Sound source coding in the azimuthal plane: separating sounds via short-term interaural time difference estimations

The interaural time difference (ITD) is the main cue to perform sound localization for low-frequency sounds (below ~2kHz) in the azimuthal plane. The extractors for this cue are neurons of two nuclei of the mammalian auditory brainstem, the medial superior olive (MSO) and the low-frequency limb of the lateral superior olive (lLSO). The read-out mechanism on a population level is unknown as single neurons show different responses for frequency-varying stimuli. This poses a challenge especially for natural sound stimuli and complex auditory scenes which cover a wide range of frequencies, i.e., they have a very broad spectrum. To find an encoder of ITDs, we have developed so-called effective population models of the human MSO and lLSO. They are effective in the sense that the individual neurons are each identified by their three defining properties which determine their frequency-dependent ITD tuning: the best frequency (BF), the characteristic delay (CD) and the characteristic phase (CP). We have formulated an ITD decoding strategy in the 2d-space spanned by the membrane potentials of lLSO vs. MSO. From each hemisphere, a separate ITD can be decoded. These two estimations can be weighted and balanced accordingly to retrieve the location of sound sources in the horizontal plane. To this end, we make use of so-called short-term ITDs which are successive estimates in small time windows. Our results indicate that sound localization can be performed correctly in time windows as short as up to 1ms. To perform sound separation of stimuli within complex auditory scenes, we fit Gaussian Mixture Models to the short-term ITD estimate distributions. The results show that sound separation can be performed reliably when the long-term ITD estimation (which is a distribution of short-term ITDs) is made up of a time interval that is larger than 1s. Furthermore, we conclude that sounds can be separated and reconstructed from complex auditory scenes solely based on one auditory cue, the ITD

О возможности использования индуктивного параметрона для защиты от замыканий на землю в сетях с изолированной нейтралью

Показана возможность использования индуктивного параметрона как реагирующего органа в защитах от замыканий на землю в сетях с изолированной нейтралью. Защита с параметроном является селективной и равночувствительной, обладает достаточной чувствительностью

Multivariate kernel density estimation applied to sensitive geo-referenced administrative data protected via measurement error

Modern systems of official statistics require the timely estimation of area- specific densities of sub-populations. Ideally estimates should be based on precise geo-coded information, which is not available due to confidentiality constraints. One approach for ensuring confidentiality is by rounding the geo- coordinates. We propose multivariate non-parametric kernel density estimation that reverses the rounding process by using a Bayesian measurement error model. The methodology is applied to the Berlin register of residents for deriving density estimates of ethnic minorities and aged people. Estimates are used for identifying areas with a need for new advisory centres for migrants and infrastructure for older people

Carbon nanotube based sensors and fluctuation enhanced sensing

Trabajo presentado al 23rd International Conference on Amorphous and Nanocrystalline Semiconductors (ICANS 23)and E-MRS 2009 Spring Meeting, Symposium N – Carbon Nanotubes and Graphene.-- et al.Drop-cast thin films of multi-walled carbon nanotubes are used as gas sensors in a four-probe measurement setup. The novelty of the approach is that the sensor information is extracted from the noise of the dc resistance data using Fluctuation Enhanced Sensing (FES). We investigate the effects of measurement duration, gate voltage and frequency window on the chemical selectivity of the MWCNT-FES sensor. The selectivity of the device is superior to those of conventional gas sensors, and preliminary experiments indicate that it may also be possible to extract quantitative information from the noise.The financial support of the European Commission (FP6 STREP #17310 „SANES”), TEKES (projects: 52467 and 52468), Academy of Finland (projects: 120853, 128626 and 128908) and the Hungarian Scientific Research Fund (OTKA) through project NNF-78920 is acknowledged. YP and AR acknowledge funding by the Spanish MEC (FIS2007-65702-C02-01), "Grupos Consolidados UPV/EHU del Gobierno Vasco" (IT-319-07) and e-I3 ETSF project (Contract Number 211956). Computational resources for theoretical support are provided by the SGI/IZO-SGIker UPV/EHU (Arina cluster).). K.K. and G.T. thank the support (research fellow and researcher posts) received from the Academy of Finland. N.H. acknowledges the postgraduate student post received from the NGS-Nano.Peer reviewe

Implementation of Vibration Signals Receiving Unit on Raspberry Single-Board Computers

The paper dedicated to vibration measurement system development on the Raspberry Pi basis. Main features of the solution are low-cost, easy access to components and functionality and flexibility provided by Raspberry Pi usage. Circuit solution and configuring procedures are presented and described. In particular, block diagram of the vibration measurement system with piezo-electric sensors. Two variants of the vibration measurement system, on the Raspberry Pi B+ and Raspberry Pi 3B correspondingly, were implemented and tested as well. In addition, two variants of impedance-matching device were implemented. Conducted and described experiments confirm performance both separate components and the whole solution. Presented results are applicable for correlation leak detectors new algorithmic solutions and in educational process

Coupling of photoactive transition metal complexes to a functional polymer matrix**

Conductive polymers represent a promising alternative to semiconducting oxide electrodes typically used in dye-sensitized cathodes as they more easily allow a tuning of the physicochemical properties. This can then also be very beneficial for using them in light-driven catalysis. In this computational study, we address the coupling of Ru-based photosensitizers to a polymer matrix by combining two different first-principles electronic structure approaches. We use a periodic density functional theory code to properly account for the delocalized nature of the electronic states in the polymer. These ground state investigations are complemented by time-dependent density functional theory simulations to assess the Franck-Condon photophysics of the present photoactive hybrid material based on a molecular model system. Our results are consistent with recent experimental observations and allow to elucidate the light-driven redox chemical processes – eventually leading to charge separation – in the present functional hybrid systems with potential application as photocathode materials