Networks As Discussed By Computer Science Essay

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The World Wide Web is a robust network whose nodes are web content pages that have everything: videos, news, advertisements, maps, books and much more. The nodes are identified using links that allow us to move from one web page to another with every click. Web pages act as switches that keep society up to date with current information.

Barabasi and his research team discovered that connector nodes exist in the web which somehow amass many more links than other nodes. These connector nodes are referred to as hubs and have a wide range of connection links. Barabasi and his coworkers realized that the structure of World Wide Web is composed of highly interlinked hubs.

The topology of the Internet restricts its users' ability to see everything out there. The World Wide Web contains a number of small-scale structures that limit the level to which it can be explored. The internet is comprised of both hardware and software, and other sub-systems. All these work together with the World Wide Web, establishing a connection that makes it possible to share information. People in this diverse system are by no means insignificant. It is because of the genius minds of many scientists that the web exists today. Millions of people work to maintain and monitor components of the system around the clock. DNS servers, giant routers and switches, protocols, web browsers are just some of the vital components and elements of the World Wide Web.

Terrorist Network

The tragic terrorism events of September 11, 2001, caught people's attention worldwide. Barabasi describes terrorist groups as webs without spiders. A network of terrorists is often small and has few resources; it tends to rely on other means such as the hit-and-run acts of violence. Al-Qaeda, was created over a long period. Driven by religious thinking and intolerance to the social and political system, many were attracted to the radical organization over the years. The network extended bit by bit to become a large web without a spider. Al-Qaeda is so well spread and self-sustaining that even removing Osama bin Laden does not eliminate the danger they create. The terrorist network has become a diverse network that constantly changes its system per its current plans. It has many secretive nodes that are hard to trace; it is quite challenging to identify the people who comprise its various nodes. Terrorist networks have objectives and links to social networks, which qualifies them to be called systems.

Hollywood and Six Degrees of Kevin Bacon

Barabasi describes hubs as connectors in scale-free networks. The Bacon factor is a popular bit of entertainment trivia, which demonstrates how any Hollywood star can be linked to Kevin Bacon and other actors within six "moves". This network consists of nodes made up of actors, producers, animators, writers etc. A link is created every time a new video is produced. The Hollywood network offers a clear demonstration of a web, with different hubs and nodes, represented by human beings, and links represented by the human relationships. Can we say that human beings are components in some way and that they satisfy a common purpose? The principle of the Hollywood network is to produce films. However, not all characters act together in a single movie. The Hollywood network is thus not a system.

Differences between "scale-free" networks and "random" networks; how each type of network is formed and examples

Random connections depict that nodes in networks share an almost even number of links to other nodes and that the representation of these nodes follows the Poisson distribution. Mathematicians Erdos and Renyi made this discovery. A graphical outlook of networks describes how nodes and hubs obey normal distribution rules. Nodes and hubs form structural components in a scale-free network that is robust and vulnerable. A scale-free network can easily cope with changes in the environment since the network is decentralized. In case one hub is removed, the network is not scrambled. However, removing several hubs would cause a scatter in the network.

The differences between a scale-free network and a random network are key, but both scale-free and randomly distributed networks can be considered as "small world" networks. This means that it does not take many steps from one node to another. Equally, in scale-free and random networks, with or without connected nodes, it may not take many steps for a node to make a connection with another node. There is an enormous chance that, in scale-free networks, a number of transactions would be guided via one of the well-linked hub nodes - one similar to the Google or Yahoo web portals. Because of these differences, the two types of networks act differently as they break down. Matlis (2002) states that the connectedness of a randomly distributed network decays progressively as nodes fail, slowly breaking into tiny, divided domains that are unable to communicate.

C:\Documents and Settings\Administrator\My Documents\My Pictures\Scale-free_network_sample.png

The figures above show the differences between random and scale-free architecture.

Similarities and differences between the internet and traditional human-designed systems

The internet is a robust network with nodes that spread all over the world. Email, browsing, and podcasting are done by few clicks and some typing. The Internet, being disorganized and cluttered, is probably the messiest human made system ever. There is no responsible hand, no single company in charge of the Internet's functions, and there is no true map of structure and how it operates. This systems characteristic differs with most common systems designed by humans.

Comparing the internet to the human-designed traffic system, we can depict clear similarities and differences. The traffic system has clear laws that drivers have to follow; if they don't, they risk tickets, fines or even going to jail. On the contrary, the internet has no such restrictions; a person can navigate through the internet wherever he or she feels like.

Traffic systems all over the world usually have principal regulations, meaning that there is a central organization that is in charge of delegating important tasks to different companies such as road workers and speed controllers (police). All of these organizations have to follow these rules and laws. In contrast, the Internet has no central regulation; everyone is "connected", whenever it is mutually beneficial or not.

One main similarity between the traffic system and the Internet is the redundancy of losing links or "roads". As described previously in this paper concerning the web, removing one link between two nodes does not cripple the nodes' ability to communicate. There are always alternative nodes with links to that computer or address. Traffic systems have the same feature. Closing one road to a city doesn't make the city inaccessible; you can always choose another road. In the same way, removing a large city does not prevent a driver from accessing other cities, but removing ten main cities does affect the drivers ability to navigate to other cities nearby. The same happens on the Internet.

Design Implications

The first intention of the Internet was to connect and allow file allocation between computers within a military area. The message research technology ended up with the development of the Internet Protocol, the basis for computer network communication. Since the introduction of ARPANET, the Internet has grown to a magnificent network, not just linking computers within a military area, but linking everybody with an Internet connection. The brilliance of the Internet's structure is that is almost totally independent. It continues to grow without anybody regulating it. The Internet is a vibrant, multi-core system. If one hub or core fails to function, internet traffic going through that hub will be redirected to a different core, allowing them to proceed with their request without losing track. Making the design of systems as dynamic as possible is important for future systems. This may reduce the safeguarding cost significantly, and making upgrades will demand minute or no attention.