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Multi-focus image fusion based on block matching in 3D transform domain

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Journal of Systems Engineering and Electronics 2018年第2期29卷 415-428页

作者： YANG Dongsheng HU Shaohai LIU Shuaiqi ma xiaole SUN Yuchao Institute of Information Science Beijing Jiaotong UniversityBeijing 100044China Beijing Key Laboratory of Advanced Information Science and Network Technology Beijing 100044China College of Electronic and Information Engineering Hebei UniversityBaoding 071002China The Third Research Institute China Electronics Technology Group CorporationBeijing 100015China

Fusion methods based on multi-scale transforms have become the mainstream of the pixel-level image fusion. However,most of these methods cannot fully exploit spatial domain information of source images, which lead to the degradation of *** paper presents a fusion framework based on block-matching and 3D(BM3D) multi-scale transform. The algorithm first divides the image into different blocks and groups these 2D image blocks into 3D arrays by their similarity. Then it uses a 3D transform which consists of a 2D multi-scale and a 1D transform to transfer the arrays into transform coefficients, and then the obtained low-and high-coefficients are fused by different fusion rules. The final fused image is obtained from a series of fused 3D image block groups after the inverse transform by using an aggregation process. In the experimental part, we comparatively analyze some existing algorithms and the using of different transforms, e.g. non-subsampled Contourlet transform(NSCT), non-subsampled Shearlet transform(NSST), in the 3D transform step. Experimental results show that the proposed fusion framework can not only improve subjective visual effect, but also obtain better objective evaluation criteria than state-of-the-art methods.

关键词： image fusion block matching 3D transform block-matching and 3D(BM3D) non-subsampled Shearlet transform(NSST)

Design of luminescence in(Sr,Gd)Li(Al,Mg)_(3)N_(4):Eu^(2+)deep red phosphors via crystal field engineering for full-spectrum WLEDs

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Journal of Rare Earths 2023年第8期41卷 1127-1134,I0001页

作者： Qing Lin Tongyu Gao Yuanhong Liu Ronghui Liu Siwei Chen xiaole ma Chunlei Zhao National Engineering Research Center for Rare Earth GRINM Group Co.Ltd.Beijing 100088China GRIREM Advanced materials Co. Ltd.Beijing 100088China General Research Institute for Nonferrous Metals Beijing 100088China

Red phosphor,with longer wavelength,is highly desirable for full-spectrum *** deep red phosphors(Sr,Gd)Li(AI,Mg)_(3)N_(4):Eu^(2+)were designed from the initial model of SrLiAl_(3)N_(4):Eu^(2+)by structural *** correlations among structural evolution,crystal-field environment,and luminescence properties were *** Sr^(2+)with Gd^(3+)in(Sr,Gd)LiAl_(3)N_(4):Eu^(2+)leads to the enhanced crystal field splitting,larger Stokes shift,and increased structural polyhedron distortion differences,consequently resulting in spectral red-shift and *** further spectral tuning,Mg,with lower electronegativity,was also introduced to modify the local crystal structure,consequently resulting in a further red-shift towards 675 nm and enhanced photoluminescence intensity in(Sr,Gd)Li(AI,Mg)_(3)N_(4):Eu^(2+).What’s more,w-LEDs were fabricated by using blue LED chip,blue,green,red and deep red((Sr,Gd)Li(Al,Mg)_(3)N_(4):Eu^(2+))phosphors whose color rendering index were Ra 96.0 and *** above results demonstrate that the partial replacements of Sr^(2+)by Gd^(3+)and Al^(3+)by Mg^(2+)are effective methods for spectral modulation and(Sr,Gd)Li(AI,Mg)_(3)N_(4):Eu^(2+)phosphors are suitable for highquality full-spectrum WLEDs.

关键词： Full-spectrum WLEDs Structural modulation Deep red phosphor Rare earths

Carbon interstitial defects causing emission red shift in YAG:Ce phosphor:First-principles calculation

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Journal of Rare Earths 2018年第12期36卷 1239-1244页

作者： Yaling Zheng Weidong Zhuang Xianran Xing Ronghui Liu Yanfeng Li Yuanhong Liu Yunsheng Hu Xiaoxia Chen Lei Chen xiaole ma National Engineering Research Center for Rare Earth materials General Research Institute for Nonferrous Metals and Grirem Advanced Materials Co.Ltd. Department of Physical Chemistry University of Science & Technology Beijing

Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent ***,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce3+ion in Y3Al5O12:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O2-bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce3+atom and bigger 5 d centroid *** two factors cause the emission spectrum of Y3Al5O12(C):Ce3+red shift compared with that of Y3Al5O12:Ce3+. Moreover, with our comparison experiment, we find that the Y3Al5O12(C):Ce3+ has an obvious red shift compared with that of Y3Al5O12:Ce3+system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y3Al5O12:Ce3+,and provides a new route to tune the emission spectrum in Y3Al5O12:Ce3+.

关键词： YAG:Ce Carbon interstitial defects Red shift First-principles calculation Rare earths

White-light emitting single-phase phosphor La_3Si_6N_(11):Dy^(3+),Tb^(3+):Color tunable emission, thermal stability and energy transfer process

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Journal of Rare Earths 2019年第4期37卷 350-355页

作者： Yuanhong Liu Yuan Xue Ronghui Liu Mingyue Chen Guantong Chen Chunpei Yan Xia Zhang Yu'nan Zhou Wei Gao xiaole ma National Engineering Research Center for Rare Earth materials General Research Institute for Nonferrous Metals Grirem Advanced materials Co.Ltd.

A novel white-light emitting single-phase phosphor La_3 Si_6 N_(11):Dy^(3+),exhibiting two emission peaks centering at 475 and 575 nm, was prepared via conventional solid-state reactions. The structure and morphology of La_3 Si_6 N_(11):Dy^(3+)/Tb^(3+) were investigated by X-ray diffraction(XRD) and scanning electron microscopy(SEM). The emission colors can be tuned from white to yellow-green through increasing the Tb^(3+) concentration in La_3 Si_6 N_(11):Dy^(3+),Tb^(3+), The mechanism of energy transfer(ET) from Dy^(3+) to Tb^(3+) is confirmed according to the excitation,emission spectra and decay lifetimes curve. The temperaturedependent luminescence measurements of La_(2.83)Si_6 N_(11):0.1 Dy^(3+),0.07 Tb^(3+) were also performed, and a good thermal stability is shown, suggesting superior properties for the application as white lightemitting diodes(w-LEDs) phosphor.

关键词： Single-phase White emission Energy transfer Rare earths

AODV-Clustering Routing Protocol for Large Tactical Mobile Ad Hoc Network

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AODV-Clustering Routing Protocol for Large Tactical Mobile A...

一种无数值积分的间断Galerkin有限元方法

第十三届中国体视学与图像分析学术会议

作者： Haibo Jiang Yaofei ma Dongsheng Hong xiaole ma School of Automation Science and Electrical Engineering Beihang University

maNET is generally employed in military and emergencies due to its flexibility and easy-touse. However,most flat routing protocols flood their route request(RREQ) packets to overall network which will lead to high routing overhead and poor *** a result,these routing protocols cant perform well when the network grows larger,or the nodes are moving *** address this issue,this paper proposes a cluster based routing protocol named AODV-clustering,which partitions the network into several *** experiments are conducted using NS2.34,and the results demonstrate that the proposed protocol can improve the network performance by decreasing the routing overhead and increasing the packet delivery ratio.

关键词： AODV AODV-clustering routing overhead packet delivery ratio NS2

来源： cnki会议评论

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空气动力学学报 2018年第4期36卷 596-604页

作者：马小乐曹伟天津大学机械工程学院力学系天津300072

在使用间断Galerkin有限元方法的计算过程中,需要构造相应的积分表达式作为数值求解的出发点,继而会引入体积分和面积分。对于这些积分项的值,一般需要通过数值积分的方法获得。当需要使用高阶间断Galerkin有限元方法时,数值积分计算精... 详细信息

在使用间断Galerkin有限元方法的计算过程中,需要构造相应的积分表达式作为数值求解的出发点,继而会引入体积分和面积分。对于这些积分项的值,一般需要通过数值积分的方法获得。当需要使用高阶间断Galerkin有限元方法时,数值积分计算精度的要求会相应地增加,其所需的计算量将变得很大,而数值积分的计算量又在很大程度上决定了间断Galerkin有限元方法的计算效率。针对这一问题,通过建立Lagrange插值多项式基函数和Jacobi正交多项式基函数的一定关系,构造了一种无数值积分的间断Galerkin有限元方法显式半离散格式,并对不同条件下的线性和非线性一维、二维守恒律进行了直接数值模拟,得到了理想的数值结果。该方法不再需要通过数值积分来计算每个单元的积分项,而且有效地达到了间断Galerkin有限元方法的高阶精度,其对于构造更为高效的高阶间断Galerkin有限元计算方法具有非常显著的意义。

关键词：间断Galerkin有限元 Jacobi正交多项式显式半离散格式无数值积分高精度

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基于无监督深度学习的红外与可见光图像融合

航空学报 2022年第S1期43卷 173-181页

作者：孙秀一胡绍海马晓乐北京交通大学信息科学研究所北京100044 现代信息科学与网络技术北京市重点实验室北京100044

目前已知的多数基于卷积神经网络的红外与可见光图像融合模型没有充分利用来自可见光源图像的层次特征,因此导致融合图像细节纹理不足。受残差网络和密集网络的启发,提出了一种基于无监督深度学习的图像融合算法来解决融合图像细节纹理... 详细信息

目前已知的多数基于卷积神经网络的红外与可见光图像融合模型没有充分利用来自可见光源图像的层次特征,因此导致融合图像细节纹理不足。受残差网络和密集网络的启发,提出了一种基于无监督深度学习的图像融合算法来解决融合图像细节纹理信息不足的问题。使用的残差密集块有连续存储机制,最大程度地保留每层的特征信息,局部残差融合和全局残差融合的设计有利于学习图像中的结构纹理。此外,为了更好地保留可见光图像中的细节纹理,引入了生成对抗网络对数据集进行无监督学习。主客观实验表明,该算法不仅获得了良好的视觉融合效果,融合图像具有更多的边缘纹理信息,在客观评价指标上对比现有优秀的算法也较大的提升。

关键词：无监督学习残差密集网络生成对抗网络红外图像可见光图像图像融合

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基于多形态学成分分析的图像融合

同济大学学报（自然科学版） 2024年第1期52卷 10-17页

作者：马晓乐王志海胡绍海北京交通大学计算机与信息技术学院北京100044

将多尺度分解与稀疏表示相结合,提出了一种基于多形态学成分分析(MCA)的图像融合算法。采用基于联合稀疏表示(JSR)的方法融合卡通子图像中的冗余和互补信息,并利用基于方向特征的方法融合具有更多细节信息和噪声的纹理子图像。结果表明... 详细信息

将多尺度分解与稀疏表示相结合,提出了一种基于多形态学成分分析(MCA)的图像融合算法。采用基于联合稀疏表示(JSR)的方法融合卡通子图像中的冗余和互补信息,并利用基于方向特征的方法融合具有更多细节信息和噪声的纹理子图像。结果表明,提出的图像融合算法在主观视觉效果和客观评价指标上均优于先进的图像融合算法。

关键词：图像融合多尺度分解形态学成分分析(MCA) 联合稀疏表示(JSR)

Preparation,structure and luminescence properties of deep red phosphors SrSiN2:Eu^2+

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Journal of Rare Earths 2016年第1期34卷 30-35页

作者：陈磊刘荣辉庄卫东刘元红胡运生马小乐胡斌 National Engineering Research Center for Rare Earth materials General Research Institute for Nonferrous Metals Grirem Advanced Materials Co. Ltd Beijing 100088 China

This paper reported a novel synthetic route to Eu2＋ doped SrSiN2 deep red phosphors for white light-emitting diodes. A series of single-phased and high-efficiency SrSiN2：Eu2＋ red phosphors were synthesized based on this method. Their structure, morphology, luminescence, quantum efficiency （QE） and thermal quenching properties were investigated and compared with those of SrSiN2： Eu2＋ prepared by the conventional route. It was found that the addition of a small amount of Si3N4 could promote the formation of SrSiN2 from Sr2SisN8 phase. A highly uniform rod-shaped morphology was obtained based on this method. The X-ray powder diffraction and the Rietveld refinement analysis identified the preferential crystalline orientation growth. Under the blue light excitation, Eu2＋ doped SrSiN2 phosphors showed excellent optical properties. Compared with those prepared by the conventional approaches, the external QE of SrSiN2：Eu2＋ phosphor was greatly improved, allowing it a promising phosphor for white LEDs.

关键词： red phosphors nitride quantum efficiency Sr2Si5N8 structure rare earths