This article is about the topic in optimization. For the topic in dynamical systems, see Barrier certificate.
In constrained optimization, a field of mathematics, a barrier function is a continuous function whose value increases to infinity as its argument approaches the boundary of the feasible region of an optimization problem.[1][2] Such functions are used to replace inequality constraints by a penalizing term in the objective function that is easier to handle. A barrier function is also called an interior penalty function, as it is a penalty function that forces the solution to remain within the interior of the feasible region.
The two most common types of barrier functions are inverse barrier functions and logarithmic barrier functions. Resumption of interest in logarithmic barrier functions was motivated by their connection with primal-dual interior point methods.
^Nesterov, Yurii (2018). Lectures on Convex Optimization (2 ed.). Cham, Switzerland: Springer. p. 56. ISBN 978-3-319-91577-7.
^Nocedal, Jorge; Wright, Stephen (2006). Numerical Optimization (2 ed.). New York, NY: Springer. p. 566. ISBN 0-387-30303-0.
In constrained optimization, a field of mathematics, a barrierfunction is a continuous function whose value increases to infinity as its argument approaches...
The secretion of various molecules into the lumen reinforces the barrierfunction on the extra-epithelial side, while a variety of immune cells provide...
allows nutrients to pass through the gut, while also maintaining a barrierfunction to keep potentially harmful substances (such as antigens) from leaving...
formation of an extracellular matrix that is an integral part of the skin barrierfunction. In normal skin, the rate of keratinocyte production equals the rate...
hydrogen atoms. Some sources describe the mere penetration of a wave function into the barrier, without transmission on the other side, as a tunneling effect...
causes the amnion to be passively attached to the chorion. The chorion functions to separate the amnion from the maternal decidua and uterus. The placenta...
placental development. The syncytiotrophoblast contributes to the barrierfunction of the placenta. The placenta grows throughout pregnancy. Development...
law. However, in this case the barrier height does not depend on We. The barrier height now depends on the work function of the collector, as well as any...
W, et al. (2019-12-20). "Innate Lymphoid Cells: Regulators of Gut BarrierFunction and Immune Homeostasis". Journal of Immunology Research. 2019: 2525984...
CSF-brain barrier at the level of the pia mater, but only in the embryo. Similar to the blood–brain barrier, the blood–CSF barrierfunctions to prevent...
regulate the paracellular barrierfunction. Tight junctions provide endothelial and epithelial cells with barrierfunction, which can be further subdivided...
A barrier certificate or barrierfunction is used to prove that a given region is forward invariant for a given ordinary differential equation or hybrid...
of epithelial cells varies according to the function of that region. Important for the barrierfunction of intestinal epithelium, its cells are joined...
products to treat xerosis. Some moisturizers tend to weaken the skin barrierfunction, but studies on xerosis have proven that moisturizers containing humectants...
surrounds cells in the stratum corneum and contributes to the skin's barrierfunction. Corneodesmosomes (modified desmosomes) facilitate cellular adhesion...
adhesion of adjacent keratinocytes and contributes to the skin barrier. A loss-of-function mutation of filaggrin causes loss of this lipid matrix and external...
lipids, and antimicrobial peptides contribute to maintain the important barrierfunction of the skin. Keratinocytes differentiate from epidermal stem cells...
inadequate capability of holding moisture as well as an imperfect lip barrierfunction. The Journal of the American Academy of Dermatology performed a study...
where δ(x) is the Dirac delta function. It is called a delta potential well if λ is negative, and a delta potential barrier if λ is positive. The delta...
Schottky barrier, named after Walter H. Schottky, is a potential energy barrier for electrons formed at a metal–semiconductor junction. Schottky barriers have...
similar to most roadside barriers, cable barriersfunction by capturing and/or redirecting the errant vehicle. Because these barriers are relatively inexpensive...
Schottky–Nordheim barrier of unreduced height equal to the local work-function φ, and f is the scaled barrier field for a Schottky–Nordheim barrier of unreduced...
renewal from lower epidermal layers and are essential for its function as a skin barrier. Corneocytes are keratinocytes without nuclei and cytoplasmic...
A vapor barrier (or vapour barrier) is any material used for damp proofing, typically a plastic or foil sheet, that resists diffusion of moisture through...