| discrete random variable | A random variable that may assume a countable number of values, each with a probability strictly greater than zero. (05 Mar 2000) |
|---|
| mixed discrete-continuous random variable | <statistics> A random variable that may assume some values with probabilities and others with probability densities. For example, in a 35-year-old man with familial polyposis of the colon, the distribution of time until malignant disease occurs consists of a probability that he already has cancer (which would be assigned the waiting time 0), a probability density of developing it in the future and a probability that he will die of some other cause before he develops cancer. (05 Mar 2000) |
|---|---|
| discrete variable | A variable that may assume only a countable (usually finite) number of values. (05 Mar 2000) |
| random variable | A variable that may assume a set of values, each with fixed probabilities or probability densities (its distribution), in such a way that the total probability assigned to the distribution is unity; the random variable may be discrete, continuous, or mixed discrete-continuous. (05 Mar 2000) |
| continuous random variable | Continuous variable that may randomly assume any value in its domain but any particular value has no probability of occurring, only a probability density. (05 Mar 2000) |
| discrete | 1. Separate; distinct; disjunct. 2. Disjunctive; containing a disjunctive or discretive clause; as, "I resign my life, but not my honor," is a discrete proposition. 3. <botany> Separate; not coalescent; said of things usually coalescent. Discrete movement. See Concrete movement of the voice, under Concrete, Discrete proportion, proportion where the ratio of the means is different from that of either couplet; as, 3:6::8:16, 3 bearing the same proportion to 6 as 8 does to 16. But 3 is not to 6 as 6 to 8. It is thus opposed to continued or continual proportion; as, 3:6::12:24. Discrete quantity, that which must be divided into units, as number, and is opposed to continued quantity, as duration, or extension. Origin: L. Discretus, p. P. Of discernere. See Discreet. Source: Websters Dictionary (01 Mar 1998) |
| discrete character | Classifiable character that is also countable (e.g., number of progeny, number of teeth). Synonym: discrete character. (05 Mar 2000) |
| discrete smallpox | The usual form in which the lesions are separate and distinct from each other. (05 Mar 2000) |
| discrete time model | <epidemiology> A model in which the system jumps from one state to the next at fixed intervals or timesteps. These difference models are simple to understand but often difficult to analyse; Contrast continuous time models. The parameters in such a model refer to the amount of change over the finite timestep; they are sometimes referred to as finite rates. In a (rather precise) sense, a differential equation is what you eventually get from a difference equation when you let the timestep get smaller and smaller and smaller. (05 Dec 1998) |
| variable | One of a battery of antigenicdeterminants expressed by a microorganismto elude immune detection. (09 Oct 1997) |
| variable antigen | <immunology> Term usually applied to the surface antigens of those parasitic or pathogenic organisms that can alter their antigenic character to evade host immune responses. (See antigenic variation). (18 Nov 1997) |
| variable deceleration | Transient foetal bradycardia usually denoting compression of the umbilical cord which may occur at any time in relation to a uterine contraction. (05 Mar 2000) |
| variable gene | <molecular biology> Those regions in the amino acid sequence of both the heavy and the light chains of immunoglobulins where there is considerable sequence variability from one immunoglobulin to other of the same class, in contrast to constant sequence (C) regions. The V regions are associated with the antigen binding areas. They contain hypervariable regions of particularly high sequence diversity. (18 Nov 1997) |
| variable region | <molecular biology> Those regions in the amino acid sequence of both the heavy and the light chains of immunoglobulins where there is considerable sequence variability from one immunoglobulin to other of the same class, in contrast to constant sequence (C) regions. The V regions are associated with the antigen binding areas. They contain hypervariable regions of particularly high sequence diversity. (18 Nov 1997) |
| variable surface glycoprotein | <protein> One of a battery of antigenicdeterminants expressed by a microorganism to elude immune detection. (09 Oct 1997) |
| random | 1. Force; violence. "For courageously the two kings newly fought with great random and force." (E. Hall) 2. A roving motion; course without definite direction; want of direction, rule, or method; hazard; chance; commonly used in the phrase at random, that is, without a settled point of direction; at hazard. "Counsels, when they fly At random, sometimes hit most happily." (Herrick) "O, many a shaft, at random sent, Finds mark the archer little meant !" (Sir W. Scott) 3. Distance to which a missile is cast; range; reach; as, the random of a rifle ball. 4. <chemical> The direction of a rake-vein. Origin: OE. Randon, OF. Randon force, violence, rapidity, a randon, de randon, violently, suddenly, rapidly, prob. Of German origin; cf. G. Rand edge, border, OHG. Rant shield, edge of a shield, akin to E. Rand, n. See Rand. Going at random or by chance; done or made at hazard, or without settled direction, aim, or purpose; hazarded without previous calculation; left to chance; haphazard; as, a random guess. "Some random truths he can impart." (Wordsworth) "So sharp a spur to the lazy, and so strong a bridle to the random." (H. <medicine> Spencer) Random courses, stonework consisting of stones of unequal sizes fitted together, but not in courses nor always with flat beds. Source: Websters Dictionary (01 Mar 1998) |