Simultaneous Optical Flow and Segmentation (SOFAS) using Dynamic Vision Sensor

We present an algorithm (SOFAS) to estimate the optical flow of events generated by a dynamic vision sensor (DVS). Where traditional cameras produce frames at a fixed rate, DVSs produce asynchronous events in response to intensity changes with a high temporal resolution. Our algorithm uses the fact that events are generated by edges in the scene to not only estimate the optical flow but also to simultaneously segment the image into objects which are travelling at the same velocity. This way it is able to avoid the aperture problem which affects other implementations such as Lucas-Kanade. Finally, we show that SOFAS produces more accurate results than traditional optic flow algorithms

Event-Based Motion Segmentation by Motion Compensation

In contrast to traditional cameras, whose pixels have a common exposure time, event-based cameras are novel bio-inspired sensors whose pixels work independently and asynchronously output intensity changes (called "events"), with microsecond resolution. Since events are caused by the apparent motion of objects, event-based cameras sample visual information based on the scene dynamics and are, therefore, a more natural fit than traditional cameras to acquire motion, especially at high speeds, where traditional cameras suffer from motion blur. However, distinguishing between events caused by different moving objects and by the camera's ego-motion is a challenging task. We present the first per-event segmentation method for splitting a scene into independently moving objects. Our method jointly estimates the event-object associations (i.e., segmentation) and the motion parameters of the objects (or the background) by maximization of an objective function, which builds upon recent results on event-based motion-compensation. We provide a thorough evaluation of our method on a public dataset, outperforming the state-of-the-art by as much as 10%. We also show the first quantitative evaluation of a segmentation algorithm for event cameras, yielding around 90% accuracy at 4 pixels relative displacement.Comment: When viewed in Acrobat Reader, several of the figures animate. Video: https://youtu.be/0q6ap_OSBA

Identifying Feasible Interventions to Prevent Long-Term Health Consequences of Psychotropic Medications Prescribed to Children at the Baird School

Introduction: •Many children with behavioral needs struggle in traditional classroom settings. Children receive help through specialized educational institutions, pharmacotherapy, and psychiatric counseling. •While substantial information exists about drug indications and side effects, there is little literature documenting the barriers caregivers face in addressing side effects •Our group conducted a literature review to identify the side effects and associated comorbidities of the six most frequently prescribed psychotropic drugs at the Baird School. •We designed a survey to assess the caregivers’ resources and barriers to minimizing these side effects, and then offered a collection of feasible recommendations.https://scholarworks.uvm.edu/comphp_gallery/1049/thumbnail.jp

Oxygenated Aromatic Compounds are Important Precursors of Secondary Organic Aerosol in Biomass Burning Emissions

Biomass burning is the largest combustion-related source of volatile organic compounds (VOCs) to the atmosphere. We describe the development of a state-of-the-science model to simulate the photochemical formation of secondary organic aerosol (SOA) from biomass-burning emissions observed in dry (RH <20%) environmental chamber experiments. The modeling is supported by (i) new oxidation chamber measurements, (ii) detailed concurrent measurements of SOA precursors in biomass-burning emissions, and (iii) development of SOA parameters for heterocyclic and oxygenated aromatic compounds based on historical chamber experiments. We find that oxygenated aromatic compounds, including phenols and methoxyphenols, account for slightly less than 60% of the SOA formed and help our model explain the variability in the organic aerosol mass (R² = 0.68) and O/C (R² = 0.69) enhancement ratios observed across 11 chamber experiments. Despite abundant emissions, heterocyclic compounds that included furans contribute to ∼20% of the total SOA. The use of pyrolysis-temperature-based or averaged emission profiles to represent SOA precursors, rather than those specific to each fire, provide similar results to within 20%. Our findings demonstrate the necessity of accounting for oxygenated aromatics from biomass-burning emissions and their SOA formation in chemical mechanisms

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Robotics research is dependent on intelligent, fast, accurate, reliable, and cheap sensors. Sonar sensing can fulfill these requirements. Moreover, sonar physics provides robotics researchers with a natural selection capability for landmark detection in navigation problems. This paper presents a new sonar system that produces accurate measurement and on-the-fly single cycle classification of planes, corners, and edges. The paper shows how double pulse coding of the transmitted pulse can be exploited to simultaneously reject interference and perform classification. On a moving platform, the velocity of the sonar sensor affects range and bearing measurements and is dependent on the target type. These effects are analyzed in the paper. Effects of rotation are also considered. The analytical results derived in the paper for velocity-generated deviations in sonar range and bearing estimates are compared with experimental data. Th