Analysis of in-room mm-wave propagation: directional channel measurements and ray tracing simulations. - In: Journal of infrared, millimeter, and terahertz waves, ISSN 1866-6906, Bd. 38 (2017), 6, S. 727-744
https://doi.org/10.1007/s10762-017-0366-1
Current density reconstructions for Lorentz force evaluation. - In: Research in nondestructive evaluation, ISSN 1432-2110, Bd. 28 (2017), 2, S. 76-100
The detection and reconstruction of fatigue fractures is of great interest in quality assurance. In the framework of nondestructive testing, Lorentz force evaluation (LFE) is an evaluation technique to estimate flaws in electrically conductive materials based on measured Lorentz forces. In the forward solution for LFE, a defect can be interpreted as a distributed current source. This has motivated the authors to propose current density reconstructions (CDRs) calculated with minimum norm estimates to estimate defect geometries. The L1 and L2 norms tend to produce a solution which is either very focused or very smeared. To balance these constraints, the general Lp norm with 1 ≤ p ≤ 2 was used and the inverse solutions compared. This approach was applied to measured data obtained from a laminated composite and simulated data from a monolithic material. The results show that the L1.5 norm provides the most accurate inverse solutions. The location and extent of the defect are determined with an error of 15 % relative to the size of the defect. The depth estimation has a deviation of 50 %. It can be concluded that CDRs are a powerful method to reconstruct and characterize defects in LFE.
http://dx.doi.org/10.1080/09349847.2015.1111483
Model order selection and eigen similarity based framework for detection and identification of network attacks. - In: Journal of network and computer applications, ISSN 1095-8592, Bd. 90 (2017), S. 26-41
https://doi.org/10.1016/j.jnca.2017.04.012
Im Kampf gegen Landminen. - In: Forschung, ISSN 1522-2357, Bd. 42 (2017), 1, S. 20-23
https://doi.org/10.1002/fors.201790001
Design and analysis of compressive antenna arrays for direction of arrival estimation. - In: Signal processing, Bd. 138 (2017), S. 35-47
https://doi.org/10.1016/j.sigpro.2017.03.013
Performance analysis of multi-dimensional ESPRIT-type algorithms for arbitrary and strictly non-circular sources with spatial smoothing. - In: IEEE transactions on signal processing, ISSN 1941-0476, Bd. 65 (2017), 9, S. 2262-2276
https://doi.org/10.1109/TSP.2017.2652388
Tensor-based methods for blind spatial signature estimation in multidimensional sensor arrays. - In: International journal of antennas and propagation, ISSN 1687-5877, Bd. 2017 (2017), Article ID 1615962, insges. 11 S.
https://doi.org/10.1155/2017/1615962
Low complexity performance assessment of a sensor array via unscented transformation. - In: Digital signal processing, ISSN 1051-2004, Bd. 63 (2017), S. 190-198
http://dx.doi.org/10.1016/j.dsp.2017.01.007
Computation of Lorentz force and 3-D eddy current distribution in translatory moving conductors in the field of a permanent magnet. - In: IEEE transactions on magnetics, ISSN 1941-0069, Bd. 53 (2017), 2, S. 7000109, insges. 9 S.
Determination of the 3-D eddy current distribution inside a translatory moving conductor under a permanent magnet can accurately be done by using finite-element method (FEM). However, FEM calculations are very expensive, as they require discretization of the whole conductor volume. In this paper, we propose a new technique, to be called boundary element source method (BESM), where only boundary layers are discretized. The BESM is a modification of the hybrid boundary element method (HBEM). In the BESM, the concentrated point sources placed at the centers of boundary elements for the HBEM are replaced by distributed charge density over the area of the boundary element. This is especially useful in the regions, where neighboring boundary meshes significantly affect one another and when calculation point of eddy current is very close or belong to the surface of a boundary element. The method can handle arbitrary geometries of the specimen as well as the defect and arbitrary orientation of the magnetization vector. The accuracy of the proposed method is verified by comparing the results with the solutions obtained from a finite-element model. The proposed BESM approach is shown to be simple, robust, and computationally accurate.
https://doi.org/10.1109/TMAG.2016.2622223
ESPRIT-Hilbert-based audio tampering detection with SVM classifier for forensic analysis via electrical network frequency. - In: IEEE transactions on information forensics and security, ISSN 1556-6021, Bd. 12 (2017), 4, S. 853-864
https://doi.org/10.1109/TIFS.2016.2636095