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Accelerated Particle Swarm Optimization Algorithm for Efficient Cluster Head Selection in WSN
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作者 Imtiaz Ahmad Tariq Hussain +3 位作者 Babar Shah Altaf Hussain Iqtidar Ali Farman Ali 《Computers, Materials & Continua》 SCIE EI 2024年第6期3585-3629,共45页
Numerous wireless networks have emerged that can be used for short communication ranges where the infrastructure-based networks may fail because of their installation and cost.One of them is a sensor network with embe... Numerous wireless networks have emerged that can be used for short communication ranges where the infrastructure-based networks may fail because of their installation and cost.One of them is a sensor network with embedded sensors working as the primary nodes,termed Wireless Sensor Networks(WSNs),in which numerous sensors are connected to at least one Base Station(BS).These sensors gather information from the environment and transmit it to a BS or gathering location.WSNs have several challenges,including throughput,energy usage,and network lifetime concerns.Different strategies have been applied to get over these restrictions.Clustering may,therefore,be thought of as the best way to solve such issues.Consequently,it is crucial to analyze effective Cluster Head(CH)selection to maximize efficiency throughput,extend the network lifetime,and minimize energy consumption.This paper proposed an Accelerated Particle Swarm Optimization(APSO)algorithm based on the Low Energy Adaptive Clustering Hierarchy(LEACH),Neighboring Based Energy Efficient Routing(NBEER),Cooperative Energy Efficient Routing(CEER),and Cooperative Relay Neighboring Based Energy Efficient Routing(CR-NBEER)techniques.With the help of APSO in the implementation of the WSN,the main methodology of this article has taken place.The simulation findings in this study demonstrated that the suggested approach uses less energy,with respective energy consumption ranges of 0.1441 to 0.013 for 5 CH,1.003 to 0.0521 for 10 CH,and 0.1734 to 0.0911 for 15 CH.The sending packets ratio was also raised for all three CH selection scenarios,increasing from 659 to 1730.The number of dead nodes likewise dropped for the given combination,falling between 71 and 66.The network lifetime was deemed to have risen based on the results found.A hybrid with a few valuable parameters can further improve the suggested APSO-based protocol.Similar to underwater,WSN can make use of the proposed protocol.The overall results have been evaluated and compared with the existing approaches of sensor networks. 展开更多
关键词 Wireless sensor network cluster head selection low energy adaptive clustering hierarchy accelerated particle swarm optimization
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Marker-assisted selection to pyramid Fusarium head blight resistance loci Fhb1 and Fhb2 in the high-quality soft wheat cultivar Yangmai 15
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作者 HU Wen-jing FU Lu-ping +3 位作者 GAO De-rong LI Dong-sheng LIAO Sen LU Cheng-bin 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第2期360-370,共11页
Fusarium head blight(FHB)is one of the most detrimental wheat diseases which greatly decreases the yield and grain quality,especially in the middle and lower reaches of the Yangtze River of China.Fhb1 and Fhb2 are two... Fusarium head blight(FHB)is one of the most detrimental wheat diseases which greatly decreases the yield and grain quality,especially in the middle and lower reaches of the Yangtze River of China.Fhb1 and Fhb2 are two major resistance loci against Fusarium graminearum.Yangmai 15(YM15)is one of the most popular varieties in the middle and lower reaches of the Yangtze River,and it has good weak gluten characters but poor resistance to FHB.Here we used Fhb1 and Fhb2 to improve the FHB resistance of YM15 by a molecular marker-assisted selection(MAS)backcrossing strategy.The selection of agronomic traits was performed for each generation.We successfully selected seven introgressed lines which carry homozygous Fhb1 and Fhb2 with significantly higher FHB resistance than the recurrent parent YM15.Three of the introgressed lines had agronomic and quality characters that were similar to YM15.This study demonstrates that the pyramiding of Fhb1 and Fhb2 could significantly improve the FHB resistance in wheat using the MAS approach. 展开更多
关键词 Fusarium head blight marker-assisted selection Fhb1 Fhb2 resistance breeding WHEAT
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Cluster Head Selection Algorithm for UAV Assisted Clustered IoT Network Utilizing Blockchain 被引量:2
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作者 LIN Xinhua ZHANG Jing LI Qiang 《ZTE Communications》 2021年第1期30-38,共9页
To guarantee the security of Internet of Things(IoT)devices,the blockchain tech⁃nology is often applied to clustered IoT networks.However,cluster heads(CHs)need to un⁃dertake additional control tasks.For battery-power... To guarantee the security of Internet of Things(IoT)devices,the blockchain tech⁃nology is often applied to clustered IoT networks.However,cluster heads(CHs)need to un⁃dertake additional control tasks.For battery-powered IoT devices,the conventional CH se⁃lection algorithm is limited.Based on the above problem,an unmanned aerial vehicle(UAV)network assisted clustered IoT system is proposed,and a corresponding UAV CH se⁃lection algorithm is designed.In this scheme,UAVs are selected as CHs to serve IoT clus⁃ters.The proposed CH selection algorithm considers the maximal transmit power,residual energy and distance information of UAVs,which can greatly extend the working life of IoT clusters.Through Monte Carlo simulation,the key performance indexes of the system,in⁃cluding energy consumption,average secrecy rate and the maximal number of data packets received by the base station(BS),are evaluated.The simulation results show that the pro⁃posed algorithm has great advantages compared with the existing CH selection algorithms. 展开更多
关键词 cluster head selection unmanned aerial vehicle blockchain IOT average secrecy rate
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Stochastic Ranking Improved Teaching-Learning and Adaptive Grasshopper Optimization Algorithm-Based Clustering Scheme for Augmenting Network Lifetime in WSNs
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作者 N Tamilarasan SB Lenin +1 位作者 P Mukunthan NC Sendhilkumar 《China Communications》 SCIE CSCD 2024年第9期159-178,共20页
In Wireless Sensor Networks(WSNs),Clustering process is widely utilized for increasing the lifespan with sustained energy stability during data transmission.Several clustering protocols were devised for extending netw... In Wireless Sensor Networks(WSNs),Clustering process is widely utilized for increasing the lifespan with sustained energy stability during data transmission.Several clustering protocols were devised for extending network lifetime,but most of them failed in handling the problem of fixed clustering,static rounds,and inadequate Cluster Head(CH)selection criteria which consumes more energy.In this paper,Stochastic Ranking Improved Teaching-Learning and Adaptive Grasshopper Optimization Algorithm(SRITL-AGOA)-based Clustering Scheme for energy stabilization and extending network lifespan.This SRITL-AGOA selected CH depending on the weightage of factors such as node mobility degree,neighbour's density distance to sink,single-hop or multihop communication and Residual Energy(RE)that directly influences the energy consumption of sensor nodes.In specific,Grasshopper Optimization Algorithm(GOA)is improved through tangent-based nonlinear strategy for enhancing the ability of global optimization.On the other hand,stochastic ranking and violation constraint handling strategies are embedded into Teaching-Learning-based Optimization Algorithm(TLOA)for improving its exploitation tendencies.Then,SR and VCH improved TLOA is embedded into the exploitation phase of AGOA for selecting better CH by maintaining better balance amid exploration and exploitation.Simulation results confirmed that the proposed SRITL-AGOA improved throughput by 21.86%,network stability by 18.94%,load balancing by 16.14%with minimized energy depletion by19.21%,compared to the competitive CH selection approaches. 展开更多
关键词 Adaptive Grasshopper Optimization Algorithm(AGOA) Cluster head(ch) network lifetime Teaching-Learning-based Optimization Algorithm(TLOA) Wireless Sensor Networks(WSNs)
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Optimization of Head Cluster Selection in WSN by Human-Based Optimization Techniques
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作者 Hajer Faris Musaria Karim Mahmood +1 位作者 Osama Ahmad Alomari Ashraf Elnagar 《Computers, Materials & Continua》 SCIE EI 2022年第9期5643-5661,共19页
Wireless sensor networks(WSNs)are characterized by their ability to monitor physical or chemical phenomena in a static or dynamic location by collecting data,and transmit it in a collaborative manner to one or more pr... Wireless sensor networks(WSNs)are characterized by their ability to monitor physical or chemical phenomena in a static or dynamic location by collecting data,and transmit it in a collaborative manner to one or more processing centers wirelessly using a routing protocol.Energy dissipation is one of the most challenging issues due to the limited power supply at the sensor node.All routing protocols are large consumers of energy,as they represent the main source of energy cost through data exchange operation.Clusterbased hierarchical routing algorithms are known for their good performance in energy conservation during active data exchange in WSNs.The most common of this type of protocol is the Low-Energy Adaptive Clustering Hierarchy(LEACH),which suffers from the problem of the pseudo-random selection of cluster head resulting in large power dissipation.This critical issue can be addressed by using an optimization algorithm to improve the LEACH cluster heads selection process,thus increasing the network lifespan.This paper proposes the LEACH-CHIO,a centralized cluster-based energyaware protocol based on the Coronavirus Herd Immunity Optimizer(CHIO)algorithm.CHIO is a newly emerging human-based optimization algorithm that is expected to achieve significant improvement in the LEACH cluster heads selection process.LEACH-CHIO is implemented and its performance is verified by simulating different wireless sensor network scenarios,which consist of a variable number of nodes ranging from 20 to 100.To evaluate the algorithm performances,three evaluation indicators have been examined,namely,power consumption,number of live nodes,and number of incoming packets.The simulation results demonstrated the superiority of the proposed protocol over basic LEACH protocol for the three indicators. 展开更多
关键词 WSN LEAch coronavirus herd immunity optimizer cluster head selection
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A journey to understand wheat Fusarium head blight resistance in the Chinese wheat landrace Wangshuibai 被引量:30
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作者 Haiyan Jia Jiyang Zhou +9 位作者 Shulin Xue Guoqiang Li Haisheng Yan Congfu Ran Yiduo Zhang Jinxing Shi Li Jia Xin Wang Jing Luo Zhengqiang Ma 《The Crop Journal》 SCIE CAS CSCD 2018年第1期48-59,共12页
Fusarium head blight(FHB) or scab caused by Fusarium graminearum is a major threat to wheat production in China as well as in the world. To combat this disease, multiple efforts have been carried out internationally. ... Fusarium head blight(FHB) or scab caused by Fusarium graminearum is a major threat to wheat production in China as well as in the world. To combat this disease, multiple efforts have been carried out internationally. In this article, we review our long-time effort in identifying the resistance genes and dissecting the resistance mechanisms by both forward and reverse genetics approaches in the last two decades. We present recent progress in resistance QTL identification, candidate functional gene discovery, marker-assisted improvement of FHB resistant varieties, and findings in investigating association of signal molecules, such as Ca^(++),SA, JA, and ET, with FHB response, with the assistance from rapidly growing genomics platforms. The information will be helpful for designing novel and efficient approaches to curb FHB. 展开更多
关键词 FUSARIUM head blight QTL Gene discovery Marker-assisted selection TRITICUM AESTIVUM
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Type II Fuzzy Logic Based Cluster Head Selection for Wireless Sensor Network 被引量:2
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作者 J.Jean Justus M.Thirunavukkarasan +3 位作者 K.Dhayalini G.Visalaxi Adel Khelifi Mohamed Elhoseny 《Computers, Materials & Continua》 SCIE EI 2022年第1期801-816,共16页
Wireless Sensor Network(WSN)forms an essential part of IoT.It is embedded in the target environment to observe the physical parameters based on the type of application.Sensor nodes inWSN are constrained by different f... Wireless Sensor Network(WSN)forms an essential part of IoT.It is embedded in the target environment to observe the physical parameters based on the type of application.Sensor nodes inWSN are constrained by different features such as memory,bandwidth,energy,and its processing capabilities.In WSN,data transmission process consumes the maximum amount of energy than sensing and processing of the sensors.So,diverse clustering and data aggregation techniques are designed to achieve excellent energy efficiency in WSN.In this view,the current research article presents a novel Type II Fuzzy Logic-based Cluster Head selection with Low Complexity Data Aggregation(T2FLCH-LCDA)technique for WSN.The presented model involves a two-stage process such as clustering and data aggregation.Initially,three input parameters such as residual energy,distance to Base Station(BS),and node centrality are used in T2FLCH technique for CH selection and cluster construction.Besides,the LCDA technique which follows Dictionary Based Encoding(DBE)process is used to perform the data aggregation at CHs.Finally,the aggregated data is transmitted to the BS where it achieves energy efficiency.The experimental validation of the T2FLCH-LCDAtechnique was executed under three different scenarios based on the position of BS.The experimental results revealed that the T2FLCH-LCDA technique achieved maximum energy efficiency,lifetime,Compression Ratio(CR),and power saving than the compared methods. 展开更多
关键词 CLUSTERING data aggregation energy consumption cluster head selection wireless sensor networks
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基于簇头节点能量均衡选择的LEACH优化算法 被引量:1
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作者 吴英浩 石元博 黄越洋 《辽宁石油化工大学学报》 CAS 2023年第6期82-88,共7页
针对无线传感网络中LEACH协议在进行簇头节点选择时能量消耗过快导致的生存周期短、数据吞吐量低等问题,提出了一种基于簇头节点能量均衡选择的LEACH优化算法。该算法选取WSNs中剩余能量高的普通节点作为簇头节点,同时考虑普通节点与簇... 针对无线传感网络中LEACH协议在进行簇头节点选择时能量消耗过快导致的生存周期短、数据吞吐量低等问题,提出了一种基于簇头节点能量均衡选择的LEACH优化算法。该算法选取WSNs中剩余能量高的普通节点作为簇头节点,同时考虑普通节点与簇头节点、簇头节点与基站之间的距离,以及所有节点的剩余能量和平均能量等因素来选择通信方式和传输路径。通过MATLAB工具,对提出的算法进行了仿真实验。结果表明,在100 m×100 m的小面积监测区域和200 m×200 m的大面积监测区域内,与LEACH、DEEC、IMP-LEACH算法相比,该算法降低了WSNs中节点的能量消耗,延长了生存周期,同时提高了数据吞吐量。 展开更多
关键词 无线传感网络 LEAch协议 簇头节点选择 能量均衡 网络生存周期
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AN EFFICIENT UE CLUSTER HEAD SELECTION ALGORITHM IN WIRELESS SENSOR NETWORKS AND CELLULAR NETWORKS
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作者 Shan Lianhai Ouyang Yuling +2 位作者 Yuan Zhi Fang Weidong Hu Honglin 《Journal of Electronics(China)》 2013年第1期57-65,共9页
Wireless Sensor Networks (WSNs) have been applied in many different areas. Energy efficient algorithms and protocols have become one of the most challenging issues for WSN. Many researchers focused on developing energ... Wireless Sensor Networks (WSNs) have been applied in many different areas. Energy efficient algorithms and protocols have become one of the most challenging issues for WSN. Many researchers focused on developing energy efficient clustering algorithms for WSN, but less research has been concerned in the mobile User Equipment (UE) acting as a Cluster Head (CH) for data transmission between cellular networks and WSNs. In this paper, we propose a cellular-assisted UE CH selection algorithm for the WSN, which considers several parameters to choose the optimal UE gateway CH. We analyze the energy cost of data transmission from a sensor node to the next node or gateway and calculate the whole system energy cost for a WSN. Simulation results show that better system performance, in terms of system energy cost and WSNs life time, can be achieved by using interactive optimization with cellular networks. 展开更多
关键词 Wireless Sensor Networks (WSNs) Cluster head ch Gateway ch level Energy cost
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A LEACH-Head Expected Frequency Appraisal Algorithm for Water-Environment Monitoring Networks
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作者 Chenmin Li Guoping Tan +2 位作者 Jingyu Wu Zhen Zhang Lizhong Xu 《International Journal of Communications, Network and System Sciences》 2011年第9期562-567,共6页
Water-environment monitoring network (WMN) is a wireless sensor network based real-time system, which collects, transmits, analyzes and processes water-environment parameters in large area. Both cluster selection mech... Water-environment monitoring network (WMN) is a wireless sensor network based real-time system, which collects, transmits, analyzes and processes water-environment parameters in large area. Both cluster selection mechanisms and energy saving strategies play an important role on designing network routing protocols for the WMN. Since those existing routing algorithms can not be used directly in the WMN, we thus propose an improved version of LEACH, a LEACH-Head Expected Frequency Appraisal (LEACH-HEFA) algorithm, for the WMN in this paper. Simulation results show that the LEACH-HEFA can balance the energy consumption of nodes, rationalize the clustering process and prolong the network lifetime significantly in the WMN. It indicates that the LEACH-HEFA is suitable to the WMN. 展开更多
关键词 WSN LEAch Protocol Cluster-head selection Water-Environment Monitoring
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Study on Breeding Practices and Reproductive Performance of Black-Head Somali Sheep under Traditional Management System: The Case of Awbarre District, Eastern Ethiopia
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作者 Abdi Abdilahi Kawnin Abdimahad +1 位作者 Abdulahi Mahamed Abdimawlid Ali 《Open Journal of Animal Sciences》 CAS 2023年第1期20-33,共14页
The study was conducted in the Awbarre district of the Fafen zone of the Somali regional state of Ethiopia. The objective of the study was to assess the breeding practices and reproductive performance of Black-head So... The study was conducted in the Awbarre district of the Fafen zone of the Somali regional state of Ethiopia. The objective of the study was to assess the breeding practices and reproductive performance of Black-head Somali sheep under a traditional management system. Purposive and simple random sampling techniques were used to select targeted kebeles and households, respectively. A total of 120 households were selected from four kebeles, each of 30 households, based on the production system and sheep population. Semi-structured questionnaires, group discussions, key informants interviews and field observations were used to generate the required data. The primary purpose of keeping sheep was for income generation, followed by saving as a future asset. The majority (89.2%) of the respondents separated male and female animals during herding. The selection criteria for breeding rams were appearance, growth, pedigree, and color while for breeding ewes were appearance, adaptability, pedigree, color, and lamb growth. The overall weaning age of Black-head Somali sheep in the study area was 3.7 months for both males & females. The castration of male sheep was common for the purpose of fattening, fattening with breeding control and breeding control as well. The castration is mainly performed during the summer and autumn and the methods of castration were both traditional and modern methods, the traditional castration method being the most important one in pastoral areas. The age of sexual maturity was 7.64 months for rams and 8.97 months for ewe’s male and female lambs in the pastoral area and 8.42 & 8.38 for rams & ewes in agro-pastoral and overall lambing interval was 11 months. On average, the ewe of Black-head Somali sheep in pastoral & agro-pastoral could produce 9.49 & 9.57 lambs, respectively in their lifetime. As the pastoralists and agro-pastoralists indicated the source of the breeding ram was their own, so the exchange of breeding ram is recommended to minimize the risk of inbreeding and further studies of on-farm performance investigation would be necessary to be carried out so as to understand the uniqueness of the breed better. 展开更多
关键词 Black-head Somali Sheep Breeding Practice Reproductive Performance selection Criteria
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基于SHAP重要性排序和时空双流的多风场超短期功率预测
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作者 付波 李昊 +3 位作者 权轶 李超顺 赵熙临 杨远程 《重庆理工大学学报(自然科学)》 CAS 北大核心 2024年第5期249-258,共10页
针对多风场风功率预测中时空特征提取不充分的问题,提出一种基于空间、时间双流特征提取的功率预测方法。采用沙普利加性解释(SHAP)方法分析原始高维数值天气预报(NWP)中各变量的重要性,选择贡献度高的变量子集作为预测模型输入,降低模... 针对多风场风功率预测中时空特征提取不充分的问题,提出一种基于空间、时间双流特征提取的功率预测方法。采用沙普利加性解释(SHAP)方法分析原始高维数值天气预报(NWP)中各变量的重要性,选择贡献度高的变量子集作为预测模型输入,降低模型复杂度。构建基于自适应动态邻接矩阵的改进图注意力网络(IGAT)提取多风场的动态空间特征;同时将多头注意力机制(MHA)与时间卷积网络(TCN)结合,加强关键时序特征的学习。使用前馈神经网络输出多风场功率预测结果。以西北某十风场的数据进行案例研究,结果表明所提模型的预测效果优于其他模型。 展开更多
关键词 多风场功率预测 变量选择 图注意力网络 多头注意力机制 时间卷积网络
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边缘计算中支持分簇编排的应用缓存方法研究
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作者 张文柱 邵正源 余静华 《小型微型计算机系统》 CSCD 北大核心 2024年第5期1209-1217,共9页
移动边缘计算通过在距离终端更近的位置提供计算存储服务来提供更优的任务处理表现.为减少系统通信链路压力,进一步优化任务处理时延和能耗,本文首先提出了一种支持位置更新的分布式分簇编排策略,对通信区域进行分簇和簇头选取,簇头作... 移动边缘计算通过在距离终端更近的位置提供计算存储服务来提供更优的任务处理表现.为减少系统通信链路压力,进一步优化任务处理时延和能耗,本文首先提出了一种支持位置更新的分布式分簇编排策略,对通信区域进行分簇和簇头选取,簇头作为编排节点进行簇内管理,当有卸载任务时寻找最佳执行设备进行处理;然后基于Docker容器提出应用程序协作缓存算法,通过在存储资源丰富的设备中提前部署高频拉取的应用程序来降低任务部署延迟,从而进一步降低任务处理延迟;最后应用多接入边缘计算仿真平台进行对比实验,结果表明提出的分簇编排策略和协作缓存算法可以有效降低网络和CPU占用率,获得超低任务部署和完成时延,显著提高服务质量,并显示出强可扩展性. 展开更多
关键词 移动边缘计算 编排策略 簇头选取 协作缓存 Docker容器
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基于深度学习的云平台动态自适应任务调度
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作者 任明 沈达 《计算机技术与发展》 2024年第8期17-22,共6页
云计算环境下任务调度是优化云应用服务质量的热点研究问题,目前工业界和学术界重点关注任务调度策略。然而,现有方法依赖运维人员的系统实现知识或复杂的深度神经网络,需要较高计算资源,产生更高执行成本,难以适应动态变化的多样化任... 云计算环境下任务调度是优化云应用服务质量的热点研究问题,目前工业界和学术界重点关注任务调度策略。然而,现有方法依赖运维人员的系统实现知识或复杂的深度神经网络,需要较高计算资源,产生更高执行成本,难以适应动态变化的多样化任务类型。针对该问题,提出一种基于深度学习的云计算平台动态自适应任务调度策略。首先,从待处理任务、可用云资源及系统运行状态等三方面提取任务调度特征;其次,构建深度学习模型对特征编码,通过多头图注意力机制推理解码以预测策略的任务处理和调度执行成本;最后,根据调度收益从策略集中选择当前最优任务调度策略,同时基于迭代反馈机制计算损失函数以在线优化模型。建立虚拟化云计算服务器集群,实现典型的多种任务调度策略,模拟真实AI任务工作负载。实验结果表明,所提出策略与现有实验选取方法相比能够有效降低响应时间、执行成本及运行能耗。 展开更多
关键词 云计算 深度学习 任务调度 自适应策略 多头注意力 模型选择
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基于扇形链路策略的改进蚁群分簇路由协议
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作者 王丽芳 杨康杰 +1 位作者 郭晓东 张哲 《计算机工程与设计》 北大核心 2024年第9期2620-2626,共7页
针对网络覆盖区域较大、节点数量较多的无线传感器网络,容易出现部分节点过早死亡等情况,提出一种基于扇形链路策略的改进蚁群分簇路由协议RACO-SL。通过加入奖惩因子,同时对精英个体采用蚁群优化算法的概率生成新的后代个体,对于普通个... 针对网络覆盖区域较大、节点数量较多的无线传感器网络,容易出现部分节点过早死亡等情况,提出一种基于扇形链路策略的改进蚁群分簇路由协议RACO-SL。通过加入奖惩因子,同时对精英个体采用蚁群优化算法的概率生成新的后代个体,对于普通个体,通过与随机选择的精英个体进行交叉变异操作,改进蚁群优化算法,以整个网络每次通信的能耗为优化目标选取较优的簇头节点集。为待转发簇头节点设计从可动态调节的扇形区域中选择下一跳中继节点的链路转发策略。实验结果表明,与现有协议相比,该协议在延长网络寿命、提高通信链路质量、增强网络覆盖度方面表现良好。 展开更多
关键词 无线传感器网络 分簇路由协议 多跳 扇形链路策略 蚁群优化算法 簇头节点选择 能量均衡 网络覆盖度
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地面风对瓦里关山大气CH_4本底浓度的影响分析 被引量:16
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作者 周凌晞 温玉璞 +2 位作者 李金龙 汤洁 张晓春 《应用气象学报》 CSCD 北大核心 2004年第3期257-265,共9页
使用 1 994年 7月至 1 996年 1 2月大气CH4和地面风现场连续观测资料 ,分析了瓦里关全球大气本底基准站 ( 36°1 7′N ,1 0 0°5 4′E ,海拔 381 6m)地面风变化对大气CH4本底浓度的影响。结果表明 ,水平风向、风速和垂直风向、... 使用 1 994年 7月至 1 996年 1 2月大气CH4和地面风现场连续观测资料 ,分析了瓦里关全球大气本底基准站 ( 36°1 7′N ,1 0 0°5 4′E ,海拔 381 6m)地面风变化对大气CH4本底浓度的影响。结果表明 ,水平风向、风速和垂直风向、风速的变化对大气CH4观测值的影响在春、夏、秋、冬季有明显不同 ,水平风向NE—ENE—E为CH4测量最主要的局地影响非本底扇区 ,静风及水平风速大于 1 0m/s、垂直风速大于± 1m/s对观测结果都有较大影响 ;由观测事实的统计平均还给出了此段期间瓦里关大气CH4在不同季节的浓度分布范围和日变化类型 ,并分析了可能成因 ;将地面风数据作为大气CH4本底资料的过滤因子之一 ,提出了适用于不同使用目的和要求的我国内陆高原大气CH4本底数据筛选方法 ,本底数据留存率约为原始资料量的 5 0 % 展开更多
关键词 大气甲烷 本底变化 地面风 数据筛选 ch4
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Artificial intelligence-driven radiomics study in cancer:the role of feature engineering and modeling 被引量:1
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作者 Yuan-Peng Zhang Xin-Yun Zhang +11 位作者 Yu-Ting Cheng Bing Li Xin-Zhi Teng Jiang Zhang Saikit Lam Ta Zhou Zong-Rui Ma Jia-Bao Sheng Victor CWTam Shara WYLee Hong Ge Jing Cai 《Military Medical Research》 SCIE CAS CSCD 2024年第1期115-147,共33页
Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of... Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of clinicians.Moreover,some potentially useful quantitative information in medical images,especially that which is not visible to the naked eye,is often ignored during clinical practice.In contrast,radiomics performs high-throughput feature extraction from medical images,which enables quantitative analysis of medical images and prediction of various clinical endpoints.Studies have reported that radiomics exhibits promising performance in diagnosis and predicting treatment responses and prognosis,demonstrating its potential to be a non-invasive auxiliary tool for personalized medicine.However,radiomics remains in a developmental phase as numerous technical challenges have yet to be solved,especially in feature engineering and statistical modeling.In this review,we introduce the current utility of radiomics by summarizing research on its application in the diagnosis,prognosis,and prediction of treatment responses in patients with cancer.We focus on machine learning approaches,for feature extraction and selection during feature engineering and for imbalanced datasets and multi-modality fusion during statistical modeling.Furthermore,we introduce the stability,reproducibility,and interpretability of features,and the generalizability and interpretability of models.Finally,we offer possible solutions to current challenges in radiomics research. 展开更多
关键词 Artificial intelligence Radiomics Feature extraction Feature selection Modeling INTERPRETABILITY Multimodalities head and neck cancer
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基于节点信任的LEACH协议簇头选举改进算法 被引量:12
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作者 白林林 严斌宇 +2 位作者 罗敬文 苟旭 卢苇 《四川大学学报(工程科学版)》 EI CAS CSCD 北大核心 2012年第S1期218-223,共6页
针对LEACH协议在选举簇头时没有考虑到节点的信任值和节点的剩余能量,提出了一种新的簇头选举改进算法,即在数据传输阶段同时计算节点的信任值,为下一轮选举簇头节点作参考,从而在相对延长了网络寿命的同时确保了数据的可靠性,加强了网... 针对LEACH协议在选举簇头时没有考虑到节点的信任值和节点的剩余能量,提出了一种新的簇头选举改进算法,即在数据传输阶段同时计算节点的信任值,为下一轮选举簇头节点作参考,从而在相对延长了网络寿命的同时确保了数据的可靠性,加强了网络的安全。由于在计算节点的信任值过程中已包含节点,故不需要额外考虑节点的剩余能量。仿真结果表明,改进后的算法不仅在网络寿命上要优于LEACH算法,同时在安全性能分析上也优于LEACH协议。 展开更多
关键词 LEAch协议 簇头选举 网络寿命 信任值 安全性
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非氧条件下CH_4选择还原NO催化反应的性能 被引量:1
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作者 朱波 罗孟飞 +1 位作者 袁贤鑫 吴红丽 《石油化工》 CAS CSCD 北大核心 1996年第7期480-483,共4页
研究了不同载体、不同浸渍液制备的Pd催化剂对CH4还原NO的催化性能。结果表明,γ-Al2O3基催化剂在较温和的反应温度下(350—400℃),具有较高的反应活性和N2选择性。而Pd/γ-Al2O3-ZSM-5催化剂... 研究了不同载体、不同浸渍液制备的Pd催化剂对CH4还原NO的催化性能。结果表明,γ-Al2O3基催化剂在较温和的反应温度下(350—400℃),具有较高的反应活性和N2选择性。而Pd/γ-Al2O3-ZSM-5催化剂在相对较高的反应温度下(400—500℃),显示出较高的NO转化率和N2选择性。不同的浸渍液和催化剂预处理气体。 展开更多
关键词 钯催化剂 选择还原 甲烷 氮氧化物
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基于LEACH协议的能耗均衡路由算法 被引量:14
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作者 张浩 李腊元 《计算机工程》 CAS CSCD 北大核心 2011年第7期91-93,111,共4页
分析LEACH协议,指出其在簇头选择、簇头与基站通信方面存在的不足。针对上述问题,以均衡能耗和节省能量为出发点,结合LEACH-C的特点及Dijkstra算法对LEACH协议进行改进,提出LEACH-EB协议。仿真结果表明,LEACH-EB协议能有效节省能量,均... 分析LEACH协议,指出其在簇头选择、簇头与基站通信方面存在的不足。针对上述问题,以均衡能耗和节省能量为出发点,结合LEACH-C的特点及Dijkstra算法对LEACH协议进行改进,提出LEACH-EB协议。仿真结果表明,LEACH-EB协议能有效节省能量,均衡能量消耗,延长网络生命周期。 展开更多
关键词 无线传感器网络 LEAch协议 能耗均衡 簇头选择 簇间路由
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