A* algorithm
A member of the class of best-first heuristic search techniques that attempt to find a “best” path from a given start node to a designated goal node in a problem graph. An evaluation function is used ...
Aalen model
A linear regression model describing the manner in which the expected value of a response variable, Z(t), depends on explanatory variables X1(t),…, Xk(t) with time-dependent coefficients β0(t), ...
Abandonment
A term used to describe the user of the Internet who stops some process they are involved in and does not return to it. For example a user who has purchased some items, partially filled their ...
abelian group
Suppose that G is a group with the operation ￮. Then G is abelian if the operation ￮ is commutative; that is, if, for all elements a and b in G, a ￮ b=b ￮ a.
Abel's test
A test for the convergence of an infinite series which states that if ∑a n is a convergent sequence, and {b n} is monotically decreasing, i.e. b n+1≤b n for all n, then ∑a n b n is also convergent.
ABEND
Acronym for ABnormal END of task. Normally this occurs when a computer crashes or a communication link fails.
ablative
Designating an optical recording technique in which the heat generated by the recording beam melts or vaporizes a small area of the recording medium, leaving the underlying layer (with a different ...
abnormal termination
A termination to a process brought about by the operating system when the process reaches a point from which it cannot continue, e.g. when the process attempts to obey an undefined instruction. In ...
ABONE
The Asian-Pacific Internet backbone network that connects users throughout East and South Asia without the need to send data via European or North American networks.
abort
(of a process) To undergo or cause abnormal termination. Abortion may be a voluntary act by the process, which realizes that it cannot reach a successful conclusion, or may be brought about by the ...
above
Greater than. The limit of a function at a from above is the limit of f(x) as x → a for values of x>a. It is of particular importance when f (x) has a discontinuity at a, i.e. where the limits from ...
above the fold
When a Web page is displayed in a browser the area of the page that is displayed is referred to as being above the fold. The contents that lie below are known as below the fold. The term is derived ...
Abraham de Moivre
(1667–1754; b. Vitry, France; d. London, England)French mathematical prodigy. De Moivre studied at U Sedan when aged eleven, and later at U Saumur and the Sorbonne. In 1688 he emigrated to London to ...
Abraham Wald
(1902–50; b. Cluj, Romania; d. Travancore, India)Hungarian geometer and statistician. Wald gained his PhD in geometry in 1931 from U Vienna. In 1938, on the Nazi seizure of Austria, he moved to ...
absolute address
A unique number that specifies a unique location within the address space where an operand is to be found/deposited, or where an instruction is located. It generally specifies a memory location but ...
absolute code
Program code in a form suitable for direct execution by the central processor, i.e. code containing no symbolic references. See also machine code.
absolute difference
The absolute value of the difference between two numbers. See also mean deviation.
absolute frequency
The number of occurrences of an event. For example, if a die is rolled 20 times and 4 sixes are observed the absolute frequency of sixes is 4 and the relative frequency is 4/20.
