Personal Assistant Systems
STELLAR: Spatial-Temporal Latent Ranking for Successive Point-of-Interest Recommendation
Zhao, Shenglin (The Chinese University of Hong Kong) | Zhao, Tong (The Chinese University of Hong Kong) | Yang, Haiqin (The Chinese University of Hong Kong) | Lyu, Michael R. (The Chinese University of Hong Kong) | King, Irwin (The Chinese University of Hong Kong)
Successive point-of-interest (POI) recommendation in location-based social networks (LBSNs) becomes a significant task since it helps users to navigate a number of candidate POIs and provides the best POI recommendations based on usersโ most recent check-in knowledge. However, all existing methods for successive POI recommendation only focus on modeling the correlation between POIs based on usersโ check-in sequences, but ignore an important fact that successive POI recommendation is a time-subtle recommendation task. In fact, even with the same previous check-in information, users would prefer different successive POIs at different time. To capture the impact of time on successive POI recommendation, in this paper, we propose a spatial-temporal latent ranking (STELLAR) method to explicitly model the interactions among user, POI, and time. In particular, the proposed STELLAR model is built upon a ranking-based pairwise tensor factorization framework with a fine-grained modeling of user-POI, POI-time, and POI-POI interactions for successive POI recommendation. Moreover, we propose a new interval-aware weight utility function to differentiate successive check-insโ correlations, which breaks the time interval constraint in prior work. Evaluations on two real-world datasets demonstrate that the STELLAR model outperforms state-of-the-art successive POI recommendation model about 20% in Precision@5 and Recall@5.
Recommendation with Social Dimensions
Tang, Jiliang (Yahoo Labs) | Wang, Suhang (Arizona State University) | Hu, Xia (Texas A&M University) | Yin, Dawei (Yahoo Labs) | Bi, Yingzhou (Guangxi Teachers Education University) | Chang, Yi (Yahoo Labs) | Liu, Huan (Arizona State University)
The pervasive presence of social media greatly enriches online users' social activities, resulting in abundant social relations. Social relations provide an independent source for recommendation, bringing about new opportunities for recommender systems. Exploiting social relations to improve recommendation performance attracts a great amount of attention in recent years. Most existing social recommender systems treat social relations homogeneously and make use of direct connections (or strong dependency connections). However, connections in online social networks are intrinsically heterogeneous and are a composite of various relations. While connected users in online social networks form groups, and users in a group share similar interests, weak dependency connections are established among these users when they are not directly connected. In this paper, we investigate how to exploit the heterogeneity of social relations and weak dependency connections for recommendation. In particular, we employ social dimensions to simultaneously capture heterogeneity of social relations and weak dependency connections, and provide principled ways to model social dimensions, and propose a recommendation framework SoDimRec which incorporates heterogeneity of social relations and weak dependency connections based on social dimensions. Experimental results on real-world data sets demonstrate the effectiveness of the proposed framework. We conduct further experiments to understand the important role of social dimensions in the proposed framework.
On the Effectiveness of Linear Models for One-Class Collaborative Filtering
Sedhain, Suvash (Australian National University) | Menon, Aditya Krishna (Australian National University and NICTA) | Sanner, Scott (Oregon State University and Australian National University) | Braziunas, Darius (Rakuten Kobo Inc)
In many personalised recommendation problems, there are examples of items users prefer or like, but no examples of items they dislike. A state-of-the-art method for such implicit feedback, or one-class collaborative filtering (OC-CF), problems is SLIM, which makes recommendations based on a learned item-item similarity matrix. While SLIM has been shown to perform well on implicit feedback tasks, we argue that it is hindered by two limitations: first, it does not produce user-personalised predictions, which hampers recommendation performance; second, it involves solving a constrained optimisation problem, which impedes fast training. In this paper, we propose LRec, a variant of SLIM that overcomes these limitations without sacrificing any of SLIM's strengths.At its core, LRec employs linear logistic regression; despite this simplicity, LRec consistently and significantly outperforms all existing methods on a range of datasets. Our results thus illustrate that the OC-CF problem can be effectively tackled via linear classification models.
Top-N Recommender System via Matrix Completion
Kang, Zhao (Southern Illinois University Carbondale ) | Peng, Chong (Southern Illinois University Carbondale) | Cheng, Qiang (Southern Illinois University Carbondale)
Top-N recommender systems have been investigated widely both in industry and academia. However, the recommendation quality is far from satisfactory. In this paper, we propose a simple yet promising algorithm. We fill the user-item matrix based on a low-rank assumption and simultaneously keep the original information. To do that, a nonconvex rank relaxation rather than the nuclear norm is adopted to provide a better rank approximation and an efficient optimization strategy is designed. A comprehensive set of experiments on real datasets demonstrates that our method pushes the accuracy of Top-N recommendation to a new level.
VBPR: Visual Bayesian Personalized Ranking from Implicit Feedback
He, Ruining (University of California, San Diego) | McAuley, Julian ( University of California, San Diego )
Modern recommender systems model people and items by discovering or `teasing apart' the underlying dimensions that encode the properties of items and users' preferences toward them. Critically, such dimensions are uncovered based on user feedback, often in implicit form (such as purchase histories, browsing logs, etc.); in addition, some recommender systems make use of side information, such as product attributes, temporal information, or review text.However one important feature that is typically ignored by existing personalized recommendation and ranking methods is the visual appearance of the items being considered. In this paper we propose a scalable factorization model to incorporate visual signals into predictors of people's opinions, which we apply to a selection of large, real-world datasets. We make use of visual features extracted from product images using (pre-trained) deep networks, on top of which we learn an additional layer that uncovers the visual dimensions that best explain the variation in people's feedback. This not only leads to significantly more accurate personalized ranking methods, but also helps to alleviate cold start issues, and qualitatively to analyze the visual dimensions that influence people's opinions.
Inferring a Personalized Next Point-of-Interest Recommendation Model with Latent Behavior Patterns
He, Jing (Beijing Institute of Technology) | Li, Xin (Beijing Institute of Technology) | Liao, Lejian (Beijing Institute of Technology) | Song, Dandan (Beijing Institute of Technology) | Cheung, William K. (Hong Kong Baptist University)
In this paper, we address the problem of personalized next Point-of-interest (POI) recommendation which has become an important and very challenging task in location-based social networks (LBSNs), but not well studied yet. With the conjecture that, under different contextual scenario, human exhibits distinct mobility patterns, we attempt here to jointly model the next POI recommendation under the influence of user's latent behavior pattern. We propose to adopt a third-rank tensor to model the successive check-in behaviors. By incorporating softmax function to fuse the personalized Markov chain with latent pattern, we furnish a Bayesian Personalized Ranking (BPR) approach and derive the optimization criterion accordingly. Expectation Maximization (EM) is then used to estimate the model parameters. Extensive experiments on two large-scale LBSNs datasets demonstrate the significant improvements of our model over several state-of-the-art methods.
Little Is Much: Bridging Cross-Platform Behaviors through Overlapped Crowds
Jiang, Meng (Tsinghua University) | Cui, Peng (Tsinghua University) | Yuan, Nicholas Jing (Microsoft Research Asia) | Xie, Xing (Microsoft Research Asia) | Yang, Shiqiang (Tsinghua University)
People often use multiple platforms to fulfill their different information needs. With the ultimate goal of serving people intelligently, a fundamental way is to get comprehensive understanding about user needs. How to organically integrate and bridge cross-platform information in a human-centric way is important. Existing transfer learning assumes either fully-overlapped or non-overlapped among the users. However, the real case is the users of different platforms are partially overlapped. The number of overlapped users is often small and the explicitly known overlapped users is even less due to the lacking of unified ID for a user across different platforms. In this paper, we propose a novel semi-supervised transfer learning method to address the problem of cross-platform behavior prediction, called XPTrans. To alleviate the sparsity issue, it fully exploits the small number of overlapped crowds to optimally bridge a user's behaviors in different platforms. Extensive experiments across two real social networks show that XPTrans significantly outperforms the state-of-the-art. We demonstrate that by fully exploiting 26% overlapped users, XPTrans can predict the behaviors of non-overlapped users with the same accuracy as overlapped users, which means the small overlapped crowds can successfully bridge the information across different platforms.
Atomic 212 'dating droid' uses iPad and Skype to help those on first dates
Impressive dinners and high bar tabs could soon be things of the past with a new futuristic way of dating. Lucy Kelly, who used a droid to keep her place in line at an Apple store last year, wants to now use the telepresence robot to fill in the voids of intimacy that are often linked to online dating. Users could sit at home while the robot joins their date miles away at a coffee shop-- adding a more personal element to an inexpensive first encounter. Lucy Kelly, who used a droid to keep her place in line at an Apple store last year, wants to use a telepresence robot to fill in the voids of intimacy that are often linked to online dating.The robot can be controlled from anywhere there is internet, so users can have a conversation with a potential suitor miles away The telepresence robot, created by Double Robotics, has lateral stability control that lets the device move with ease across different surfaces and around obstacles. Its power drive enables it to go up to 80 percent faster than normal driving speed and is controlled by holding down the shift key on the keyboard.
Siri May Have Just Spilled an Apple Secret
As it turns out, Siri isn't good at keeping secrets. On Monday, multiple users on Twitter and Apple news tracking site 9to5Mac reported that Apple's personal assistant is so excited for the company's next developer conference, she is revealing the official dates before the tech giant itself. The official WWDC website still reflects the logo and information surrounding WWDC 2015. If Siri is correct, Apple is planning to hold its 2016 Worldwide Developer Conference from June 13 to June 17 in San Francisco, Calif. Past developer events have also been held in San Francisco at the Moscone West Convention Center.
Apple's 2016 WWDC event set to begin on June 13
While Apple's annual iPhone unveiling is undoubtedly the company's biggest event each and every year, WWDC is clearly a close second. As the event where Apple showcases its latest advancements in user design and iOS and OS X technologies, Apple's annual worldwide developers conference typically provides us with a fascinating sneak peak at the future of mobile and desktop computing. This year, WWDC is slated to take place from June 13 and June 17 in San Francisco at the Moscone West convention center. Interestingly enough, word of Apple's WWDC schedule this year was initially leaked by Siri. Earlier today, a number of sites noted that when you ask Siri when WWDC is, Apple's intelligent personal assistant responds with the following: The Worldwide Developers Conference (WWDC) will be held June 13 through June 17 in San Francisco.