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Change of stream network connectivity and its impact on flood control 被引量:2
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作者 Yu-qin Gao Yun-ping Liu +2 位作者 Xiao-hua Lu Hao Luo Yue Liu 《Water Science and Engineering》 EI CAS CSCD 2020年第4期253-264,共12页
AbstUrbanization can alter the hydrogeomorphology of streams and rivers,change stream network structures,and reduce stream network connectivity,which leads to a decrease in the storage capacity of stream networks and ... AbstUrbanization can alter the hydrogeomorphology of streams and rivers,change stream network structures,and reduce stream network connectivity,which leads to a decrease in the storage capacity of stream networks and aggravates flood damage.Therefore,investigation of the ways in which stream network connectivity impacts flood storage capacity and flood control in urbanized watersheds can provide significant benefits.This study developed a framework to assess stream network connectivity and its impact on flood control.First,a few connectivity indices were adopted to assess longitudinal stream network connectivity.Afterward,the static and dynamic storage capacities of stream networks were evaluated using storage capacity indices and a one-dimensional hydrodynamic model.Finally,the impact of stream network connectivity change on flood control was assessed by investigating the changes in stream network connectivity and storage capacity.This framework was applied to the Qinhuai River Basin,China,where intensive urbanization has occurred in the last few decades.The results show that stream network storage capacity is affected by stream network connectivity.Increasing stream network connectivity enhances stream network storage capacity.©2020 Hohai University.Production and hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/). 展开更多
关键词 stream network connectivity Static storage capacity Dynamic storage capacity One-dimensional hydrodynamic model
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Modelling Uncertainty of Stream Networks Derived from Elevation Data Using Two Free Softwares: R and SAGA 被引量:1
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作者 Hammadi Achour Noamen Rebai +1 位作者 Jean Van Den Driessche Samir Bouaziz 《Journal of Geographic Information System》 2012年第2期153-160,共8页
Stream networks are considered important units in many environmental decision making processes. The extraction of streams using digital elevation models (DEMs) presents many advantages. However it is very sensitive to... Stream networks are considered important units in many environmental decision making processes. The extraction of streams using digital elevation models (DEMs) presents many advantages. However it is very sensitive to the uncertainty of the elevation datasets used. The main aim of this paper is to implement geostatistical simulations and assess the propagated uncertainty and map the error of location streams. First, point sampled elevations are used to fit a variogram model. Next two hundred DEM realizations are generated using conditional sequential Gaussian simulation;the stream network map is extracted for each of these realizations, and the collection of stream networks is analyzed to quantify the error propagation. At each grid cell, the probability of the occurrence of a stream and the propagated error are estimated. The more probable stream network are delineated and compared with the digital stream network derived from topographic map. The method is illustrated using a small dataset (8742 sampled elevations) for Anaguid Saharan platform. All computations are run in two free softwares: R and SAGA. R is used to fit variogram and to run sequential Gaussian simulation. SAGA is used to extract streams via RSAGA library. 展开更多
关键词 DEM stream network UNCERTAINTY Modeling R SAGA
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IDSSCNN-XgBoost:Improved Dual-Stream Shallow Convolutional Neural Network Based on Extreme Gradient Boosting Algorithm for Micro Expression Recognition
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作者 Adnan Ahmad Zhao Li +1 位作者 Irfan Tariq Zhengran He 《Computers, Materials & Continua》 SCIE EI 2025年第1期729-749,共21页
Micro-expressions(ME)recognition is a complex task that requires advanced techniques to extract informative features fromfacial expressions.Numerous deep neural networks(DNNs)with convolutional structures have been pr... Micro-expressions(ME)recognition is a complex task that requires advanced techniques to extract informative features fromfacial expressions.Numerous deep neural networks(DNNs)with convolutional structures have been proposed.However,unlike DNNs,shallow convolutional neural networks often outperform deeper models in mitigating overfitting,particularly with small datasets.Still,many of these methods rely on a single feature for recognition,resulting in an insufficient ability to extract highly effective features.To address this limitation,in this paper,an Improved Dual-stream Shallow Convolutional Neural Network based on an Extreme Gradient Boosting Algorithm(IDSSCNN-XgBoost)is introduced for ME Recognition.The proposed method utilizes a dual-stream architecture where motion vectors(temporal features)are extracted using Optical Flow TV-L1 and amplify subtle changes(spatial features)via EulerianVideoMagnification(EVM).These features are processed by IDSSCNN,with an attention mechanism applied to refine the extracted effective features.The outputs are then fused,concatenated,and classified using the XgBoost algorithm.This comprehensive approach significantly improves recognition accuracy by leveraging the strengths of both temporal and spatial information,supported by the robust classification power of XgBoost.The proposed method is evaluated on three publicly available ME databases named Chinese Academy of Sciences Micro-expression Database(CASMEII),Spontaneous Micro-Expression Database(SMICHS),and Spontaneous Actions and Micro-Movements(SAMM).Experimental results indicate that the proposed model can achieve outstanding results compared to recent models.The accuracy results are 79.01%,69.22%,and 68.99%on CASMEII,SMIC-HS,and SAMM,and the F1-score are 75.47%,68.91%,and 63.84%,respectively.The proposed method has the advantage of operational efficiency and less computational time. 展开更多
关键词 ME recognition dual stream shallow convolutional neural network euler video magnification TV-L1 XgBoost
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Error resilient concurrent video streaming over wireless mesh networks 被引量:2
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作者 CHUAH Chen-nee YOO Ben S.J. 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第5期684-695,共12页
In this paper, we propose a multi-source multi-path video streaming system for supporting high quality concurrent video-on-demand (VoD) services over wireless mesh networks (WMNs), and leverage forward error correctio... In this paper, we propose a multi-source multi-path video streaming system for supporting high quality concurrent video-on-demand (VoD) services over wireless mesh networks (WMNs), and leverage forward error correction to enhance the error resilience of the system. By taking wireless interference into consideration, we present a more realistic networking model to capture the characteristics of WMNs and then design a route selection scheme using a joint rate/interference-distortion optimiza- tion framework to help the system optimally select concurrent streaming paths. We mathematically formulate such a route selec- tion problem, and solve it heuristically using genetic algorithm. Simulation results demonstrate the effectiveness of our proposed scheme. 展开更多
关键词 Wireless MESH network CONCURRENT VIDEO streaming INTERFERENCE
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QoS Guaranteed Pre-Pushing Scheme in Peer-Assisted Streaming Network
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作者 LIN Fuhong LU Xing 《China Communications》 SCIE CSCD 2014年第A02期111-117,共7页
In peer-assisted streaming network, service provider needs to pre-pushing resources to some users for caching. This scheme can increase the resource availability. In traditional strategy, in order to guarantee the use... In peer-assisted streaming network, service provider needs to pre-pushing resources to some users for caching. This scheme can increase the resource availability. In traditional strategy, in order to guarantee the user's quality of service (QoS), the pre-pushing action can only start at the time point that the certain user has not used the computer for more than 20 minutes. If the user comes back, the pre-pushing action will be stopped. We claim that this is not an efficient scheme. In this paper, we propose a novel pre-pushing scheme to improve the pre-pushing efficiency, while meeting the user's QoS requirements. The basic idea is using the user's available bandwidth as much as possible in the condition of meeting the user's QoS requirements. Then we design an available bandwidth calculating strategy. The numerical simulation demonstrates that our proposed scheme outperforms the traditional one. 展开更多
关键词 peer-assisted streaming network downlink bandwidth pre-pushing available bandwidth
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A Real-Time TCP Stream Reassembly Mechanism in High-Speed Network 被引量:3
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作者 熊兵 陈晓苏 陈宁 《Journal of Southwest Jiaotong University(English Edition)》 2009年第3期185-191,共7页
With the continual growth of the variety and complexity of network crime means, the traditional packet feature matching cannot detect all kinds of intrusion behaviors completely. It is urgent to reassemble network str... With the continual growth of the variety and complexity of network crime means, the traditional packet feature matching cannot detect all kinds of intrusion behaviors completely. It is urgent to reassemble network stream to perform packet processing at a semantic level above the network layer. This paper presents an efficient TCP stream reassembly mechanism for real-time processing of high-speed network traffic. By analyzing the characteristics of network stream in high-speed network and TCP connection establishment process, several polices for designing the reassembly mechanism are built. Then, the reassembly implementation is elaborated in accordance with the policies. Finally, the reassembly mechanism is compared with the traditional reassembly mechanism by the network traffic captured in a typical gigabit gateway. Experiment results illustrate that the reassembly mechanism is efficient and can satisfy the real-time property requirement of traffic analysis system in high-speed network. 展开更多
关键词 TCP stream reassembly High-speed network Real-time property Reassembly policy
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Multimedia Streaming for Ad Hoc Wireless Mesh Networks Using Network Coding
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作者 Basil Saeed Chung-Horng Lung +1 位作者 Thomas Kunz Anand Srinivasan 《International Journal of Communications, Network and System Sciences》 2013年第5期204-220,共17页
Over the past years, we have witnessed an explosive growth in the use of multimedia applications such as audio and video streaming with mobile and static devices. Multimedia streaming applications need new approaches ... Over the past years, we have witnessed an explosive growth in the use of multimedia applications such as audio and video streaming with mobile and static devices. Multimedia streaming applications need new approaches to multimedia transmissions to meet the growing volume demand and quality expectations of multimedia traffic. This paper studies network coding which is a promising paradigm that has the potential to improve the performance of networks for multimedia streaming applications in terms of packet delivery ratio (PDR), latency and jitter. This paper examines several network coding protocols for ad hoc wireless mesh networks and compares their performance on multimedia streaming applications with optimized broadcast protocols, e.g., BCast, Simplified Multicast Forwarding (SMF), and Partial Dominant Pruning (PDP). The results show that the performance increases significantly with the Random Linear Network Coding (RLNC) scheme. 展开更多
关键词 Wireless Broadcast Multimedia streamING Audio streamING Video streamING network CODING Random Linear network CODING PDP SMF BCast
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Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks
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作者 SINGH Jatinder Pal GIROD Bernd 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第5期727-736,共10页
The support for multiple video streams in an ad-hoc wireless network requires appropriate routing and rate allocation measures ascertaining the set of links for transmitting each stream and the encoding rate of the vi... The support for multiple video streams in an ad-hoc wireless network requires appropriate routing and rate allocation measures ascertaining the set of links for transmitting each stream and the encoding rate of the video to be delivered over the chosen links. The routing and rate allocation procedures impact the sustained quality of each video stream measured as the mean squared error (MSE) distortion at the receiver, and the overall network congestion in terms of queuing delay per link. We study the trade-off between these two competing objectives in a convex optimization formulation, and discuss both centralized and dis- tributed solutions for joint routing and rate allocation for multiple streams. For each stream, the optimal allocated rate strikes a balance between the selfish motive of minimizing video distortion and the global good of minimizing network congestions, while the routes are chosen over the least-congested links in the network. In addition to detailed analysis, network simulation results using ns-2 are presented for studying the optimal choice of parameters and to confirm the effectiveness of the proposed measures. 展开更多
关键词 AD-HOC wireless networks VIDEO streaming Rate allocation MULTI-PATH ROUTING
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Author Gender Prediction in an Email Stream Using Neural Networks
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作者 William Deitrick Zachary Miller +3 位作者 Benjamin Valyou Brian Dickinson Timothy Munson Wei Hu 《Journal of Intelligent Learning Systems and Applications》 2012年第3期169-175,共7页
With the rapid growth of the Internet in recent years, the ability to analyze and identify its users has become increasingly important. Authorship analysis provides a means to glean information about the author of a d... With the rapid growth of the Internet in recent years, the ability to analyze and identify its users has become increasingly important. Authorship analysis provides a means to glean information about the author of a document originating from the internet or elsewhere, including but not limited to the author’s gender. There are well-known linguistic differences between the writing of men and women, and these differences can be effectively used to predict the gender of a document’s author. Capitalizing on these linguistic nuances, this study uses a set of stylometric features and a set of word count features to facilitate automatic gender discrimination on emails from the popular Enron email dataset. These features are used in conjunction with the Modified Balanced Winnow Neural Network proposed by Carvalho and Cohen, an improvement on the original Balanced Winnow created by Littlestone. Experiments with the Modified Balanced Winnow show that it is effectively able to discriminate gender using both stylometric and word count features, with the word count features providing superior results. 展开更多
关键词 1-Gram Word Counts Balanced WINNOW ENRON EMAIL GENDER PREDICTION Neural network stream Mining Stylometric Features
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Data Stream Subspace Clustering for Anomalous Network Packet Detection 被引量:1
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作者 Zachary Miller Wei Hu 《Journal of Information Security》 2012年第3期215-223,共9页
As the Internet offers increased connectivity between human beings, it has fallen prey to malicious users who exploit its resources to gain illegal access to critical information. In an effort to protect computer netw... As the Internet offers increased connectivity between human beings, it has fallen prey to malicious users who exploit its resources to gain illegal access to critical information. In an effort to protect computer networks from external attacks, two common types of Intrusion Detection Systems (IDSs) are often deployed. The first type is signature-based IDSs which can detect intrusions efficiently by scanning network packets and comparing them with human-generated signatures describing previously-observed attacks. The second type is anomaly-based IDSs able to detect new attacks through modeling normal network traffic without the need for a human expert. Despite this advantage, anomaly-based IDSs are limited by a high false-alarm rate and difficulty detecting network attacks attempting to blend in with normal traffic. In this study, we propose a StreamPreDeCon anomaly-based IDS. StreamPreDeCon is an extension of the preference subspace clustering algorithm PreDeCon designed to resolve some of the challenges associated with anomalous packet detection. Using network packets extracted from the first week of the DARPA '99 intrusion detection evaluation dataset combined with Generic Http, Shellcode and CLET attacks, our IDS achieved 94.4% sensitivity and 0.726% false positives in a best case scenario. To measure the overall effectiveness of the IDS, the average sensitivity and false positive rates were calculated for both the maximum sensitivity and the minimum false positive rate. With the maximum sensitivity, the IDS had 80% sensitivity and 9% false positives on average. The IDS also averaged 63% sensitivity with a 0.4% false positive rate when the minimal number of false positives is needed. These rates are an improvement on results found in a previous study as the sensitivity rate in general increased while the false positive rate decreased. 展开更多
关键词 ANOMALY DETECTION INTRUSION DETECTION System network Security PREFERENCE SUBSPACE Clustering stream Data Mining
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Dynamic multimedia stream adaptation and rate control for heterogeneous networks
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作者 SZWABE Andrzej SCHORR Andreas +1 位作者 HAUCK Franz J. KASSLER Andreas J. 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第z1期63-69,共7页
Dynamic adaptation of multimedia content is seen as an important feature of next generation networks and pervasive systems enabling terminals and applications to adapt to changes in e.g. context, access network, and a... Dynamic adaptation of multimedia content is seen as an important feature of next generation networks and pervasive systems enabling terminals and applications to adapt to changes in e.g. context, access network, and available Quality-of-Service(QoS) due to mobility of users, devices or sessions. We present the architecture of a multimedia stream adaptation service which enables communication between terminals having heterogeneous hardware and software capabilities and served by heterogeneous networks. The service runs on special content adaptation nodes which can be placed at any location within the network. The flexible structure of our architecture allows using a variety of different adaptation engines. A generic transcoding engine is used to change the codec of streams. An MPEG-21 Digital Item Adaptation (DIA) based transformation engine allows adjusting the data rate of scalable media streams. An intelligent decision-taking engine implements adaptive flow control which takes into account current network QoS parameters and congestion information. Measurements demonstrate the quality gains achieved through adaptive congestion control mechanisms under conditions typical for a heterogeneous network. 展开更多
关键词 stream adaptation QUALITY-OF-SERVICE (QoS) HETEROGENEOUS networks Rate control MPEG-21 DIA
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Sentiment Analysis on the Social Networks Using Stream Algorithms
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作者 Nathan Aston Timothy Munson +3 位作者 Jacob Liddle Garrett Hartshaw Dane Livingston Wei Hu 《Journal of Data Analysis and Information Processing》 2014年第2期60-66,共7页
The rising popularity of online social networks (OSNs), such as Twitter, Facebook, MySpace, and LinkedIn, in recent years has sparked great interest in sentiment analysis on their data. While many methods exist for id... The rising popularity of online social networks (OSNs), such as Twitter, Facebook, MySpace, and LinkedIn, in recent years has sparked great interest in sentiment analysis on their data. While many methods exist for identifying sentiment in OSNs such as communication pattern mining and classification based on emoticon and parts of speech, the majority of them utilize a suboptimal batch mode learning approach when analyzing a large amount of real time data. As an alternative we present a stream algorithm using Modified Balanced Winnow for sentiment analysis on OSNs. Tested on three real-world network datasets, the performance of our sentiment predictions is close to that of batch learning with the ability to detect important features dynamically for sentiment analysis in data streams. These top features reveal key words important to the analysis of sentiment. 展开更多
关键词 Modified BALANCED WINNOW SENTIMENT Analysis TWITTER Online Social networks Feature Selection Data streamS
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Coping with handover effects in video streaming over cellular networks
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作者 BOUAZIZI Imed HANNUKSELA Miska M RAUF Usama 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第z1期137-144,共8页
The 3rd generation partnership project (3GPP) has defined the protocols and codecs for implementing media streaming services over packet-switched 3G mobile networks. The specification is based on IETF RFCs on audio/vi... The 3rd generation partnership project (3GPP) has defined the protocols and codecs for implementing media streaming services over packet-switched 3G mobile networks. The specification is based on IETF RFCs on audio/video transport.It also adds new features to achieve better adaptation to the mobile network environment. In this paper, we propose an algorithm for handover detection and fast buffer refill that is based on the existing feedback and signaling mechanisms. The proposed algorithm refills the receiver buffer at a faster pace during a limited time frame after a hard handover is detected in order to achieve higher video quality. 展开更多
关键词 Video streaming 3GPP packet-switched streamING service HANDOVER detection HARD handover Fast BUFFER refill Mobile networks
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基于Spark Streaming的实时数据分析系统及其应用 被引量:30
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作者 韩德志 陈旭光 +2 位作者 雷雨馨 戴永涛 张肖 《计算机应用》 CSCD 北大核心 2017年第5期1263-1269,共7页
为了实现对实时网络数据流的快速分析,设计一种分布式实时数据流分析系统(DRDAS),能有效解决并发访问数据流的收集、存储和实时分析问题,为大数据环境的网络安全检测提供了一种有效的数据分析平台;根据Spark Streaming运行的原理设计一... 为了实现对实时网络数据流的快速分析,设计一种分布式实时数据流分析系统(DRDAS),能有效解决并发访问数据流的收集、存储和实时分析问题,为大数据环境的网络安全检测提供了一种有效的数据分析平台;根据Spark Streaming运行的原理设计一种动态采样的K-Means并行算法,与DRDAS结合能实时有效地检测大数据环境下的各种分布式拒绝服务(DDo S)攻击。实验结果显示:DRDAS具有好的可扩展性、容错性和实时处理能力,与动态采样的K-Means并行算法结合能实时地检测各种DDo S攻击,缩短了攻击的检测时间。 展开更多
关键词 SPARK streaming框架 分布式流处理 网络数据分析 分布式拒绝服务攻击
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HS-StreamCube:网络安全事件流实时多维分析系统 被引量:3
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作者 甘亮 李润恒 +1 位作者 贾焰 刘健 《计算机工程与科学》 CSCD 北大核心 2013年第3期72-79,共8页
大规模网络安全监控应用中,决策者应用数据流联机在线分析(Stream OLAP)技术对网络安全事件流建立流数据方(Stream Cube)进行实时分析,以了解当前网络安全状况并动态评估当前网络安全态势。由于内存容量有限,Stream Cube只关注当前时间... 大规模网络安全监控应用中,决策者应用数据流联机在线分析(Stream OLAP)技术对网络安全事件流建立流数据方(Stream Cube)进行实时分析,以了解当前网络安全状况并动态评估当前网络安全态势。由于内存容量有限,Stream Cube只关注当前时间窗口内的数据,而对于时间窗口外的过期数据则采用近似存储或简单地丢弃,所以不支持超出时间窗口范围的大时间窗口查询。针对以上缺陷,提出一种多维多层安全事件流实时分析框架HS-Stream Cube,采用内存和外存两层混合存储模式实现任意时间窗口的精确查询;然后根据数据流特点重点研究两层混合存储模式下HS-StreamCube的模型、构建、存储管理和查询等;最后通过实验验证该系统的可用性和高效性。 展开更多
关键词 流数据方 网络安全事件 混合存储 联机在线分析
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Two stream skeleton behavior recognition algorithm based on Motif-GCN 被引量:1
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作者 吴进 WANG Lei +1 位作者 FENG Haoran CHONG Gege 《High Technology Letters》 EI CAS 2023年第4期397-405,共9页
Compared with RGB videos and images,human bone data is less vulnerable to external factors and has stronger robustness.Therefore,behavior recognition methods based on skeletons are widely studied.Because graph convolu... Compared with RGB videos and images,human bone data is less vulnerable to external factors and has stronger robustness.Therefore,behavior recognition methods based on skeletons are widely studied.Because graph convolution network(GCN)can deal with the irregular topology data of hu-man skeletons very well,more and more researchers apply GCN to human behavior recognition.Tra-ditional graph convolution methods only consider the joints with physical connectivity or the same type when building the behavior recognition model based on human skeletons structure,which cannot capture higher-order information better.To solve this problem,Motif-GCN is used in this paper to ex-tract spatial features.The relationship between the joints with natural connection in the human body is encoded by the first Motif-GCN,and the possible relationship between the unconnected joints in the human skeleton is encoded by the second Motif-GCN.In this way,the relationship between non-physical joints can be strengthened.Then a two stream framework combining joint and bone informa-tion is used to capture more action information.Finally,experiments are conducted on two subdata-sets X-Sub and X-View of NTU-RGB+D,and the accuracy shown in Top-1 classification results is 89.5%and 95.4%respectively.The experimental results are 1.0%and 0.3%higher than those of the 2S-AGCN model respectively.The superiority of this method is also proved by the experimental results. 展开更多
关键词 skeleton behavior recognition Motif-GCN two stream network
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Stream Cast:基于对等网的流媒体分发系统 被引量:1
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作者 张钢 刘凌峰 刘春贵 《微处理机》 2005年第4期13-15,19,共4页
本文讨论了关于在互联网上向大量用户分发流媒体内容的问题。在传统的客户机服务器架构之上,考虑在客户端请求过多时可能出现的服务器过载情况。本文提出的StreamCast系统是一种基于对等网的技术,它能够减轻服务器的负载。本文比较详细... 本文讨论了关于在互联网上向大量用户分发流媒体内容的问题。在传统的客户机服务器架构之上,考虑在客户端请求过多时可能出现的服务器过载情况。本文提出的StreamCast系统是一种基于对等网的技术,它能够减轻服务器的负载。本文比较详细的讨论了所提出的解决方案,并且指出了一些有价值的研究问题。 展开更多
关键词 streamCast 对等网 流媒体 多播
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基于STREAMS机制的UNIX内核网络协议软件开发
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作者 毕军 吴建平 《计算机应用与软件》 CSCD 1999年第3期7-11,43,共6页
STREAMS机制是UNIX提供的一种开发工具。本文在对STREAMS机制进行介绍和分析的基础上,提出了基于STREAMS机制的开发UNIX内核网络协议软件的通用抽象模型。
关键词 streamS机制 网络协议软件 UNIX 软件开发
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StreamQCTree:一种流数据方压缩结构 被引量:1
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作者 甘亮 刘东红 +1 位作者 贾焰 韩伟红 《计算机工程与应用》 CSCD 北大核心 2011年第19期140-143,185,共5页
数据流管理系统计算聚集查询结果保存在内存中形成流数据方(StreamCube),提供快速、精确的在线OLAP查询。有限的内存空间需要一种有效的存储方法来存储更大时间窗口的流数据方。提出一种基于QC-Tree结构的流数据方StreamQCTree生成、裁... 数据流管理系统计算聚集查询结果保存在内存中形成流数据方(StreamCube),提供快速、精确的在线OLAP查询。有限的内存空间需要一种有效的存储方法来存储更大时间窗口的流数据方。提出一种基于QC-Tree结构的流数据方StreamQCTree生成、裁剪及查询方法。将QC-Tree结构中上界集划分为基本上界类和附加上界类;并分析附加上界类的成本计算模型;根据该模型在固定存储空间下,采用动态选择物化结点的方案选择物化部分附加上界类,使对StreamQCTree的平均查询响应时间最小。实验表明,StreamQCTree能够有效地访问数据方且获得较好的压缩效果。 展开更多
关键词 网络安全事件监控 streamQCTree 流数据方 数据压缩 联机分析处理 QC-Tree
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基于STREAMS机制的X.25广域网端对端通信技术
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作者 杨洪 庄毅 《计算机应用》 CSCD 1996年第2期20-22,共3页
本文介绍了STREAMS机制和X.25分组层协议PLP的一般原理,描述了如何利用NLI在分组级上实现X.25网络的端对端通信应用。
关键词 X.25协议 网络协议 广域网络 端对端通信
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