EDGE DETECTION METHOD OF REMOTE SENSING IMAGES BASED ON MATHEMATICAL MORPHOLOGY OF MULTI-STRUCTURE ELEMENTS

This paper puts forward an effective, specific algorithm for edge detection. Based on multi-structure elements of gray mathematics morphology, in the light of difference between noise and edge shape of RS images, the paper establishes multi-structure elements to detect edge by utilizing the grey form transformation principle. Compared with some classical edge detection operators, such as Sobel Edge Detection Operator, LOG Edge Detection Operator, and Canny Edge Detection Operator, the experiment indicates that this new algorithm possesses very good edge detection ability, which can detect edges more effectively, but its noise-resisting ability is relatively low. Because of the bigger noise of remote sensing image, the authors probe into putting forward other edge detection method based on combination of wavelet directivity checkout technology and small-scale Mathematical Morphology finally. So, position at the edge can be accurately located, the noise can be inhibited to a certain extent and the effect of edge detection is obvious.     

基于3维可视化环境的地质体空间形态分析

针对3维矿床地质体既具有复杂的几何形态特征,又具有连续的矿化分布与控矿作用分布等空间分布场特征,结合3维地质建模软件Datamine的可视化环境,基于线框模型研究了地质体实体建模与3维可视化过程;在此基础上将实体模型离散化输出为体素模型,提出采用趋势面分析方法和基于数学形态学的分析方法进行地质体空间形态分析,比较和研究了这两种方法提取地质体空间趋势形态和形态起伏特征的过程。实例研究和论证了基于数学形态学滤波的地质体空间形态因素分析和提取方法处理某方向上存在有超覆现象的可行性。     

数学形态学在二值数字图像断续线形目标恢复上的应用

特征提取中,由于地物特征的差异及其它因素的影响,提取的目标大多是非连续的,这将导致提取的目标与实际情况不符合,若不进行恢复,势必影响对目标性质的认识和应用。本文基于数学形态学方法,首先对二值图像中非连续的线性目标进行了分析和处理,然后对结构元素的选取和分解进行了阐述。最后的实验结果表明,该方法效果较好。     

Morphological evolution of the Dee Estuary, Eastern Irish Sea, UK: A tidal asymmetry approach

Asymmetry in the tide (unequal ebb and flood duration) is a dominant factor in causing residual sediment transport and morphological changes in estuaries. The evolution of estuarine morphology is a process of dynamic equilibrium in the short-term, while these features are ephemeral in the long-term. In this study we investigate the spatial distribution of tidal distortion and asymmetry in the Dee estuary, UK, by 3-dimensional numerical modelling methods. High resolution LIDAR surveys are used to underpin and explain our numerical modelling results in terms of basin hypsometry and areas of recent erosion and deposition. Harmonic analysis of the numerical modelling results showed that the shallower intertidal areas (sand and mud banks) were the most tidally asymmetric, showing flood dominance. The main navigation channels showed some ebb dominance but the tides here were relatively undistorted. This overall flood dominance is likely to induce net sediment import to the Dee, which explains known historical morphological changes (large scale accretion over the last two centuries) and also recent morphological changes as seen from the LIDAR surveys (which show predominantly net accretion between 2003 and 2006). Hypsometrical analysis suggests the Dee may be approaching equilibrium, and that the flood dominance and sedimentation rate may therefore decrease in the future. In an infilling estuary, an increase in the area and elevation of tidal flats can eventually shift an estuary towards ebb dominance, as shown by previous research and by ‘idealised estuary’ modelling results presented in this study. The large tidal amplitude to hydraulic depth ratio of the Dee, however, suggests that the tidal flats would have to be very extensive indeed for this to occur.     

Advances in the Effects of Wind on Plants

Wind is a important factor. It can strongly affect development, growth and reproduction of terrestrial plants. The plant in wind environment can adapt to wind by special mechanism to decrease damage. This paper reviews the effects of wind on plant in phenotype, anatomy and root archetecture. Some plant species show a resistance strategy, but other species show an avoidance strategy. After the analysis of the restriction of current research in this area, the authors suggest that studies in the area should be extended to taking the whole plant as an integrated system rather than focusing on specific tissue level. Furthermore to understand the general mechanism across species, it is required to study different species from different environmental conditions. Advances in bioinformatics, molecular and physiological research will facilitate cross disciplinary studies to understand the complicated responses of plants to wind.     

The role of vortex shedding in the scour of pools

Flume experiments were conducted in a 6-m flume to determine the role of turbulence in the scour of pools. Paired results from constricted-flow experiments with and without a wake zone formed behind obstructions to flow show that pools are deeper and shorter when vertical free-shear layers are present. Although non-streamlined obstructions initially present more resistance to flow, channel-bed scour develops a pool morphology that lowers mechanical energy losses to levels below those in pools with streamlined obstructions. Scour primarily enlarges the cross-sectional area in the constricted section. Feedback between pool geometry and localized turbulence production play a secondary role in total scour but still exert a major influence on final energy slopes. The experiment shows that pools with wake zones evolve to reduce longitudinal energy expenditure with an associated reduction in total turbulence production associated with the obstruction.     

Platyceratid gastropod infestations of Neoplatycrinus Wanner (Crinoidea) from the Permian of West Timor: speculations on thecal modifications

Distinctive trace fossils, indicating the infestation of the monobathrid camerate crinoid Neoplatycrinus Wanner by coprophagous platyceratid gastropods, are recognised for the first time from the Permian of West Timor. Platyceratid shells from West Timor have previously been reported preserved on or about the crinoid tegmen, that is, apically; in contrast, the trace fossils described herein occur in the CD interray (=posteriorly), mainly on the radials. There are two patterns of infestation in the CD interray. Circular grooves in this position, situated below the periproct, are referred to Lacrimichnus isp. Thecal modifications include the CD interray sloping towards the base, and incomplete curved ridges developed outside the circular groove and confined to the radials. A different morphology is shown by other specimens that have a broad, flattened CD interray, curving down to and extending onto the basals; this interray also slopes towards the base. These unusual CD interray modifications are interpreted as a product of snail/crinoid associations. We speculate that the major modifications to the theca may have permitted the platyceratid shell to mimic an uninfested CD interray and thus maintain the hydrodynamic integrity of the crown. This would have been to the advantage of both gastropod and crinoid. The camerates did not survive the P/Tr extinction; their demise ended an association that had persisted over 200 million years, although the platyceratids persisted into the Mesozoic.     

Creating Mountains out of Mole Hills: Automatic Identification of Hills and Ranges Using Morphometric Analysis

This article examines the relationship between scale of observation and landform features and their representation in map form. The research is premised on the idea that large scale features are defined by the smaller features that comprise them (that mountain ranges are a collection of clustered yet individually identifiable mountains or hills). In preference to subjective selection of the higher order features, we propose a methodology for automatically discerning mountain ranges as well as the smaller hills that constitute them. A mountainous region can be defined by its prominence (relative height among surrounding features) and various morphological characteristics including the variability in morphology. The algorithm presented here uses derivatives of elevation and the density of morphological properties in order to automatically identify individual hills or mountains and ranges together with their extents. Being able to create generalised views of landscape morphology is considered to be part of the model generalisation process and is an essential prerequisite to spatial query and to the cartographic portrayal of these features at a range of scales (levels of detail). For the purposes of evaluation the algorithm was applied to the hills around Edinburgh city and the hills and ranges around Fort William, Scotland. The research reflects on the challenge of defining the subjective nature of what is a ‘hill’ or a ‘mountain’, but reminds us that a map seeks to capture the essence and characteristic form of the landscape – something that is necessarily fuzzy and scale dependent.     

不同降维策略下的高光谱影像多特征分类

由于物体表面的空间分布通常是富有规律且局部连续的,在高光谱影像分类中应充分利用其光谱和空间信息.本文在对高光谱影像立方体进行降维处理的基础上,提出了一种联合空域和谱域信息的高光谱影像高效分类方法.首先,分别选用主成分分析(Principal Component Analysis,PCA)和正交投影波段选择(Orthog...