874 research outputs found

    A solution of the Gaussian optimizer conjecture

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    The long-standing conjectures of the optimality of Gaussian inputs for Gaussian channel and Gaussian additivity are solved for a broad class of covariant or contravariant Bosonic Gaussian channels (which includes in particular thermal, additive classical noise, and amplifier channels) restricting to the class of states with finite second moments. We show that the vacuum is the input state which minimizes the entropy at the output of such channels. This allows us to show also that the classical capacity of these channels (under the input energy constraint) is additive and is achieved by Gaussian encodings.Comment: 24 pages, no figures (minor typos corrected

    MIRIAM: A Multimodal Chat-Based Interface for Autonomous Systems

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    We present MIRIAM (Multimodal Intelligent inteRactIon for Autonomous systeMs), a multimodal interface to support situation awareness of autonomous vehicles through chat-based interaction. The user is able to chat about the vehicle's plan, objectives, previous activities and mission progress. The system is mixed initiative in that it pro-actively sends messages about key events, such as fault warnings. We will demonstrate MIRIAM using SeeByte's SeeTrack command and control interface and Neptune autonomy simulator.Comment: 2 pages, ICMI'17, 19th ACM International Conference on Multimodal Interaction, November 13-17 2017, Glasgow, U

    The longitudinal negative impact of early stressful events on emotional and physical well-being: The buffering role of cardiac vagal development

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    Early stressful events negatively affect emotional and physical well-being. Cardiac vagal tone (CVT), which is associated with better emotional and physical well-being, usually gradually increase in early childhood. Nonetheless, children's CVT developmental trajectories are greatly variable, such that CVT can increase or decrease across the years. The present study examines the longitudinal effects of early stressful events and the role of 4 years CVT developmental trajectory on children's emotional and physical well-being. Forty-two 4-year-old children were enrolled. Number of stressful events and resting electrocardiogram (ECG) were collected at T1. ECG was registered again after one (T2), two (T3) and three (T4) years. Children's emotional and physical well-being were assessed at T4 through the Child Health and Illness Profile – Child Edition (CHIP–CE). CVT development was calculated as the angular coefficient, reflecting the developmental trajectory of CVT across the four timepoints. Results yielded that higher experienced stressful events predicted poorer emotional and physical well-being after 4 years. The interaction between the number of stressful events and CVT development emerged on physical well-being. Early stressful events negatively affect long-term children's emotional and physical well-being while a positive CVT development seems to mitigate the negative effects of early stressful events on physical well-being

    A case study of management shortcomings: Lessons from the B737-Max aviation accidents

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    This case study looked into the shortcomings in of Boeing’s upper management in the engineering and fielding of the B737-Max. Under pressure to build a plane with identical flying characteristics to the existing B737 family, Boeing included modifications but purposely concealed those changes from regulators and pilots. This decision resulted in fatal accidents in 2018 and 2019 and caused the deaths of 346 passengers. Unlike previous aviation accidents, these mishaps were entirely preventable and a direct result of Boeing’s organizational failures and management shortcomings. This case study analyzed the behavior, decision making process, and reasons which led Boeing to push for the certification of the B737-Max despite these known flaws in the design. Additionally, this poster studied the consequences and punitive actions that followed the investigation of the two crashes. The poster concludes by offering recommendations to the aviation industry on how accidents such as this can be avoided in the future

    Closed timelike curves via post-selection: theory and experimental demonstration

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    Closed timelike curves (CTCs) are trajectories in spacetime that effectively travel backwards in time: a test particle following a CTC can in principle interact with its former self in the past. CTCs appear in many solutions of Einstein's field equations and any future quantum version of general relativity will have to reconcile them with the requirements of quantum mechanics and of quantum field theory. A widely accepted quantum theory of CTCs was proposed by Deutsch. Here we explore an alternative quantum formulation of CTCs and show that it is physically inequivalent to Deutsch's. Because it is based on combining quantum teleportation with post-selection, the predictions/retrodictions of our theory are experimentally testable: we report the results of an experiment demonstrating our theory's resolution of the well-known `grandfather paradox.Comment: 5 pages, 4 figure

    Explain Yourself: A Natural Language Interface for Scrutable Autonomous Robots

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    Autonomous systems in remote locations have a high degree of autonomy and there is a need to explain what they are doing and why in order to increase transparency and maintain trust. Here, we describe a natural language chat interface that enables vehicle behaviour to be queried by the user. We obtain an interpretable model of autonomy through having an expert 'speak out-loud' and provide explanations during a mission. This approach is agnostic to the type of autonomy model and as expert and operator are from the same user-group, we predict that these explanations will align well with the operator's mental model, increase transparency and assist with operator training.Comment: 2 pages. Peer reviewed position paper accepted in the Explainable Robotic Systems Workshop, ACM Human-Robot Interaction conference, March 2018, Chicago, IL US
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