DTNs overcome the problems associated with intermittent connectivity, long or variable delay, asymmetric data rates, and high error rates by using store-carry-forward message switching. In DTNs, a node is an entity wi...
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ISBN:
(纸本)9781509034857
DTNs overcome the problems associated with intermittent connectivity, long or variable delay, asymmetric data rates, and high error rates by using store-carry-forward message switching. In DTNs, a node is an entity with a bundle layer. A node may be a host, router, or gateway (or some combination) acting as a source, destination, or forwarder of bundles. In addition, the performance of node shows great differences. However, the previous DTN routings show blindly and randomly, which do not measure the performance of node when they forward messages. To deal with this issue, we present the concept of Node Connection Intensity (NCI) and Node Connection Stability (NCS), then propose a routing scheme based on Spray-and-Wait and Connecting-Capability of Node (SW-CCN), which evaluate relay node's forward capability synthetically according to the NCI and the NCS. The SW-CCN routing can allocate message replications dynamically and solve the problem of selecting the relay node blindly. Compared with the classical routing protocols, the simulation results show that the proposed algorithm can significantly enhance delivery rate and improve network performance.
In this letter, we present a three-dimensional (3-D) artificial anisotropy weakly conditional stability finite-difference time-domain (WCS-FDTD) method to achieve better dispersion performance. This artificial anisotr...
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ISBN:
(纸本)9781509047444
In this letter, we present a three-dimensional (3-D) artificial anisotropy weakly conditional stability finite-difference time-domain (WCS-FDTD) method to achieve better dispersion performance. This artificial anisotropy WCS-FDTD algorithm can minimize the dispersion error for arbitrary incident angles and different time-step sizes. Stability analysis presents that this algorithm is weakly conditionally stable if proper artificial anisotropy parameter values are chosen. Dispersion analysis illustrates the error of the numerical phase velocity can be controlled.
According to granular computing, Pawlak s rough set theory is based on a single granulation; however, multi-granulation rough set theory is applied to describe an uncertain concept by multiple binary relations. In thi...
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According to granular computing, Pawlak s rough set theory is based on a single granulation; however, multi-granulation rough set theory is applied to describe an uncertain concept by multiple binary relations. In this paper, the multi-granulation rough set approach with maximal consistent block technique has been introduced into the incomplete information system. Based on this maximal consistent block technique, a new pessimistic multi-granulation rough set in the incomplete information system is proposed. The lower and upper approximations of an uncertain set are defined based on this new model, and some properties are proposed for this new model.
Four circulant codes form a special class of 2-generator, index 4, quasi-cyclic codes. Under some conditions on their generator matrices they can be shown to be self-dual. Artin primitive root conjecture shows the exi...
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A broadband dual-polarized magneto-electric dipole antenna excited by Γ-shaped strips is presented in this communication. The proposed antenna contains three parts. The radiating element of the proposed antenna is a ...
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ISBN:
(纸本)9781538616093
A broadband dual-polarized magneto-electric dipole antenna excited by Γ-shaped strips is presented in this communication. The proposed antenna contains three parts. The radiating element of the proposed antenna is a combination of the vertically oriented shorted patch, the planar dipole and the bottom plate. The two orthogonal Γ-shaped feeding strips connected with 50 Ω SMA launchers are used to excite the proposed antenna. The corner reflector can effectively improve the radiation performance of the proposed antenna. As shown in simulated results, the impedance bandwidth of the proposed antenna is 48% for standing-wave ratio (SWR) ≤2 (0.86-2.47 GHz), the available bandwidth of the antenna covers the 2G/3G/LTE bands, and the antenna obtains a stable gain that the average value is 10 dBi. Meanwhile, the antenna has good performance in radiation characteristics. The proposed antenna can be applied to the base station communication systems.
A compact multiband omnidirectional antenna for the reception of GNSS signals on artillery projectiles is designed in this paper. The proposed antenna consists of a metallic cone comprising a T-shaped monopole. It exh...
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Quasi-twisted codes of fixed index > 1 have been shown recently to be asymptotically good (A. Alahmadi, C. Güneri, H. Shoaib, P. Solé, 2017). We use this result to construct asymptotically good additive c...
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Purpose. Aiming at solving the fusion issue of surveillance images, a simple and efficient fusion framework using block compressed sensing sampling (BCSS) is proposed in this paper, which consists of two fusion method...
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We construct trace codes over Z4 by using Boolean functions and skew sets, respectively. Their Lee weight distribution is studied by using a Galois ring version of the Walsh-Hadamard transform and exponential sums. We...
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In this Letter, we propose a color holographic zoom system based on a liquid lens. We use the spatial multiplexing method to realize color reconstruction. By controlling the focal lengths of the liquid lens and the en...
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In this Letter, we propose a color holographic zoom system based on a liquid lens. We use the spatial multiplexing method to realize color reconstruction. By controlling the focal lengths of the liquid lens and the encoded digital lens on the spatial light modulator panel, we can change the magnification of the reconstructed image very quickly, without mechanical parts and keeping the output plane stationary.
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