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Linear approximation

About: Linear approximation is a research topic. Over the lifetime, 3901 publications have been published within this topic receiving 74764 citations.


Papers
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Proceedings ArticleDOI
28 Feb 1994
TL;DR: A novel method for the estimation of yield of integrated circuits based on a two step linear approximation of circuit performance is proposed and a new algorithm for yield optimization is presented, based on the random direction stochastic approximation.
Abstract: A novel method for the estimation of yield of integrated circuits based on a two step linear approximation of circuit performance is proposed. By using this method, only one complete circuit simulation is needed for the estimation of yield. A new algorithm for yield optimization is also presented. It is based on the random direction stochastic approximation and does not require the evaluation of yield gradients. Examples are given to demonstrate the efficiency of the algorithm. >

33 citations

Journal Article
TL;DR: In this article, a modified Born approximation based on the extended Born approximation is proposed for the inversion of large contrast dielectric objects buried in a lossy earth using the idea of backconditioner and lumped-mass approximation.
Abstract: Linear inverse scattering method based on the Born approximation has found wide applications in the on-site detection of buried objects, such as in diffraction tomography. However, the Born approximation becomes invalid when the contrast of targets is high, in which the multiple-scattering effect within the target is more important. To avoid solving the nonlinear inverse scattering problem for large-contrast objects, quasi-linear and modified quasi-linear approximations are proposed based on the extended Born approximation. In this paper, new formulations are derived for the inversion of large-contrast dielectric objects buried in a lossy earth using the idea of backconditioner and lumped-mass approximation. We have shown that the zeroth-order form of such formulations is just the well-known Born approximation, and the first-order form is completely equivalent to the extended Born approximation-based quasi-linear approximation. Hence, high-order approximations are proposed in this paper, which are given in closed forms. Using such approximations, good resolution images can be obtained for large-contrast objects by only solving a linear inverse scattering integral equation. Reconstruction examples show the validity and efficiency of the proposed formulae.

33 citations

Proceedings ArticleDOI
12 May 2008
TL;DR: In this paper, it was shown that the power spectrum SYS of the nonlinear noise source YS is a robust characteristic, making its use in the daily engineering practice very attractive.
Abstract: In many engineering applications, linear models are preferred, even if it is known that the system is nonlinear. A large class of nonlinear systems, excited with a 'Gaussian' random excitation, can be represented as a linear system GBLA plus a nonlinear noise source YS. The nonlinear noise source represents that part of the output that is not captured by the linear approximation. It was shown before that the GBLA is an invariant for a wide class of excitations with a user specified power spectrum. In this paper it is shown that also the power spectrum SYS of the nonlinear noise source YS is a robust characteristic. This shows that the alternative 'linear representation' of a nonlinear system is a robust one, making its use in the daily engineering practice very attractive.

33 citations

Journal ArticleDOI
TL;DR: An improved dual simplex algorithm for the solution of the discrete linear L 1 approximation problem is described, which has the advantage that in case of ill-conditioned problems, the basis matrix can lend itself to triangular factorization and can thus ensure a stable solution.
Abstract: An improved dual simplex algorithm for the solution of the discrete linear L 1 approximation problem is described. In this algorithm certain intermediate iterations are skipped. This method is comparable with an improved simplex method due to Barrodale and Roberts, in both speed and number of iterations. It also has the advantage that in case of ill-conditioned problems, the basis matrix can lend itself to triangular factorization and can thus ensure a stable solution. Numerical results are given.

33 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20237
202229
202197
2020134
2019124
2018147