物理场多重分形谱理论模型的数值模拟研究

利用二维双标度三分非空集对物理场多重分形谱进行了理论模型的数值模拟研究。模拟结果表明：随着物理量空间分布不均匀性的增大，不同模型参数下的理论分形谱曲线变陡，Dq值域范围变宽。利用多重分形谱曲线的形态特征，可进一步了解是“稀疏区”还是“密集区”起主导作用，这对于从理论上把握物理和化学场分布特性具有重要意义。     

运用灾害熵浅析沙尘暴强度

以信息熵原理为基础，引入灾害熵概念，评价自然灾害的发生的不确定性和根据各致灾因子的强弱，确定灾害事件的重要性因子，构建灾害信息量计算模型。并以新疆境内达坂城、精河、哈密、吐鲁番、鄯善等五个地区的多年沙尘暴灾害统计数据为研究实例，计算分析了灾害次数、灾害熵。经过分析得出：哈密地区的沙尘暴灾害不仅灾害强度最烈，致灾因子亦最为活跃。通过应用灾害熵及其相应的修正模式，可以定量的确定灾害的影响强度，定性地说明致灾因子的多寡。     

关于熵与城市发展之探讨

城市的形成和发展是一个历史过程，如何评判城市是一个深刻的哲学命题，从熵定律角度来研究城市发展，可以帮助我们建立一种新的城市发展观。城市发展是一个不可逆过程，城市作为一个开放的系统，只要能够从外部环境得到足够的负熵流以抵消内部的熵增，城市将形成耗散结构系统并朝着进化的方向发展。未来的城市应进入低熵社会，主要途径是：建立生态城市，走可持续发展的道路；建立数字城市，实现城市社会信息化；控制城市人口，合理发展城市规模。     

现代谱估计的进展

本文首先详细评述了最大熵谱估计的进展,然后介绍了近年来发展起来的最小交叉熵谱方法、自回归滑动平均谱方法。作为比较,还简述了最大似然谱估计方法。最后讨论了时谱和多谱。     

The fractal geometry of the soil—covered landscape

The soil-covered landscape surface can be idealized from two viewpoints. The intuitive view is of a smooth, absolutely continuous surface with continuous contour lines and measurable in integral dimensions. The alternative view emphasizes the roughness, a surface of little regularity and at the limit of no contours, the appropriate measure being that of fractional Hausdorff dimension. Regularity is a local property and both idealizations need to stop far short of the limit to avoid awkward consequences. The dichotomy of viewpoint can be matched in the theory of Gaussian random fields. These, if they are smooth, are very smooth but if they are irregular they are highly irregular (erratic); there is no middle ground. This Belayev dichotomy is defined and both modes applied to the soil-covered landscape. On the one hand, if the landscape is subject to a general diffusive type degradation or more generally a Davisian downwasting regime then the curvature of the landscape surface is progressively straightened and the distribution of gradient (increments) along a typical traverse will eventually adopt a Gaussian form. Then from the irregular viewpoint the surface is ultimately well represented by a fractional Brownian surface of low Hausdorff dimension (2·0 < dim < 2·3). The Hausdorff dimension is directly related to the entropy of the landscape and as degradation proceeds both quantities decrease in value. On the other hand, if the surface is regarded as smooth and well represented by an absolutely continuous Gaussian field then the mean value of the number of upcrossings of a level or the extent of an excursion set will also be Gaussian. This analysis is restricted to one dimension; the number of times a profile curve crosses or the amount of time it spends above any given level. Predictions from both viewpoints are substantially corroborated in a map analysis of 15 sites on varied terrains in Southern England and the map analysis checked against one based upon digital tape data for one of the sites.     

Calcite formation in microbial mats: modeling and quantification of inhomogeneous distribution patterns by a cellular automaton model and multifractal measures

The evolution of early diagenetic calcite cements in microbial mats of recent supratidal sediments of the southern North Sea is modeled in a two-dimensional microscale approach by a cellular automaton model (CAM). Calcite is traced out in the model by virtual calcium distribution patterns obtained from runs under different assumptions concerning sediment-intrinsic conditions. For justification of the CAM, real calcium distribution patterns, documented by scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDX), are quantitatively compared with the virtual patterns on the basis of multifractal analyses. The formation of high magnesian calcite as a consequence of biogenic anaerobic decomposition of organic matter starts at certain initial calcite domains. In this stage an inhomogeneous and multifractal calcium distribution is characteristic. Nearly complete remineralization of organic matter leads to monofractal behavior of generalized fractal dimensions (D_B(q) ±1.84). The CAM results confirm that calcite formation is a self-determining morphogenetical process and diffusive transport processes of reactants within the mat affect the biogenic calcite formation.     

前震活动特征及其识别的研究（Ⅰ）

分析了近２０年来中国大陆强震（Ｍ≥７．０）和华北地区中强地震前广义前震序列时间和空间分布的多分形特征，计算其广义分维谱Ｄ_ｑ和标度指数谱Ｆ（α），并探讨了它们随时间的变化．结果表明：（１）对广义前震活动，在所研究地区的时、空分布，均呈现多分形结构；（２）大地震发生前半年至一年，地震活动时、空分布的高次分维Ｄ_∞呈下降趋势．这种降维特征，亦在实验室含水大样本岩石破坏前，声发射序列Ｄ_∞的变化中观测到；（３）与中强地震相比，大地震孕育区地震活动的空间高次分维偏低，表明地壳应力分布的高度不均匀性，是板内大地震孕育环境中的本质因素之一．     

断层形变高频波动丛集性前兆和异常判据研究

断层形变短临前兆表现形式是多样的，并作了初步分类，丛集性高频波动是其一种重要现形式，探索了这种前兆信息的提取思路和方法，认为信息丛集度Ｃ是描述这种前兆短临信息，熵值积分平滑值Ｇ是描述中短信息较理想的特征量，震例学表明第二类前兆具有较好的预报效能，对异常判据了初步探索。     

小波变换在遥感图像数据融合中的应用

用小波变换实现了一种新的遥感图像数据融合方法 ,该方法采用梯度算法对不同尺度子带数据进行融合 ,用加权法对基带数据进行融合。给出了 SAR图像与 TM图像的融合结果的定性评价 ,并用熵及平均梯度进行了定量评价     

Indian summer monsoon rainfall (ISMR) forecasting using time series data: A fuzzy-entropy-neuro based expert system

This study presents a model to forecast the Indian summer monsoon rainfall(ISMR)(June-September)based on monthly and seasonal time scales. The ISMR time series data sets are classified into two parts for modeling purposes, viz.,(1) training data set(1871-1960), and(2) testing data set(1961-2014).Statistical analyzes reflect the dynamic nature of the ISMR, which couldn't be predicted efficiently by statistical and mathematical based models. Therefore, this study suggests the usage of three techniques,viz., fuzzy set, entropy and artificial neural network(ANN). Based on these techniques, a novel ISMR time series forecasting model is designed to deal with the dynamic nature of the ISMR. This model is verified and validated with training and testing data sets. Various statistical analyzes and comparison studies demonstrate the effectiveness of the proposed model.