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Log4cxx在国产化平台的应用研究
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作者 陈家雄 梁聪 +2 位作者 徐明阳 秦子超 蒋中平 《电脑编程技巧与维护》 2024年第5期8-11,共4页
以国产化操作系统、数据库和硬件环境为基础,通过分析和示例详细阐述了使用及扩展Log4cxx日志框架实现日志信息记录和管理的具体方法,为国产化软件的开发和维护提供了高效、可靠、易用的日志解决方案。
关键词 log4cxx日志框架 国产化 操作系统 数据库
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大庆油田CIFLog测井数智云平台建设应用实践
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作者 李宁 刘英明 +2 位作者 王才志 原野 夏守姬 《大庆石油地质与开发》 CAS 北大核心 2024年第3期17-25,共9页
针对大庆油田生产中测井数据量大、类型多和数据来源复杂等问题,以中国石油天然气集团有限公司大型测井处理解释软件CIFLog为基础,以业务需求为主导,采用微服务架构和测井分布式云计算技术体系,研发测井大数据存储管理、中间服务层和云... 针对大庆油田生产中测井数据量大、类型多和数据来源复杂等问题,以中国石油天然气集团有限公司大型测井处理解释软件CIFLog为基础,以业务需求为主导,采用微服务架构和测井分布式云计算技术体系,研发测井大数据存储管理、中间服务层和云端测井处理解释应用等新功能,形成了大庆油田测井数智云应用平台。目前,平台已全面安装部署到大庆油田相关单位,应用效果显著。特别在大庆油田智能决策中心,平台直接用于重点水平井随钻地质导向的现场决策,大幅提升了Ⅰ类储层的钻遇率。未来平台将重点围绕新功能研发、油田数智化应用场景建设和标准化技术体系构建等开展工作,并将取得的成果及时推广复制到西南油田、塔里木油田等油气田。CIFLog云平台作为中国油气工业软件数智化建设应用的先行典范,必将发挥越来越重要的示范引领作用。 展开更多
关键词 大庆油田 CIFlog测井数智云平台 大数据 人工智能 微服务架构 分布式云计算
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基于改进LOG算子与Otsu算法结合的物体表面图像残损检测方法
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作者 李相格 《兰州交通大学学报》 CAS 2024年第1期59-63,共5页
针对物体表面残损区域存在明显的亮缺陷和不明显的暗缺陷这一特性,构建一种基于改进LOG算子与Otsu算法相结合的物体表面残损区域缺陷的边缘检测方法。首先,针对传统的LOG算子在检测图像亮缺陷边缘时检测结果不准确的问题,引入可根据图... 针对物体表面残损区域存在明显的亮缺陷和不明显的暗缺陷这一特性,构建一种基于改进LOG算子与Otsu算法相结合的物体表面残损区域缺陷的边缘检测方法。首先,针对传统的LOG算子在检测图像亮缺陷边缘时检测结果不准确的问题,引入可根据图像特性自动调整模糊因子的Wiener滤波代替传统LOG算子中的高斯滤波,以提高图像亮缺陷检测的精度;其次,针对检测图像暗缺陷边缘时结果不准确的问题,使用Otsu算法分析图像暗缺陷的灰度直方图来自动确定阈值,以提升暗缺陷边缘检测准确率;最后,采用像素加权平均融合算法对检测出的物体表面图像亮、暗缺陷边缘进行融合,以实现物体表面残损缺陷检测。实验结果表明:相较于单独使用改进的LOG算子和Otsu算法,采用加权融合的方法检测到的缺陷像素点数量与原始图片中基本一致,能够更准确地对图像中物体表面残损区域的亮、暗缺陷边缘进行检测。 展开更多
关键词 表面图像残损检测 WIENER滤波 log算子 OTSU算法 图像融合
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HiLog:OpenHarmony的高性能日志系统
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作者 吴圣垚 王枫 +4 位作者 武延军 凌祥 屈晟 罗天悦 吴敬征 《软件学报》 EI CSCD 北大核心 2024年第4期2055-2075,共21页
日志是计算机系统中记录事件状态信息的的重要载体,日志系统负责计算机系统的日志生成、收集和输出.OpenHarmony是新兴的、面向全设备、全场景的开源操作系统.在所述工作之前,包括日志系统在内OpenHarmony有许多关键子系统尚未构建,而Op... 日志是计算机系统中记录事件状态信息的的重要载体,日志系统负责计算机系统的日志生成、收集和输出.OpenHarmony是新兴的、面向全设备、全场景的开源操作系统.在所述工作之前,包括日志系统在内OpenHarmony有许多关键子系统尚未构建,而OpenHarmony的开源特性使第三方开发者可以为其贡献核心代码.为了解决Open Harmony日志系统缺乏的问题,主要开展如下工作:(1)分析当今主流日志系统的技术架构和优缺点;(2)基于OpenHarmony操作系统的异构设备互联特性设计HiLog日志系统模型规范;(3)设计并实现第1个面向OpenHarmony的日志系统HiLog,并贡献到OpenHarmony主线;(4)对HiLog日志系统的关键指标进行测试和对比试验.实验数据表明,在基础性能方面,HiLog和Log的日志写入阶段吞吐量分别为1500 KB/s和700 KB/s,相比Android日志系统吞吐量提升114%;在日志持久化方面,HiLog可以3.5%的压缩率进行持久化,并且丢包率小于6‰,远低于Log.此外,HiLog还具备数据安全、流量控制等新型实用能力. 展开更多
关键词 操作系统 日志系统 开源软件 数据安全 流量控制
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融合LoG特征的凸焊螺母检测算法
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作者 罗柏槐 李扬 +1 位作者 林熙烨 周梓斌 《计算机工程与应用》 CSCD 北大核心 2024年第10期332-340,共9页
针对目前汽车曲面零部件的紧固连接中常用的凸焊工艺中出现凸焊螺母的漏焊、错焊,以及主要依赖人工目测的低效检测方法等问题,提出了一种基于Faster-RCNN的凸焊螺母检测算法。以Faster-RCNN作为基础模型,针对模型在不同角度下螺母特征... 针对目前汽车曲面零部件的紧固连接中常用的凸焊工艺中出现凸焊螺母的漏焊、错焊,以及主要依赖人工目测的低效检测方法等问题,提出了一种基于Faster-RCNN的凸焊螺母检测算法。以Faster-RCNN作为基础模型,针对模型在不同角度下螺母特征各异且难以提取的问题,提出提取LoG特征和原图像自适应融合的方法,以增强模型对螺母特征的提取能力;引入特征金字塔(feature pyramid network,FPN)解决小目标难以被精确检测的问题;为了提升网络在复杂背景中的检测鲁棒性,在FPN中嵌入坐标注意力机制来提升网络对重点目标的关注;设计损失函数,提升训练效果,增强回归框中心点的回归精确度。实验结果表明,所提算法相比原算法,在IoU=0.75时凸焊螺母的检测精确率上升了8.65个百分点,达到90.11%,召回率上升了5.87个百分点,达到79.23%,相比原算法具有明显改善。 展开更多
关键词 目标检测 特征金字塔网络(FPN) 坐标注意力 log特征 区域建议网络(RPN)
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Integrated Geological and Geophysical Mapping for Groundwater Potential Studies at Ekwegbe-Agu and Environs, Enugu State, Nigeria
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作者 Charles Chibueze Ugbor Ugochukwu Kingsley Ogbodo Osita Kelechi Eze 《Open Journal of Geology》 CAS 2024年第4期513-547,共35页
The study integrates both the geological and geophysical mapping techniques for groundwater potential studies at Ekwegbe-Agu and the environs, Enugu state, Nigeria for optimal citing of borehole. Located in the Anambr... The study integrates both the geological and geophysical mapping techniques for groundwater potential studies at Ekwegbe-Agu and the environs, Enugu state, Nigeria for optimal citing of borehole. Located in the Anambra Basin between latitudes 6˚43'N and 6˚47'N and longitudes 7˚28'E and 7˚32'E, it is stratigraphycally underlain by, from bottom to top, the Enugu/Nkporo, Mamu and Ajali Formation respectively, a complex geology that make citing of productive borehole in the area problematic leading to borehole failure and dry holes due to inadequate sampling. The study adopted a field and analytic sampling approach, integrating field geological, electrical resistivity and self-potential methods. The software, SedLog v3.1, InterpexIx1Dv.3, and Surfer v10 were employed for the data integration and interpretation. The result of the geological field and borehole data shows 11 sedimentary facies consisting of sandstone, shales and heterolith of sandstone/shale, with the aquifer zone mostly prevalent in the more porous sand-dominated horizons. Mostly the AK and HK were the dominant curve types. An average of 6 geo-electric layers were delineated across all transects with resistivity values ranging from 25.42 - 105.85 Ωm, 186.38 - 3383.3 Ωm, and 2992 - 6286.4 Ωm in the Enugu, Mamu and Ajali Formations respectively. The resistivity of the main aquifer layer ranges from 1 to 500 Ωm. The aquifer thickness within the study area varies between 95 and 140 m. The western and northwestern part of the study area which is underlain mainly by the Ajali Formation showed the highest groundwater potential in the area and suitable for citing productive boreholes. 展开更多
关键词 SEISMIC Ekwegbe-Agu GROUNDWATER RESISTIVITY Field Mapping Borehole logging
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含零收益率的金融非对称Log-GARCH模型研究
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作者 裴浩天 车雪萌 +1 位作者 杨爱军 林金官 《运筹与管理》 CSCD 北大核心 2024年第3期177-183,共7页
在实际外汇市场中,由于诸如交易缺失、舍入误差等原因使得收益率序列中出现零值,常见GARCH族模型无法对含零收益率数据进行有效拟合,导致波动率估计结果产生较大偏差。为了更准确地估计汇率波动率,本文对含有零收益率的外汇数据进行建... 在实际外汇市场中,由于诸如交易缺失、舍入误差等原因使得收益率序列中出现零值,常见GARCH族模型无法对含零收益率数据进行有效拟合,导致波动率估计结果产生较大偏差。为了更准确地估计汇率波动率,本文对含有零收益率的外汇数据进行建模。首先运用不受条件方差为正限制的log-GARCH模型对汇率市场收益率数据进行拟合,同时提出一个处理含有零收益率的数据处理框架,即将零值视为缺失的观测值。然后通过结合QMLE方法和期望最大化(EM)算法对含缺失观测值的log-GARCH模型进行无偏估计。最后通过实证分析比较零收益率两种不同处理方法——非零值代替零值方法和将零值视为缺失值方法下波动率估计结果的差异。研究结果显示零收益率的存在会增加波动率的估计偏差,将非零值作为缺失值方法得到的估计结果更接近市场真实情况。 展开更多
关键词 汇率波动 log-GARCH模型 ARMA表达 缺失值
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基于改进LOG算子的雷达图像边缘检测算法
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作者 李平 张勇 +2 位作者 田忠彬 吕西昆 王晴晴 《空天预警研究学报》 CSCD 2024年第1期16-20,共5页
雷达图像中固定地物杂波的边缘轮廓对运动目标检测有重要作用.针对传统的高斯-拉普拉斯(LOG)边缘检测算法在对雷达图像进行边缘检测时对噪声敏感,易影响图像边缘轮廓信息的提取问题,提出了一种改进的LOG边缘检测算法.首先采用改进的均... 雷达图像中固定地物杂波的边缘轮廓对运动目标检测有重要作用.针对传统的高斯-拉普拉斯(LOG)边缘检测算法在对雷达图像进行边缘检测时对噪声敏感,易影响图像边缘轮廓信息的提取问题,提出了一种改进的LOG边缘检测算法.首先采用改进的均值滤波和双边滤波对图像进行平滑去噪;然后用拉普拉斯算子计算二阶方向导数,计算零交叉点得到图像的边缘位置信息,从而获得连续、完整的地物边缘轮廓;最后对雷达图像采用原始LOG和本文改进的LOG算法进行了对比实验.实验结果表明,在强地物杂波环境下,与原始LOG算法相比,改进的LOG算法提高了边缘的检测精度,改善了图像边缘连续性,从而可提高雷达目标的检测概率. 展开更多
关键词 雷达图像 高斯-拉普拉斯算子 边缘检测 均值滤波 双边滤波
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TRGATLog:基于日志时间图注意力网络的日志异常检测方法
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作者 陈旭 张硕 +1 位作者 景永俊 王叔洋 《计算机应用研究》 CSCD 北大核心 2024年第4期1034-1040,共7页
为解决现有日志异常检测方法往往只关注定量关系模式或顺序模式的单一特征,忽略了日志时间结构关系和不同特征之间的相互联系,导致较高的异常漏检率和误报率问题,提出基于日志时间图注意力网络的日志异常检测方法。首先,通过设计日志语... 为解决现有日志异常检测方法往往只关注定量关系模式或顺序模式的单一特征,忽略了日志时间结构关系和不同特征之间的相互联系,导致较高的异常漏检率和误报率问题,提出基于日志时间图注意力网络的日志异常检测方法。首先,通过设计日志语义和时间结构联合特征提取模块构建日志时间图,有效整合日志的时间结构关系和语义信息。然后,构造时间关系图注意力网络,利用图结构描述日志间的时间结构关系,自适应学习不同日志之间的重要性,进行异常检测。最后,使用三个公共数据集验证模型的有效性。大量实验结果表明,所提方法能够有效捕获日志时间结构关系,提高异常检测精度。 展开更多
关键词 异常检测 日志分析 图注意力网络 网络安全 日志时间图
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A Real-time Lithological Identification Method based on SMOTE-Tomek and ICSA Optimization
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作者 DENG Song PAN Haoyu +5 位作者 LI Chaowei YAN Xiaopeng WANG Jiangshuai SHI Lin PEI Chunyu CAI Meng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期518-530,共13页
In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on ... In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on machine learning and mud logging data is studied in this paper.This method can effectively utilize downhole parameters collected in real-time during drilling,to identify lithology in real-time and provide a reference for optimization of drilling parameters.Given the imbalance of lithology samples,the synthetic minority over-sampling technique(SMOTE)and Tomek link were used to balance the sample number of five lithologies.Meanwhile,this paper introduces Tent map,random opposition-based learning and dynamic perceived probability to the original crow search algorithm(CSA),and establishes an improved crow search algorithm(ICSA).In this paper,ICSA is used to optimize the hyperparameter combination of random forest(RF),extremely random trees(ET),extreme gradient boosting(XGB),and light gradient boosting machine(LGBM)models.In addition,this study combines the recognition advantages of the four models.The accuracy of lithology identification by the weighted average probability model reaches 0.877.The study of this paper realizes high-precision real-time lithology identification method,which can provide lithology reference for the drilling process. 展开更多
关键词 mud logging data real-time lithological identification improved crow search algorithm petroleum geological exploration SMOTE-Tomek
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Facies logging identification of intermediate-basic volcanic rocks in Huoshiling Formation of Songliao Basin
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作者 LI Yonggang YAN Bo 《Global Geology》 2024年第2期93-104,共12页
Volcanic oil and gas reservoirs are generally buried deep,which leads to a high whole-well coring cost,and the degree of development and size of reservoirs are controlled by volcanic facies.Therefore,accurately identi... Volcanic oil and gas reservoirs are generally buried deep,which leads to a high whole-well coring cost,and the degree of development and size of reservoirs are controlled by volcanic facies.Therefore,accurately identifying volcanic facies by logging curves not only provides the basis of volcanic reservoir prediction but also saves costs during exploration.The Songliao Basin is a‘fault-depression superimposed’composite basin with a typical binary filling structure.Abundant types of volcanic lithologies and facies are present in the Lishu fault depression.Volcanic activity is frequent during the sedimentary period of the Huoshiling Formation.Through systematic petrographic identification of the key exploratory well(SN165C)of the Lishu fault-depression,which is a whole-well core,it is found that the Huoshiling Formation in SN165C contains four facies and six subfacies,including the volcanic conduit facies(crypto explosive breccia subfacies),explosive facies(pyroclastic flow and thermal wave base subfacies),effusive facies(upper and lower subfacies),and volcanogenic sedimentary facies(pyroclastic sedimentary subfacies).Combining core,thin section,and logging data,the authors established identification markers and petrographic chart logging phases,and also interpreted the longitudinal variation in volcanic petro-graphic response characteristics to make the charts more applicable to this area's volcanic petrographic interpretation of the Huoshiling Formation.These charts can provide a basis for the further exploration and development of volcanic oil and gas in this area. 展开更多
关键词 Lishu fault-depression Huoshiling Formation volcanic lithofacies logging identification whole-coring well SN165C
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多模态遥感图像模板匹配Log-Gabor滤波方法
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作者 曹帆之 石添鑫 +2 位作者 韩开杨 汪璞 安玮 《测绘学报》 EI CSCD 北大核心 2024年第3期526-536,共11页
针对多模态遥感图像匹配难的问题,本文提出了一种基于Log-Gabor滤波的高精度匹配方法。该方法采用由粗到细的多层级密集匹配框架,无须进行特征点检测,避开了多模态图像特征点检测重复率低的问题,能够提取大量高精度匹配点对。本文方法... 针对多模态遥感图像匹配难的问题,本文提出了一种基于Log-Gabor滤波的高精度匹配方法。该方法采用由粗到细的多层级密集匹配框架,无须进行特征点检测,避开了多模态图像特征点检测重复率低的问题,能够提取大量高精度匹配点对。本文方法主要分为两步:首先,利用多尺度多角度Log-Gabor滤波器构建对图像间非线性辐射差异稳健的特征金字塔;然后,利用粗尺度的底层特征图进行密集模板匹配,提取大量粗粒度的特征匹配点对,在此基础上再利用特征金字塔,实现粗匹配点自下而上的逐层优化,完成高精度特征匹配点对的提取。同时,针对模板匹配滑窗运算效率不高的问题,提出了一种密集模板匹配的快速实现方式,有效减少了密集模板匹配的运算时间。本文使用多组不同模态的遥感图像进行试验,结果表明,本文方法能够克服图像间非线性辐射差异的影响,在正确匹配数目、匹配准确率与匹配精度上均优于现有多模态图像特征匹配方法。 展开更多
关键词 多模态遥感图像 特征匹配 log-GABOR滤波 模板匹配 非线性辐射差异
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LogRank++:一种高效的业务过程事件日志采样方法
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作者 刘聪 张帅鹏 +2 位作者 李会玲 何华 曾庆田 《计算机集成制造系统》 EI CSCD 北大核心 2024年第2期623-634,共12页
针对已有采样方法处理大规模事件日志时存在采样效率低的问题,提出一种高效的业务过程事件日志采样方法LogRank++。首先确定轨迹的重要性特征,然后对计算轨迹的重要性值进行排序,最后选择一组最重要的轨迹组成样本日志。综合采样质量和... 针对已有采样方法处理大规模事件日志时存在采样效率低的问题,提出一种高效的业务过程事件日志采样方法LogRank++。首先确定轨迹的重要性特征,然后对计算轨迹的重要性值进行排序,最后选择一组最重要的轨迹组成样本日志。综合采样质量和采样效率两方面来评估此采样方法的高效性。所提采样方法已在开源过程挖掘工具平台ProM中实现。实验分析表明,相比已有采样方法,在保证样本日志质量的前提下,LogRank++能够大幅提高日志采样效率。 展开更多
关键词 日志排序 日志采样 过程发现 质量评估
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基于CIFLog的铀裂变瞬发中子测井解释模块设计与研发
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作者 刘志锋 张寰宇 +2 位作者 丁成龙 李伟忠 魏振华 《铀矿地质》 CAS CSCD 2023年第5期824-830,共7页
铀矿γ测井是一种“间接测铀”方法,铀裂变瞬发中子测井是“直接测铀”方法,中子测井技术有其独特的优势,有望替代γ测井技术。经过多年的生产应用,γ测井已经有比较成熟的数据解释软件系统,但是铀裂变瞬发中子测井没有能够投入生产的... 铀矿γ测井是一种“间接测铀”方法,铀裂变瞬发中子测井是“直接测铀”方法,中子测井技术有其独特的优势,有望替代γ测井技术。经过多年的生产应用,γ测井已经有比较成熟的数据解释软件系统,但是铀裂变瞬发中子测井没有能够投入生产的应用软件。文章根据测井软件系统CIFLog的特点和结构组成,将铀矿测井的五点式反褶积分层解释法通过模块实现,集成于CIFLog系统中,再利用CIFLog测井解释模块,对解释数据进行可视化呈现,生成专业的成果展示,为铀裂变瞬发中子测井的应用提供可靠的应用软件系统。 展开更多
关键词 CIFlog 铀裂变瞬发中子测井 软件研发 铀矿 成果展示
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基于VideoLog可视化测井的井筒深度重采样方法研究
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作者 严正国 邹世娇 陈瑛 《工业控制计算机》 2023年第12期73-74,共2页
当前,VideoLog可视化测井视频的播放的基准线是时间。油气井的深度都在几千米不等,完整地播放一口油气井的测井视频需要十几小时。在测井资料解释阶段,处理测井视频不仅复杂,还浪费了大量的时间。为了节约时间,简化测井资料解释的步骤,... 当前,VideoLog可视化测井视频的播放的基准线是时间。油气井的深度都在几千米不等,完整地播放一口油气井的测井视频需要十几小时。在测井资料解释阶段,处理测井视频不仅复杂,还浪费了大量的时间。为了节约时间,简化测井资料解释的步骤,现提出一种测井视频以深度值为基准线进行播放索引的研究方法。该研究方法基于接箍识别和测井视频的处理,接箍识别提供接箍数据,视频处理提供视频帧数据,二者相结合获取视频每一帧的深度值,输出数据,在测井资料解释软件中实现可视化。通过Matlab搭建的实验平台进行实验,结果计算出了每一帧图像的深度数据并实现了与深度值索引,获得了预期的实验结果。 展开更多
关键词 可视化测井 测井资料 接箍
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Well logging evaluation of fine-grained hydrate-bearing sediment reservoirs: Considering the effect of clay content 被引量:1
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作者 Lin-Qi Zhu Jin Sun +4 位作者 Xue-Qing Zhou Qing-Ping Li Qi Fan Song-Lin Wu Shi-Guo Wu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期879-892,共14页
Hydrate reservoirs are different from the host reservoirs of all other fossil energy sources because the characteristics of hydrate reservoirs are generally controlled by deep-sea fine-grained sedimentation. In such r... Hydrate reservoirs are different from the host reservoirs of all other fossil energy sources because the characteristics of hydrate reservoirs are generally controlled by deep-sea fine-grained sedimentation. In such reservoirs, the reliability of the classical logging evaluation models established for diagenetic reservoirs is questionable. This study used well W8 in the Qiongdongnan Basin to explore the clay content, porosity, saturation, and hydrate-enriched layer identification of a logging-based hydrate reservoir, and it was found that considering the effect of the clay content on the log response is necessary in the logging evaluation of hydrate reservoirs. In the evaluation of clay content, a method based on the optimization inversion method can obtain a more reliable clay content than other methods. Fine-grained sediment reservoirs have a high clay content, and the effect of clay on log responses must be considered when calculating porosity. In addition, combining density logging and neutron porosity logging data can obtain the best porosity calculation results, and the porosity calculation method based on sonic logging predicted that the porosity of the studied reservoir was low. It was very effective to identify hydrate layers based on resistivity, but the clay distribution and pore structure will also affect the relationship between resistivity, porosity and saturation, and it was suggested that the factors effecting the resistivity of different layers should be considered in the saturation evaluation and that a suitable model should be selected. This study also considered the lack of clarity of the relationships among the lithology, physical properties, hydrate-bearing occurrence properties, and log response properties of hydrate reservoirs and the lack of specialized petrophysical models. This research can directly help to improve hydrate logging evaluation. 展开更多
关键词 Gas hydrate Well logging Porosity Saturation Shale distribution form
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Unsupervised Log Anomaly Detection Method Based on Multi-Feature 被引量:1
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作者 Shiming He Tuo Deng +2 位作者 Bowen Chen R.Simon Sherratt Jin Wang 《Computers, Materials & Continua》 SCIE EI 2023年第7期517-541,共25页
Log anomaly detection is an important paradigm for system troubleshooting.Existing log anomaly detection based on Long Short-Term Memory(LSTM)networks is time-consuming to handle long sequences.Transformer model is in... Log anomaly detection is an important paradigm for system troubleshooting.Existing log anomaly detection based on Long Short-Term Memory(LSTM)networks is time-consuming to handle long sequences.Transformer model is introduced to promote efficiency.However,most existing Transformer-based log anomaly detection methods convert unstructured log messages into structured templates by log parsing,which introduces parsing errors.They only extract simple semantic feature,which ignores other features,and are generally supervised,relying on the amount of labeled data.To overcome the limitations of existing methods,this paper proposes a novel unsupervised log anomaly detection method based on multi-feature(UMFLog).UMFLog includes two sub-models to consider two kinds of features:semantic feature and statistical feature,respectively.UMFLog applies the log original content with detailed parameters instead of templates or template IDs to avoid log parsing errors.In the first sub-model,UMFLog uses Bidirectional Encoder Representations from Transformers(BERT)instead of random initialization to extract effective semantic feature,and an unsupervised hypersphere-based Transformer model to learn compact log sequence representations and obtain anomaly candidates.In the second sub-model,UMFLog exploits a statistical feature-based Variational Autoencoder(VAE)about word occurrence times to identify the final anomaly from anomaly candidates.Extensive experiments and evaluations are conducted on three real public log datasets.The results show that UMFLog significantly improves F1-scores compared to the state-of-the-art(SOTA)methods because of the multi-feature. 展开更多
关键词 System log anomaly detection semantic features statistical features TRANSFORMER
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A deep kernel method for lithofacies identification using conventional well logs 被引量:1
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作者 Shao-Qun Dong Zhao-Hui Zhong +5 位作者 Xue-Hui Cui Lian-Bo Zeng Xu Yang Jian-jun Liu Yan-Ming Sun jing-Ru Hao 《Petroleum Science》 SCIE EI CAS CSCD 2023年第3期1411-1428,共18页
How to fit a properly nonlinear classification model from conventional well logs to lithofacies is a key problem for machine learning methods.Kernel methods(e.g.,KFD,SVM,MSVM)are effective attempts to solve this issue... How to fit a properly nonlinear classification model from conventional well logs to lithofacies is a key problem for machine learning methods.Kernel methods(e.g.,KFD,SVM,MSVM)are effective attempts to solve this issue due to abilities of handling nonlinear features by kernel functions.Deep mining of log features indicating lithofacies still needs to be improved for kernel methods.Hence,this work employs deep neural networks to enhance the kernel principal component analysis(KPCA)method and proposes a deep kernel method(DKM)for lithofacies identification using well logs.DKM includes a feature extractor and a classifier.The feature extractor consists of a series of KPCA models arranged according to residual network structure.A gradient-free optimization method is introduced to automatically optimize parameters and structure in DKM,which can avoid complex tuning of parameters in models.To test the validation of the proposed DKM for lithofacies identification,an open-sourced dataset with seven con-ventional logs(GR,CAL,AC,DEN,CNL,LLD,and LLS)and lithofacies labels from the Daniudi Gas Field in China is used.There are eight lithofacies,namely clastic rocks(pebbly,coarse,medium,and fine sand-stone,siltstone,mudstone),coal,and carbonate rocks.The comparisons between DKM and three commonly used kernel methods(KFD,SVM,MSVM)show that(1)DKM(85.7%)outperforms SVM(77%),KFD(79.5%),and MSVM(82.8%)in accuracy of lithofacies identification;(2)DKM is about twice faster than the multi-kernel method(MSVM)with good accuracy.The blind well test in Well D13 indicates that compared with the other three methods DKM improves about 24%in accuracy,35%in precision,41%in recall,and 40%in F1 score,respectively.In general,DKM is an effective method for complex lithofacies identification.This work also discussed the optimal structure and classifier for DKM.Experimental re-sults show that(m_(1),m_(2),O)is the optimal model structure and linear svM is the optimal classifier.(m_(1),m_(2),O)means there are m KPCAs,and then m2 residual units.A workflow to determine an optimal classifier in DKM for lithofacies identification is proposed,too. 展开更多
关键词 Lithofacies identification Deepkernel method Well logs Residual unit Kernel principal component analysis Gradient-free optimization
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Contamination Identification of Lentinula Edodes Logs Based on Improved YOLOv5s 被引量:1
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作者 Xuefei Chen Wenhui Tan +3 位作者 Qiulan Wu Feng Zhang Xiumei Guo Zixin Zhu 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期3143-3157,共15页
In order to improve the accuracy and efficiency of Lentinula edodes logs contamination identification,an improved YOLOv5s contamination identification model for Lentinula edodes logs(YOLOv5s-CGGS)is proposed in this p... In order to improve the accuracy and efficiency of Lentinula edodes logs contamination identification,an improved YOLOv5s contamination identification model for Lentinula edodes logs(YOLOv5s-CGGS)is proposed in this paper.Firstly,a CA(coordinate attention)mechanism is introduced in the feature extraction network of YOLOv5s to improve the identifiability of Lentinula edodes logs contamination and the accuracy of target localiza-tion.Then,the CIoU(Complete-IOU)loss function is replaced by an SIoU(SCYLLA-IoU)loss function to improve the model’s convergence speed and inference accuracy.Finally,the GSConv and GhostConv modules are used to improve and optimize the feature fusion network to improve identification efficiency.The method in this paper achieves values of 97.83%,97.20%,and 98.20%in precision,recall,and mAP@0.5,which are 2.33%,3.0%,and 1.5%better than YOLOv5s,respectively.mAP@0.5 is better than YOLOv4,Ghost-YOLOv4,and Mobilenetv3-YOLOv4(improved by 4.61%,5.16%,and 6.04%,respectively),and the FPS increased by two to three times. 展开更多
关键词 Lentinula edodes logs contamination identification deep learning attention mechanism loss function
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Advantage of log odds of positive lymph nodes in prognostic evaluation of patients with early-onset colon cancer 被引量:1
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作者 Heng-Bo Xia Chen Chen +2 位作者 Zhi-Xing Jia Liang Li A-Man Xu 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第11期2430-2444,共15页
BACKGROUND Colon cancer(CC)is one of the most common cancers of the digestive tract,the third most common cancer worldwide,and the second most common cause of cancer-related deaths.Previous studies have demonstrated a... BACKGROUND Colon cancer(CC)is one of the most common cancers of the digestive tract,the third most common cancer worldwide,and the second most common cause of cancer-related deaths.Previous studies have demonstrated a higher risk of lymph node metastasis(LNM)in young patients with CC.It might be reasonable to treat patients with early-onset locally advanced CC with extended lymph node dissection.However,few studies have focused on early-onset CC(ECC)patients with LNM.At present,the methods of predicting and evaluating the prognosis of ECC patients with LNM are controversial.From the data of patients with CC obtained from the Surveillance,Epidemiology,and End Results(SEER)database,data of young patients with ECC(≤50 years old)was screened.Patients with unknown data were excluded from the study,while the remaining patients were included.The patients were randomly divided into a training group(train)and a testing group(test)in the ratio of 7:3,while building the model.The model was constructed by the training group and verified by the testing group.Using multiple Cox regression models to compare the prediction efficiency of LNM indicators,nomograms were built based on the best model selected for overall survival(OS)and cause-specific survival(CSS).In the two groups,the performance of the nomogram was evaluated by constructing a calibration plot,time-dependent area under the curve(AUC),and decision curve analysis.Finally,the patients were grouped based on the risk score predicted by the prognosis model,and the survival curve was constructed after comparing the survival status of the high and low-risk groups.RESULTS Records of 26922 ECC patients were screened from the SEER database.N classification,positive lymph nodes(PLN),lymph node ratio(LNR)and log odds of PLN(LODDS)were considered to be independent predictors of OS and CSS.In addition,independent risk factors for OS included gender,race,marital status,primary site,histology,grade,T,and M classification,while the independent prognostic factors for CSS included race,marital status,primary site,grade,T,and M classification.The prediction model including LODDS is composed of minimal Akaike information criterion,maximal concordance indexes,and AUCs.Factors including gender,race,marital status,primary site,histology,grade,T,M classification,and LODDS were integrated into the OS nomogram,while race,marital status,primary site,grade,T,M classification,and LODDS were included into the CSS nomogram.The nomogram representing both cohorts had been successfully verified in terms of prediction accuracy and clinical practicability.CONCLUSION LODDS is superior to N-stage,PLN,and LNR of ECC.The nomogram containing LODDS might be helpful in tumor evaluation and clinical decision-making,since it provides an appropriate prediction of ECC. 展开更多
关键词 Early-onset colon cancer log odds of positive lymph nodes Lymph node metastasis NOMOGRAM Prognosis Surveillance Epidemiology and End Results
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