We consider running multiple instances of multi-armed bandit (MAB) problems in parallel. A main motivation for this study are online recommendation systems, in which each of $N$ users is associated with a MAB problem and the goal is to exploit users' similarity in order to learn users' preferences to $K$ items more efficiently. We consider the adversarial MAB setting, whereby an adversary is free to choose which user and which loss to present to the learner during the learning process. Users are in a social network and the learner is aided by a-priori knowledge of the strengths of the social links between all pairs of users. It is assumed that if the social link between two users is strong then they tend to share the same action. The regret is measured relative to an arbitrary function which maps users to actions. The smoothness of the function is captured by a resistance-based dispersion measure $\Psi$. We present two learning algorithms, GABA-I and GABA-II, which exploit the network structure to bias towards functions of low $\Psi$ values.

We consider running multiple instances of multi-armed bandit (MAB) problems in parallel. A main motivation for this study are online recommendation systems, in which each of N users is associated with a MAB problem and the goal is to exploit users' similarity in order to learn users' preferences to K items more efficiently. We consider the adversarial MAB setting, whereby an adversary is free to choose which user and which loss to present to the learner during the learning process. Users are in a social network and the learner is aided by a-priori knowledge of the strengths of the social links between all pairs of users. It is assumed that if the social link between two users is strong then they tend to share the same action. The regret is measured relative to an arbitrary function which maps users to actions.

It's by now folklore that to understand the activity pattern of a user in an online social network (OSN) platform, one needs to look at his friends or the ones he follows. The common perception is that these friends exert influence on the user, effecting his decision whether to re-share content or not. Hinging upon this intuition, a variety of models were developed to predict how information propagates in OSN, similar to the way infection spreads in the population. In this paper, we revisit this world view and arrive at new conclusions. Given a set of users $V$, we study the task of predicting whether a user $u \in V$ will re-share content by some $v \in V$ at the following time window given the activity of all the users in $V$ in the previous time window. We design several algorithms for this task, ranging from a simple greedy algorithm that only learns $u$'s conditional probability distribution, ignoring the rest of $V$, to a convolutional neural network-based algorithm that receives the activity of all of $V$, but does not receive explicitly the social link structure. We tested our algorithms on four datasets that we collected from Twitter, each revolving around a different popular topic in 2020. The best performance, average F1-score of 0.86 over the four datasets, was achieved by the convolutional neural network. The simple, social-link ignorant, algorithm achieved an average F1-score of 0.78.

Complete Video Series on "Hands on Artificial Intelligence, Machine Learning & Deep Learning using TensorFlow, Keras and Python" I am Gulshan Yadav. An Embedded Systems Development professional with nearly 13 of years R&D experience in design & development of Embedded products in Automotive, IOT and AI domain. About this Video: -------------------------- This video will explain 1. What is Perceptron / Artificial Neuron 2. Basic Building Blocks of Perceptron 3. How Pereptron works? 4. Why Bias is used in Perceptron and Artificial Neural Networks Social Links: Twitter: https://twitter.com/techopcode

Complete Video Series on "Hands on Artificial Intelligence, Machine Learning & Deep Learning using TensorFlow, Keras and Python" I am Gulshan Yadav. An Embedded Systems Development professional with nearly 13 of years R&D experience in design & development of Embedded products in Automotive, IOT and AI domain. About this Video: -------------------------- This video will explain you on the reasons behind why Deep Neural Networks or Deep Learning is so much and is in high Demand Now? Social Links: Twitter: https://twitter.com/techopcode

Complete Video Series on "Hands on Artificial Intelligence, Machine Learning & Deep Learning using TensorFlow, Keras and Python" I am Gulshan Yadav. An Embedded Systems Development professional with nearly 13 of years R&D experience in design & development of Embedded products in Automotive, IOT and AI domain. About this Video: -------------------------- This video will explain you on how to start with Deep Learning and Deep Neural Networks using TensorFlow. Using this video I have tried to create your interest and passion in learning deep neural networks by visualizing the network and layers. This video will also help you in learning how to effectively train the model with great accuracy because training a deep learning model with maximum accuracy is an art in itself.

Complete Video Series on "Hands on Artificial Intelligence, Machine Learning & Deep Learning using TensorFlow, Keras and Python" I am Gulshan Yadav. An Embedded Systems Development professional with nearly 13 of years R&D experience in design & development of Embedded products in Automotive, IOT and AI domain. About this Video: -------------------------- This video will explain you on the different steps involved in creating a simple neural networks deep learning model using TensorFlow 2.0, Keras & Python. This will also gives you a hand on experience on implementing a deep learning model in Google colab.

To enjoy more social network services, users nowadays are usually involved in multiple online social media sites at the same time. Across these social networks, users can be connected by both intra-network links (i.e., social links) and inter-network links (i.e., anchor links) simultaneously. In this paper, we want to predict the formation of social links among users in the target network as well as anchor links aligning the target network with other external social networks. The problem is formally defined as the “collective link identification” problem. To solve the collective link identification problem, a unified link prediction framework, CLF (Collective Link Fusion) is proposed in this paper, which consists of two phases: step (1) collective link prediction of anchor and social links, and step (2) propagation of predicted links across the partially aligned “probabilistic networks” with collective random walk. Extensive experiments conducted on two real-world partially aligned networks demonstrate that CLF can perform very well in predicting social and anchor links concurrently.

The popularity of the Web has allowed individuals to communicate and interact with each other on a global scale: people connect both to close friends and acquaintances, creating ties that can bridge otherwise separated groups of people. Recent evidence suggests that spatial distance is still affecting social links established on online platforms, with online ties preferentially connecting closer people. In this work we study the relationships between interaction strength, spatial distance and structural position of ties between members of a large-scale online social networking platform, Tuenti. We discover that ties in highly connected social groups tend to span shorter distances than connections bridging together otherwise separated portions of the network. We also find that such bridging connections have lower social interaction levels than ties within the inner core of the network and ties connecting to its periphery. Our results suggest that spatial constraints on online social networks are intimately connected to structural network properties, with important consequences for information diffusion.

The spatial structure of large-scale online social networks has been largely unaccessible due to the lack of available and accurate data about people’s location. However, with the recent surging popularity of location-based social services, data about the geographic position of users have been available for the first time, together with their online social connections. In this work we present a comprehensive study of the spatial properties of the social networks arising among users of three main popular online location-based services. We observe robust universal features across them: while all networks exhibit about 40% of links below 100 km, we further discover strong heterogeneity across users, with different characteristic spatial lengths of interaction across both their social ties and social triads. We provide evidence that mechanisms akin to gravity models may influence how these social connections are created over space. Our results constitute the first large-scale study to unravel the socio-spatial properties of online location-based social networks.