浙江省市域旅游竞争力评价研究

通过构建市域（地级市）尺度旅游竞争力评价体系,应用主成分分析方法,对浙江省市域旅游竞争力进行定量评价,得到11个地市旅游竞争力综合指标得分和排名,并根据评价结果对其差异格局形成原因进行深度剖析。结果表明,浙江省市域旅游竞争力水平整体差异较大,表现为区域旅游业发展不平衡,杭州、宁波双核格局明显,温州、绍兴为竞争力较强市,金华、舟山、台州、湖州竞争力较弱,丽水、嘉兴、衢州为弱竞争力市。各地区旅游业发展应避开其竞争力薄弱环节,走差异化发展道路。     

基于径向基函数神经网络的混合像元分解

遥感图像中普通存在着混合像元。对这部分像元进行分类（即混合像元分解）是遥感图像处理中的难点。基于主分量分析的混合像元分解 法是一种较为成熟的算法，但它存在着计算量大，适应性差等缺点。在深入研究混合像元分解原理的基础上，提出了用径向基函数神经网络拟合分解结果超平面，以实现混合像元分解的算法，实验结果证明：该算法的结果与基于主分量分析的混合像元分解算法结果相近（相关系数达到0．00），而计算量大大减少，具有较强的适应性。     

珠江流域4～9月降水空间分布特征和类型

利用美国CAPS的非静力高分辨率区域预报模式ARPS(先进区域预报系统)对0414号台风"云娜"进行数值模拟,模拟结果表明ARPS较好地模拟台风"云娜"的移动路径及台风大暴雨.并着重讨论新一代天气雷达资料对台风"云娜"数值模拟的影响,通过对雷达资料同化进模式与没有雷达资料同化进模式对比模拟的试验结果分析表明:雷达资料进模式,对中高层的风场调整,改进对台风细微结构特征描述,加大近台风中心南侧的西风分量和近台风中心西侧的北风分量,从而改进云娜台风登陆后西行移动路径预报;对扰动温度、雨水混合率、云水混合率及水汽混合率场等调整,改善模式初始场台风中高层成雨条件,对台风降水预报,尤其暴雨的落区、降水分布及其随时间变化的预报有较大改进.     

近44年云南年平均气温的时空变化特征

利用云南省121个地面测站1961-2004年的年平均气温，分析了云南最近40多年来气温变化的基本特征。在气温的年代变化上，1960年代和1980年代云南气温波动较小，1970年代是近44年来最冷的一个年代，1990年代以后逐步转暖，但1990年代的年平均气温波动也较大。各地不同时段具有不同的气温倾向率，1980年代以来全省平均气温倾向率为0．24℃／10年，与全国大部地区的升温率接近，滇西的保山、中甸和思茅等地是近40年全省升温最快的地区，而滇中地区则是最近10多年全省升温最显著的地区。主分量分析揭示了云南各地气温变化的时空分布特征，第1特征向量场的高值区是云南气温变化的敏感区，第1主分量序列是反映云南整体年均气温变化趋势的指标，第2特征向量场的正值区和负值区基本对应第1特征向量的低值区和高值区。在第1特征向量的高值区1960年代以来的气温变化具有前低后高的特点，低值区则相反。     

Separating near surface thermal inertia signals from a thermal time series by standardized principal component analysis

Principal component analysis has been applied to remote sensing data to identify spatiotemporal patterns in a time series of images. Thermal inertia is a surface property that relates well to shallow surface thermal and physical properties. Mapping thermal inertia requires quantifying surface energy balance components and soil heat flux, both of which are difficult to measure remotely. This article describes a method to map soil thermal inertia using principal component analysis applied to a time series of thermal infrared images and it also assesses how sensitive this method is to the time intervals between images. Standardized principal component analysis (SPCA) was applied to thermal infrared images captured at half-hour intervals during a complete diurnal cycle. Shallow surface thermal properties accounted for 45%, 82% and 66% of the spatiotemporal variation in surface temperature observed during the heating phase, cooling phase and over the total diurnal cycle respectively. The remaining 55%, 18% and 34% of the variation was attributed to transient effects such as shadows, surface roughness and background noise. Signals related to thermal inertia explained 18% of total variation observed in a complete diurnal cycle and 7% of variation in the cooling series. The SPCA method was found useful to separate critical information such as timing and amplitude of maximum surface temperature variation from delays related to differential heating induced by micro-topography. For the field conditions experienced in this study, decreased temporal resolution when sampling intervals were greater than an hour significantly reduced the quality of results.     

An assessment of independent component analysis for detection of military targets from hyperspectral images

Hyperspectral data acquired over hundreds of narrow contiguous wavelength bands are extremely suitable for target detection due to their high spectral resolution. Though spectral response of every material is expected to be unique, but in practice, it exhibits variations, which is known as spectral variability. Most target detection algorithms depend on spectral modelling using a priori available target spectra In practice, target spectra is, however, seldom available a priori. Independent component analysis (ICA) is a new evolving technique that aims at finding out components which are statistically independent or as independent as possible. The technique therefore has the potential of being used for target detection applications. A assessment of target detection from hyperspectral images using ICA and other algorithms based on spectral modelling may be of immense interest, since ICA does not require a priori target information. The aim of this paper is, thus, to assess the potential of ICA based algorithm vis a vis other prevailing algorithms for military target detection. Four spectral matching algorithms namely Orthogonal Subspace Projection (OSP), Constrained Energy Minimisation (CEM), Spectral Angle Mapper (SAM) and Spectral Correlation Mapper (SCM), and four anomaly detection algorithms namely OSP anomaly detector (OSPAD), Reed–Xiaoli anomaly detector (RXD), Uniform Target Detector (UTD) and a combination of Reed–Xiaoli anomaly detector and Uniform Target Detector (RXD–UTD) were considered. The experiments were conducted using a set of synthetic and AVIRIS hyperspectral images containing aircrafts as military targets. A comparison of true positive and false positive rates of target detections obtained from ICA and other algorithms plotted on a receiver operating curves (ROC) space indicates the superior performance of the ICA over other algorithms.     

池州市公交查询系统的设计与实现

传统应用型地理信息系统软件开发主要通过商用地理信息系统软件的二次开发语言来实现,造成系统可移植性差、界面不友好、数据库软件不兼容等缺点;池州市公交查询系统采用VB和组件GIS相结合的方法进行开发,一方面利用组件强大的GIS功能,实现池州市公交站点查询、线路查询、公交换乘查询等功能,另一方面利用VB设计出良好的用户界面以...     

二级并行独立成分分析端元提取算法

在多对称处理器集群体系结构下进行独立成分分析并行算法研究,在共享内存模型一级并行算法基础上,通过同步、异步迭代两种方式并行计算固定点函数,分别提出具有两级并行特性的二级同步、二级异步并行端元提取算法,并结合两者的优势,进一步提出二级分组并行算法。实验评价表明,二级同步、分组并行算法在保持原算法精度的同时,大大提高了原算法的效率,体现出良好的并行计算性能,而二级异步并行算法可在节点数较少的情况下适用。     

基于MAP的高光谱影像增强方法

介绍了MAP方法的基本原理,建立了适用于高光谱影像增强的观测模型,给出了模型的代价函数.在假设高光谱影像像点相互独立的条件下,给出了代价函数的求解方法,分析并给出了基于MAP的高光谱影像增强流程.利用PHI高光谱影像及其对应的高分辨率全色影像数据,进行了MAP高光谱影像增强实验.实验结果的定量分析表明,本文方法能够在保...     

Evaluation of three‐dimensional modal pushover analysis for unsymmetric‐plan buildings subjected to two components of ground motion

The accuracy of the three‐dimensional modal pushover analysis (MPA) procedure in estimating seismic demands for unsymmetric‐plan buildings due to two horizontal components of ground motion, simultaneously, is evaluated. Eight low‐and medium‐rise structures were considered. Four intended to represent older buildings were designed according to the 1985 Uniform Building Code, whereas four other designs intended to represent newer buildings were based on the 2006 International Building Code. The median seismic demands for these buildings to 39 two‐component ground motions, scaled to two intensity levels, were computed by MPA and nonlinear response history analysis (RHA), and then compared. Even for these ground motions that deform the buildings significantly into the inelastic range, MPA offers sufficient degree of accuracy. It is demonstrated that PMPA, a variant of the MPA procedure, for nonlinear systems is almost as accurate as the well‐known standard response spectrum analysis procedure is for linear systems. Thus, for practical applications, the PMPA procedure offers an attractive alternative to nonlinear RHA, whereby seismic demands can be estimated directly from the (elastic) design spectrum. In contrast, the nonlinear static procedure specified in the ASCE/SEI 41‐06 Standard is demonstrated to grossly underestimate seismic demands for some of the unsymmetric‐plan buildings considered. Copyright © 2011 John Wiley & Sons, Ltd.