Hub is a concept in network science which refers to a node with a number of links that greatly exceeds the average. Emergence of hubs is a consequence of a scale-free property of networks. While hubs cannot be observed in a random network, they are expected to emerge in scale- free networks. Uprise of hubs in scale-free networks is associated with power- law distribution. Hubs have a significant impact on the network topology. Hubs can be found in many real networks, such as Brain Network or Internet.
Definition
Hub is a component of a network, a high- degree node. It refers to a node that has significantly bigger number of links in comparison with other nodes in the network. Number of links (degrees) for hub in a scale-free network is much higher than the biggest node in a random network would have, keeping the size N of the network and average degree <k> constant. Existence of hubs is the biggest difference between random networks and scale-free networks. In random networks the number of degrees k is comparable for every node and therefore it is not possible for hubs to emerge. In scale-free networks a few nodes (hubs) have a high degree k while the rest of the nodes has a small number of links.
Discovery Family (formerly Discovery Kids and the Hub Network) is an American digital cable and satellite television channel owned by Discovery Communications, marketed as a family-friendly network with a mix of original and acquired children's programs, such as Hasbro's My Little Pony: Friendship is Magic, Littlest Pet Shop and Transformers themed shows, along with family-oriented science and nature-themed programs.
The network was launched on October 7, 1996, as Discovery Kids, a spin-off of Discovery Channel that featured science, nature, and adventure-themed programs aimed towards children aged between 6 and 11. In April 2009, Hasbro announced a joint venture with Discovery to re-launch Discovery Kids as The Hub (later Hub Network) on October 10, 2010; Hasbro handled programming, while Discovery handled distribution and advertising sales. The Hub was intended to be a general, youth-oriented network with a "diverse" lineup, primarily featuring programming adapted from Hasbro franchises (such as Transformers, its board games, My Little Pony, Pound Puppies, and Littlest Pet Shop), along with other, family-oriented programs such as sitcom reruns and films.