Region-aware neural graph collaborative filtering for personalized recommendation

Personalized recommender systems have been widely deployed in various scenarios to enhance user experience in response to the challenge of information explosion.Especially,personalized recommendation models based on graph structure have advanced greatly in predicting user preferences.However,geographical region entities that reflect the geographical context of the items is not being utilized in previous works,leaving room for the improvement of personalized recommendation.This study proposes a region-aware neural graph collaborative filtering(RA-NGCF)model,which introduces the geographical regions for improving the prediction of user preference.The approach first characterizes the relationships between items and users with a user-item-region graph.And,a neural network model for the region-aware graph is derived to capture the higher-order interaction among users,items,and regions.Finally,the model fuses region and item vectors to infer user preferences.Experiments on real-world dataset results show that introducing region entities improves the accuracy of personalized recommendations.This study provides a new approach for optimizing personalized recommendation as well as a methodological reference for facilitating geographical regions for optimizing spatial applications.

Location-Aware Personalized Traveler Recommender System(LAPTA)Using Collaborative Filtering KNN

Many tourists who travel to explore different cultures and cities worldwide aim to find the best tourist sites,accommodation,and food according to their interests.This objective makes it harder for tourists to decide and plan where to go and what to do.Aside from hiring a local guide,an option which is beyond most travelers’budgets,the majority of sojourners nowadays use mobile devices to search for or recommend interesting sites on the basis of user reviews.Therefore,this work utilizes the prevalent recommender systems and mobile app technologies to overcome this issue.Accordingly,this study proposes location-aware personalized traveler assistance(LAPTA),a system which integrates user preferences and the global positioning system(GPS)to generate personalized and location-aware recommendations.That integration will enable the enhanced recommendation of the developed scheme relative to those from the traditional recommender systems used in customer ratings.Specifically,LAPTA separates the data obtained from Google locations into name and category tags.After the data separation,the system fetches the keywords from the user’s input according to the user’s past research behavior.The proposed system uses the K-Nearest algorithm to match the name and category tags with the user’s input to generate personalized suggestions.The system also provides suggestions on the basis of nearby popular attractions using the Google point of interest feature to enhance system usability.The experimental results showed that LAPTA could provide more reliable and accurate recommendations compared to the reviewed recommendation applications.

Time-Ordered Collaborative Filtering for News Recommendation

Faced with hundreds of thousands of news articles in the news websites,it is difficult for users to find the news articles they are interested in.Therefore,various news recommender systems were built.In the news recommendation,these news articles read by a user is typically in the form of a time sequence.However,traditional news recommendation algorithms rarely consider the time sequence characteristic of user browsing behaviors.Therefore,the performance of traditional news recommendation algorithms is not good enough in predicting the next news article which a user will read.To solve this problem,this paper proposes a time-ordered collaborative filtering recommendation algorithm(TOCF),which takes the time sequence characteristic of user behaviors into account.Besides,a new method to compute the similarity among different users,named time-dependent similarity,is proposed.To demonstrate the efficiency of our solution,extensive experiments are conducted along with detailed performance analysis.

A Personalized Recommendation Algorithm with User Trust in Social Network

In the era of big data, personalized recommendation has become an important research issue in social networks as it can find and match user’s preference. In this paper, the user trust is integrated into the recommendation algorithm, by dividing the user trust into 2 parts: user score trust and user preference trust. In view of the common items in user item score matrix, the algorithm combines the number of items with the score similarity between users, and establishes an asymmetric trust relationship matrix so as to calculate the user’s score trust. For the non common score items, we use the attribute information of items and the scoring weight to calculate the user’s preference trust. Based on the user trust in social network, a new collaborative filtering recommendation algorithm is proposed. Besides, a new matrix factorization recommendation algorithm is proposed by combining the user trust with matrix factorization. We did the experiments comparing with the related algorithms on the real data sets of social network. The results show that the proposed algorithms can effectively improve the accuracy of recommendation.

Privacy-Preserving Collaborative Filtering Algorithm Based on Local Differential Privacy

Mobile edge computing(MEC)is an emerging technolohgy that extends cloud computing to the edge of a network.MEC has been applied to a variety of services.Specially,MEC can help to reduce network delay and improve the service quality of recommendation systems.In a MEC-based recommendation system,users’rating data are collected and analyzed by the edge servers.If the servers behave dishonestly or break down,users’privacy may be disclosed.To solve this issue,we design a recommendation framework that applies local differential privacy(LDP)to collaborative filtering.In the proposed framework,users’rating data are perturbed to satisfy LDP and then released to the edge servers.The edge servers perform partial computing task by using the perturbed data.The cloud computing center computes the similarity between items by using the computing results generated by edge servers.We propose a data perturbation method to protect user’s original rating values,where the Harmony mechanism is modified so as to preserve the accuracy of similarity computation.And to enhance the protection of privacy,we propose two methods to protect both users’rating values and rating behaviors.Experimental results on real-world data demonstrate that the proposed methods perform better than existing differentially private recommendation methods.

Personalized travel route recommendation using collaborative filtering based on GPS trajectories

Travelling is a critical component of daily life.With new technology,personalized travel route recommendations are possible and have become a new research area.A personalized travel route recommendation refers to plan an optimal travel route between two geographical locations,based on the road networks and users’travel preferences.In this paper,we define users’travel behaviours from their historical Global Positioning System(GPS)trajectories and propose two personalized travel route recommendation methods–collaborative travel route recommendation(CTRR)and an extended version of CTRR(CTRR+).Both methods consider users’personal travel preferences based on their historical GPS trajectories.In this paper,we first estimate users’travel behaviour frequencies by using collaborative filtering technique.A route with the maximum probability of a user’s travel behaviour is then generated based on the naïve Bayes model.The CTRR+method improves the performances of CTRR by taking into account cold start users and integrating distance with the user travel behaviour probability.This paper also conducts some case studies based on a real GPS trajectory data set from Beijing,China.The experimental results show that the proposed CTRR and CTRR+methods achieve better results for travel route recommendations compared with the shortest distance path method.

Collaborative filtering recommendation algorithm based on interactive data classification

In the matrix factorization(MF)based collaborative filtering recommendation method,the most critical part is to deal with the interaction between the features of users and items.The mainstream approach is to use the inner product for MF to describe the user-item relationship.However,as a shallow model,MF has its limitations in describing the relationship between data.In addition,when the size of the data is large,the performance of MF is often poor due to data sparsity and noise.This paper presents a model called PIDC,short for potential interaction data clustering based deep learning recommendation.First,it uses classifiers to filter and cluster recommended items to solve the problem of sparse training data.Second,it combines MF and multi-layer perceptron(MLP)to optimize the prediction effect,and the limitation of inner product on the model expression ability is eliminated.The proposed model PIDC is tested on two datasets.The experimental results show that compared with the existing benchmark algorithm,the model improved the recommendation effect.

Personalized Recommendation Algorithm Based on Preference Features

A hybrid collaborative filtering algorithm based on the user preferences and item features is proposed.A thorough investigation of Collaborative Filtering （CF） techniques preceded the development of this algorithm.The proposed algorithm improved the user-item similarity approach by extracting the item feature and applying various item features＇ weight to the item to confirm different item features.User preferences for different item features were obtained by employing user evaluations of the items.It is expected that providing better recommendations according to preferences and features would improve the accuracy and efficiency of recommendations and also make it easier to deal with the data sparsity.In addition,it is expected that the potential semantics of the user evaluation model would be revealed.This would explain the recommendation results and increase accuracy.A portion of the MovieLens database was used to conduct a comparative experiment among the proposed algorithms,i.e.,the collaborative filtering algorithm based on the item and the collaborative filtering algorithm based on the item feature.The Mean Absolute Error （MAE） was utilized to conduct performance testing.The experimental results show that employing the proposed personalized recommendation algorithm based on the preference-feature would significantly improve the accuracy of evaluation predictions compared to two previous approaches.

User space transformation in deep learning based recommendation

Deep learning based recommendation methods, such as the recurrent neural network based recommendation method(RNNRec) and the gated recurrent unit(GRU) based recommendation method(GRURec), are proposed to solve the problem of time heterogeneous feedback recommendation. These methods out-perform several state-of-the-art methods. However, in RNNRec and GRURec, action vectors and item vectors are shared among users. The different meanings of the same action for different users are not considered. Similarly, different user preference for the same item is also ignored. To address this problem, the models of RNNRec and GRURec are modified in this paper. In the proposed methods, action vectors and item vectors are transformed into the user space for each user firstly, and then the transformed vectors are fed into the original neural networks of RNNRec and GRURec. The transformed action vectors and item vectors represent the user specified meaning of actions and the preference for items, which makes the proposed method obtain more accurate recommendation results. The experimental results on two real-life datasets indicate that the proposed method outperforms RNNRec and GRURec as well as other state-of-the-art approaches in most cases.

UP-TreeRec: Building Dynamic User Profiles Tree for News Recommendation

Online news recommendation systems aim to address the information explosion of news and make personalized recommendations for users. The key problem of personalized news recommendation is to model users' interests and track their changes. A common way to deal with the user modeling problem is to build user profiles from observed behavior. However, the majority of existing methods make static representations of user profiles and little research has focused on effective user modeling that could dynamically capture user interests in news topics. To address this problem, in this paper, we propose UP-TreeRec, a news recommendation framework based on a user profile tree(UP-Tree), which is a novel framework combining content-based and collaborative filtering techniques. First, by exploiting a novel topic model namely UILDA, we obtain the representation vectors for news content in a topic space as the fundamental bridge to associate user interests with news topics. Next, we design a decision tree with a dynamically changeable structure to construct a user interest profile from the user's feedback. Furthermore, we present a clustering-based multidimensional similarity computation method to select the nearest neighbor of the UP-Tree efficiently. We also provide a Map-Reduce framework-based implemen-tation that enables scaling our solution to real-world news recommendation problems. We conducted several experiments compared to the state-of-the-art approaches on real-world datasets and the experimental results demonstrate that our approach significantly improves accuracy and effectiveness in news recommendation.

基于Apriori与User-CF的银行客户挖掘及个性化推荐

大数据技术的发展向银行的数据挖掘能力提出新要求,因此加强银行智能化服务,提升银行的金融服务能力对提升银行的客户满意度具有现实意义。采用Apriori关联规则算法,分析办理业务的各类型客户间的关联规则,有利于挖掘能够发展转化为个贷客户的潜在新用户;为此,本研究分别构建余弦相似度与Pearson相似度的协同过滤算法,预测客户对未知类型产品的偏好程度,根据相关评分将相应产品推荐给客户。结果表明,通过Apriori关联规则算法与协同过滤算法,能够有效提高数据的分析管理能力,助力银行挖掘新客户,深度培育基础客户,为客户提供更加个性化、人性化的服务系统,加强银行智能化服务,从而提升银行的金融服务能力。

考虑数据稀疏性的图书推荐协同过滤算法仿真

图书推荐算法易忽略数据稀疏性问题,导致推荐结果与用户感兴趣内容之间存在较大的偏差。在考虑数据稀疏性的基础上提出一种图书推荐协同过滤算法,对数据预处理,通过对用户和用户之间综合信任度分析,利用分布估计算法对用户兴趣建模;构建用户兴趣簇类集,划分用户兴趣,从中选择出与检索对象最接近的邻居;计算邻近项目得分,按照从大到小的顺序排列,排名靠前的资源项即为图书推荐结果。实验结果表明,所提方法在推荐500本图书时,用时在12s内,且降低了平均绝对误差和均方根误差,实现了最精准的图书推荐。

Representation learning: serial-autoencoder for personalized recommendation

Nowadays,the personalized recommendation has become a research hotspot for addressing information overload.Despite this,generating effective recommendations from sparse data remains a challenge.Recently,auxiliary information has been widely used to address data sparsity,but most models using auxiliary information are linear and have limited expressiveness.Due to the advantages of feature extraction and no-label requirements,autoencoder-based methods have become quite popular.However,most existing autoencoder-based methods discard the reconstruction of auxiliary information,which poses huge challenges for better representation learning and model scalability.To address these problems,we propose Serial-Autoencoder for Personalized Recommendation(SAPR),which aims to reduce the loss of critical information and enhance the learning of feature representations.Specifically,we first combine the original rating matrix and item attribute features and feed them into the first autoencoder for generating a higher-level representation of the input.Second,we use a second autoencoder to enhance the reconstruction of the data representation of the prediciton rating matrix.The output rating information is used for recommendation prediction.Extensive experiments on the MovieTweetings and MovieLens datasets have verified the effectiveness of SAPR compared to state-of-the-art models.

智能推荐系统在高校选课中的应用

在信息化时代,个性化教育对当今社会至关重要。针对高校选课系统在当今人才培养过程中缺乏推荐等专家辅助系统。人工智能中的推荐系统可以通过传统的推荐算法综合评估得出推荐序列,实现高校选课推荐等个性化服务。基于此,提出了利用智能推荐系统中的协同过滤和内容推荐两种方式混合推荐,帮助实现个性化学习,向专业化培养目标靠近,为学习者提供智能化的辅助指导。同时,推动高校教育更好地进行个性化培养,加快推进人工智能与教育的深度融合和创新发展,促进人才培养模式和传统教育模式更好地向智能教育转变。

基于核方法的User-Based协同过滤推荐算法

作为在实际系统中运用最为广泛和成功的推荐技术,协同过滤算法得到了研究者们的广泛关注.传统的协同过滤算法面临着数据稀疏和冷启动等问题的挑战,在计算用户之间相似度时只能考虑有限的数据,因此难以对用户之间的相似度进行准确的估计.提出了一种基于核密度估计的用户兴趣估计模型,并基于此模型,提出了一种基于核方法的user-based协同过滤推荐算法.通过挖掘用户在有限的评分数据上表现出来的潜在兴趣,该算法能更好地描述用户兴趣在项目空间上的分布,进而可以更好地估计用户之间的兴趣相似度.实验表明,该算法可以有效地提高推荐系统的性能,尤其在数据稀疏的情况下能显著地提高推荐结果的质量.

基于标签挖掘的个性化推荐算法

基于标签的推荐算法中存在两个主要缺陷,缺乏用户对于标签偏好值的量化,以及不同标签在用户使用中所占权重。为此提出一种从标签角度出发的个性化推荐算法。分析用户历史行为中使用过的标签,根据用户历史行为建立用户的标签兴趣模型,利用标签兴趣模型计算用户对不同标签的偏好值;统计用户的历史评分记录,计算不同标签所占权重;将两者进行线性组合,得出用户对标签的兴趣度。利用余弦相似度,计算用户偏好相似度,将用户偏好相似度引入到矩阵分解模型中,进行项目评分预测和推荐。实验结果表明,在MovieLens数据集上,该算法相比于传统算法LFM和SVD++在RMSE上分别降低了5.00%和1.41%,在MAE上分别降低了5.07%和1.00%。

GNRF:基于关系融合的图神经网络推荐系统

当前的推荐方法普遍引入知识图谱作为辅助信息来缓解协同过滤算法的缺陷,如数据稀疏和冷启动问题.然而,基于知识图谱的推荐方法大都专注于利用知识图谱来构建用户及物品的特征表示,忽略了对用户交互信息的有效利用.本文在引入用户-物品交互图和知识图谱两种图结构信息基础上,通过图神经网络融合用户-物品间的交互特征、物品间的相似特征以及知识图谱中实体的知识特征,来构建用户物品的特征表示,并将之应用于推荐系统.实验表明,相对于基线模型,本文提出的模型具有较好的推荐效果.

基于数据挖掘和聚类分析的协同过滤推荐算法

为了提高推荐系统的可扩展性和用户满意度,设计基于数据挖掘和聚类分析的协同过滤推荐算法。基于双向关联规则原理,构建标签资源矩阵,利用K-means聚类算法对标签进行聚类。结合用户偏好标签,算法能计算标签与资源的紧密程度,实现基本推荐。通过标签计算用户与资源的兴趣度,实现个性化推荐。将基本推荐和个性化推荐线性组合,得出最终结果。实验表明,该算法不仅能保持数据集的平衡状态,准确性也高。通过聚类捕捉更复杂的用户兴趣模式,显著提高了推荐结果的命中率和NDCG值,为用户提供更符合个性化需求的资源。

基于用户属性和生成对抗网络的推荐系统

为提升推荐精度,解决传统推荐算法在用户评分向量中存在的未评分项语义模糊造成的推荐精度下降问题,提出一种基于用户属性的条件生成对抗网络的推荐方法。将用户的属性特征进行提取和编码,并作为生成对抗网络的条件,通过这种明确信号指导用户偏好的生成并进行推荐。在两个公开的电影评分数据集上进行实验,实验结果表明,所提方法可以有效改善推荐精度,在各评价指标上均优于现有方法,具有一定实用价值。