The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Yan Hong - One of the best experts on this subject based on the ideXlab platform.
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normal inverse bimodule operation Hadamard Transform ion mobility spectrometry
Analytica Chimica Acta, 2018Co-Authors: Yan Hong, Chaoqun Huang, Sheng Liu, Lei Xia, Chengyin Shen, Yannan ChuAbstract:In order to suppress or eliminate the spurious peaks and improve signal-to-noise ratio (SNR) of Hadamard Transform ion mobility spectrometry (HT-IMS), a normal-inverse bimodule operation Hadamard Transform - ion mobility spectrometry (NIBOHT-IMS) technique was developed. In this novel technique, a normal and inverse pseudo random binary sequence (PRBS) was produced in sequential order by an ion gate controller and utilized to control the ion gate of IMS, and then the normal HT-IMS mobility spectrum and the inverse HT-IMS mobility spectrum were obtained. A NIBOHT-IMS mobility spectrum was gained by subtracting the inverse HT-IMS mobility spectrum from normal HT-IMS mobility spectrum. Experimental results demonstrate that the NIBOHT-IMS technique can significantly suppress or eliminate the spurious peaks, and enhance the SNR by measuring the reactant ions. Furthermore, the gas CHCl3 and CH2Br2 were measured for evaluating the capability of detecting real sample. The results show that the NIBOHT-IMS technique is able to eliminate the spurious peaks and improve the SNR notably not only for the detection of larger ion signals but also for the detection of small ion signals.
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rapid identification of false peaks in the spectrum of Hadamard Transform ion mobility spectrometry with inverse gating technique
RSC Advances, 2015Co-Authors: Yan Hong, Chaoqun Huang, Lei Xia, Chengyin Shen, Wenqi Niu, Hui Gao, Haihe JiangAbstract:With the application of Hadamard Transform (HT) technique, the signal to noise ratio of ion mobility spectrometry (IMS) has been improved significantly. Nevertheless, possibly due to the modulation defects, false peaks appear in the demultiplexed data and demonstrate similar features to those of the real signal peaks, which makes them hard to be discriminated. Facing this challenge, a novel method has been presented in this work and achieved the rapid identification of the false peaks in Hadamard multiplexing IMS. Simply by introducing the inverse gating technique to Hadamard multiplexing, the novel inverse Hadamard Transform (IHT) method is developed. With the application of this novel method in IMS, most of the false peaks are changed to opposite to the real signal peaks, which makes them easy to be classified as the false peaks. Furthermore, with the help of the single “code” extended method, the amount of the false peaks in inverse Hadamard Transform ion mobility spectrometry (IHT-IMS) decreases dramatically, and this makes the identification more accurate. The sample tests further demonstrate that the inverse Hadamard Transform (IHT) method is an effective way to address the problem of rapid identification of the false peaks and upgrade the quality analysis of Hadamard multiplexing ion mobility spectrometry.
Aye Aung - One of the best experts on this subject based on the ideXlab platform.
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Natural-ordered complex Hadamard Transform
Signal Processing, 2010Co-Authors: Aye AungAbstract:This paper presents a new Transform known as natural-ordered complex Hadamard Transform (NCHT) which is derived from the Walsh-Hadamard Transform (WHT) through the direct block matrix operation. Some of its properties, including the exponential property of the NCHT and the shift invariant property of the NCHT power spectrum, are presented. The relationship of the NCHT with the sequency-ordered complex Hadamard Transform (SCHT) is discussed. In fact, it is shown that NCHT is a natural-ordered version of complex Hadamard Transform whereas SCHT shows the sequency ordering. This is parallel to their real-valued counterparts, the WHT and the sequency-ordered Walsh Transform (SOWT). A fast algorithm for computing the NCHT is also developed using sparse matrix factorization and its computational complexity is examined.
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sequency ordered complex Hadamard Transform properties computational complexity and applications
IEEE Transactions on Signal Processing, 2008Co-Authors: Aye Aung, Susanto RahardjaAbstract:In this paper, the generation of sequency-ordered complex Hadamard Transform (SCHT) based on the complex Rademacher matrices is presented. The exponential form of SCHT is also derived, and the proof for the unitary property of SCHT is given. Using the sparse matrix factorization, the fast and efficient algorithm to compute the SCHT Transform is developed, and its computation load is described. Certain properties of the SCHT matrices are derived and analyzed with the discussion of SCHT applications in spectrum analysis and image watermarking. Relations of SCHT with fast Fourier Transform (FFT) and unified complex Hadamard Transform (UCHT) are discussed.
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Pipelined Hardware Structure for Sequency-Ordered Complex Hadamard Transform
IEEE Signal Processing Letters, 2008Co-Authors: Aye AungAbstract:This letter presents a fast algorithm for the sequency-ordered complex Hadamard Transform (SCHT) based on the decomposition method of decimation-in-sequency. To support high-speed real-time applications, a pipelined hardware structure is also proposed to deal with sequentially presented input/output data streams. This structure achieves a full hardware utilization and requires only complex adder/subtracters and complex data stores for an N-point SCHT.
Herbert H. Hill - One of the best experts on this subject based on the ideXlab platform.
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Simulating, Predicting, and Minimizing False Peaks for Hadamard Transform Ion Mobility Spectrometry.
Journal of the American Society for Mass Spectrometry, 2020Co-Authors: Jing Guoxing, Li Wenshan, Liu Wen, Juliet Nwadiuso Okonkwo, Liu Wenjie, Herbert H. HillAbstract:Multiplexing techniques, including the Hadamard Transform, are widely used in the recovery of weak signals from high-level noise. Hadamard Transform ion mobility spectrometry (HT-IMS), however, can...
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Hadamard Transform Ion Mobility Spectrometry
Analytical chemistry, 2006Co-Authors: Brian H. Clowers, William F. Siems, Herbert H. Hill, Steven M. MassickAbstract:A detection scheme that makes use of the Hadamard Transform has been employed with an atmospheric-pressure ion mobility spectrometer fitted with an electrospray ionization source. The Hadamard Transform was implemented through the use of a linear-feedback shift register to produce a pseudorandom sequence of 1023 points. This pseudorandom sequence was applied to the ion gate of the spectrometer, and deconvolution of the ion signal was accomplished by the Hadamard Transform to reconstruct the mobility spectrum. Ion mobility spectra were collected in both a conventional and Hadamard mode, with comparisons made between the two approaches. Initial results exhibited low spectral definition, so an oversampling technique was applied to increase the number of data points across each analyte spectral peak. The use of the Hadamard Transform increases the duty cycle of the instrument to 50% and results in a roughly 5-fold enhancement of the signal-to-noise ratio with a negligible loss of instrument resolution. It is ...
Brian H. Clowers - One of the best experts on this subject based on the ideXlab platform.
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detecting and removing data artifacts in Hadamard Transform ion mobility mass spectrometry measurements
Journal of the American Society for Mass Spectrometry, 2014Co-Authors: Spencer A Prost, Brian H. Clowers, Kevin L Crowell, Erin S Baker, Yehia M Ibrahim, Matthew E Monroe, Gordon A Anderson, Richard D Smith, Samuel H PayneAbstract:Applying Hadamard Transform multiplexing to ion mobility separations (IMS) can significantly improve the signal-to-noise ratio and throughput for IMS coupled mass spectrometry (MS) measurements by increasing the ion utilization efficiency. However, it has been determined that fluctuations in ion intensity as well as spatial shifts in the multiplexed data lower the signal-to-noise ratios and appear as noise in downstream processing of the data. To address this problem, we have developed a novel algorithm that discovers and eliminates data artifacts. The algorithm employs an analytical approach to identify and remove artifacts from the data, decreasing the likelihood of false identifications in subsequent data processing. Following application of the algorithm, IMS-MS measurement sensitivity is greatly increased and artifacts that previously limited the utility of applying the Hadamard Transform to IMS are avoided.
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Hadamard Transform Ion Mobility Spectrometry
Analytical chemistry, 2006Co-Authors: Brian H. Clowers, William F. Siems, Herbert H. Hill, Steven M. MassickAbstract:A detection scheme that makes use of the Hadamard Transform has been employed with an atmospheric-pressure ion mobility spectrometer fitted with an electrospray ionization source. The Hadamard Transform was implemented through the use of a linear-feedback shift register to produce a pseudorandom sequence of 1023 points. This pseudorandom sequence was applied to the ion gate of the spectrometer, and deconvolution of the ion signal was accomplished by the Hadamard Transform to reconstruct the mobility spectrum. Ion mobility spectra were collected in both a conventional and Hadamard mode, with comparisons made between the two approaches. Initial results exhibited low spectral definition, so an oversampling technique was applied to increase the number of data points across each analyte spectral peak. The use of the Hadamard Transform increases the duty cycle of the instrument to 50% and results in a roughly 5-fold enhancement of the signal-to-noise ratio with a negligible loss of instrument resolution. It is ...
Huazhong Shu - One of the best experts on this subject based on the ideXlab platform.
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sliding conjugate symmetric sequency ordered complex Hadamard Transform fast algorithm and applications
IEEE Transactions on Circuits and Systems, 2012Co-Authors: Lu Wang, Guanyu Yang, Lotfi Senhadji, Limin Luo, Huazhong ShuAbstract:This paper presents a fast algorithm for the computation of sliding conjugate symmetric sequency-ordered complex Hadamard Transform (CS-SCHT). The algorithm calculates the values of window i+ N/4 from those of window i, one length-N/4 Walsh Hadamard Transform (WHT) and one length-N/4 Modified WHT (MWHT). The proposed algorithm requires O(N) arithmetic operations, which is more efficient than the block-based algorithms of various Transforms and the sliding FFT algorithm, but less efficient than the sliding WHT algorithms. Compared to the recently proposed sliding inverse SCHT (ISCHT) algorithm, the proposed algorithm is more efficient for real input but less efficient for complex input. The applications of the sliding CS-SCHT in Transform domain adaptive filtering (TDAF) to complex signal channel equalization and real speech signal acoustic echo cancellation are also provided.
