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Application of CRAFT (complete reduction to amplitude frequency table) in nonuniformly sampled (NUS) 2d NMR data processing

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MAGNETIC RESONANCE IN CHEMISTRY 2018年第6期56卷 535-545页

作者： Krishnamurthy, Krish Hari, Natarajan Chempacker LLC San Jose CA 95135 USA SASTRA Univ Sch Chem & Biotechnol NMR Lab Thanjavur India

The recently published CRAFT (complete reduction to amplitude frequency table) technique converts the raw FId data (i.e., time domain data) into a table of frequencies, amplitudes, decay rate constants, and phases. It offers an alternate approach to decimate time-domain data, with minimal preprocessing step. It has been shown that application of CRAFT technique to process the t(1) dimension of the 2d data significantly improved the detectable resolution by its ability to analyze without the use of ubiquitous apodization of extensively zero-filled data. It was noted earlier that CRAFT did not resolve sinusoids that were not already resolvable in time-domain (i.e., t(1)max dependent resolution). We present a combined NUS-IST-CRAFT approach wherein the NUS acquisition technique (sparse sampling technique) increases the intrinsic resolution in time-domain (by increasing t(1)max), IST fills the gap in the sparse sampling, and CRAFT processing extracts the information without loss due to any severe apodization. NUS and CRAFT are thus complementary techniques to improve intrinsic and usable resolution. We show that significant improvement can be achieved with this combination over conventional NUS-IST processing. With reasonable sensitivity, the models can be extended to significantly higher t(1)max to generate an indirect-dEPT spectrum that rivals the direct observe counterpart.

关键词： 2d processing Bayesian time-domain analysis CRAFT Nonuniform sampling Iterative Soft Threshold

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Unrolling Post-Mortem 3d Fingerprints Using Mosaicking Pressure Simulation Technique

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IEEE ACCESS 2019年 7卷 88174-88185页

作者： Panetta, Karen Rajeev, Srijith Kamath, K. M. Shreyas Agaian, Sos S. Tufts Univ Dept Elect & Comp Engn Medford MA 02155 USA CUNY Dept Comp Sci New York NY 10016 USA

Post-mortem fingerprints are a valuable biometric used to aid in the identification of a deceased individual. However, fingerprints from the deceased undergo decomposition leading to indefinite structure when compared to ante-mortem fingerprints. Moreover, the performance of the existing two-dimensional (2d) fingerprint recognition systems is still below the expected potential. These problems arise because fingerprints are generally captured by manipulating a finger against a plane. In post-mortem fingerprint recovery, the decedent's finger must go through several reconditioning processes to prevent the rapid onslaught of decomposition. To address these deficiencies associated with the 2d systems, three-dimensional (3d) scanning systems have been employed to capture fingerprints. The 3d technology is still in its transient phase and is limited primarily by 1) the lack of existing 3d databases;2) the deficiency of 3d-to-2d fingerprint image mapping algorithms, 3) the incapacity to model and recreate the 2d fingerprint capturing procedure to improve 3d-2d fingerprint verification;and 4) the inability to apply traditional fingerprint unrolling techniques on post-mortem 3d fingerprints. This paper presents a novel method to perform postmortem 3d fingerprint unrolling and pressure simulation to produce fingerprint images that are compatible with 2d fingerprint recognition systems. The thrust of this paper strives to: 1) develop a correspondence between 3d touchless and contact-based 2d fingerprint images;2) model fingerprints with deformities to provide a viable fingerprint image for matching and;3) develop a mosaic pressure simulation (MPS) algorithm to recreate the effects of 2d fingerprint capturing procedure.

关键词： 2d processing 3d processing ante-mortem authentication biometric fingerprint forensics image-stitching modeling post-mortem pressure-simulation processing recognition unraveling unrolling verification

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Application of CRAFT in two-dimensional NMR data processing

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MAGNETIC RESONANCE IN CHEMISTRY 2017年第3期55卷 224-232页

作者： Krishnamurthy, Krish Sefler, Andrea M. Russell, david J. Chempacker LLC San Jose CA 95135 USA Sci Consulting Cary NC USA Genentech Inc Small Mol Analyt Chem & QC San Francisco CA USA

Two-dimensional (2d) data are typically truncated in both dimensions, but invariably and severely so in the indirect dimension. These truncated FIds and/or interferograms are extensively zero filled, and Fourier transformation of such zero-filled data is always preceded by a rapidly decaying apodization function. Hence, the frequency line width in the spectrum (at least parallel to the evolution dimension) is almost always dominated by the apodization function. Such apodization-driven line broadening in the indirect (t(1)) dimension leads to the lack of clear resolution of cross peaks in the 2d spectrum. Time-domain analysis (i.e. extraction of frequency, amplitudes, line width, and phase parameters directly from the FId, in this case via Bayesian modeling into a tabular format) of NMR data is another approach for spectral resonance characterization and quantification. The recently published complete reduction to amplitude frequency table (CRAFT) technique converts the raw FId data (i.e. time-domain data) into a table of frequencies, amplitudes, decay rate constants, and phases. CRAFT analyses of time-domain data require minimal or no apodization prior to extraction of the four parameters. We used the CRAFT processing approach for the decimation of the interferograms and compared the results from a variety of 2d spectra against conventional processing with and without linear prediction. The results show that use of the CRAFT technique to decimate the t(1) interferograms yields much narrower spectral line width of the resonances, circumventing the loss of resolution due to apodization. Copyright (C) 2016 John Wiley & Sons, Ltd.

关键词： 2d processing Bayesian time-domain analysis CRAFT apodization linear prediction 2d resolution 2d linewidth

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Real-time ultra-low delay audio coding for wireless transmission

Real-time ultra-low delay audio coding for wireless transmis...

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2005 The 2nd IEE/EURASIP Conference on dSPenabledRadio (Ref. No. 2005/11086)

作者： G.Y. Luo Buckinghamshire Chilterns University College UK

ISBN: (纸本)0863415601

Encoding and decoding delays have become increasingly critical in real-time audio wireless applications. In order to maximize compression and minimize coding delays, this paper presents a two dimensional (2d) fast lifting wavelet technique with boundary effects minimized for very short block processing to achieve ultra low delay for wireless transmission. The 2d spatial-frequency processing of audio input signal fully exploits the correlation for better compression performance. A modified 2d embedded SPIHT (set partitioning in hierarchical trees) algorithm with more bits used to encode the wavelet coefficients and transmitting fewer bits in the sorting pass, is implemented to reduce the correlation between the coefficients at different decomposition levels and inside each band at scalable bit rates. The embedded coding offers the error resilience feature that is evaluated using a simulated transmission channel with random errors. In the face of transmission errors, joint source-channel SPIHT coding scheme for unequal error protection thus can be easily designed by varying both source coding bit rate and channel coding redundancy with added complexity and delay depending on the channel error degree. Experimental tests demonstrate that the proposed coder is efficient and has low complexity with less memory requirements in implementation.

关键词： Wireless transmission Audio compression 2d processing Embedded coding Error Resilience WIRELESS TRANSMISSION error-resilience embedded encoding Audio compression Audio Bit rate coding memory requirements error protection delay Transmission channels

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