43 research outputs found
Smolyak's algorithm: A powerful black box for the acceleration of scientific computations
We provide a general discussion of Smolyak's algorithm for the acceleration
of scientific computations. The algorithm first appeared in Smolyak's work on
multidimensional integration and interpolation. Since then, it has been
generalized in multiple directions and has been associated with the keywords:
sparse grids, hyperbolic cross approximation, combination technique, and
multilevel methods. Variants of Smolyak's algorithm have been employed in the
computation of high-dimensional integrals in finance, chemistry, and physics,
in the numerical solution of partial and stochastic differential equations, and
in uncertainty quantification. Motivated by this broad and ever-increasing
range of applications, we describe a general framework that summarizes
fundamental results and assumptions in a concise application-independent
manner
Hot new directions for quasi-Monte Carlo research in step with applications
This article provides an overview of some interfaces between the theory of
quasi-Monte Carlo (QMC) methods and applications. We summarize three QMC
theoretical settings: first order QMC methods in the unit cube and in
, and higher order QMC methods in the unit cube. One important
feature is that their error bounds can be independent of the dimension
under appropriate conditions on the function spaces. Another important feature
is that good parameters for these QMC methods can be obtained by fast efficient
algorithms even when is large. We outline three different applications and
explain how they can tap into the different QMC theory. We also discuss three
cost saving strategies that can be combined with QMC in these applications.
Many of these recent QMC theory and methods are developed not in isolation, but
in close connection with applications
The applicability of genetically modified microorganisms in bioremediation of contaminated environments
Inżynieria genetyczna, będąca nowoczesną technologią, pozwala na projektowanie mikroorganizmów zdolnych do rozkładu określonego typu zanieczyszczeń. Konstruowanie GMMs na potrzeby bioremediacji jest możliwe dzięki poznaniu mechanizmów degradacji związków toksycznych, szlaków metabolicznych, enzymów katabolicznych oraz odpowiednich genów. Do detekcji i wizualizacji GMMs w środowisku służą różne metody molekularne: FISH, in situ PCR, DGGE, TGGE, T-RFLP, ARDRA oraz markery selekcyjne (lux, gfp, lacZ, xylE). W celu zminimalizowania ryzyka wynikającego z uwolnienia GMMs do środowiska stosowane są pewne bariery genetyczne. Mają one na celu ograniczenie przeżywalności rekombinantów oraz transferu genów do mikroorganizmów autochtonicznych. W artykule omówiono zasady projektowania GMMs oraz przedstawiono przykłady ich praktycznego wykorzystania w bioremediacji zanieczyszczonych środowisk.Genetic engineering is a modern technology, which Allowi to design microorganisms capable of degrading specific contaminants. The construction of GMMs for bioremediation purposes is possible because many degradative pathways, enzyme and their respective genes are known and biochemical reactions are well understood. For selection and identification of GMMs in the environment many molecular techniques were developed. They include FISH, in situ PCR, DGGE, TGGE, T-RFLP, ARDRA and marker genes (lux, gfp, lacZ, xylE). In order to reduce potential risk of the use of GMMs in the environment some genetic barriers were created. They limit survival of the recombinants and gene transfer into autochthonous microorganisms. In this review the construction and practical applications of GMMs in bioremediation studies are discussed