Thursday, August 23, 2007

Reliability

In computer networking, a reliable protocol is one that ensures that reliability properties with respect to the delivery of data to the intended recipient(s), as opposed to an unreliable procedure, which does not guarantee that data will be delivered intact, or that it will be delivered at all. A reliable multicast protocol may ensure consistency on a per-recipient basis, as well as provide strong reliability properties that relate the delivery of data to different recipients, such as e.g. total order, atomicity, or virtual synchrony.
Reliable protocols normally incur more overhead than unreliable protocols, and as a result, are slower and less scalable. This often isn't an issue for unicast protocols, but it may be a difficulty for multicast protocols. TCP, the main protocol used in the Internet today, is a reliable unicast protocol. UDP, often used in computer games or other situation where speed is an issue and the loss of a little fact is not, is an unreliable unicast protocol.

Thursday, August 16, 2007

Security

Security is the condition of being sheltered against danger or loss. In the general sense, security is a perception similar to safety. The nuance between the two is an added emphasis on being protected from dangers that initiate from outside. Individuals or actions that encroach upon the condition of protection are responsible for the breach of security.
The word security in general procedure is synonymous with safety, but as a technical term security means that something not only is protected but that it has been secured. A condition that results from the establishment and maintenance of protective measures that ensures a state of inviolability from hostile acts or influences. With respect to classified matter, the condition that prevents unauthorized persons from having right to use to official information that is safeguarded in the benefit of national security.

Monday, August 06, 2007

The result in cricket

If the team that bats last has all of its batsmen dismissed before it can reach the run total of the differing team, it is said to have lost by (n) runs. If however, the team that bats last exceeds the opposing team's run total before its batsmen are dismissed, it is said to have win by (n) wickets, where (n) is the difference between the number of wickets conceded and 10.If, in a two-innings-a-side match, one team's combined first and second innings total fails to reach its opponent's first innings total, there is no need for the opposing team to bat again and it is said to have won by an innings and (n) runs, where (n) is the variation between the two teams' totals.

If all the batsmen of the team batting last are dismissed with the scores closely equal then the match is a tie; ties are very rare in matches of two innings a side. In the traditional form of the game, if the time allotted for the match expires before either side can win, then the game is a draw. If the match has only a single innings per side, then a highest number of deliveries for each innings is frequently imposed. Such a match is called a limited overs or one-day match, and the side scoring more runs wins anyway of the number of wickets lost, so that a draw cannot occur. If this kind of match is temporarily intermittent by bad weather, then a complex mathematical formula known as the Duckworth-Lewis method is often used to recalculate a new target score. A one-day match can be declared a No-Result if fewer than a up to that time agreed number of overs have been bowled by either team, in circumstances that make normal recommencement of play impossible.