|
Flash-cut
A flash cut, also called a flash cutover, is an immediate change in a complex system, with no phase-in period. In the United States, some telephone area codes were split or overlaid immediately, rather than being phased in with a permissive dialing period. An example is telephone area code 213, which serves downtown Los Angeles and its immediate environs, split in January 1951 into 213 and 714 all at once. Another example is an immediate switch from an analog television channel to a digital television channel on the same frequency, where the two cannot operate in parallel without interference. A flash cut can also define a procedure in which multiple components of computer infrastructure are upgraded in multiple ways, all at once, with no phase-in period. In film, an extremely brief shot, sometimes as short as one frame, which is nearly subliminal in effect. Also a series of short staccato shots that create a rhythmic effect. See also * Big bang adoption * Flag day (sof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined world-wide, as well as within each of the administrative regions of the public switched telephone network (PSTN), and in private telephone networks. In public numbering systems, geographic location typically plays a role in the sequence of numbers assigned to each telephone subscriber. Many numbering plan administrators subdivide their territory of service into geographic regions designated by a prefix, often called an area code or city code, which is a set of digits forming the most-significant part of the dialing sequence to reach a telephone subscriber. Within such regions designated by area codes, locally unique telephone number are assigned based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlay Plan
In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to the same geographic numbering plan area (NPA). Area code overlays are implemented in territories of the North American Numbering Plan (NANP) to mitigate exhaustion of central office codes in growth areas. The method has been in use since 1992, and has been the exclusive method of area code relief since 2007. History From the inception of the North American Numbering Plan in 1947 until 1992, the only method of introducing new area codes was the area code split. It divided an existing numbering plan area (NPA) into multiple regions, one of which retained the existing area code. The other parts were each assigned a new NPA code. The retaining area was usually the historically more established or developed place, and required no numbering changes. It gained numbering capacity by acquiring the central office codes of the other areas, because those were delegated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permissive Dialing
In North America, permissive dialing is the ability to make phone calls in an area subject to a newly introduced area code by using both the new and preexisting dialing methods. When an area is given a new area code under a split plan, the area's previous area code would no longer be valid for calls in the area, so calls to numbers using the old area code will not work. To alleviate misdialing frustration, the local routing can be set up such that both the old and new area codes will work for the same telephone exchange. During this period, the local numbering authority must not reassign the area's existing exchanges to the remaining area of the old area code, nor vice versa. At the end of the permissive dialing period, the old area code is no longer valid for numbers in the affected area. Under an overlay plan, permissive dialing refers to the ability to continue to connect calls via 7-digit dialing while also making 10-digit dialing valid. Again, the affected area must not int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 213
Area codes 213, 323, and 738 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of California. They are assigned in an overlay complex to a numbering plan area (NPA) that comprises, roughly, the area of downtown Los Angeles City, as well as several southeast Los Angeles County cities, such as Bell and Huntington Park. Area code 213 was one of the original North American area codes of 1947 and 323 was created in an area code split of 213 in 1998. This was the fifth split of 213 and left it serving only downtown Los Angeles and immediately adjoining neighborhoods. In 2017, the two NPAs were recombined in the overlay. Area code 738 was selected as an additional overlay area code, activated in November 2024. History In 1947, when the American Telephone and Telegraph Company (AT&T) devised the first nationwide telephone numbering plan and assigned the original North American area codes, the state of California was divided into three numbering pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles
Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, cultural center of Southern California. With an estimated 3,878,704 residents within the city limits , it is the List of United States cities by population, second-most populous in the United States, behind only New York City. Los Angeles has an Ethnic groups in Los Angeles, ethnically and culturally diverse population, and is the principal city of a Metropolitan statistical areas, metropolitan area of 12.9 million people (2024). Greater Los Angeles, a combined statistical area that includes the Los Angeles and Riverside–San Bernardino metropolitan areas, is a sprawling metropolis of over 18.5 million residents. The majority of the city proper lies in Los Angeles Basin, a basin in Southern California adjacent to the Pacific Ocean in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 714
Area codes 714 and 657 are telephone area codes in the North American Numbering Plan (NANP) for the southern part of the U.S. state of California. The numbering plan area comprises northern Orange County, a portion of Los Angeles County, and the Sleepy Hollow and Carbon Canyon areas of Chino Hills in San Bernardino County. Area code 714 was assigned to a part of numbering plan area 213 in 1951, and 657 was added in 2008 to form an overlay complex. History In 1947, when the American Telephone and Telegraph Company (AT&T) devised the first nationwide telephone numbering plan and assigned the original North American area codes, the state of California was divided into three numbering plan areas: 213, 415, and 916, for the southern, central, and northern parts of the state, respectively. The area served by 213 extended from Mexican border to the Central Coast. Starting in the 1950s, Southern California experienced rapid expansion of telephone service, requiring area code 213 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Television
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, instantaneous phase and frequency, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes Noise (video), snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below digital cliff, a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television. All broadcast television systems used analog signals before the arrival of DTV. Motivated by the lower bandwidth requ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using Digital signal, digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio (commonly 16:9) in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same Bandwidth (signal processing), bandwidth as a single analog channel, and provides many new features that analog television cannot. A digital television transition, transition from analog to digital broadcasting began around 2000. Different digital television broadcasting st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bang Adoption
Big bang adoption or direct changeover is when a new system is adopted instantly, with no transition period between the old and new systems.Eason, 1988 When a new system needs to be implemented in an organization, there are three different ways to adopt this new system: the big bang adoption, phased adoption and parallel adoption. In case of parallel adoption the old and the new system are running parallel, so all the users can get used to the new system, and meanwhile do their work using the old system. Phased adoption means that the adoption will happen in several phases, so after each phase the system is a little nearer to be fully adopted. With the big bang adoption, the switch between using the old system and using the new system happens at one single date, the so-called instant changeover of the system. Everybody starts to use the new system at the same date and the old system will not be used anymore from that moment on. The advantage of a big bang adoption is that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flag Day (software)
A flag day, as used in system administration, is a change which requires a complete restart or conversion of a sizable body of software or data. The change is large and expensive, and—in the event of failure—similarly difficult and expensive to reverse. The situation may arise if there are limitations on backward compatibility and forward compatibility among system components, which then requires that updates be performed almost simultaneously (during a "flag day cutover") for the system to function after the upgrade. This contrasts with the method of gradually phased-in upgrades, which avoids the disruption of service caused by ''en masse'' upgrades. This systems terminology originates from a major change in the Multics operating system's definition of ASCII, which was scheduled for the United States holiday, Flag Day, on June 14, 1966. Another historical flag day was January 1, 1983, when the ARPANET changed from NCP to the TCP/IP protocol suite. This major change required ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dagen H
(H-day), today usually called "" (), was on 3 September 1967, the day on which Sweden switched from Left- and right-hand traffic, driving on the left-hand side of the road to the right. The "H" stands for "''Högertrafik''", the Swedish language, Swedish word for right-hand traffic. It was by far the largest logistical event in Sweden's history. Background There were various arguments for the change: *All neighbouring countries drove on the right, including Norway and Finland, with which Sweden shares land borders, with 5 million vehicles crossing annually. *More than 90 percent of Swedes drove left-hand-drive vehicles, and this led to many head-on collisions when passing on narrow two-lane highways, along with difficulty changing lanes. City buses were among the very few vehicles that conformed to the normal opposite-steering wheel rule, being right-hand-drive (RHD). However, the change was unpopular; in a 1955 Swedish driving side referendum, 1955 referendum, 83 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
