The potential of the MERIS Terrestrial Chlorophyll Index for carbon flux estimation

In this study we evaluated the potential of the Medium Resolution Imaging Spectrometer (MERIS) Terrestrial Chlorophyll Index (MTCI) for monitoring gross primary productivity (GPP) across fifteen eddy covariance towers encompassing a wide variation in North American vegetation composition. The across-site relationship between MTCI and tower GPP was stronger than that between either the MODIS GPP or EVI and tower GPP, suggesting that data from the MERIS sensor can be used as a valid alternative to MODIS for estimating carbon fluxes. Correlations between tower GPP and both vegetation indices (EVI and MTCI) were similar only for deciduous vegetation, indicating that physiologically driven spectral indices, such as the MTCI, may also complement existing structurally-based indices in satellite-based carbon flux modeling efforts.     

基于神经网络的专家系统的应用研究

本文论述了传统专家系统的缺点及神经网络专家系统的功能，并给出了应用实例。     

电动车蓄电池SOC估计的神经网络方法

针对蓄电池荷电状态估计问题,将神经网络方法用于电动车蓄电池荷电状态的估计。依据蓄电池荷电状态与可测量参数之间的非线性关系,建立了基于BP神经网络与RBF神经网络的蓄电池荷电状态预测模型。仿真结果表明,经过训练后的预测模型,可以通过蓄电池的端电压、工作电流以及蓄电池的内阻参数预测蓄电池的实时荷电状态。通过比较,RBF预测模型具有较好的泛化能力且稳定性更强,能够更精确的估计出蓄电池的剩余容量。     

基于神经网络的MIMO-OFDM信道估计

提出了一种适用于神经网络框架下的MIMO-OFDM系统的信道估计算法。通过对三层神经网络结构的分析,用两层神经网络实现了一种主成分分析（PCA）最小二乘学习算法。通过导频信息得到MIMO-OFDM信道模型初始值,再用神经网络算法对MIMO-OFDM信道的时变状态参数进行跟踪;采用两层神经网络,由隐层输出对最终输出修正,中间实现可变遗忘因子的改进递推最小二乘学习算法。仿真结果表明,该方法与最小二乘（LS）算法相比,在跟踪时变衰落信道时,估计的均方误差有较大提高,从而有效地改善了接收端的符号检测性。     

The ESA Medium Resolution Imaging Spectrometer MERIS a review of the instrument and its mission

Following the successful operations of the ERS-1 and 2 satellites which are mainly dedicated to physical oceanography and ice observations from space, the European Space Agency (ESA) developed a multidisciplinary Earth observation instrument within its polar Earth Observation Programme with a focus on biological ocean observations. The Medium Resolution Imaging Spectrometer (MERIS) will be launched onboard Envisat-1 in the 1999-2000 time frame, providing a European remote sensing capability for observing for example oceanic biology and marine water quality through observations of water colour. MERIS will have a medium spectral and high radiometric resolution and a dual spatial resolution, within a global mission, covering open ocean and coastal zone waters, important aspects of the atmosphere, and large ecosystems over land. The global mission of MERIS will have a major contribution to scientific projects aimed at greater understanding of the role of oceans and ocean productivity in the climate system and our ability to forecast change through models. Secondary objectives of the MERIS mission will be directed to the measurement of atmospheric parameters associated with clouds, water vapour and aerosols in addition to land surface parameters, important in particular for the understanding of vegetation processes. In advance of the launch of MERIS, algorithms are being developed for the interpretation of MERIS observations and dedicated studies are ongoing to establish the means of validating the data products. The aim of this paper is to provide a comprehensive overview of the MERIS concept, its mission and data products in context of the driving scientific requirements.     

基于神经网络集成的数据分析

神经网络集成通过训练多个神经网络并将其结论进行适当的合成,可以显著地提高学习系统的泛化能力.然而,设计一个好的神经网络集成必须在个体准确性与彼此差异性之间取得一个平衡.本文提出了一种改进的神经网络集成构造方法--基于噪声传播的神经网络集成算法(NSENN).     

基于粗糙集的神经网络的目标识别应用

在现代防空作战中,如何快速准确的对敌我(友)目标进行识别,至关重要.本文提出先利用粗糙集理论对目标特征属性进行优化筛检,再利用神经网络对目标进行分类识别,该方法不但提高了识别的准确率而且兼顾到识别的效率.试验结果表明,该方法符合现代防空作战中目标识别的要求,具有一定的实用价值.     

小波网络在雷达信号处理中的应用

本文以电子战为背景,在雷达接收机中引入了小波神经网络,研究了系统的结构及自适应均衡算法。仿真结果表明,该算法收敛性能较好,适用于电子战中,雷达信号处理的复杂要求。     

Fuzzy linear regression based on Polynomial Neural Networks

In this study, we introduce an estimation approach to determine the parameters of the fuzzy linear regression model. The analytical solution to estimate the values of the parameters has been studied. The issue of negative spreads of fuzzy linear regression makes the problem to be NP complete. To deal with this problem, an iterative refinement of the model parameters based on the gradient decent optimization has been introduced.In the proposed approach, we use a hierarchical structure which is composed of dynamically accumulated simple nodes based on Polynomial Neural Networks the structure of which is very flexible.In this study, we proposed a new methodology of fuzzy linear regression based on the design method of Polynomial Neural Networks. Polynomial Neural Networks divide the complicated analytical approach to estimate the parameters of fuzzy linear regression into several simple analytic approaches.The fuzzy linear regression is implemented by Polynomial Neural Networks with fuzzy numbers which are formed by exploiting clustering and Particle Swarm Optimization. It is shown that the design strategy produces a model exhibiting sound performance.     

基于量子神经网络的人脸识别技术研究

人脸识别问题是模式识别领域的一个重要的研究课题。提出了一种基于多层激励函数的量子神经网络人脸识别方法,采用ORL人脸图像数据库进行训练和识别。试验结果表明,该识别方法在识别率和可信性方面均有较好的效果,同时也体现了量子神经网络用于人脸识别的优越性和巨大的潜力。     

基于BP神经网络的隐写分析分类器设计

设计并实现了基于BP神经网络的隐写分析分类器。首先对图像库中的图像进行格式变换,并使用扩展修改方向和钻石编码两种隐写方法进行不同嵌入率的隐写嵌入,然后计算载体图像和载密图像中平面域、DCT域和小波域的一些属性值作为特征。利用Matlab的模式识别工具箱搭建BP神经网络,用已知类别的图像特征训练分类器并进行分类测试。实验结果表明,多域综合特征可以实现良好的分类效果,能以较高的准确率识别出载体图像和载密图像。     

概率神经网络方法在岩性识别中的应用

本文研究利用概率神经网络方法进行测井资料的岩性识别;建立了测井解释的岩性识别模型,并利用该模型对测试样本进行预测,预测结果与实际测量结果相比具有较好的一致性,其计算量小且预测精度与收敛速度较BP神经网络模型有了很大的提高;应用表明,概率神经网络在岩性识别问题中有着一定的应用前景。     

基于细胞神经网络的视频分割算法研究

细胞神经网络（CNN）是一种局部互连的非线性并行模拟视觉处理系统,具有适合硬件实现处理速度快的优点,被广泛地应用于图像处理的各个方面。针对目前大多数视频分割算法难以满足实时性要求的缺点,将细胞神经网络应用到视频分割当中．提出了一种改进的基于细胞神经网络的视频分割算法,并通过仿真实验证明了其可行性。     

基于神经网络的智能教学系统学生模型设计

智能性是智能教学系统最重要的特性之一.为提高智能教学系统的智能水平,研究了利用具有较强自学习能力的人工神经网络来构建智能教学系统.从因材施教,准确反映学生学习状态、特征的角度出发,分析了学生学习过程中的影响因素,提出将学生的学习方式、学习习惯等因素纳入学生模型构建中,并对学生模型进行了设计.     

基于神经网络的智能教学系统学生模型设计

智能性是智能教学系统最重要的特性之一。为提高智能教学系统的智能水平,研究了利用具有较强自学习能力的人工神经网络来构建智能教学系统。从因材施教,准确反映学生学习状态、特征的角度出发,分析了学生学习过程中的影响因素,提出将学生的学习方式、学习习惯等因素纳入学生模型构建中,并对学生模型进行了设计。     

基于神经网络与遗传算法的入侵检测研究

入侵检测是一种动态的安全防护技术,能够对网络内部、外部攻击进行防御。采用遗传算法来优化神经网络权值,能很好地避免BP算法的局部极小值,解决了BP算法收敛慢的问题。同时也能解决单独利用遗传算法短时间难以找到最优解的问题。将该算法应用于入侵检测领域中,理论与实验表明该算法具有较好的检测能力。     

基于人工神经网络铂电阻非线性估计方法的研究􀀁

本文提出了一种基于人工神经网络的铂电阻传感器非线性估计方法,该方法用二次幂级数多项式拟合温度传感器的非线性模型,多项式的系数可由神经网络学习算法得到,当条件发生变化时,只要给出几组测量数据对,通过该方法可自动重新训练网络,获得新的多项式系数,实现传感器的非线性估计。     

基于改进BP网络的雷达网抗干扰性能评估

通过分析有源压制干扰环境下雷达网抗干扰性能的评估指标集和BP网络的工作特性,采用改进后的BP网络,把相关的评估指标集映射到BP网络各层之中,得到相应的BP网络评估模型.最后用Matlab神经网络工具箱对该评估模型进行了仿真实验,结果验证了评估模型的正确性及评估方法的可行性.     

Neural network estimation of chlorophyll a from MERIS full resolution data for the coastal waters of Galician rias (NW Spain)

In typical Case 2 waters, accurate remote sensing retrieval of chlorophyll a (chla) is still a challenging task. In this study, focusing on the Galician rias (ΝW Spain), algorithms based on neural network (NN) techniques were developed for the retrieval of chla concentration in optically complex waters, using Medium Resolution Imaging Spectrometer (MERIS) data. There is considerable interest in the accurate estimation of chla for the Galician rias, because of the economic and social importance of the extensive culture of mussels, and the high frequency of harmful algal events. Fifteen MERIS full resolution (FR) cloud-free images paired with in situ chla data (for 2002-2004 and 2006-2008) were used for the development and validation of the NN. The scope of NN was established from the clusters obtained using fuzzy c-mean (FCM) clustering techniques applied to the satellite-derived data. Three different NNs were developed: one including the whole data set, and two others using only points belonging to one of the clusters. The input data for these latter two NNs was chosen depending on the quality level, defined on the basis of quality flags given to each data set. The fitting results were fairly good and proved the capability of the tool to predict chla concentrations in the study area. The best prediction was given for the NN trained with high-quality data using the most abundant cluster data set. The performance parameters in the validation set of this NN were R² = 0.86, mean percentage error (MPE) = − 0.14, root mean square error (RMSE) = 0.75 mg m^− 3, and relative RMSE = 66%. The NN developed in this study detected accurately the peaks of chla, in both training and validation sets. The performance of the Case-2-Regional (C2R) algorithm, routinely used for MERIS data, was also tested and compared with our best performing NN and the sea-truthing data. Results showed that this NN outperformed the C2R, giving much higher R² and lower RMSE values.This study showed that the combination of in situ data and NN technology improved the retrieval of chla in Case 2 waters, and could be used to obtain more accurate chla maps. A local-based algorithm for the chla retrieval from an ocean colour sensor with the characteristics of MERIS would be a great support in the quantitative monitoring and study of harmful algal events in the coastal waters of the Rias Baixas. The limitations and possible improvements of the developed chla algorithms are also discussed.     

基于复合神经网络的学习风格动态分析与研究

近年随着慕课（MOOC）等新兴教育教学手段的快速发展,大量的学习者学习行为可以被系统所记录和分析,从而为个性化教学奠定了重要基础。在Felder-Silverman学习风格模型的理论基础上,通过引入智能分析算法动态地分析和识别学习者学习风格,构建了一套融合了卷积神经网络和循环神经网络的“识别-推理”复合模型,通过学习者的线上学习行为、社区交互行为、学习内容浏览行为、点击拖动行为等学习过程识别其学习行为特征,并使用基于门控循环单元（Gated Recurrent Unit,GRU）的循环神经网络处理和预测其可能的学习风格及对学习内容形式的偏好,以更高效地为学习者提供适应于其学习风格的学习内容和路径,优化学习体验,为大规模、个性化和高质量的下一代学习平台提供技术支撑。