Exact Recovery for a Family of Community-Detection Generative Models

Generative models for networks with communities have been studied extensively for being a fertile ground to establish information-theoretic and computational thresholds. In this paper we propose a new toy model for planted generative models called planted Random Energy Model (REM), inspired by Derrida's REM. For this model we provide the asymptotic behaviour of the probability of error for the maximum likelihood estimator and hence the exact recovery threshold. As an application, we further consider the 2 non-equally sized community Weighted Stochastic Block Model (2-WSBM) on $h$-uniform hypergraphs, that is equivalent to the P-REM on both sides of the spectrum, for high and low edge cardinality $h$. We provide upper and lower bounds for the exact recoverability for any $h$, mapping these problems to the aforementioned P-REM. To the best of our knowledge these are the first consistency results for the 2-WSBM on graphs and on hypergraphs with non-equally sized community

Agenda and emergence : contingent and planned activities in a meeting

The transition between phases of activities is a practical problem which participants in an interaction have to deal with routinely. In meetings, the sequence of phases of activity is often outlined by a written agenda. However, transitions still have to be accomplished by local interactional work of the participants. In a detailed conversation analytic case study based on video-data, it is shown how participants collaboratively accomplish an emergent interactional state of affairs (a break-like activity) which differs widely from the state of affairs which was projected by awritten agenda (the next presentation), although in doing so, the participants still show their continuous orientation to the agenda. The paper argues that the reconstruction of emergent developments in interaction calls for a multimodal analysis of interaction, because the fine-grained multimodal co-ordination of bodily and verbal resources provides for opportunities of sequentially motivated, relevant next actions. These, however, can amount to emergent activity sequences, which may be at odds with the activity types which are projected by an interactional agenda or expected on behalf of some institutional routine

Interweaving Objects, Gestures, and Talk in Context

International audienceIn a large French hospital, a group of professional experts (including physicians and software engineers) are working on the computerization of a blood-transfusion traceability device. By focusing on a particular moment in this slow process of design, we analyze their collaborative practices during a work session. The analysis takes a praxeological and interactionist approach and is inspired by discussions on the role of artifacts in social practices currently developed within various research frameworks in this field: activity theory, distributed cognition, conversation analysis, and actor-network theory. After a brief presentation of the place of objects and artifacts in these ways of approaching action and human cognition, we show how the collective activity analyzed here is generated by the interweaving of discursive, gestural, and artifactual resources

Multimodal participation in simultaneous joint projects. Interpersonal and intrapersonal coordination in paramedic emergency drills

This paper analyses paramedic emergency interaction as multimodal multiactivity. Based on a corpus of video-recordings of emergency drills performed by professional paramedics during advanced training, the focus is on paramedics’ participation in multiple joint projects which become simultaneously relevant. Simultaneity and fast succession of multiactivity does not only characterise work on the team level, but also the work profile of the individual paramedic. Participants have to coordinate their own participation in more than one joint project intrapersonally. In the data studied, three patterns of allocating multimodal resources stood out as routine ways of coordinating participation in two simultaneous projects intrapersonally: 1. Talk and hearing vs. manual action monitored by gaze, 2. Talk and hearing vs. gazing (and pointing), 3. Manual action vs. gaze (and talk and hearing)

Autonomous Construction with Compliant Building Material

In this paper, we develop an autonomous construction system in which a self-contained ground robot builds a protective barrier by means of compliant pockets (i.e., filled bags). We present a stochastic control algorithm based on two biological mechanisms (stigmergy and templates) that takes advantage of compliant pockets for autonomous construction. The control algorithm guides the robot to build the structure without relying on any external motion capture system or external computer. We propose a statistical model to represent the structures built with the compliant pockets, and we provide a set of criteria for assessing the performance of the proposed system. To demonstrate the feasibility of the proposed system, real-robot experiments were carried out. In each experiment, the robot successfully built the structure. The results show the viability of the proposed autonomous construction system

Autonomous construction using scarce resources in unknown environments: Ingredients for an intelligent robotic interaction with the physical world

The goal of creating machines that autonomously perform useful work in a safe, robust and intelligent manner continues to motivate robotics research. Achieving this autonomy requires capabilities for understanding the environment, physically interacting with it, predicting the outcomes of actions and reasoning with this knowledge. Such intelligent physical interaction was at the centre of early robotic investigations and remains an open topic. In this paper, we build on the fruit of decades of research to explore further this question in the context of autonomous construction in unknown environments with scarce resources. Our scenario involves a miniature mobile robot that autonomously maps an environment and uses cubes to bridge ditches and build vertical structures according to high-level goals given by a human. Based on a "real but contrived” experimental design, our results encompass practical insights for future applications that also need to integrate complex behaviours under hardware constraints, and shed light on the broader question of the capabilities required for intelligent physical interaction with the real worl