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Search Results: 1 - 10 of 28106 matches for " Bao Song "
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Effects of Buoyancy on Langmuir Circulation

SONG Jun,SONG Jin-Bao,

中国物理快报 , 2008,
Abstract: Based on the Navier--Stokes equation, an equation describing the Langmuir circulation is derived by a perturbation method when the influences of Coriolisforce and buoyancy force are both considered. The approach used in the analysis is similar to the works carried out by Craik and Leibovich J. Fluid Mech. 73(1976)401], Leibovich J. Fluid Mech. 79(1977)715] and Huang J. Fluid Mech. 91(1979)191]. Potential applications of the equation proposed are discussed in the area of Antarctic circumpolar current.
A set of Boussinesq-type equations for interfacial internal waves in two-layer stratified fluid
Song Jin-Bao,
宋金宝

中国物理 B , 2006,
Abstract: Many new forms of Boussinesq-type equations have been developed to extend the range of applicability of the classical Boussinesq equations to deeper water in the study of the surface waves. One approach was used by Nwogu (1993. J. Wtrw. Port Coastal and Oc. Eng. 119, 618--638) to improve the linear dispersion characteristics of the classical Boussinesq equations by using the velocity at an arbitrary level as the velocity variable in derived equations and obtain a new form of Boussinesq-type equations, in which the dispersion property can be optimized by choosing the velocity variable at an adequate level. In this paper, a set of Boussinesq-type equations describing the motions of the interfacial waves propagating alone the interface between two homogeneous incompressible and inviscid fluids of different densities with a free surface and a variable water depth were derived using a method similar to that used by Nwogu (1993. J. Wtrw. Port Coastal and Oc. Eng. 119, 618--638) for surface waves. The equations were expressed in terms of the displacements of free surface and density-interface, and the velocity vectors at arbitrary vertical locations in the upper layer and the lower layer (or depth-averaged velocity vector across each layer) of a two-layer fluid. As expected, the equations derived in the present work include as special cases those obtained by Nwogu (1993, J. Wtrw. Port Coastal and Oc. Eng. 119, 618-638) and Peregrine (1967, J. Fluid Mech. 27, 815-827) for surface waves when the density of the upper fluid is taken as zero.
Adaptive PIF Control for Permanent Magnet Synchronous Motors Based on GPC
Shaowu Lu,Xiaoqi Tang,Bao Song
Sensors , 2013, DOI: 10.3390/s130100175
Abstract: To enhance the control performance of permanent magnet synchronous motors (PMSMs), a generalized predictive control (GPC)-based proportional integral feedforward (PIF) controller is proposed for the speed control system. In this new approach, firstly, based on the online?identification of controlled model parameters, a simplified GPC law supplies the PIF controller with suitable control parameters according to the uncertainties in the operating conditions. Secondly, the speed reference curve for PMSMs is usually required to be continuous and continuously differentiable according to the general servo system design requirements, so the adaptation of the speed reference is discussed in details in this paper. Hence, the performance of the speed control system using a GPC-based PIF controller is improved for tracking some specified signals. The main motivation of this paper is the extension of GPC law to replace the traditional PI or PIF controllers in industrial applications. The efficacy and usefulness of the proposed controller are verified through experimental results.
Tracking control of a flexible beam by nonlinear boundary feedback
Bao-Zhu Guo,Qian Song
International Journal of Stochastic Analysis , 1995, DOI: 10.1155/s1048953395000049
Abstract: This paper is concerned with tracking control of a dynamic model consisting of a flexible beam rotated by a motor in a horizontal plane at the one end and a tip body rigidly attached at the free end. The well-posedness of the closed loop systems considering the dissipative nonlinear boundary feedback is discussed and the asymptotic stability about difference energy of the hybrid system is also investigated.
QoE-based resource allocation protocolsin cognitive OFDMA network with hybrid model
Bao Xu, Zhang Lei, Song Tiecheng
- , 2015, DOI: 10.3969/j.issn.1003-7985.2015.01.001
Abstract: A resource allocation protocol is presented in an orthogonal frequency division multiple access(OFDMA)cognitive radio(CR)network with a hybrid model which combines overlay and underlay models. Without disrupting the primary user(PU)transmissions, the overlay model allows the secondary user(SU)to utilize opportunistically the idle sub-channels; the underlay model allows the SU to occupy the same sub-channels with PU. The proposed protocols are designed for maximizing the quality of experience(QoE)of CR users and switching dynamically between the overlay and underlay models. QoE is measured by the mean opinion score(MOS)rather than simply fulfilling the physical and medium access control(MAC)layer requirements. The simulations considering the file transfer and video stream services show that the proposed resource allocation strategy is spectrum efficient.
Synthesis of biodiesel from Jatropha curcas L. seed oil using artificial zeolites loaded with CH3COOK as a heterogeneous catalyst  [PDF]
Wei Xue, You-Chun Zhou, Bao-An Song, Xia Shi, Jun Wang, Shi-Tao Yin, De-Yu Hu, Lin-Hong Jin, Song Yang
Natural Science (NS) , 2009, DOI: 10.4236/ns.2009.11010
Abstract: An environmentally benign process was devel-oped for the transesterification of Jatropha curcas L. seed oil with methanol using artificial zeolites loaded with potassium acetate as a heterogeneous catalyst. After calcination for 5 h at 823 K, the catalyst loaded with 47 wt.% CH3COOK exhibited the highest efficiency and best catalytic activity. The easily prepared cata-lysts were characterized by means of X-ray dif-fraction and IR spectroscopy, as well as Hammett indicator titration. The results revealed a strong dependence of catalytic activity on ba-sicity. The optimum reaction conditions for transesterification of J. curcas oil were also in-vestigated. The methyl ester content in the bio-diesel product exceeded 91% after 4h reaction at reflux temperature in the presence of 2% solid catalyst and no water washing process is needed during workup.
Robust Feedback Zoom Tracking for Digital Video Surveillance
Tengyue Zou,Xiaoqi Tang,Bao Song,Jin Wang,Jihong Chen
Sensors , 2012, DOI: 10.3390/s120608073
Abstract: Zoom tracking is an important function in video surveillance, particularly in traffic management and security monitoring. It involves keeping an object of interest in focus during the zoom operation. Zoom tracking is typically achieved by moving the zoom and focus motors in lenses following the so-called “trace curve”, which shows the in-focus motor positions versus the zoom motor positions for a specific object distance. The main task of a zoom tracking approach is to accurately estimate the trace curve for the specified object. Because a proportional integral derivative (PID) controller has historically been considered to be the best controller in the absence of knowledge of the underlying process and its high-quality performance in motor control, in this paper, we propose a novel feedback zoom tracking (FZT) approach based on the geometric trace curve estimation and PID feedback controller. The performance of this approach is compared with existing zoom tracking methods in digital video surveillance. The real-time implementation results obtained on an actual digital video platform indicate that the developed FZT approach not only solves the traditional one-to-many mapping problem without pre-training but also improves the robustness for tracking moving or switching objects which is the key challenge in video surveillance.
Hybrid plant regeneration from interfamilial somatic hybridization between grapevine (vitia vinifera L.) and Red Thorowax (Bupleurum scorzonerifolium willd)
Xiquan Song,Guangmin Xia,Aifen Zhou,Xuezhen Bao,Huimin Chen
Chinese Science Bulletin , 1999, DOI: 10.1007/BF02886345
Abstract: The protoplasts of Red Thorowax (Bupleurum scorzonerifolium) irradiated by ultraviolet light (UV) at an intensity of 260 μW/cm2 for 0, 1,2 and 3 min respectively were fused with that of grapevine (Vitia vinifera). The regenerated 19 clones, every one derived from a single fused cell, were identified as hybrids by phenotype, isozyme, chromosome and 5S rDNA spacer region analysis. The results reveal that all of them are somatic hybrids. 11 hybrid calli including asymmetric and symmetric products regenerated somatic embryos and young leaves after 5 months of culture, of which 4 hybrid cell lines derived from asymmetric fusion regenerated plants with roots after 8–10 months of culture. Inspection of chromosome showed that regeneration of whole plant was related to the decrease of chromosome number. Identification of 5S rDNA spacer region of the plants confirmed that they were interfamilial hybrid plants.
Focusing of tandem bistatic SAR data using the chirp-scaling algorithm
Shichao Chen, Mengdao Xing, Song Zhou, Lei Zhang and Zheng Bao
EURASIP Journal on Advances in Signal Processing , 2013, DOI: 10.1186/1687-6180-2013-38
Abstract: Based on an exact analytical bistatic point target spectrum, an efficient chirp-scaling algorithm is proposed to correct the range cell migration of different range gates to the one of the reference range for tandem bistatic synthetic aperture radar data processing. The length of the baseline (baseline to range ratio) does not give a direct influence to the proposed algorithm, which can be applied to the processing of tandem bistatic data with a large baseline even when the baseline is equal to the range. No interpolation is needed during the entire processing, only fast Fourier transforms and phase multiplications are needed, which result in efficiency. The validity of the proposed algorithm has been verified by simulated experiments.
t-bit semiclassical quantum Fourier transform
XiangQun Fu,WanSu Bao,Chun Zhou,Zhen Song
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-011-4692-8
Abstract: Because of the difficulty of building a high-dimensional quantum register, this paper presents an implementation of the high-dimensional quantum Fourier transform (QFT) based on a low-dimensional quantum register. First, we define the t-bit semiclassical quantum Fourier transform. In terms of probability amplitude, we prove that the transform can realize quantum Fourier transformation, illustrate that the requirement for the two-qubit gate reduces obviously, and further design a quantum circuit of the transform. Combining the classical fixed-window method and the implementation of Shor’s quantum factorization algorithm, we then redesign a circuit for Shor’s algorithm, whose required computation resource is approximately equal to that of Parker’s. The requirement for elementary quantum gates for Parker’s algorithm is O( log N 3, and the quantum register for our circuit requires t 1 more dimensions than Parker’s. However, our circuit is t 2 times as fast as Parker’s, where t is the width of the window.
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