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181.
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183.
Optical add-drop multiplexers with low crosstalk 总被引:6,自引:0,他引:6
An Vu Tran Wen De Zhong Tucker R.C. Lauder R. 《Photonics Technology Letters, IEEE》2001,13(6):582-584
We propose and demonstrate three new optical add-drop multiplexer (OADM) architectures with simple and compact configuration and excellent crosstalk performance. The OADMs use a single multiport optical circulator and either one or two narrow-band fiber Bragg gratings, depending on the crosstalk requirement 相似文献
184.
Oraintara S. Tran T.D. Heller P.N. Nguyen T.Q. 《Signal Processing, IEEE Transactions on》2001,49(11):2659-2672
Parauninary linear-phase (PULP) M-channel uniform filterbanks, which are also known as the generalized lapped orthogonal transforms (GenLOTs), can be designed and implemented using lattice structures. This paper discusses how to impose regularity constraints onto the lattice structure of PULP filterbanks. These conditions are expressed in term of the rotation angles of the lattice components by which the resulting filterbanks are guaranteed to have one or two degrees of regularity, iterating these new regular filterbanks on the lowpass subband generates a large family of symmetric M-band orthonormal wavelets. Design procedures with many design examples are presented. Smooth interpolation using regular PULP filterbanks is illustrated through image coding experiments where the novel M-band wavelets consistently yield smoother reconstructed images and better perceptual quality 相似文献
185.
This article is concerned with the use of integrated radial‐basis‐function networks (IRBFNs) and nonoverlapping domain decompositions (DDs) for numerically solving one‐ and two‐dimensional elliptic problems. A substructuring technique is adopted, where subproblems are discretized by means of one‐dimensional IRBFNs. A distinguishing feature of the present DD technique is that the continuity of the RBF solution across the interfaces is enforced with one order higher than with conventional DD techniques. Several test problems governed by second‐ and fourth‐order differential equations are considered to investigate the accuracy of the proposed technique. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008 相似文献
186.
A. T. T. Tran S. Brossard M. M. Hyland B. J. James P. Munroe 《Plasma Chemistry and Plasma Processing》2009,29(6):475-495
Single NiCr splats were plasma-sprayed onto a polished stainless steel substrate held at room temperature. The splat-substrate
interface was characterized by focused ion beam and transmission electron microscopy. The frequent observation of NiO particles,
particularly in pores within the splat, and at the periphery of splat, suggests that the principal oxidation process occurs
at the substrate surface, where the splats are exposed to a water vapor-rich environment. It was also observed that the splat
adhered well in some locations where elemental-diffusion and jetting of the substrate occurred, suggestive of substrate melting.
A three-dimensional numerical model was developed to simulate the impact of a splat onto a substrate. The simulation shows
that the observation of the central pore in the splat and the phenomenon of substrate melting may occur. Based on these results,
the effect of water release on oxide formation and splat morphology can be explained. 相似文献
187.
Xianfu Lei Rose Qingyang Hu Lisheng Fan Pingzhi Fan Trung Q. Duong 《Wireless Communications and Mobile Computing》2016,16(6):624-642
In this paper, we consider switch‐and‐stay combining (SSC) in two‐way relay systems with two amplify‐and‐forward relays, one of which is activated to assist the information exchange between the two sources. The system operates in either analog network coding (ANC) protocol where the communication is only achieved with the help of the active relay or time‐division broadcast (TDBC) protocol where the direct link between two sources can be utilized to exploit more diversity gain. In both cases, we study the outage probability and bit error rate (BER) for Rayleigh fading channels. In particular, we derive closed‐form lower bounds for the outage probability and the average BER, which remain tight for different fading conditions. We also present asymptotic analysis for both the outage probability and the average BER at high signal‐to‐noise ratio. It is shown that SSC can achieve the full diversity order in two‐way relay systems for both ANC and TDBC protocols with proper switching thresholds. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
188.
Abstract
The reaction of N-[(S)-1-phenylethyl]-N-[1-(2-pyridinyl)methyl]amine (PEPMA) with Zn(ClO4)2 affords (PEPMA)2Zn(ClO4)2 at room temperature. The complex is characterized by elemental analysis, 1H-MNR and X-ray crystallography. The crystal system is orthorhombic with space group of P212121 and unit cell parameters: a = 8.6911(4), b = 9.7755(7), c = 37.275(2) ?, V = 3166.9(3) ?3, Z = 4, D x = 1.445 Mg/m3. The crystal structure reveals that zinc metal is ligated by two PEPMA ligands in a distorted tetrahedral fashion. Interestingly, both nitrogen atoms of amine at PEPMA to the central zinc metal exhibit (R)-configuration. 相似文献189.
We consider a continuous time stochastic individual based model for a population structured only by an inherited vector trait and with logistic interactions. We consider its limit in a context from adaptive dynamics: the population is large, the mutations are rare and the process is viewed in the timescale of mutations. Using averaging techniques due to Kurtz (in Lecture Notes in Control and Inform. Sci., vol. 177, pp. 186–209, 1992), we give a new proof of the convergence of the individual based model to the trait substitution sequence of Metz et al. (in Trends in Ecology and Evolution 7(6), 198–202, 1992), first worked out by Dieckman and Law (in Journal of Mathematical Biology 34(5–6), 579–612, 1996) and rigorously proved by Champagnat (in Theoretical Population Biology 69, 297–321, 2006): rigging the model such that “invasion implies substitution”, we obtain in the limit a process that jumps from one population equilibrium to another when mutations occur and invade the population. 相似文献
190.