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Family gathering
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作者 江丽 《疯狂英语(初中天地)》 2025年第9期6-7,共2页
一、请根据录音,填写单词。二、听对话,选择正确的答案。1.Who is coming for dinner?A.Friends.B.Aunt and uncle.C.Grandma and grandpa.2.What does Dad offer to do at the beginning?A.Go shopping.B.Set the table.C.Cook the fish.
关键词 DINNER friends table grandpa AUNT GRANDMA family gathering UNCLE
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Event-Driven Attention Network:A Cross-Modal Framework for Efficient Image-Text Retrieval in Mass Gathering Events
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作者 Kamil Yasen Heyan Jin +4 位作者 Sijie Yang Li Zhan Xuyang Zhang Ke Qin Ye Li 《Computers, Materials & Continua》 2025年第5期3277-3301,共25页
Research on mass gathering events is critical for ensuring public security and maintaining social order.However,most of the existing works focus on crowd behavior analysis areas such as anomaly detection and crowd cou... Research on mass gathering events is critical for ensuring public security and maintaining social order.However,most of the existing works focus on crowd behavior analysis areas such as anomaly detection and crowd counting,and there is a relative lack of research on mass gathering behaviors.We believe real-time detection and monitoring of mass gathering behaviors are essential formigrating potential security risks and emergencies.Therefore,it is imperative to develop a method capable of accurately identifying and localizing mass gatherings before disasters occur,enabling prompt and effective responses.To address this problem,we propose an innovative Event-Driven Attention Network(EDAN),which achieves image-text matching in the scenario of mass gathering events with good results for the first time.Traditional image-text retrieval methods based on global alignment are difficult to capture the local details within complex scenes,limiting retrieval accuracy.While local alignment-based methods aremore effective at extracting detailed features,they frequently process raw textual features directly,which often contain ambiguities and redundant information that can diminish retrieval efficiency and degrade model performance.To overcome these challenges,EDAN introduces an Event-Driven AttentionModule that adaptively focuses attention on image regions or textual words relevant to the event type.By calculating the semantic distance between event labels and textual content,this module effectively significantly reduces computational complexity and enhances retrieval efficiency.To validate the effectiveness of EDAN,we construct a dedicated multimodal dataset tailored for the analysis of mass gathering events,providing a reliable foundation for subsequent studies.We conduct comparative experiments with other methods on our dataset,the experimental results demonstrate the effectiveness of EDAN.In the image-to-text retrieval task,EDAN achieved the best performance on the R@5 metric,while in the text-to-image retrieval task,it showed superior results on both R@10 and R@5 metrics.Additionally,EDAN excelled in the overall Rsummetric,achieving the best performance.Finally,ablation studies further verified the effectiveness of event-driven attention module. 展开更多
关键词 Mass gathering events image-text retrieval attention mechanism
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Data Gathering Based on Hybrid Energy Efficient Clustering Algorithm and DCRNN Model in Wireless Sensor Network
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作者 Li Cuiran Liu Shuqi +1 位作者 Xie Jianli Liu Li 《China Communications》 2025年第3期115-131,共17页
In order to solve the problems of short network lifetime and high data transmission delay in data gathering for wireless sensor network(WSN)caused by uneven energy consumption among nodes,a hybrid energy efficient clu... In order to solve the problems of short network lifetime and high data transmission delay in data gathering for wireless sensor network(WSN)caused by uneven energy consumption among nodes,a hybrid energy efficient clustering routing base on firefly and pigeon-inspired algorithm(FF-PIA)is proposed to optimise the data transmission path.After having obtained the optimal number of cluster head node(CH),its result might be taken as the basis of producing the initial population of FF-PIA algorithm.The L′evy flight mechanism and adaptive inertia weighting are employed in the algorithm iteration to balance the contradiction between the global search and the local search.Moreover,a Gaussian perturbation strategy is applied to update the optimal solution,ensuring the algorithm can jump out of the local optimal solution.And,in the WSN data gathering,a onedimensional signal reconstruction algorithm model is developed by dilated convolution and residual neural networks(DCRNN).We conducted experiments on the National Oceanic and Atmospheric Administration(NOAA)dataset.It shows that the DCRNN modeldriven data reconstruction algorithm improves the reconstruction accuracy as well as the reconstruction time performance.FF-PIA and DCRNN clustering routing co-simulation reveals that the proposed algorithm can effectively improve the performance in extending the network lifetime and reducing data transmission delay. 展开更多
关键词 CLUSTERING data gathering DCRNN model network lifetime wireless sensor network
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“Spring Blossoms”ASEAN-China Lady Cultural Gathering Held in Beijing
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《International Understanding》 2025年第1期42-42,共1页
On 5 March,2025,the"Spring Blossoms"ASEAN-China Lady Cultural Gathering was held at the White Pagoda Academy in Beijing.The event was co-hosted by the ASEAN-China Centre and the Beijing People's Associat... On 5 March,2025,the"Spring Blossoms"ASEAN-China Lady Cultural Gathering was held at the White Pagoda Academy in Beijing.The event was co-hosted by the ASEAN-China Centre and the Beijing People's Association for Friendship with Foreign Countries. 展开更多
关键词 Beijing Peoples Association Friendship Foreign Countries white pagoda academy Spring Blossoms ASEAN China Lady Cultural gathering ASEAN China Centre BEIJING White Pagoda Academy
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基于对标管理和节点分析的煤层气集气系统站场工艺优化方法
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作者 孟凡华 张博 +3 位作者 刘松群 吴春升 屈丽彬 王子辉 《油气田地面工程》 2026年第1期60-65,共6页
在企业管理活动中,对标管理和节点分析是企业不断改进和获得竞争优势的最重要管理方式。山西煤层气分公司自2021年起,按照中国石油天然气股份有限公司煤层气田管理指标开展对标管理工作,发现了综合用能高的主要问题。为进一步提升煤层... 在企业管理活动中,对标管理和节点分析是企业不断改进和获得竞争优势的最重要管理方式。山西煤层气分公司自2021年起,按照中国石油天然气股份有限公司煤层气田管理指标开展对标管理工作,发现了综合用能高的主要问题。为进一步提升煤层气田地面系统运行管理水平,构建了一套具有二级节点、41项管控参数的煤层气集气系统井站管理体系,建立了节点分析和对标管理融合的工作流程,在此基础上,通过分析和论证,实施站场优化4处,实现沁水盆地煤层气田站场运行参数逐步提升。2021至2023年单位气田气生产综合能耗、单位气田气采集输综合能耗、单位气田气处理综合能耗逐年下降,完成了2021年的能耗指标低于平均值到2023年指标接近先进值的转变。 展开更多
关键词 煤层气 集气系统 对标管理 节点分析 工艺优化
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建成环境对网约车-地铁组合出行的非线性影响分析
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作者 潘义勇 王聪伟 +1 位作者 宋文超 贾熙来 《重庆交通大学学报(自然科学版)》 北大核心 2026年第1期53-62,共10页
为探究建成环境对网约车-地铁组合出行需求的非线性影响,首先,基于网约车订单轨迹数据,识别、筛选出地铁站500 m缓冲区内接入、接出的网约车订单数据;其次,建立网约车-地铁组合出行聚集缓冲区,根据“5D”原则构建建成环境变量指标,并将... 为探究建成环境对网约车-地铁组合出行需求的非线性影响,首先,基于网约车订单轨迹数据,识别、筛选出地铁站500 m缓冲区内接入、接出的网约车订单数据;其次,建立网约车-地铁组合出行聚集缓冲区,根据“5D”原则构建建成环境变量指标,并将组合出行数据和变量数据对应至网格;最后,利用XGBoost模型分析建成环境对网约车-地铁组合出行的非线性影响,并识别出关键因素。研究结果表明:XGBoost模型的拟合效果整体优于选用的其他模型;到达市中心距离和人口密度是影响网约车-地铁组合出行的关键因素,它们的相对重要性在接入组合出行中超过45%,在接出组合出行中达到40%;建成环境对网约车-地铁不同组合出行模式的影响表现出显著的非线性特征,并展现出相应的阈值效应,到达市中心距离、人口密度和路网密度对组合出行表现出负向影响,商业设施对组合出行呈现出正向影响,金融设施的数量在16个时为关键阈值点,低于该值表现为正向影响,高于该值表现为负向影响,此外,不同时段公交站对组合出行表现出的非线性特征,表明网约车与城市公交之间具有复杂动态关系。 展开更多
关键词 交通工程 组合出行 XGBoost模型 非线性关系 建成环境 网约车聚集缓冲区
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Kirchhoff PSDM angle-gather generation based on the traveltime gradient 被引量:1
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作者 刘少勇 王华忠 +2 位作者 刘太臣 胡英 张才 《Applied Geophysics》 SCIE CSCD 2015年第1期64-72,121,122,共11页
Angle-domain common-image gathers(ADCIGs) are the basic data in migration velocity analysis(MVA) and amplitude variation with angle(AVA) analysis. We propose a common-angle gather-generating scheme using Kirchho... Angle-domain common-image gathers(ADCIGs) are the basic data in migration velocity analysis(MVA) and amplitude variation with angle(AVA) analysis. We propose a common-angle gather-generating scheme using Kirchhoff PSDM based on the traveltime gradient field. The scheme includes three major operations:(1) to calculate the traveltime field of the source and the receiver based on the dynamic programming approach;(2) to obtain the refl ection angle according to the traveltime gradient field in the image space; and(3) to generate the ADCIGs during the migration process. Because of the computation approach, the method for generating ADCIGs is superior to conventional ray-based methods. We use the proposed ADCIGs generation method in 3D large-scale seismic data. The key points of the method are the following.(1) We use common-shot datasets for migration,(2) we load traveltimes based on the shot aperture, and(3) we use the MPI and Open Mp memory sharing to decrease the amount of input and output(I/O). Numerical examples using synthetic data suggest that the ADCIGs improve the quality of the velocity and the effectiveness of the 3D angle-gather generation scheme. 展开更多
关键词 ADCIGs Kirchhoff prestack depth migration angle domain common-image gathers migration velocity analysis
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聚合物驱油集输管道的腐蚀原因
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作者 张维智 高博文 +3 位作者 闫茂成 王海涛 唐德志 韩恩厚 《腐蚀与防护》 北大核心 2026年第1期68-73,共6页
大庆油田广泛应用聚合物采油技术,注入水中含有大量微生物,聚合物驱集输管道发生腐蚀穿孔,引发泄漏事故。采用扫描电子显微镜(SEM)及能谱(EDS)、X射线衍射(XRD)及激光共聚焦显微镜等分析了管道腐蚀特征,使用rRNA测序检测微生物的种属,... 大庆油田广泛应用聚合物采油技术,注入水中含有大量微生物,聚合物驱集输管道发生腐蚀穿孔,引发泄漏事故。采用扫描电子显微镜(SEM)及能谱(EDS)、X射线衍射(XRD)及激光共聚焦显微镜等分析了管道腐蚀特征,使用rRNA测序检测微生物的种属,探究了集输管道的主要腐蚀类型及微生物腐蚀的识别特征。结果表明:管道输送介质的矿化度和溶解性固体总量(TDS)高,CO_(3)^(2-)、HCO_(3)^(-)质量浓度均超过2000 mg/L,介质和腐蚀产物中微生物富集,管道内壁形成大量锈瘤,锈瘤表面S质量分数高达16.62%,锈瘤外壳S质量分数为6.60%,硫酸盐还原菌导致油田聚合物驱管道发生严重微生物腐蚀和垢下腐蚀。 展开更多
关键词 集输管道 微生物腐蚀 聚合物驱 垢下腐蚀 锈瘤
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GSVM:一种支持Gather/Scatter的向量存储器
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作者 陈海燕 刘胜 吴健虢 《国防科技大学学报》 EI CAS CSCD 北大核心 2020年第3期1-8,共8页
宽单指令多数据流(Single Instruction Multiple Data,SIMD)架构数字信号处理器一般都能高效支持地址连续或等距跨步等规则应用的向量访存,但对于科学与工程计算中广泛存在的不规则应用的数据访存则带宽利用率往往较低,从而大幅降低了... 宽单指令多数据流(Single Instruction Multiple Data,SIMD)架构数字信号处理器一般都能高效支持地址连续或等距跨步等规则应用的向量访存,但对于科学与工程计算中广泛存在的不规则应用的数据访存则带宽利用率往往较低,从而大幅降低了其整体运算能效。为了提高不规则应用的向量访存性能,基于某SIMD数字信号处理器的体系结构,设计了一种支持Gather/Scatter访存的向量存储器GSVM。通过设计与SIMD宽度相匹配的向量地址计算单元和合适深度的冲突缓冲器阵列,实现了Gather/Scatter指令向量地址计算、仲裁与缓存的全流水访存操作。实验结果表明,相比以前不支持Gather/Scatter访存的存储器,GSVM在增加22%的硬件代价基础上,基于稀疏矩阵向量乘的测试程序集获得了2~8的性能加速比。 展开更多
关键词 单指令多数据流 gather/Scatter 向量随机访存 访存冲突
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某气田集输管道的清管作业规律
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作者 王小魏 黄仕林 +1 位作者 青鹏 蒲阳凤 《腐蚀与防护》 北大核心 2026年第1期54-58,共5页
在起伏地区输气管道中,管线积液情况的分析、清管风险位置的判断以及清管器运行速度的精准控制对清管作业的顺利开展至关重要。目前,某气田集输管道的清管作业主要根据经验判断清管器运行状态,难以准确分析清管规律。为此,基于现场清管... 在起伏地区输气管道中,管线积液情况的分析、清管风险位置的判断以及清管器运行速度的精准控制对清管作业的顺利开展至关重要。目前,某气田集输管道的清管作业主要根据经验判断清管器运行状态,难以准确分析清管规律。为此,基于现场清管器实际运行情况,优选适用于该气田集输管道的气液两相流模型,并建立OLGA仿真模型,系统分析管道积液分布规律。通过模拟优化清管器运行速度及控制气量,预测易发生积液与堵塞的高风险管段,并提出清管批处理作业的改进措施。 展开更多
关键词 集输管道 运行速度 OLGA模型 清管规律
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基于CNNs和Transformer混合的茶田路径分割模型
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作者 麦彦恒 黄浩宜 +3 位作者 郑佳祺 骆泽丰 廖仲樑 唐劲驰 《中国农机化学报》 北大核心 2026年第2期217-225,共9页
随着农业无人车的茶田自动导航技术愈加重要,为提供在边缘计算中快速推理的实时导航路径计算,提出一种新的基于CNN和Transformer混合策略的茶田路径分割模型TCT—YOLO。在农情差异化的背景下,TCT—YOLO基于YOLOv8实现Conv块(TCB)和Trans... 随着农业无人车的茶田自动导航技术愈加重要,为提供在边缘计算中快速推理的实时导航路径计算,提出一种新的基于CNN和Transformer混合策略的茶田路径分割模型TCT—YOLO。在农情差异化的背景下,TCT—YOLO基于YOLOv8实现Conv块(TCB)和Transformer块(TTB)可堆栈式部署,在茶田道路分割任务中有更优秀的泛化能力,样本总体平均交并比mIoU提高4.8%。Transformer块在该任务中可能导致过拟合和传播梯度爆炸,在TCB与TTB中采用Leaky ReLU激活函数和Layer Normalization。在下游任务中与各个模型进行对比,所提模型推理速度更快、检测精度更高。关注到YOLO模型采取FPN的方式提取特征从而忽略跨层信息损失的问题,采用信息聚集—分发(GD)机制改进,通过在全局视野上对不同层级的特征聚集融合并分发注入到不同层级中,总体平均交并比提升2.2%。 展开更多
关键词 茶田路径分割 实例分割 信息聚集—分发 边缘计算 轻量化模型
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Environment and Human Behaviors——Taking “The Acorn Gatherer” as a Case Study
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作者 王富银 《海外英语》 2012年第11X期190-191,共2页
Human living environment interacts with human behaviors.Environment to some degree determines human behaviors which in return reshape and sustain the dynamic environment.Taking Richard Jefferies' The Acorn Gathere... Human living environment interacts with human behaviors.Environment to some degree determines human behaviors which in return reshape and sustain the dynamic environment.Taking Richard Jefferies' The Acorn Gatherer as a case study,this paper makes an argument that the behaviors of the villagers in the story can be more adequately interpreted in view of the backward countryside environment,and the same is true with the author Richard Jefferies' non-interference in the omniscient third-person point of view in writing the story.It is Richard Jefferies' family environment that makes up his viewpoint of writing,reflecting his critical loving of the countryside,where lives boom and conventions are extremely followed. 展开更多
关键词 The ACORN gatherer a CASE STUDY INTERACTIONS envir
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Social Conventions and Human Tragedy—On Richard Jefferies's The Acorn Gatherer
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作者 张韵菲 《海外英语》 2013年第17期222-224,共3页
The Acorn Gatherer by Richard Jefferies is an allegorical tragedy, in which a nameless boy, born out of wedlock, is viewed as a sort of icon of sin, and is ultimately driven to death by the rigid and unforgiving socia... The Acorn Gatherer by Richard Jefferies is an allegorical tragedy, in which a nameless boy, born out of wedlock, is viewed as a sort of icon of sin, and is ultimately driven to death by the rigid and unforgiving social conventions. 展开更多
关键词 The ACORN gatherer RICHARD Jefferies HUMAN TRAGEDY
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油气集输管道阴极保护绝缘性能测试方法比较
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作者 张晓虎 高倩钰 +1 位作者 唐德志 李德明 《腐蚀与防护》 北大核心 2026年第1期59-62,共4页
针对不同类型的绝缘失效问题,对比分析不同绝缘性能测试方法的优缺点,提出电位法、馈电法、电流法、绝缘接头测试仪法及其组合方法。现场验证结果表明,组合测试方法具有测试准确度高、抗干扰、测试范围广等优点,可作为油气集输管道及场... 针对不同类型的绝缘失效问题,对比分析不同绝缘性能测试方法的优缺点,提出电位法、馈电法、电流法、绝缘接头测试仪法及其组合方法。现场验证结果表明,组合测试方法具有测试准确度高、抗干扰、测试范围广等优点,可作为油气集输管道及场站阴极保护绝缘性能测试的推荐做法。 展开更多
关键词 油气集输管道 阴极保护 绝缘失效 电位法 电流环法 绝缘接头测试仪法
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Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field 被引量:4
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作者 En-Bin Liu Shen Huang +3 位作者 Ding-Chao Tian Lai-Min Shi Shan-Bi Peng He Zheng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1257-1274,共18页
During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow... During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%. 展开更多
关键词 Shale gas Gas gathering pipeline ELBOW EROSION CFD
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基于多模态双协同Gather Transformer网络的虚假信息检测方法 被引量:1
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作者 向旺 王金光 +1 位作者 王一飞 钱胜胜 《计算机科学》 CSCD 北大核心 2024年第12期242-249,共8页
社交媒体网站是人们在日常生活中分享信息、表达和交换意见的便捷平台。随着用户数量的不断增加,社交媒体网站上出现了大量的信息数据。然而,由于用户没有检查共享信息的可靠性,这些信息的真实性难以保证,从而导致大量虚假信息在社交媒... 社交媒体网站是人们在日常生活中分享信息、表达和交换意见的便捷平台。随着用户数量的不断增加,社交媒体网站上出现了大量的信息数据。然而,由于用户没有检查共享信息的可靠性,这些信息的真实性难以保证,从而导致大量虚假信息在社交媒体上广泛传播。然而,现有方法大多存在以下局限性:1)大多数方法通过简单提取文本与视觉特征,将其拼接后得到多模态特征来进行虚假信息判断,忽略了模态间和模态内细粒度内在联系,缺乏对关键信息的检索和筛选;2)多模态信息间缺乏指导性的特征提取,文本和视觉等特征之间缺乏交互增强,对多模态信息的理解不足。为了应对这些挑战,提出了一种新颖的基于多模态双协同Gather Transformer网络(Multimodal Dual-Collaborative Gather Transformer Network,MDCGTN)的虚假信息检测方法。在MDCGTN模型中,通过文本-视觉编码网络对文本和视觉信息的特征表示进行提取,将获得的视觉和文本特征表示输入多模态Gather Transformer网络进行多模态信息融合,使用Gather机制提取关键信息,充分捕捉和融合模态内和模态间细粒度关系。此外,设计了一个双协同机制对社交媒体帖子的多模态信息进行整合,以实现模态之间信息的交互和增强。在两个公开可用的基准数据集上进行了大量实验,结果表明,与现有的先进基准方法相比,所提方法准确率明显提升,证明了其对于虚假信息检测的优越性能。 展开更多
关键词 多模态 虚假信息检测 社交媒体 gather Transformer网络
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Local events-based fast RTM surface-offset gathers via dip-guided interpolation 被引量:3
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作者 Yang Zhao Feng-Lin Niu +3 位作者 Lei Fu Cheng Cheng Jin-Hong Chen Shou-Dong Huo 《Petroleum Science》 SCIE CAS CSCD 2021年第3期773-782,共10页
Reverse Time Migration(RTM)Surface Ofset Gathers(SOGs)are demonstrated to deliver more superior residual dip information than ray-based approaches.It appears more powerful in complex geological settings,such as salt a... Reverse Time Migration(RTM)Surface Ofset Gathers(SOGs)are demonstrated to deliver more superior residual dip information than ray-based approaches.It appears more powerful in complex geological settings,such as salt areas.Still,the computational cost of constructing RTM SOGs is a big challenge in applying it to 3D feld data.To tackle this challenge,we propose a novel method using dips of local events as a guide for RTM gather interpolation.The residual-dip information of the SOGs is created by connecting local events from depth-domain to time-domain via ray tracing.The proposed method is validated by a synthetic experiment and a feld example.It mitigates the computational cost by an order of magnitude while producing comparable results as fully computed RTM SOGs. 展开更多
关键词 Surface-ofset gathers Reverse-time migration Dip-guided interpolation Reduced costs Local-event raytracing
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Data Gathering in Wireless Sensor Networks Via Regular Low Density Parity Check Matrix 被引量:1
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作者 Xiaoxia Song Yong Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期83-91,共9页
A great challenge faced by wireless sensor networks(WSNs) is to reduce energy consumption of sensor nodes. Fortunately, the data gathering via random sensing can save energy of sensor nodes. Nevertheless, its randomne... A great challenge faced by wireless sensor networks(WSNs) is to reduce energy consumption of sensor nodes. Fortunately, the data gathering via random sensing can save energy of sensor nodes. Nevertheless, its randomness and density usually result in difficult implementations, high computation complexity and large storage spaces in practical settings. So the deterministic sparse sensing matrices are desired in some situations. However,it is difficult to guarantee the performance of deterministic sensing matrix by the acknowledged metrics. In this paper, we construct a class of deterministic sparse sensing matrices with statistical versions of restricted isometry property(St RIP) via regular low density parity check(RLDPC) matrices. The key idea of our construction is to achieve small mutual coherence of the matrices by confining the column weights of RLDPC matrices such that St RIP is satisfied. Besides, we prove that the constructed sensing matrices have the same scale of measurement numbers as the dense measurements. We also propose a data gathering method based on RLDPC matrix. Experimental results verify that the constructed sensing matrices have better reconstruction performance, compared to the Gaussian, Bernoulli, and CSLDPC matrices. And we also verify that the data gathering via RLDPC matrix can reduce energy consumption of WSNs. 展开更多
关键词 Data gathering regular low density parity check(RLDPC) matrix sensing matrix signal reconstruction wireless sensor networks(WSNs)
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Extraction of amplitude-preserving angle gathers based on vector wavefield reverse-time migration 被引量:2
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作者 Yang Jia-Jia Luan Xi-Wu +4 位作者 He Bing-Shou Fang Gang Pan Jun Ran Wei-Min Jiang Tao 《Applied Geophysics》 SCIE CSCD 2017年第4期492-504,620,共14页
Angle-domain common-image gathers (ADCIGs) transformed from the shot- domain common-offset gathers are input to migration velocity analysis (MVA) and prestack inversion. ADCIGs are non-illusion prestack inversion ... Angle-domain common-image gathers (ADCIGs) transformed from the shot- domain common-offset gathers are input to migration velocity analysis (MVA) and prestack inversion. ADCIGs are non-illusion prestack inversion gathers, and thus, accurate. We studied the extraction of elastic-wave ADCIGs based on amplitude-preserving elastic-wave reverse- time migration for calculating the incidence angle of P- and S-waves at each image point and for different source locations. The P- and S-waves share the same incident angle, namely the incident angle of the source P-waves. The angle of incidence of the source P-wavefield was the difference between the source P-wave propagation angle and the reflector dips. The propagation angle of the source P-waves was obtained from the polarization vector of the decomposed P-waves. The reflectors' normal direction angle was obtained using the complex wavenumber of the stacked reverse-time migration (RTM) images. The ADCIGs of P- and S-waves were obtained by rearranging the common-shot migration gathers based on the incident angle. We used a horizontally layered model, the graben medium model, and part of the Marmousi-II elastic model and field data to test the proposed algorithm. The results suggested that the proposed method can efficiently extract the P- and S-wave ADCIGs of the elastic-wave reverse-time migration, the P- and S-wave incident angle, and the angle-gather amplitude fidelity, and improve the MVA and prestack inversion. 展开更多
关键词 Elastic wave reverse-time migration vector wavefield angle-domain common- image gathers amplitude-preserving migration
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An optimization method for shale gas gathering system-Consideration of reliability enhancement under earthquake-related uncertainties 被引量:1
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作者 Yan Wu Zi-Yuan Cui +2 位作者 Hai Lin Yu-Fei Wang Xiao Feng 《Petroleum Science》 SCIE CAS CSCD 2022年第5期2431-2447,共17页
Shale gas gathering systems are of great importance in gas fields for the efficient and reliable transportation of gas.In traditional design methods,pipeline layouts are optimized only from an economic point of view,w... Shale gas gathering systems are of great importance in gas fields for the efficient and reliable transportation of gas.In traditional design methods,pipeline layouts are optimized only from an economic point of view,where reliability is evaluated after optimization.However,reliability can be enhanced by spare pipelines so that both economic and reliable aspects are evaluated simultaneously.Based on the idea of enhancing reliability,this research proposes a methodology for optimizing the pipeline layout problem including well clustering,stations site selecting,and piping.Different topology arrangements and spare pipelines are investigated to enhance the production efficiency and reliability of the pipeline network under earthquake-related uncertainties.Reliability evaluation is converted into an economic one so that the objective of this work is to minimize the total annual cost.To solve such a complex problem,genetic algorithm,K-means algorithm,Geo Steiner algorithm,Kruskal algorithm,linear programming and Monte Carlo simulations are combined.A real-world case study illustrates the effectiveness of the proposed methodology and shows a 36.53%reduction in the total annual cost compared with the initial scheme. 展开更多
关键词 Shale gas gathering system Network topology RELIABILITY UNCERTAINTY
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