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基于OPC UA的双模网关设计
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作者 陈文炎 《无线通信技术》 2024年第2期7-12,共6页
随着工业物联网的快速发展,设备间的互联和数据交换变得越来越重要。OPC UA作为一种开放、跨平台的工业通信协议,已被广泛采用。本文设计了一款基于OPC UA协议的双模网关。OPC UA的SDK采用开源的open62541框架设计,为了实现可靠数据传... 随着工业物联网的快速发展,设备间的互联和数据交换变得越来越重要。OPC UA作为一种开放、跨平台的工业通信协议,已被广泛采用。本文设计了一款基于OPC UA协议的双模网关。OPC UA的SDK采用开源的open62541框架设计,为了实现可靠数据传输以及与其他基于TCP/IP的系统之间的互操作,同时又能提供实时高效的数据传输,本设计采用基于TCP/IP的C/S架构与基于UDP的Pub/Sub架构相结合的方式,实现不同类别的数据分流传输。为了实现用户程序和设备间的解耦,本设计采用JavaScript对象表示法(JSON)格式的配置文件定义设备信息,网关可通过解析该文件实现动态更新节点和设备信息。最后通过实验验证了所设计的双模网关具有较高的可靠性和实时性,适用于工业物联网中设备间数据交换的应用场景。 展开更多
关键词 OPC UA 工业网关 open62541 双模网 实时LINUX
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VoIP双模网关的研究与系统设计
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作者 夏海轮 丁炜 《电子技术应用》 北大核心 2006年第5期29-31,共3页
VoIP双模网关是一种同时连接VoIP网络和PSTN网络并能在两者之间互相切换的用户端网关设备,可广泛应用于小区和企业。详细阐述了双模网关的功能和工作原理,提出了一种基于H.323的支持四路话音的网关系统设计方案,包括硬件设计和软件设计... VoIP双模网关是一种同时连接VoIP网络和PSTN网络并能在两者之间互相切换的用户端网关设备,可广泛应用于小区和企业。详细阐述了双模网关的功能和工作原理,提出了一种基于H.323的支持四路话音的网关系统设计方案,包括硬件设计和软件设计方案,其中为了减少设备的物理端口数量,系统使用三相转接头。 展开更多
关键词 VOIP 双模网 用户端网关 H.323
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ZigBee-WiFi双模网关的研究与设计
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作者 王国华 郭其锐 黎智成 《中国新通信》 2017年第24期68-68,共1页
随着通信技术的发展,无线信息的抗干扰能力、纠错能力以及传递效果越来越强大,同时互联网技术的蓬勃发展也促使无线通信技术越来越便捷,越来越受到社会大众的重视与青睐,Wifi作为一种无需布线、覆盖范围广泛的通信技术为人们的生活提供... 随着通信技术的发展,无线信息的抗干扰能力、纠错能力以及传递效果越来越强大,同时互联网技术的蓬勃发展也促使无线通信技术越来越便捷,越来越受到社会大众的重视与青睐,Wifi作为一种无需布线、覆盖范围广泛的通信技术为人们的生活提供了巨大的便利,具有良好的应用前景。本文通过分析WIFI与Zig Bee协议,立足于嵌入式技术,设计研究出实现双模无线网关通信技术的方案,以促使双模网关能够更好的适应复杂环境。 展开更多
关键词 ZigBee-wifi 双模网 通信协调器
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基于2G的WCDMA网络规划
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作者 夏少波 梁科辉 《山东电大学报》 2006年第3期14-15,共2页
网络规划在很大程度上决定了网络的结构,对网络投资以及质量起着决定性作用,是将来网络发展的基础。WCDMA无线网络规划涵盖了无线资源规划、切换规划、容量规划、覆盖规划等众多方面,其中容量规划和覆盖规划是核心内容。
关键词 2G 3G WCDMA CDMA1X GSM CDMA 双模网
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Dual-scale multimedia dynamic synchronization model
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作者 李乃祥 《Journal of Chongqing University》 CAS 2009年第4期257-264,共8页
Multimedia synchronization is the key technology in application of distributed multimedia.Solution of synchronization conflicts insides and among streams as well as that of user interaction,synchronization granularity... Multimedia synchronization is the key technology in application of distributed multimedia.Solution of synchronization conflicts insides and among streams as well as that of user interaction,synchronization granularity refinement and synchronization precision improvement remain great challenges although great efforts have been invested by the academic circle.The construction method of a dual-scale dynamic synchronous model of multimedia presented in this article realizes multimedia synchronization on two sca... 展开更多
关键词 dual-scale MULTIMEDIA synchronous model Petri net AGENT
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Contention avoidance using dual-fuzzy assembly threshold algorithm in optical burst switching networks
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作者 杨九如 王钢 贾世楼 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第4期465-468,共4页
To avoid burst contention efficiently,on the basis of feedback-based source flow-rate control(SFC) strategy,a novel fuzzy-control-based assembly algorithm,called dual-fuzzy assembly threshold(DFAT),is proposed in an o... To avoid burst contention efficiently,on the basis of feedback-based source flow-rate control(SFC) strategy,a novel fuzzy-control-based assembly algorithm,called dual-fuzzy assembly threshold(DFAT),is proposed in an optical burst switching network.In our algorithm,according to the variations of burst assembly period and the interarrival of burst control packet,the traffic states of edge-switching nodes and core-switching nodes are first obtained.Then,the assembly threshold of bursts is set dynamically in order to operate the source traffic management from the information of traffic states.The performance of DFAT algorithm on burst loss probability is evaluated,and simulation results show that,compared with conventional assembly algorithms,the proposed scheme can constrain the birth of burst contention efficiently,when being a heavy load state of network. 展开更多
关键词 optical burst switching contention avoidance burst assembly dual feedback mechanism
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Empirical Study of "Double Threshold" Modified Model on New Product Diffusion
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作者 LIU Dan SHENG Qiran XIN Zhanhong CAO Jiantong 《China Communications》 SCIE CSCD 2014年第12期44-53,共10页
The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified mode... The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters. 展开更多
关键词 innovation diffusion threshold innovation model empirical study social network
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Model and algorithm of optimizing alternate traffic restriction scheme in urban traffic network 被引量:1
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作者 徐光明 史峰 +1 位作者 刘冰 黄合来 《Journal of Central South University》 SCIE EI CAS 2014年第12期4742-4752,共11页
An optimization model and its solution algorithm for alternate traffic restriction(ATR) schemes were introduced in terms of both the restriction districts and the proportion of restricted automobiles. A bi-level progr... An optimization model and its solution algorithm for alternate traffic restriction(ATR) schemes were introduced in terms of both the restriction districts and the proportion of restricted automobiles. A bi-level programming model was proposed to model the ATR scheme optimization problem by aiming at consumer surplus maximization and overload flow minimization at the upper-level model. At the lower-level model, elastic demand, mode choice and multi-class user equilibrium assignment were synthetically optimized. A genetic algorithm involving prolonging codes was constructed, demonstrating high computing efficiency in that it dynamically includes newly-appearing overload links in the codes so as to reduce the subsequent searching range. Moreover,practical processing approaches were suggested, which may improve the operability of the model-based solutions. 展开更多
关键词 urban traffic congestion alternate traffic restriction equilibrium analysis bi-level programming model
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A multi-attention RNN-based relation linking approach for question answering over knowledge base 被引量:1
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作者 Li Huiying Zhao Man Yu Wenqi 《Journal of Southeast University(English Edition)》 EI CAS 2020年第4期385-392,共8页
Aiming at the relation linking task for question answering over knowledge base,especially the multi relation linking task for complex questions,a relation linking approach based on the multi-attention recurrent neural... Aiming at the relation linking task for question answering over knowledge base,especially the multi relation linking task for complex questions,a relation linking approach based on the multi-attention recurrent neural network(RNN)model is proposed,which works for both simple and complex questions.First,the vector representations of questions are learned by the bidirectional long short-term memory(Bi-LSTM)model at the word and character levels,and named entities in questions are labeled by the conditional random field(CRF)model.Candidate entities are generated based on a dictionary,the disambiguation of candidate entities is realized based on predefined rules,and named entities mentioned in questions are linked to entities in knowledge base.Next,questions are classified into simple or complex questions by the machine learning method.Starting from the identified entities,for simple questions,one-hop relations are collected in the knowledge base as candidate relations;for complex questions,two-hop relations are collected as candidates.Finally,the multi-attention Bi-LSTM model is used to encode questions and candidate relations,compare their similarity,and return the candidate relation with the highest similarity as the result of relation linking.It is worth noting that the Bi-LSTM model with one attentions is adopted for simple questions,and the Bi-LSTM model with two attentions is adopted for complex questions.The experimental results show that,based on the effective entity linking method,the Bi-LSTM model with the attention mechanism improves the relation linking effectiveness of both simple and complex questions,which outperforms the existing relation linking methods based on graph algorithm or linguistics understanding. 展开更多
关键词 question answering over knowledge base(KBQA) entity linking relation linking multi-attention bidirectional long short-term memory(Bi-LSTM) large-scale complex question answering dataset(LC-QuAD)
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