1,029 research outputs found
An Adapted Approach for User Profiling in a Recommendation System: Application to Industrial Diagnosis
In this paper, we propose a global architecture of a recommender tool, which represents a part of an existing collaborative platform. This tool provides diagnostic documents for industrial operators. The recommendation process considered here is composed of three steps: Collecting and filtering information; Prediction or recommendation step; evaluating and improvement. In this work, we focus on collecting and filtering step. We mainly use information result from collaborative sessions and documents describing solutions that are attributed to the complex diagnostic problems. The developed tool is based on collaborative filtering that operates on users' preferences and similar responses
Collaborative filtering for recommender systems with implicit feedback
openRecommending the right products to the customers can significantly increase the
sales of an e-commerce, and the presence of huge amounts of transactional data
makes data-driven solutions the best choice for the recommender systems in many
circumstances. In this work, a general overview of the recommendation task is
given, then several data-driven methods are compared on a real world company
data. In particular, the effort is centered around implicit feedback, i.e. binary data
such as sales, and collaborative filtering, that is the usage of community behavior
in the suggestions computation. Finally, different ways to handle cold starts, that
are new customers, are discussed and compared.Recommending the right products to the customers can significantly increase the
sales of an e-commerce, and the presence of huge amounts of transactional data
makes data-driven solutions the best choice for the recommender systems in many
circumstances. In this work, a general overview of the recommendation task is
given, then several data-driven methods are compared on a real world company
data. In particular, the effort is centered around implicit feedback, i.e. binary data
such as sales, and collaborative filtering, that is the usage of community behavior
in the suggestions computation. Finally, different ways to handle cold starts, that
are new customers, are discussed and compared
Computational intelligent methods for trusting in social networks
104 p.This Thesis covers three research lines of Social Networks. The first proposed reseach line is related with Trust. Different ways of feature extraction are proposed for Trust Prediction comparing results with classic methods. The problem of bad balanced datasets is covered in this work. The second proposed reseach line is related with Recommendation Systems. Two experiments are proposed in this work. The first experiment is about recipe generation with a bread machine. The second experiment is about product generation based on rating given by users. The third research line is related with Influence Maximization. In this work a new heuristic method is proposed to give the minimal set of nodes that maximizes the influence of the network
Clustering-Based Personalization
Recommendation systems have been the most emerging technology in the last decade as one of the key parts in e-commerce ecosystem. Businesses offer a wide variety of items and contents through different channels such as Internet, Smart TVs, Digital Screens, etc. The number of these items sometimes goes over millions for some businesses. Therefore, users can have trouble finding the products that they are looking for. Recommendation systems address this problem by providing powerful methods which enable users to filter through large information and product space based on their preferences. Moreover, users have different preferences. Thus, businesses can employ recommendation systems to target more audiences by addressing them with personalized content. Recent studies show a significant improvement of revenue and conversion rate for recommendation system adopters. Accuracy, scalability, comprehensibility, and data sparsity are main challenges in recommendation systems. Businesses need practical and scalable recommendation models which accurately personalize millions of items for millions of users in real-time. They also prefer comprehensible recommendations to understand how these models target their users. However, data sparsity and lack of enough data about items, users and their interests prevent personalization models to generate accurate recommendations. In Chapter 1, we first describe basic definitions in recommendation systems. We then shortly review our contributions and their importance in this thesis. Then in Chapter 2, we review the major solutions in this context. Traditional recommendation system methods usually make a rating matrix based on the observed ratings of users on items. This rating matrix is then employed in different data mining techniques to predict the unknown rating values based on the known values. In a novel solution, in Chapter 3, we capture the mean interest of the cluster of users on the cluster of items in a cluster-level rating matrix. We first cluster users and items separately based on the known ratings. In a new matrix, we then present the interest of each user clusters on each item clusters by averaging the ratings of users inside each user cluster on the items belonging to each item cluster. Then, we apply the matrix factorization method on this coarse matrix to predict the future cluster-level interests. Our final rating prediction includes an aggregation of the traditional user-item rating predictions and our cluster-level rating predictions. Generating personalized recommendation for cold-start users, or users with only few feedback, is a big challenge in recommendation systems. Employing any available information from these users in other domains is crucial to improve their recommendation accuracy. Thus, in Chapter 4, we extend our proposed clustering-based recommendation model by including the auxiliary feedback in other domains. In a new cluster-level rating matrix, we capture the cluster-level interests between the domains to reduce the sparsity of the known ratings. By factorizing this cross-domain rating matrix, we effectively utilize data from auxiliary domains to achieve better recommendations in the target domain, especially for cold-start users. In Chapter 5, we apply our proposed clustering-based recommendation system to Morphio platform used in a local digital marketing agency called Arcane inc. Morphio is an smart adaptive web platform, which is designed to help Arcane to produce smart contents and target more audiences. In Morphio, agencies can define multiple versions of content including texts, images, colors, and so on for their web pages. A personalization module then matches a version of content to each user using their profiles. Our ongoing real time experiment shows a significant improvement of user conversion employing our proposed clustering-based personalization. Finally, in Chapter 6, we present a summary and conclusions for this thesis. Parts of this thesis were submitted or published in peer-review journal and conferences including ACM Transactions on Knowledge Discovery from Data and ACM Conferences on Recommender Systems
Together or Alone: The Price of Privacy in Collaborative Learinig
Machine learning algorithms have reached mainstream status and are widely deployed in many applications. The accuracy of such algorithms depends significantly on the size of the underlying training dataset; in reality a small or medium sized organization often does not have the necessary data to train a reasonably accurate model. For such organizations, a realistic solution is to train their machine learning models based on their joint dataset (which is a union of the individual ones). Unfortunately, privacy concerns prevent them from straightforwardly doing so. While a number of privacy-preserving solutions exist for collaborating organizations to securely aggregate the parameters in the process of training the models, we are not aware of any work that provides a rational framework for the participants to precisely balance the privacy loss and accuracy gain in their collaboration. In this paper, by focusing on a two-player setting, we model the collaborative training process as a two-player game where each player aims to achieve higher accuracy while preserving the privacy of its own dataset. We introduce the notion of Price of Privacy, a novel approach for measuring the impact of privacy protection on the accuracy in the proposed framework. Furthermore, we develop a game-theoretical model for different player types, and then either find or prove the existence of a Nash Equilibrium with regard to the strength of privacy protection for each player. Using recommendation systems as our main use case, we demonstrate how two players can make practical use of the proposed theoretical framework, including setting up the parameters and approximating the non-trivial Nash Equilibrium
Social Influence Bias in Online Ratings: A Field Experiment
The aim of this paper is to study the empirical phenomenon of rating bubbles, i.e. clustering on extremely positive values in e-commerce platforms and rating web sites. By means of a field experiment that exogenously manipulates prior ratings for a hotel in an important Italian tourism destination, we investigate whether consumers are influenced by prior ratings when evaluating their stay (i.e., social influence bias). Results show that positive
social influence exists, and that herd behavior is asymmetric: information on prior positive ratings has a stronger influence on consumers’ rating attitude than information on prior mediocre ratings. Furthermore, we are able to exclude any brag-or-moan effect: the behavior of frequent reviewers, on average, is not statistically different from the behavior of consumers who have never posted ratings online. Yet, non-reviewers exhibit a higher influence
to excellent prior ratings, thus lending support to the social influence bias interpretation. Finally, also repeat customers are affected by prior ratings, although to a lesser extent with respect to new customers
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