期刊文献+
共找到20,032篇文章
< 1 2 250 >
每页显示 20 50 100
Chinese Translation of Japanese Quotation Sentences From the Perspective of Contextual Adaptation
1
作者 DING Pinyue 《Sino-US English Teaching》 2025年第2期48-52,共5页
Based on the contextual adaptation perspective of Verschueren’s Adaptation Theory,this paper explores the Chinese translation strategies of Japanese quotation sentences in the Yang translation of The Courage of One f... Based on the contextual adaptation perspective of Verschueren’s Adaptation Theory,this paper explores the Chinese translation strategies of Japanese quotation sentences in the Yang translation of The Courage of One from the perspectives of communicative context and linguistic context.The study finds that the Chinese translation of Japanese quotation sentences involves various strategies,including retaining direct quotations,converting direct quotations into statements,transforming direct quotations into attributive+noun forms,and alternating between direct and indirect quotations.This research provides a new perspective for the Chinese translation of Japanese quotation sentences and offers theoretical support for translation practices in cross-cultural communication. 展开更多
关键词 contextual adaptation communicative context direct quotation
在线阅读 下载PDF
基于Context量化和空间co-location模式的熵编码在基因组压缩中的应用
2
作者 陈慧 王丽珍 《中国科技信息》 2025年第13期135-137,共3页
1背景随着大数据和云计算等信息处理技术日趋应用广泛,熵编码日益普遍,它是以信息的概率分布特性作为编码的依据,是一种无失真的信源压缩和一种无损的压缩编码。然而在实际应用中,这些条件概率分布事先并不知道,需要通过估计得到。对条... 1背景随着大数据和云计算等信息处理技术日趋应用广泛,熵编码日益普遍,它是以信息的概率分布特性作为编码的依据,是一种无失真的信源压缩和一种无损的压缩编码。然而在实际应用中,这些条件概率分布事先并不知道,需要通过估计得到。对条件概率分布进行估计的过程称为Context建模。已有一些现成的基因组序列压缩工具可供使用,但这些工具并不针对特定基因组序列。因此,基于Context建模熵编码技术的生物基因组序列研究仍具有重要的理论意义。 展开更多
关键词 context建模 空间co-location模式 熵编码 基因组压缩
在线阅读 下载PDF
Transformation of the Teaching Mode for Higher Vocational Public Music Courses in the Context of Artificial Intelligence
3
作者 Libei He 《Journal of Contemporary Educational Research》 2025年第7期286-291,共6页
In recent years,the rapid integration of artificial intelligence(AI)with various industries has led to an intelligent transformation in people’s learning and working patterns.In the field of higher vocational public ... In recent years,the rapid integration of artificial intelligence(AI)with various industries has led to an intelligent transformation in people’s learning and working patterns.In the field of higher vocational public music course teaching,AI provides intelligent teaching tools and learning platforms,while offering students timely and scientific support and companionship,enabling them to complete learning tasks more efficiently.How to explore the transformation path of teaching modes for higher vocational public music courses in the AI context has become a key consideration for frontline teachers.Based on this,this paper first analyzes the significance of teaching higher vocational public music courses in the AI context,and then proposes feasible transformation paths for teaching modes in combination with course characteristics for reference. 展开更多
关键词 AI context Higher vocational education Public music courses Teaching mode TRANSFORMATION
在线阅读 下载PDF
Model adaptation via credible local context representation
4
作者 Song Tang Wenxin Su +2 位作者 Yan Yang Lijuan Chen Mao Ye 《CAAI Transactions on Intelligence Technology》 2025年第3期638-651,共14页
Conventional model transfer techniques,requiring the labelled source data,are not applicable in the privacy-protected medical fields.For the challenging scenarios,recent source data-free domain adaptation(SFDA)has bec... Conventional model transfer techniques,requiring the labelled source data,are not applicable in the privacy-protected medical fields.For the challenging scenarios,recent source data-free domain adaptation(SFDA)has become a mainstream solution but losing focus on the inter-sample class information.This paper proposes a new Credible Local Context Representation approach for SFDA.Our main idea is to exploit the credible local context for more discriminative representation.Specifically,we enhance the source model's discrimination by information regulating.To capture the context,a discovery method is developed that performs fixed steps walking in deep space and takes the credible features in this path as the context.In the epoch-wise adaptation,deep clustering-like training is conducted with two major updates.First,the context for all target data is constructed and then the context-fused pseudo-labels providing semantic guidance are generated.Second,for each target data,a weighting fusion on its context forms the anchored neighbourhood structure;thus,the deep clustering is switched from individual-based to coarse-grained.Also,a new regularisation building is developed on the anchored neighbourhood to drive the deep coarse-grained learning.Experiments on three benchmarks indicate that the proposed method can achieve stateof-the-art results. 展开更多
关键词 credible local context deep clustering domain adaptation machine learning model transfer self-supervised learning
在线阅读 下载PDF
FDCPNet:feature discrimination and context propagation network for 3D shape representation
5
作者 Weimin SHI Yuan XIONG +2 位作者 Qianwen WANG Han JIANG Zhong ZHOU 《虚拟现实与智能硬件(中英文)》 2025年第1期83-94,共12页
Background Three-dimensional(3D)shape representation using mesh data is essential in various applications,such as virtual reality and simulation technologies.Current methods for extracting features from mesh edges or ... Background Three-dimensional(3D)shape representation using mesh data is essential in various applications,such as virtual reality and simulation technologies.Current methods for extracting features from mesh edges or faces struggle with complex 3D models because edge-based approaches miss global contexts and face-based methods overlook variations in adjacent areas,which affects the overall precision.To address these issues,we propose the Feature Discrimination and Context Propagation Network(FDCPNet),which is a novel approach that synergistically integrates local and global features in mesh datasets.Methods FDCPNet is composed of two modules:(1)the Feature Discrimination Module,which employs an attention mechanism to enhance the identification of key local features,and(2)the Context Propagation Module,which enriches key local features by integrating global contextual information,thereby facilitating a more detailed and comprehensive representation of crucial areas within the mesh model.Results Experiments on popular datasets validated the effectiveness of FDCPNet,showing an improvement in the classification accuracy over the baseline MeshNet.Furthermore,even with reduced mesh face numbers and limited training data,FDCPNet achieved promising results,demonstrating its robustness in scenarios of variable complexity. 展开更多
关键词 3D shape representation Mesh model MeshNet Feature discrimination context propagation
在线阅读 下载PDF
Digital Context:Social Foundation and Technological Adaptation of Digital Rural Governance
6
作者 Ding Bo 《Contemporary Social Sciences》 2025年第6期116-134,共19页
Digital rural governance is a micro-level governance practice within the broader framework of building a Digital China.It involves the integration of digital technology into rural governance to drive the digital trans... Digital rural governance is a micro-level governance practice within the broader framework of building a Digital China.It involves the integration of digital technology into rural governance to drive the digital transformation of rural governance.In recognition of the varied development stages of digital rural governance,the concept of“digital context”provides an analytical lens for exploring the differences in practical models of digital rural governance.By examining the contextual characteristics and differential mechanisms of digital rural governance,this paper delves into its social foundation and technological adaptation.The research finds that the context of digital rural governance primarily encompasses three dimensions:contextual foundation,contextual logic,and contextual optimization.First,the contextual foundation of digital rural governance manifests as the social basis,comprising the social structure of villages,the type of village development,and the age structure of villagers,which constitute the social stratification forms underlying digital rural governance.Second,the contextual logic of digital rural governance focuses on the adaptation of digital technology to rural governance,promoting the adaptation of digital technology to the rural governance foundation,village governance scenarios,and villagers’digital capabilities.Third,the contextual optimization of digital rural governance emphasizes integrating digital technology with both administrative and livelihood-oriented governance affairs at the village level.This approach leverages the governance value and functional potential of digital technology to streamline digital governance processes and enhance digital governance capabilities.As a developmental direction for the transformation of rural governance,digital rural governance must not only highlight the governance advantages of digital technology but also prioritize the inherent context of rural governance.It aims to enhance the effectiveness of rural governance through digital technology and advance high-quality digital village development tailored to local conditions. 展开更多
关键词 digital village development digital rural governance digital context rural governance social foundation technological adaptation
在线阅读 下载PDF
Innovation and Practice of Corporate Financial Audit in the Context of Modern Education
7
作者 Jue Wang Xiaoji Ma 《Journal of Contemporary Educational Research》 2025年第9期195-201,共7页
With the development of modern educational concepts and technologies,corporate financial audit is facing unprecedented challenges and opportunities.This paper first analyzes the new characteristics of corporate financ... With the development of modern educational concepts and technologies,corporate financial audit is facing unprecedented challenges and opportunities.This paper first analyzes the new characteristics of corporate financial audit in the context of modern education,including the widespread application of digital audit tools,the diversification of audit content,and the increased requirements for audit efficiency.Then,it explores the innovative practices in corporate financial audit,such as the introduction of big data analysis technology,the construction of intelligent audit platforms,and the implementation of continuous audit.The paper also conducts an in-depth study on the impact of these innovative practices on the processes,quality,and risk management of corporate financial audit.Finally,it summarizes the effectiveness of the innovation and practice of corporate financial audit in the context of modern education,and looks forward to future development trends,providing references for theoretical research and practical operations in related fields. 展开更多
关键词 Modern education context Corporate financial audit Innovative practice Big data analysis Intelligent audit Continuous audit
在线阅读 下载PDF
Global Context Fusion Network for SAR Ship Detection
8
作者 Boya Zhang Yong Wang 《Journal of Beijing Institute of Technology》 2025年第6期577-589,共13页
Ship detection in synthetic aperture radar(SAR)image is crucial for marine surveillance and navigation.The application of detection network based on deep learning has achieved a promising result in SAR ship detection.... Ship detection in synthetic aperture radar(SAR)image is crucial for marine surveillance and navigation.The application of detection network based on deep learning has achieved a promising result in SAR ship detection.However,the existing networks encounters challenges due to the complex backgrounds,diverse scales and irregular distribution of ship targets.To address these issues,this article proposes a detection algorithm that integrates global context of the images(GCF-Net).First,we construct a global feature extraction module in the backbone network of GCF-Net,which encodes features along different spatial directions.Then,we incorporate bi-directional feature pyramid network(BiFPN)in the neck network to fuse the multi-scale features selectively.Finally,we design a convolution and transformer mixed(CTM)detection head to obtain contextual information of targets and concentrate network attention on the most informative regions of the images.Experimental results demonstrate that the proposed method achieves more accurate detection of ship targets in SAR images. 展开更多
关键词 synthetic aperture radar(SAR) ship detection global context fusion convolutional neural network feature extraction
在线阅读 下载PDF
CT-MFENet:Context Transformer and Multi-Scale Feature Extraction Network via Global-Local Features Fusion for Retinal Vessels Segmentation
9
作者 SHAO Dangguo YANG Yuanbiao +1 位作者 MA Lei YI Sanli 《Journal of Shanghai Jiaotong university(Science)》 2025年第4期668-682,共15页
Segmentation of the retinal vessels in the fundus is crucial for diagnosing ocular diseases.Retinal vessel images often suffer from category imbalance and large scale variations.This ultimately results in incomplete v... Segmentation of the retinal vessels in the fundus is crucial for diagnosing ocular diseases.Retinal vessel images often suffer from category imbalance and large scale variations.This ultimately results in incomplete vessel segmentation and poor continuity.In this study,we propose CT-MFENet to address the aforementioned issues.First,the use of context transformer(CT)allows for the integration of contextual feature information,which helps establish the connection between pixels and solve the problem of incomplete vessel continuity.Second,multi-scale dense residual networks are used instead of traditional CNN to address the issue of inadequate local feature extraction when the model encounters vessels at multiple scales.In the decoding stage,we introduce a local-global fusion module.It enhances the localization of vascular information and reduces the semantic gap between high-and low-level features.To address the class imbalance in retinal images,we propose a hybrid loss function that enhances the segmentation ability of the model for topological structures.We conducted experiments on the publicly available DRIVE,CHASEDB1,STARE,and IOSTAR datasets.The experimental results show that our CT-MFENet performs better than most existing methods,including the baseline U-Net. 展开更多
关键词 retinal vessel segmentation context transformer(CT) multi-scale dense residual hybrid loss function global-local fusion
原文传递
A novel method for ULS-TLS forest point cloud registration based on height context descriptor
10
作者 Xusong Dai Hanwen Qi +7 位作者 Xiaochen Wang Yaozhan Xu Qinghu Jiang Qingjun Zhang Xu Wang Jianchang Chen Guangzu Liu Xinlian Liang 《Forest Ecosystems》 2025年第6期1110-1126,共17页
Unmanned aerial vehicle laser scanning(ULS)and terrestrial laser scanning(TLS)systems are effective ways to capture forest structures from top and side views,respectively.The registration of TLS and ULS data is a prer... Unmanned aerial vehicle laser scanning(ULS)and terrestrial laser scanning(TLS)systems are effective ways to capture forest structures from top and side views,respectively.The registration of TLS and ULS data is a prerequisite for a comprehensive forest structure representation.Conventional registration methods based on geometric features(e.g.,points,lines,and planes)are likely to fail due to the irregular natural point distributions of forest point clouds.Currently,automatic registration methods for forest point clouds typically rely on tree attributes(such as tree position and stem diameter).However,these methods are often unsuitable for forests with diverse compositions,complex terrains,irregular tree layouts,and insufficient common trees.In this study,an automated method is proposed to register ULS and TLS forest point clouds using ground points as registration primitives,which operates independently of tree attribute extraction and is estimated to reduce processing time by over 50%.A new evaluation method for registration accuracy evaluation is proposed,where transformation parameters from each TLS scan to the ULS obtained by the proposed registration algorithm are used to derive transformation parameters between TLS scans,which are then compared to reference parameters obtained using artificial spherical targets.Conventional ULS-TLS registration evaluation methods mostly rely on the manual corresponding points selection that is subject to inherent subjective errors,or control points in both TLS and ULS data that are difficult to collect.The proposed method presents an objective and accurate solution for ULS-TLS registration accuracy evaluation that effectively eliminates these limitations.The proposed method was tested on 12 plots with diverse stem densities,tree species,and altitudes located in a mountain forest.A total of 124 TLS scans were successfully registered to ULS data.The registration accuracy was assessed using both the conventional evaluation method and the proposed new evaluation method,with average rotation errors of 2.03 and 2.06 mrad,and average translation errors of 7.63 and 6.51 cm,respectively.The registration accuracies demonstrate that the proposed algorithm effectively and accurately registers TLS to ULS point clouds. 展开更多
关键词 Unmanned aerial vehicle Light detection and ranging(LiDAR) Terrestrial laser scanning(TLS) Registration Ground points Height context descriptor
在线阅读 下载PDF
一种感知网Context存储策略
11
作者 秦怀峰 周兴社 《计算机工程》 EI CAS CSCD 北大核心 2006年第18期28-31,共4页
将contextaware理论融入感知网,有助于解决感知网的自适应问题。为此必须研究面向感知网的适当的context描述和存储机制。该文介绍了一种面向感知网的context存储策略――RBLS。RBLS在节点本地保存context,并根据节点持有的角色动态分... 将contextaware理论融入感知网,有助于解决感知网的自适应问题。为此必须研究面向感知网的适当的context描述和存储机制。该文介绍了一种面向感知网的context存储策略――RBLS。RBLS在节点本地保存context,并根据节点持有的角色动态分配其额外需要的context存储空间。“快照”被用来记录邻居节点的私有context。仿真结果显示RBLS是简单且能源有效的。 展开更多
关键词 context aware Sensornet context存储 角色
在线阅读 下载PDF
High-context and Low-context communication: A Case Study of A Chinese Refusal 被引量:1
12
作者 吴建晓 钱敏 《海外英语》 2013年第21期305-306,309,共3页
Edward Hall offers us an effective means of examining cultural similarities and differences,that is the classification of high-context and low-context culture.The paper attempts to analyze a case of a Chinese refusal ... Edward Hall offers us an effective means of examining cultural similarities and differences,that is the classification of high-context and low-context culture.The paper attempts to analyze a case of a Chinese refusal from the perspective of highcontext and low-context communication and explores the differences between the two types of communication. 展开更多
关键词 high-context LOW-context REFUSAL
在线阅读 下载PDF
Context概念与内涵及其在信息融合中的应用
13
作者 赵宗贵 李君灵 王珂 《指挥信息系统与技术》 2012年第2期11-16,86,共7页
阐述了Context的基本概念及其在人类认识世界中的作用,建立了Context敏感周期环,介绍了Context在知识获取中的作用。同时描述了人类认识阶段的划分及Context在各阶段的作用。最后阐述了信息融合与人类认识相对照的诸阶段中,Context的具... 阐述了Context的基本概念及其在人类认识世界中的作用,建立了Context敏感周期环,介绍了Context在知识获取中的作用。同时描述了人类认识阶段的划分及Context在各阶段的作用。最后阐述了信息融合与人类认识相对照的诸阶段中,Context的具体内涵和外延作用。 展开更多
关键词 context context敏感周期环 信息融合 基于知识的系统 态势估计
在线阅读 下载PDF
基于改进K均值的Context量化模型
14
作者 彭淑燕 刘思聪 《中国新通信》 2016年第6期14-16,共3页
为了提高图形编码系统压缩性能,可以通过使用Context模型来得到当前所要编码符号的概率。但是事实证明由于高阶Context模型很难在统计中有效收敛于信号的真实分布,结果使得编码效果降低,这就是所谓的"模型代价"问题。为了解... 为了提高图形编码系统压缩性能,可以通过使用Context模型来得到当前所要编码符号的概率。但是事实证明由于高阶Context模型很难在统计中有效收敛于信号的真实分布,结果使得编码效果降低,这就是所谓的"模型代价"问题。为了解决这一问题,一种有效的方法就是对高阶Context模型进行量化。由于Context量化问题与一般矢量量化问题相似,可以在设定合适的失真度量准则的条件下,使用聚类算法来实现Context量化。目前,K均值是使用比较广泛的一种聚类算法,但K均值算法必须具有确定的类数和选定的初始聚类中心。但在实际中,K均值往往难以准确界定,从而导致了聚类效果不佳。基于此,为了找到最佳的聚类数,本文提出采用聚类有效性函数来改进K均值聚类算法。 展开更多
关键词 context模型 context量化 聚类有效性 最佳聚类数目Kopt K均值
在线阅读 下载PDF
Mobile and Context-Aware GeoBI Applications: A Multilevel Model for Structuring and Sharing of Contextual Information
15
作者 Belko Abdoul Aziz Diallo Thierry Badard +1 位作者 Frédéric Hubert Sylvie Daniel 《Journal of Geographic Information System》 2012年第5期425-443,共19页
With the requirements for high performance results in the today’s mobile, global, highly competitive, and technology-based business world, business professionals have to get supported by convenient mobile decision su... With the requirements for high performance results in the today’s mobile, global, highly competitive, and technology-based business world, business professionals have to get supported by convenient mobile decision support systems (DSS). To give an improved support to mobile business professionals, it is necessary to go further than just allowing a simple remote access to a Business Intelligence platform. In this paper, the need for actual context-aware mobile Geospatial Business Intelligence (GeoBI) systems that can help capture, filter, organize and structure the user mobile context is exposed and justified. Furthermore, since capturing, structuring, and modeling mobile contextual information is still a research issue, a wide inventory of existing research work on context and mobile context is provided. Then, step by step, we methodologically identify relevant contextual information to capture for mobility purposes as well as for BI needs, organize them into context-dimensions, and build a hierarchical mobile GeoBI context model which (1) is geo-spatial-extended, (2) fits with human perception of mobility, (3) takes into account the local context interactions and information-sharing with remote contexts, and (4) matches with the usual hierarchical aggregated structure of BI data. 展开更多
关键词 context-AWARENESS Decision Support System (DSS) MOBILE GEOSPATIAL Business Intelligence (GeoBI) Decision-Making Relevant contextual Information context Dimensions context Modeling context SHARING context STRUCTURING BI Data
在线阅读 下载PDF
Adopting Context Mediation in Information Integration to Resolve Semantic Heterogeneity in Distributed Environment
16
作者 周建芳 徐海银 卢正鼎 《Journal of Southwest Jiaotong University(English Edition)》 2008年第4期359-365,共7页
Ontology-based semantic information integration resolve the schema-level heterogeneity and part of data level heterogeneity between distributed data sources. But it is ubiquitous that schema semantics of information i... Ontology-based semantic information integration resolve the schema-level heterogeneity and part of data level heterogeneity between distributed data sources. But it is ubiquitous that schema semantics of information is identical while the interpretation of it varies with different context, and ontology-based semantic information integration can not resolve this context heterogeneity. By introducing context representation and context mediation to ontology based information integration, the attribute-level context heterogeneity can be detected and reconciled automatically, and hence a complete solution for semantic heterogeneity is formed. Through a concrete example, the context representation and the process in which the attribute-level context heterogeneity is reconciled during query processing are presented. This resolution can make up the deficiency of schema mapping based semantic information integration. With the architecture proposed in this paper the semantic heterogeneity solution is adaptive and extensive. 展开更多
关键词 Semantic information integration Schema semantics Attribute-level context heterogeneity context conversion context mediation
在线阅读 下载PDF
Context and Teaching of EFL Reading
17
作者 李超慧 LI Tao 《海外英语》 2014年第23期126-127,共2页
Both linguistics and language teaching take language as their subject. Linguistics can provide language teaching with theories and language teaching can further prove the validity of linguistics. To some extent, lingu... Both linguistics and language teaching take language as their subject. Linguistics can provide language teaching with theories and language teaching can further prove the validity of linguistics. To some extent, linguistics is more theoretical while language teaching is more practical. Since linguistics is defined as the scientific study of language, it seems obvious that such a study would have direct relations to language teaching. This paper attempts to make an analysis of difference between Contextual theory of meaning and the teaching of EFL reading. 展开更多
关键词 context contextUAL THEORY EFL READING DISCOURSE an
在线阅读 下载PDF
海量层次信息的Focus+Context交互式可视化技术 被引量:7
18
作者 任磊 王威信 +3 位作者 滕东兴 马翠霞 戴国忠 王宏安 《软件学报》 EI CSCD 北大核心 2008年第11期3073-3082,共10页
综述了海量层次信息可视化与Focus+Context技术的相关工作,针对海量层次信息可视化的交互问题,在嵌套圆可视化技术的基础上提出了基于上下文感知的Focus+Context交互式可视化技术.首先,基于外切圆排列方法提出对圆心进行三角网格剖分的... 综述了海量层次信息可视化与Focus+Context技术的相关工作,针对海量层次信息可视化的交互问题,在嵌套圆可视化技术的基础上提出了基于上下文感知的Focus+Context交互式可视化技术.首先,基于外切圆排列方法提出对圆心进行三角网格剖分的方法,为变形计算建立上下文;然后,针对变形计算前后上下文一致性问题,在三角网格邻居跟踪方法的基础上,提出了用于同层兄弟节点上下文感知的外切圆变形排列方法,以及用于父子节点上下文感知的嵌套圆迭代排列方法.实验结果表明。上述方法在实现焦点突出的鱼眼视图的同时,能够有效地解决Focus+Context交互式可视化的上下文感知问题.上述方法应用于文件系统海量层次信息的交互式可视化问题,提供了交互式可视化工具. 展开更多
关键词 人机交互 用户界面 信息可视化 Focus+context 三角网格 上下文感知 文件系统
在线阅读 下载PDF
Reasoning about Context Information in Cloud Computing Environments
19
作者 Norihiro Kamide Yishui Zhu 《Journal of Software Engineering and Applications》 2012年第11期944-951,共8页
The notion of context provides flexibility and adaptation to cloud computing services. Location, time identity and activity of users are examples of primary context types. The motivation of this paper is to formalize ... The notion of context provides flexibility and adaptation to cloud computing services. Location, time identity and activity of users are examples of primary context types. The motivation of this paper is to formalize reasoning about context information in cloud computing environments. To formalize such context-aware reasoning, the logic LCM of context-mixture is introduced based on a Gentzen-type sequent calculus for an extended resource-sensitive logic. LCM has a specific inference rule called the context-mixture rule, which can naturally represent a mechanism for merging formulas with context information. Moreover, LCM has a specific modal operator called the sequence modal operator, which can suitably represent context information. The cut-elimination and embedding theorems for LCM are proved, and a fragment of LCM is shown to be decidable. These theoretical results are intended to provide a logical justification of context-aware cloud computing service models such as a flowable service model. 展开更多
关键词 context Information context-Mixture RULE Sequent CALCULUS Resource-Sensitive REASONING context-AWARE REASONING
在线阅读 下载PDF
基于Context模型的Shearlet变换地面微地震随机噪声压制 被引量:5
20
作者 李月 邵丹 +1 位作者 张超 马海涛 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2018年第12期4997-5006,共10页
地面微地震监测采集到的微地震信号通常能量微弱,信噪比低,如何提高微震数据的信噪比是数据处理的难题.Shearlet变换是一种新型的多尺度几何分析方法,具有敏感的方向性和较强的稀疏表示特性,能起到很好的随机噪声压制效果.由于地面微震... 地面微地震监测采集到的微地震信号通常能量微弱,信噪比低,如何提高微震数据的信噪比是数据处理的难题.Shearlet变换是一种新型的多尺度几何分析方法,具有敏感的方向性和较强的稀疏表示特性,能起到很好的随机噪声压制效果.由于地面微震数据的有效信号大多被淹没在噪声中,基于传统阈值的Shearlet变换(the traditional threshold-based Shearlet transform TST)只考虑到尺度或方向的阈值,在去噪过程中会过度扼制有效信号系数,造成有效信号能量损失.因而,本文建立Context模型,得到基于Context模型的Shearlet变换(the Context-model-based Shearlet transform CMST)方法,改进传统Shearlet阈值方法的不足.我们通过所建立的Context模型将能量相近的各方向系数划分为同一组,并分组估计阈值,分别处理各部分系数,达到微弱同相轴有效恢复的目的.通过TST及CMST的模拟实验与实际地面微震记录处理结果对比可知,本文方法在低信噪比条件下比对比方法更加有效地恢复地面微震数据的微弱信号,随机噪声压制效果明显,在-10dB条件下,提升信噪比18.3741dB. 展开更多
关键词 地面微地震监测 随机噪声 SHEARLET变换 context模型
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部