Université de Fribourg

Similarity from multi-dimensional scaling: solving the accuracy and diversity dilemma in information filtering

Zeng, Wei ; Zeng, An ; Liu, Hao ; Shang, Ming-Sheng ; Zhang, Yi-Cheng

In: PLoS ONE, 2014, vol. 9, no. 10, p. e111005

Recommender systems are designed to assist individual users to navigate through the rapidly growing amount of information. One of the most successful recommendation techniques is the collaborative filtering, which has been extensively investigated and has already found wide applications in e-commerce. One of challenges in this algorithm is how to accurately quantify the similarities of user pairs...

Université de Fribourg

Information filtering in sparse online systems: recommendation via semi-local diffusion

Zeng, Wei ; Zeng, An ; Shang, Ming-Sheng ; Zhang, Yi-Cheng

In: PLoS ONE, 2013, vol. 8, no. 11, p. e79354

With the rapid growth of the Internet and overwhelming amount of information and choices that people are confronted with, recommender systems have been developed to effectively support users’ decision-making process in the online systems. However, many recommendation algorithms suffer from the data sparsity problem, i.e. the user-object bipartite networks are so sparse that algorithms cannot...

Université de Fribourg

Membership in social networks and the application in information filtering

Zeng, Wei ; Zeng, An ; Shang, Ming-Sheng ; Zhang, Yi-Cheng

In: The European Physical Journal B, 2013, vol. 86, no. 9, p. 1-7

During the past few years, users’ membership in the online system (i.e. the social groups that online users joined) were widely investigated. Most of these works focus on the detection, formulation and growth of online communities. In this paper, we study users’ membership in a coupled system which contains user-group and user- object bipartite networks. By linking users’ membership...

Université de Fribourg

Extracting the Information Backbone in Online System

Zhang, Qian-Ming ; Zeng, An ; Shang, Ming-Sheng

In: PLoS ONE, 2013, vol. 8, no. 5, p. e62624

Information overload is a serious problem in modern society and many solutions such as recommender system have been proposed to filter out irrelevant information. In the literature, researchers have been mainly dedicated to improving the recommendation performance (accuracy and diversity) of the algorithms while they have overlooked the influence of topology of the online user-object bipartite...

Université de Fribourg

Identifying influential nodes in complex networks

Lü, Linyuan ; Shang, Ming-Sheng ; Zhang, Yi-Cheng ; Zhou, Tao

In: Physica A: Statistical Mechanics and its Applications, 2011, vol. 391, no. 4, p. 1777–1787

Identifying influential nodes that lead to faster and wider spreading in complex networks is of theoretical and practical significance. The degree centrality method is very simple but of little relevance. Global metrics such as betweenness centrality and closeness centrality can better identify influential nodes, but are incapable to be applied in large-scale networks due to the computational...

Université de Fribourg

Similarity-based classification in partially labeled networks

Zhang, Qian-Ming ; Shang, Ming-Sheng ; Lü, Linyuan

In: International Journal of Modern Physics C, 2010, vol. 21, no. 6, p. 813-824

Two main difficulties in the problem of classification in partially labeled networks are the sparsity of the known labeled nodes and inconsistency of label information. To address these two difficulties, we propose a similarity-based method, where the basic assumption is that two nodes are more likely to be categorized into the same class if they are more similar. In this paper, we introduce ten...

Université de Fribourg

Empirical comparison of local structural similarity indices for collaborative-filtering-based recommender systems

Zhang, Qian-Ming ; Shang, Ming-Sheng ; Zeng, Wei ; Chen, Yong ; Lü, Linyuan

In: Physics Procedia, 2010, vol. 3, no. 5, p. 1887-1896

Collaborative filtering is one of the most successful recommendation techniques, which can effectively predict the possible future likes of users based on their past preferences. The key problem of this method is how to define the similarity between users. A standard approach is using the correlation between the ratings that two users give to a set of objects, such as Cosine index and Pearson...