Implementation of the parallel mean shift-based image segmentation algorithm on a GPU cluster

The mean shift image segmentation algorithm is very computation-intensive. To address the need to deal with a large number of remote sensing (RS) image segmentations in real-world applications, this study has investigated the parallelization of the mean shift algorithm on a single graphics processing unit (GPU) and a task-scheduling method with message passing interface (MPI)+OpenCL programming model on a GPU cluster platform. This paper presents the test results of the parallel mean shift image segmentation algorithm on Shelob, a GPU cluster platform at Louisiana State University, with different datasets and parameters. The experimental results show that the proposed parallel algorithm can achieve good speedups with different configurations and RS data and can provide an effective solution for RS image processing on a GPU cluster.     

湘西北宁乡式铁矿的成因与质量

宁乡式铁矿在湘西北主要分布在三个层位,存在两类矿石结构,这两类矿石结构的铁矿是由不同的成矿方式形成,因而矿石质量也是不同的,具体表现在两类矿石中P、SiO2的含量存在明显差异。通过分析对比,Fe0、Fe22层砾状、豆状类赤铁矿的质量优于鲕状赤铁矿,其中位于二户溪至西界地区的FeO层砾状、豆状赤铁矿矿石质量全区最佳,应为该区的赤铁矿下一步工作的主要方向。     

示波器故障维修

本文介绍了示波器的基本工作原理 ,以ST— 1 0型示波器为例阐述了该仪器常见故障的维修方法     

Review on the Impacts of Public Rail Transport on Urban Land Use Change:A Citespace-based Quantitative Analysis*

The public rail transport system in cities can promote physical urban transition, resulting in land use and land cover change, changing the public daily behaviors and consequently bringing huge economic benefits to its imminent areas. In this study, based on statistical analysis and visualization tools, by using Citespace and Google Earth, we explored approximately 455 papers from Web of Science and 321 papers from CNKI to obtain current research trends in the assessment of the impacts of public rail transport on land use change. The literature classification, organization and comments on such current studies and hot research topics are valuable for future research. Three conclusions were then drawn: First of all, similar topics have been done by both domestic and oversea scholars, but from slightly different perspective and at different scales. Secondly, public rail transport often causes the increase of housing price for both residential and commercial blocks; the influence on population density is more significant in the outskirts than that in downtown areas, but the influence often emerges with an unfixed time lag. Thirdly, RS, GIS and GPS (3S) technologies are promising tools for the research of the impacts of public rail transport on land use change in the era of "big data". Based on the conclusions, four suggestions were proposed: Firstly, future research in this field will be more comprehensive and humanistic studies. Secondly, overseas development models could not be fully applied in China, and thus corresponding improvement with China's situation are required. Thirdly, theoretically speaking, bicycle sharing can expand the service range of public rail transport. Fourthly, reasonable allocation of buffers is important for obtaining fine statistical area of land change affected by public rail transport.     

非饱和土壤水分函数解析与Richards方程入渗新解

从土壤微观统计学角度出发，用各向均一无结构土壤“切片”孔径级配函数构建的统计毛管束模型和土壤水分分布依赖的力学原理，论证了理查兹方程中导水率、基质势、扩散率等水分函数和入渗率随充水度，土壤基质而变的机理、规律以及两者之间的内在联系，给出了相应的计算公式和可操作的参数确定方法。把迄今水分函数研究的纯经验相关现状提高到理论分析水平，使建立理论公式成为现实。     

试论县(市)级地矿GIS的构成

通过对地理信息系统(GIS)在我国的发展及在地矿方面应用的简单回顾,对县(市)级地矿地理信息系统特点的分析,提出了该系统的构成框架。认为:县(市)级地矿GIS应由基础信息子系统、管理子系统和分析评估子系统三个子系统组成,管理子系统是地矿工作人员直接运用的管理工具,分析评估子系统是面对各种复杂地矿问题的决策帮手,而基础信息子系统则是管理子系统和分析评估子系统的数据来源。三个子系统各自具有独立的功能,在系统运行中又紧密结合在一起。由以上三个子系统组成的GIS系统,具有组织紧密、层次分明、实用性强等特点。     

黔东北沿河县奥陶系湄潭组碎屑锆石特征、物源——构造意义及其成矿年代学启示

黔东北沿河县位于中扬子地区,分布有众多低温热液矿床,构造上位于加里东期前陆盆地的隆后带,是研究盆地物源-构造响应的良好场所,然而在中扬子的大部分地区,奥陶纪地层序列多以碳酸盐岩为主夹泥质岩,因而从岩性上制约了碎屑锆石年代学等定量分析手段的开展。近来,笔者注意到沿河县及周边地区下—中奥陶统湄潭组(O1-2m)为泥岩、灰岩夹(钙质)砂岩,采样分析结果表明,湄潭组碎屑锆石年龄大于1.0 Ga的锆石仅8颗(占12%)且未形成峰值,最年轻一组谐和年龄的加权平均值((457.8±8.1)Ma)与该组沉积上限十分接近,反映湄潭组碎屑主要来自新隆升的物源区,且具有相对较高的沉积速率。根据年龄的分布和特征峰值,可分为5组:～461 Ma(Ⅰ)、～580Ma和～606 Ma(Ⅱ)、～722 Ma(Ⅲ)、～865 Ma(Ⅳ1)和～936 Ma(Ⅳ2),其中Eu正异常的锆石集中分布于第Ⅰ组(占62%),而在第Ⅱ组和第Ⅳ2组中缺失,结合稀土元素等的分析,认为其物源主要分为3部分,第Ⅰ组、第Ⅱ组和第Ⅳ2组、第Ⅲ和Ⅳ1组,分别主要来自3个不同的物源区,分别对应黔中隆起、扬子西缘康滇古陆(另有少量来自扬子东南缘—华夏地区)、武陵—雪峰隆起。此外,第Ⅰ组年龄450～511 Ma范围内发育了高达73%的热液锆石,与区域低温热液成矿时间对应,认为其形成是物源区流体的活跃导致的,可能与奥陶纪区域构造体制从伸展到挤压的转换有关,暗示此时加里东运动已经开始波及中扬子沿河地区,但主要表现为热液活动,并没有发生大规模岩浆作用。     

湖北长阳矿业发展战略

根据长阳土家族自治县矿产资源的现状和特点,从边远山区较为落后的经济和本区及周边现有的工业布局出发,分析目前矿业开发存在的问题。为保障尽快提升长阳地区经济水平,切实有效保护环境,必须进一步改进矿产资源利用方式,实行科学的矿业发展战略。     

计算机在采矿登记工作中的应用——DBASE编程和MIS软件的比较

应用管理软件在行政管理工作中的作用及投入的重要性。以采矿登记管理为例,通过对ＤＢＡＳＥ数据库编程和ＭＩＳ管理软件各自特点的分析比较,结论是：应用ＭＩＳ管理软件可进行方便、快速的检索、查询和分析,无须手工编程的繁琐。     

无人机输电线路测量点云自动分类与快速巡检

本文基于无人机激光点云数据进行输电线路特征对象的分类提取与快速巡检,首先对多无人机平台通过空中测量的手段获取得到的数据进行了对比分析,然后针对固定翼无人机激光点云数据进行杆塔、导线、植被和地面的自动分类与提取,并进行导线修复,最后得到当前工况安全距离检测报告.结果 表明,固定翼无人机激光雷达系统一方面可以进行输电线路快...