Machine learning for cross-gazetteer matching of natural features

ABSTRACT

Defining and identifying duplicate records in a dataset is a challenging task which grows more complex when the modeled entities themselves are hard to delineate. In the geospatial domain, it may not be clear where a mountain, stream, or valley ends and begins, a problem carried over when such entities are catalogued in gazetteers. In this paper, we take two gazetteers, GeoNames and SwissNames3D, and perform matching – identifying records in each that are about the same entity – across a sample of natural feature records. We first perform rule-based matching, establishing competitive results, then apply machine learning using Random Forests, a method well-suited to the matching task. We report on the performance of a wider array of matching features than has been previously studied, including domain-specific ones such as feature type, land cover class, and elevation. Our results show an increase in performance using machine learning over rules, with a notable performance gain from considering feature types, but negligible gains from other specialized matching features. We argue that future work in this area should strive to be more reproducible and report results on a realistic testing pipeline including candidate selection, feature extraction, and classification.     

“民国清流”名人文化主题数据的组织和可视化方法

历史名人是我国几千年优秀文化的创造者之一,因此传播历史名人文化具有重要的教育意义和文化传承价值。以“民国清流”为对象的历史名人文化是我国文化体系中优秀的组成部分,有关内涵记述多存在于泛文学化的叙述逸闻等文学作品中,缺乏对名人遗存旧址、生平行迹、社交关系等名人文化主题数据的系统化梳理。本文基于异构名人文化数据,构建名人文化数字化框架,并以“民国清流”为例,着重解决名人文化数据的组织与可视化问题。基于名人文化数字化框架,利用文本挖掘提取群体传记中关键信息,动态地展示名人的二维生平行迹、三维故居点位和名人知识图谱,以实现相关信息的智能化查询分析。可视化分析结果揭示了名人群体的中心人物和活动聚集地变化、名人社会关系、名人间交往的亲疏程度及产生交集的原因。因此,本文所提出的方法不仅能让普通民众直观且多维度地了解民国人物特质,还能帮助文学研究者深入梳理和分析人物的生平及社交关系,为传承和宣传名人主题文化开创新模式。     

A deep learning architecture for semantic address matching

ABSTRACT

Address matching is a crucial step in geocoding, which plays an important role in urban planning and management. To date, the unprecedented development of location-based services has generated a large amount of unstructured address data. Traditional address matching methods mainly focus on the literal similarity of address records and are therefore not applicable to the unstructured address data. In this study, we introduce an address matching method based on deep learning to identify the semantic similarity between address records. First, we train the word2vec model to transform the address records into their corresponding vector representations. Next, we apply the enhanced sequential inference model (ESIM), a deep text-matching model, to make local and global inferences to determine if two addresses match. To evaluate the accuracy of the proposed method, we fine-tune the model with real-world address data from the Shenzhen Address Database and compare the outputs with those of several popular address matching methods. The results indicate that the proposed method achieves a higher matching accuracy for unstructured address records, with its precision, recall, and F1 score (i.e., the harmonic mean of precision and recall) reaching 0.97 on the test set.     

多光谱遥感影像中云影区域的检测与修复

提出了一种有效针对多光谱遥感影像的云影检测与阴影区域修复方法。基于同一地区时相相近的两幅影像,充分利用碎云及阴影的光谱特性分别对云影区域进行融合增强,然后采用Otsu算法求解最佳阈值自动检测出云及阴影区域,根据云影的出现会引起两幅影像局部相应区域明显的亮度变化,可排除亮地物和水体的影响,建立归一化的云影密度图,在此基础上,采用线性加权组合与光谱直方图匹配相结合的方法对其加以修复,利用SPOT 4影像进行的实验表明其修复效果完全能够满足应用需要。     

局部单应约束的高精度图像自动配准方法

提出一种基于SIFT特征的抗差图像匹配算法。算法分为两个阶段:①初始匹配,综合利用SIFT特征匹配方法和基于SIFT特征尺度和方位信息的自适应归一化互相关(normalized cross correlation,NCC)方法建立初始相关,并基于几何关系一致性检测剔除误匹配;②匹配传播,在初始相关的基础上,利用自适应NCC和局部单应约束进行匹配传播,迭代产生更多的匹配点并采用几何关系一致性检测剔除可能的误匹配。初始单应采用最小二乘匹配方法估计得到,并采用自适应NCC为其提供良好的初始值。与现有的基于SIFT特征的图像配准方法相比,算法在抗几何变形和配准精度等方面具有优越性。     

土压力传感器在硬土介质中的非线性响应分析

为掌握土压力传感器置于硬土介质中呈现的非线性响应特性,建立了传感器与土介质的相互作用模型,运用有限元分析了满足匹配误差稳定所需的传感器与土介质的模量比条件。进行了传感器的单体标定和级配碎石土介质标定试验,探讨了传感器非线性响应的主要影响因素。计算与试验表明,目前国内主流的双膜土压力传感器在量测硬土介质中的土压力时,由于模量偏小标定曲线非线性显著;土压力传感器单体标定曲线线性度较高且其模量基本稳定,表明土介质的模量变化是引起标定曲线非线性的主要因素;通过将传感器置于与使用环境相近的土介质中进行标定,并采用非线性修正可明显提高硬土介质中土压力量测的准确性。     

断—盖时空匹配及其对油气聚集与分布的控制作用——以南堡凹陷中浅层东营组为例

为研究南堡凹陷中浅层东营组油气分布规律,根据油气输导断裂与盖层时空匹配与油气分布之间的关系,分析油气聚集与分布的控制作用.结果表明:南堡凹陷中浅层断—盖空间匹配关系对油气分布层位的控制作用表现:(1)如果东营组二段泥岩盖层有效厚度大于90～95m,无论馆陶组三段火山岩盖层有效厚度多大,则油气主要分布在东三、四段(简称东二段、馆三段);(2)如果东二段火山岩盖层有效厚度小于90～95m,馆三段火山岩盖层有效厚度大于130～150m,则油气除分布在东三、四段外,还可以分布在东一段和馆四段;(3)如果东三段泥岩盖层有效厚度小于90～95m,馆三段火山岩盖层有效厚度小于130～150m,明下段泥岩盖层有效厚度大于90～95m时,则油气从下至上均有分布.3套区域性盖层封闭能力形成时期早于断裂输导油气的大量时期,可有效封住断裂输导运移来的油气,这是导致3套区域性盖层之下油气相对富集的重要原因.     

黄骅坳陷孔南地区沙河街组井震基准面旋回匹配

提出了井震基准面旋回匹配的概念与方法。该方法通过测井和地震层序地层分析,以高分辨率层序地层学的基准面旋回为约束,利用合成记录建立测井和地震反射之间的匹配关系。采用该方法可获得更可靠的井震匹配关系,并能赋予各主要地震反射轴的层序地层意义,搭建起地震层序地层与高分辨率层序地层之间的桥梁。孔南地区沙河街组30多口井的井震基准面旋回匹配研究结果表明：层序Ⅰ包括4个主要反射轴,A1、A2和A3分别代表了层序Ⅰ内部的3个四级层序初始洪泛面,A4反射轴相当于层序ⅠC3U旋回上升半旋回的初始洪泛面;层序Ⅱ内部主要包括B1和B2 2个正相位连续反射轴,分别代表了层序Ⅱ内部2个基准面旋回的洪泛面;层序Ⅲ内部主要发育了C1和C2 2个明显的正相位较连续的反射轴,其中C1相当于层序Ⅲ的C2U旋回与C3D旋回的分界,C2反射轴对应于层序ⅢC3U旋回的初始洪泛面。各三级层序内部的正相位反射轴通常为四级层序的初始洪泛面或最大洪泛面。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

Abstract

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-wavelet-convolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L₂ norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

三维空间中沙粒旋转对其跃移轨迹的影响

风沙流中沙粒旋转通常具有明显的三维旋转特性。本文通过数值建模考察了三维空间中不同沙粒旋转状态所产生的Magnus力对其跃移运动轨迹特征的影响。在三维坐标系中,X、Y、Z轴分别表示水平、垂直和横向方向,气流沿X方向流动,沙粒起跳时位于XY平面内。结果表明,跃移沙粒仅绕Z轴旋转起跳时,初始起跳角速度的增大会导致在XY平面内的跃移高度和跃移距离减小而降落角增大,但Z方向没有运动发生。跃移沙粒仅绕X轴或Y轴旋转起跳时,绕X轴或Y轴的初始起跳角速度的变化对在XY平面内的跃移轨迹特征量没有显著影响,但沙粒偏离XY平面的偏离距离和偏离角的绝对值随起跳角速度绝对值的增加而增大。因此,沙粒起跳旋转状态对其跃移轨迹有重要的影响。