An agent-integrated irregular automata model of urban land-use dynamics

Urban growth models are useful tools to understand the patterns and processes of urbanization. In recent years, the bottom-up approach of geo-computation, such as cellular automata and agent-based modeling, is commonly used to simulate urban land-use dynamics. This study has developed an integrated model of urban growth called agent-integrated irregular automata (AIIA) by using vector geographic information system environment (i.e. both the data model and operations). The model was tested for the city of San Marcos, Texas to simulate two scenarios of urban growth. Specifically, the study aimed to answer whether incorporating commercial, industrial and institutional agents in the model and using social theories (e.g. utility functions) improves the conventional urban growth modeling. By validating against empirical land-use data, the results suggest that a holistic framework such as AIIA performs better than the existing irregular-automata-based urban growth modeling.     

基于指标规范值的海水水质评价的SVR模型

为了建立具有普适通用的海水水质评价的支持向量机模型,在设置各指标参照值和指标规范变换式,并对指标进行规范变换的基础上,应用免疫进化优化算法,建立基于指标规范值的海水水质评价的回归支持向量机模型。将优化好的模型用于珠江口海水水质的评价,其评价结果与BP神经网络的评价结果基本一致,从而表明基于指标规范值的支持向量机模型用于海水水质评价是可行的,且该模型较传统的支持向量机评价模型具有较好的普适性和通用性。     

Aerosol Type Identification Using PARASOL Multichannel Polarized Data

PARASOL （Polarization ＆ Anisotropy of Reflectances for Atmospheric Sciences coupled with Ob- servations from a Lidar） multi-channel and mul- ti-directional polarized data for different aerosol types were compared. The PARASOL polarized radiance data at 490 nm, 670 nm, and 865 nm increased with aerosol optical thickness （AOT） for fine-mode aerosols; however, the polarized radiances at 490 nm and 670 nm decreased as AOT increased for coarse dust aerosols. Thus, the vari- ation of the polarized radiance with AOT can be used to identify fine or coarse particle-dominated aerosols. Polar- ized radiances at three wavelengths for fine- and coarse-mode aerosols were analyzed and fitted by linear regression. The slope of the line for 670 nm and 490 nm wavelength pairs is less than 0.35 for dust aerosols. However, the value for fine-mode aerosols is greater than 0.60. The Support Vector Machine method （SVM） based on 12 vector features was used to discriminate clear sky, coarse dust aerosols, fine-mode aerosols, and cloud. Two cases were given and validated by AErosol RObotic NETwork （AERONET） measurements, MODIS （Mod- erate Resolution Imaging Spectroradiometer） FMF （Fine Mode Fraction at 550 nm） images, PARASOL RGB （Red Green Blue） images, and CALIOP （Cloud-Aerosol Lidar with Orthogonal Polarization） VFM （Vertical Feature Mask） data.     

海底双相随机介质声反射的SVM神经网络分类识别研究

考虑海底沉积介质为双相介质,为了更好地模拟实际海底底质的不均匀性,将随机介质理论引入双相介质理论。首先,通过基于随机-双相介质理论的高阶有限差分数值技术模拟计算海底底质分别为泥质砂、泥、泥质砾时的地震反射波信号。然后利用小波变换分别求取不同底质的一次反射波的包络作为其特征向量,最后利用基于粒子群智能算法优化的支持向量机神经网络对这些反射波信号进行分类识别。为了进一步考察所用方法的抗噪能力,对正演得到的海底底质反射波信号分别加入10%、30%、50%的高斯白噪音之后再进行分类,支持向量机仍然取得了较好的分类预测效果。基于上述正演模拟及分类识别方法的论证,提出了一套行之有效的微机软件模拟海底沉积物分类识别的一般化流程,这将有利于开展海底沉积物反射特征的进一步研究。     

基于三维荧光光谱-平行因子技术联用的浮游藻化学分类学技术研究

An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis(PARAFAC) and CHEMTAX. The PARAFAC model was applied to fluorescence excitation-emission matrix(EEM) of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis(BDA). Then the reference fluorescent component ratio matrix was constructed for CHEMTAX, and the EEM–PARAFAC–CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios(CDRs) when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacillariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ.     

Nonlinear optimization method of ship floating condition calculation in wave based on vector

Ship floating condition in regular waves is calculated. New equations controlling any ship＇s floating condition are proposed by use of the vector operation. This form is a nonlinear optimization problem which can be solved using the penalty function method with constant coefficients. And the solving process is accelerated by dichotomy. During the solving process, the ship＇s displacement and buoyant centre have been calculated by the integration of the ship surface according to the waterline. The ship surface is described using an accumulative chord length theory in order to determine the displacement, the buoyancy center and the waterline. The draught forming the waterline at each station can be found out by calculating the intersection of the ship surface and the wave surface. The results of an example indicate that this method is exact and efficient. It can calculate the ship floating condition in regular waves as well as simplify the calculation and improve the computational efficiency and the precision of results.     

天宫一号高光谱数据辐射校正的CUDA并行优化

高光谱图像经过辐射校正后,消除了探测元的响应差异,能更好地满足专题信息提取的数据要求.利用探测元的列均值、列标准差等统计信息对天宫一号高光谱短波红外数据进行辐射校正检验,并基于GPU CUDA计算模型对均值归一化、矩匹配、相邻列均衡等3种相对辐射校正算法进行了并行计算优化.通过辐射校正计算流程拆分,CPU控制流程逻辑,GPU执行数据级并行计算,并建立CUDA的计算单元与数据单元的映射关系,获得5—7倍的计算加速比,这些辐射校正算法依据图像自身统计信息,且易于进行并行计算优化,满足实时校正的处理时效要求,为未来高光谱数据在轨实时辐射校正提供了新思路.     

时空遥感云计算平台PIE-Engine Studio的研究与应用

随着遥感大数据时代的到来,为快速处理和分析海量遥感数据,国内外涌现了众多遥感云计算平台,使得全球尺度、长时间序列遥感数据的快速分析和应用成为可能。本文在分析国内外遥感云计算平台现状的基础上,针对大数据时代国内缺少功能完备的遥感云计算平台,且国外遥感云计算平台对国产卫星数据支持不足等问题,基于容器云技术,构建了包含国产卫星数据且集数据、算力和技术于一体的时空遥感云计算平台PIE（Pixel Information Expert）-Engine Studio,实现了脚本驱动的遥感数据的按需获取以及海量数据的快速处理。采用Landsat 8数据,以生长季植被指数NDVI（Normalized Difference Vegetation Index）的计算为例,对比了本平台与GEE（Google Earth Engine）的数据处理能力。结果表明,由于计算资源的限制,本平台的计算和导出时间均比GEE稍长,但计算结果的空间分布一致,其中近68%的值均分布在（0.48,0.77）,且二者差值的95.33%集中在（-0.13,0.13）,结果较为可信。因此,本文构建的基于共享、开放的中国自主遥感云计算平台PIE-Engine Studio,可为地球科学领域的研究提供数据和算力支持,将有助于推进中国遥感云计算平台的发展进程,推动国产卫星数据在云计算平台上的应用。     

沉积岩平行层面与垂直层面方向热导率与孔隙连通性之间的关系

根据对渤海湾盆地沾化凹陷泥质岩、粉砂岩、砂岩和白云岩平行层面与垂直层面方向热导率差异及孔隙连通性差异特征的研究,探讨了沉积岩平行层面与垂直层面方向热导率与孔隙连通性之间的关系。热导率实验结果表明:沾化凹陷泥质岩、粉砂岩和砂岩的平行层面方向热导率大于垂直层面方向热导率;白云岩的平行层面方向热导率小于垂直层面方向热导率。沉积岩平行层面与垂直层面方向热导率差异和孔隙连通性差异之间具有正相关性。孔隙特征分析结果表明:孔隙连通性较好方向,热导率也较高;孔隙连通性较差的的方向,热导率也较低。     

Structural analysis of the Lombard thrust sheet and adjacent areas in the Helena salient,southwest Montana,USA

The Helena salient is a prominent craton–convex curve in the Cordillera thrust belt of Montana, USA. The Lombard thrust sheet is the primary sheet in the salient. Structural analysis of fold trends, cleavage attitudes, and movement on minor faults is used to better understand both the geometry of the Lombard thrust and the kinematic development of the salient.Early W–E to WNW–ENE shortening directions in the Lombard sheet are indicated by fold trends in the center of the thrust sheet. The same narrow range of shortening directions is inferred from kinematic analysis of movement on minor faults and the orientations of unrotated cleavage planes along the southern lateral ramp boundary of the salient. As the salient developed, the amount and direction of shortening were locally modified as listric detachment faults rotated some tight folds to the NW, and as right-lateral simple shear, caused by lock-up and folding of the Jefferson Canyon fault above the lateral ramp, rotated other folds northeastward. Where the lateral ramp and frontal-oblique ramp intersect, folds were rotated back to the NW. Our interpretation of dominant W–E to WNW–ESE shortening in the Lombard sheet, later altered by local rotations, supports a model of salient formation by primary parallel transport modified by interactions with a lateral ramp.