| programming, linear | A technique of operations research for solving certain kinds of problems involving many variables where a best value or set of best values is to be found. It is most likely to be feasible when the quantity to be optimised, sometimes called the objective function, can be stated as a mathematical expression in terms of the various activities within the system, and when this expression is simply proportional to the measure of the activities, i.e., is linear, and when all the restrictions are also linear. It is different from computer programming, although problems using linear programming techniques may be programmed on a computer. (12 Dec 1998) |
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| non-linear | Not linear. (05 Dec 1998) |
| superficial linear keratitis | Spontaneous, painful keratitis with epithelial erosion and folds in Bowman's membrane. (05 Mar 2000) |
| linear | Pertaining to or resembling a line. Origin: L. Linearis (18 Nov 1997) |
| linear absorption coefficient | That fraction of ionizing radiation absorbed in a unit thickness of a substance or tissue. See: absorption coefficient. (05 Mar 2000) |
| linear acceleration | The rate of change of velocity without a change in direction; e.g., when the speed of an aircraft increases while flying a straight pathway. (05 Mar 2000) |
| linear accelerator | <apparatus> A sophisticated external beam radiotherapy machine which has the capabilities of focussing irradiation (although not very finely). Acronym: LinAC (16 Dec 1997) |
| linear amputation | Amputation performed by a circular incision through the skin, the muscles being similarly divided higher up, and the bone higher still. Synonym: guillotine amputation, linear amputation. (05 Mar 2000) |
| linear atrophy | Bands of thin wrinkled skin, initially red but becoming purple and white, which occur commonly on the abdomen, buttocks, and thighs at puberty and/or during and following pregnancy, and result from atrophy of the dermis and overextension of the skin; also associated with ascites and Cushing's syndrome. Synonym: atrophoderma striatum, lineae albicantes, lineae atrophicae, linear atrophy, stretch marks, stria, striae atrophicae, striate atrophy of skin, traction atrophy, vergeture. (05 Mar 2000) |
| linear dichroism | <chemistry> Differential absorption of right hand and left hand circularly polarized light resulting from molecular asymmetry involving a chromophore group. Circular dichroism is used to study the conformation of proteins in solution. (18 Nov 1997) |
| linear energy transfer | <radiobiology> Average amount of energy lost per unit of particle track length and expressed in keV um-1. Acronym: LET (16 Dec 1997) |
| linear epidermal nevus | A congenital systematised linear nevus limited to one side of the body or to portions of the extremities on one side; lesions are often extensive, forming wave-like bands on the trunk and spiraling streaks on the extremities. Synonym: linear epidermal nevus. (05 Mar 2000) |
| linear fracture | A fracture running parallel with the long axis of the bone. Synonym: fissured fracture. (05 Mar 2000) |
| linear IgA bullous disease in children | A rare self-limiting bullous disease, chiefly of the trunk, perioral, and pelvic areas, with onset in the first decade, successively less severe recurrences, and total remission at adolescence; linear epidermal basement membrane zone deposit of IgA is found in involved and in normal skin. Synonym: linear IgA bullous disease in children. (05 Mar 2000) |
| linear models | Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression. (12 Dec 1998) |