This paper presents a new barrier method for convex programming. The method involves an optimization transfer principle. Instead of minimizing the objective function f(x) directly, one minimizes the amended function f(x)− μ P i x i lnxi to produce the next iterate x n+1 from the current iterate x. If the feasible region is contained in the unit simplex, then this strategy forces a decrease in f...

BACKGROUND AND PURPOSE Increased blood-brain barrier permeability is believed to be associated with complications following acute ischemic stroke and with infarct expansion. Measurement of blood-brain barrier permeability requires a delayed image acquisition methodology, which prolongs examination time, increasing the likelihood of movement artefacts and radiation dose. Existing quantitative me...

The objective of this study was to propose a suitable electrode disposition and shape for iontophoretic drug delivery systems in consideration of a reduction in skin barrier function and a distribution of current density. The reduction in barrier function was evaluated with our proposed method, which measured the resistance in the short term. The distribution was estimated using an electromagne...

For a single potential barrier, the barrier penetrability can be inverted based on the WKB approximation to yield the barrier thickness. We apply this method to heavy-ion fusion reactions at energies well below the Coulomb barrier and directly determine the inter-nucleus potential between the colliding nuclei. To this end, we assume that fusion cross sections at deep subbarrier energies are gov...

Interest in linear programming has been intensified recently by Karmarkar 's publication in 1984 of an algorithm that is claimed to be much faster than the simplex method for practical problems. We review classical barrier-function methods for nonlinear programming based on applying a logarithmic transformation to inequality constraints. For the special case of linear programming, the t ransfor...