Time–frequency analysis of tribological systems—part II: tribology of head–disk interactions

Head–disk interface processes operating in contact and near contact recording generate signals that have a distinct frequency for short time intervals and these processes are known as non-stationary. Time–frequency representation displays time, frequency, and amplitude to characterize such processes. Examples drawn from practical head–disk interface signals are analyzed by adapting the fast Fourier transform algorithm to illustrate the dynamic features jointly in time and frequency. Time–frequency analysis of laser Doppler vibrometer (LDV), friction, and acoustic emission (AE) signals give evidence of non-stationary signals obtained from head–disk dynamics experiments. Novel results depicted by the time–frequency analysis technique not reported elsewhere demonstrate the benefit and usefulness of the proposed techniques.     

Designing a camera placement assistance system for human motion capture based on a guided genetic algorithm

Virtual Reality - In multi-camera motion capture systems, determining the optimal camera configuration (camera positions and orientations) is still an unresolved problem. At present, configurations...     

QRS complex detection using Empirical Mode Decomposition

In this paper, we present a new Empirical Mode Decomposition based algorithm for the purpose of QRS complex detection. This algorithm requires the following stages: a high-pass filter, signal Empirical Mode Decomposition, a nonlinear transform, an integration and finally, a low-pass filter is used. In order to evaluate the proposed technique, the well known ECG MIT–BIH database has been used. Moreover it is compared to a reference technique, namely “Christov's” detection method. As it will be shown later, the proposed algorithm allows to achieve high detection performances, described by means both the sensitivity and the specificity parameters.     

Time–frequency analysis of tribological systems—part I: implementation and interpretation

A novel technique adapting the time–frequency analysis has been utilized to characterize stationary and non-stationary signals from tribological interactions. This representation displays time, frequency, and signal magnitude to decipher signals emanating from such interactions. Short-time Fourier transform, Wigner, Coi–Williams, and Zhao–Atlas–Marks distributions are suited to represent stationary and non-stationary signals. Some of the most complex tribological phenomena involve head–disk interactions in magnetic recording systems. Examples drawn from practical head–disk interface tests are analyzed by using the fast Fourier transform algorithm to illustrate the dynamic features of various distributions. Time–frequency representation of output spectrums of laser doppler vibrometer (LDV), strain gage sensor, and acoustic emission (AE) sensor obtained from head–disk experiments giving evidence of stationary and non-stationary behavior are investigated.     

Identification and Characterization of an Exonic Duplication in PALB2 in a Man with Synchronous Breast and Prostate Cancer

PALB2 (partner and localizer of BRCA2), as indicated by its name, is a BRCA2-interacting protein that plays an important role in homologous recombination (HR) and DNA double-strand break (DSB) repair. While pathogenic variants of PALB2 have been well proven to confer an increased risk of breast cancer, data on its involvement in prostate cancer (PrC) have not been clearly demonstrated. We investigated, using targeted next generation sequencing (NGS), a 59-year-old Caucasian man who developed synchronous breast and prostate cancers. This genetic investigation allowed to identify an intragenic germline heterozygous duplication in PALB2, implicating intronic repetitive sequences spanning exon 11. This variant was confirmed by multiplex ligation probe amplification (MLPA), and genomic breakpoints have been identified and characterized at the nucleotide level (c.3114-811_3202-1756dup) using an approach based on walking PCR, long range PCR, and Sanger sequencing. RT-PCR using mRNA extracted from lymphocytes and followed by Sanger sequencing revealed a tandem duplication r.3114_3201dup; p.(Gly1068Glufs * 14). This duplication results in the synthesis of a truncated, and most-likely, non-functional protein. These findings expand the phenotypic spectrum of PALB2 variants and may improve the yield of genetic diagnoses in this field.