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基于模糊理论、统计分析等数学理论,提出一种定量的综合国力模糊综合评价模型.首先对基本数据进行标准化处理和主成分分析,并建立综合国力评判集;其次,根据所选取的主成分及其贡献值建立评判对象因素集,并计算综合国力评判因素权向量;最后,利用综合国力评判集、评判因素权向量及评判对象因素集进行模糊综合评判,根据模糊综合评判模型对13个主要国家的综合国力进行了比较分析. 相似文献
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区域城市化水平地域差异及影响因素的灰色关联分析--以湖北省为例 总被引:8,自引:0,他引:8
将湖北省近16年的城市化发展分为两个时段,从人口、社会经济、地理环境等角度选取具有代表性指标,构建评价指标体系并利用主成分分析方法提取城市化水平分异的主因子。在此基础上,利用灰色关联分析方法分析了两个时段湖北省区域城市化水平差异的主要影响因素,其分析结果表明:湖北省区域城市化水平总体上和该区的社会经济发展水平密切相关,但不同时段影响湖北省区域城市化水平分异的主要因素是不同的。在1994年以前的10年内,社会投资能力、市场发育状况及工业化水平是湖北省城市化水平地区分异的最为重要的因素;在1995年后,乡镇工业的发展水平对各区城市化水平差异的影响表现得更为明显。 相似文献
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《干旱区地理》2016,(4)
城市是国家的重要组成部分,在经济全球化的背景下城市的竞争力对于提升国家的综合竞争力扮演着越来越重要的角色。以四川省18个地级市城市竞争力的评价指标体系,运用主成分分析方法和主成分TOPSIS法比较评价了1996年、2000年、2006年和2013年四川省各地级市的城市竞争力,主成分分析方法更接近于四川省城市竞争力的实际情况;利用主成分分析方法进一步分析了各主成分因子对城市竞争力的影响度,研究了城市竞争力的时间演变。依据城市竞争力的综合得分值和利用GIS9.3软件,得到了四川省城市竞争力的等级分布图和反距离权重插值效果图,揭示了城市竞争力在4个时间断面上的空间分异和空间扩展的特征与演变规律。通过对研究区影响城市竞争力各因素的分析及其正确评价,有利于对城市进行正确定位和长期发展规划,实现城市科学发展。 相似文献
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为明确政府行为对河南省城镇化干预力度的强弱,寻找政府干预与城镇化之间的关系以及改革开放以来政府干预城镇化的变化趋势,综合考虑多方面因素共选取11项指标,使用sPss软件对河南省1978-12006年的数据进行了主成分分析和回归分析.从分析结果可以清楚地看到,河南城镇化进程中的政府干预度总体呈下降趋势,1978-2006年问在市场因素逐渐发育并加速发展的情况下,城镇化率与政府干预度成负相关.根据结果,改革开放以来河南省城镇化进程中的政策变迁可划分为3个阶段:(1)1978-1986年城镇化政策由压制转为推动;(2)1987-1996年城镇化政策在探索中改革;(3)1997-2006年政府与市场共同推进城镇化. 相似文献
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径流预测为流域水资源的合理开发利用与统筹配置提供依据。运用多元线性回归、主成分回归、BP神经网络及主成分分析和BP神经网络相结合的方法,对新疆呼图壁河流域石门水文站2009-2011年各月径流量进行预测,并采用相关系数、确定性系数及均方根误差对各模型预测精度进行比较。结果表明:(1)神经网络等智能算法具有高速寻优的能力,对短时间尺度的月径流量的预测结果较好;(2)主成分回归等常规算法能充分反映出某地区径流的年际的稳定性,对全年径流总量的模拟精度较高;(3)主成分分析和BP神经网络相结合的方法,提高了神经网络的收敛速度,同时降低了局部极值的影响,优于简单的BP神经网络,适用于呼图壁河月径流量预测。 相似文献
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为了认知影响须浮鸥(Chlidonias hybridus)营巢的主要环境因素,于2011年6~7月,采用直接观察法和样方法在大庆龙凤湿地自然保护区内对须浮鸥的巢区进行了调查研究.在本次调查中共发现须浮鸥巢73个,逐巢进行了常规测量,并对须浮鸥巢址及附近无巢对照区域的生境进行了调查.主成分分析和独立样本t检验的结果表明,须浮鸥属于集群营巢,而影响须浮鸥巢址选择的主要因素依次为巢下水深、巢距植物距离、巢周明水面积、植物高度、植物密度和巢距干扰源距离.其中,前3个因素影响须浮鸥生境中食物的供给条件,后3个因素影响须浮鸥巢的隐蔽条件.须浮鸥选择巢址的条件是能提供丰富食物且具有较好隐蔽条件的生境. 相似文献
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Two approximate methods for weighted principal components analysis (WPCA) were devised and testedin numerical experiments using either empirical variances (obtained from replicated data) or assumedvariances (derived from unreplicated data). In the first ('spherical') approximation each data vector wasassigned a weight proportional to the geometrical mean of its variances in all dimensions. Thearithmetical mean of variances was used instead in the other approximation. Both the numericalexperiments with artificial data containing random errors of various kinds (constant, proportional,constant plus proportional, Poisson) and the analysis of two sets of Raman spectra clearly indicated thenecessity of introducing statistical weights. The spherical approximation was found to be slightly betterthan the arithmetical one. The application of statistical weighting was found to improve the performanceof PCA in estimation problems. 相似文献
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Calvin A. Whealton Jery R. Stedinger Jared D. Smith Teresa E. Jordan Franklin G. Horowitz Maria C. Richards 《International journal of geographical information science》2020,34(10):2053-2076
ABSTRACT The focus of this work is general methods for prioritization or screening of project sites based on the favorability of multiple spatial criteria. We present a threshold-based transformation of each underlying spatial favorability factor into a continuous scale with a common favorability interpretation across all criteria. We compare several methods of computing site favorability and propagating uncertainty from the data to the favorability metrics. Including uncertainty allows decision makers to determine if seeming differences among sites are significant. We address uncertainty using Taylor series approximations and analytical distributions, which are compared to computationally intensive Monte Carlo simulations. Our methods are applied to siting direct-use geothermal energy projects in the Appalachian Basin, where our knowledge about any particular site is limited, yet sufficient data exist to estimate favorability. We consider four factors that contribute to site favorability: the thermal resource described by the depth to 80°C rock, natural reservoir productivity described by rock permeability and thickness, potential for induced seismicity, and the estimated cost of surface infrastructure for heat distribution. Those factors are combined in three ways. We develop favorability uncertainty propagation and sensitivity analysis methods. All methods are general and can be applied to other multi-criteria spatial screening problems. 相似文献
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EDMUND R.MALINOWSKI 《地理学报(英文版)》1988,(1)
Fisher variance ratio tests are developed for determining(1)the number of statistically significantabstract factors responsible for a data matrix and(2)the significance of target vectors projected into theabstract factor space.F-tests,developed from the viewpoint of vector distributions,are applied tovarious data sets taken from the chemical literature. 相似文献
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本文首先介绍了基于国际粮食贸易的国际主要粮食价格测定方法,并用EVIEW 软件对国际主要粮食价格数据进行数据分离,在此基础上,采用谱分析法和数理统计方法分析了1961-2009 国际主要粮食价格的时间特征,总结和分析了国际主要粮食价格变化的趋势性、周期性和波动性特征。结果表明:①国际主要粮食价格趋势性明显,随时间呈现上涨趋势;②在多种因素的影响下,国际主要粮食价格存在着多周期性。③随着全球一体化和粮食金融化趋势的不断加强,国际主要粮食
价格不稳定性也越来越强。本文研究结果对于进一步分析国际粮食价格机制有一定的参考价值。 相似文献
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We address the problem of estimating the spherical-harmonic power spectrum of a statistically isotropic scalar signal from noise-contaminated data on a region of the unit sphere. Three different methods of spectral estimation are considered: (i) the spherical analogue of the one-dimensional (1-D) periodogram, (ii) the maximum-likelihood method and (iii) a spherical analogue of the 1-D multitaper method. The periodogram exhibits strong spectral leakage, especially for small regions of area A ≪ 4π , and is generally unsuitable for spherical spectral analysis applications, just as it is in 1-D. The maximum-likelihood method is particularly useful in the case of nearly-whole-sphere coverage, A ≈ 4π , and has been widely used in cosmology to estimate the spectrum of the cosmic microwave background radiation from spacecraft observations. The spherical multitaper method affords easy control over the fundamental trade-off between spectral resolution and variance, and is easily implemented regardless of the region size, requiring neither non-linear iteration nor large-scale matrix inversion. As a result, the method is ideally suited for most applications in geophysics, geodesy or planetary science, where the objective is to obtain a spatially localized estimate of the spectrum of a signal from noisy data within a pre-selected and typically small region. 相似文献
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基于科学引文索引数据库SCI-E, 检索获得2010—2014年美国海洋学研究型文献9 702篇, 在确定文献集中词频不低于40的54个高频关键词基础上, 运用共词分析法, 以SPSS 20.0为工具, 探索美国近5年海洋学研究热点。结果表明, 2010—2014年间美国海洋学研究热点集中在6大主题领域: 海洋环流动力学研究、海洋灾害研究、科学技术和方法在海洋中的应用研究、海洋初级生产力研究、海洋污染研究、海洋生物多样性研究。在此基础上, 运用社会网络分析法, 借助可视化工具Ucinet, 对6大研究主题和高频作者共现矩阵进行可视化, 揭示出各研究主题的作者团体。 相似文献
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ROBERT R.MEGLEN Department of Chemistry Laboratory for Chemometrics University of Colorado at Denver PO Box Denver CO - U.S.A. 《地理学报(英文版)》1991,(3)
Principal component analysis is used to examine large multivariate databases.The graphical approachto exploratory data analysis is described and illustrated with a single example of chemical compositiondata obtained on environmental dust particles.While the graphical approach to exploratory data analysishas certain advantages over the numerical procedures,the empirical approach described here should beviewed as complementary to the more robust treatments that statistical methodologies afford. 相似文献
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WINDOW FACTOR ANALYSIS:THEORETICAL DERIVATION AND APPLICATION TO FLOW INJECTION ANALYSIS DATA 总被引:1,自引:0,他引:1
EDMUND R.MALINOWSKI 《地理学报(英文版)》1992,(1)
Window factor analysis(WFA)is a self-modeling method for extracting the concentration profiles ofindividual components from evolutionary processes such as flow injection,chromatography,titrationsand reaction kinetics.The method takes advantage of the fact that each component lies in a specificregion along the evolutionary axis,called the‘window’.Theoretical equations are derived.The methodis used to extract the concentration profiles and spectra of seven bismuth species from data obtained byGemperline and Hamilton,who injected bismuth perchlorate into a flowing stream of hydrochloric acid. 相似文献
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Images can contain chemical information and many chemical methods can generate image data. For anefficient extraction of chemical data from images, data analysis techniques are necessary, It is a greatadvantage to be able to work on multivariate images. Many imaging techniques allow the extraction ofchemical information. Inorganic analytical chemistry seems to have the longest tradition here, butorganic chemistry and biochemistry may soon be catching up. Also large data arrays from non-imagingtechniques can be combined with image analysis in a useful way, provided certain conditions are fulfilled. 相似文献