The unsupervised learning of spectro-temporal speech patterns is relevant in a broad range of tasks. Convolutive non-negative matrix factorization (CNMF) and its sparse version, convolutive non-negative sparse coding (CNSC), are powerful, related tools. A particular difficulty of CNMF/CNSC, however, is the high demand on computing power and memory, which can prohibit their application to large ...

There are various ways to impose a potential variation in time, and subsequently a series of voltammetric methods. Cyclic voltammetry relies on linearly scanning the potential in time, observing a triangular waveform variation [1-3]. Differential pulse voltammetry is based on two samplings of the current intensity for each potential pulse: one measurement before applying the pulse, and the seco...

We deal with blind signal extraction in the framework of a convolutive mixture of independent sources. Considering so-called reference signals, we generalize former identifiability conditions. Based on this result, we propose to incorporate some a priori information in the references. We show the validity of reference based contrast functions in two semi-blind situations. The results are confir...

In this study, the protocol for arsenic (III) detection from an aqueous solution using stripping voltammetry on a silver-modified synthetic zeolite-carbonnanotubes-epoxy composite electrode (CNT-AgSZ) was elaborated. Three types of electrochemical techniques were used in order to optimize the operating conditions, i.e., cyclic voltammetry, differential-pulsed voltammetry and squarewave voltamme...

In this work, a simple and sensitive electrochemical method was developed to determine Sudan I by cyclic voltammetry and differential pulse voltammetry using a glassy carbon electrode modified with a chitosan/carbon nanotube composite. In cyclic voltammetry, Sudan I exhibited a well-defined oxidation peak located at 0.72 V at the multi-walled carbon nanotube (MWCNT)/chitosan-modified GCE. The d...

The voltammetric performance of edge-plane pyrolytic graphite (EPG) electrode via adsorptive stripping voltammetry was investigated for study of the electrochemical behavior of omeprazole (OMZ) in aqueous solution. The results revealed that the oxidation of OMZ is an irreversible pH-dependent process that proceeds with the transfer of one electron and one proton in an adsorption-controlled mech...

While dopamine input to the dorsal striatum is well-known to be critical for action selection, including alcohol-motivated behaviors, it is unknown whether changes in phasic dopamine accompany these behaviors. Long-term alcohol abuse is believed to promote alterations in the neurocircuitry of reward learning in both ventral and dorsal striatum, potentially through increasing dopamine release. U...

This thesis addresses the problem of the optimal inversion of a linear acoustical convolutive mixing process by means of multichannel linear filtering. In most real-world acoustical scenarios, a number of sound emitting sources are encountered, which may be simultaneously active. When perceiving the sound of these sources by direct listening or from microphone recordings, the original undistort...