在机会网络中,网络拓扑结构动态变化,节点之间间歇性连接,这种间歇性连接是由于缺乏网络基础设施和终端设备随机移动所造成的,机会网络的这些特性使得路由算法的设计成为一项具有挑战性的研究课题.本文提出一种基于无监督学习模型X-Mean...在机会网络中,网络拓扑结构动态变化,节点之间间歇性连接,这种间歇性连接是由于缺乏网络基础设施和终端设备随机移动所造成的,机会网络的这些特性使得路由算法的设计成为一项具有挑战性的研究课题.本文提出一种基于无监督学习模型X-Means的机会网络路由算法XMROP(Opportunistic network routing algorithm based on unsupervised learning model X-Means),致力于利用机器学习模型来做出路由决策.该路由算法提出新的聚类模型应用模式,解决现阶段机会网络中应用聚类模型所存在的问题,综合考虑连接强度、节点活跃度、缓存等属性特征,定义新的节点中心度度量来衡量节点活跃程度,使用X-Means聚类模型对样本数据集进行训练,以适应机会网络拓扑结构的动态变化,提升路由算法性能.仿真实验结果表明,与KROP,DBSCAN-R,Prophet路由算法相比,XMROP具有更好的性能,从而验证了研究方案的有效性.展开更多
在微博等社交媒体的舆情发现和预测中,网络水军制造的“假热点”会影响分析准确性。为真实反映微博舆情热度,提出一种融合BERT(Bidirectional Encoder Representations from Transformers)和X-means算法的微博舆情热度分析预测模型BXpre...在微博等社交媒体的舆情发现和预测中,网络水军制造的“假热点”会影响分析准确性。为真实反映微博舆情热度,提出一种融合BERT(Bidirectional Encoder Representations from Transformers)和X-means算法的微博舆情热度分析预测模型BXpre,旨在融合微博参与用户的属性特征与热度变化的时域特征,以提高热度预测的准确性。首先,对微博原文和互动用户的数据进行预处理,利用微调后的StructBERT模型对这些数据分类,从而确定参与互动的用户与微博原文的关联度,作为用户对该微博热度增长的贡献度权重计算的参考值;其次,使用X-means算法,以互动用户的特征为依据进行聚类,基于所得聚集态的同质性特征过滤水军,并引入针对水军样本的权重惩罚机制,结合标签关联度,进一步构建微博热度指标模型;最后,通过计算先验热度值随时间变化的二阶导数与真实数据的余弦相似度预测未来微博热度变化。实验结果表明,BXpre在不同用户量级下输出的微博舆情热度排序结果更贴近真实数据,在混合量级测试条件下,BXpre的预测相关性指标达到了90.88%,相较于基于长短期记忆(LSTM)网络、极限梯度提升(XGBoost)算法和时序差值排序(TDR)的3种传统方法,分别提升了12.71、14.80和11.30个百分点;相较于ChatGPT和文心一言,分别提升了9.76和11.95个百分点。展开更多
The key pose frames of a human motion pose sequence,play an important role in the compression,retrieval and semantic analysis of continuous human motion.The current available clustering methods in literatures are diff...The key pose frames of a human motion pose sequence,play an important role in the compression,retrieval and semantic analysis of continuous human motion.The current available clustering methods in literatures are difficult to determine the number of key pose frames automatically,and may destroy the postures’ temporal relationships while extracting key frames.To deal with this problem,this paper proposes a new key pose frames extraction method on the basis of 3D space distances of joint points and the improved X-means clustering algorithm.According to the proposed extraction method,the final key pose frame sequence could be obtained by describing the posture of human body with space distance of particular joint points and then the time-constraint X-mean algorithm is applied to cluster and filtrate the posture sequence.The experimental results show that the proposed method can automatically determine the number of key frames and save the temporal characteristics of motion frames according to the motion pose sequence.展开更多
文摘在机会网络中,网络拓扑结构动态变化,节点之间间歇性连接,这种间歇性连接是由于缺乏网络基础设施和终端设备随机移动所造成的,机会网络的这些特性使得路由算法的设计成为一项具有挑战性的研究课题.本文提出一种基于无监督学习模型X-Means的机会网络路由算法XMROP(Opportunistic network routing algorithm based on unsupervised learning model X-Means),致力于利用机器学习模型来做出路由决策.该路由算法提出新的聚类模型应用模式,解决现阶段机会网络中应用聚类模型所存在的问题,综合考虑连接强度、节点活跃度、缓存等属性特征,定义新的节点中心度度量来衡量节点活跃程度,使用X-Means聚类模型对样本数据集进行训练,以适应机会网络拓扑结构的动态变化,提升路由算法性能.仿真实验结果表明,与KROP,DBSCAN-R,Prophet路由算法相比,XMROP具有更好的性能,从而验证了研究方案的有效性.
文摘在微博等社交媒体的舆情发现和预测中,网络水军制造的“假热点”会影响分析准确性。为真实反映微博舆情热度,提出一种融合BERT(Bidirectional Encoder Representations from Transformers)和X-means算法的微博舆情热度分析预测模型BXpre,旨在融合微博参与用户的属性特征与热度变化的时域特征,以提高热度预测的准确性。首先,对微博原文和互动用户的数据进行预处理,利用微调后的StructBERT模型对这些数据分类,从而确定参与互动的用户与微博原文的关联度,作为用户对该微博热度增长的贡献度权重计算的参考值;其次,使用X-means算法,以互动用户的特征为依据进行聚类,基于所得聚集态的同质性特征过滤水军,并引入针对水军样本的权重惩罚机制,结合标签关联度,进一步构建微博热度指标模型;最后,通过计算先验热度值随时间变化的二阶导数与真实数据的余弦相似度预测未来微博热度变化。实验结果表明,BXpre在不同用户量级下输出的微博舆情热度排序结果更贴近真实数据,在混合量级测试条件下,BXpre的预测相关性指标达到了90.88%,相较于基于长短期记忆(LSTM)网络、极限梯度提升(XGBoost)算法和时序差值排序(TDR)的3种传统方法,分别提升了12.71、14.80和11.30个百分点;相较于ChatGPT和文心一言,分别提升了9.76和11.95个百分点。
基金Supported by the National Natural Science Foundation of China(61303127)Project of Science and Technology Department of Sichuan Province(2014SZ0223,2014GZ0100,2015GZ0212)+1 种基金Key Program of Education Department of Sichuan Province(11ZA130,13ZA0169)Postgraduate Innovation Fund Project by Southwest University of Science and Technology(15ycx057)
文摘The key pose frames of a human motion pose sequence,play an important role in the compression,retrieval and semantic analysis of continuous human motion.The current available clustering methods in literatures are difficult to determine the number of key pose frames automatically,and may destroy the postures’ temporal relationships while extracting key frames.To deal with this problem,this paper proposes a new key pose frames extraction method on the basis of 3D space distances of joint points and the improved X-means clustering algorithm.According to the proposed extraction method,the final key pose frame sequence could be obtained by describing the posture of human body with space distance of particular joint points and then the time-constraint X-mean algorithm is applied to cluster and filtrate the posture sequence.The experimental results show that the proposed method can automatically determine the number of key frames and save the temporal characteristics of motion frames according to the motion pose sequence.
