共查询到20条相似文献，搜索用时 31 毫秒
1.
This paper proposes novel multi-layer neural networks based on Independent Component Analysis for feature extraction of fault
modes. By the use of ICA, invariable features embedded in multi-channel vibration measurements under different operating conditions
(rotating speed and/or load) can be captured together. Thus, stable MLP classifiers insensitive to the variation of operation
conditions are constructed. The successful results achieved by selected experiments indicate great potential of ICA in health
condition monitoring of rotating machines.
Project supported by the National Natural Science Foundation (No. 50205025) and the Natural Science Foundation of Zhejiang
Province (No. 5001004). 相似文献
2.
针对常见的基于PCA的人脸识别方法在识别过程中所遇到的计算量大、分类特征不佳等问题,提出了基于遗传算法的PCA+2DPCA的人脸识别方法,并通过实验,利用ORL人脸数据库验证了该方法的可行性。 相似文献
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教学分析研究现状之思考 总被引：2，自引：1，他引：1
由于教学分析对教学设计、教学评价、教师教学反思等有着显著的现实意义,教学分析的研究正在受着各国教育研究者的广泛关注,各种教学分析理论和方法层出不穷。该文对要素分析、交互分析、基于建模的教学系统分析这三种具有代表性的教学分析理论进行了分析和比较,以期帮助人们深入理解教学分析的各种理论,并为人们预测教学分析发展趋势提供一定的思路。 相似文献
5.
林泽阳 《宁波职业技术学院学报》2012,(5):24-28
主成分分析是一种重要的多元统计分析方法,其广泛应用于自然科学和社会科学的研究中。主成分分析运算过程较复杂,一般需要借助于统计软件来实现。如果手工运算不但计算量大,而且容易出错。文章利用EXCEL中的相关函数,给出了一种实现主成分分析的EXCEL简便算法。 相似文献
6.
本通过对致密夸克物质体粘滞的研究，发现奇异夸克物质体粘滞系数比相应核物质大2～3个量级，从而推得脉冲星旋转可达500～700Hz。这与观测数据很好地相符，说明脉冲星本质上可能是夸克星或包含夸克物质的中子星。 相似文献
7.
陈怡 《黄石理工学院学报(人文社科版)》2011,(6):16-21,25
文章收集了近30年中国水泥产业的数据,以科学发展观为指导,运用主成分分析法,基于中国水泥工业的发展现状对中国水泥行业可持续发展进行了实证研究,指出了中国水泥行业可持续发展的途径。 相似文献
8.
研究了SOA的基本概念和体系结构,分析了将Web Service作为SOA实现技术的不足之处,阐明了SCA/SDO编程模型的优势,并针对高校信息化建设的现状,提出了基于SCA/SDO编程模型,对高校信息系统进行集成的SOA架构模型。 相似文献
9.
本文阐述了因子分析的基本原理,并借助统计分析软件SAS对世界汽车产业的发展状况进行了数量分析。其中对各因子的经济意义作了详细解释,并在此基础上得出各国发展水平评估的综合排名,同时对国家的汽车产业状况进行了综合评价。 相似文献
10.
To evaluate the performance of newly designed electro-pneumatic valves （EPVs） for the air-powered engine （APE） and study laws of parameters affecting them, a simulation model was established based on the thermodynamics and mechanics theories. Experiments were set up to determine the instantaneous effective orifice area of solenoid valve by the constant volume discharge method. The simulation model was also validated by comparing the measured displacement curve with the simulated displacement curve of the valve in the pressure of 0.16 and 0.49 MPa. Simulation and experimental results showed that maximum working frequency of the designed EPV could reach 30 Hz corresponding to 2000 r/min of engine rotating speed. Based on simulation results, impacts of temperature and pressure of control air on delay time, full opening/closing time and seating velocity of EPV were analyzed. The simulation model could also act as EPV simulation prototype in designing the air exchange control system of APE. 相似文献
11.
This paper proposes a current control scheme for a grid-connected pulse width modulator （PWM） voltage source converter （GC-VSC） under imbalanced and distorted supply voltage conditions. The control scheme is implemented in the positive synchronously rotating reference frame and composed of a single proportional integral （PI） regulator and multi-frequency resonant controllers tuned at the frequencies of 2ω and 6ω, respectively. The experimental results, with the target of eliminating the active power oscillations and current harmonics on a prototype GC-VSC system, validate the feasibility of the proposed current control scheme during supply voltage imbalance and distortion. 相似文献
12.
圆度误差的快速傅立叶变换分析 总被引：1，自引：0，他引：1
回转零件正截面轮廓的圆度误差可以视为周期函数。对正截面轮廓等角度间隔采样获得的数据点,可进行离散傅立叶变换(DFT)。通过对数据点序列的快速傅立叶变换(FFT)结果加以分析,可以发现隐藏在圆度误差信号中的各种频率成分。文章首先简要介绍了圆度误差的数学模型,然后分析了各种频率成分对圆度误差的影响。最后提出了圆度误差计算的新方法。 相似文献
13.
旅游低碳经济对海南旅游业可持续发展、海南旅游竞争力提升至关重要。构建海南旅游低碳经济发展指标体系后,采用主成分分析法,找到影响旅游低碳经济的关键因素,并对各市县旅游低碳经济发展水平评价、定位,针对这些因素及各市县发展程度提出建议:提升旅游接待能力;注重环境保护;推动第一、二产业发展;推行环保举措等。 相似文献
14.
校园地理信息系统的构建 总被引：2，自引：0，他引：2
为实现校园地理信息系统的构建,将地理信息系统的控件应用到可视化的编程环境中,进行GIS的二次开放,实现对校园资源的地理分布的空间特征以及校园资源属性特征的综合管理,系统数据库以Access进行管理,在VC＋＋环境下开发前端应用平台,利用ADO动态数据连接引擎实现数据通信;利用MapX组件技术,采用嵌入式集成方式,实现空间分析、查询等专业应用与基本地理信息功能的有机集成． 相似文献
15.
提出了一种两阶段多功能光伏逆变器(QMFI),有功功率借助于该结构可以在一个功率转换器内从光伏阵列直接传输到电网或负载,从而提高转换效率。此外,考虑QMFI最大功率点跟踪(MPPT)的实现和非有功电流的补偿,提出了QMFI的数学模型,从而获得有效的控制参数。在求解过程中,采用基于旋转坐标系的分析模型,并推导了QMFI的空间矢量脉冲宽度调制策略,直观地揭示了非有功电流补偿对两阶段有功潮流的影响。最后,通过3 kVA样机验证了所提方案的可行性和有效性。 相似文献
16.
农民离村问题是一直困扰近代中国的一大社会问题,并引起了社会各方面的重视。其产生原因有深刻的历史背景和现实因素,本文采用主成分分析方法,通过构建一个包括6个方面共17项的指标体系,利用SPSS软件对民国时期全国22个省的农民离村原因进行了数量分析,分析结果显示导致这一问题的主要因子依其重要程度分别是:经济崩溃、自然灾害、人口过密、市场衰落、农民收入低落以及政府管理缺陷因子。 相似文献
17.
Liu GF Zhou HK Hu H Zhu ZH Hayat Y Xu HM Yang J 《Journal of Zhejiang University. Science. B》2007,8(12):860-866
Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, including stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A),dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW. 相似文献
18.
本文从教学设置、教学态度、教学能力、教学结果等因素,设计了评价高等数学教学质量的调查问卷,抽取了苏州科技学院2009级13个专业高等数学教学评价相关原始数据,运用Matlab软件,利用主成分分析建立高等数学教学质量评价模型.并运用数据对高等数学教学质量进行实证检验,结果表明该模型稳定性较好,对开展有效的高等数学质量评价有一定的指导意义. 相似文献
19.
陶敏 《山西财经大学学报(高等教育版)》2011,(3):21-26
《国家中长期人才发展规划纲要（2010～2020年）》强调要实施企业经营管理人才素质提升工程。文章系统地归纳了管理类硕士学位点建设目标,从师资队伍、学科平台、科学研究、人才培养、条件建设、学术交流六个方面,构建了包含39个二级指标的管理类硕士学位点建设水平评价指标体系,并确定二级指标的当量系数和一级指标体系的权重向量,建立基于协调分析方法的评价模型,从优点与缺点两个方面综合评价学位点建设水平,以期通过对管理类硕士学位点建设水平的评价促进管理类硕士学位点的建设,达到提升企业经营管理人才素质的目的。 相似文献
20.
Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, in- cluding stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A), dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW. 相似文献