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Wu J.,Science and Technology on Electronic Information Control Laboratory
2015 IEEE International Conference on Information and Automation, ICIA 2015 - In conjunction with 2015 IEEE International Conference on Automation and Logistics | Year: 2015

The detection of early manmade fire carries profound meaning in warning systems to prevent fire-related terrorist attacks. Despite a large number of work on fire detection in the computer vision literature, there is no specific method for early stage manmade fire detection, our best knowledge. Compared to traditional fire detection, there is less information on early stage man-made fire for detection, because of the small scale and short appearance. In this paper, an algorithm is proposed by combining the characteristics of fire with human activity. Experimental comparisons have shown that our algorithm has outperformed the state-of- The-art fire detection methods, as the initial combustion is considered. © 2015 IEEE.

Wang J.,Beijing Jiaotong University | Zhang W.,Science and Technology on Electronic Information Control Laboratory | Liu W.,University of Sheffield
Multidimensional Systems and Signal Processing | Year: 2016

An enhanced eigenspace-based beamformer (ESB) derived using the minimum sensitivity criterion is proposed with significantly improved robustness against steering vector errors. The sensitivity function is defined as the squared norm of the appropriately scaled weight vector and since the sensitivity function of an array to perturbations becomes very large in the presence of steering vector errors, it can be used to find the best projection for the ESB, irrespective of the distribution of additive noises. As demonstrated by simulation results, the proposed method has a better performance than the classic ESBs and the previously proposed uncertainty set based approach. © 2016 Springer Science+Business Media New York

Wang P.,University of Electronic Science and Technology of China | Wang P.,Chongqing Three Gorges University | Wen G.,University of Electronic Science and Technology of China | Zhang H.,Science and Technology on Electronic Information Control Laboratory | Sun Y.,University of Electronic Science and Technology of China
IEEE Transactions on Antennas and Propagation | Year: 2013

The radiation characteristics of a wideband conformal end-fire antenna array mounted on a large conducting cylinder are investigated in this communication. By employing balanced Vivaldi antenna element, the antenna array has ultra-wide bandwidth, low cross-polarization levels, and wide 3 dB beam-width. It is shown that using a larger antenna height, shorter distance away from the edge of a hollow conducting cylinder, and bigger slant angle of antenna element leads to better end-fire radiation performances. Measured radiation patterns are compared with simulated values and a good agreement is observed. A radome-antenna system is also studied and it is found that the antenna has a larger beam-pointing angle in the H-plane owing to the electromagnetic waves reflected from a dielectric radome surface, while retaining its symmetric pattern in the E-plane. These findings may provide useful insights and guidelines for the design of large radome-antenna systems mounted a cylindrical platform. © 1963-2012 IEEE.

Zhang X.Y.,Ecole Centrale Marseille | Zhang X.Y.,Science and Technology on Electronic Information Control Laboratory | Tortel H.,Ecole Centrale Marseille | Litman A.,Ecole Centrale Marseille | Geffrin J.-M.,Ecole Centrale Marseille
Inverse Problems | Year: 2012

In this work, we present an extension of the classical DORT method for time-harmonic inverse medium scattering problems. This tool enables one to estimate the shape of the unknown scatterers even if they are not necessarily point-like scatterers. This method is described and compared with existing sampling methods. Moreover, a mathematical derivation is provided for its validation, either in a free-space environment or in a metallic enclosure setup. Two-dimensional examples, based on measured data sets acquired in the circular microwave scanner developed at Institut Fresnel, are presented, which show that the method is computationally efficient and robust to noise. © 2012 IOP Publishing Ltd.

Zhang Q.,Nanjing University of Science and Technology | Jiang D.,Science and Technology on Electronic Information Control Laboratory | Wu W.,Nanjing University of Science and Technology
IEEE Antennas and Wireless Propagation Letters | Year: 2014

An integrated diversity antenna based on dual-feed cavity-backed slot is proposed and studied. The design is based on merging two slots into a diversity Y-shaped slot antenna using an inverted configuration. In order to achieve good isolation between the two slots, a slot stub is added at the merging corner part forming a Y-shaped slot antenna. The effects of different angles of the Y-junction in the diversity antenna on the mutual coupling are analyzed through HFSS simulations. The diversity performance of the proposed antenna is also evaluated by calculating the envelope correlation coefficient and mean effective gain ratio using the measured S-parameter results. © 2014 IEEE.

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