The paper describes solutions, how to improve a quality of basic testing methods to be possible to use them for dynamic testing high-resolution / middle speed AD converters and AD modules. The following methods are described: an application of low-distortion band pass filters, a digital correction of a known distortion of a testing signal, an application of a two-tone (or multitone) signal, an ...

BACKGROUND Quantification of myocardial blood flow requires knowledge of the amount of contrast agent in the myocardial tissue and the arterial input function (AIF) driving the delivery of this contrast agent. Accurate quantification is challenged by the lack of linearity between the measured signal and contrast agent concentration. This work characterizes sources of non-linearity and presents ...

We consider the optical fiber channel modeled by the nonlinear Schrödinger equation with zero dispersion and additive Gaussian noise. Using the Feynman path-integral approach for the model, we find corrections to conditional probability density function, output signal distribution, conditional and output signal entropies, and the channel capacity at large signal-to-noise ratio. We demonstrate t...

We introduce a method that allows analytical or semianalytical estimating of the post-error correction bit error rate (BER) when a forward-error correction is utilized for transmitting information through a noisy channel. The generic method that applies to a variety of error-correction schemes in the regimes where the BER is low is illustrated using the example of a finite-size code approximate...

OBJECTIVE To evaluate the clinical application of phased-array surface coil intensity correction in magnetic resonance imaging (MRI) in spinal metastases. METHODS 3 phantoms and 50 patients with a corresponding total number of 80 spinal metastases were included in this study. Fast spin echo T1- and T2- weighted MRI with and without surface coil intensity correction was routinely performed for...

This work describes a new method for the correction of signal drift of a MS-based sensor by standard gas addition (SGA). It consists of introducing a gaseous He-Xe mixture continuously and independently of the carrier gas into the mass spectrometer source. To mimic the disturbances generated by periodical tuning of the mass detector, three series of adjustments were made to the main acquisition...

Magnetic resonance imaging (MRI) is highly susceptible to subject’s motion and can significantly degrade image quality. In brain MRI exams, involuntary headmovements can affect the sampled k-space data. Such unintended alterations may result in visible image artifacts such as blurring, ghosting and others, and therefore potentially disqualify the image fromdiagnostic purposes. Methods to charac...

PURPOSE Image non-uniformity may cause substantial problems in magnetic resonance (MR) imaging especially when a 3-T scanner is used. We evaluated the effect of image non-uniformity correction in gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging using a 3-T scanner. METHODS Two commercially available methods for image non-uniformity correction, surf...

A new charge loss correction method using genetic algorithms (GA) has been proposed to improve gamma ray energy spectrum characteristics of CdZnTe detectors. The correction method is based on the analysis of signal waveform shapes. GA recognizes the charge generation places for each signal and provides the related corrective factors of the pulse heights; the corrected energy spectrum was obtain...

A method to increase the Signal—to—Noise Ratio (SNR) of speech codecs is presented. It has been applied to Adaptive Delta Modulation (ADM) according to Jayant's algorithm. Observations indicate that bit streams resulting from these coders and quantization errors are correlated to some extend. Based on this experience a Quantization Error Correction method (QEC) has been developed that improves ...