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Zainal Salam - One of the best experts on this subject based on the ideXlab platform.

  • a simple on line harmonics elimination pwm algorithm for a three phase voltage source inverter based on Quadratic Curve fittings
    Compel-the International Journal for Computation and Mathematics in Electrical and Electronic Engineering, 2010
    Co-Authors: Zainal Salam
    Abstract:

    Purpose – The purpose of this paper is to propose an on‐line algorithm to calculate the switching angles of the harmonics elimination pulse‐width modulation (HEPWM) scheme that can be suitably implemented using a simple microprocessor/microcontroller. It is to be used for three‐phase voltage source inverter (VSI).Design/methodology/approach – Approximate equations for the HEPWM angles are obtained by performing Quadratic Curve fittings of the trajectories of the exact HEPWM angles. This paper aims to obtain approximate equation that can be programmed on‐line using microprocessor/microcontroller.Findings – The main feature of the algorithm is simplicity, whereby only addition and multiplications functions are required. It shall be shown that the proposed scheme allows for an efficient real‐time computation with acceptable error margins. The workability of the algorithm is validated with hardware results.Practical implications – Since the algorithm allows for on‐line changes of the number of harmonics to be...

  • an on line harmonics elimination pwm scheme for three phase voltage source inverter using Quadratic Curve fitting
    Conference of the Industrial Electronics Society, 2004
    Co-Authors: Zainal Salam
    Abstract:

    An on-line harmonic elimination PWM (HEPWM) scheme for three-phase voltage source inverter is proposed. It is based on Quadratic Curve fitting of the trajectories of the exact HEPWM angles. The main advantage of the technique is that it can be efficiently implemented using a simple low cost microprocessor. An outline to obtain the approximate HEPWM switching angles is presented. To check the accuracy of the method, an error analysis is carried out. The scheme is validated by experimental results.

A. A. Abd-el Fatah - One of the best experts on this subject based on the ideXlab platform.

  • Determination of capsaicin, dihydrocapsaicin, and nonivamide in self-defense weapons by liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry
    Journal of Chromatography A, 2001
    Co-Authors: Christopher A Reilly, Dennis J Crouch, Garold S Yost, A. A. Abd-el Fatah
    Abstract:

    Sensitive and selective liquid chromatography–mass spectrometry (LC–MS) and liquid chromatography–tandem mass spectrometry (LC–MS–MS) methods for the analysis of capsaicin, dihydrocapsaicin, and nonivamide in pepper spray products have been developed. Chromatographic separation of the capsaicinoid analogues was achieved using a reversed-phase HPLC column and a stepwise gradient of methanol and distilled water containing 0.1% (v/v) formic acid. Identification and quantification of the capsaicinoids was achieved by electrospray ionization single-stage mass spectrometry monitoring the protonated molecules of the internal standard (m/z 280), capsaicin (m/z 306), dihydrocapsaicin (m/z 308), and nonivamide (m/z 294) or by tandem mass spectrometry monitoring the appropriate precursor-to-product-ion transitions. The plot of concentration versus peak area ratio was linear over the range of 10–750 ng/ml using LC–MS and 10–500 ng/ml using LC–MS–MS. However, to accurately quantify the capsaicinoids in the pepper spray products calibration Curves between 10 and 1000 ng were constructed and fit using a weighted Quadratic equation. Using the Quadratic Curve, the accuracy of the assay ranged from 91 to 102% for all analytes. The intra-assay precision (RSD) for capsaicin was 2% at 25 ng/ml, 10% at 500 ng/ml, and 3% at 800 ng/ml. The inter-assay precision (RSD) for capsaicin was 6% at 25 ng/ml, 6% at 500 ng/ml, and 9% at 800 ng/ml. Similar values for inter- and intra-assay precision were experimentally obtained for both dihydrocapsaicin and nonivamide. The analysis of selected pepper spray products demonstrated that the capsaicinoid concentration in the products ranged from 0.7 to 40.5 μg/μl.

Heinrich F Arlinghaus - One of the best experts on this subject based on the ideXlab platform.

  • implementation and optimization of large gas cluster laser post ionization secondary neutral mass spectrometry for molecular analysis
    Journal of Physical Chemistry C, 2017
    Co-Authors: Andreas Pelster, Martin Korsgen, Marcel Heeger, Heinrich F Arlinghaus
    Abstract:

    In this study, we describe for the first time a new combined technique for molecular surface analysis using large argon gas clusters as primary ions for laser postionization secondary neutral mass spectrometry (Laser-SNMS). This new technique was investigated on polymer polystyrene (PS) surfaces using pulsed Ar2000+ ions with 20 keV energy and a 157 nm laser beam for postionization. To optimize the ion yield, time-of-flight (ToF) distributions of characteristic sputtered neutral PS fragments were determined. The data could be fitted well with Maxwell–Boltzmann distributions. The data show that the maxima of the individual ToF distributions of the sputtered neutrals move to higher delay time values with increasing mass, which directly correlates to a decrease of velocity of the sputtered neutrals with increasing mass. The delay time dependence on mass could be fitted with a Quadratic Curve, thus indicating a constant mean kinetic energy for the sputtered molecules. The ion yields obtained with large gas cl...

Yan He - One of the best experts on this subject based on the ideXlab platform.

  • haptic data compression based on a linear prediction model and Quadratic Curve reconstruction
    Journal of Software, 2014
    Co-Authors: Caiming Zhang, Yan He
    Abstract:

    In this paper, a new haptic data compression technique is presented. The algorithm partitions haptic data samples into subsets while relying on knowledge from human haptic perception. To reduce the number of data subsets, a prediction model based on a tangential direction concept is derived that adapts to local geometric changes of haptic signals. Furthermore, to improve signal approximation precision, each haptic data subset is fitted by a Quadratic Curve. Accordingly, only the coefficents of the Quadratic Curves are encoded. Experiments are performed on datasets acquired using a six-degrees-of-freedom haptic-enabled telepresence system. The experimental results demonstrated that the proposed haptic data compression algorithm can potentially outperform related methods in the literature.

  • haptic data compression based on Quadratic Curve reconstruction and prediction
    International Conference on Internet Multimedia Computing and Service, 2011
    Co-Authors: Yan He, Nizar Sakr, Jiying Zhao, Abdulmotaleb El Saddik
    Abstract:

    In this paper, a novel haptic data compression method is presented. A linear prediction model based on a tangential direction concept is derived that adapts to local geometric changes of haptic data samples. The suggested data compression strategy further relies on a Quadratic Curve reconstruction strategy to improve signal approximation. Knowledge from human haptic perception is incorporated into the technique to ensure that compression artifacts remain imperceptible to the user. The experimental results demonstrated that the proposed haptic data reduction strategy can potentially outperform other related methods in the literature.

  • haptic data compression based on Curve reconstruction
    Autonomous and Intelligent Systems, 2011
    Co-Authors: Yan He, Nizar Sakr, Jiying Zhao, Abdulmotaleb El Saddik
    Abstract:

    In this paper, the problem of haptic data compression is addressed. The algorithm partitions haptic data samples into subsets while relying on knowledge from human haptic perception. A geometric distance-based approach is used to reduce the number of haptic data subsets. In particular, to improve approximation precision, each haptic data subset is fitted by a Quadratic Curve. Accordingly, rather than directly using the original haptic data, only the coefficients of the Quadratic Curves are stored or transmitted. Experiments are performed to compare the suggested Curve reconstruction method with the more common linear method. The results prove the effectiveness of the proposed approach in improving data reduction rate and approximation precision.

Abdulmotaleb El Saddik - One of the best experts on this subject based on the ideXlab platform.

  • haptic data compression based on Quadratic Curve reconstruction and prediction
    International Conference on Internet Multimedia Computing and Service, 2011
    Co-Authors: Yan He, Nizar Sakr, Jiying Zhao, Abdulmotaleb El Saddik
    Abstract:

    In this paper, a novel haptic data compression method is presented. A linear prediction model based on a tangential direction concept is derived that adapts to local geometric changes of haptic data samples. The suggested data compression strategy further relies on a Quadratic Curve reconstruction strategy to improve signal approximation. Knowledge from human haptic perception is incorporated into the technique to ensure that compression artifacts remain imperceptible to the user. The experimental results demonstrated that the proposed haptic data reduction strategy can potentially outperform other related methods in the literature.

  • haptic data compression based on Curve reconstruction
    Autonomous and Intelligent Systems, 2011
    Co-Authors: Yan He, Nizar Sakr, Jiying Zhao, Abdulmotaleb El Saddik
    Abstract:

    In this paper, the problem of haptic data compression is addressed. The algorithm partitions haptic data samples into subsets while relying on knowledge from human haptic perception. A geometric distance-based approach is used to reduce the number of haptic data subsets. In particular, to improve approximation precision, each haptic data subset is fitted by a Quadratic Curve. Accordingly, rather than directly using the original haptic data, only the coefficients of the Quadratic Curves are stored or transmitted. Experiments are performed to compare the suggested Curve reconstruction method with the more common linear method. The results prove the effectiveness of the proposed approach in improving data reduction rate and approximation precision.