This paper proposes a new method for finding principal curves from complex distribution dataset. Motivated by solving the problem, which is that existing methods did not perform well on finding principal curve in comp...
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ISBN:
(数字)9783642162480
ISBN:
(纸本)9783642162473
This paper proposes a new method for finding principal curves from complex distribution dataset. Motivated by solving the problem, which is that existing methods did not perform well on finding principal curve in complex distribution dataset with high curvature, high dispersion and self-intersecting, such as spiral-shaped curves, Firstly, rudimentary principal graph of data set is created based on the thinning algorithm, and then the contiguous vertices are merged. Finally the fitting-and-smoothing step introduced by Kegl is improved to optimize the principal graph, and Kegl's restructuring step is used to rectify imperfections of principal graph. Experimental results indicate the effectiveness of the proposed method on finding principal curves in complex distribution dataset.
In recent years, the Bag-of-Words (BoW) model has been widely used in most state-of-the-art large-scale image re-trieval systems. However, the standard BoW based systems suffer from low discriminative power of local f...
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The password pattern has become a widely used mobile authentication method. However, there are still some potential security problems since the passwords are easy to be cracked by some malicious software. An important...
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Learned image compression approaches have shown great potential with promising results. However, according to the commonly used measurement methods, there still lies a performance gap between learned compression metho...
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Resting state functional magnetic resonance imaging (rsfMRI) is a relatively new and an powerful method for evaluating regional interactions that occur when a participant is not performing an explicit task. Because of...
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Credit card fraud problem is very common in recent years. It not only causes economic loss to people, but also causes trust crisis to enterprises. Due to the imbalance of data, fraud detection has always been tricky. ...
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Passive sensor networks can achieve accurate detection of target under complex environment. In order to adapt to different communication demands of sensor networks in different environments, this paper designed and im...
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In this paper we propose a novel Frequency Selective SRS (FS-SRS) scheme to improve the quality of CSI. According to the CQIs (channel quality indications), which are periodically reported by each user, and the bandwi...
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ISBN:
(纸本)9781479935130
In this paper we propose a novel Frequency Selective SRS (FS-SRS) scheme to improve the quality of CSI. According to the CQIs (channel quality indications), which are periodically reported by each user, and the bandwidth requirement of each user, BSs dynamically schedule each user to send SRSs only on the requisite bandwidth with best CQIs instead of on full bandwidth or on specified sub-bandwidth as in the current LTE TDD systems. Simulation results show that the proposed FS-SRS scheme outperforms the current schemes in estimation accuracy for various frequency-selective and/or time-selective fading channels. In addition, the proposed FS-SRS scheme offers unique advantages over the current schemes. Firstly, it is robust to frequency selective channels. Secondly, it is hardly impacted by timing offset. Thirdly, it is adaptive to the change of the underlying scheduler. Fourthly, it can increase SRS capacity. Finally, it can be extended to multi-user MIMO (multiple-input multiple-output) systems, called extended FS-SRS scheme. Moreover, the proposed schemes are applicable to the uplink SRS design in LTE-Advanced systems.
The asymptotic signal bandwidth of various kinds of large-scale asynchronous Time Hopping Impulse Radio Ultra-Wide Band (TH-IR UWB) communication networks such that multiple access interference can be negligible with ...
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In order to improve fault forecasting model accuracy of back propagation neural network (BPNN), an improved prediction method of optimized BPNN based on Multilevel Genetic Algorithm (MGA) was proposed. We design new c...
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