omniomni/omni-engineering huggingface dataset:
Scan. Scan, SCAN or Scanning may refer to:

Science and technology

Computing and electronics
 Graham scan, an algorithm for finding the convex hull of a set of points in the plane
 3D scanning, of a real-world object or environment to collect three dimensional data
 Counter-scanning, in physical micro and nanotopography measuring instruments like scanning probe microscope
 Elevator algorithm or SCAN, a disk scheduling algorithm
 Image scanning, an optical scan of images, printed text, handwriting or an object
 Optical character recognition, optical recognition of printed text or printed sheet music
 Port scanner, in computer networking
 Prefix sum, an operation on lists that is also known as the scan operator
 Raster scan, the rectangular pattern of image capture and reconstruction in television
 Scan chain, a type of manufacturing test used with integrated circuits
 Scan line, one line in a raster scanning pattern
 Screen reading, on computers to quickly locate text elements and images
 Shared Check Authorization Network (SCAN), a database of bad check writers and collection agency for bad checks
 Space Communications and Navigation Program (SCaN), by NASA

Medical
 Schedules for Clinical Assessment in Neuropsychiatry (SCAN), a set of psychiatric diagnostic tools by WHO
 DMSA scan, a radionuclide scan used in kidney studies
 Medical imaging, of the interior of a body
 Medical ultrasound, the medical procedure for examining internal structures, especially when applied to developing foetuses in the womb
 CT scan (computed tomography scan)
 Magnetic resonance imaging, MRI scan
 Switch access scanning, a technique that allows users with motor impairments to use a computer using switch access
 Partner-assisted scanning, a technique that allows a person with severe disabilities to communicate

Businesses
 Scan Furniture, a former US chain in Washington, D.C., US 
 SCAN Health Plan, not-for-profit health care company based in Long Beach, California, US
 Scan AB or Scan Foods UK Ltd, the Swedish and UK subsidiaries of the Finnish HKScan
 Seattle Community Access Network, a former TV channel in Seattle, Washington, US 
 Scan (company), a software company based in Provo, Utah, US

Publishing
 Social Cognitive and Affective Neuroscience, a scientific journal
 Scanning (journal), a scanning microscopy scientific journal published by Hindawi
 Scan: Journal of Media Arts Culture, former online journal published by Macquarie University, Sydney, Australia
 SCAN (newspaper), the student newspaper at Lancaster University, UK

Other uses
 Scansion, in poetry
 Scan reading, a method of speed reading
 Scientific content analysis (SCAN), a disputed technique
 "Scan" (Prison Break episode), an episode of the television series Prison Break

See also

 Scanner (disambiguation)
 Skan (disambiguation)
 Scansion, the analysis of writing and verse regarding rhythmic and especially metrical structure
Security kernel. In telecommunications, the term security kernel has the following meanings: 

In computer and communications security, the central part of a computer or communications system hardware, firmware, and software that implements the basic security procedures for controlling access to system resources. 
A self-contained usually small collection of key security-related statements that (a) works as a part of an operating system to prevent unauthorized access to, or use of, the system and (b) contains criteria that must be met before specified programs can be accessed. 
Hardware, firmware, and software elements of a trusted computing base that implement the reference monitor concept.

References

National Information Systems Security Glossary

Computing terminology
Simplex signaling. Simplex signaling (SX) is signaling in which two conductors are used for a single telecommunication circuit, and a center-tapped coil, or its equivalent, is used to split the signaling current equally between the two conductors. The return path for the current is through ground. 

It is distinct from a phantom circuit in which the return current path for power or signaling is provided through different signal conductors.
SX signaling may be one-way, for intra-central-office use, or the simplex legs may be connected to form full-duplex signaling circuits that function like composite (CX) signaling circuits with E&M lead control.

Simplex is also used to describe a powering method where one or more signal conductors carries direct current to power a remote device, which sends its output signal back on the same conductor.  Phantom powering as used in audio is a form of simplex powering, as the return current flows through the ground or shield conductor.

References

Telephony signals
Single-frequency signaling. In telephony, single-frequency signaling (SF or SF tone) is line signaling in which dial pulses or supervisory signals are conveyed by a single-frequency tone in each direction in the voice-band.  SF and similar systems were used in 20th-century carrier systems.

An SF signaling unit converts DC signaling (usually, at least in long-distance circuits, E&M signaling) to a format (characterized by the presence or absence of a single voice-frequency tone), which is suitable for transmission over an AC path, e.g., a carrier system. The SF tone is present in the on-hook or idle state and absent during the seized state. In the seized state, dial pulses are conveyed by bursts of SF tone, corresponding to the interruptions in dc continuity created by a rotary dial or other DC dialing mechanism. 

The SF tone may occupy a small portion of the user data channel spectrum, e.g., 1600 Hz or 2600 Hz (SF "in-band signaling)". There may be a notch filter at the precise SF frequency, either filtering the circuit at all times or only when the circuit is off-hook, to prevent the user from inadvertently disconnecting a call if the users voice has a sufficiently strong spectral content at the SF frequency, a falsing condition known as talk-off. Notoriously, this property was exploited by blue boxers and other toll fraudsters. The SF tone may also be just outside the user voice band, e.g., 3600 Hz.  

The Defense Data Network (DDN) transmitted DC line signaling pulses or supervisory signals, or both, over carrier channels or cable pairs on a four-wire circuit basis using a 2600 Hz signal tone. The conversion into tones, or vice versa, is done by SF signal units.

SF was developed in the early 20th century and standardized in middle century.  It declined in the 1970s due to the adoption of T-carrier, and was largely abandoned late in the century in favor of common-channel signaling.

SF tones can transmit data that only consists of everyday telephone numbers, numbers which only have 0-9 in them. How many pulses are transmitted in one time is part of the number that is dialed. One pulse is 1, two pulses are 2, three pulses are 3 and so on, with 10 pulses being 0.

References 

Telephony signals
S interface. The S interface or S reference point, also known  as S0, is a user–network interface reference point in an ISDN BRI environment, characterized by a four-wire circuit using  144kbit/s (2 bearer and 1 signaling channel; 2B+D) user rate.

The S interface is the connection between ISDN terminal equipment (TE) or terminal adapters (TAs) and an NT1 (network terminator, type 1.) Not all TE or TAs connect externally to an S interface, but instead integrate an NT1 so they can connect directly to a U interface (local loop from central office.)

Contrast to the T interface, which connects between an NT2 (PBX or other local switching device) and NT1. However, the S interface is electrically equivalent to the T interface, and the two are jointly referred to as the S/T interface.

The S interface operates at 4000 48-bit frames per second; i.e., 192kbit/s, with a user portion of 36bits per frame; i.e., 144kbit/s.

See also
 R interface
 T interface
 U interface

References

ITU-T recommendations
Integrated Services Digital Network
Stressed environment. In radio communications, a stressed environment is an environment that is under the influence of extrinsic factors that degrade communications integrity, such as when (a) the beginning communications medium is disturbed by natural or man-made events (such as an intentional nuclear burst), (b) the received signal is degraded by natural or man-made interference (such as jamming signals or co-channel interference), (c) an interfering signal can reconfigure the network, and/or (d) an adversary threatens successful communications, in which case radio signals may be encrypted in order to deny the adversary an intelligible message, traffic flow information, network information, or automatic link establishment (ALE) control information.

References

Radio
System integrity. In telecommunications, the term system integrity has the following meanings: 

 That condition of a system wherein its mandated operational and technical parameters are within the prescribed limits.  
 The quality of an AIS when it performs its intended function in an unimpaired manner, free from deliberate or inadvertent unauthorized manipulation of the system. 
 The state that exists when there is complete assurance that under all conditions an IT system is based on the logical correctness and reliability of the operating system, the logical completeness of the hardware and software that implement the protection mechanisms, and data integrity.

References
 
 National Information Systems Security Glossary

Telecommunications systems
Technology systems
Systems engineering
Computer security
Reliability engineering
Systems control. Systems control, in a communications system, is the control and implementation of a set of functions that:

 prevent or eliminate degradation of any part of the system, 
 initiate immediate response to demands that are placed on the system, 
 respond to changes in the system to meet long range requirements, and
 may include various subfunctions, such as 
 immediate circuit utilization actions, 
 continuous control of circuit quality, 
 continuous control of equipment performance, 
 development of procedures for immediate repair, restoration, or replacement of facilities and equipment, 
 continuous liaison with system users and with representatives of other systems, and 
 the provision of advice and assistance in system use.

References

Telecommunications systems
Technology systems
Technical control facility. In telecommunications, a technical control facility (TCF) is defined by US Federal Standard 1037C as a telecommunications facility, or a designated and specially configured part thereof, that: 

 contains the equipment necessary for ensuring fast, reliable, and secure exchange of information;
 typically includes distribution frames and associated panels, jacks, and switches and monitoring, test, conditioning, and orderwire equipment;
 and allows telecommunications systems control personnel to exercise operational control of communications paths and facilities, make quality analyses of communications and communications channels, monitor operations and maintenance functions, recognize and correct deteriorating conditions, restore disrupted communications, provide requested on-call circuits, and take or direct such actions as may be required and practical to provide effective telecommunications services.

References

Telecommunications systems
Telecommunications infrastructure
Terminal equipment. In telecommunications, the term terminal equipment has the following meanings:

 Communications equipment at either end of a communications link, used to permit the stations involved to accomplish the mission for which the link was established.
 In radio-relay systems, equipment used at points where data are inserted or derived, as distinct from equipment used only to relay a reconstituted signal.
 Telephone and telegraph switchboards and other centrally located equipment at which communications circuits are terminated.

See also
 Customer-premises equipment
 Data terminal equipment, an end instrument that converts user information into signals for transmission or reconverts the received signals into user information

References

Telecommunications equipment
Time-assignment speech interpolation. In telecommunications, a time-assignment speech interpolation (TASI) was an analog technique used on certain long transmission links to increase voice transmission capacity.

TASI was invented by Bell Labs in the early 1960s to increase the capacity of transatlantic telephone cables.  It was one of their first applications requiring electronic switching of voice circuits.

Later digital circuit multiplication equipment included TASI as a feature, not as distinct hardware.

Operation
TASI takes advantage of the fact that in typical person-person conversation, speech in a single direction occurs for approximately 40% of the time, the remaining time being occupied with pauses and/or silence. Statistical analysis demonstrated that for an average voice channel usage of 40%, over 74 speech conversations could be handled using 37 full Duplex speech circuits thereby doubling potential revenue for a small capital outlay relative to a highly expensive cable. e.g. £12.5 million (£263 million as of 2014) cost of the TAT-1 cable on which TASI was implemented.

TASI worked by switching additional users onto any voice channel temporarily idled because an original user has stopped speaking. When the original user resumes speaking, that user would, in turn, be switched to any channel that happened to be idle. The speech detector function is called voice activity detection. Clipping or loss of speech would occur for all conversations that needed to be assigned to an available idle channel and in practice lasted at least 17 ms whilst information required to re-connect both parties was signalled by the TASI control circuits. An additional freezeout period lasting between 0 and 500 ms would depend on the instantaneous loading of voice circuits. In actual use, these delays presented few problems in typical conversations.

One of the issues with using this type of technology was that the users listening on an idled channel can sometimes hear the conversation that has been switched onto it. Generally the sound heard was of very low volume and individual words are not distinguishable. See also crosstalk for a similar phenomenon in telecommunications. Another potential issue was ensuring that non-voice type circuits (e.g. Music or radio type circuits where pauses would occur infrequently) were not routed via TASI speech channels since these could seriously degrade the level of service where callers would encounter frequent clipped speech and breaks in the conversation.

See also
 Talkspurt

References

 
 

Multiplexing
T interface. A T-interface  or T reference point is used for basic rate access in an Integrated Services Digital Network (ISDN) environment.  It is a User–network interface reference point that is characterized by a four-wire, 144 kbit/s (2B+D) user rate.

Other characteristics of a T-interface are:
 it accommodates the link access and transport layer function in the ISDN architecture
 it is located at the user premises
 it is distance sensitive to the servicing Network termination 1
 it functions in a manner similar to that of the Channel service units (CSUs) and the Data service units (DSUs).

The T interface is electrically equivalent to the S interface, and the two are jointly referred to as the S/T interface.

See also
 R interface
 S interface
 U interface

References

Networking hardware
Integrated Services Digital Network
Traffic intensity. In telecommunications networks, traffic intensity is a measure of the average occupancy of a server or resource during a specified period of time, normally a busy hour. It is measured in traffic units (erlangs) and defined as the ratio of the time during which a facility is cumulatively occupied to the time this facility is available for occupancy.  

In a digital network, the traffic intensity is:

where
a is the average arrival rate of packets (e.g. in packets per second)
L is the average packet length (e.g. in bits), and
R is the transmission rate (e.g. bits per second)

A traffic intensity greater than one erlang means that the rate at which bits arrive exceeds the rate bits can be transmitted and queuing delay will grow without bound (if the traffic intensity stays the same). If the traffic intensity is less than one erlang, then the router can handle more average traffic. 

Telecommunication operators are vitally interested in traffic intensity, as it dictates the amount of equipment they must supply.

See also
Teletraffic engineering
IEC 80000-13

References

Teletraffic
Transmission. Transmit or Transmission may refer to:

Medicine, science and technology
 Power transmission
 Electric power transmission
 Transmission (mechanical device), technology that allows controlled application of power
 Automatic transmission
 Manual transmission
 Signal transmission, the process of sending and propagating an analogue or digital information signal
 Analogue transmission - the process of sending and propagating an analogue signal
 Data transmission, the process of sending and propagating digital information
 Signaling (telecommunications) - transmission of meta-information related to the actual transmission
 Monetary transmission mechanism, process by which asset prices and general economic conditions are affected as a result of monetary policy decisions
 Pathogen transmission, the passing of a disease from an infected host individual or group to a particular individual or group
 Cellular signaling - transmission of signals within or between living cells 
 Transmission in genetics, known otherwise as heredity, the transfer of genetic information from genes to another generation
 Transmission (BitTorrent client), a free, open-source and cross-platform BitTorrent client application

Arts and entertainment

Music
 TRNSMT, music festival in Glasgow, Scotland
 Transmission (band), an English experimental/post-rock band
 Transmission (festival), an annual trance music event
 Transmission Communications, an Australian record label

Albums
 Transmission (Gay Dad album) or the title song, 2001
 Transmission (The Tea Party album) or the title song, 1997
 Transmission (Violent Delight album) or the title song, 2003
 Transmissions (Alan Silva and Oluyemi Thomas album), 1993
 Transmissions (Juno Reactor album), 1993
 Transmissions (Starset album), 2014
 Transmissions (Amos Lee album), 2024
 Transmission (Low EP), 1996
 Transmission (Mêlée EP), 2001

Songs
 "Transmission" (song), by Joy Division, 1979
 "Transmission", a mashup by Neil Cicierega from Mouth Silence, 2014
 "Transmissions", a song by the American band Bright from The Albatross Guest House, 1997
 "Transmissions', a song by the Irish band God Is an Astronaut from Origins, 2013

Other media
 Transmission (magazine), a UK literary magazine
 Transmission (novel), a 2005 novel by Hari Kunzru
 Transmission (TV programme), a British music programme
 Transmission, a webcomic by Mark A. Smith, former cartoonist for The Space Gypsy Adventures

Religion and esotericism
 Transmission (esotericism), in Hinduism
 Dharma transmission, in Buddhism, the sequence of lineage holders of a tradition
 Esoteric transmission, in Buddhism, the transmission of empowerment and authorization for a specific practice

See also
 Transmit (file transfer tool), a FTP client for Mac OS X
 Transmitter, a device for propagating electronic signals
 Transmissibility (disambiguation)
 Transmittance of radiation, the propagation of electromagnetic waves through a medium
 Transmissivity (disambiguation)
Transmission block. In telecommunications, the term transmission block has the following meanings:

A group of characters or bits transmitted as a block, unit, message, or packet. It usually includes additional encoded characters for error detection and correction.
In data transmission, a group of records sent, processed, or recorded as a unit.

Some protocols require each transmission block to end with an end-of-message marker. This is often a control character such as End-of-Text (ETX), End-of-Transmission-Block (ETB), or End-of-Transmission (EOT).

Some protocols (especially those requiring ETX) require each transmission block to begin with a Start-of-Text character (STX).

See also
Frame (networking)
Network packet

References

Data transmission
Variable-length buffer. In telecommunications, a variable length buffer or elastic buffer is a buffer into which data may be entered at one rate and removed at another rate without changing the data sequence.  

Most first-in first-out (FIFO)  storage devices are variable-length buffers in that the input rate may be variable while the output rate is constant or the output rate may be variable while the input rate is constant. Various clocking and control systems are used to allow control of underflow or overflow conditions.

See also
Buffer (telecommunication)
Circular buffer

References

Synchronization
Computer memory
Virtual terminal. In open systems, a virtual terminal (VT) is an application service that:

 Allows host terminals on a multi-user network to interact with other hosts regardless of terminal type and characteristics,
 Allows remote log-on by local area network managers for the purpose of management,
 Allows users to access information from another host processor for transaction processing,
 Serves as a backup facility.

PuTTY is an example of a virtual terminal.

ITU-T defines a virtual terminal protocol based on the OSI application layer protocols. However, the virtual terminal protocol is not widely used on the Internet.

See also
 Pseudo terminal for the software interface that provides access to virtual terminals
 Secure Shell
 Telnet
 Terminal emulator for an application program that provides access to virtual terminals
 Virtual console for an analogous concept that provides several local consoles

Sources

Computer terminals
ITU-T recommendations