Article
Refine
Year of publication
Institute
- Fachbereich Medizintechnik und Technomathematik (1316)
- INB - Institut für Nano- und Biotechnologien (485)
- Fachbereich Chemie und Biotechnologie (460)
- Fachbereich Elektrotechnik und Informationstechnik (413)
- IfB - Institut für Bioengineering (392)
- Fachbereich Energietechnik (355)
- Fachbereich Luft- und Raumfahrttechnik (243)
- Fachbereich Maschinenbau und Mechatronik (147)
- Fachbereich Wirtschaftswissenschaften (114)
- Fachbereich Bauingenieurwesen (65)
Has Fulltext
- no (3205) (remove)
Language
- English (3205) (remove)
Document Type
- Article (3205) (remove)
Keywords
- avalanche (5)
- Earthquake (4)
- LAPS (4)
- field-effect sensor (4)
- frequency mixing magnetic detection (4)
- CellDrum (3)
- Heparin (3)
- additive manufacturing (3)
- capacitive field-effect sensor (3)
- hydrogen peroxide (3)
At the present time, one of the most serious environmental problems of Central Asia and South Kazakhstan is the ongoing large-scale deterioration of principal urban tree populations. Several major centers of massive spread of invasive plant pests have been found in urban dendroflora of this region. The degree of damage of seven most wide-spread aboriginal tree species was found to range from 21.4±1.1 to 85.4±1.8%. In particular, the integrity of the native communities of sycamore (Platanus spp.), willow (Salix spp.), poplar (Populus spp.) and elm (Ulmus spp.) is highly endangered. Our taxonomic analysis of the most dangerous tree pests of the region has revealed them as neobiontic xylophilous insects such as Cossus cossus L. (Order: Lepidoptera L.) Monochamus urussovi Fisch., Monochamus sutor L., Acanthocinus aedelis L. and Ñetonia aureate L. (Order: Coleoptera L.). We relate the origin of this threatening trend with the import of industrial wood in the mid 90s of the last century that was associated with high degree of the constructional work in the region. Because of the absence of efficient natural predators of the pest species, the application of microbiological methods of the pest control and limitation is suggested.
There is a very large number of very important situations which can be modeled with nonlinear parabolic partial differential equations (PDEs) in several dimensions. In general, these PDEs can be solved by discretizing in the spatial variables and transforming them into huge systems of ordinary differential equations (ODEs), which are very stiff. Therefore, standard explicit methods require a large number of iterations to solve stiff problems. But implicit schemes are computationally very expensive when solving huge systems of nonlinear ODEs. Several families of Extrapolated Stabilized Explicit Runge-Kutta schemes (ESERK) with different order of accuracy (3 to 6) are derived and analyzed in this work. They are explicit methods, with stability regions extended, along the negative real semi-axis, quadratically with respect to the number of stages s, hence they can be considered to solve stiff problems much faster than traditional explicit schemes. Additionally, they allow the adaptation of the step length easily with a very small cost.
Two new families of ESERK schemes (ESERK3 and ESERK6) are derived, and analyzed, in this work. Each family has more than 50 new schemes, with up to 84.000 stages in the case of ESERK6. For the first time, we also parallelized all these new variable step length and variable number of stages algorithms (ESERK3, ESERK4, ESERK5, and ESERK6). These parallelized strategies allow to decrease times significantly, as it is discussed and also shown numerically in two problems. Thus, the new codes provide very good results compared to other well-known ODE solvers. Finally, a new strategy is proposed to increase the efficiency of these schemes, and it is discussed the idea of combining ESERK families in one code, because typically, stiff problems have different zones and according to them and the requested tolerance the optimum order of convergence is different.
Solution of plane anisotropic elastostatical boundary value problems by singular integral equations
(1982)