Application of graph neural network and feature information enhancement in relation inference of sparse knowledge graph

At present,knowledge embedding methods are widely used in the field of knowledge graph(KG)reasoning,and have been successfully applied to those with large entities and relationships.However,in research and production environments,there are a large number of KGs with a small number of entities and relations,which are called sparse KGs.Limited by the performance of knowledge extraction methods or some other reasons(some common-sense information does not appear in the natural corpus),the relation between entities is often incomplete.To solve this problem,a method of the graph neural network and information enhancement is proposed.The improved method increases the mean reciprocal rank(MRR)and Hit@3 by 1.6%and 1.7%,respectively,when the sparsity of the FB15K-237 dataset is 10%.When the sparsity is 50%,the evaluation indexes MRR and Hit@10 are increased by 0.8%and 1.8%,respectively.

SGT-Net: A Transformer-Based Stratified Graph Convolutional Network for 3D Point Cloud Semantic Segmentation

In recent years,semantic segmentation on 3D point cloud data has attracted much attention.Unlike 2D images where pixels distribute regularly in the image domain,3D point clouds in non-Euclidean space are irregular and inherently sparse.Therefore,it is very difficult to extract long-range contexts and effectively aggregate local features for semantic segmentation in 3D point cloud space.Most current methods either focus on local feature aggregation or long-range context dependency,but fail to directly establish a global-local feature extractor to complete the point cloud semantic segmentation tasks.In this paper,we propose a Transformer-based stratified graph convolutional network(SGT-Net),which enlarges the effective receptive field and builds direct long-range dependency.Specifically,we first propose a novel dense-sparse sampling strategy that provides dense local vertices and sparse long-distance vertices for subsequent graph convolutional network(GCN).Secondly,we propose a multi-key self-attention mechanism based on the Transformer to further weight augmentation for crucial neighboring relationships and enlarge the effective receptive field.In addition,to further improve the efficiency of the network,we propose a similarity measurement module to determine whether the neighborhood near the center point is effective.We demonstrate the validity and superiority of our method on the S3DIS and ShapeNet datasets.Through ablation experiments and segmentation visualization,we verify that the SGT model can improve the performance of the point cloud semantic segmentation.

Social Robot Detection Method with Improved Graph Neural Networks

Social robot accounts controlled by artificial intelligence or humans are active in social networks,bringing negative impacts to network security and social life.Existing social robot detection methods based on graph neural networks suffer from the problem of many social network nodes and complex relationships,which makes it difficult to accurately describe the difference between the topological relations of nodes,resulting in low detection accuracy of social robots.This paper proposes a social robot detection method with the use of an improved neural network.First,social relationship subgraphs are constructed by leveraging the user’s social network to disentangle intricate social relationships effectively.Then,a linear modulated graph attention residual network model is devised to extract the node and network topology features of the social relation subgraph,thereby generating comprehensive social relation subgraph features,and the feature-wise linear modulation module of the model can better learn the differences between the nodes.Next,user text content and behavioral gene sequences are extracted to construct social behavioral features combined with the social relationship subgraph features.Finally,social robots can be more accurately identified by combining user behavioral and relationship features.By carrying out experimental studies based on the publicly available datasets TwiBot-20 and Cresci-15,the suggested method’s detection accuracies can achieve 86.73%and 97.86%,respectively.Compared with the existing mainstream approaches,the accuracy of the proposed method is 2.2%and 1.35%higher on the two datasets.The results show that the method proposed in this paper can effectively detect social robots and maintain a healthy ecological environment of social networks.

DFE-GCN: Dual Feature Enhanced Graph Convolutional Network for Controversy Detection

With the development of social media and the prevalence of mobile devices,an increasing number of people tend to use social media platforms to express their opinions and attitudes,leading to many online controversies.These online controversies can severely threaten social stability,making automatic detection of controversies particularly necessary.Most controversy detection methods currently focus on mining features from text semantics and propagation structures.However,these methods have two drawbacks:1)limited ability to capture structural features and failure to learn deeper structural features,and 2)neglecting the influence of topic information and ineffective utilization of topic features.In light of these phenomena,this paper proposes a social media controversy detection method called Dual Feature Enhanced Graph Convolutional Network(DFE-GCN).This method explores structural information at different scales from global and local perspectives to capture deeper structural features,enhancing the expressive power of structural features.Furthermore,to strengthen the influence of topic information,this paper utilizes attention mechanisms to enhance topic features after each graph convolutional layer,effectively using topic information.We validated our method on two different public datasets,and the experimental results demonstrate that our method achieves state-of-the-art performance compared to baseline methods.On the Weibo and Reddit datasets,the accuracy is improved by 5.92%and 3.32%,respectively,and the F1 score is improved by 1.99%and 2.17%,demonstrating the positive impact of enhanced structural features and topic features on controversy detection.

Source Camera Identification Algorithm Based on Multi-Scale Feature Fusion

The widespread availability of digital multimedia data has led to a new challenge in digital forensics.Traditional source camera identification algorithms usually rely on various traces in the capturing process.However,these traces have become increasingly difficult to extract due to wide availability of various image processing algorithms.Convolutional Neural Networks(CNN)-based algorithms have demonstrated good discriminative capabilities for different brands and even different models of camera devices.However,their performances is not ideal in case of distinguishing between individual devices of the same model,because cameras of the same model typically use the same optical lens,image sensor,and image processing algorithms,that result in minimal overall differences.In this paper,we propose a camera forensics algorithm based on multi-scale feature fusion to address these issues.The proposed algorithm extracts different local features from feature maps of different scales and then fuses them to obtain a comprehensive feature representation.This representation is then fed into a subsequent camera fingerprint classification network.Building upon the Swin-T network,we utilize Transformer Blocks and Graph Convolutional Network(GCN)modules to fuse multi-scale features from different stages of the backbone network.Furthermore,we conduct experiments on established datasets to demonstrate the feasibility and effectiveness of the proposed approach.

结合Graph-FPN与稳健优化的开放世界目标检测

开放世界目标检测(OWOD)要求检测图像中所有已知和未知的目标类别,同时模型必须逐步学习新的类别以自适应更新知识。针对ORE方法存在的未知目标召回率低以及增量学习的灾难性遗忘等问题,提出一种基于图特征金字塔的稳健优化开放世界目标检测方法(GARO-ORE)。首先,利用Graph-FPN中的超像素图像结构以及上下文层和层次层的分层设计,获取丰富的语义信息并帮助模型准确定位未知目标;之后,利用稳健优化方法对不确定性综合考量,提出了基于平坦极小值的基类学习策略,极大限度地保证模型在学习新类别的同时避免遗忘先前学习到的类别知识;最后,采用基于知识迁移的新增类别权值初始化方法提高模型对新类别的适应性。在OWOD数据集上的实验结果表明,GARO-ORE在未知类别召回率上取得较优的检测结果,在10+10、15+5、19+1三种增量目标检测(iOD)任务中,其mAP指标分别提升了1.38、1.42和1.44个百分点。可以看出,GARO-ORE能够较好地提高未知目标检测的召回率,并且在有效缓解旧任务灾难性遗忘问题的同时促进后续任务的学习。

STGSA:A Novel Spatial-Temporal Graph Synchronous Aggregation Model for Traffic Prediction

The success of intelligent transportation systems relies heavily on accurate traffic prediction,in which how to model the underlying spatial-temporal information from traffic data has come under the spotlight.Most existing frameworks typically utilize separate modules for spatial and temporal correlations modeling.However,this stepwise pattern may limit the effectiveness and efficiency in spatial-temporal feature extraction and cause the overlook of important information in some steps.Furthermore,it is lacking sufficient guidance from prior information while modeling based on a given spatial adjacency graph(e.g.,deriving from the geodesic distance or approximate connectivity),and may not reflect the actual interaction between nodes.To overcome those limitations,our paper proposes a spatial-temporal graph synchronous aggregation(STGSA)model to extract the localized and long-term spatial-temporal dependencies simultaneously.Specifically,a tailored graph aggregation method in the vertex domain is designed to extract spatial and temporal features in one graph convolution process.In each STGSA block,we devise a directed temporal correlation graph to represent the localized and long-term dependencies between nodes,and the potential temporal dependence is further fine-tuned by an adaptive weighting operation.Meanwhile,we construct an elaborated spatial adjacency matrix to represent the road sensor graph by considering both physical distance and node similarity in a datadriven manner.Then,inspired by the multi-head attention mechanism which can jointly emphasize information from different r epresentation subspaces,we construct a multi-stream module based on the STGSA blocks to capture global information.It projects the embedding input repeatedly with multiple different channels.Finally,the predicted values are generated by stacking several multi-stream modules.Extensive experiments are constructed on six real-world datasets,and numerical results show that the proposed STGSA model significantly outperforms the benchmarks.

基于特征图网络和多种生物信息预测关键蛋白质的深度学习框架

针对生物实验识别关键蛋白质费时费力,使用计算方法预测关键蛋白质无法有效整合生物信息的问题,提出一个深度学习框架.首先利用网络拓扑结构、基因表达数据和GO(gene ontology)注释数据构建加权蛋白质相互作用网络;然后分别使用特征图网络和双向长短期记忆细胞从亚细胞定位数据、蛋白质复合物数据和基因表达数据中提取特征向量;最后将这些特征向量输入到任务学习层预测关键蛋白质.实验结果表明,相比于现有的计算方法,该方法预测性能更好.

基于知识图谱多集池化的健康状态智能评估方法

为了从装备传感器监测数据和其他关联数据中提取更全面的时间域和空间域特征信息,提出一种基于知识图谱多集池化的健康状态评估方法。构建了带时间标签的健康知识图谱,以建模装备一段时间内监测数据、部件组成数据和先验知识间的时空依赖关系。在此基础上,设计了图多集池化网络模型,该模型通过节点特征学习、第一级图池化、自注意力特征学习和第二级图池化能够生成图谱的整体向量表示,将健康状态评估转换为基于表示学习的图谱分类任务。在公开的发动机数据集上对所提方法进行了实验评价,结果表明,该方法能够获得较高的评估准确度,在小样本情况下也表现出良好的优势。

基于图神经网络的零件机加工特征识别方法

针对现有基于深度学习的方法存在的难以识别相交特征、无法精确确定加工特征面的问题,提出基于图神经网络的加工特征识别方法.通过压缩激励模块提取节点与邻接边的特征,构建节点级与邻接边级的双层注意力网络,分割每个节点对应的加工特征.该方法充分利用了零件模型的面特征与边特征,结合零件模型的拓扑结构,基于注意力机制对特征信息进行深度学习,可以有效地解决非面合并相交特征的识别问题.在多加工特征零件数据集上,将该方法与其他3种特征识别方法进行实验对比,在准确率、平均类准确率和交并比3项指标上均取得最优结果,识别准确率高于95%.

融入三维语义特征的常识推理问答方法

现有使用预训练语言模型和知识图谱的常识问答方法主要集中于构建知识图谱子图及跨模态信息结合的研究,忽略了知识图谱自身丰富的语义特征,且缺少对不同问答任务的知识图谱子图节点相关性的动态调整,导致预测准确率低。为解决以上问题,提出一种融入三维语义特征的常识推理问答方法。首先提出知识图谱节点的关系层级、实体层级、三元组层级三维语义特征量化指标;其次,通过注意力机制动态计算关系层级、实体层级、三元组层级三种维度的语义特征对不同实体节点间的重要性;最后,通过图神经网络进行多层聚合迭代嵌入三维语义特征,获得更多的外推知识表示,更新知识图谱子图节点表示,提升答案预测精度。与QA-GNN常识问答推理方法相比,所提方法在CommonsenseQA数据集上的验证集和测试集的准确率分别提高了1.70个百分点和0.74个百分点,在OpenBookQA数据集上使用AristoRoBERTa数据处理方法的准确率提高了1.13个百分点。实验结果表明,所提出的融入三维语义特征的常识推理问答方法能够有效提高常识问答任务准确率。

结合自我特征和对比学习的推荐模型

针对图神经网络推荐中图卷积在消息传递过程的嵌入表示过平滑和噪声问题,提出一种结合自我特征和对比学习的推荐模型(SfCLRec)。采用预训练-正式训练架构训练模型,首先预训练用户和项目的嵌入表示,通过融合节点自我特征维持节点本身的特征唯一性,并引入层级对比学习任务减少来自高阶邻居节点中的噪声;其次,在正式训练阶段根据评分机制重新构建协同图邻接矩阵;最后,根据最终嵌入得到预测评分。实验结果表明,相较于LightGCN、SimGCL(Simple Graph Contrastive Learning)等现有图神经网络推荐模型,SfCLRec在3个公开数据集ML-latest-small、Last.FM和Yelp中均取得了较好的召回率和归一化折损累计增益(NDCG),验证了SfCLRec的有效性。

基于链接关系预测的弯曲密集型商品文本检测

针对商品包装文本检测任务中弯曲密集型文本导致的错检、漏检问题,提出了一种由2个子网络组成的基于链接关系预测的文本检测框架(text detection network based on relational prediction,RPTNet)。在文本组件检测网络中,下采样采用卷积神经网络和自注意力并行的双分支结构提取局部和全局特征,并加入空洞特征增强模块(DFM)减少深层特征图在降维过程中信息的丢失;上采样采用特征金字塔与多级注意力融合模块(MAFM)相结合的方式进行多级特征融合以增强文本特征间的潜在联系,通过文本检测器从上采样输出的特征图中检测文本组件;在链接关系预测网络中,采用基于图卷积网络的关系推理框架预测文本组件间的深层相似度,采用双向长短时记忆网络将文本组件聚合为文本实例。为验证RRNet的检测性能,构建了一个由商品包装图片组成的文本检测数据集(text detection dataset composed of commodity packaging,CPTD1500)。实验结果表明:RPTNet不仅在公开文本数据集CTW-1500和Total-Text上取得了优异的性能,而且在CPTD1500数据集上的召回率和F值分别达到了85.4%和87.5%,均优于当前主流算法。

基于多流语义图卷积网络的人体行为识别

与基于图像的行为识别方法相比,利用人体骨架信息进行识别能有效克服复杂背景、光照变化以及外貌变化等因素影响。但是,目前主流的基于人体骨架的行为识别方法存在参数量过大、运算速度慢等问题。对此,提出一种多流轻量级语义图卷积的行为识别方法。设计多流语义引导的图卷积网络(MS-SGN),将骨架信息分别表达为骨长流、关节流和细粒度流3种数据流形式,再对嵌入语义信息的数据流通过自适应图卷积提取空间特征,并采用不同内核和膨胀率的多尺度时域卷积提取时域特征,最后对各流分类结果进行加权融合。实验结果表明,该方法在NTU60 RGB+D数据集上的识别精度分别为90.0%(X-Sub)和95.83%(X-View),在NTU120 RGB+D数据集上的识别精度分别为83.4%(X-Sub)和84.0%(X-View),优于SGN、Logsin-RNN等主流方法,且网络框架更为轻量化。

基于动态自适应图神经网络的电动汽车充电负荷预测

电动汽车充电站负荷波动的不确定性与长时间预测任务给提升充电负荷预测精度带来巨大的挑战。文中提出一种基于动态自适应图神经网络的电动汽车充电负荷预测算法。首先,构建了一个充电负荷信息时空关联特征提取层,将多头注意力机制与自适应相关图结合生成具有时空关联性的综合特征表达式,以捕获充电站负荷的波动性;然后,将提取的特征输入到时空卷积层,捕获时间和空间之间的耦合关系;最后,通过切比雪夫多项式图卷积与多尺度时间卷积提升模型耦合长时间序列之间的能力。以Palo Alto数据集为例,与现有方法相比,所提算法在4种波动情况下的平均预测误差大幅降低。

基于时序图卷积的动态网络链路预测

动态网络链路预测广泛的应用前景,使得其逐渐成为网络科学研究的热点.动态网络链路演化过程中具有复杂的空间相关性和时间依赖性,导致其链路预测任务极具挑战.提出一个基于时序图卷积的动态网络链路预测模型(dynamic network link prediction based on sequential graph convolution, DNLP-SGC).针对网络快照序列不能有效反映动态网络连续性的问题,采用边缘触发机制对原始网络权重矩阵进行修正,弥补了离散快照表示动态网络存在时序信息丢失的不足.从网络演化过程出发,综合考虑节点间的特征相似性以及历史交互信息,采用时序图卷积提取动态网络中节点的特征,该方法融合了节点时空依赖关系.进一步,采用因果卷积网络捕获网络演化过程中潜在的全局时序特征,实现动态网络链路预测.在2个真实的网络数据集上的实验结果表明,DNLP-SGC在precision, recall, AUC指标上均优于对比的基线模型.

知识图谱特征重构下无线传感网络数据存储恢复

为了提升无线传感网络数据存储恢复成功率,保障无线传感网络数据存储安全性,提出知识图谱特征重构下无线传感网络数据存储恢复方法。通过基于知识图谱的特征重构方法优化数据存储结构;利用BP神经网络和LEACH算法,对特征重构后的数据进行融合。最后,结合多级网络编码和纠删码的原理,构建多级编码矩阵对融合数据进行多级编码,并生成多份数据副本进行存储,实现无线传感网络数据存储恢复。实验结果表明,该方法能够提升数据存储恢复成功率至90%以上,通信代价低于1.5×10^(5) Mbit/s,存储恢复时间低于0.7 ms,可以在提升恢复成功率的同时,降低存储通信代价和存储恢复时间。

基于多元语义特征和图卷积神经网络的短文本分类模型

在互联网和社交媒体迅猛发展的背景下,网络中出现了大量的短文本数据,这些数据在舆情监控、情感分析和新闻分类等自然语言处理领域展现出了非常高的经济和学术价值.但短文本数据固有的特征给短文本分类带来了不小的挑战,如文本稀疏和缺乏丰富的上下文语义等.针对这些问题,提出了一种结合多元语义特征和图卷积神经网络(GCN)的短文本分类模型,该模型通过哈尔滨工业大学的语言技术平台获取短文本的多种语义特征,并将这些语义特征同短文本一起构建一个多元异构图,然后将其作为GCN的输入,利用GCN学习短文本更深层特征,最后通过Softmax函数获取每个类别的概率分布,进而实现短文本分类.试验结果表明,本模型在短文本分类的F1评分上比传统单一模型提高了4%.

融入课程知识图谱的KMAKT预测

现有多数深度知识追踪模型的知识追踪结果的可解释性弱,且忽视了习题与知识点的内在关联性对知识追踪效果与预测结果的影响。针对上述问题,提出一种用于学生表现预测的结合课程知识图谱与多头注意力机制的知识追踪(KMAKT)模型。首先,采用Word2Vec和双向长短期记忆(Bi LSTM)网络将习题作答序列数据转换为低维稠密向量,利用图嵌入模型Trans R进行课程知识图谱嵌入表示,并使用多头注意力机制计算过往习题作答序列对当前知识状态的贡献程度;然后,通过注意力网络挖掘前驱知识对预测结果的影响程度;最后,通过多层神经网络获取预测结果,提高模型的可解释性与预测精度。实验结果表明,KMAKT模型在ASSISTments2017数据集上的受试者工作特征曲线下的面积(AUC)、准确率和F1值相比于深度知识追踪(DKT)模型分别提升了约5.20、4.20和2.40个百分点,具有较好的预测性能。在湖南大学信号与系统(HNU_SYS)子数据集上的知识追踪可视化结果验证了KMAKT模型的知识追踪结果符合教育学认知规律且具备一定程度的可解释性。

融合标签语义嵌入和图卷积的短文本特征扩展及分类方法

针对短文本长度过短、关键词偏少和标签信息利用不足造成的分类过程中面临特征稀疏和语义不明确的问题,提出了融合标签语义嵌入的图卷积网络模型。首先,在传统的术语频率和逆文档频率算法基础上,提出了融合单词所属文本的类间、类内分布关系的全局词频提取算法。其次,利用融合标签嵌入的方法,将每条训练文本与相对应的标签引入到同一个特征空间内,通过筛选聚合提取更能突显文本类别的近义词嵌入,作为文本图的文档节点的嵌入表示。最后,将文本图输入到图卷积神经网络学习后,获得的特征与预训练模型提取文本上下文的特征相融合,提升短文本的分类质量以及整个模型的泛化能力,在4个短文本数据集MR、web_snippets、R8和R52上对本文模型和14个基线算法进行了对比实验,结果表明本文提出的模型相比于对比模型具有更优的结果,在识别精度、召回率以及F_1值上有着更好的表现。