Gaurav Sharma

Bio: Gaurav Sharma is an academic researcher from Shenzhen University. The author has contributed to research in topics: Medicine & Photocatalysis. The author has an hindex of 82, co-authored 1244 publications receiving 31482 citations. Previous affiliations of Gaurav Sharma include Northeastern University & D. E. Shaw & Co..

An Audio Watermark Designed for Efficient and Robust Resynchronization After Analog Playback

Abstract: We propose a spread spectrum (SS) audio watermark designed to withstand analog playback, including desynchronization caused by small differences between playback and recording rates. Desynchronization robustness relies on detecting short blocks of a magnitude-only watermark embedded in the frequency domain where the resolution of the SS chips can be reduced. Lost spreading gain due to the lower number of SS chips is compensated using blind dynamic time warping (DTW) detection (does not access original signal). DTW aligns sequences of blocks to improve robustness to interference while mitigating the vulnerabilities of long SS sequences to desynchronization. Results demonstrate that the proposed watermark survives analog playback and warping up to ±2%. Additionally, compared with a recent baseline scheme that uses brute force resampling to search for resynchronization, the proposed watermark is 300 times more computationally efficient, and does not compromise robustness to either desynchronization (e.g., jitter, resampling, time warping, frequency scaling) or non-desynchronizing modifications (e.g., AAC compression and additive noise).

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

SPAdes, a new genome assembly algorithm and its applications to single-cell sequencing ( 7th Annual SFAF Meeting, 2012)

Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.