Yang S.,Science and Technology on Electronic Information Control Laboratory |
Tang W.,University of Electronic Science and Technology of China
Proceedings - UKSim-AMSS 8th European Modelling Symposium on Computer Modelling and Simulation, EMS 2014 | Year: 2014
In this paper, we discuss the intra- and inter-path interference problems of multiple-path transmission in multiple-hop wireless networks, and show that classical node-disjoint paths are highly sensible to these problems, thus incapable of providing ideal throughput for multiple-path transmission. To tackle the problems, this paper gives a detailed analysis to the intra- and inter-path interference problems based on graph theory. Being aware that node-disjoint ness is no longer adequate to describe the properties of paths that are capable to provide the maximum throughput for multiple-path transmission, the new concepts of irreducible and neighbor-disjoint paths are proposed. Via detailed discussion, the theoretical upper bound of throughput achievable by multiple-path transmission via irreducible and neighbor-disjoint paths with at least 3 hops is given. It's proved that, by using irreducible and neighbor-disjoint paths, multiple-path transmission is capable to achieve near capacity throughput. © 2014 IEEE.
Yu T.,University of Sichuan |
Yu T.,Science and Technology on Electronic Information Control Laboratory |
Luo M.-K.,University of Sichuan |
Hua Y.,Science and Technology on Electronic Information Control Laboratory
Wuli Xuebao/Acta Physica Sinica | Year: 2013
When moving in viscous medium, the mass of a Brownian particle is fluctuant and its damping force depends on the past velocity history. Therefore, in order to investigate the characteristics of Brownian motion in viscous medium, fractional harmonic oscillator is proposed in this paper for the first time so for as we know. First, the Shapiro-Loginov formula is fractionized to solve fractional stochastic differential equation with exponential correlative stochastic coefficients. Then, by using stochastic averaging method and fractional Shapiro-Loginov formula, the analytical expression of a system's steady response amplitude is presented and the system's resonant behavior is discussed accordingly. Finally, the reliability of theoretical results is tested by simulation experiments. All the research shows that: (1) Stochastic resonant behavior can be induced by mass fluctuation noise. (2) Parameter-induced resonance can be induced by memory damping force. (3) Under different parameter conditions, the system's resonant forms are diverse. © 2013 Chinese Physical Society.
Zou X.,Southwest Jiaotong University |
Zou X.,INRS - Institute National de la Recherche Scientifique |
Zou X.,Science and Technology on Electronic Information Control Laboratory |
Zou X.,University of Ottawa |
And 6 more authors.
Optics Letters | Year: 2013
Optical filters with an ultranarrow and rectangular spectral response are highly desired for high-resolution optical/ electrical signal processing. An all-fiber optical filter based on a fiber Bragg grating with a large number of phase shifts is designed and fabricated. The measured spectral response shows a 3 dB bandwidth of 650 MHz and a rectangular shape factor of 0.513 at the 25 dB bandwidth. This is the narrowest rectangular bandpass response ever reported for an all-fiber filter, to the best of our knowledge. The filter has also the intrinsic advantages of an all-fiber implementation. © 2013 Optical Society of America.
Zhang X.,University of Sichuan |
Zhang X.,Science and Technology on Electronic Information Control Laboratory |
Wei C.,State University of New York at Buffalo |
Liu Y.,University of Sichuan |
And 2 more authors.
Annals of Physics | Year: 2014
In this paper we use Dirac function to construct a fractional operator called fractional corresponding operator, which is the general form of momentum corresponding operator. Then we give a judging theorem for this operator and with this judging theorem we prove that R-L, G-L, Caputo, Riesz fractional derivative operator and fractional derivative operator based on generalized functions, which are the most popular ones, coincide with the fractional corresponding operator. As a typical application, we use the fractional corresponding operator to construct a new fractional quantization scheme and then derive a uniform fractional Schrödinger equation in form. Additionally, we find that the five forms of fractional Schrödinger equation belong to the particular cases. As another main result of this paper, we use fractional corresponding operator to generalize fractional quantization scheme by using Lévy path integral and use it to derive the corresponding general form of fractional Schrödinger equation, which consequently proves that these two quantization schemes are equivalent. Meanwhile, relations between the theory in fractional quantum mechanics and that in classic quantum mechanics are also discussed. As a physical example, we consider a particle in an infinite potential well. We give its wave functions and energy spectrums in two ways and find that both results are the same. © 2014 Elsevier Inc.
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
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.
Zhang W.-J.,Science and Technology on Electronic Information Control Laboratory |
Gao Z.-Z.,Science and Technology on Electronic Information Control Laboratory |
Xu B.,Science and Technology on Electronic Information Control Laboratory |
Gao S.-W.,Science and Technology on Electronic Information Control Laboratory
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2011
The improvement of the capability to detect dim targets is commonly realized by long-term accumulation. In order to detect those high speed targets, a novel radar signal processing method based on Keystone transform for surveillance radar is presented, which is able to compensate the range migration effect caused by long dwell time and high speed motion of targets. The target energy is accumulated effectively, and Doppler ambiguity is solved by data fusion. Finally, the target detection and parameter estimation are implemented. The proposed method can be used to detect multiple dim targets with different ranges and velocities by long-term coherent accumulation. Meanwhile, the speed measurement resolution is improved significantly with the number of pulses increased. Multi-target simulation results illustrate the effectivity of the proposed method.
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 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.
Wang J.,Xiamen University |
Wang J.,Science and Technology on Electronic Information Control Laboratory |
Luo Z.,Xiamen University |
Zhou M.,Xiamen University |
And 6 more authors.
IEEE Photonics Journal | Year: 2012
We demonstrate the fabrication of graphene-deposited tapered fibers (GDTFs), which can be used as saturable absorbers (SAs) for pulsed lasers. The advantages of GDTF SAs include flexibility, all-fiber configuration, and high optical damage threshold. The fabrication process is based on the interaction of the evanescent field of a tapered fiber with graphene. By in situ monitoring the transmitted power, the deposition process can be controlled, and the GDTF with a desirable level of nonsaturable absorption loss can be fabricated. We also study the dynamic deposition process by employing different waist diameters of tapered fibers and the different deposition powers. The results show that the deposition time can be significantly shortened with stronger evanescent field by decreasing the taper diameter or increasing the deposition power. Furthermore, by exploiting the GDTF as an intracavity passive power modulating element, we demonstrate efficient Q-switched and mode-locked erbium-doped fiber lasers, respectively. © 2012 IEEE.