利用后方交会测量水底点高程的新方法研究     

彭鑫  王海  欧阳亚 《测绘与空间地理信息》2019,42(4):191-193

在没有测深仪和船只的情况下,本文探索出"测绳测距,后方交会"的新方法,利用测绳测量水底点到岸边两个已知点的距离,根据后方交会原理计算水底点的平面位置和高程,该方法外业操作方便,内业计算简单,为水深测量提供了新的思路。  相似文献   

城市派出所空间位置优化及警力分配     

孙立  王中辉  孙立坚  徐智邦  朱钰  王镕 《地球信息科学学报》2019,21(3):346-358

提高公安派出所的治安防控能力是解决我国城市治安问题的有效途径之一。本文从公安派出所空间位置优化和警力分配两个角度出发,针对当前公安派出所空间位置布局较为随意及警力资源紧缺的现状,以及多目标优化的需求,结合新兴空间大数据和犯罪数据,进行派出所多目标空间优化研究,包括派出所空间布局的数学期望、量化指标以及多目标空间优化模型,并在相关理论模型的基础上利用犯罪热点和房屋建筑分布的空间异质性开展派出所警力（治安和户籍分类）的空间分配研究。以兰州市中心城区为分析区域开展公安派出所空间位置优化和警力分配实验,结果表明：① 在不增加派出所数量、最大维持原有空间布局的前提下,本文提出的方法能有效降低派出所服务区重叠度（17.2%）和平均响应时间（6.67 s）,提高面积覆盖度（12.01%）和需求点覆盖度（7.25%）,并有效提高研究区内各区域应急响应时间的公平性（基尼系数由0.382降低到0.268）;② 数据分析发现,城市犯罪热点以及房屋建筑空间分布均存在空间分异现象。理解并量化分析空间分异特征,有助于优化派出所治安和户籍警力的配置。  相似文献   

Underwater Object Recognition Based on Deep Encoding-Decoding Network     

WANG Xinhua  OUYANG Jihong  LI Dayu  ZHANG Guang 《中国海洋大学学报(英文版)》2019,(2):376-382

Ocean underwater exploration is a part of oceanography that investigates the physical and biological conditions for scientific and commercial purposes. And video technology plays an important role and is extensively applied for underwater environment observation. Different from the conventional methods, video technology explores the underwater ecosystem continuously and non-invasively. However, due to the scattering and attenuation of light transport in the water, complex noise distribution and lowlight condition cause challenges for underwater video applications including object detection and recognition. In this paper, we propose a new deep encoding-decoding convolutional architecture for underwater object recognition. It uses the deep encoding-decoding network for extracting the discriminative features from the noisy low-light underwater images. To create the deconvolutional layers for classification, we apply the deconvolution kernel with a matched feature map, instead of full connection, to solve the problem of dimension disaster and low accuracy. Moreover, we introduce data augmentation and transfer learning technologies to solve the problem of data starvation. For experiments, we investigated the public datasets with our proposed method and the state-of-the-art methods. The results show that our work achieves significant accuracy. This work provides new underwater technologies applied for ocean exploration.  相似文献   

Android水平位移即时监测终端软件的实现     

欧阳晨皓  黄永帅  刘冠兰  史俊波 《测绘通报》2019,(3):86-90

水平位移形变监测是轨道交通工程中十分重要的一环。随着移动互联技术和智能终端的发展及其在水平位移形变监测中的应用,监测的即时性及数据安全问题显得越来越重要。本文实现了一套基于Android设备的水平位移即时监测终端软件,通过Android设备的蓝牙、网络通信功能,将监测设备、Android设备、监测信息服务平台联系在一起,保证了监测的即时性;内嵌数据加密算法,保证了监测数据安全性。实际轨道交通工程中的应用表明:本文开发的终端软件实现了监测数据的实时采集和处理,提升了监测作业效率;实现了监测数据的加密,完善了工程安全机制。  相似文献   

VC、VB与FORTRAN的混合编程技术及其实现   总被引：4，自引：0，他引：4  

欧阳永忠  王瑞  陆秀平  申家双  王克平  刘传勇  侯世喜 《海洋测绘》2004,24(1):54-59

在探讨高级编程语言之间混合编程技术的基础上,通过实例在Visual C 6．0、Visual Basic 6．0和Fortran Power Station4．0开发平台上演示了VC、VB和FORTRAN之间动态连接库(DLL)模式混合编程的实际应用,为使用不同开发平台的程序员和涉及知识产权保护的单位之间协作开发高质量的软件提供了技术途径。  相似文献   

地震频段弹性模量测试系统改进与升级     

李智  欧阳芳  肖增佳  龙腾  贺艳晓  赵建国 《地球物理学报》2022,65(5):1769-1784

获取地震频段弹性模量对于地震数据定量解释、研究地震波传播特征及油气勘探开发具有重要意义.前期建立的测试系统基于应力应变法可以获得地震频段内岩心的杨氏模量、泊松比和衰减.该系统仅适用于φ38 mm岩心,而测量物性参数(孔隙度、渗透率等)、测量超声纵横波速度时一般使用φ25 mm岩心.为将 φ25 mm岩心应用于地震频段弹...  相似文献   

强夯地震效应浅析   总被引：3，自引：0，他引：3  

欧阳立胜  王迪洁 《华南地震》2004,24(3):96-100

为了评估强夯地震效应对周边建筑物的影响,从时域、频域等角度分析强夯地震效应的衰减规律,给出了强夯地震动加速度。与距离R的衰减关系。对强夯地震信号做频谱分析表明,强夯地震波振动主频一般都小于10Hz,其地震效应与天然地震较为接近,因此,选用《中国地震烈度表》(GB／T17742—1999)作为衡量振动对周围建筑物影响的标准,并由此确定一定能级的强夯振动对周围建筑物的影响范围。  相似文献   

管道数据集的存储与管理     

韩小明  周利剑  冯庆善  王颖 《地理空间信息》2010,8(6):86-88

采用通用的管道数据模型ArcGIS Pipeline Data Model(APDM)和ESRI GeoDatabase技术,从管道数据集存储步骤、历史数据归档、数据相关性管理三方面,详细阐述了对管道数据集进行有效管理的技术方法。  相似文献   

Monitoring near-surface soil freeze–thaw cycles in northern China and Mongolia from 1998 to 2007     

Lijian Han  Atsushi TsunekawaAuthor VitaeMitsuru TsuboAuthor Vitae 《International Journal of Applied Earth Observation and Geoinformation》2010

Remote sensing based near-surface soil freeze–thaw cycles detection in middle latitude especially where near-surface changing seriously still rare. In this research, soil temperature and 7-day maximum/minimum combined passive microwave brightness temperature were employed to apply a soil freeze–thaw algorithm in northern China and Mongolia. We proposed a random sampling technique to determine brightness temperature thresholds for 37 GHz vertically polarized radiation: 258.2 and 260.1 K for the morning and evening satellite passes, respectively, and determined the onset, offset, and duration of the phases of the near-surface soil freeze–thaw cycle. During the 10 years from 1998 to 2007, the onset and offset of soil frozen/thawed in spring and autumn progressed from south to north and northwest, and from low elevation to high elevation. The durations of the freeze–thaw transitions in spring, autumn and whole year were longest in the Loess Plateau, Ordos Plateau, and Songnen Plain, where they were 1–3 weeks longer than in other regions. The total annual durations of soil frozen/thawed increased/decreased progressively from the south to both the northwest and northeast. Over the 10 years, changes to both the timing and duration of phases of the freeze–thaw cycle were greater in spring than in autumn. Most of the changes were less than 2 weeks, but there were changes of up to 3–4 weeks on the Northeast Plain, Loess Plateau, and at Mt. Yinshan. Our research has contributed to understanding near-surface earth systems and suggests that changes in earth surface may cause extreme environmental events such as the dust emission in semi-arid and arid regions of East Asia.  相似文献   

基于高性能有限单元的单桩稳定性分析法     

万建宏  郑翔之  欧阳苇航  刘思威  黎学优 《岩土力学》2020,41(8):2805-2813

现行的桩基设计方法主要基于线弹性理论及采用半经验假定,难以准确地检验长桩在土体非线性条件下的稳定性。基于非线性有限单元分析理论,提出了高性能桩单元分析法用于非线性分析,可直接检验单桩稳定性且无需假定桩的计算长度系数。在桩单元推导过程中,通过整合在单元内部的连续弹簧以考虑土-结构相互作用（SSI）,能够大幅提升计算效率。使用牛顿-拉夫逊迭代法进行迭代运算,利用推导的相应单元切线刚度矩阵预测位移,并通过割线关系减少每一步迭代中产生的误差,在桩的大变形条件下采用更新拉格朗日法确定平衡条件。算例验证表明,桩单元模型在考虑土体非线性条件下,能高效、可靠地对单桩进行分析和设计。  相似文献