598 research outputs found

    Target Tracking in Wireless Sensor Networks

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    A Brain-Inspired Multi-Modal Perceptual System for Social Robots: An Experimental Realization

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    We propose a multi-modal perceptual system that is inspired by the inner working of the human brain; in particular, the hierarchical structure of the sensory cortex and the spatial-temporal binding criteria. The system is context independent and can be applied to many on-going problems in social robotics, including but not limited to person recognition, emotion recognition, and multi-modal robot doctor to name a few. The system encapsulates the parallel distributed processing of real-world stimuli through different sensor modalities and encoding them into features vectors which in turn are processed via a number of dedicated processing units (DPUs) through hierarchical paths. DPUs are algorithmic realizations of the cell assemblies in neuroscience. A plausible and realistic perceptual system is presented via the integration of the outputs from these units by spiking neural networks. We will also discuss other components of the system including top-down influences and the integration of information through temporal binding with fading memory and suggest two alternatives to realize these criteria. Finally, we will demonstrate the implementation of this architecture on a hardware platform as a social robot and report experimental studies on the system

    Change blindness: eradication of gestalt strategies

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    Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

    Musical Haptics

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    Haptic Musical Instruments; Haptic Psychophysics; Interface Design and Evaluation; User Experience; Musical Performanc

    Musical Haptics

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    Haptic Musical Instruments; Haptic Psychophysics; Interface Design and Evaluation; User Experience; Musical Performanc

    Advanced Occupancy Measurement Using Sensor Fusion

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    With roughly about half of the energy used in buildings attributed to Heating, Ventilation, and Air conditioning (HVAC) systems, there is clearly great potential for energy saving through improved building operations. Accurate knowledge of localised and real-time occupancy numbers can have compelling control applications for HVAC systems. However, existing technologies applied for building occupancy measurements are limited, such that a precise and reliable occupant count is difficult to obtain. For example, passive infrared (PIR) sensors commonly used for occupancy sensing in lighting control applications cannot differentiate between occupants grouped together, video sensing is often limited by privacy concerns, atmospheric gas sensors (such as CO2 sensors) may be affected by the presence of electromagnetic (EMI) interference, and may not show clear links between occupancy and sensor values. Past studies have indicated the need for a heterogeneous multi-sensory fusion approach for occupancy detection to address the short-comings of existing occupancy detection systems. The aim of this research is to develop an advanced instrumentation strategy to monitor occupancy levels in non-domestic buildings, whilst facilitating the lowering of energy use and also maintaining an acceptable indoor climate. Accordingly, a novel multi-sensor based approach for occupancy detection in open-plan office spaces is proposed. The approach combined information from various low-cost and non-intrusive indoor environmental sensors, with the aim to merge advantages of various sensors, whilst minimising their weaknesses. The proposed approach offered the potential for explicit information indicating occupancy levels to be captured. The proposed occupancy monitoring strategy has two main components; hardware system implementation and data processing. The hardware system implementation included a custom made sound sensor and refinement of CO2 sensors for EMI mitigation. Two test beds were designed and implemented for supporting the research studies, including proof-of-concept, and experimental studies. Data processing was carried out in several stages with the ultimate goal being to detect occupancy levels. Firstly, interested features were extracted from all sensory data collected, and then a symmetrical uncertainty analysis was applied to determine the predictive strength of individual sensor features. Thirdly, a candidate features subset was determined using a genetic based search. Finally, a back-propagation neural network model was adopted to fuse candidate multi-sensory features for estimation of occupancy levels. Several test cases were implemented to demonstrate and evaluate the effectiveness and feasibility of the proposed occupancy detection approach. Results have shown the potential of the proposed heterogeneous multi-sensor fusion based approach as an advanced strategy for the development of reliable occupancy detection systems in open-plan office buildings, which can be capable of facilitating improved control of building services. In summary, the proposed approach has the potential to: (1) Detect occupancy levels with an accuracy reaching 84.59% during occupied instances (2) capable of maintaining average occupancy detection accuracy of 61.01%, in the event of sensor failure or drop-off (such as CO2 sensors drop-off), (3) capable of utilising just sound and motion sensors for occupancy levels monitoring in a naturally ventilated space, (4) capable of facilitating potential daily energy savings reaching 53%, if implemented for occupancy-driven ventilation control

    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 199

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    This bibliography lists 82 reports, articles, and other documents introduced into the NASA scientific and technical information system in October 1979

    Improvements in optical techniques to investigate the behavior and neuronal network dynamics over long timescales

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    Developments in optical technology have produced an important shift in experimental neuroscience from electrophysiological methods for observation and stimulation to all-optical solutions. One expects this trend to continue as future developments continue to deliver, and improve upon, the original promises of the technology: 1) minimally invasive actuation and recording of neurons, and 2) a drastic increase in targets that can be treated simultaneously. Moreover, as the high costs of the technology are reduced, one may expect its larger-scale adoption in the neuroscience community. In this thesis, I describe the development and implementation of two alloptical solutions for the analysis of behavior, neuronal signaling, and stimulation, which improve on previous state-of-the-art: (1) A minimally-invasive, high signal-to-noise twophoton microscopy setup capable of simultaneous, live-imaging of a large subset of sensory neurons post activation, and (2) a low-cost tracking solution to stimulate and record behavior. I begin this thesis with a review of recent advances in optical neuroscience techniques for the study of neuronal networks with the focus on work done in Caenorhabditis elegans. Then, in chapter 2, I describe my implementation of a two-photon temporal focusing microscopy setup and show significant improvements through the use of a high power/ high pulse repetition rate excitation system, enabling live imaging with high resolution for extended periods of time. I model temperature increase during a physiological imaging scenario for different repetition rates at fixed peak intensities and find range centered around 1 MHz to be optimal. Lastly, I describe the low-cost tracking setup with the ability to stimulate and record behavior over the course of hours. The setup is capable of two-color stimulation of optogenetic proteins over the area of the behavioral arena in combination with volatile chemicals. To showcase the utility of the system, I demonstrate behavioral analysis of integration of contradictory cues. In summary, I present a set of techniques for the interrogation of neural networks from animal behavior to neuronal activity, over timescales of potentially hours and days. These techniques can be used to address a new dimension of scientific questions.Okinawa Institute of Science and Technology Graduate Universit

    \u3cem\u3eGRASP News\u3c/em\u3e, Volume 6, Number 1

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    A report of the General Robotics and Active Sensory Perception (GRASP) Laboratory, edited by Gregory Long and Alok Gupta
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