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1.
基于微分搜索的高光谱图像非线性解混算法   总被引:2,自引:0,他引:2       下载免费PDF全文
陈雷  郭艳菊  葛宝臻 《电子学报》2017,45(2):337-345
针对线性混合模型在实际高光谱图像解混过程中的局限性,提出一种新的基于微分搜索的非线性高光谱图像解混算法.在广义双线性模型的基础上采用重构误差作为解混的目标函数,将非线性解混问题转化为最优化问题.将目标函数中的待求参数映射为微分搜索过程中的位置变量,利用微分搜索算法对目标函数进行优化求解.在求解过程中,通过执行搜索范围控制等机制满足高光谱图像解混的约束要求,进而求得丰度系数和非线性参数,实现非线性高光谱图像解混.仿真数据和真实遥感数据实验结果表明,所提出的非线性解混算法可以有效克服线性模型下解混算法的局限性,避免了由于使用梯度类优化方法而易陷入局部收敛的问题,较之其它高光谱图像解混算法具有更好的解混精度.  相似文献   

2.
为了克服传统的回溯算法在求解大型的约束满足问题时效率低,难以在合理的时间内求解这一问题。提出了基于启发式搜索的不完备性算法。结合不同算法特性,主要在蚁群优化元启发式约束求解算法的基础上提出了改进:一是在搜索之前用弧相容检查进行预处理以压缩搜索空间,二是提出了一种新的蚁群算法参数设置方案,提高算法的适应性。最后将改进后的算法应用于求解随机问题和组合优化问题。实验结果表明,改进后的算法求解效率得到大幅度提高。  相似文献   

3.
本文提出了一种求解带有昂贵约束的黑箱优化问题的算法,在响应面方法的框架下,采用三次径向基函数和薄板样条径向基函数的凸组合生成目标函数的响应面模型,并且在迭代过程中可以自适应的进行采样以平衡局部搜索与全局搜索。数值实验表明本文提出的自适应采样策略及响应面模型组合策略是增强求解带昂贵约束的黑箱全局优化问题的响应面算法性能的有效策略。  相似文献   

4.
冰壶比赛对阵编排问题是一个难于收敛的多约束优化问题.为此提出一种求解此类问题的逐层优化的单亲遗传算法.首先将待求解问题的多个约束进行分层;其次设计了靶向自交叉算子进行第一层优化以提高搜索效率,设计了定点-随机自交叉算子进行第二层优化以保持种群的多样性;最后,将改进的算法用于解决冰壶比赛对阵编排的多约束优化问题,构建了该问题的适应度函数.仿真实验表明,与粒子群算法和经典遗传算法相比,所提算法能够有效求解冰壶比赛对阵编排的多约束优化问题.  相似文献   

5.
两约束路由问题的近似解法   总被引:1,自引:1,他引:0  
张品  李乐民  王晟 《通信学报》2003,24(12):32-41
首先回顾了一些重要的QOS路由算法,然后对关于两约束路由问题(BCP,bi—constraint path problem)的线性搜索算法进行了数学分析,确定了搜索因子的范围和最佳搜索因子的值。基于以上分析,我们给出了BCP和单约束最短路径问题(RSP,restricted shortest path problem)的近似算法,并对算法性能进行了分析;最后,本文研究了采用非线性链路代价函数求解BCP。测试结果表明本文提出的算法是求解BCP和RSP的有效算法。  相似文献   

6.
设计高质量的核酸分子集合能有效提高DNA计算的可靠性、有效性和可求解问题的规模。DNA分子需要满足热力学约束、相似度约束、GC含量约束等多个相互冲突的目标函数,是典型的多目标优化问题。该文提出一种多目标进化策略(MOES)算法求解DNA分子序列设计问题,算法设计了随机碱基变异算子实现高效的局部搜索和全局搜索。改进的评价函数综合考虑了候选解的支配关系和冲突目标的平衡程度,选取符合DNA编码约束的核酸序列。实验结果证明,该文提出的算法具有高效的搜索效率和快速收敛能力,可以产生高质量的DNA序列集合,优于其他对比算法产生的DNA分子序列集合。  相似文献   

7.
多目标量子编码遗传算法   总被引:5,自引:0,他引:5  
如何使算法快速收敛到真正的Pareto前沿,并保持解集在前沿分布的均匀性是多目标优化算法重点研究解决的问题。该文提出一种基于量子遗传算法的多目标优化算法,利用量子遗传算法的高效全局搜索能力,在整个解空间内快速搜索多目标函数的Pareto最优解,利用量子遗传算法维持解集多样性的特点,使搜索到的Pareto最优解在前沿均匀分布。通过求解带约束的多目标函数优化问题,对该文算法的多目标优化性能进行了考察,并与NSGAII,PAES,MOPSO和Ray-Tai-Seows算法等知名多目标优化算法进行比较,结果证明了该文算法的有效性和先进性。  相似文献   

8.
免疫计算在求解约束优化问题中的应用   总被引:2,自引:2,他引:0  
介绍了约束条件的函数优化的主要问题及处理约束的解决方法,针对一般性非线性规划问题,采用免疫算法来进行处理。具体方法是:首先引入罚函数构造新的目标函数,而后运用免疫算法进行求解。通过测试表明,算法收到较好的效果。  相似文献   

9.
单尧  余兵  牛斌 《压电与声光》2019,41(6):786-788
针对简谐激励作用下的复合材料结构,通过优化结构的铺层、纤维铺设角度和铺层材料及优化结构表面压电材料的分布,实现了最小化结构振动响应。将压电材料的压电效应等效为压电感应力作用。应用离散材料优化(DMO)法对压电复合材料结构进行建模,以结构局部位移响应为优化目标函数,给定质量约束,建立优化问题模型,并使用移动渐近线法(MMA)求解优化问题。数值算例结果表明,该优化设计的振动响应明显小于初始设计的振动响应,说明该优化方法的有效性。  相似文献   

10.
多峰寻优问题是现实中经常遇到的问题,传统求解方法多易陷入局部最优.为了求解多峰优化问题,利用一种新的智能算法--社会认知算法,它对目标函数的解析性质没有要求,适合于非线性多蜂函数问题处理的求解,使搜索不容易陷入局部最优,并给出了该算法的原理和步骤.最后通过仿真实验结果表明,与其他优化算法比较,该算法概念清楚,计算简单,具有很好的全局寻优特性,表明了该方法的有效性,适用于求解于多峰寻优问题.  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

17.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

18.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

19.
Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.  相似文献   

20.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.  相似文献   

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