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A New User Segmentation Model for E-Government

JOURNAL OF ELECTRONIC COMMERCE IN ORGANIZATIONS 2013年第2期11卷 1-11页

作者： Tang, Ran Zhang, Zhenji Guan, Xiaolan Wang, Lida Beijing Jiaotong Univ Beijing Peoples R China Beijing Inst Graph Commun Beijing Peoples R China China Software Testing Ctr Beijing Peoples R China

E-government in China has entered the development stage of personalized services, and user segmentation has become an urgent demand. On the basis of systematic interpretation of e-government development stages, in this article, the authors introduce CRM and customer segmentation concept into e-government areas, construct e-government user segmentation model, and obtain user segmentation results by empirical analysis. Comparing with existing segmentation methods based on experience, because of the introduction of customer segmentation concept and K-means algorithm, e-government user segmentation model presented makes segmentation more scientific and reasonable and can adjust dynamically as the user needs change, continuously improving.

关键词： cluster algorithm Customer Relationship Management (CRM) Customer Segmentation E-Government User K-Means algorithm

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A computerized image analysis system for quantitative analysis of cells in histological brain sections

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JOURNAL OF NEUROSCIENCE METHODS 2003年第1-2期125卷 33-43页

作者： Benali, A Leefken, I Eysel, UT Weiler, E Ruhr Univ Bochum Inst Neuroinformat D-44780 Bochum Germany Ruhr Univ Bochum Inst Physiol Abt Neurophysiol D-44780 Bochum Germany

We propose a reliable method for automatic counting of cells in brain sections labeled with different antibodies (against NeuN, parvalbumin, GABA and c-Fos) and in Nissi-staining. Images of stained sections are converted to binary images by thresholding. clusters of 'ON pixels' (value of 1) corresponding to cell bodies are selected based on size. The parameters of the algorithm (intensity range and cluster-size) are adjusted for different methods of staining according to expert knowledge. The automatic cell counting method (ACCM) provides correct counting results, as demonstrated by a comparison of computational results with counts gained by human experimenters and with a commercially available image analysis system. On the basis of ACCM counts, small and perhaps physiologically relevant differences in the number of labeled cells can be revealed, as demonstrated here for the GABAergic system following electrical stimulation. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： binarization cell counting cluster algorithm electrical stimulation GABA immunohistochemistry neuron spatial distribution

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The three-state square-lattice Potts antiferromagnet at zero temperature

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JOURNAL OF STATISTICAL PHYSICS 1998年第5-6期92卷 729-753页

作者： Salas, J Sokal, AD Univ Zaragoza Fac Ciencias Dept Fis Mat Condensada E-50009 Zaragoza Spain Univ Zaragoza Fac Ciencias Dept Fis Teor E-50009 Zaragoza Spain NYU Dept Phys New York NY 10003 USA

We study the 3-state square-lattice Potts antiferromagnet at zero temperature by a Monte Carlo simulation using the Wang-Swendsen-Kotecky cluster algorithm, on lattices up to 1024 x 1024. We confirm the critical expon... 详细信息

关键词： antiferromagnetic Potts model critical ground state height representation critical exponent Monte Carlo Wang-Swendsen-Kotecky algorithm cluster algorithm

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Application of new Monte Carlo algorithms to random spin systems

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COMPUTER PHYSICS COMMUNICATIONS 2002年第1期146卷 63-68页

作者： Okabe, Y Tomita, Y Yamaguchi, C Tokyo Metropolitan Univ Dept Phys Hachioji Tokyo 1920397 Japan

We explain the idea of the probability-changing cluster (PCC) algorithm, which is an extended version of the Swendsen-Wang algorithm. With this algorithm, we can tune the critical point automatically. We show the effectiveness of the PCC algorithm for the case of the three-dimensional (3D) Ising model. We also apply this new algorithm to the study of the 3D diluted Ising model. Since we tune the critical point of each random sample automatically with the PCC algorithm, we can investigate the sample-dependent critical temperature and the sample average of physical quantities at each critical temperature, systematically. We have also applied another newly proposed algorithm, the Wang-Landau algorithm, to the study of the spin glass problem. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： cluster algorithm Ising model random spin systems

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Dynamic critical behavior of the Swendsen-Wang algorithm for the three-dimensional Ising model

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NUCLEAR PHYSICS B 2004年第3期691卷 259-291页

作者： Ossola, G Sokal, AD NYU Dept Phys New York NY 10003 USA

We have performed a high-precision Monte Carlo study of the dynamic critical behavior of the Swendsen-Wang algorithm for the three-dimensional Ising model at the critical point. For the dynamic critical exponents associated to the integrated autocorrelation times of the "energy-like" observables, we find z(int,N) = z(int,epsilon) = z(int,epsilon')= 0.459 +/- 0.005 +/- 0.025, where the first error bar represents statistical error (68% confidence interval) and the second error bar represents possible systematic error due to corrections to scaling (68% subjective confidence interval). For the "susceptibility-like" observables, we find z(int,M2) = z(int,S2) = 0.443 +/- 0.005 +/- 0.030. For the dynamic critical exponent associated to the exponential autocorrelation time, we find z(exp) approximate to 0.481. Our data are consistent with the Coddington-Baillie conjecture z(SW) = beta/v approximate to 0.5183, especially if it is interpreted as referring to z(exp). (C) 2004 Elsevier B.V. All rights reserved.

关键词： Ising model Potts model Swendsen-Wang algorithm cluster algorithm Monte Carlo autocorrelation time dynamic critical exponent

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Increase in heterogeneity of biceps brachii activation during isometric submaximal fatiguing contractions: a multichannel surface EMG study

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JOURNAL OF NEUROPHYSIOLOGY 2014年第5期111卷 984-990页

作者： Staudenmann, Didier van Dieen, Jaap H. Stegeman, Dick F. Enoka, Roger M. Univ Fribourg Dept Med Fac Sci CH-1700 Fribourg Switzerland Vrije Univ Amsterdam MOVE Res Inst Amsterdam Fac Human Movement Sci Amsterdam Netherlands King Abdulaziz Univ Jeddah 21413 Saudi Arabia Radboud Univ Nijmegen Donders Inst Brain Cognit & Behav Dept Neurol Clin Neurophysiol Med Ctr NL-6525 ED Nijmegen Netherlands Univ Colorado Dept Integrat Physiol Boulder CO 80309 USA

The effects of fatigue emerge from the beginning of sustained submaximal contractions, as shown by an increase in the amplitude of the surface electromyogram (EMG). The increase in EMG amplitude is attributed to an augmentation of the excitatory drive to the motor neuron pool that, more importantly than increasing discharge rates, recruits additional motor units for the contraction. The aim of this study was to determine whether the spatiotemporal distribution of biceps brachii (BB) activity becomes more or less heterogeneous during a fatiguing isometric contraction sustained at a submaximal target force. Multiple electrodes were attached over the entire BB muscle, and principal component analysis (PCA) was used to extract the representative information from multiple monopolar EMG channels. The development of heterogeneity during the fatiguing contraction was quantified by applying a cluster algorithm on the PCA-processed EMG amplitudes. As shown previously, the overall EMG amplitude increased during the sustained contraction, whereas there was no change in coactivation of triceps brachii. However, EMG amplitude did not increase in all channels and even decreased in some. The change in spatial distribution of muscle activity varied across subjects. As found in other studies, the spatial distribution of EMG activity changed during the sustained contraction, but the grouping and size of the clusters did not change. This study showed for the first time that muscle activation became more heterogeneous during a sustained contraction, presumably due to a decrease in the strength of common inputs with the recruitment of additional motor units.

关键词： electromyography monopolar signals muscle fatigue principal component analysis cluster algorithm motor control

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Consensus clustering and functional interpretation of gene-expression data

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GENOME BIOLOGY 2004年第11期5卷 1-16页

作者： Swift, S Tucker, A Vinciotti, V Martin, N Orengo, C Liu, XH Kellam, P UCL Windeyer Inst Dept Infect Virus Genom & Bioinformat Grp London W1T 4JF England Brunel Univ Dept Informat Syst & Comp Uxbridge UB8 3PH Middx England Univ London Birkbeck Coll Sch Comp Sci & Informat Syst London WC1E 7HX England UCL Dept Biochem & Mol Biol London WC1E 6BT England

Microarray analysis using clustering algorithms can suffer from lack of inter-method consistency in assigning related gene-expression profiles to clusters. Obtaining a consensus set of clusters from a number of clustering methods should improve confidence in gene-expression analysis. Here we introduce consensus clustering, which provides such an advantage. When coupled with a statistically based gene functional analysis, our method allowed the identification of novel genes regulated by NFkappaB and the unfolded protein response in certain B-cell lymphomas.

关键词： cluster algorithm Simulated Annealing Synthetic Dataset Consensus cluster Robust cluster

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CPA: A cluster-Based Packet Acknowledgement Approach in WSNs

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JOURNAL OF INTERNET TECHNOLOGY 2014年第2期15卷 203-214页

作者： Sun, Yun-Lei Qiao, Xiu-Quan Cheng, Bo Xue, Si-Da Chen, Jun-Liang Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing Peoples R China China Univ Petr State Key Lab Networking & Switching Technol Beijing Peoples R China

In wireless sensor network, repairing packet loss lead to increasing of the network load and substantial energy consumption. In order to reduce the network load, most of transport protocols employ a Cumulative Acknowledgment (CACK) policy for received packets. In this paper, we propose a cluster-based Packet Acknowledgement (CPA) approach that naturally reduces more ACKs than traditional approaches of cumulating multi-packets of multi-nodes. A distributed greedy clustering algorithm is employed to form clusters with the minimum number. Different strategies are used to reduce the amount of packet ACKs in intra-cluster and inter-cluster respectively. And a scalable Bloom Filter is used to fix the length of the CACK, which can effectively save the storage. We also discuss a guarantee condition for the reduction of packet ACK path length. Our simulation results show that the CPA approach effectively increases the packet delivery ratio, and also reduces both the average end-to-end delay and the total length of ACKs, which thus decreases the network load.

关键词： Wireless sensor network Transport protocol cluster algorithm Bloom filter Packet delivery

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cluster Monte Carlo study of multicomponent fluids of the Stillinger-Helfand and Widom-Rowlinson type

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Physical Review E 2000年第2期62卷 2226-2226页

作者： Rongfeng Sun Harvey Gould J. Machta L. W. Chayes Department of Mathematics University of California Los Angeles California 90095-1555

Phase transitions of fluid mixtures of the type introduced by Stillinger and Helfand are studied using a continuum version of the invaded cluster algorithm. Particles of the same species do not interact, but particles of different types interact with each other via a repulsive potential. Examples of interactions include the Gaussian molecule potential and a repulsive step potential. Accurate values of the critical density, fugacity, and magnetic exponent are found in two and three dimensions for the two-species model. The effect of varying the number of species and of introducing quenched impurities is also investigated. In all the cases studied, mixtures of q species are found to have properties similar to q-state Potts models.

关键词： .quenched repulsive interact fugacity critical density Potts models invaded WIDOM-ROWLINSON cluster Monte Carlo cluster algorithm same species molecule potential

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Monte Carlo simulations of doped, diluted magnetic semiconductors - A system with two length scales

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INTERNATIONAL JOURNAL OF MODERN PHYSICS C 1999年第8期10卷 1459-1470页

作者： Bhatt, RN Wan, X Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

We describe a Monte Carlo simulation study of the magnetic phase diagram of diluted magnetic semiconductors doped with shallow impurities in the low concentration regime. We show that because of a wide distribution of interaction strengths, the system exhibits strong quantum effects in the magnetically ordered phase. A discrete spin model, found to closely approximate the quantum system, shows long relaxation times, and the need for specialized cluster algorithms for updating spin configurations. Results for a representative system are presented.

关键词： Monte Carlo simulation diluted magnetic semiconductors shallow impurity phase transition cluster algorithm

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