Search results for " propagation"

Engineered surface waves in hyperbolic metamaterials

2013

We analyzed surface-wave propagation that takes place at the boundary between a semi-infinite dielectric and a multilayered metamaterial, the latter with indefinite permittivity and cut normally to the layers. Known hyperbolization of the dispersion curve is discussed within distinct spectral regimes, including the role of the surrounding material. Hybridization of surface waves enable tighter confinement near the interface in comparison with pure-TM surface-plasmon polaritons. We demonstrate that the effective-medium approach deviates severely in practical implementations. By using the finite-element method, we predict the existence of long-range oblique surface waves. This research was fu…

Performance of an asymmetric and asynchronous decode-and-forward FBMC relay system

2014

End-to-end link performance of an asymmetric and asynchronous dual-hop decode-and-forward (DF) relay system built up using a causal multirate filter bank multicarrier (FBMC) technique operated under Rayleigh fading is presented. Three main performance measures namely bit error rate (BER), outage probability and channel capacity are used for this evaluation and approximate closed-form expressions for them are also made available. FBMC setup is modeled in exact form without any approximations while customizing to one of the most efficient subcarrier filter. Simulations are carried out in quasi-static multipath fading channels under symmetric, asymmetric, synchronous and asynchronous condition…

Improving statistical classification methods and ecological status assessment for river macroinvertebrates

2016

Aquatic ecosystems are facing a growing number of human-induced stressors and the need to implement more biomonitoring to assess the ecological status of water bodies is eminent. This dissertation aims at providing tools to reduce the costs and improve the accuracy of freshwater benthic macroinvertebrate biomonitoring. To improve the cost-e ciency, we consider automated classi cation and develop a novel classi er suitable for complex macroinvertebrate image data. To enhance the accuracy of macroinvertebrate biomonitoring, we study the statistical properties of the Percent Model A nity index crucial to current Finnish biomonitoring and the factors a ecting these statistics. Finally, we perfo…

Vasarzaļo rododendru spraudeņu pavairošanas potenciāls atkarībā no mātes augu un spraudeņu apstrādes

2015

Darba mērķis bija noskaidrot vasarzaļo rododendru spraudeņu pavairošanas potenciālu atkarībā no mātes augu priekšapstrādes (etiolācija, steidzināšana) un spraudeņu apstrādes ar auksīnu – indol-3-sviestskābi (ISS). Mātes augu etiolācija kopā ar ISS veicināja straujāku rizoģenēzi, bet neietekmēja apsakņoto spraudeņu skaitu. Etiolācija uzlaboja pārziemošanu grūtāk apsakņojamiem spraudeņiem. Mātes augu steidzināšana kopā ar ISS uzlaboja spraudeņu rizoģenēzi grūtāk apsakņojamiem genotipiem, veicināja jauno dzinumu attīstību, uzlabojot spraudeņu pārziemošanu. Nodrošinot apsakņotajiem spraudeņiem nepārtrauktu veģetācijas periodu, var būtiski palielināt pārziemojušo spraudeņu skaitu. Cietes koncent…

Comparing micro-cutting and mini-cutting technique for the clonal propagation of Metrosideros excelsa

2017

public gardens for its foliage and attractive red flowers. M. excelsa plants are commercially propagated by soft and semi-ripe cuttings. Therefore, new and more reliable propagation techniques derived both from conventional and advanced propagation methods should be considered to support Metrosideros nursery development. The mini-cutting and micro-cutting techniques were compared for the clonal propagation of M. excelsa. Ex vitro rooted micro-cuttings resulted superior to mini-cuttings in terms of rooting percentage, root number per cutting and root length by 23.5%, 42.5% and 2.4%, respectively. However, the mini-cutting technique can be considered an alternative reliable propagation method…

MR2954311 (Review) 35R30 35J05 76Nxx Elschner, J. (D-WIAS); Hsiao, G. C. [Hsiao, George C.] (1-DE); Rathsfeld, A. [Rathsfeld, Andreas] (D-WIAS) Recon…

2011

Analytical results for 2-D non-rectilinear waveguides based on a Green's function

2008

We consider the problem of wave propagation for a 2-D rectilinear optical waveguide which presents some perturbation. We construct a mathematical framework to study such a problem and prove the existence of a solution for the case of small imperfections. Our results are based on the knowledge of a Green's function for the rectilinear case.

The mechanically based non-local elasticity: an overview of main results and future challenges

2013

The mechanically based non-local elasticity has been used, recently, in wider and wider engineering applications involving small-size devices and/or materials with marked microstructures. The key feature of the model involves the presence of non-local effects as additional body forces acting on material masses and depending on their relative displacements. An overview of the main results of the theory is reported in this paper.