Electronic commerce is undergoing significant advances that make online purchases difficult to manage due transaction complexity. The fact e-commerce a complex set of interrelated and interconnected transactions does not exclude risks. Basing on literature review 106 publications, this article identifies, analyzes discusses the risks threatening e-commerce. This allowed us identify four major r...

In conventional analog filters operated in class-A mode, bias currents are large enough to accommodate the largest expected peak input signal. When only a small input signal (including in-band and out-of-band components) is present, these large bias currents unnecessarily waste power and create noise. A more optimal situation results if bias currents can be dynamically set by the system, depend...

Blotches are common artifacts in old film sequences that manifest themselves as disturbing bright or dark spots. Existing methods for detecting blotches can achieve high detection rates. High detection rates are only useful if the corresponding number of false alarms is not too high, visible artifacts in the corrected sequence result otherwise. We show that the performance of blotch detectors c...

Recent investigations in humans point out to a disturbing effect of auditory stimuli on the functional integrity of the brain-gut axis. The study was devoted to a systematic comparative evaluation of the effect of noises of different frequency spectra on the postprandial electrical and transport functions of the digestive tract in humans. Twenty six healthy subjects attended a cross-over study,...

In many situations of digital speech communication (e.g. hands-free telephony or electronic hearing aids) the speech signal picked up by the microphone is disturbed by acoustic background noise. Therefore, adaptive ltering techniques which aim at the reduction of the disturbing noise are subject of current research activities (e.g. [1]). Although some of the already known adaptive techniques { ...

The voltage source used for testing electrical equipment has to achieve special requirements, which are noted in the international standards. Still today the test voltages for routineand type tests of utilities for the power engineering are generated by motor-generator sets. Attempting to replace the m.-g. sets with static frequency converters, two major problems occur in implementing this tech...

A previously devised approach for the reconstruction of Langevin processes from given data is revised with respect to disturbances stemming from finite sampling rates and the presence of external measurement noise. For these two cases and a combination of both three different estimates for the drift and diffusion functions are introduced, and an optimization procedure is presented that allows t...

Measurements in quantum mechanics cannot perfectly distinguish all states and necessarily disturb the measured system. We present and analyse a proposal to demonstrate fundamental limits on quantum control of a single qubit arising from these properties of quantum measurements. We consider a qubit prepared in one of two non-orthogonal states and subsequently subjected to dephasing noise. The ta...

Peak signal-to-noise ratio (PSNR) is not a good measure of perceived picture quality, especially at low bit rates of coding. This paper proposes a new approach for computing perceptual distortion for visual signal in order to provide an objective measure for perceptual quality at low bit rate coding in typically mobile communications. The regions with three major perceptually disturbing artefac...