173 research outputs found
BoostFM: Boosted Factorization Machines for Top-N Feature-based Recommendation
Feature-based matrix factorization techniques such as Factorization Machines (FM) have been proven to achieve impressive accuracy for the rating prediction task. However, most common recommendation scenarios are formulated as a top-N item ranking problem with implicit feedback (e.g., clicks, purchases)rather than explicit ratings. To address this problem, with both implicit feedback and feature information, we propose a feature-based collaborative boosting recommender called BoostFM, which integrates boosting into factorization models during the process of item ranking. Specifically, BoostFM is an adaptive boosting framework that linearly combines multiple homogeneous component recommenders, which are repeatedly constructed on the basis of the individual FM model by a re-weighting scheme. Two ways are proposed to efficiently train the component recommenders from the perspectives of both pairwise and listwise Learning-to-Rank (L2R). The properties of our proposed method are empirically studied on three real-world datasets. The experimental results show that BoostFM outperforms a number of state-of-the-art approaches for top-N recommendation
Recommendation Systems: An Insight Into Current Development and Future Research Challenges
Research on recommendation systems is swiftly producing an abundance of novel methods, constantly challenging the current state-of-the-art. Inspired by advancements in many related fields, like Natural Language Processing and Computer Vision, many hybrid approaches based on deep learning are being proposed, making solid improvements over traditional methods. On the downside, this flurry of research activity, often focused on improving over a small number of baselines, makes it hard to identify reference methods and standardized evaluation protocols. Furthermore, the traditional categorization of recommendation systems into content-based, collaborative filtering and hybrid systems lacks the informativeness it once had. With this work, we provide a gentle introduction to recommendation systems, describing the task they are designed to solve and the challenges faced in research. Building on previous work, an extension to the standard taxonomy is presented, to better reflect the latest research trends, including the diverse use of content and temporal information. To ease the approach toward the technical methodologies recently proposed in this field, we review several representative methods selected primarily from top conferences and systematically describe their goals and novelty. We formalize the main evaluation metrics adopted by researchers and identify the most commonly used benchmarks. Lastly, we discuss issues in current research practices by analyzing experimental results reported on three popular datasets
RecRules: Recommending IF-THEN Rules for End-User Development
Nowadays, end users can personalize their smart devices and web applications by defining or reusing IF-THEN rules through dedicated End-User Development (EUD) tools. Despite apparent simplicity, such tools present their own set of issues. The emerging and increasing complexity of the Internet of Things, for example, is barely taken into account, and the number of possible combinations between triggers and actions of different smart devices and web applications is continuously growing. Such a large design space makes end-user personalization a complex task for non-programmers, and motivates the need of assisting users in easily discovering and managing rules and functionality, e.g., through recommendation techniques. In this paper, we tackle the emerging problem of recommending IF-THEN rules to end users by presenting RecRules, a hybrid and semantic recommendation system. Through a mixed content and collaborative approach, the goal of RecRules is to recommend by functionality: it suggests rules based on their final purposes, thus overcoming details like manufacturers and brands. The algorithm uses a semantic reasoning process to enrich rules with semantic information, with the aim of uncovering hidden connections between rules in terms of shared functionality. Then, it builds a collaborative semantic graph, and it exploits different types of path-based features to train a learning to rank algorithm and compute top-N recommendations. We evaluate RecRules through different experiments on real user data extracted from IFTTT, one of the most popular EUD tool. Results are promising: they show the effectiveness of our approach with respect to other state-of-the-art algorithms, and open the way for a new class of recommender systems for EUD that take into account the actual functionality needed by end users
Spatial Object Recommendation with Hints: When Spatial Granularity Matters
Existing spatial object recommendation algorithms generally treat objects
identically when ranking them. However, spatial objects often cover different
levels of spatial granularity and thereby are heterogeneous. For example, one
user may prefer to be recommended a region (say Manhattan), while another user
might prefer a venue (say a restaurant). Even for the same user, preferences
can change at different stages of data exploration. In this paper, we study how
to support top-k spatial object recommendations at varying levels of spatial
granularity, enabling spatial objects at varying granularity, such as a city,
suburb, or building, as a Point of Interest (POI). To solve this problem, we
propose the use of a POI tree, which captures spatial containment relationships
between POIs. We design a novel multi-task learning model called MPR (short for
Multi-level POI Recommendation), where each task aims to return the top-k POIs
at a certain spatial granularity level. Each task consists of two subtasks: (i)
attribute-based representation learning; (ii) interaction-based representation
learning. The first subtask learns the feature representations for both users
and POIs, capturing attributes directly from their profiles. The second subtask
incorporates user-POI interactions into the model. Additionally, MPR can
provide insights into why certain recommendations are being made to a user
based on three types of hints: user-aspect, POI-aspect, and interaction-aspect.
We empirically validate our approach using two real-life datasets, and show
promising performance improvements over several state-of-the-art methods
A Survey on Point-of-Interest Recommendations Leveraging Heterogeneous Data
Tourism is an important application domain for recommender systems. In this
domain, recommender systems are for example tasked with providing personalized
recommendations for transportation, accommodation, points-of-interest (POIs),
or tourism services. Among these tasks, in particular the problem of
recommending POIs that are of likely interest to individual tourists has gained
growing attention in recent years. Providing POI recommendations to tourists
\emph{during their trip} can however be especially challenging due to the
variability of the users' context. With the rapid development of the Web and
today's multitude of online services, vast amounts of data from various sources
have become available, and these heterogeneous data sources represent a huge
potential to better address the challenges of in-trip POI recommendation
problems. In this work, we provide a comprehensive survey of published research
on POI recommendation between 2017 and 2022 from the perspective of
heterogeneous data sources. Specifically, we investigate which types of data
are used in the literature and which technical approaches and evaluation
methods are predominant. Among other aspects, we find that today's research
works often focus on a narrow range of data sources, leaving great potential
for future works that better utilize heterogeneous data sources and diverse
data types for improved in-trip recommendations.Comment: 35 pages, 19 figure
A survey of context-aware recommendation schemes in event-based social networks
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. In recent years, Event-based social network (EBSN) applications, such as Meetup and DoubanEvent, have received popularity and rapid growth. They provide convenient online platforms for users to create, publish, and organize social events, which will be held in physical places. Additionally, they not only support typical online social networking facilities (e.g., sharing comments and photos), but also promote face-to-face offline social interactions. To provide better service for users, Context-Aware Recommender Systems (CARS) in EBSNs have recently been singled out as a fascinating area of research. CARS in EBSNs provide the suitable recommendation to target users by incorporating the contextual factors into the recommendation process. This paper provides an overview on the development of CARS in EBSNs. We begin by illustrating the concept of the term context and the paradigms of conventional context-aware recommendation process. Subsequently, we introduce the formal definition of an EBSN, the characteristics of EBSNs, the challenges that are faced by CARS in EBSNs, and the implementation process of CARS in EBSNs. We also investigate which contextual factors are considered and how they are represented in the recommendation process. Next, we focus on the state-of-the-art computational techniques regarding CARS in EBSNs. We also overview the datasets and evaluation metrics for evaluation in this research area, and discuss the applications of context-aware recommendation in EBSNs. Finally, we point out research opportunities for the research community
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