The Experts below are selected from a list of 372 Experts worldwide ranked by ideXlab platform

Frank Glorius - One of the best experts on this subject based on the ideXlab platform.

  • ruthenium nhc diamine catalyzed enantioselective hydrogenation of isocoumarins
    Journal of the American Chemical Society, 2017
    Co-Authors: Wei Li, Mario P. Wiesenfeldt, Frank Glorius
    Abstract:

    A novel and practical chiral ruthenium–NHC–diamine system is disclosed for the enantioselective hydrogenation of isocoumarins, which provides a new concept to apply (chiral) NHC ligands in asymmetric catalysis. A variety of optically active 3-substituted 3,4-dihydroisocoumarins were obtained in excellent enantioselectivities (up to 99% ee). Moreover, this methodology was utilized in the synthesis of O-methylMellein, Mellein, and ochratoxin A.

  • Ruthenium–NHC–Diamine Catalyzed Enantioselective Hydrogenation of Isocoumarins
    2017
    Co-Authors: Mario P. Wiesenfeldt, Frank Glorius
    Abstract:

    A novel and practical chiral ruthenium–NHC–diamine system is disclosed for the enantioselective hydrogenation of isocoumarins, which provides a new concept to apply (chiral) NHC ligands in asymmetric catalysis. A variety of optically active 3-substituted 3,4-dihydroisocoumarins were obtained in excellent enantioselectivities (up to 99% ee). Moreover, this methodology was utilized in the synthesis of O-methylMellein, Mellein, and ochratoxin A

Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.

  • probability distributions of products of rayleigh and nakagami m variables using mellin transform
    International Conference on Communications, 2011
    Co-Authors: Sohail Ahmed, Lieliang Yang, Lajos Hanzo
    Abstract:

    In this contribution, we employ the Mellin transform to derive the expressions for probability density function (PDF) of the product of Nakagami-m and Gamma distributed random variables. As the special cases of the Nakagami-m and Gamma family, the PDF of the product of Rayleigh distributed random variables and that of the product of exponentially distributed Random variables are also derived. We exploit the fact that the Mellin transform of a product of independent and identically distributed random variables is the product of the Mellin transforms of the individual random variables. Using this approach, the PDF of the product of random variables is expressed in the form of an easily computable infinite series. Furthermore, application of the PDFs in digital communications using M-ary orthogonal modulation is illustrated.

  • mellin transform based performance analysis of ffh m ary fsk using product combining for combatting partial band noise jamming
    IEEE Transactions on Vehicular Technology, 2008
    Co-Authors: Sohail Ahmed, Lieliang Yang, Lajos Hanzo
    Abstract:

    We employ the Mellin transform to facilitate the bit error ratio (BER) analysis of a fast frequency hopping (FFH)-assisted, M-ary frequency-shift keying (MFSK) using product combining (PC) when the transmitted signal is subjected to both Rayleigh fading and partial-band noise jamming. Exploiting the fact that the Mellin transform of the product of independent random variables is the product of their Mellin transforms, we derive the probability density function (PDF) of the PC's output. The derivation of the PDF then allows the computation of the system's BER. It is shown that the Mellin transform substantially simplifies the analysis of the PC receiver and hence facilitates, for the first time, the analysis of the FFH-MFSK PC receiver for modulation orders of M > 2.

  • mellin transform based performance analysis of ffh m ary fsk using product combining against partial band noise jamming
    Vehicular Technology Conference, 2007
    Co-Authors: Sohail Ahmed, Lieliang Yang, Lajos Hanzo
    Abstract:

    We propose a novel bit error ratio (BER) analysis technique for fast frequency hopping (FFH) assisted M-ary frequency shift keying (MFSK) using product combining (PC), when the channel is contaminated by partial band noise jamming (PBNJ). Exploiting the fact that the Mellin transform of the product of independent random variables is the product of their Mellin transforms, we derive the probability density function (PDF) of the PC's output, when communicating in uncorrelated Rayleigh fading channels contaminated by PBNJ. The derivation of the PDF thus allows computation of the system's BER. It is shown that the Mellin transform substantially simplifies the analysis of the PC receiver and facilitates for the first time the analysis of FFH-MFSK PC receiver for modulation orders of M > 2.

Sohail Ahmed - One of the best experts on this subject based on the ideXlab platform.

  • probability distributions of products of rayleigh and nakagami m variables using mellin transform
    International Conference on Communications, 2011
    Co-Authors: Sohail Ahmed, Lieliang Yang, Lajos Hanzo
    Abstract:

    In this contribution, we employ the Mellin transform to derive the expressions for probability density function (PDF) of the product of Nakagami-m and Gamma distributed random variables. As the special cases of the Nakagami-m and Gamma family, the PDF of the product of Rayleigh distributed random variables and that of the product of exponentially distributed Random variables are also derived. We exploit the fact that the Mellin transform of a product of independent and identically distributed random variables is the product of the Mellin transforms of the individual random variables. Using this approach, the PDF of the product of random variables is expressed in the form of an easily computable infinite series. Furthermore, application of the PDFs in digital communications using M-ary orthogonal modulation is illustrated.

  • mellin transform based performance analysis of ffh m ary fsk using product combining for combatting partial band noise jamming
    IEEE Transactions on Vehicular Technology, 2008
    Co-Authors: Sohail Ahmed, Lieliang Yang, Lajos Hanzo
    Abstract:

    We employ the Mellin transform to facilitate the bit error ratio (BER) analysis of a fast frequency hopping (FFH)-assisted, M-ary frequency-shift keying (MFSK) using product combining (PC) when the transmitted signal is subjected to both Rayleigh fading and partial-band noise jamming. Exploiting the fact that the Mellin transform of the product of independent random variables is the product of their Mellin transforms, we derive the probability density function (PDF) of the PC's output. The derivation of the PDF then allows the computation of the system's BER. It is shown that the Mellin transform substantially simplifies the analysis of the PC receiver and hence facilitates, for the first time, the analysis of the FFH-MFSK PC receiver for modulation orders of M > 2.

  • mellin transform based performance analysis of ffh m ary fsk using product combining against partial band noise jamming
    Vehicular Technology Conference, 2007
    Co-Authors: Sohail Ahmed, Lieliang Yang, Lajos Hanzo
    Abstract:

    We propose a novel bit error ratio (BER) analysis technique for fast frequency hopping (FFH) assisted M-ary frequency shift keying (MFSK) using product combining (PC), when the channel is contaminated by partial band noise jamming (PBNJ). Exploiting the fact that the Mellin transform of the product of independent random variables is the product of their Mellin transforms, we derive the probability density function (PDF) of the PC's output, when communicating in uncorrelated Rayleigh fading channels contaminated by PBNJ. The derivation of the PDF thus allows computation of the system's BER. It is shown that the Mellin transform substantially simplifies the analysis of the PC receiver and facilitates for the first time the analysis of FFH-MFSK PC receiver for modulation orders of M > 2.

Carlo Bardaro - One of the best experts on this subject based on the ideXlab platform.

  • a residue theorem for polar analytic functions and mellin analogues of boas differentiation formula and valiron s sampling formula
    arXiv: Complex Variables, 2019
    Co-Authors: Carlo Bardaro, Paul L Butzer, Ilaria Mantellini, Gerhard Schmeisser
    Abstract:

    In this paper, we continue the study of the polar analytic functions, a notion introduced in \cite{BBMS1} and successfully applied in Mellin analysis. Here we obtain another version of the Cauchy integral formula and a residue theorem for polar Mellin derivatives, employing the new notion of logarithmic pole. The identity theorem for polar analytic functions is also derived. As applications we obtain an analogue of Boas' differentiation formula for polar Mellin derivatives, and an extension of the classical Bernstein inequality to polar Mellin derivatives. Finally we give an analogue of the well-know Valiron sampling theorem for polar analytic functions and some its consequences.

  • a fresh approach to the paley wiener theorem for mellin transforms and the mellin hardy spaces
    arXiv: Functional Analysis, 2017
    Co-Authors: Carlo Bardaro, Paul L Butzer, Ilaria Mantellini, Gerhard Schmeisser
    Abstract:

    Here we give a new approach to the Paley--Wiener theorem in a Mellin analysis setting which avoids the use of the Riemann surface of the logarithm and analytical branches and is based on new concepts of "polar-analytic function" in the Mellin setting and Mellin--Bernstein spaces. A notion of Hardy spaces in the Mellin setting is also given along with applications to exponential sampling formulas of optical physics.

  • On the Paley-Wiener theorem in the Mellin transform setting
    Journal of Approximation Theory, 2016
    Co-Authors: Carlo Bardaro, Paul L Butzer, Ilaria Mantellini, Gerhard Schmeisser
    Abstract:

    In this paper we establish a version of the Paley-Wiener theorem of Fourier analysis in the frame of Mellin transforms. We provide two different proofs, one involving complex analysis arguments, namely the Riemann surface of the logarithm and Cauchy theorems, and the other one employing a Bernstein inequality here derived for Mellin derivatives.

  • the mellin parseval formula and its interconnections with the exponential sampling theorem of optical physics
    Integral Transforms and Special Functions, 2016
    Co-Authors: Carlo Bardaro, Paul L Butzer, Ilaria Mantellini
    Abstract:

    ABSTRACTIn this paper, we establish a Mellin version of the classical Parseval formula of Fourier analysis in the case of Mellin bandlimited functions, and its equivalence with the exponential sampling formula (ESF) of signal analysis, in which the samples are not equally spaced apart as in the classical Shannon theorem, but exponentially spaced. Two quite different examples are given illustrating the truncation error in the ESF. We employ Mellin transform methods for square-integrable functions.

  • The Foundations of Fractional Calculus in the Mellin Transform Setting with Applications
    Journal of Fourier Analysis and Applications, 2015
    Co-Authors: Carlo Bardaro, Paul L Butzer, Ilaria Mantellini
    Abstract:

    In this article we study the basic theoretical properties of Mellin-type fractional integrals, known as generalizations of the Hadamard-type fractional integrals. We give a new approach and version, specifying their semigroup property, their domain and range. Moreover we introduce a notion of strong fractional Mellin derivatives and we study the connections with the pointwise fractional Mellin derivative, which is defined by means of Hadamard-type fractional integrals. One of the main results is a fractional version of the fundamental theorem of differential and integral calculus in the Mellin frame. In fact, in this article it will be shown that the very foundations of Mellin transform theory and the corresponding analysis are quite different to those of the Fourier transform, alone since even in the simplest non-fractional case the integral operator (i.e. the anti-differentiation operator) applied to a function $$f$$ f will turn out to be the $$\int _0^x f(u)du/u$$ ∫ 0 x f ( u ) d u / u with derivative $$(xd/dx)f(x).$$ ( x d / d x ) f ( x ) . Thus the fundamental theorem in the Mellin sense is valid in this form, one which stands apart from the classical Newtonian integral and derivative. Among the applications two fractional order partial differential equations are studied.

Wei Li - One of the best experts on this subject based on the ideXlab platform.

  • ruthenium nhc diamine catalyzed enantioselective hydrogenation of isocoumarins
    Journal of the American Chemical Society, 2017
    Co-Authors: Wei Li, Mario P. Wiesenfeldt, Frank Glorius
    Abstract:

    A novel and practical chiral ruthenium–NHC–diamine system is disclosed for the enantioselective hydrogenation of isocoumarins, which provides a new concept to apply (chiral) NHC ligands in asymmetric catalysis. A variety of optically active 3-substituted 3,4-dihydroisocoumarins were obtained in excellent enantioselectivities (up to 99% ee). Moreover, this methodology was utilized in the synthesis of O-methylMellein, Mellein, and ochratoxin A.