Definitions beginning with U

unintentional interference - permalink - collapse

All > Technology > Telecommunications

See interference.
ATIS - Cite This Source - This Definition
Browse Related Terms: electromagnetic emission control, emission, emission spectrum, interference, interference emission, parasitic emission, peak spectral emission, quiet zone, telecommunication

uninterruptible power supply (UPS) - permalink - collapse

All > Technology > Storage

Backup power supply that is available when the electrical power fails or drops to unacceptable levels.
NetApp - Cite This Source - This Definition
Browse Related Terms: IPL, Post, power-on self-tests (POST), power supply unit (PSU), PSU, shut down, UPS

All > Technology > Telecommunications

A device that is inserted between a primary power source, such as a commercial utility, and the primary power input of equipment to be protected, e.g., a computer system, for the purpose of eliminating the effects of transient anomalies or temporary outages. Note 1: An UPS consists of an inverter, usually electronic, that is powered by a battery that is kept trickle-charged by rectified ac from the incoming power line fed by the utility. In the event of an interruption, the battery takes over without the loss of even a fraction of a cycle in the ac output of the UPS. The battery also provides protection against transients. The duration of the longest outage for which protection is ensured depends on the battery capacity, and to a certain degree, on the rate at which the battery is drained. Note 2: An UPS should not be confused with a standby generator, which may not provide protection from a momentary power interruption, or which may result in a momentary power interruption when it is switched into service, whether manually or automatically.
ATIS - Cite This Source - This Definition
Browse Related Terms: active device, auxiliary power, power down, power up, primary power, PRS, UPS

Refers to a cell that can only develop in a specific way to produce a certain end result.
DHHS - Cite This Source - This Definition
Browse Related Terms: Autoantibody, autoimmune disease, Memory, Memory cells, tolerance

Unipotent stem cells - permalink - collapse

All > Science > Biotechnology and Genetics > Stem Cell

Stem cells that self-renew as well as give rise to a single mature cell type; e.g., spermatogenic stem cells.
ISSCR - Cite This Source - This Definition
Browse Related Terms: Endogenous stem cells, Fate (of cell progeny), Lineage, Long-term self-renewal, Multipotent, Multipotent stem cells, Side population (SP) stem cell, stem cell

Uniprocessor (UP) - permalink - collapse

All > Technology > Virtualization

A single-processor architecture. See also Symmetric Multiprocessor (SMP).
VMware - Cite This Source - This Definition
Browse Related Terms: HAL (Hardware Abstraction Layer), SMP (Symmetric Multiprocessor), Virtual SMP, VSMP (virtual symmetric multiprocessing)

unique key - permalink - collapse

All > Technology > Telecommunications

Key held only by one crypto-equipment and its associated distribution center.
ATIS - Cite This Source - This Definition
Browse Related Terms: cold start, common fill device, crypto-ignition key (CIK), extraction resistance, fill device, scratch pad store (SPS), single point keying, zeroize

unique stream - permalink - collapse

All > Technology > Storage

A stream whose connection speed, media type, or thinning parameters are different from another stream that is part of the same streaming media presentation.
NetApp - Cite This Source - This Definition
Browse Related Terms: live stream, Microsoft Media Streaming (MMS), MMS, on-demand stream, Real-time Transport Control Protocol (RTCP), RTCP, stream, stream splitting, streaming accelerator, Streaming media, streaming media cache, streaming media presentation, streaming server, thinning, video on demand (VOD), VOD, WMT (Windows Media Technologies)

Unique Visitor - permalink - collapse

All > Technology > Search > SEO / Search Marketing

A real visitor to a web site.

Web servers record the IP addresses of each visitor, and this is used to determine the number of real people who have visited a web site.

If for example, someone visits twenty pages within a web site, the server will count only one unique visitor (because the page accesses are all associated with the same IP address) but twenty page accesses.

See also hit and page view.

I-Search Digest - Cite This Source - This Definition
Browse Related Terms: Hit, HITS, HTML Source, Page View, Referrer, Render, Repeat Visitor, Site Hit, Traffic, Usage Data

Unique visitors - permalink - collapse

All > Technology > Search > SEO / Search Marketing

Unique visitors are a count of individual users who have accessed your web site. It should be noted that the "user session" metric does not yield an accurate unique visitor count, as multiple user sessions can be generated by one unique visitor.
SEO Glossary.com - Cite This Source - This Definition
Browse Related Terms: Frequency, Session, User session, Visit

unisexual - permalink - collapse

All > Science > Biotechnology and Genetics > Food Biotechnology

Higher organisms (animals or plants) possessing either male or female reproductive organs, but not both.
UN Food and Agriculture Organization - Cite This Source - This Definition
Browse Related Terms: bio-engineering, deme, Ecology, Host, mammary gland, metastasis, monophyletic, non-target organism, Nontarget organism, Organ, organic evolution

UNISYS - permalink - collapse

All > Technology > Defense

UNISYS Corporation.
DoD Missile Defense Agency - Cite This Source - This Definition
Browse Related Terms: GTE, ISC, ITT, OAO

Unit - permalink - collapse

All > Recreation > Games > Blackjack

An amount of a bet.
Blackjack Hero - Cite This Source - This Definition
Browse Related Terms: Bet spread, Betting Limits, Flat betting, Kelly betting, Rider bet, Steaming

Unit Control Position - permalink - collapse

All > Science > Weather

The WSR-88D radar operator uses this to control the entire radar system. One of the main things that the radar operator will do at the UCP is change volume scan strategies of the antenna. These volume scan strategies tell the radar how many elevation angles will be used during a single volume scan (a volume scan is the completion of a sequence of elevation angles), and the amount of time it will take to complete that sequence of elevation cuts, each one being a single rotation of the antenna's 1 degree beam at selected elevation angles. The WSR-88D uses 3 scan strategies. They are the following: 14 elevation angles in 5 minutes (this is used during severe weather situations), 9 elevation angles in 6 minutes (this is used when there is precipitation within 248 nautical miles of the radar), and 5 elevation angles in 10 minutes (this is used when there is no precipitation within 248 nautical miles). The radar operator at the UCP can also adjust the radar products and help the users out with their communication problems.
NOAA National Weather Service - Cite This Source - This Definition
Browse Related Terms: CMPLT, ENTR, UCP

unit-distance code - permalink - collapse

All > Technology > Telecommunications

An unweighted code that changes at only one digit position when going from one number to the next in a consecutive sequence of numbers. Note 1: Use of one of the many unit-distance codes can minimize errors at symbol transition points when converting analog quantities into digital quantities. Note 2: An example of a unit-distance code is the Gray code. [From Weik '89]
ATIS - Cite This Source - This Definition
Browse Related Terms: binary code, bitmap, capability code, CO Code (NXX) Exhaust, code element, code structure, coded set, coding scheme, comma-free code, convolutional code, equal-length code, error-detecting code, gold code, Huffman coding, modification detection code, prefix-free code, redundant code

United Nations Framework Convention on Climate Change (UNFCC) - permalink - collapse

All > Science > Climate Change

The international treaty unveiled at the United Nations Conference on Environment and Development (UNCED) in June 1992. The UNFCCC commits signatory countries to stabilize anthropogenic (i.e. human-induced) greenhouse gas emissions to "levels that would prevent dangerous anthropogenic interference with the climate system." The UNFCCC also requires that all signatory parties develop and update national inventories of anthropogenic emissions of all greenhouse gases not otherwise controlled by the Montreal Protocol. Out of 155 countries that have ratified this accord, the United States was the first industrialized nation to do so. See Conference of the Parties, Berlin Mandate, Kyoto Protocol, Montreal Protocol.
EPA - Cite This Source - This Definition
Browse Related Terms: Alliance of Small Island States (AOSIS), Annex I Countries/Parties, Annex I Parties, Berlin Mandate, Conference of the Parties, Joint implementation, Kyoto Protocol, United Nations Framework Convention on Climate Change (UNFCCC), World Meteorological Organization

United Nations Framework Convention on Climate Change (UNFCCC) - permalink - collapse

All > Science > Climate Change

The Convention on Climate Change sets an overall framework for intergovernmental efforts to tackle the challenge posed by climate change. It recognizes that the climate system is a shared resource whose stability can be affected by industrial and other emissions of carbon dioxide and other greenhouse gases. The Convention enjoys near universal membership, with 189 countries having ratified. Under the Convention, governments:
- gather and share information on greenhouse gas emissions, national policies and best practices
- launch national strategies for addressing greenhouse gas emissions and adapting to expected impacts, including the provision of financial andtechnological support to developing countries
- cooperate in preparing for adaptation to the impacts of climate change
The Convention entered into force on 21 March 1994.
EPA - Cite This Source - This Definition
Browse Related Terms: Alliance of Small Island States (AOSIS), Annex I Countries/Parties, Annex I Parties, Berlin Mandate, Conference of the Parties, Joint implementation, Kyoto Protocol, United Nations Framework Convention on Climate Change (UNFCC), World Meteorological Organization

United States Army Corps of Engineers (USACE, Corps) - permalink - collapse

All > Science > Water

The United States Army Corps of Engineers provides quality, responsive engineering services to the nation which includes planning, designing, building and operating water resources and other civil works projects; designing and managing the construction of military facilities for the Army and Air Force; and providing design and construction management support for other Defense and federal agencies.
Bureau of Reclamation - Cite This Source - This Definition
Browse Related Terms: ACER, ACRM, AS, Corps of Engineers., United States Army Corps of Engineers (USACE, Corps)

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unintentional interference - permalink - collapse

uninterruptible power supply (UPS) - permalink - collapse

Union - permalink - collapse

uniparental inheritance - permalink - collapse

unipolar signal - permalink - collapse

Unipotent - permalink - collapse

Unipotent stem cells - permalink - collapse

Uniprocessor (UP) - permalink - collapse

unique key - permalink - collapse

unique stream - permalink - collapse

Unique Visitor - permalink - collapse

Unique visitors - permalink - collapse

unisexual - permalink - collapse

UNISYS - permalink - collapse

Unit - permalink - collapse

Unit Control Position - permalink - collapse

unit-distance code - permalink - collapse

United Nations Framework Convention on Climate Change (UNFCC) - permalink - collapse

United Nations Framework Convention on Climate Change (UNFCCC) - permalink - collapse

United States Army Corps of Engineers (USACE, Corps) - permalink - collapse