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Ultranet Logo
Ultranet can refer to one of the following: * Ultranet (company), a former telecommunications firm in Massachusetts, United States * Ultranet (math) In mathematics, more specifically in general topology and related branches, a net or Moore–Smith sequence is a function whose domain is a directed set. The codomain of this function is usually some topological space. Nets directly generalize ..., a term in topology * , a HVDC-project in Germany * Ultranet (product), an online environment developed by the Department of Education and Early Childhood Development in Victoria, Australia {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultranet (company)
RCN Corporation, originally Residential Communications Network, founded in 1993 and based in Princeton, New Jersey, was the first American facilities-based ("overbuild") provider of bundled cable telephony, cable television, and internet service delivered over its own hybrid fiber-coaxial local network as well as dialup and DSL Internet service to consumers in the Boston, Chicago, Los Angeles, New York City, the Lehigh Valley in eastern Pennsylvania, and Washington, D.C. areas. In the late 1990s RCN bought the internet service providers Erol's for sum $83.5 million, and Ultranet for sum $27 million making RCN the largest northeast regional ISP at the time. , RCN claimed over 424,000 domestic customers and 130 cable franchises. RCN's network offered coverage to approximately 3.8 million people, making it the 11th largest provider of cable Internet access in the U.S. Its operations, as well as sister companies Grande Communications, and Wave Broadband are handled under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultranet (math)
In mathematics, more specifically in general topology and related branches, a net or Moore–Smith sequence is a function whose domain is a directed set. The codomain of this function is usually some topological space. Nets directly generalize the concept of a sequence in a metric space. Nets are primarily used in the fields of analysis and topology, where they are used to characterize many important topological properties that (in general), sequences are unable to characterize (this shortcoming of sequences motivated the study of sequential spaces and Fréchet–Urysohn spaces). Nets are in one-to-one correspondence with filters. History The concept of a net was first introduced by E. H. Moore and Herman L. Smith in 1922. The term "net" was coined by John L. Kelley. The related concept of a filter was developed in 1937 by Henri Cartan. Definitions A directed set is a non-empty set A together with a preorder, typically automatically assumed to be denoted by \,\le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |