Monday, June 23, 2008

Spyware


Spyware is computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user's interaction with the computer, without the user's informed consent.

While the term spyware suggests software that secretly monitors the user's behavior, the functions of spyware extend well beyond simple monitoring. Spyware programs can collect various types of personal information, such as Internet surfing habit, sites that have been visited, but can also interfere with user control of the computer in other ways, such as installing additional software, redirecting Web browser activity, accessing websites blindly that will cause more harmful viruses, or diverting advertising revenue to a third party. Spyware can even change computer settings, resulting in slow connection speeds, different home pages, and loss of Internet or other programs. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is captured under the term privacy-invasive software.

Monday, June 16, 2008

Types of spam


Spam has several definitions, varying by the source.

* Unsolicited bulk e-mail (UBE)—unsolicited e-mail, sent in large quantities.
* Unsolicited commercial e-mail (UCE)—this more restrictive definition is used by regulators whose mandate is to regulate commerce, such as the U.S. Federal Trade Commission.
* Any email message that is fraudulent.
* Any email message where the sender’s identity is forged, or messages sent though unprotected SMTP servers, unauthorized proxies, or botnets (see Theft of service below).

Wednesday, June 11, 2008

Cybernetics

Cybernetics is the interdisciplinary study of the structure of complex systems, especially communication processes, control mechanisms and feedback principles. Cybernetics is closely related to control theory and systems theory.

Example of cybernetic thinking. On the one hand a company is approached as a system in an environment. On the other hand cybernetic factory can be modeled as a control system.

Example of cybernetic thinking. On the one hand a company is approached as a system in an environment. On the other hand cybernetic factory can be modeled as a control system.

Contemporary cybernetics began as an interdisciplinary study connecting the fields of control systems, electrical network theory, mechanical engineering, logic modeling, evolutionary biology and neuroscience in the 1940s.

Other fields of study which have influenced or been influenced by cybernetics include game theory, system theory (a mathematical counterpart to cybernetics), psychology (especially neuropsychology, behavioral psychology, cognitive psychology), philosophy, and architecture.

Monday, June 02, 2008

Cellular automaton

A cellular automaton (plural: cellular automata) is a discrete model studied in computability theory, mathematics, theoretical biology and microstructure modeling. It consists of a regular grid of cells, each in one of a finite number of states. The grid can be in any finite number of dimensions. Time is also discrete, and the state of a cell at time t is a function of the states of a finite number of cells (called its neighborhood) at time t − 1. These neighbors are a selection of cells relative to the specified cell, and do not change (though the cell itself may be in its neighborhood, it is not usually considered a neighbor). Every cell has the same rule for updating, based on the values in this neighbourhood. Each time the rules are applied to the whole grid a new generation is created.