基于正交实验的BP神经网络预测研究

用不同的L9(34)正交实验方案结果作为训练学习样本集，对BP神经网络预测应用过程的策略进行了探讨，结果表明：完备的正交实验样本集是基本训练学习单元，在完备的正交实验样本集上添加或减少样本数量，所预测的结果是不可靠的；在同一类型、同一实验的条件下，完备的信息量大的正交实验样本集，能以很高的精度预测完备的信息量小的正交实验样本集；提出了一条新的实验设计思路——通过实验得出一个完备的正交实验样本集，通过计算机用BP神经网络就可以把与已知样本集有相同影响因素和水平的所有样本的值以相当高的精度预测出来，从而大大节省时间和劳力。     

用支持向量机检测乳腺X线影像中的结构扭曲

利用频域小波变换对乳腺X线影像中结构扭曲的图像进行小波分解,从得到的分解图像中计算了12个与纹理有关的特征参数.用支持向量机分类算法对样本集2组实验对象(乳腺结构扭曲、正常样本各19个)进行乳腺结构扭曲的识别分类;通过优化支持向量机参数条件,得到最好的分类结果.分类结果表明:本研究确定的12个纹理特征参数组合,用优化的支持向量机分类器检测和识别乳腺结构扭曲,分类正确率为92.1%、灵敏度89.5%和特异度94.7%.     

基于改进MFCC的异常声音识别算法

在声音识别系统中,特征参数的获取对声音识别和训练有着重要的影响;MFCC算法作为典型的声音特征参数提取方法,性能稳定,识别率高;针对MFCC算法存在较大计算量的情况,提出一种改进的特征参数提取算法MFCC_E;相比于标准的MFCC算法,MFCC_E算法减少了约50%的运算量,并且易于硬件实现;实验结果表明,MFCC_E算法与MFCC算法的识别率大致相同,而计算复杂度却小很多。     

实验室制备乙烯实验的研究和改进

目前实验室制乙烯大多数采用浓硫酸和乙醇为原料制取,该实验存在的主要问题是;在反应过程中,瓶内反应物逐渐变黑,最终形成大量炭渣,使乙烯产率较低;反应结束清洗反应瓶时,瓶内会散发出很浓的二氧化硫气味及其它难闻的气体,污染空气,有碍健康.本实验用浓硫酸、浓磷酸、大理石和乙醇为原料,采用正交实验设计法来安排实验,并利用正交表的特点对实验结果进行计算、分析,最终得出制备乙烯的最佳原料配比.按最佳配比做验证实验后得出谈实验具有药品便宜易得、耗时短、产率高、炭化程度小等许多优点.比目前用其他方法制乙烯效果好.     

基于MFCC与CHMM的方向指令语音识别

随着科学技术尤其是计算机技术的不断发展,语音识别被广泛应用到各个领域.针对方向指令的语音,使用梅尔倒谱系数(Mel-Frequency Cepstrum Coefficient,MFCC)作为特征参数,连续马尔科夫模型(Continuous Hidden Markov Model,CHMM)作为识别模型,对语音信号进行识别处理.实验结果显示,此方法在方向指令语音识别中取得了良好的结果,有较高的识别准确率.     

圆柱齿轮弯曲应力数值模拟与影响因素分析

以直齿圆柱齿轮为研究对象,首先利用ANSYS有限元软件建立模型,对齿轮弯曲应力进行数值模拟。然后采用正交实验设计方法设计实验,通过直观和方差分析方法研究齿宽、齿数、扭矩对弯曲应力的影响。最后利用多元线性回归原理建立齿轮弯曲应力数学模型。结果表明,ANSYS数值模拟所得的齿轮弯曲应力与传统理论公式计算结果接近,说明仿真实验可信。在正交实验设计中,扭矩的极差最大,即对齿轮弯曲应力的影响最大,齿数次之,齿宽对齿轮弯曲应力的影响程度最小,可忽略不计。计算结果验证了回归方程的可靠性。该研究为变速器齿轮传动装置设计提供了有益参考。     

基于一种新特征参数的说话人识别

针对传统的特征参数Mel频域倒谱系数MFCC难以满足语音信号的非平稳性问题,提出一种基于小波分析的新特征参数FPBW的提取方法.为了提高训练速度,采用正交高斯混和模型,将正交变换改到最大期望EM算法之前进行,从而减少训练时间.实验结果表明,新的特征参数FPBW优于特征参数MFCC,并且采用正交高斯混合模型进一步提高了识别性能和训练速度.     

基于Haar特征的中文车牌识别系统

提出了一种基于Haar特征的车牌识别方案,利用Haar特征可靠性高、计算复杂性低和容错性强等方面的特点,能够对含有噪声的中文车牌图像快速准确识别,并在Python和OpenCV开源环境下设计和实现了该方案。实验结果证明该方案具有识别率较高(94%)、识别时间短(单字符低于0.02 s,全车牌低于0.63 s)和鲁棒性强等特点,可应用于实际智能交通控制。     

大学物理设计性实验教学的探讨

大学物理设计性实验是在学生掌握基础性实验后，具备一定的综合实验基础知识及其能力之后进行的一种教学实践活动；大学物理设计性实验最关键是实验设计和实验方案的选择。分析了大学物理设计性实验特点，研究了实验程序，提出了实验方案和选择原则。     

B超图象的纹理识别

根据肝脏B超图象的特点 ,提出利用分形特征配以和差直方图提取特征参数进行纹理识别 ,实验结果表明 :该方法分类精度高且计算速度快 ,克服了它们各自作为特征对肝脏B超图象进行纹理识别时 ,其识别率较低的缺点     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.