Pseudo-differential operators(PDO)Q(x,L_(a,x))and Q(x,L_(a,x))involving the index Whittaker transform are defined.Estimates for these operators in Hilbert space L_(2)^(a)(R+;m_(a)(x)dx)are obtained.A symbol classΩis ...Pseudo-differential operators(PDO)Q(x,L_(a,x))and Q(x,L_(a,x))involving the index Whittaker transform are defined.Estimates for these operators in Hilbert space L_(2)^(a)(R+;m_(a)(x)dx)are obtained.A symbol classΩis introduced.Later product and commutators for the PDO are investigated and their boundedness results are discussed.展开更多
The IEEE 802.16d communication standard uses orthogonal frequency division multiplexing （OFDM）. In the widely used OFDM systems, the fast Fourier transform （FFT） and inverse fast Fourier transform pairs are used t...The IEEE 802.16d communication standard uses orthogonal frequency division multiplexing （OFDM）. In the widely used OFDM systems, the fast Fourier transform （FFT） and inverse fast Fourier transform pairs are used to modulate and demodulate the data constellation on the sub-carriers. In this paper, a high level implementation of a high performance FFT for OFDM modulator and demodulator is presented. The design has been coded in Verilog and targeted into Xilinx Spartan3 field programmable gate arrays. Radix-22 algorithm is proposed and used for the OFDM communication system. The design of the FFT is implemented and applied to fixed WiMAX--IEEE 802.16d communi- cation standard. The results are tabulated and the hardware parameters are compared. The proposed architecture is least in number of multipliers used and the memory size, and second to the least in number of adders used.展开更多
In this paper, error modeling and analysis of a typical 3-degree of freedom translational Parallel Kine- matic Machine is presented. This mechanism provides translational motion along the Cartesian X-, Y- and Z- axes....In this paper, error modeling and analysis of a typical 3-degree of freedom translational Parallel Kine- matic Machine is presented. This mechanism provides translational motion along the Cartesian X-, Y- and Z- axes. It consists of three limbs each having an arm and forearm with prismatic-revolute-revolute-revolute joints. The moving or tool platform maintains same orientation in the entire workspace due to its joint arrangement. From inverse kinematics, the joint angles for a given position of tool platform necessary for the error modeling and analysis are obtained. Error modeling is done based on the differentiation of the inverse kinematic equations. Variation of pose errors along X, Y and Z directions for a set of dimensions of the parallel kinematic machine is presented. A non-dimensional performance index, namely, global error transformation index is used to study the influence of dimensions and its corresponding global maximum pose error is reported. An attempt is made to find the optimal dimensions of the Parallel Kinematic Machine using Genetic Algorithms in MATLAB. The methodology presented and the results obtained are useful for predicting the performance capability of the Parallel Kinematic Machine under study.展开更多
基金supported by Science and Engineering Research Board,Government of India,under Grant No.EMR/2016/005141。
文摘Pseudo-differential operators(PDO)Q(x,L_(a,x))and Q(x,L_(a,x))involving the index Whittaker transform are defined.Estimates for these operators in Hilbert space L_(2)^(a)(R+;m_(a)(x)dx)are obtained.A symbol classΩis introduced.Later product and commutators for the PDO are investigated and their boundedness results are discussed.
文摘The IEEE 802.16d communication standard uses orthogonal frequency division multiplexing （OFDM）. In the widely used OFDM systems, the fast Fourier transform （FFT） and inverse fast Fourier transform pairs are used to modulate and demodulate the data constellation on the sub-carriers. In this paper, a high level implementation of a high performance FFT for OFDM modulator and demodulator is presented. The design has been coded in Verilog and targeted into Xilinx Spartan3 field programmable gate arrays. Radix-22 algorithm is proposed and used for the OFDM communication system. The design of the FFT is implemented and applied to fixed WiMAX--IEEE 802.16d communi- cation standard. The results are tabulated and the hardware parameters are compared. The proposed architecture is least in number of multipliers used and the memory size, and second to the least in number of adders used.
文摘In this paper, error modeling and analysis of a typical 3-degree of freedom translational Parallel Kine- matic Machine is presented. This mechanism provides translational motion along the Cartesian X-, Y- and Z- axes. It consists of three limbs each having an arm and forearm with prismatic-revolute-revolute-revolute joints. The moving or tool platform maintains same orientation in the entire workspace due to its joint arrangement. From inverse kinematics, the joint angles for a given position of tool platform necessary for the error modeling and analysis are obtained. Error modeling is done based on the differentiation of the inverse kinematic equations. Variation of pose errors along X, Y and Z directions for a set of dimensions of the parallel kinematic machine is presented. A non-dimensional performance index, namely, global error transformation index is used to study the influence of dimensions and its corresponding global maximum pose error is reported. An attempt is made to find the optimal dimensions of the Parallel Kinematic Machine using Genetic Algorithms in MATLAB. The methodology presented and the results obtained are useful for predicting the performance capability of the Parallel Kinematic Machine under study.
