基于分水岭与多尺度相结合的影像分割方法

分水岭分割是一种应用较广泛的影像分割方法,它能自动生成单像素宽度的封闭轮廓,但需要把影像分割成过多小区域,从而导致影像分割耗时且工作量大。本文就此提出一种分水岭和多尺度相结合的高分辨率影像分割方法。该方法首先运用分水岭方法对融合了亮度梯度和纹理梯度的综合梯度进行计算,然后将同质性度量值最小的区域对合并,最后结合改进区域邻接图进行区域合并。实验结果与基于分水岭和区域合并的影像分割算法得到的结果进行比较,证明该方法不仅能充分利用高分辨率遥感影像中地物的光谱、形状、纹理等特征,而且减少了计算时间。

基于改进标记控制分水岭方法的树冠轮廓提取

针对密林区和疏林区的林木遥感图像的单木树冠轮廓提取,首先引入改进的同态滤波对图像进行预处理,然后采用标记控制分水岭分割方法进行图像轮廓提取。引入的改进同态滤波能够去除混合噪声且不会破坏边缘信息,因此预处理后的图像边缘信息较为完整,从而保证了良好的轮廓提取效果。最后,结合人工识别结果,将改进的标记控制分水岭分割方法与未改进方法的提取结果进行比较,发现改进方法对疏林区的树冠轮廓提取效果明显好转,提取精度较高且易编程实现。

图像序列处理中的形态分割方法

将数学形态学应用到序列图像分析中 ,提出了一种基于图像序列的 3- D形态分割算法 ,对图像序列简化后进行边缘增强 ,用改进的 3- D分水岭方法提取分割信息 .基于分割信息对几种常用图像序列的处理算子和处理方法进行了研究和改进 .实验结果表明 ,该方法能对序列图像有效地进行时空分割 ,利用分割信息可显著提高各种图像序列处理的性能 ,而且具有算法简单、效率高的特点 .

改进分水岭和区域增长的激光医学图像分割

为了提高激光医学图像的分割精度,针对传统分水岭方法存在的不足,提出一种改进分水岭和区域增长的激光医学图像分割方法。首先对采激光医学图像进行双边滤波,消除噪声,防止边缘细节信息丢失,然后分水岭方法对激光医学图像进行分割,并针对传统分水岭方法不足进行相应的改进,最后采用区域增长方法对图像分割的结果进行处理,使分割目标更加完整,并通过仿真实验分析其有效性。结果表明,相对于传统分水岭方法以及其它分割方法,本文方法获得更高了的激光医学图像分割精度,对噪声鲁棒性更强,可以为临床医学诊断提供重要依据。

一种精确的运动目标外轮廓提取方法

视频监控系统中的运动目标外轮廓是对运动目标语义分析的重要信息源。针对经过简单的形态学处理运动目标区域而提取的外轮廓方法中的一些缺陷,提出一种更精确的方法。首先通过前景检测得到粗略确定的运动目标区域,然后通过分水岭方法进行外轮廓区域粗略定位,最后通过阴影去除及目标重构进行外轮廓区域精确定位,从而提取精确的外轮廓。利用外轮廓的准确率、查全率、综合性能指标,实验结果表明,能够得到精确的外轮廓。

基于语义分割的炼铁球团粒径在线检测算法研究

铁矿成团过程中,对球团粒径有严格要求。为了能实时检测球团粒径,本文通过对造球机的动态区域图像进行分析,提出了前景提取加粘连分割的球团分割算法。该算法针对图像球团背景矿粉干扰问题,在Unet基础上融入可分离卷积结构,设计了轻量化的DSC-Unet前景分割网络,保证了前景分割的鲁棒性;同时针对球团相互重叠问题,使用了一种基于距离变换的分水岭分割方法,实现了前景粘连的分割,进而通过圆形拟合,获得球团直径。试验结果表明,所涉算法分割准确率达到97%,优于现有其他算法,达到了检测要求。

江西抚河流域水量分配方案研究

探讨有利于江西抚河流域水资源可持续利用的水量分配方法,从尊重用水现状原则、公平原则、公平与效率兼顾的原则出发,采用用水定额预测法、综合权重法、层次分配决策法对水量分配进行了多角度分析,初步形成了综合性的分水方案,最后运用方案模拟模型确定了技术推荐方案。

复杂金属晶界的准确提取技术

在晶粒度定量评定时,对复杂晶界处理效果差。为解决这一问题,对复杂金属晶界的准确提取技术进行了研究。对金属晶粒度评级的步骤进行分析可知,晶界的准确重建是得到准确定量结果的关键,为此需要解决晶界间断不连续的问题。设计了两种晶界断点连接方法,对比表明,形态学分水岭阈值分割方法的效果更好,但需要解决过度分割和未分割的问题。据此,提出了复杂晶界的准确提取方法,即对区域极小值点进行有效编辑,或在应用watershed变换前在灰度图像上将断点进行连接。

在不同彩色空间的分割效果的比较研究

本文是用实验的方法,利用分水岭算法对一幅图像在不同的彩色空间RGB、HSI和YIQ进行分割,然后对其分割效果进行定量比较。结果表明,对RGB空间要比对HSI和YIQ空间的分割效果好,而对YIQ空间比对HSI空间的分割效果要好,但经方差分析,他们之间没有显著差异。

Separation of Oil from Wastewater by Column Flotation

A new type of device,a dissolved-air flotation column,was developed for separation of oily wastewater. The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and column flotation. The dissolved air release occurred within the column separation system. As a potential application the column was investigated for its performance in separating emulsified oil droplets in oily wastewater. A high separation efficiency was obtained in a series of tests. The aeration performance of the bubble generator used in the dissolved-air flotation column was also studied in particular.

A level set based segmentation approach for point-sampled surfaces

Segmenting a complex 3D surface model into some visually meaningful sub-parts is one of the fundamental problems in digital geometry processing. In this paper, a novel segmentation approach of point-sampled surfaces is proposed, which is based on the level set evolution scheme. To segment the model so as to align the patch boundaries with high curvature zones, the driven speed function for the zero level set inside narrow band is defined by the extended curvature field, which approaches zero speed as the propagating front approaches high curvature zone. The effectiveness of the proposed approach is demonstrated by our ex- perimental results. Furthermore, two applications of model segmentation are illustrated, such as piecewise parameterization and local editing for point-sampled geometry.

Innovative trend analysis of annual and seasonal precipitation in Ningxia,China

Based on daily rainfall data from 26 station records,spatial and temporal variations in annual and seasonal precipitation of different rainfall intensities from 1961 to 2018 in Ningxia,China are investigated using the innovative trend analysis(ITA)method.The results show that annual precipitation increases on the northern plain but decreases in the southern mountainous area.The increase in regional annual precipitation is mainly due to an increase in weak precipitation,while the decrease in regional annual rainfall is a result of a reduction in heavy precipitation.Lowintensity precipitation shows an upward trend,while high-intensity precipitation shows a downward trend.The variation trend of extreme precipitation is more obvious.The contributions of different types of extreme precipitation vary by season.During spring,the increase in regional rainfall is mainly caused by the increase in heavy precipitation,while the decrease in regional precipitation is mainly caused by the decrease in weak precipitation.During summer and autumn,the increase in regional precipitation is caused by the increase in light precipitation,while the reduction in regional rainfall is caused by the decrease in heavy precipitation.This study provides support for water resources planning and addressing droughts and floods.

Analysis of Ethanol Dehydration Products by Gas Chromatography

An accurate reliable analysis method for dehydration of ethanol to ethylene was established using chromatographic separation technique and the principle of carbon balance, and the activivity of HZSM-5 molecular seive was evaluated. The results showed that at an ethanol mass concentration of 50%, a mass space velocity of 2.0/h and a temperature of 280 ℃, the activity of catalyst was ideal, and the conversion rate of ethanol and the selectivity of ethylene were up to 99.60% and98.10%, respectively. The selectively of ethylene decreased notably with further increase of reaction temperature.

A Scheme of Fragile Watermarking Based on SVD and 2D Chaotic Mapping

This paper proposed a novel fragile watermarking scheme based on singular value decomposition (SVD) and 2D chaotic mapping. It obtains chaotic initial values from the image blocks singular value decomposition and the user’s key, then uses the chaotic mapping to get the chaotic sequence and inserts the sequence into the LSBs of the image blocks to get the watermarked image blocks. The paper reconstructed the watermarked image from all the embedded blocks. The analysis and experimental results show that the scheme is pretty fragile to tampering, and it can localize the tampering position accurately, reach 3×3 blocks.

Computation of one—dimensional consolidation of double layered ground using differential quadrature method

The authors give the solution to the problem of one-dimensional conso l idation of double-layered ground with the use of the differential quadrature me t hod. Case studies showed that the computational results for pore-water pressure in soil layer agreed with those of analytical solution; and that in the computat ional results for the interface of soil layer also agreed with those of the anal ytical solution except for the small discrepancies during shortly after the star t of computation. The advantages of the solution presented in this paper are tha t compared with the analytical solution, it avoids the cumbersome work in solvin g the transcendental equation for eigenvalues, and in the case of the Laplace transform s olution, it can resolve the precision problem in the numerical solution of long time inverse Laplace transform. Because of the matrix form of the solution in th is paper, it is convenient for formulating computational program for engineering practice. The formulas for calculating double-layered ground consolidation may be easily extended to the case of multi-layered soils.

Optimal Dispatching of Large-scale Water Supply System

This paper deals with the use of optimal control techniques in large-scale water distribution networks. According to the network characteristics and actual state of the water supply system in China, the implicit model, which may be solved by utilizing the hierarchical optimization method, is established. In special, based on the analyses of the water supply system containing variable-speed pumps, a software tool has been developed successfully. The application of this model to the city of Shenyang (China) is compared to experiential strategy. The results of this study show that the developed model is a very promising optimization method to control the large-scale water supply systems.

Flotation bubble image segmentation based on seed region boundary growing

Segmenting blurred and conglutinated bubbles in a flotation image is done using a new segmentation method based on Seed Region and Boundary Growing（SRBG）.Bright pixels located on bubble tops were extracted as the seed regions.Seed boundaries are divided into four curves：left-top,right-top,right-bottom, and left-bottom.Bubbles are segmented from the seed boundary by moving these curves to the bubble boundaries along the corresponding directions.The SRBG method can remove noisy areas and it avoids over- and under-segmentation problems.Each bubble is segmented separately rather than segmenting the entire flotation image.The segmentation results from the SRBG method are more accurate than those from the Watershed algorithm.

Urban Water Resource Utilization Efficiency in China

The efficient use of water resources directly affects environmental, social, and economic development; therefore, it has a significant impact on urban populations. A slacks-based measure for data envelopment analysis （SBM-DEA） has been widely used in energy efficiency and environmental efficiency analyses in recent years. Based on this model, data from 316 cities were examined and a category method was employed involving three different sorting techniques to empirically evaluate the efficiency of urban water re- source utilization in China between 2000 and 2012. The overall efficiency （OE） of urban water resource utilization in China was initially low, but has improved over the past decade. The scale efficiency （SE） was higher than the pure technological efficiency （PTE）; PTE is a major determining factor of OE, and has had an increasingly significant effect. The efficiency of water resource utilization varied ac- cording to the region, urban scale, and economic function. The OE score for the eastern China was higher than for the rest of the region, and the OE score for the western China was higher than for the central China. The OE score for urban water resource utilization has improved with urban expansion, except in the case of small cities. The SE showed an inverted U-shaped＇ trend with increasing urban expansion. The OE of urban water utilization in comprehensive functional cities was greater than in economic specialization cities, and was greater in heavy industry specialization cities than in other specialization cities. This study contributes to the field of urban water resource management by examining variations in efficiency with urban ~ezle

Nitrate Leaching in an Irrigated Wheat-Maize Rotation Field in the North China Plain

Soil water deep drainage and nitrate (NO-3) leaching losses below the root zone were investigated in a 1 ha wheat-maize rotation field under traditional agricultural management that local farmers generally follow in the North China Plain, using the soil water balance method and NO3-N concentration in suction samples. Water drainage, and NO3-N distribution and leaching losses exhibited pronounced spatial and temporal variability. Soil water deep drainage and NO3-N leaching loss mostly occurred during the sum…

Application of Liquid Solid Semi-moving Bed to Fractionation of Cesium Ion in Wastewater

A liquid solid semi-moving bed with non-mechanical particle transport system is proposed and used for fractionation of cesium ion in wastewater. The particle transport system, which consists of a suction chamber, a mixing chamber, a nozzle and a riser tube, is designed to be controlled completely by hydraulic force. Experiments show that continuous feeding and discharging of resin can be realized by the transport system. The removal of cesium ion from wastewater is realized, The concentration of cesium ion in effluent liquid remains below 0,1g·L^-1 （the initial concentration is 5,3g·L^-1） during the 73 hours＇ experiment. The average exchange capacity of resin discharged from the bed is 0.57mmol,（g dry resin）^-1, which is close to the saturated capacity of 0.65mmol·g^-1. And it is also proved that the non-homogeneity of particle vertical velocity along the radial direction can seriously influence the ion-exchange process.