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Jiao B.,Luoyang Electronic Equipment Test Center
Computer Communications | Year: 2016

The normalized Laplacian spectrum (NLS) is a powerful tool for comparing graphs with different sizes. Recently, we showed that two NLS features, namely the weighted spectral distribution (WSD) and the multiplicity of the eigenvalue 1 (ME1), are particularly relevant to the Internet topology at the inter-domain level. In this paper, we examine the physical meaning of the two metrics for the Internet. We show that the WSD reflects the transformation from single-homed nodes to multi-homed nodes for better fault-tolerance and that the ME1 quantifies the initial star-based structure associated with node classification, both of which are critical to the robustness of the Internet structure. We then investigate the relation between the metrics and graph perturbations (i.e., small changes in a graph). We show that these two NLS metrics can be a good choice for study on the Internet optimization. Our work reveals novel insights into the Internet structure and provides useful knowledge for statistical analysis on complex networks. © 2015 Elsevier B.V.All rights reserved. Source

Zhang W.-A.,Luoyang Electronic Equipment Test Center | Chen B.-L.,Changchun University of Science and Technology
Hongwai Yu Haomibo Xuebao/Journal of Infrared and Millimeter Waves | Year: 2014

We derived object temperature from emissivity spectrum using the emissivity normalized method and discussed the feasibility of recognizing objects using ground object thermal infrared spectra. The results show that the emissivity normalized method based on thermal multispectral data can invert object temperature and emissivity spectrum efficiently. It means that inversion of emissivity spectra can be effectively applied in feature recognition, especially for different soil properties. Source

Xiaojun H.,State Key Laboratory of Complex Electromagnetic | Jinghai Y.,Luoyang Electronic Equipment Test Center
Proceedings - 2014 International Conference on Information Science, Electronics and Electrical Engineering, ISEEE 2014 | Year: 2014

Because of multipath transmission, the quality of communication has been affected greatly. In this paper, based on the time reversal technique, iterative arithmetic for multipath signal transmission is proposed. By the time reversal iterative technique, the influence of multipath can be reduced greatly, and S/N can be also improved. By performing the injecting test based on the test bed for multipath communications, this arithmetic is proved to be effective. © 2014 IEEE. Source

Huang H.-C.,Chung Hua University | Yang X.,Luoyang Electronic Equipment Test Center
Mathematical Problems in Engineering | Year: 2014

A hesitant fuzzy linguistic term set (HFLTS), allowing experts using several possible linguistic terms to assess a qualitative linguistic variable, is very useful to express people's hesitancy in practical decision-making problems. Up to now, a little research has been done on the comparison and distance measure of HFLTSs. In this paper, we present a comparison method for HFLTSs based on pairwise comparisons of each linguistic term in the two HFLTSs. Then, a distance measure method based on the pairwise comparison matrix of HFLTSs is proposed, and we prove that this distance is equal to the distance of the average values of HFLTSs, which makes the distance measure much more simple. Finally, the pairwise comparison and distance measure methods are utilized to develop two multicriteria decision-making approaches under hesitant fuzzy linguistic environments. The results analysis shows that our methods in this paper are more reasonable. © 2014 Han-Chen Huang and Xiaojun Yang. Source

Huang H.-C.,Chung Hua University | Yang X.,Luoyang Electronic Equipment Test Center
International Journal of Uncertainty, Fuzziness and Knowlege-Based Systems | Year: 2016

Since Zadeh introduced fuzzy sets, a lot of extensions of this concept have been proposed, such as type-2 fuzzy sets, nonstationary fuzzy sets, and cloud models, to represent higher levels of uncertainty. This paper provides a comparative investigation of type-2 fuzzy sets, nonstationary fuzzy sets, and cloud models. Type-2 fuzzy sets study the fuzziness of the membership function (MF) using primary MF and secondary MF based on analytic mathematical methods; nonstationary fuzzy sets study the randomness of the MF using primary MF and variation function based on type-1 fuzzy sets theory; cloud models study the randomness of the distribution of samples in the universe and generate random membership grades (MGs) using two random variables based on probability and statistic mathematical methods. They all concentrate on dealing with the uncertainty of the MF or the MG which type-1 fuzzy sets do not consider, and thus have many similarities. Moreover, we find out that, the same qualitative concept "moderate amount" can be represented by an interval type-2 fuzzy set, a nonstationary fuzzy set or a normal cloud model, respectively. Then, we propose a unified mathematical expression for the interval type-2 fuzzy set, nonstationary fuzzy set and normal cloud model. On the other hand, we also find out that, the theory fundament and underlying motivations of these models are quite different. Therefore, We summarize detailed comparisons of distinctive properties of type-2 fuzzy sets, nonstationary fuzzy sets, and cloud models. Further, we study their diverse characteristics of distributions of MGs across vertical slices. The comparative investigation shows that these models are complementary to describe the uncertainty from different points of view. Thus, this paper provides a fundamental contribution and makes a basic reference for knowledge representation and other applications with uncertainty. © 2016 World Scientific Publishing Company. Source

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