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1.
针对以往模型在对点击通过率(click-through rate,CTR)进行建模预测时,存在着特征重要性学习不足、特征交互低效等问题,提出了一种增强型注意力网络预估模型,用于动态学习特征重要性和特征交互信息,模型主要由注意力层、双线性交互层和全连接神经网络层构成。注意力层的多尺度多头自注意力机制通过设置不同尺寸子空间增强特征重要性学习能力,在得到特征重要性后,进一步采用张量积双线性交互学习特征交互信息。通过对注意力的子空间尺寸大小、张量积交互形式、神经网络层数和节点个数等进行定量分析,确定模型的最佳参数。实验证明,该模型相比已有模型拥有更好的预测能力。  相似文献   

2.
有效的特征交互,对于工业推荐系统中点击通过率(click-through-rate,CTR)预估的准确性起着至关重要的作用。以往并行结构的CTR预估模型通过将独立的浅层模型和深层模型并行连接,以此来学习特征的低阶交互和高阶交互。但是,这些模型存在浅层模型准确性低、未考虑特征交互时的多语义问题、参数过多、深层模型过度泛化等问题。基于上述问题,提出了一种基于域矩阵因子分解机的点击通过率预估增强网络,通过引入域矩阵优化浅层模型中的交互,提高运算效率,并在深层模型的DNN层与层之间增加了桥接模块,在每层高阶交互后增强对原始特征的记忆能力,将浅层模型和深层模型的结果相加并归一化得到预测值。该模型在Criteo、KKBox、Frappe和MovieLens数据集上进行了大量实验,展现了优秀的预测能力。  相似文献   

3.
准确地预测社交网络中的信息扩散节点可以对谣言、计算机病毒等不良信息的传播以及信息泄露做到早检测、早溯源和早抑制。为了提高微观扩散预测精度,该文提出了一个基于多特征融合和深度学习的微观信息扩散预测通用框架(MFFDLP)。为了获取信息扩散的时序特征,基于信息扩散序列和社交网络图,采用门控循环神经网络提取局部时序特征和全局时序特征,并融合形成信息扩散序列表征;为了获取用户交互行为和兴趣爱好的动态表示,根据历史信息构建信息扩散图,使用级联图注意力网络提取信息扩散子图中节点特征和边特征,并通过嵌入查找,融合形成当前信息扩散序列中相应节点的动态扩散表征;使用双多头注意力机制,进一步捕获静态和动态扩散特征的上下文信息,实现了高精度微观扩散预测。在3个公共数据集上的对比实验结果表明:所提方法优于对比方法,在微观扩散预测的精度上最高提高了9.98%。  相似文献   

4.
现有的多行为推荐系统未有效利用不同层次的图传播信息,难以捕获用户不同行为的影响。为解决此问题,文章提出了一种基于图注意力网络的多行为推荐模型(GABR):首先,采用小批量采样节点嵌入方法聚合同一行为类型交互的邻域节点,以提高特征表示效率;接着,采用注意力机制学习不同行为类型的影响系数,以进一步融合节点特征;然后,合并多层用户和项目表示,以有效利用不同层次的图传播信息;最后,将已交互的用户-项目对和随机采样未交互过的用户-项目对作为正负样本对来训练目标模型,以优化模型性能。为验证模型推荐性能,在3个真实数据集(Yelp、Scholat、Beibei)上与现有9种推荐模型进行对比。实验结果表明GABR模型能够有效利用融合了不同行为类型影响系数的多层图传播信息,更好地预测用户偏好:在3个真实数据集上,与目前最佳的基线模型(GNMR)相比,GABR模型的HR、NDCG平均提高了1.73%、2.43%。  相似文献   

5.
多数图神经网络(Graph Neural Networks, GNN)通过设计复杂的节点信息传递和聚合方式,以提升节点分类等图分析任务的实验表现,而本文提出了一种无需信息传递和聚合的图多层感知机(Multi-Layer Perceptron, MLP)模型A&T-MLP,利用属性和拓扑信息引导的对比损失来增强模型表征能力。A&T-MLP首先使用属性矩阵和邻接矩阵计算节点间的属性和拓扑相似度;然后使用基于相似度信息引导的对比损失,增大特征空间中相似节点的一致性和不相似节点的差异性;最后构建多层感知机模型并引入交叉熵损失进行端到端训练。在节点分类任务中,A&T-MLP表现优于基线模型,Wikipedia数据集上的Micro-F1和Macro-F1相较GNN模型图卷积网络(Graph Convolutional Network, GCN)提升了15.86%和13.64%。实验结果表明,A&T-MLP能够通过对比损失保留丰富原始图的信息,提升模型性能。此外,A&T-MLP在处理拓扑信息不准确的图数据时具有较为明显的优势,即使在缺失80%拓扑信息的极端情况...  相似文献   

6.
案件罪名预测任务是基于文本数据去预测案件所属罪名.针对现有方法在相似罪名和长尾数据集上表现不佳的问题,提出了一种基于图注意力网络的案件罪名预测方法CP-GAT(charge prediction based on graph attention network).该方法首先使用司法文书数据集中的案例事件描述文本和案例对应的法条信息建立异质图结构数据,构建后的异质图包含两种类型的节点(词节点、案例节点),两种类型的边(词节点与词节点相连的边,词节点与案例节点相连的边).在基于法律文本构建后的异质图上使用图注意力网络进行图特征提取,最后将得到的特征向量输入到罪名预测的分类器中,得到案例所属的罪名.在CAIL2018法律数据集上的实验结果表明,基于图注意力网络的罪名预测方法优于对比实验使用的方法,准确率和宏观F1值分别达到了95.2%和66.1,验证了提出的方法有利于提升案件罪名预测任务的性能.  相似文献   

7.
提出了多种基于子图结构特征的新特征,构建了基于节点重要性、基于节点共同邻居、基于边共同邻居、基于邻居子图和基于边子图五类特征,并将这五类特征中的多种特征分别作为特征输入,运用机器学习的方法,实现科学家合作网未来合作关系的预测。研究中发现,基于边子图特征的链路预测准确率最好。此外,研究中运用基于模型的特征排序和最大信息系数特征选择方法分析类内特征的影响力以及相互关系,通过机器学习算法的分类模型进行链路预测。该方法能够有效地揭示网络类内特征在预测中的重要性和相关性,有利于发现影响力大的特征和冗余特征。  相似文献   

8.
针对目前的多属性群决策研究中很少考虑信息交互环节等问题,提出一种基于直觉模糊动态信息交互的多属性群决策模型。模型中用直觉模糊集表示决策属性值,通过定义两直觉模糊集的相似度,计算各个专家对方案的偏好矢量与理想方案偏好矢量间的相似度。通过计算群体的平均相似度和专家的决策偏差,若决策偏差大于给定阈值,则通过信息交互对决策偏好进行修正,直到所有的专家的决策偏差都小于给定阈值为止。计算各个方案与理想方案的加权相似度,按加权相似度排列,根据加权相似度最大原则选出最优方案。最后,通过结合1个实际案例讨论本模型的实施步骤,并与未考虑动态信息交互的模糊动态信息群决策方法进行比较,结果证明它是可行和有效的。  相似文献   

9.
无结构对等模型应用于很多领域,但其常用的Flooding等盲目搜索方式产生大量冗余消息,限制了带宽,易造成网络拥塞。针对传统发现方法中存在的问题,提出了一种基于节点兴趣相似度的资源发现方法,在分组的基础上,根据节点的兴趣相似度将相似节点划分为域,请求消息首先在域内同组节点中转发,搜索过程中动态调整网络拓扑,有效减少路由跳数,降低冗余消息量。通过仿真试验对该方法的搜索效率进行了分析验证。  相似文献   

10.
为了提高推荐算法的推荐性能,针对现有的图卷积神经网络(graph convolutional neural network, GCN)的推荐算法中,2-3层的传播网络结构不利于较远距离节点之间进行信息交互,而加深网络层数又会导致性能急剧下降的问题,提出一种特征规范化的图卷积神经网络推荐算法。该方法为传播网络中每一层输出特征进行规范化处理,避免节点嵌入表示随着网络层数增加而变得过于相似;在预测阶段,使用自注意力机制(self-attention mechanism, SA)将各层的输出进行连接,以获得更好的节点最终表示。在3个真实数据集上与传统算法以及现有同类型推荐算法进行对比,验证了该模型的有效性。实验结果表明,所提模型与基准模型相比,在召回率Recall@N和归一化折损累计增益NDCG@N上有明显提高,平均提升1.675%,最高可提升3.406%。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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