cases on Information Technology. Knowledge society. List of the largest information technology companies. Outline of information technology. Computer science. Gitta, Cosmas and South, David (2011). Southern Innovator Magazine Issue 1: Mobile Phones and Information Technology: United Nations Office for South-South Cooperation. ISSN 2222-9280. Gleick, James (2011).The Information: A History, a Theory, a Flood. New York: Pantheon Books. Shelly, Gary, Cashman, Thomas, Vermaat, Misty, and Walker, Tim. (1999). Discovering Computers 2000: Concepts for a Connected World.


Some languages do not distinguish interrogative and indefinite pro-forms. In Mandarin, "Shéi yǒu wèntí?" means either "Who has a question?" or "Does anyone have a question?", depending on context. A pronoun substitutes a noun or a noun phrase, with or without a determiner: it, this. (Compare also prop-word; this denotes a word like one in "the blue one".). A pro-adjective substitutes an adjective or a phrase that functions as an adjective: so as in "It is less so than we had expected.". A pro-adverb substitutes an adverb or a phrase that functions as an adverb: how or this way. A pro-verb substitutes a verb or a verb phrase: do.

Theaetetus (dialogue)

Socrates tells Theaetetus that he cannot make out what knowledge is, and is looking for a simple formula for it. Theaetetus says he really has no idea how to answer the question, and Socrates tells him that he is there to help. Socrates says he has modelled his career after his midwife mother. She delivered babies and for his part, Socrates can tell when a young man is in the throes of trying to give birth to a thought. Socrates considers his philosophical work as midwifery (Maieutics). This method, later also called Socratic method, consists in eliciting knowledge by a series of questions and answers.


The high-frequency wave sent by the tower is modulated with a signal containing visual or audio information. The receiver is then tuned so as to pick up the high-frequency wave and a demodulator is used to retrieve the signal containing the visual or audio information. The broadcast signal can be either analog (signal is varied continuously with respect to the information) or digital (information is encoded as a set of discrete values). The broadcast media industry is at a critical turning point in its development, with many countries moving from analog to digital broadcasts. This move is made possible by the production of cheaper, faster and more capable integrated circuits.

Information processing

processingprocessprocessing of information
Latent and manifest information is defined through the terms of equivocation (remaining uncertainty, what value the sender has chosen), dissipation (uncertainty of the sender what the receiver has received), and transformation (saved effort of questioning – equivocation minus dissipation) (Denning and Bell, 2012). Within the field of cognitive psychology, information processing is an approach to the goal of understanding human thinking in relation to how they process the same kind of information as computers (Shannon & Weaver, 1963). It arose in the 1940s and 1950s, after World War II (Sternberg & Sternberg, 2012).

Display device

displayvideo monitorbezel
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal, the display is called an electronic display. Common applications for electronic visual displays are televisions or computer monitors. In the history of display technology, a variety of display devices and technologies have been used. There are various designs for display devices, using various technologies. Several components are common to most display devices. These are the technologies used to create the various displays in use today.

Information security

securitymessage integrityINFOSEC
Information security must protect information throughout its lifespan, from the initial creation of the information on through to the final disposal of the information. The information must be protected while in motion and while at rest. During its lifetime, information may pass through many different information processing systems and through many different parts of information processing systems. There are many different ways the information and information systems can be threatened. To fully protect the information during its lifetime, each component of the information processing system must have its own protection mechanisms.

Shannon–Hartley theorem

Shannon limitAWGN channel capacitychannel capacity
In information theory, the Shannon–Hartley theorem tells the maximum rate at which information can be transmitted over a communications channel of a specified bandwidth in the presence of noise. It is an application of the noisy-channel coding theorem to the archetypal case of a continuous-time analog communications channel subject to Gaussian noise.

Records management

record keepingrecordkeepingrecords
Throughout the records life cycle, issues such as security, privacy, disaster recovery, emerging technologies, and mergers are addressed by the records and information management professional responsible for organizational programs. Records and information management professionals are instrumental in controlling and safeguarding the information assets of the entity. They understand how to manage the creation, access, distribution, storage, and disposition of records and information in an efficient and cost-effective manner using records and information management methodology, principles, and best practices in compliance with records and information laws and regulations.


abstractabstractionsabstract thinking
Conceptual abstractions may be formed by filtering the information content of a concept or an observable phenomenon, selecting only the aspects which are relevant for a particular subjectively valued purpose. For example, abstracting a leather soccer ball to the more general idea of a ball selects only the information on general ball attributes and behavior, excluding, but not eliminating, the other phenomenal and cognitive characteristics of that particular ball. In a type–token distinction, a type (e.g., a 'ball') is more abstract than its tokens (e.g., 'that leather soccer ball'). Abstraction in its secondary use is a material process, discussed in the themes below.

Data storage

data storage devicestoragestorage media
A recording medium is a physical material that holds information. Newly created information is distributed and can be stored in four storage media–print, film, magnetic, and optical–and seen or heard in four information flows–telephone, radio and TV, and the Internet as well as being observed directly. Digital information is stored on electronic media in many different recording formats. With electronic media, the data and the recording media are sometimes referred to as "software" despite the more common use of the word to describe computer software.