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Self-trapping Characteristics of Partially Coherent Optical Beam in Photonic Crystal Fiber under Compton Scattering
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作者 HAO Dong-shan LI Ji-zhou 《Semiconductor Photonics and Technology》 CAS 2007年第2期136-140,共5页
Using the mutually coherent function, the self-trapping of the circle partially coherent optical beam in the total internal reflective photonic crystal fiber(TIRPCF) under Compton scattering is studied. The study show... Using the mutually coherent function, the self-trapping of the circle partially coherent optical beam in the total internal reflective photonic crystal fiber(TIRPCF) under Compton scattering is studied. The study shows that the composition of the non-coherent optical beam in the optical spectrum and the diffraction effect are decreased by Compton scattering, and the probability of forming the soliton is greatly increased. The vibration peak value in the propagation, compressed degree, changed cycle, and radius of the soliton are all smaller than those before the scattering, but its coherent radius is larger than that before the scattering. In this propagation, the self-focusing plays a key role. 展开更多
关键词 spatial soliton partially coherent optical beam coherence radius Compton scattering
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Non-reference virtual view quality evaluation of MVD
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作者 张艳 安平 +2 位作者 张秋闻 王元庆 张兆杨 《Journal of Shanghai University(English Edition)》 CAS 2011年第4期342-346,共5页
The quality of virtual view based on multi-view video (MVD) plus depth format is often evaluated by PSNR or subjectively judged. However, due to synthesizing arbitrary view images, the virtual view images mostly hav... The quality of virtual view based on multi-view video (MVD) plus depth format is often evaluated by PSNR or subjectively judged. However, due to synthesizing arbitrary view images, the virtual view images mostly have no reference images and are only assessed using non-reference. Virtual view images synthesized by depth estimation reference software (DERS) and view synthesis reference software (VSRS) often accompanied with blockiness and other distortions on the edge. In addition, matching level for the depth map and the corresponding texture maps of left and right views also affects the quality of the virtual view. This paper compares the edge similarity of the depth and the corresponding texture maps which generate the intermediate virtual view and combined with the virtual view's blockiness which causing blur to evaluate the quality of the virtual view. Experiment results show that the proposed method can reflect the quality of the virtual view better. 展开更多
关键词 non-reference quality evaluation virtual view multi-view video (MVD) plus depth free viewpoint television (FTV)
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An Improved Sparrow Search Algorithm for Node Localization in WSN 被引量:1
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作者 RThenmozhi Abdul Wahid Nasir +4 位作者 Vijaya Krishna Sonthi TAvudaiappan Seifedine Kadry Kuntha Pin Yunyoung Nam 《Computers, Materials & Continua》 SCIE EI 2022年第4期2037-2051,共15页
Wireless sensor networks(WSN)comprise a set of numerous cheap sensors placed in the target region.A primary function of the WSN is to avail the location details of the event occurrences or the node.A major challenge i... Wireless sensor networks(WSN)comprise a set of numerous cheap sensors placed in the target region.A primary function of the WSN is to avail the location details of the event occurrences or the node.A major challenge in WSN is node localization which plays an important role in data gathering applications.Since GPS is expensive and inaccurate in indoor regions,effective node localization techniques are needed.The major intention of localization is for determining the place of node in short period with minimum computation.To achieve this,bio-inspired algorithms are used and node localization is assumed as an optimization problem in a multidimensional space.This paper introduces a new Sparrow Search Algorithm with Doppler Effect(SSA-DE)for Node Localization in Wireless Networks.The SSA is generally stimulated by the group wisdom,foraging,and anti-predation behaviors of sparrows.Besides,the Doppler Effect is incorporated into the SSA to further improve the node localization performance.In addition,the SSA-DE model defines the position of node in an iterative manner using Euclidian distance as the fitness function.The presented SSA-DE model is implanted in MATLAB R2014.An extensive set of experimentation is carried out and the results are examined under a varying number of anchor nodes and ranging error.The attained experimental outcome ensured the superior efficiency of the SSA-DE technique over the existing techniques. 展开更多
关键词 LOCALIZATION wireless networks
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Tunable attenuator based on polymer microstructured optical fibers
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作者 ZHANG Ye-jin HE Li-na JI Heng YANG Si-gang CHEN Ming XIE Shi-zhong 《Optoelectronics Letters》 EI 2007年第1期47-49,共3页
Based on polymer microstructured optical fibers (PMOF) and selective liquid crystal injection technology, a novel tem- perature control tunable attenuator is designed theoretically in this paper. In our experiments, P... Based on polymer microstructured optical fibers (PMOF) and selective liquid crystal injection technology, a novel tem- perature control tunable attenuator is designed theoretically in this paper. In our experiments, PMMA microstructured optical fibers with high performance are drawn successfully and the selective injection of liquid crystal 5CB into micro- holes is realized. The tunable attenuator is fabricated with an extinction ratio of over 60dB, which agrees well with the design. 展开更多
关键词 聚合物微结构光纤 调谐 衰减器 选择性晶体注入
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Photon Polarizationin Photonic Crystal Fibers under Compton Scattering
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作者 HAO Dong-shan ZHANG Xiao-fu 《Semiconductor Photonics and Technology》 CAS 2007年第4期305-309,共5页
Using the quantum invariant theory and unitary transformation means, we study the influences of multi-photon nonlinear Compton scattering on the photon polarization in photonic crystal fibers(PCF). The results show th... Using the quantum invariant theory and unitary transformation means, we study the influences of multi-photon nonlinear Compton scattering on the photon polarization in photonic crystal fibers(PCF). The results show that the photon polarization of the incident photon changes a lot due to scattered optical, and its general geometric phase factor, Hamiton number and evolution operator are definited both by the incident and scattered optical. 展开更多
关键词 eometric phase factor photonic crystal fiber INVARIANT multi-photon nonlinear Compton scattering unitary transformation
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3DV quality model based depth maps for view synthesis in FTV system
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作者 张秋闻 安平 +2 位作者 张艳 张兆杨 王元庆 《Journal of Shanghai University(English Edition)》 CAS 2011年第4期335-341,共7页
Depth maps are used for synthesis virtual view in free-viewpoint television (FTV) systems. When depth maps are derived using existing depth estimation methods, the depth distortions will cause undesirable artifacts ... Depth maps are used for synthesis virtual view in free-viewpoint television (FTV) systems. When depth maps are derived using existing depth estimation methods, the depth distortions will cause undesirable artifacts in the synthesized views. To solve this problem, a 3D video quality model base depth maps (D-3DV) for virtual view synthesis and depth map coding in the FTV applications is proposed. First, the relationships between distortions in coded depth map and rendered view are derived. Then, a precisely 3DV quality model based depth characteristics is develop for the synthesized virtual views. Finally, based on D-3DV model, a multilateral filtering is applied as a pre-processed filter to reduce rendering artifacts. The experimental results evaluated by objective and subjective methods indicate that the proposed D-3DV model can reduce bit-rate of depth coding and achieve better rendering quality. 展开更多
关键词 free-viewpoint television (FTV) 3D video quality model base depth maps (D-3DV) view synthesis
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A new measure to characterize multifractality of sleep electroencephalogram 被引量:3
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作者 MA Qianli NING Xinbao +1 位作者 WANG Jun BIAN Chunhua 《Chinese Science Bulletin》 SCIE EI CAS 2006年第24期3059-3064,共6页
Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophi... Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophisticated behavior of electroencephalogram (EEG). The multifractal for-malism reveals more “hidden” information of EEG by using singularity spectrum to characterize its nonlin-ear dynamics. In this paper,the zero-crossing time intervals of sleep EEG were studied using multifractal analysis. A new multifractal measure Δasα was pro-posed to describe the asymmetry of singularity spec-trum,and compared with the singularity strength range Δα that was normally used as a degree indi-cator of multifractality. One-way analysis of variance and multiple comparison tests showed that the new measure we proposed gave better discrimination of sleep stages,especially in the discrimination be-tween sleep and awake,and between sleep stages 3 and 4. 展开更多
关键词 睡眠 脑电图 EEG 奇异谱 多分形体
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