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International Conference on Materials and Products Manufacturing Technology (ICMPMT 2011)

作者： Kuang Yuchun Wu Yongxing Yan Jinlin Wang Qin SW Petr Univ Chengdu 610500 Peoples R China

ISBN: (纸本)9783037852491

This paper analyzes several important issues on the drill string system dynamics model and its numerical algorithm. Firstly, it introduces the commonly used numerical methods and contact algorithms, and analyzes the advantages and disadvantages of each method in detail. Secondly, it analyzes the application of explicit and implicit methods for the current stress iteration algorithm, and specifies the implicit algorithm should be used in the research of drill string system dynamics. This paper focuses on the research of damping model and bit-rock interaction model, solves the damping effect based on the theory of ocean wave mechanics, and establishes a simplified bit-rock interaction model. Finally, a virtual numerical simulation example shows that the method used in this paper can analyze the dynamic of drill string used in the 1,000-meter complex well bore. The research result of this paper has certain guiding meanings on the analysis of working behavior of extra-long pipe string in the complex well bore by using numerical methods in the oil field.

关键词： drill string dynamics numerical simulation iteration algorithm contact algorithm damping model bit-rock interaction

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A Novel Joint Source and Relay MMSE Precoding algorithm in Non-Regenerative Dual Hop Relay Networks

A Novel Joint Source and Relay MMSE Precoding Algorithm in N...

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2011 World Congress on Engineering and Technology(CET 2011)

作者： Hongfa Chu 1 Jun LI 1,2,Dan Yu 1,Zhiqiang He 1,Weiling Wu 1 1 Key Laboratory of Universal Wireless Communication,Ministry of Education Beijing University of Posts and Telecommunications (BUPT) Beijing 100876,China,P.R. 2 School of Electronic Information and Control Engineering Shandong Polytechnic University (SPU) Jinan 250353,China,P.R.

A novel joint precoding optimization algorithm is proposed in dual hop multiple input multiple output (MIMO) relay communication systems with full channel state information (CSI),generally joint optimization always use iteration algorithm and combines precoding for source and relay with detection for destination node *** to the consistency for precoding and detection for interference cancelling,in this paper,joint optimization only consider the precoding algorithm for source and relay node,and leave out the detection algorithm for destination node,therefore it reduces the iteration calculation complexity and easy for implementation for destination node,and from simulation results the performance is only a little ***,when complexity and performance are considered,this algorithm reaches a better compromise.

关键词： MIMO relay channel state information precoding joint optimization iteration algorithm

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A Trust Evaluation Model using Controlled Markov Process for MANET

A Trust Evaluation Model using Controlled Markov Process for...

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6th Annual IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)/STMWC/NASSUE/CMPA/VECON/AWSAN/AWSAN

作者： Ouyang, Kevin Xuhua Vaidya, Binod Makrakis, Dimitrios Univ Ottawa Sch Informat Technol & Engn Ottawa ON K1N 6N5 Canada

ISBN: (纸本)9781424477425

A distributed trust evaluation model is presented for MANETs by which uncertainties of trust are transformed into probability vectors giving the probability distribution of trust levels. The system evolves over time as a finite-state Markov process with variant transition matrixes. We attempt to predict the trustworthiness values of entities that are determined by their inherent error patterns. The Markov process is associated to a Bonus-Malus System and controlled by the estimated error patterns of individual entities involved. As well, an iteration algorithm is designed to prevent inaccurate predictions for trust values because of the properties of Markov process. The simulation results demonstrate that our model is able to predict local trust successfully for entities in MANETs by estimating their actual error patterns accurately.

关键词： Bonus-Malus system Manet Markov process Markov processes ad hoc networks distributed trust evaluation model iteration algorithm iterative methods matrix algebra mobile ad hoc network mobile radio probability probability distribution transition matrixes

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Voltage Sag Assessment Based on the Interval Characteristic of Customer Satisfaction

Voltage Sag Assessment Based on the Interval Characteristic ...

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Asia-Pacific Power and Energy Engineering Conference (APPEEC)

作者： Du Xin-wei Huang Shan Wang Ying Xiao Xian-yong Sichuan Elect Power Corp Sichuan Elect Power Test & Res Inst Chengdu Peoples R China Smart Grid Key Lab Sichuan Prov Chengdu Peoples R China Sichuan Univ Coll Elect Engn & Informat Technol Chengdu 610065 Sichuan Peoples R China

ISBN: (纸本)9781424448135

An analytical voltage sag assessment method is proposed considering the interval characteristic of customer satisfaction degree. Based on the relationship between fault line length and voltage amplitude, the critical fault position can be determined by iterative algorithm and the customer un-satisfaction area in the power supply system is determined also. Due to the interval characteristic of customer satisfaction degree, the frequency of voltage sags at given buss can be assessed by the un-satisfaction area. The proposed method has been applied to a five-buss system and IEEE 30-buss RTS and compared with existing methods. The results show that the new method is credible and correct and with practical foreground.

关键词： voltage sag assessment customer satisfaction degree interval characteristic iteration algorithm

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Characterisation, analysis and injection of two-tone third-order intermodulation products in an amplifier

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IET MICROWAVES ANTENNAS & PROPAGATION 2009年第3期3卷 443-455页

作者： Xiao, M. Gardner, P. Univ Birmingham Elect Elect & Comp Engn Dept Birmingham B15 2TT W Midlands England

A new mathematical description of the relationship between injected and output third-order intermodulation (IM3), to predict the injection signals required for predistortion correction of a power amplifier (PA), without manual optimisation is presented. A new concept of interactions and an iteration algorithm are also presented in order to improve this technique. The method is demonstrated with a commercial 2 GHz PA driven hard in a two-tone test with a range of input power and tone-spacing. The measurement results show that IM3 in a two-tone test can be suppressed by at least 60 dB, when the interactions between the upper and lower IM3 generation and the correction process are properly accounted for. The technique can deal with memory effects by cancelling unequal upper and lower sidebands.

关键词： iterative methods frequency 2 GHz Interpolation and function approximation (numerical analysis) Modulation and coding methods Amplifiers power amplifiers mathematical description power amplifier intermodulation injected and output third-order intermodulation iteration algorithm predistortion correction

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A new method for parameter estimation based on temporal-spatial extrapolation

A new method for parameter estimation based on temporal-spat...

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2009 IET International Radar Conference

作者： Xueya Yang Baixiao Chen Shuyuan Chao National Laboratory for Radar Signal Processing Xidian University Xi'an Shanxi China

ISBN: (纸本)9781849190107

An iterative nonparametric algorithm for estimating the frequencies and direction-of-arrivals (DOAs) of signals impinging on the passive array is proposed in this paper. The procedure includes two parts, frequency estimation by extrapolating the series in time domain and angle estimation by extrapolating the series in space domain. The extrapolation is carried out by using its sparse discrete Fourier transform (DFT), to get which, the deductions of minimization problem based on l 2 -norm constraint and linear constraint using the iteration algorithm are presented. It is shown that the algorithm offers increased resolution, significantly reduced sidelobes and much lower computational complexity. Some numerical simulation and real data processing results are presented to verify the effectiveness of the method.

关键词： Temporal-spatial extrapolation iteration algorithm Frequency DOA

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Specmurt analysis of polyphonic music signals

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IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2008年第3期16卷 639-650页

作者： Saito, Shoichiro Kameoka, Hirokazu Takahashi, Keigo Nishimoto, Takuya Sagayama, Shigeki Univ Tokyo Grad Sch Informat Sci & Technol Tokyo 1138656 Japan

This paper introduces a new music signal processing method to extract multiple fundamental frequencies, which we call specmurt analysis. In contrast with cepstrum which is the inverse Fourier transform of log-scaled power spectrum with linear frequency, specmurt is defined as the inverse Fourier transform of linear power spectrum with log-scaled frequency. Assuming that all tones in a polyphonic sound have a common harmonic pattern, the sound spectrum can be regarded as a sum of linearly stretched common harmonic structures along frequency. In the log-frequency domain, it is formulated as the convolution of a common harmonic structure and the distribution density of the fundamental frequencies of multiple, tones. The fundamental frequency distribution can be found by deconvolving the observed spectrum with the assumed common harmonic structure, where the common harmonic structure is given heuristically or quasi-optimized with an iterative algorithm. The efficiency of specmurt analysis is experimentally demonstrated through generation of a piano-roll-like display from a polyphonic music signal and automatic sound-to-MIDI conversion. Multipitch estimation accuracy is evaluated over several polyphonic music signals and compared with manually annotated MIDI data.

关键词： inverse filtering iteration algorithm multipitch analysis pitch visualization polyphonic music signals

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Convergence theorems of common fixed points for a finite family of Lipschitz pseudocontractions in Banach spaces

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NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS 2008年第10期68卷 2977-2983页

作者： Zhou, Haiyun N China Elect Power Univ Inst Nonlinear Anal Baoding 071003 Peoples R China

In this paper, we continue to study weak convergence problems for the implicit iteration process for a finite family of Lipschitzian continous pseudocontractions in general Banach spaces. The results presented in this paper improve and extend the corresponding ones of Xu and Ori [H.K. Xu, R.G. Ori, An implicit iteration process for nonexpansive mapphigs, Number. Funct. Anal. Optim. 22 (2001) 767-773], Osilike [M.O. Osilike, Implicit iteration process for common fixed points of a finite family of strictly pseudocontractive maps, J. Math. Anal. Appl. 294 (2004) 73-81], Chen et al. [R. Chen, ***, H.Y. Zhou, Convergence theorems for implicit iteration process for a finite family of continous pseudocontractive mappings, J. Math. Anal. Appl. 314 (2006) 701-709] and others. (C) 2007 Elsevier Ltd. All rights reserved.

关键词： Lipschitz pseudocontraction iteration algorithm convergence theorem

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Convergence theorems of fixed points for Lipschitz pseudo-contractions in Hilbert spaces

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JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS 2008年第1期343卷 546-556页

作者： Zhou, Haiyun N China Elect Power Univ Inst Nonlinear Anal Baoding 071003 Peoples R China

Let C be a closed convex subset of a real Hilbert space H and assume that T is a k-strict pseudo-contraction on C. Consider Mann's iteration algorithm given by for all x(0) is an element of C, x(n+1) = alpha(n)x(n) + (1 - alpha(n))Tx(n), n >= 0. It is proved that if the control sequence {alpha(n)} is chosen so that k < alpha(n) < 1 and Sigma(infinity)(n=0)(alpha(n) - k) (1 - alpha(n)) = infinity, then lim(n ->infinity) vertical bar vertical bar x(n) - Tx(n) vertical bar vertical bar = d(0, ($$$) over barR(A)), where A = I - T and d(0,D) denotes the distance between the origin and the subset set D of H. As a consequence of this result, we prove that if T has a fixed point in C, then {x(n)} converges weakly to a fixed point of T. Also, we extend a result due to Reich to kappa-strict pseudo-contractions in the Hilbert space setting. Further, by virtue of hybridization projections, we establish a strong convergence theorem for Lipschitz pseudo-contractions. The results presented in this paper improve or extend the corresponding results of Browder and Petryshyn [F.E. Browder, W.V. Petryshyn, Construction of fixed points of nonlinear mappings in Hilbert spaces, J. Math. Anal. Appl. 20 (1967) 197-228], Rhoades [B.E. Rhoades, Fixed point iterations using infinite matrices, Trans. Amer. Math. Soc. 196 (1974) 162-176] and of Marino and Xu [G. Marino, H.-K. Xu, Weak and strong convergence theorems for strict pseudo-contractions in Hilbert spaces, J. Math. Anal. Appl. 329 (1) (2007) 336-346]. (C) 2008 Elsevier Inc. All rights reserved.

关键词： Lipschitz pseudo-contraction iteration algorithm convergence theorem

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A Vector Matrix Iterative Self-Organizing Assistant Clustering algorithm of XML Document

A Vector Matrix Iterative Self-Organizing Assistant Clusteri...

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9th International Conference for Young Computer Scientists

作者： Liu, Bo Yang, LuMing Deng, Yunlong Cent S Univ Coll Informat Sci & Engn Changsha 410083 Peoples R China IIunan Agr Univ Informat Sci & Technol Coll Changsha 410083 Peoples R China Cent S Univ Xiangya Hosp 3 Changsha 410013 Peoples R China

ISBN: (纸本)9781424441983

To improve the clustering quality of massive extensible mark-up language (XML) document clustering, this paper proposes a vector matrix iterative self-organizing assistant clustering algorithm of XML document(VMISACAX). The algorithm bases on the XML key, and transforms XML document into vector matrix, then carries out the optimizations of canceling, dissociating and uniting etc. In order to improve the convergence of the algorithm, a assistant strategy is imported to shorten the algorithm time under settling for clustering, to obtain best result of clustering by XML key's weights, but it doesn't always obtain the maximum distance's target of matrix vector clustering. Contrasted with other vector clustering algorithms, a series of emulation experiments show that this algorithm has proper the effectiveness and feasibility.

关键词： XML key Vector Matrix Weight Clustering iteration algorithm

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