In this letter, a new and accurate frequency estimation method of complex exponential signals is proposed. The proposed method divides the signal samples into several identical segments and sums up the samples belongi...
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In this letter, a new and accurate frequency estimation method of complex exponential signals is proposed. The proposed method divides the signal samples into several identical segments and sums up the samples belonging to the same segment respectively. Then it utilizes fast Fourier transform (FFT) algorithm with zero-padding to obtain a coarse estimation, and exploits three Fourier coefficients to interpolate a fine estimation based on least square error (LSE) criterion. Numerical results show that the proposed method can closely approach the Cramer-Rao bound (CRB) at low signal-to-noise ratios (SNRs) with different estimation ranges. Furthermore, the computational complexity of the proposed method is proportional to the estimation range, showing its practical-oriented ability. The proposed method can be useful in several applications involving carrier frequency offset (CFO) estimation for burst-mode satellite communications.
Network reconfiguration and demand response can both reduce the loss and improve the security of the distribution networks (DNs). In this paper, we describe a day-ahead DN reconfiguration schedule model considering de...
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ISBN:
(纸本)9781538656860
Network reconfiguration and demand response can both reduce the loss and improve the security of the distribution networks (DNs). In this paper, we describe a day-ahead DN reconfiguration schedule model considering demand response, in which network reconfiguration is conducted by distribution system operator (DSO) while the demand response strategies are realized by customer aggregators. To preserve information privacy and reduce computational burden, a two-level decomposition & coordination algorithm is proposed to solve this model, which is based on a log-barrier cost function. In the upper level, the DSO optimizes the network reconfiguration schedule, calculates the barrier cost of every load bus and then sends it to the corresponding customer aggregator. In the lower level, every customer aggregator exploits available controllable demands like heat pump (HP), electric vehicle (EV) to minimize the nodal daily cost based on the barrier cost calculated in DSO. Numerical tests verify the promising convergence of this decomposition algorithm and show a reduction of the total cost in DN.
Two new baccharane-type glycosides（1 and 2）, together with seven known baccharane-type glycosides （3u9） hosenkoside A, hosenkoside B, hosenkoside C, hosenkoside F, hosenkoside M, hosenkoside K and hosenko- side G ...
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Two new baccharane-type glycosides（1 and 2）, together with seven known baccharane-type glycosides （3u9） hosenkoside A, hosenkoside B, hosenkoside C, hosenkoside F, hosenkoside M, hosenkoside K and hosenko- side G were isolated from the dried seeds of Impatientis balsamina L. The new baccharane-type glycosides were identified as honsenkol A-3-O-β-D-glucopyranosyl-26-O-p-D-glucopyranosyl-28-O-β-D-glucopyranosyl-O-β-D- glucopyranosyl（1） and （3S,4R,17R,20S）17-hydrroxy-3-O-β-D-xylopyranose（12）-β-D-glucopyranosyl-26-O-β-D- glucopyranosyl-28-O-β-D-glucopyranosyl-21,24-epoxybaccharane（2）, respectively, by spectroscopic methods, in- cluding NMR（1D and 2D）, IR and HR-ESI-MS. Compounds 1 and 2 were evaluated for in vitro inhibitory activity against the cell lines. Compound 2 with a new baccharane skeleton had anti-hepatic fibrosis activity against A375 cells in bioassay results, which means the new compounds have potential value in antitumor applications.
A double-turn coil omnidirectional shear-horizontal wave magnetostrictive patch transducer (DC-OSH-MPT) array for imaging detection in composite plates is presented. DC-OSH-MPT parameters are optimized in order to mak...
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A double-turn coil omnidirectional shear-horizontal wave magnetostrictive patch transducer (DC-OSH-MPT) array for imaging detection in composite plates is presented. DC-OSH-MPT parameters are optimized in order to make the transducer more suitable for imaging detection. Besides, the characteristic of the lowest shear-horizontal mode (SH0), which can be generated and received in all directions by DC-OSH-MPT bonded on composite plate, is beneficial for imaging. Due to anisotropic property of composite plates, the group velocity of SH0 mode in different azimuthal directions was experimentally measured in damage imaging. The location of simulated damage, which was a bonded circular cylinder, was estimated by DC-OSH-MPT array and ellipse imaging algorithm. The imaging results have demonstrated that DC-OSH-MPT can be considered as a spatially distributed array suitable for imaging detection in composite plates.
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