Hierarchical B-picture mode decision in H.264/SVC

To enable robust video transmission over heterogeneous networks, the hierarchical B-picture prediction structure is employed in the state-of-the-art video coding standard H.264/SVC, aiming to produce scalable bitstreams with various frame rates. However, the exhaustive mode decision process with the hierarchical B-picture structure increases the computational complexity of H.264/SVC encoding dramatically. In this paper, a fast mode decision algorithm is proposed to speed up H.264/SVC encoding with the hierarchical B-picture structure, which is achieved by utilizing macroblock (MB) features, correlation of temporal–spatial neighboring MBs, and the discrepant characteristics of hierarchical layers. Extensive experimental results demonstrate that the proposed algorithm is able to reduce the encoding time of H.264/SVC significantly for video sequences with a wide range of resolutions, and meanwhile the video quality and compression ratio are well preserved.     

Multiview deblurring for 3-D images from light-sheet-based fluorescence microscopy

We propose an algorithm for 3-D multiview deblurring using spatially variant point spread functions (PSFs). The algorithm is applied to multiview reconstruction of volumetric microscopy images. It includes registration and estimation of the PSFs using irregularly placed point markers (beads). We formulate multiview deblurring as an energy minimization problem subject to L1-regularization. Optimization is based on the regularized Lucy-Richardson algorithm, which we extend to deal with our more general model. The model parameters are chosen in a profound way by optimizing them on a realistic training set. We quantitatively and qualitatively compare with existing methods and show that our method provides better signal-to-noise ratio and increases the resolution of the reconstructed images.     

Finding Quadratic Schedules for Affine Recurrence Equations Via Nonsmooth Optimization

Frequently, affine recurrence equations can be scheduled more efficiently by quadratic scheduling functions than by linear scheduling functions. In this paper, the problem of finding optimal quadratic schedules for affine recurrence equations is formulated as a convex nonsmooth programming problem. In particular, sufficient constraints for causality are used generalizing Lamport's condition. In this way, the presented problem formulation becomes independent of the problem size. The research tool AQUAD is described implementing this problem formulation. Several nontrivial examples demonstrate that AQUAD can be effectively used to calculate quadratic schedules for affine recurrence equations. Finally, it is shown how array processors can be synthesized from affine recurrence equations which are scheduled by quadratic functions with a singular Hessian matrix.     

Multifunktionales Batteriespeichersystem

In the national research project “Multifunctional Battery Storage System (MBS)” open questions were answered concerning the technical feasibility and profitability of a grid-connected battery storage system using a vanadium-redox-flow battery in combination with the renewable power generation plants PV and small wind power (Sterrer et al., Multifunktionales Batteriespeichersystem—MBS-Endbericht. Industrielle Forschung im Rahmen der österreichischen Programmlinie Neue Energie 2020, 3. Ausschreibung, noch nicht veröffentlicht, 2013). The technical implementation and the demonstration operation of the pilot plant over a period of two years showed that the battery storage system is suitable for intelligent marketing of renewable energy as well as the provision of system services for grid stabilisation. However, the investigation of different operating strategies of the pilot battery-storage system, a large scale storage system and pooled PV/battery storage systems as virtual power plant for the participation at the energy trading market and energy reserve market showed that all operation strategies being considered in this study may not be profitable in foreseeable future. However, if the costs of the battery storage system can be reduced to about 250 €/kWh until the year 2030, the application of the vanadium-redox-flow battery in particular in large-scale storage plants (e.g. 10 MW, 100 MWh) for the participation at the energy reserve market seems realistic.     

Do ESD fails in systems correlate with IC ESD robustness?

Integrated circuits (ICs) are qualified for their electrostatic discharge (ESD) robustness according to the well-known IC ESD standards Human Body Model, Machine Model, and Charged Device Model in order to guarantee safe handling in ESD protected areas. For electronic systems like mobile phones which are in direct use by consumers, certain robustness against system level ESD is demanded, too. As the ESD test methods of device and system level stress are completely different (waveforms, stress application, operating condition of the DUT, etc.), correlations between models of both worlds are difficult to establish. Therefore, the system vendors more and more demand a specified ESD robustness for devices (ICs) according to an ESD system level standard. Testing ICs to a system level ESD standard requires careful considerations; first ideas are summarized in the new Standard Practice “Human Metal Model” of the ESDA/ANSI. However, the approach of deriving system ESD robustness from IC robustness is currently too much simplified and bears severe potential risks. Nevertheless, there are methodologies and approaches to use IC ESD characterization for defining ESD protection concepts for systems. Appropriate high-current characterization of ICs can be the cornerstone for a successfully optimized system ESD protection.     

Charge transfer in thin films of donor–acceptor complexes studied by infrared spectroscopy

The degree of charge transfer in thin films of organic charge transfer (CT)-complexes, which are deposited via thermal evaporation, is examined via infrared-spectroscopy. We demonstrate a linear relationship between the shift in the excitation energy of the CN-stretching mode of CT-complexes with the acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ) and the charge transfer. The measured correlation corresponds very well with DFT calculations. For Na-TCNQ we observe a splitting in the peak of the CN-stretching mode, which can be explained by the coupling of two modes and was confirmed by the calculations. In CT-complexes with partial charge transfer the appearance of an electronic excitation is demonstrated.     

Merocyanine/C60 Planar Heterojunction Solar Cells: Effect of Dye Orientation on Exciton Dissociation and Solar Cell Performance

In this study the charge dissociation at the donor/acceptor heterointerface of thermally evaporated planar heterojunction merocyanine/C₆₀ organic solar cells is investigated. Deposition of the donor material on a heated substrate as well as post‐annealing of the complete devices at temperatures above the glass transition temperature of the donor material results in a twofold increase of the fill factor. An analytical model employing an electric‐field‐dependent exciton dissociation mechanism reveals that geminate recombination is limiting the performance of as‐deposited cells. Fourier‐transform infrared ellipsometry shows that, at temperatures above the glass transition temperature of the donor material, the orientation of the dye molecules in the donor films undergoes changes upon annealing. Based on this finding, the influence of the dye molecules’ orientations on the charge‐transfer state energies is calculated by quantum mechanical/molecular mechanics methods. The results of these detailed studies provide new insight into the exciton dissociation process in organic photovoltaic devices, and thus valuable guidelines for designing new donor materials.     

Fiber Bragg Gratings in Small-Core Ge-Doped Photonic Crystal Fibers

This paper reports fiber Bragg gratings （FBGs） inscribed in a small-core Ge-doped photonic crystal fibers with a UV laser and a Talbot interferometer. The responses of such FBGs to temper- ature, strain, bending, and transverse-loading were systematically investigated. The Bragg wavelength of the FBGs shifts toward longer wavelengths with increasing temperature, tensile strain, and transverse-loading. The bending and transverse- loading properties of the FBGs are sensitive to the fiber orientations.     

SCR operation mode of diode strings for ESD protection

Diodes and diode strings in 90 nm and beyond technologies are investigated by measurement and device simulation. After a thorough calibration, the device simulator is utilised to achieve a better understanding and an enhanced device performance of diode strings under static and transient ESD conditions. Thereto, parasitic transistors and a so far neglected parasitic thyristor (SCR) in the diode string are regarded, exploited and optimised.