可控源音频大地电磁测深在地热资源中的应用

可控源音频大地电磁测深(CSAMT)是在大地电磁测深法(MT)的基础上发展起来的一种人工源电磁测深法。国内一些单位采用可控源音频大地电磁测深法在探寻地热及地下水资源等方面做了大量工作,取得了良好的实际应用效果。在某温泉旅游区进行了物探方法,通过卡尼亚视电阻率共轭梯度反演断面异常为例进行分析解释,探讨了可控源音频大地电磁测深法在地热地球物理勘查中的应用效果。     

二维大地电磁反演方法对比研究

摘要：通过对几种理论模型的反演结果对比,分析二维大地电磁中常用的OCCAM和RRI反演方法的优缺点。在进行实际资料处理的过程中,根据不同的目标任务选取合适的反演方法进行资料处理,提高资料的解释精度和研究区的地球物理、地质认识。     

音频大地电磁(EH4)在芦家地铁矿区勘查中的应用

目前查找磁铁矿最有效的方法是地面高精度磁法测量。本次工作是在高精磁测基础上,采用音频大地电磁EH4测量方法,对深部磁异常实施EH4剖面测量,依据地电分布特征,对深部矿体基本形态、规模以及构造特征等进一步解译。电、磁综合方法的有效配合,为研究该区的构造特征、矿(化)体赋存部位及为深部验证钻孔的布设,提供了丰富的物探资料与信息。     

可控源音频大地电磁测深在隐伏断裂勘察中的应用研究

为了给城市工程建设规划提供基础地质资料,需查明区内断裂的准确位置、产状以及覆盖层厚度。利用CSAMT方法进行了勘察工作,为避免区内人文干扰和电磁的严重干扰,野外施工时采用了多种手段以保证观测数据的可信度;数据处理时首先利用五点平滑进行去噪处理,然后利用空间滤波消除静态效应,最后采用基于遗传算法的CSAMT全资料反演程序对野外数据进行反演。分析反演结果并结合已知地质资料,给出了区内断裂的准确位置等信息。     

二维大地电磁测深中静态效应分析

当地表浅层存在不均匀地质体时,会发生静态效应,对大地电磁测深数据资料产生畸变影响,从而影响到后期的资料处理和解释。本文运用有限单元法计算大地电磁测深二维正演,通过建立不同模型得到的响应特征,分析静态效应对大地电磁测深数据的影响。     

EH-4高频大地电磁测深在湖南某矿区的勘探应用

EH4电磁成像系统是一套双源型电磁法数据自动采集和处理的物探系统，它是CSAMT和MT的结合体。本文主要介绍了EH4的原理、特点和勘探效果。该系统运用于矿区异常地质体的勘察中，成功解译出了矿区存在的岩溶、断层破碎带及其他异常地质体的位置，为矿区的开采及安全防治工作提供了较好的依据，同时也为矿区勘察工作提供了—种新的勘察方法。     

EH-4高频大地电磁测深在湖南某矿区的勘探应用

EH4电磁成像系统是一套双源型电磁法数据自动采集和处理的物探系统,它是CSAMT和MT的结合体.本文主要介绍了EH4的原理、特点和勘探效果.该系统运用于矿区异常地质体的勘察中,成功解译出了矿区存在的岩溶、断层破碎带及其他异常地质体的位置,为矿区的开采及安全防治工作提供了较好的依据,同时也为矿区勘察工作提供了-种新的勘察方法.     

EH-4电磁测深在某地区隧道物探中的应用

随着科学技术的发展,EH-4大地电磁测深法勘探技术,得到了快速的发展。本文简单介绍了EH-4大地电磁测深的基本理论,并通过实际的野外施工工作,资料分析和异常解释,了解了该地区的地质情况,为后面隧道施工提供地质依据。     

音频大地电磁测深法在某隧道中的应用

本文主要讲述了音频大地电磁测深在某隧道的实际应用,从野外的施工到室内的数据处理和资料成图解释。依据音频大地电磁法(AMT)的带地形二维非线性共轭梯度(NLCG)反演结果,把电阻率异常分为Ⅴ类、Ⅳ类、Ⅲ类及Ⅱ类,分别对应极破碎岩体(Ⅴ级围岩)、破碎岩体(Ⅳ级围岩)、较破碎岩体(Ⅲ级围岩)和完整岩体(Ⅱ级围岩)。结合围岩分级结果,查明了隧道洞深附近岩性、断层破碎带及岩溶位置,对岩体完整性进行了评估。     

大地电磁相位张量分解特性

在大地电磁资料的分析中,其中相当大的一部分问题都是因为近地表电性结构水平非均匀性导致二维或三维的区域构造中水平均匀的正常电磁场发生畸变,从而对MT阻抗张量产生影响[1]。故研究MT阻抗张量畸变和分解方法对于反演解释的正确性有重要的意义。     

Automatic extraction of 1D barcodes from video scans for drone-assisted inventory management in warehousing applications

The widespread use of barcodes has significantly contributed to accurate, efficient and economic inventory management in warehouses and distribution centres. However, its efficiency has always been limited by the primary method of reading barcodes with a handheld laser scanner. Compared with this reading by line-of-sight at close proximity, vision-based barcode reading algorithms can further improve efficiency, particularly if accompanied by automated data collection platforms such as drones. This paper introduces algorithms that are able to automatically extract barcodes from video data, and verifies their feasibility and promise for inventory management in warehousing applications. Three key techniques corresponding to different recognition levels are proposed: For a known barcode region, a Harris corner detector and Hough transform-based algorithm is applied to quickly estimate the angle by which the frame area needs to rotate to orient the bars vertically for information extraction. Then, the idea of exploiting connectivity and geometry property of barcode areas is proposed to directly recognise multiple barcode regions in a single video frame to eliminate reading difficulties resulting from interactive influence of multiple juxtaposed barcodes, and to save computation time by only processing frame areas of interest for valid barcodes. In addition, a histogram difference-based fast extraction strategy is designed to further improve efficiency by reducing duplicate information processing. Finally, the performance of each technique is evaluated by analysing video data from a large logistics warehouse, demonstrating satisfactory performance in inventory management applications.     

The geographic accessibility of child care subsidies and evidence on the impact of subsidy receipt on childhood obesity

This paper examines the impact of the spatial accessibility of public human services agencies on the likelihood of receiving a child care subsidy among disadvantaged mothers with young children. In particular, we collect data on the location of virtually every human services agency in the US and use this information to calculate the approximate distance that families must travel from home in order to reach the nearest office that administers the subsidy application process. Using data from the Kindergarten cohort of the Early Childhood Longitudinal Study (ECLS-K), our results indicate that an increase in the distance to a public human services agency reduces the likelihood that a family receives a child care subsidy. Specifically, we estimate an elasticity of subsidy receipt with respect to distance of −0.13. The final section of the paper provides an empirical application in which we use variation in families’ travel distance to identify the causal effect of child care subsidies on children’s weight outcomes. Our instrumental variables estimates suggest that subsidized child care leads to sizeable increases in the prevalence of overweight and obesity among low-income children.