Efficient Bayesian Learning in Social Networks with Gaussian Estimators

We consider a group of Bayesian agents who try to estimate a state of the world $\theta$ through interaction on a social network. Each agent $v$ initially receives a private measurement of $\theta$: a number $S_v$ picked from a Gaussian distribution with mean $\theta$ and standard deviation one. Then, in each discrete time iteration, each reveals its estimate of $\theta$ to its neighbors, and, observing its neighbors' actions, updates its belief using Bayes' Law. This process aggregates information efficiently, in the sense that all the agents converge to the belief that they would have, had they access to all the private measurements. We show that this process is computationally efficient, so that each agent's calculation can be easily carried out. We also show that on any graph the process converges after at most $2N \cdot D$ steps, where $N$ is the number of agents and $D$ is the diameter of the network. Finally, we show that on trees and on distance transitive-graphs the process converges after $D$ steps, and that it preserves privacy, so that agents learn very little about the private signal of most other agents, despite the efficient aggregation of information. Our results extend those in an unpublished manuscript of the first and last authors.Comment: Added coauthor. Added proofs for fast convergence on trees and distance transitive graphs. Also, now analyzing a notion of privac

Beyond Heroes & Role Models: Using Biographies to Develop Young Change Agents

Reading, writing, and discussing biographies provide unique opportunities for teachers and students. Critical thinking can be developed through questioning, predicting, and analyzing various biographical mediums--texts, photographs and illustrations, book reviews, websites, films, news articles, etc.--to learn more about an individual\u27s life experiences and choices. Decision making skills can be enhanced when students juxtapose their perceptions of heroes and role models to that of a change agent, even considering how their own life experiences and choices may be contributing to larger actions of change. In this article, the authors discuss six biographies that could be used with young people in the elementary classroom to study change agents. The authors carefully selected and organized their literary choices into four categories: (1) familiar historical figures, (2) familiar living persons, (3) less familiar figures, and finally (4) students and teachers themselves--because they can act as change agents today on a local and personal level

Feedback in Tournaments under Commitment Problems: The-ory and Experimental Evidence

In this paper, we analyze a principal's optimal feedback policy in tournaments. We close a gap in the literature by assuming the principal to be unable to commit to a certain policy at the beginning of the tournament. Our analysis shows that in equilibrium the principal reveals in-termediate information regarding the agents’ previous performances if these performances are not too different. Moreover, we investigate a situation where the principal is not able to credi-bly communicate her information. Having presented our formal analysis, we test these results using data from laboratory experiments. The experimental findings provide some support for the model

A review on massive e-learning (MOOC) design, delivery and assessment

MOOCs or Massive Online Open Courses based on Open Educational Resources (OER) might be one of the most versatile ways to offer access to quality education, especially for those residing in far or disadvantaged areas. This article analyzes the state of the art on MOOCs, exploring open research questions and setting interesting topics and goals for further research. Finally, it proposes a framework that includes the use of software agents with the aim to improve and personalize management, delivery, efficiency and evaluation of massive online courses on an individual level basis.Peer ReviewedPostprint (author's final draft

Analyzing Input and Output Representations for Speech-Driven Gesture Generation

This paper presents a novel framework for automatic speech-driven gesture generation, applicable to human-agent interaction including both virtual agents and robots. Specifically, we extend recent deep-learning-based, data-driven methods for speech-driven gesture generation by incorporating representation learning. Our model takes speech as input and produces gestures as output, in the form of a sequence of 3D coordinates. Our approach consists of two steps. First, we learn a lower-dimensional representation of human motion using a denoising autoencoder neural network, consisting of a motion encoder MotionE and a motion decoder MotionD. The learned representation preserves the most important aspects of the human pose variation while removing less relevant variation. Second, we train a novel encoder network SpeechE to map from speech to a corresponding motion representation with reduced dimensionality. At test time, the speech encoder and the motion decoder networks are combined: SpeechE predicts motion representations based on a given speech signal and MotionD then decodes these representations to produce motion sequences. We evaluate different representation sizes in order to find the most effective dimensionality for the representation. We also evaluate the effects of using different speech features as input to the model. We find that mel-frequency cepstral coefficients (MFCCs), alone or combined with prosodic features, perform the best. The results of a subsequent user study confirm the benefits of the representation learning.Comment: Accepted at IVA '19. Shorter version published at AAMAS '19. The code is available at https://github.com/GestureGeneration/Speech_driven_gesture_generation_with_autoencode