A social recommendation system for academic collaboration in undergraduate research

Academic collaboration plays an important role in undergraduate research. Current methods rely on offline social contacts for undergraduate students to collaborate with academic staff members in universities and research institutions. In big data era, it is difficult for undergraduate students to find suitable research project opportunities and supervisors to work with. This paper proposes a social recommendation system for undergraduate students to find research project opportunities and work with research project teams on an academic collaboration network. The proposed recommendation method integrates relevance, connectivity, and quality modules, where profiles of undergraduates are constructed with their self‐claimed information, research activities (e.g., studying and reading research publications and reading research projects), and social connections in the academic collaboration network. Suitable research projects are recommended based on the undergraduates' profiles. Experiments are conducted, and the results have shown that the proposed social recommendation system can facilitate undergraduates' selection of research projects.     

推荐系统中推荐池的聚类算法分析

针对个性化推荐系统规模扩大而引起的实时性差、推荐精度较低等问题,提出了改进的k-均值用户聚类算法,实现对推荐系统中推荐池的压缩,将用户在不同项目簇上的评价差异作为用户距离,采用kruskal最小生成树算法生成初始聚类中心,使得初始中心靠近类中心,这样得到的聚类更符合实际.进行了算法改进前后的实验对比,结果表明,改进的聚...     

基于用户关注度的个性化新闻推荐系统

为满足用户需求,以用户为中心,解决用户关注度不断变化、数据稀疏性、优化时间和空间效率等问题,提出基于用户关注度的个性化新闻推荐系统。推荐系统引入个人兴趣和场景兴趣来描述用户关注度,使用雅克比度量用户相似性,对相似度加权求和预测用户关注度,从而提供给用户经过排序的新闻推荐列表。实验结果表明,推荐系统有效地提高了推荐精准度和覆盖度,改善了系统可扩展性和自动更新能力,具有良好的推荐效果。     

协同过滤推荐系统中聚类搜索方法研究

最近邻计算是协同过滤方法中直接影响到推荐系统的运行效率和推荐准确率的重要一环。当用户和项目数目达到一定规模的时候,推荐系统的可扩展性明显降低。聚类的方法能在一定程度上弥补这个缺陷,但同时又会带来推荐准确性的下降。提出了一种与信息检索领域中的倒排索引相结合并采用“成员策略”的用户聚类搜索算法,缩短了最近邻计算的时间,实验的结果证明,该方法能在保证推荐正确性的前提下有效改善协同过滤推荐系统的可扩展性。     

结合用户兴趣度聚类的协同过滤推荐算法

针对传统的协同过滤算法忽略了用户兴趣源于关键词以及数据稀疏的问题,提出了结合用户兴趣度聚类的协同过滤推荐算法。利用用户对项目的评分,并从项目属性中提取关键词,提出了一种新的RF-IIF （rating frequency-inverse item frequency）算法,根据目标用户对某关键词的评分频率和该关键词被所有用户的评分频率,得到用户对关键词的偏好,形成用户—关键词偏好矩阵,并在该矩阵基础上进行聚类。然后利用logistic函数得到用户对项目的兴趣度,明确用户爱好,在类簇中寻找目标用户的相似用户,提取邻居爱好的前◢N◣个物品对用户进行推荐。实验结果表明,算法准确率始终优于传统算法,对用户爱好判断较为准确,缓解了数据稀疏问题,有效提高了推荐的准确率和效率。     

An improved collaborative movie recommendation system using computational intelligence

Recommendation systems have become prevalent in recent years as they dealing with the information overload problem by suggesting users the most relevant products from a massive amount of data. For media product, online collaborative movie recommendations make attempts to assist users to access their preferred movies by capturing precisely similar neighbors among users or movies from their historical common ratings. However, due to the data sparsely, neighbor selecting is getting more difficult with the fast increasing of movies and users. In this paper, a hybrid model-based movie recommendation system which utilizes the improved K-means clustering coupled with genetic algorithms (GAs) to partition transformed user space is proposed. It employs principal component analysis (PCA) data reduction technique to dense the movie population space which could reduce the computation complexity in intelligent movie recom-mendation as well. The experiment results on Movielens dataset indicate that the proposed approach can provide high performance in terms of accuracy, and generate more reliable and personalized movie recommendations when compared with the existing methods.     

个性化推荐系统综述

信息超载是目前网络用户面临的一个严重问题,个性化推荐系统是解决该问题的一个有力工具,并受到了众多的关注和研究。给出推荐系统的定义,同时阐述了推荐系统的几项关键技术,包括用户建模、推荐对象的建模和推荐算法。后来总结了推荐系统的体系结构和性能评价指标,并尝试给出了推荐系统未来研究的重点、难点和热点问题。     

Towards a journalist-based news recommendation system: The Wesomender approach

The present paper introduces a context-aware recommendation system for journalists to enable the identification of similar topics across different sources. More specifically a journalist-based recommendation system that can be automatically configured is presented to exploit news according to expert preferences. News contextual features are also taken into account due to the their special nature: time, current user interests, location or existing trends are combined with traditional recommendation techniques to provide an adaptive framework that deals with heterogeneous data providing an enhanced collaborative filtering system. Since the Wesomender approach is able to generate context-aware recommendations in the journalism field, a quantitative evaluation with the aim of comparing Wesomender results with the expectations of a team of experts is also performed to show that a context-aware adaptive recommendation engine can fulfil the needs of journalists daily work when retrieving timely and primary information is required.     

User comments for news recommendation in forum-based social media

News recommendation and user interaction are important features in many Web-based news services. The former helps users identify the most relevant news for further information. The latter enables collaborated information sharing among users with their comments following news postings. This research is intended to marry these two features together for an adaptive recommender system that utilizes reader comments to refine the recommendation of news in accordance with the evolving topic. This then turns the traditional “push-data” type of news recommendation to “discussion” moderator that can intelligently assist online forums. In addition, to alleviate the problem of recommending essentially identical articles, the relationship (duplicate, generalization, or specialization) between recommended news articles and the original posting is investigated. Our experiments indicate that our proposed solutions provide an improved news recommendation service in forum-based social media.     

A hybrid of sequential rules and collaborative filtering for product recommendation

Customers’ purchase behavior may vary over time. Traditional collaborative filtering (CF) methods make recommendations to a target customer based on the purchase behavior of customers whose preferences are similar to those of the target customer; however, the methods do not consider how the customers’ purchase behavior may vary over time. In contrast, the sequential rule-based recommendation method analyzes customers’ purchase behavior over time to extract sequential rules in the form: purchase behavior in previous periods ⇒ purchase behavior in the current period. If a target customer’s purchase behavior history is similar to the conditional part of the rule, then his/her purchase behavior in the current period is deemed to be the consequent part of the rule. Although the sequential rule method considers the sequence of customers’ purchase behavior over time, it does not utilize the target customer’s purchase data for the current period. To resolve the above problems, this work proposes a novel hybrid recommendation method that combines the segmentation-based sequential rule method with the segmentation-based KNN-CF method. The proposed method uses customers’ RFM (Recency, Frequency, and Monetary) values to cluster customers into groups with similar RFM values. For each group of customers, sequential rules are extracted from the purchase sequences of that group to make recommendations. Meanwhile, the segmentation-based KNN-CF method provides recommendations based on the target customer’s purchase data for the current period. Then, the results of the two methods are combined to make final recommendations. Experiment results show that the hybrid method outperforms traditional CF methods.     

协同过滤算法中推荐集选取方法的研究

针对传统的基于余弦相似性的协同过滤算法中推荐集选取方法进行了改进,设计了一种新的评分方式预测用户对未评价项目的评分,从而增强了推荐的合理性。实验结果表明,该算法同传统协同过滤算法相比能显著提高推荐精度。     

Bayesian dual neural networks for recommendation

Most traditional collaborative filtering (CF) methods only use the user-item rating matrix to make recommendations, which usually suffer from cold-start and sparsity problems. To address these problems, on the one hand, some CF methods are proposed to incorporate auxiliary information such as user/item profiles; on the other hand, deep neural networks, which have powerful ability in learning effective representations, have achieved great success in recommender systems. However, these neural network based recommendation methods rarely consider the uncertainty of weights in the network and only obtain point estimates of the weights. Therefore, they maybe lack of calibrated probabilistic predictions and make overly confident decisions. To this end, we propose a new Bayesian dual neural network framework, named BDNet, to incorporate auxiliary information for recommendation. Specifically, we design two neural networks, one is to learn a common low dimensional space for users and items from the rating matrix, and another one is to project the attributes of users and items into another shared latent space. After that, the outputs of these two neural networks are combined to produce the final prediction. Furthermore, we introduce the uncertainty to all weights which are represented by probability distributions in our neural networks to make calibrated probabilistic predictions. Extensive experiments on real-world data sets are conducted to demonstrate the superiority of our model over various kinds of competitors.     

An adaptive doctor-recommender system

ABSTRACT

Recommender systems use machine-learning techniques to make predictions about resources. The medical field is one where much research is currently being conducted on recommender system utility. In the last few years, the amount of information available online that relates to healthcare has increased tremendously. Patients nowadays are more aware and look for answers to healthcare problems online. This has resulted in a dire need of an effective reliable online system to recommend the physician that is best suited to a particular patient in a limited time. In this article, a hybrid doctor-recommender system is proposed, by combining different recommendation approaches: content base, collaborative and demographic filtering to effectively tackle the issue of doctor recommendation. The proposed system addresses the issue of personalization through analysing patient's interest towards selecting a doctor. It uses a novel adoptive algorithm to construct a doctor's ranking function. Moreover, this ranking function is used to translate patients’ criteria for selecting a doctor into a numerical base rating, which will eventually be used in the recommendation of doctors. The system has been evaluated thoroughly, and result show that recommendations are reasonable and can fulfil patient's demand for reliable doctor's selection effectively.     

基于聚类免疫网络的协同过滤推荐算法

针对传统协同过滤推荐算法进行聚类后出现的推荐精度下降问题,提出了一种利用独特型网络模型对基于用户聚类的协同过滤算法加以改进的新思路。通过引入人工免疫中动态调节抗体浓度使免疫网络保持稳定的原理来调整邻居用户的数目,以保证邻居用户的多样性达到提高精度的目的。实验结果表明,该算法相对于传统的基于聚类的协同过滤算法而言,在提高推荐速度的同时保证了推荐的精度。     

基于隐式评分的推荐系统研究

为解决协同过滤推荐中“稀疏”和“冷开始”问题,提高推荐精度,提出了基于隐式评分的推荐系统。首先建立项档案,采用BP神经网络模型分析用户的导航模式和行为模式,对已点击项进行预测评分,建立用户主观评价模型和用户偏好档案;然后预测用户对未点击项评分,形成比较稠密的用户预测评分矩阵,采用协同过滤推荐技术,产生有效推荐;最后提出基于项特征的谈判模型和谈判策略,支持对推荐结果的解释和客商之间的讨价还价。     

Applying artificial immune systems to collaborative filtering for movie recommendation

Collaborative filtering is a widely used recommendation technique and many collaborative filtering techniques have been developed, each with its own merits and drawbacks. In this study, we apply an artificial immune network to collaborative filtering for movie recommendation. We propose new formulas in calculating the affinity between an antigen and an antibody and the affinity of an antigen to an immune network. In addition, a modified similarity estimation formula based on the Pearson correlation coefficient is also developed. A series of experiments based on MovieLens and EachMovie datasets are conducted, and the results are very encouraging.     

Toward a user-oriented recommendation system for real estate websites

The Internet has become a significant transaction platform for the real estate industry. However, use of the Internet does not benefit homebuyers in terms of search time, flexibility, and intuitive results. While it does encourage buyers to search more intensively, and discover and visit more properties, it also wastes more time and energy. To improve the efficiency of real estate searches, we developed an online homebuyer’s search program, based on an investigation of search behaviors, and implement a user-oriented recommendation system for real estate websites via a combination of case-based reasoning and an ontological structure. An ontological structure is employed to improve information management efficiency while case-based reasoning improves recommendation accuracy. A user test demonstrates the effectiveness of the proposed system and validates the findings of this study. The limitations of the current study are also discussed for future research and applications.     

基于大数据的高校图书馆推荐系统仿真研究

通过利用华侨大学500百万条用户日志数据的实验和分析,对高校图书馆引入推荐系统进行了定性和定量的讨论包括:高校图书馆需要推荐系统,构建推荐系统的可行性方案比较和选择,协同过滤推荐算法的介绍、比较和选择,评测指标介绍,基于系统离线评测发现了基于局部近邻学习的有效性和实施相关细节讨论.讨论和相关结论所基于的实验规模是同类讨论里较大的,对院校和工业界同行有一定参考价值.     

移动电话内容服务系统的个性化推荐

移动电话内容服务系统允许移动用户通过移动互联技术浏览、购买和下载系统内容,是当前移动增值领域研究的热点。具有较强的时空灵活性,但在信息浏览、查找方面存在明显的局限性。提出了一个基于移动电话内容服务系统的个性化推荐系统．介绍了从寻找目标用户到实现推荐的全过程。实验结果表明。所介绍的个性化推荐系统可以有助于解决内容服务系统用户访问受限、资源迷茫的问题。     

Efficient recommendation methods using category experts for a large dataset

Neighborhood-based methods have been proposed to satisfy both the performance and accuracy in recommendation systems. It is difficult, however, to satisfy them together because there is a tradeoff between them especially in a big data environment. In this paper, we present a novel method, called a CE method, using the notion of category experts in order to leverage the tradeoff between performance and accuracy. The CE method selects a few users as experts in each category and uses their ratings rather than ordinary neighbors’. In addition, we suggest CES and CEP methods, variants of the CE method, to achieve higher accuracy. The CES method considers the similarity between the active user and category expert in ratings prediction, and the CEP method utilizes the active user’s preference (interest) on each category. Finally, we combine all the approaches to create a CESP method, considering similarity and preference simultaneously. Using real-world datasets from MovieLens and Ciao, we show that our proposal successfully leverages the tradeoff between the performance and accuracy and outperforms existing neighborhood-based recommendation methods in coverage. More specifically, the CESP method provides 5% improved accuracy compared to the item-based method while performing 9 times faster than the user-based method.