基于非抽样剪切波变换的遥感图像融合方法

提出了一种基于Mean-shift分割和非抽样剪切波变换(NSST)的多光谱与高分辨率全色图像融合方法。对高分辨率图像进行Mean-shift分割,并利用区域方差将多光谱图像划分为需要进行空间细节增强及需要光谱特征保持的区域;然后利用NSST变换对高分辨率图像和多光谱图像的强度分量进行多尺度分解。分解后的低频子带采用基于四阶相关系数的融合规则进行融合,带通方向子带根据分割所得的区域按区域方差进行融合;最后进行NSST重构得到融合后的强度分量,经IHS逆变换获得高分辨率的多光谱图像。仿真实验表明,与其他4种相关的融合方法相比,该方法能在空间分辨率的提高与光谱信息的保持之间达到良好的平衡,使得融合图像不仅具有较好的光谱保持特性,而且其空间分辨率也能得到有效提高。     

RGB-D SLAM增强现实原木检尺系统构建与测试

将内嵌有ToF相机、面阵相机及IMU的智能手机作为硬件系统,RGB-D SLAM技术实时获取的深度图、位姿等为数据源,构建了RGB-D SLAM增强现实楞堆原木检尺系统。首先设计了基于ToF影像实时估计RGB影像像素深度的方法,实现对待测原木端面几何坐标的初步估计;其次,设计了散形分区去噪算法实现原木端面点云的精确过滤,设计了原木端面曲率估计算法实现对过滤点云可靠性判别;然后,基于PCA等算法实现原木长、短直径方向向量估计,并基于该向量对原木长、短直径进行了估计;最后,以所构建算法为基础在智能手机平台上搭建了增强现实楞堆检尺系统,实现智能手机对原木进行实时检尺、增强现实场景对测量结果实时监督。新型检尺系统通过对6个楞堆334根原木进行了检尺实验,以评估该设备的测量精度。结果显示：原木平均直径估计值的偏差及均方根误差分别为-0.13 cm(-0.35%)及1.05 cm(3.34%);原木径阶化直径估计值的偏差及均方根误差分别为-0.10 cm(-0.22%)及1.33 cm(4.43%);原木材积估计值的偏差及均方根误差分别为-0.007 m³(-0.27%)及0...     

基于DGT技术的土壤铅生物有效性评价研究

采集我国15个省份的耕作土壤进行盆栽试验,通过外源添加不同浓度梯度的Pb并种植小白菜,比较梯度薄膜扩散技术(Diffusive gradients in thin-films,DGT)与传统化学方法(土壤溶液法、EDTA法、HAc法、CaCl_2法和全量法)评价土壤中Pb生物有效性。简单回归分析表明,各评价方法测定的土壤Pb含量与小白菜Pb含量都呈显著相关关系,但DGT技术相关性(R~2=0.97)最高。通过逐步多元线性回归分析,融合土壤pH值、有机碳(OC)含量、阳离子交换量(CEC)、粘粒含量等土壤基本理化性质,建立多元回归模型,结果表明:各传统评价方法融合了pH值、OC含量等土壤性质,R~2较对应的简单回归分析有所提高,都能用于评价土壤Pb的生物有效性,但通过DGT技术所构建的模型方程(R~2=0.97,p0.01)几乎不受土壤性质的影响,且较传统化学方法相关性更高,因此,DGT技术是一种可以用于评价土壤中Pb生物性的较优方法。     

Theoretical Analysis and Testing of Ground Treatment Using an Expansive Method in Very Thick Collapsible Loess

Through technological research of foundation treatments in the collapsible loess areas, we recommend a method of treating foundations in collapsible loess with quicklime piles. We set forth the basic principle of this expansive method. When a very thick foundation in collapsible loess is treated, the computational formula for the volume of expanding material in a quicklime pile is deduced based on cavity expansion theory. This theory is applied to engineering practice. Physical and mechanical properties of the compacted soil are tested. The result shows that the collapsibility of a foundation in loess has been eliminated, its physico mechanical indexes have been improved, and the soil compressibility and the modulus of compressibility also increase remarkably, demonstrating the correctness of the computation theory. The feasibility of the expansive method for very thick collapsible loess areas is further established.     

Damage Evolution and Acoustic Emission Character of Coalrock under Unloading Condition

The damage failure mechanisms of coalrock under unloading condition during deep mining is different from those under traditional loading condition, starting from the unloading condition position to study the dynamic disaster of coalrock has become a new direction in the disaster study. The rock mechanics electrohydraulic servo test system (MTS815) and acoustic emission system (8CHS PCI 2) are used to study the coalrock deformation damage and acoustic emission (AE) characteristics. The results show that the failure of coalrock under unloading condition exhibits strong brittleness and happens in sudden and is mostly of tensile shear failure type. The evolution curve of cumulative ring down count of acoustic emission can better reflect the coalrock unloading damage evolution process, and the whole unloading failure process can be divided into three stages: the stage of damage weakening, damage stably development stage and the stage of accelerated damage development. During the mining process the confining pressure of the coalrock is unloaded, the coalrock rapidly arrives at the third stage of the whole unloading failure process, and the damage is accumulated rapidly and the fracture failure of coalrok occurred suddenly, then follows the coalrock dynamic disaster.     

Improved AHP Assessment Model and Its Practice in Geological Hazard Susceptibility Zoning

Based on the problem during the practice in geological hazard susceptibility zoning, by constructing the three mark (-1,0,1) matrix and introducing optimum transfer matrix, the faintness about weight choice and the consistency check method of judgment matrix for traditional AHP were improved,and the difficult weight quantization problem for each appraise factor of the hiberarchy model had been solved; accordingly, the Improved AHP model had been built. At the last, this method was applied to a concrete zoning practice about geological hazard susceptibility.The application result shows that the zoning practice in Yongchuan region about geological hazard susceptibility is practical and effective.     

Effect of Microorganisms on Some Engineering Properties of Silt

The microbiology was introduced in foundation treatment. Several Carbonate mineralization microorganisms and polysaccharides viscose microorganisms were screened and the microorganisms No.ATCC 6453,3,polysaccharides viscose microorganisms 5 and 6 were used in silt modification. The engineering properties of silt before and after modification were compared by unconfined compressive strength test and indoor seepage test. The microstructures of silt incorporating different microorganisms were analysed by mean of scanning electron microscope and energy dispersive X ray (EDX) analysis. And the modification mechanism of silt has been revealed. These studies indicate that certain engineering properties of silt can be improved by incorporating microorganisms.     

Analysis on Influence of Fault Location and Strength on Deformation and Stress Distribution of Surrounding Rocks of Large Underground Openings

The stability of rock mass project is mainly controlled by the rock mass structure, and faults are the large geological discontinuity plane commonly encountered in rock mass engineering. The stability of surrounding rocks is restricted by mechanical property and location to underground cavern of faults, the detailed studies carried out by analysis of numerical calculation and construction monitoring datum of underground powerhouse of Three Gorges Project show: the distribution of stress and deformation of surrounding rock masses containing a fault are badly deteriorated, the distribution of stress and deformation are obviously different under different natural stress field and position of fault; The influence of friction strength of fault on deformation of surrounding rocks is more obvious when a fault is located near the crown, but the cohesion is more when wall nearby, and the influence is more distinct with side pressure coefficient increases.     

Quantitative Analysis of Influencing Factors for Settlement Generation

In the research of settlement renovation nowadays, because of the lack of a quantitative analysis, it was difficult to get a scientific, reasonable, systemic quantitative conclusion. This paper is presented to build a scientific,systemic and quantitative analysis method through which many influence factors invloved in the research of settlement, such as physical environment, social behavior and relatoins among these factors were quantitatively analyzed to get a system with generative simulation in the whole and detailed quantitative analysis for each individual factor, and to make the communication and judgement of the result easy.      

Discussion on Calculation Pattern of Concrete Filled Steel Tube with Dumbbell shaped Section

Based on the structural feature of dumbbell shaped section of concrete filled steel tube (CFST), a combined spatial beam element is presented. In this structure, two steel tubes, two core concretes, one web and the concrete in web cavity are firstly considered as general spatial beam elements, then they are assembled into a spatial combined beam element according to the plane hypothesis and transformation matrix formed from master and slave nodes. A FORTRAN program for CFST arch with dumbbell shaped section has been developed, and the numerical example shows that the steel tubes and core concretes bear mainly the axial forces with small moments, thus, a modified formula for lattice column method to calculate axial forces of the upper and lower limbs of CFST with dumbbell shaped section is deduced. Comparison of the results from the modified formula with those from an example indicates that the modified formula gives relatively accurate results. 