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Search Results: 1 - 10 of 36692 matches for " Xiao Dongpo "
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Network value and optimum analysis on the mode of networked marketing in TV media
Xiao Dongpo,Zhenji Zhang,Xiaolan Guan
Journal of Industrial Engineering and Management , 2012, DOI: 10.3926/jiem.615
Abstract: Purpose: With the development of the networked marketing in TV media, it is important to do the research on network value and optimum analysis in this field. Design/methodology/approach: According to the research on the mode of networked marketing in TV media and Correlation theory, the essence of media marketing is creating, spreading and transferring values. The Participants of marketing value activities are in network, and value activities proceed in networked form. Network capability is important to TV media marketing activities. Findings: This article raises the direction of research of analysis and optimization about network based on the mode of networked marketing in TV media by studying TV media marketing Development Mechanism , network analysis and network value structure.
Study on the Corrosion Inhibition Characteristic of ZH and ZG Mannich Base Inhibitors  [PDF]
Shusheng Zhou, Kehua Li, Tiantian Tang, Dongpo Shi
Open Journal of Yangtze Oil and Gas (OJOGas) , 2017, DOI: 10.4236/ojogas.2017.23011
Abstract: ZG/ZH Mannich bases (acid corrosion inhibitors) were synthesized with benzaldehyde, 2-aminothiazole, acetophenone/cyclohexanone as raw materials, and selecting the appropriate proportion of reaction time, temperature and ratio of raw materials.The corrosion inhibition performance of two kinds of Mannich bases on N80 steel was investigated by means of mass loss method and electrochemical technique. The result of mass loss method showed that two kinds of inhibitors both had excellent effect on N80 steel in 15% hydro-chloric acid solution. Electrochemical technique showed that both ZG and ZH were a mainly anodic-controlling composite corrosion inhibitor, and their corrosion inhibition effect was further confirmed by AC impedance technique. The adsorption behavior between inhibitiors and the steel surface both abides by the Langmuir isotherm model.
The Theory of Quaternion Matrix Derivatives
Dongpo Xu,Danilo P. Mandic
Mathematics , 2014, DOI: 10.1109/TSP.2015.2399865
Abstract: A systematic theory is introduced for calculating the derivatives of quaternion matrix function with respect to quaternion matrix variables. The proposed methodology is equipped with the matrix product rule and chain rule and it is able to handle both analytic and nonanalytic functions. This corrects a flaw in the existing methods, that is, the incorrect use of the traditional product rule. In the framework introduced, the derivatives of quaternion matrix functions can be calculated directly without the differential of this function. Key results are summarized in tables. Several examples show how the quaternion matrix derivatives can be used as an important tool for solving problems related to signal processing.
Quaternion Gradient and Hessian
Dongpo Xu,Danilo P. Mandic
Computer Science , 2014, DOI: 10.1109/TNNLS.2015.2440473
Abstract: The optimization of real scalar functions of quaternion variables, such as the mean square error or array output power, underpins many practical applications. Solutions often require the calculation of the gradient and Hessian, however, real functions of quaternion variables are essentially non-analytic. To address this issue, we propose new definitions of quaternion gradient and Hessian, based on the novel generalized HR (GHR) calculus, thus making possible efficient derivation of optimization algorithms directly in the quaternion field, rather than transforming the problem to the real domain, as is current practice. In addition, unlike the existing quaternion gradients, the GHR calculus allows for the product and chain rule, and for a one-to-one correspondence of the proposed quaternion gradient and Hessian with their real counterparts. Properties of the quaternion gradient and Hessian relevant to numerical applications are elaborated, and the results illuminate the usefulness of the GHR calculus in greatly simplifying the derivation of the quaternion least mean squares, and in quaternion least square and Newton algorithm. The proposed gradient and Hessian are also shown to enable the same generic forms as the corresponding real- and complex-valued algorithms, further illustrating the advantages in algorithm design and evaluation.
Convergence of an Online Split-Complex Gradient Algorithm for Complex-Valued Neural Networks
Huisheng Zhang,Dongpo Xu,Zhiping Wang
Discrete Dynamics in Nature and Society , 2010, DOI: 10.1155/2010/829692
Abstract: The online gradient method has been widely used in training neural networks. We consider in this paper an online split-complex gradient algorithm for complex-valued neural networks. We choose an adaptive learning rate during the training procedure. Under certain conditions, by firstly showing the monotonicity of the error function, it is proved that the gradient of the error function tends to zero and the weight sequence tends to a fixed point. A numerical example is given to support the theoretical findings. 1. Introduction In recent years, neural networks have been widely used because of their outstanding capability of approximating nonlinear models. As an important search method in optimization theory, gradient algorithm has been applied in various engineering fields, such as adaptive control and recursive parametrical estimation [1–3]. Gradient algorithm is also a popular training method for neural networks (when used to train neural networks with hidden layers, gradient algorithm is also called BP algorithm) and can be done either in the online or in the batch mode [4]. In online training, weights are updated after the presentation of each training example, while in batch training, weights are not updated until all of the examples are inputted into the networks. As a result, batch gradient training algorithm is always used when the number of training samples is relatively small. However, in the case that a very large number of training samples are available, online gradient training algorithm is preferred. Conventional neural networks' parameters are usually real numbers for dealing with real-valued signals [5, 6]. In many applications, however, the inputs and outputs of a system are best described as complex-valued signals and processing is done in complex space. In order to solve the problem in complex domain, complex-valued neural networks (CVNNs) have been proposed in recent years [7–9], which are the extensions of the usual real-valued neural networks to complex numbers. Accordingly, there are two types of generalized gradient training algorithm for complex-valued neural networks: fully complex gradient algorithm [10–12] and split-complex gradient algorithm [13, 14]; both of which can be processed in online mode and batch mode. It has been pointed out that the split-complex gradient algorithm can avoid the problems resulting from the singular points [14]. Convergence is of primary importance for a training algorithm to be successfully used. There have been extensive research results concerning the convergence of gradient algorithm for
catena-Poly[[[aquapyridinezinc(II)]-μ2-3,3′-(p-phenylene)diacrylato] pyridine solvate]
Dongpo Su,Desheng Song,Zhiyong Fu
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810033167
Abstract: The title compound, {[Zn(C12H8O4)(C5H5N)(H2O)]·C5H5N}n, has been prepared by hydrothermal reaction. The ZnII atom is six-coordinated by four carboxylate O atoms of two p-phenylenediacrylate (ppda2 ) ligands, one N atom of a pyridine molecule and one O atom of a water molecule in a distorted octahedral environment. The carboxylate groups of the ppda2 anions are in a bridging–chelating mode, in which two O atoms chelate one Zn2+ ion. These connections result in an extended chain structure. Parallel packing of the chains forms a two-dimensional network with intermolecular edge-to-face interactions. Further linkages between the layers through O—H...O hydrogen-bonding interactions result in a three-dimensional supramolecular architecture with one-dimensional rectanglar channels.
Poly[di-μ2-chlorido(μ2-1,3-di-4-pyridylpropane-κ2N:N′)lead(II)]
Zhiyong Fu,Dongpo Su,Desheng Song
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809036150
Abstract: The title PbII coordination polymer, [PbCl2(C13H14N2)], was prepared by the hydrothermal reaction of PbCl2 with 4,4,-trimethylenedipyridine in a 1:1 ratio. It exhibits a two-dimensional layered structural motif consisting of PbCl2 chains and the flexible bridged 4,4′-trimethylenedipyridine ligand. The connections result in a cavity of about 4 × 15 .
Noise Simulation Analysis of a Variable Displacement External Gear Pump and Unloading Groove Optimization  [PDF]
Yongkang Zhou, Wenwu Li, Dongpo Yang
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1105030
Abstract:
The oil pump is an important part of vehicle engine, whose noise and vibration characteristics affect the engine performance significantly. The noises generat-ed by both the pressure and flow fluctuations are the main contributors to the oil pump noise. In this paper, noise analysis of an external gear pump is carried out by using the computational fluid dynamics (CFD) method and The Lighthill’s acoustic analogy (LAA) algorithm. The fluid pressure and velocity distributions of the flowfield are firstly calculated by using a CFD model. The noises generated by flowfield are simulated and their sound pressure spectra are obtained by using an LAA-based finite element model. By analyzing the phenomenon of oil trapping, the optimum design of unloading groove is put forward, and then the simulation analysis is carried out. According to the finite element model, the noise level of gear pump is reduced and the effect of noise reduction is achieved. The technique presented in this paper can be regarded as a useful tool for optimization design of gear pumps in vehicle engineering.
A Current-Mode DC-DC Buck Converter with High Stability and Fast Dynamic Response
Chen Dongpo,He Lenian,Yan Xiaolang,
Chen Dongpo
,He Lenian,Yan Xiaolang

半导体学报 , 2006,
Abstract: 提出了一种高稳定性的电流型DC-DC转换器.首先应用一种新型的电流型转换器的模型推导了控制环路的增益表达式,在分析其环路增益的基础上,提出了一种新颖的控制环路频率补偿的方法,从而使转换器的稳定性不受负载电流和电源电压变化的影响.其次应用这种新的频率补偿方法,使用0.5μm-CMOS工艺设计了一种电流模式的降压型转换器.仿真结果表明,该稳压器具有高度的稳定特性,其稳定性与负载和电源电压无关.并且由于这种新的频率补偿为环路提供了极高的带宽,所以该转换器具有优异的动态响应.其提供的全负载瞬态响应的建立时间小于5μs,过冲电压小于30mV.
Regional Δ14C patterns and fossil fuel derived CO2 distribution in the Beijing area using annual plants
XianTing Xi,XingFang Ding,DongPo Fu,LiPing Zhou,KeXin Liu
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4453-8
Abstract: The level of atmospheric Δ14C and the fossil fuel derived CO2 concentration in the Beijing area from May to September, 2009, were systematically analyzed based on radiocarbon (14C) measurements of annual plants by accelerator mass spectrometry (AMS). The results show that the maximum Δ14C in Beijing was 29.6‰±2.2‰, and the minimum was 28.2‰±2.5‰, with a trend of decreasing Δ14C from the outer suburbs to inner suburbs to the urban center. This trend correlates well with increases in fossil fuel derived CO2 caused by human activities such as population density, industrial emissions and traffic, with lower values of atmospheric Δ14C associated with more intensive human activities. The fossil fuel derived CO2 concentrations from May to September, 2009, ranged from 3.9±1.0 ppm to 25.4±1.0 ppm. It was calculated that each additional 1 ppm of CO2 from fossil fuels depleted the atmospheric Δ14C by approximately 2.70‰. This study suggests that 14C measurements of annual plants by AMS provide an effective method to rapidly trace fossil fuel derived CO2.
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