A Causal And-Or Graph Model for Visibility Fluent Reasoning in Tracking Interacting Objects

Tracking humans that are interacting with the other subjects or environment remains unsolved in visual tracking, because the visibility of the human of interests in videos is unknown and might vary over time. In particular, it is still difficult for state-of-the-art human trackers to recover complete human trajectories in crowded scenes with frequent human interactions. In this work, we consider the visibility status of a subject as a fluent variable, whose change is mostly attributed to the subject's interaction with the surrounding, e.g., crossing behind another object, entering a building, or getting into a vehicle, etc. We introduce a Causal And-Or Graph (C-AOG) to represent the causal-effect relations between an object's visibility fluent and its activities, and develop a probabilistic graph model to jointly reason the visibility fluent change (e.g., from visible to invisible) and track humans in videos. We formulate this joint task as an iterative search of a feasible causal graph structure that enables fast search algorithm, e.g., dynamic programming method. We apply the proposed method on challenging video sequences to evaluate its capabilities of estimating visibility fluent changes of subjects and tracking subjects of interests over time. Results with comparisons demonstrate that our method outperforms the alternative trackers and can recover complete trajectories of humans in complicated scenarios with frequent human interactions.Comment: accepted by CVPR 201

Tracking Streamer Blobs Into the Heliosphere

In this paper, we use coronal and heliospheric images from the STEREO spacecraft to track streamer blobs into the heliosphere and to observe them being swept up and compressed by the fast wind from low-latitude coronal holes. From an analysis of their elongation/time tracks, we discover a 'locus of enhanced visibility' where neighboring blobs pass each other along the line of sight and their corotating spiral is seen edge on. The detailed shape of this locus accounts for a variety of east-west asymmetries and allows us to recognize the spiral of blobs by its signatures in the STEREO images: In the eastern view from STEREO-A, the leading edge of the spiral is visible as a moving wavefront where foreground ejections overtake background ejections against the sky and then fade. In the western view from STEREO-B, the leading edge is only visible close to the Sun-spacecraft line where the radial path of ejections nearly coincides with the line of sight. In this case, we can track large-scale waves continuously back to the lower corona and see that they originate as face-on blobs.Comment: 15 pages plus 11 figures; figure 6 shows the 'locus of enhanced visibility', which we call 'the bean'. (accepted by ApJ 4/02/2010

Using data from connected thermostats to track large power outages in the United States

The detection of power outages is an essential activity for electric utilities. A large, national dataset of Internet-connected thermostats was used to explore and illustrate the ability of Internet-connected devices to geospatially track outages caused by hurricanes and other major weather events. The method was applied to nine major outage events, including hurricanes and windstorms. In one event, Hurricane Irma, a network of about 1000 thermostats provided quantitatively similar results to detailed utility data with respect to the number of homes without power and identification of the most severely affected regions. The method generated regionally uniform outage data that would give emergency authorities additional visibility into the scope and magnitude of outages. The network of thermostat-sensors also made it possible to calculate a higher resolution version of outage duration (or SAIDI) at a level of customer-level visibility that was not previously available

Here Comes the Sunburst: Measuring and Visualizing Scholarly Impact

Our ARL institution partnered with a new service (PlumX) to track, measure, and visualize faculty scholarly impact. In a pilot project, both traditional and emerging measures of scholarly impact were collected for 32 researchers. The presenters will chronicle the data management and enhancements applied, including utilizing content from our institutional repository, importing and enriching metadata, and using an intranet to organize work and collaborate with colleagues. Results will assist faculty and those who work with them to identify strengths and weaknesses of scholarly impact and where to focus efforts to increase research visibility

Ensuring the visibility and traceability of items through logistics chain of automotive industry based on AutoEPCNet Usage

Traceability in logistics is the capability of the participants to trace the products throughout the supply chain by means of either the product and/or container identifiers in a forward and/or backward direction. In today's competitive economic environment, traceability is a key concept related to all products and all types of supply chains. The goal of this paper is to describe development of application that enables to create and share information about the physical movement and status of products as they travel throughout the supply chain. The main purpose of this paper is to describe the development of RFID based track and trace system for ensuring the visibility and traceability of items in logistics chain especially in automotive industry. The proposed solution is based on EPCglobal Network Architecture

Multipath Correlation Interference and Controlled-NOT Gate Simulation with a Thermal Source

We theoretically demonstrate a counter-intuitive phenomenon in optical interferometry with a thermal source: the emergence of second-order interference between two pairs of correlated optical paths even if the time delay imprinted by each path in one pair with respect to each path in the other pair is much larger than the source coherence time. This fundamental effect could be useful for experimental simulations of small-scale quantum circuits and of $100\%$-visibility correlations typical of entangled states of a large number of qubits, with possible applications in high-precision metrology and imaging. As an example, we demonstrate the polarization-encoded simulation of the operation of the quantum logic gate known as controlled-NOT gate.Comment: New Journal of Physics (Fast Track Communication, in press, 6 pages, 3 figures

Space-Enhanced Solar Power for Equatorial Regions

This paper examines the concept of solar mirrors in a Earth orbit to provide solar farms with additional solar power during the hours of darkness. The design of the orbit is key for the purposes of the mission: the mirror needs continuous access to the Sun and the solar farm simultaneously. Therefore, orbits with high-eccentricity will be considered to increase the visibility time. Also, since the most convenient locations for solar power farms are about the equator, a suitable orbit should have a low inclination. This issue can be addressed through the concept of anti-heliotropic orbits that exploits mainly solar radiation pressure perturbations to generate highly-eccentric equatorial orbits able to maintain the orientation with respect to the Sun. The considered configuration consists in two space mirrors in a flower constellation rotating with the Earth to deliver a repeat ground track

PAMPC: Perception-Aware Model Predictive Control for Quadrotors

We present the first perception-aware model predictive control framework for quadrotors that unifies control and planning with respect to action and perception objectives. Our framework leverages numerical optimization to compute trajectories that satisfy the system dynamics and require control inputs within the limits of the platform. Simultaneously, it optimizes perception objectives for robust and reliable sens- ing by maximizing the visibility of a point of interest and minimizing its velocity in the image plane. Considering both perception and action objectives for motion planning and control is challenging due to the possible conflicts arising from their respective requirements. For example, for a quadrotor to track a reference trajectory, it needs to rotate to align its thrust with the direction of the desired acceleration. However, the perception objective might require to minimize such rotation to maximize the visibility of a point of interest. A model-based optimization framework, able to consider both perception and action objectives and couple them through the system dynamics, is therefore necessary. Our perception-aware model predictive control framework works in a receding-horizon fashion by iteratively solving a non-linear optimization problem. It is capable of running in real-time, fully onboard our lightweight, small-scale quadrotor using a low-power ARM computer, to- gether with a visual-inertial odometry pipeline. We validate our approach in experiments demonstrating (I) the contradiction between perception and action objectives, and (II) improved behavior in extremely challenging lighting conditions