93 research outputs found

    Application of data fusion techniques and technologies for wearable health monitoring

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    Technological advances in sensors and communications have enabled discrete integration into everyday objects, both in the home and about the person. Information gathered by monitoring physiological, behavioural, and social aspects of our lives, can be used to achieve a positive impact on quality of life, health, and well-being. Wearable sensors are at the cusp of becoming truly pervasive, and could be woven into the clothes and accessories that we wear such that they become ubiquitous and transparent. To interpret the complex multidimensional information provided by these sensors, data fusion techniques are employed to provide a meaningful representation of the sensor outputs. This paper is intended to provide a short overview of data fusion techniques and algorithms that can be used to interpret wearable sensor data in the context of health monitoring applications. The application of these techniques are then described in the context of healthcare including activity and ambulatory monitoring, gait analysis, fall detection, and biometric monitoring. A snap-shot of current commercially available sensors is also provided, focusing on their sensing capability, and a commentary on the gaps that need to be bridged to bring research to market

    Steering control for haptic feedback and active safety functions

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    Steering feedback is an important element that defines driver–vehicle interaction. It strongly affects driving performance and is primarily dependent on the steering actuator\u27s control strategy. Typically, the control method is open loop, that is without any reference tracking; and its drawbacks are hardware dependent steering feedback response and attenuated driver–environment transparency. This thesis investigates a closed-loop control method for electric power assisted steering and steer-by-wire systems. The advantages of this method, compared to open loop, are better hardware impedance compensation, system independent response, explicit transparency control and direct interface to active safety functions.The closed-loop architecture, outlined in this thesis, includes a reference model, a feedback controller and a disturbance observer. The feedback controller forms the inner loop and it ensures: reference tracking, hardware impedance compensation and robustness against the coupling uncertainties. Two different causalities are studied: torque and position control. The two are objectively compared from the perspective of (uncoupled and coupled) stability, tracking performance, robustness, and transparency.The reference model forms the outer loop and defines a torque or position reference variable, depending on the causality. Different haptic feedback functions are implemented to control the following parameters: inertia, damping, Coulomb friction and transparency. Transparency control in this application is particularly novel, which is sequentially achieved. For non-transparent steering feedback, an environment model is developed such that the reference variable is a function of virtual dynamics. Consequently, the driver–steering interaction is independent from the actual environment. Whereas, for the driver–environment transparency, the environment interaction is estimated using an observer; and then the estimated signal is fed back to the reference model. Furthermore, an optimization-based transparency algorithm is proposed. This renders the closed-loop system transparent in case of environmental uncertainty, even if the initial condition is non-transparent.The steering related active safety functions can be directly realized using the closed-loop steering feedback controller. This implies, but is not limited to, an angle overlay from the vehicle motion control functions and a torque overlay from the haptic support functions.Throughout the thesis, both experimental and the theoretical findings are corroborated. This includes a real-time implementation of the torque and position control strategies. In general, it can be concluded that position control lacks performance and robustness due to high and/or varying system inertia. Though the problem is somewhat mitigated by a robust H-infinity controller, the high frequency haptic performance remains compromised. Whereas, the required objectives are simultaneously achieved using a torque controller

    Trophic classification of selected Colorado lakes

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    Multispectral scanner data, acquired over several Colorado lakes using LANDSAT-1 and aircraft, were used in conjunction with contact-sensed water quality data to determine the feasibility of assessing lacustrine trophic levels. A trophic state index was developed using contact-sensed data for several trophic indicators. Relationships between the digitally processed multispectral scanner data, several trophic indicators, and the trophic index were examined using a supervised multispectral classification technique and regression techniques. Statistically significant correlations exist between spectral bands, several of the trophic indicators and the trophic state index. Color-coded photomaps were generated which depict the spectral aspects of trophic state

    Court-System Transparency

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    This article applies systems analysis to two ends. First, it identifies simple changes that would make the court system transparent. Second, it projects transparency\u27s consequences. Transparency means that both the patterns across, and details of, case files are revealed to policymakers, litigants, and the public in easily understood forms. Government must make two changes to achieve court system transparency. The first is to remove the existing restrictions on the electronic release of court documents, including the requirements for registration, separate requests for each document, and monetary payment. The second - already being implemented in the federal courts - is to require the use of data-enabled forms. Once these changes are in place, institutions and private parties will process the available data at the parties\u27 own expense. That processing will generate millions of real-time views of court system operation using automatically-updated regression analyses and both textual and graphical data displays. The effect would be a renaissance. Corruption, incompetence, inefficiency, prejudice and favoritism would be exposed and wither. Litigation would be cheap and easy because parties could see all court files in the system and copy the work of others. Policy makers could see the human consequences of the laws they enact and adjust accordingly. Lawyers could predict the outcomes of their cases, making litigation less necessary. Citizens would for the first time be able to derive and see the real rules by which they are governed. Transparency would have a minimal effect on privacy. The data processed are already public record and adequate privacy protections are already provided through sealing orders and redaction requirements. Transparency would generate pressures on judges and court administrators, but the effects of those pressures would be generally positive. Limitations on the public enforcement of private arbitration awards might be necessary to prevent parties from opting out of the transparent system

    Lightness, Brightness, and Transparency in Optical See-Through Augmented Reality

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    Augmented reality (AR), as a key component of the future metaverse, has leaped from the research labs to the consumer and enterprise markets. AR optical see-through (OST) devices utilize transparent optical combiners to provide visibility of the real environment as well as superimpose virtual content on top of it. OST displays distinct from existing media because of their optical additivity, meaning the light reaching the eyes is composed of both virtual content and real background. The composition results in the intended virtual colors being distorted and perceived transparent. When the luminance of the virtual content decreases, the perceived lightness and brightness decrease, and the perceived transparency increases. Lightness, brightness, and transparency are modulated by one physical dimension (luminance), and all interact with the background and each other. In this research, we aim to identify and quantify the three perceptual dimensions, as well as build mathematical models to predict them. In the first part of the study, we focused on the perceived brightness and lightness with two experiments: a brightness partition scaling experiment to build brightness scales, and a diffuse white adjustment experiment to determine the absolute luminance level required for diffuse white appearances on 2D and 3D AR stimuli. The second part of the research targeted at the perceived transparency in the AR environment with three experiments. The transparency was modulated by the background Michelson contrast reduction in either average luminance or peak-to-peak luminance difference to investigate, and later illustrated, the fundamental mechanism evoking transparency perception. The first experiment measured the transparency detection thresholds and confirmed that contrast sensitivity functions with contrast adaptation could model the thresholds. Subsequently, the transparency perception was investigated through direct anchored scaling experiment by building perceived transparency scales from the virtual content contrast ratio to the background. A contrast-ratio-based model was proposed predicting the perceived transparency scales. Finally, the transparency equivalency experiment between the two types of contrast modulation confirmed the mechanism difference and validated the proposed model

    The Role of the Lateral Geniculate Nucleus in Developmental Dyslexia: Evidence From Multi-Modal Magnetic Resonance Imaging

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    The ability to read proficiently is key to social participation and an important premise for individual well-being and vocational success. Individuals with developmental dyslexia, a highly prevalent neurodevelopmental disorder affecting hundreds of millions of children and adults worldwide, face severe and persistent difficulties in attaining adequate reading levels. Despite years of extensive research efforts to elucidate the neurobiological origin of this disorder, its exact etiology remains unclear to date. In this context, most neuroimaging research on dyslexia in humans has focused on the cerebral cortex and has identified alterations in a distributed left-lateralized cortical language network. However, pioneering post-mortem human studies and animal models suggest that dyslexia might also be associated with alterations in subcortical sensory thalami and early sensory pathways. The largely cortico-centric view of dyslexia is due in part to considerable technical challenges in assessing the human sensory thalami non-invasively using conventional magnetic resonance imaging (MRI). As a result, the role that sensory thalami may play in dyslexia has been largely unaddressed. In this dissertation, I leveraged recent advances in high-field MRI to investigate the role of the human lateral geniculate nucleus (LGN) of the visual thalamus in adults with dyslexia in-vivo. In three multi-modal high-field MRI studies, I show that (i) dyslexia is associated with structural alterations in the direct V1-bypassing white matter pathway connecting the LGN with cortical motion-sensitive area V5/MT in the left hemisphere; (ii) the connectivity strength of which predicts a core symptom of the disorder, i.e., rapid naming ability. I further demonstrate that (iii) the two major functional subdivisions of the LGN can be distinguished non-invasively based on differences in tissue microstructure; and that (iv) adults with dyslexia show functional response alterations specifically in the magnocellular subdivision of the LGN. I also demonstrate that this subdivision deficit (v) is more pronounced in male than female dyslexics; and (vi) predicts rapid naming ability in male dyslexics only. The results of this doctoral thesis are the first to confirm previous post-mortem evidence of LGN alterations in dyslexia in-vivo and point to their relevance to key symptoms of the disorder. In synergy, our research findings offer new perspectives on explanatory models of dyslexia and bear potential implications also for prospective treatment strategies.:Contribution Statement i Acknowledgments iii Abstract v Table of Contents vii 1 General Introduction 1 1.1 Developmental Dyslexia 1 1.1.1 Diagnostic Criteria 1 1.1.2 Prevalence and Etiology 2 1.1.3 Cognitive and Behavioral Symptoms 3 1.1.4 Explanatory Models in Cognitive Neuroscience 4 1.2 Lateral Geniculate Nucleus 7 1.2.1 Anatomy and Function 7 1.2.2 Technical Challenges in Conventional MRI 8 1.2.3 High-Field MRI 9 1.3 Research Aim and Chapter Outline 10 2 Altered Structural Connectivity of the Left Visual Thalamus in Developmental Dyslexia 13 2.1 Summary 14 2.2 Results and Discussion 15 2.3 Conclusions 22 2.4 Materials and Methods 23 2.4.1 Subject Details 23 2.4.2 High-Resolution MRI Acquisition and Preprocessing 23 2.4.3 Lateral Geniculate Nucleus Definition 24 2.4.4 Cortical Region of Interest Definition 26 2.4.5 Probabilistic Tractography 27 2.4.6 Quantification and Statistical Analysis 29 2.5 Supplementary Information 30 3 Mapping the Human Lateral Geniculate Nucleus and its Cytoarchitectonic Subdivisions Using Quantitative MRI 33 3.1 Abstract 34 3.2 Introduction 35 3.3 Materials and Methods 37 3.3.1 In-Vivo MRI 37 3.3.2 Post-Mortem MRI and Histology 41 3.4 Results 44 3.4.1 Lateral Geniculate Nucleus Subdivisions in In-Vivo MRI 44 3.4.2 Lateral Geniculate Nucleus Subdivisions in Post-Mortem MRI 46 3.5 Discussion 50 3.6 Supplementary Information 54 3.6.1 In-Vivo MRI 54 3.6.2 Post-Mortem MRI and Histology 58 3.6.3 Data and Code Availability 60 4 Dysfunction of the Visual Sensory Thalamus in Developmental Dyslexia 61 4.1 Abstract 62 4.2 Introduction 63 4.3 Materials and Methods 66 4.3.1 Subject Details 66 4.3.2 High-Resolution MRI Experiments 66 4.3.3 High-Resolution MRI Acquisition and Preprocessing 67 4.3.4 Lateral Geniculate Nucleus Definition 68 4.3.5 Quantification and Statistical Analysis 69 4.4 Results 70 4.5 Discussion 75 4.6 Supplementary Information 77 4.6.1 Supporting Methods 77 4.6.2 Supporting Results 81 4.6.3 Data and Code Availability 82 5 General Conclusion 83 5.1 Summary of Research Findings 83 5.2 Implications for Dyslexia Models 84 5.2.1 Phonological Deficit Hypothesis 84 5.2.2 Magnocellular Theory 84 5.2.3 Model According to Ramus 85 5.2.4 Need for Revised Model 86 5.3 Implications for Remediation 87 5.4 Research Prospects 88 5.5 Brief Concluding Remarks 90 6 Bibliography 91 7 List of Tables 113 8 List of Figures 115 9 Selbstständigkeitserklärung 11

    Object localisation, dimensions estimation and tracking.

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    PhD Theses.Localising, estimating the physical properties of, and tracking objects from audio and video signals are the base for a large variety of applications such as surveillance, search and rescue, extraction of objects’ patterns and robotic applications. These tasks are challenging due to low signal-to-noise ratio, multiple moving objects, occlusions and changes in objects’ appearance. Moreover, these tasks become more challenging when real-time performance is required and when the sensor is mounted in a moving platform such as a robot, which introduces further problems due to potentially quick sensor motions and noisy observations. In this thesis, we consider algorithms for single and multiple object tracking from static microphones and cameras, and moving cameras without relying on additional sensors or making strong assumptions about the objects or the scene; and localisation and estimation of the 3D physical properties of unseen objects. We propose an online multi-object tracker that addresses noisy observations by exploiting the confidence on object observations and also addresses the challenges of object and camera motion by introducing a real-time object motion predictor that forecasts the future location of objects with uncalibrated cameras. The proposed method enables real-time tracking by avoiding computationally expensive labelling procedures such as clustering for data association. Moreover, we propose a novel multi-view algorithm for jointly localising and estimating the 3D physical properties of objects via semantic segmentation and projective geometry without the need to use additional sensors or markers. We validate the proposed methods in three standard benchmarks, two self-collected datasets, and two real robotic applications that involve an unmanned aerial vehicle and a robotic arm. Experimental results show that the proposed methods improve existing alternatives in terms of accuracy and speed

    Robotics, AI, and Humanity

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    This open access book examines recent advances in how artificial intelligence (AI) and robotics have elicited widespread debate over their benefits and drawbacks for humanity. The emergent technologies have for instance implications within medicine and health care, employment, transport, manufacturing, agriculture, and armed conflict. While there has been considerable attention devoted to robotics/AI applications in each of these domains, a fuller picture of their connections and the possible consequences for our shared humanity seems needed. This volume covers multidisciplinary research, examines current research frontiers in AI/robotics and likely impacts on societal well-being, human – robot relationships, as well as the opportunities and risks for sustainable development and peace. The attendant ethical and religious dimensions of these technologies are addressed and implications for regulatory policies on the use and future development of AI/robotics technologies are elaborated

    Flexible and Stretchable Electronics

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    Flexible and stretchable electronics are receiving tremendous attention as future electronics due to their flexibility and light weight, especially as applications in wearable electronics. Flexible electronics are usually fabricated on heat sensitive flexible substrates such as plastic, fabric or even paper, while stretchable electronics are usually fabricated from an elastomeric substrate to survive large deformation in their practical application. Therefore, successful fabrication of flexible electronics needs low temperature processable novel materials and a particular processing development because traditional materials and processes are not compatible with flexible/stretchable electronics. Huge technical challenges and opportunities surround these dramatic changes from the perspective of new material design and processing, new fabrication techniques, large deformation mechanics, new application development and so on. Here, we invited talented researchers to join us in this new vital field that holds the potential to reshape our future life, by contributing their words of wisdom from their particular perspective
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