首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
刘夫成  高尚 《信息技术》2013,(2):42-44,47
针对传统的个人信誉评估方法存在的缺陷,提出了一种基于K均值聚类和支持向量机结合的个人信誉评估方法。该方法先将测试数据集进行聚类,根据数据离聚类的数据分布来选取合适数据训练支持向量机,然后利用支持向量机进行分类。结果表明,同单一利用支持向量机分类进行比较,该方法减少了训练时间,同时具有较高的测试精度,比传统的个人信誉评估模型有更好的效果。  相似文献   

2.
胡善江  贺岩  陶邦一  俞家勇  陈卫标 《红外与激光工程》2019,48(11):1113004-1113004(8)
机载激光雷达的海陆波形分类对于沿海地区及其变化性质的研究至关重要。提出了一种在原始的机载激光雷达回波上使用深度学习进行分类的方法。构建全连接神经网络和一维卷积神经网络(CNN),在一个测量海域的数据集上进行训练和测试,最优模型获得了99.6%的分类精度。该最优模型对来自不同测量海域的数据进行分类,分类精度达到了95.6%,相比支持向量机方法,处理速度提高了约52%。结果表明:深度学习方法对机载激光雷达回波波形的分类具有较高的精度和速度,它可以进一步作为通过机载激光测深技术对海底种类进行分类的候选方法。  相似文献   

3.
陈素根  吴小俊 《电子学报》2017,45(2):408-416
针对投影孪生支持向量机(Projection Twin Support Vector Machine,PTSVM)在训练和求解过程中存在的问题,提出了一类改进的投影孪生支持向量机(Improved PTSVM),简称为IPTSVM.该文首先构造了改进的线性投影孪生支持向量机,然后利用核技巧轻松将其推广到了非线性形式.本文的主要贡献有:(1)提出了投影孪生支持向量机的新模型,克服了原始PTSVM在训练之前需要求解两个逆矩阵的问题;(2)继承了传统SVM(Support Vector Machine)的精髓,利用核技巧直接将线性IPTSVM推广到非线性形式;(3)引入了一个新的参数,可以调节模型的性能,提高了IPTSVM的分类精度.实验结果表明,与PTSVM算法相比较,IPTSVM不仅提高了分类精度,而且克服了PTSVM的一些不足.  相似文献   

4.
基于K最近邻的支持向量机快速训练算法   总被引:2,自引:0,他引:2  
传统支持向量机训练大规模样本时间和空间开销大,使其应用受到了很大限制。为了提高支持向量机的训练速度,根据支持向量机的基本原理,应用K最近邻思想来筛选训练样本集,提出了基于K最近邻的支持向量机快速训练算法(KNN-SVM)。算法首先选取一部分最有可能成为支持向量的样本——边界向量,然后用边界向量集代替训练样本集进行支持向量机训练,大幅度减少了训练样本的数量,使支持向量机的训练速度显著提高。同时,由于边界向量包含了支持向量,因此,支持向量机的分类能力没有受到影响。仿真实验结果表明,与传统支持向量机相比,在分类精度相同的情况下,算法能够有效地提高支持向量机的训练速度,而且还可以提高支持向量机的分类速度和推广能力。  相似文献   

5.
方佳艳  刘峤  吴德  秦志光 《电子学报》2018,46(11):2714-2724
在用于非线性分类的光滑支持向量机(SSVM)模型中,核函数必须满足Mercer's条件,由此限制了核函数的选择范围;并且在面对大规模数据集时,SSVM模型的计算复杂度很高,训练时间长.针对这两点缺陷提出了基于模糊C-均值的相似性特征转换光滑支持向量机模型(SFT-SSVM-FCM).首先,运用基于相似性的特征转换,使得核函数不需要再满足Mercer's条件,从而拓宽了核函数的选择范围;其次,运用模糊C-均值(FCM)分群技术,将完整的训练数据集划分成若干子簇,分别在每一个子簇上进行已经过相似性特征转换的SSVM模型训练.实验表明:与传统的SVM、SSVM模型及一系列变体模型相比较,该新模型在训练时间、分类精度方面都具有更好的表现.  相似文献   

6.
针对数字图像的高精度分类问题,提出了一种新型数字图像分类算法。在该算法中,局部二值模式(Local Binary Patterns,LBP)算子被用于数字图像的LBP图构建LBP图的直方图被用于构建图像样本的特征向量;大量样本的特征向量构建的训练数据集被送入最小二乘支持向量机(Least Squares Support Vector Machines,LSSVM)进行最优分类模型的构建。在测试数据集的分类测试中,对本文所提出算法与传统支持向量机算法、极限学习机算法和Hopfield神经网络方法进行了比较,在宏查准率、宏查全率和分类时间几个典型性能指标的测试方面,本文所提出的LBP-LSSVM算法均表现出了优异的性能。  相似文献   

7.
电子邮件分类有利于垃圾邮件的过滤,节省网络资源。为了提高邮件分类的精度,提出了改进支持向量机的电子邮件分类器模型。首先提取电子邮件的原始特征,并采用主成分分析法对特征进行选择,减少特征数量,提高邮件分类效率;然后采用支持向量机建立电子邮件分类器,并对传统支持向量机参数选择方法进行改进,改善邮件分类效果,最后采用邮件分类的标准数据库——UCI进行性能分析。结果表明,改进支持向量机解决了当前电子邮件分类模型的不足,获得了理想的电子邮件分类效果,分类结果可以帮助管理人员拦截垃圾邮件。  相似文献   

8.
梁楠  邹志红 《电讯技术》2020,(3):331-337
在多传感器水质数据融合领域,证据理论是有效的数据融合方法之一,但基本概率分配一般不易确定,从而使数据融合能力难以有效发挥。支持向量机是统计学习理论之上的高级分类算法,具有普适性和全局优化等特点,但输出的基本概率分配有待进一步提高。提出了一种基于证据理论和新型模糊支持向量机相结合的数据融合方法,通过建立基于分类超平面距离的模糊隶属度,训练模糊支持向量机提高传统支持向量机的基本概率分配,并结合证据理论进行海河水质数据融合。通过证据理论分别结合支持向量机和模糊综合评价法与上述方法进行对比实验,经精度、平均绝对百分误差、均方根误差等指标验证,精度提高10. 5%,表明所提方法是一种可靠的多传感器的水质融合方法,较其他方法具有更高的融合精度。  相似文献   

9.
《信息技术》2018,(4):37-40
文中提出了一种动态改进的遗传算法和支持向量回归机相耦合的水质预测方法,改进了传统遗传算法中交叉和变异概率固定的问题,尽可能避免陷入局部最优的问题。在对大理弥苴河水质进行大量实际监测的基础上,分别采用BP神经网络,遗传算法优化的支持向量回归机和自适应遗传算法优化的支持向量回归机3种模型的方法,建立了弥苴河水质高锰酸盐含量的的预测模型。通过数据预处理,筛选了60天的数据进行训练学习和测试。通过对三个模型的预测误差分析对比,可以得出自适应遗传算法优化支持向量回归的预测模型精度更高。  相似文献   

10.
支持向量机已经成功应用在许多领域如规则提取、分类和评价。针对阿克苏林果害虫分类种类多的特点,采用了一种简单sift特征提取,结合svm算法分类识别林果主要害虫的方法。首先对样本数据进行SVM分类器训练,从而快速获取原始样本数据的最佳SVM分类器参数,并实现分类。利用神经网络算法进行分类实验,比较分析传统SVM算法、神经网络算法在分类识别方面的差异。实验结果表明,SVM算法能够快速有效地识别害虫种类,并获得相对较高的分类精度,但由于测试图像背景不同且提取的特征单一识别的准确率有待提高。  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号