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Subject: cross differentiatuing Пожалуйста, помогите перевести.Выражение встречается в следующем контексте: Заранее спасибо |
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Newton-Raphson correction By cross differentiating the equilibrium equations they may be combined to eliminate the mean stress where H is identically zero for a set of stresses in equilibrium and is taken as a measure of the error for a set of stresses which are not in equilibrium. An initial set of the stream function value *F0 is estimated and the corresponding values of Я0 determined. At each finite difference grid point Т is then perturbed by a small amount, and the resulting effect on Я evaluated at every other grid point. The changes in Я are confined to a region 'downstream* and extending a small distance to either side of the perturbed point. By repeating this process at every grid point an N x N matrix (where N is the number of grid points in the finite difference конечноразностная сетка) of 'partial derivatives' of Я with respect to У can be calculated. By multiplying the vector — HQ by the inverse of this matrix the correction to Т which is needed to eliminate the error approximately (or exactly in the case of a linear problem) may be determined. The calculation is then repeated with the new set of У values until the error is reduced to a satisfactory level. Testing of this approach with some simple problems showed that as long as the perturbed flow does not include any regions in which plastic deformation occurs then the method converges very rapidly on the correct solution. This is because the equations are purely linear in these cases. If, however, there is any plastic deformation, as is the case for all realistic cone penetration problems, then the method does not converge (even when acceleration or deceleration techniques are also adopted). |
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Во-вервых cross differentiaTING Во-вторых, думаю, что это взятие перекрестных производных |
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Ага, контекст прибыл. По сабжу - это скорее просто взятие частных производных. Так будет точнее correction это определенно модификация метода Ну и почитайте немного сами. Метож достаточно распространенный, о нем много пишут, например |
| спасибо Annaa большое за помощ |
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