The optical properties of nanostructures with nonlocal effects is analysied by the finite element method method. The nonlocal effects can be described by a spatially nonlocal dielectric function with Drude model plus ...
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ISBN:
(纸本)9781509060948
The optical properties of nanostructures with nonlocal effects is analysied by the finite element method method. The nonlocal effects can be described by a spatially nonlocal dielectric function with Drude model plus two Lorentz pole oscillator dielectric model. The optical properties of Au nanotubes with different radii, distance of junctions, can be determined by tuning the corresponding parameters to obtain the remarkable nonlocal effects, which should be taken into consideration in real optical device design. Our results can be used as a reference in design of realistic sub-wavelength devices.
In the era of big data, data intensive applications have posed new challenges to the field of service composition. How to select the optimal composited service from thousands of functionally equivalent services but di...
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In the era of big data, data intensive applications have posed new challenges to the field of service composition. How to select the optimal composited service from thousands of functionally equivalent services but different Quality of Service(Qo S) attributes has become a hot research in service computing. As a consequence,in this paper, we propose a novel algorithm MR-IDPSO(Map Reduce based on Improved Discrete Particle Swarm Optimization), which makes use of the improved discrete Particle Swarm Optimization(PSO) with the Map Reduce to solve large-scale dynamic service composition. Experiments show that our algorithm outperforms the parallel genetic algorithm in terms of solution quality and is efficient for large-scale dynamic service composition. In addition,the experimental results also demonstrate that the performance of MR-IDPSO becomes more better with increasing number of candidate services.
Large-scale service composition has become an important research topic in Service-Oriented computing（SOC）. Quality of Service（Qo S） has been mostly applied to represent nonfunctional properties of web services and...
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Large-scale service composition has become an important research topic in Service-Oriented computing（SOC）. Quality of Service（Qo S） has been mostly applied to represent nonfunctional properties of web services and to differentiate those with the same functionality. Many studies for measuring service composition in terms of Qo S have been completed. Among current popular optimization methods for service composition, the exhaustion method has some disadvantages such as requiring a large number of calculations and poor scalability. Similarly,the traditional evolutionary computation method has defects such as exhibiting slow convergence speed and falling easily into the local optimum. In order to solve these problems, an improved optimization algorithm, WS FOA（Web Service composition based on Fruit Fly Optimization Algorithm） for service composition, was proposed, on the basis of the modeling of service composition and the FOA. Simulated experiments demonstrated that the algorithm is effective, feasible, stable, and possesses good global searching ability.
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.
The community detection was performed from the perspective of links, and we proposed an inhibition method against social network worms. Firstly, a community detection algorithm was proposed, which based on link cluste...
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The community detection was performed from the perspective of links, and we proposed an inhibition method against social network worms. Firstly, a community detection algorithm was proposed, which based on link clustering, and we got related link incremental information through the network structure information at various time points. In order to obtain the link communities, we adopted an improved link partition density function to dispose the link incremental information. Next, we gave three selection strategies of key nodes in community and proposed corresponding worm inhibition method. Finally, on the basis of real web data sets, we applied community detection and worm inhibition experiments to prove validity of algorithm in this paper.
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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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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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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