100 research outputs found

    People tracking and re-identification by face recognition for RGB-D camera networks

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    This paper describes a face recognition-based people tracking and re-identification system for RGB-D camera networks. The system tracks people and learns their faces online to keep track of their identities even if they move out from the camera's field of view once. For robust people re-identification, the system exploits the combination of a deep neural network- based face representation and a Bayesian inference-based face classification method. The system also provides a predefined people identification capability: it associates the online learned faces with predefined people face images and names to know the people's whereabouts, thus, allowing a rich human-system interaction. Through experiments, we validate the re-identification and the predefined people identification capabilities of the system and show an example of the integration of the system with a mobile robot. The overall system is built as a Robot Operating System (ROS) module. As a result, it simplifies the integration with the many existing robotic systems and algorithms which use such middleware. The code of this work has been released as open-source in order to provide a baseline for the future publications in this field

    A portable three-dimensional LIDAR-based system for long-term and wide-area people behavior measurement:

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    It is important to measure and analyze people behavior to design systems which interact with people. This article describes a portable people behavior measurement system using a three-dimensional LIDAR. In this system, an observer carries the system equipped with a three-dimensional Light Detection and Ranging (LIDAR) and follows persons to be measured while keeping them in the sensor view. The system estimates the sensor pose in a three-dimensional environmental map and tracks the target persons. It enables long-term and wide-area people behavior measurements which are hard for existing people tracking systems. As a field test, we recorded the behavior of professional caregivers attending elderly persons with dementia in a hospital. The preliminary analysis of the behavior reveals how the caregivers decide the attending position while checking the surrounding people and environment. Based on the analysis result, empirical rules to design the behavior of attendant robots are proposed

    Exact Point Cloud Downsampling for Fast and Accurate Global Trajectory Optimization

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    This paper presents a point cloud downsampling algorithm for fast and accurate trajectory optimization based on global registration error minimization. The proposed algorithm selects a weighted subset of residuals of the input point cloud such that the subset yields exactly the same quadratic point cloud registration error function as that of the original point cloud at the evaluation point. This method accurately approximates the original registration error function with only a small subset of input points (29 residuals at a minimum). Experimental results using the KITTI dataset demonstrate that the proposed algorithm significantly reduces processing time (by 87\%) and memory consumption (by 99\%) for global registration error minimization while retaining accuracy.Comment: IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS2023

    Single-Shot Global Localization via Graph-Theoretic Correspondence Matching

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    This paper describes a method of global localization based on graph-theoretic association of instances between a query and the prior map. The proposed framework employs correspondence matching based on the maximum clique problem (MCP). The framework is potentially applicable to other map and/or query modalities thanks to the graph-based abstraction of the problem, while many of existing global localization methods rely on a query and the dataset in the same modality. We implement it with a semantically labeled 3D point cloud map, and a semantic segmentation image as a query. Leveraging the graph-theoretic framework, the proposed method realizes global localization exploiting only the map and the query. The method shows promising results on multiple large-scale simulated maps of urban scenes

    Thoracic endovascular aneurysm repair in Japan: Experience with fenestrated stent grafts in the treatment of distal arch aneurysms

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    ObjectivesIn the West, stent grafts for endovascular repair of thoracic aortic aneurysms have been commercially available for several years, whereas in Japan, a manufactured stent graft was not approved for this application until March 2008. Nevertheless, endovascular thoracic intervention began to be performed in Japan in the early 1990s, with homemade devices used in most cases. Many researchers have continued to develop homemade devices. We have participated in joint design and assessment efforts with a stent graft manufacturer, focusing primarily on fenestrated stent grafts used in repairs at the distal arch, a site especially prone to aneurysm.MethodsFrom 1995 to February 2008, we performed about 1100 endovascular procedures to treat thoracic aortic aneurysms and 682 cases were performed at Tokyo Medical University. In 435 out of 682 the aneurysm was located in the area from the distal arch to the proximal descending aorta. Fenestrated stent grafts were inserted in 288 cases. Computed tomography scans were performed at 3, 6, and 12 months postoperatively and annually thereafter.ResultsThe initial success rate in the entire series was 95.2%. Complications included 26 cerebral infarctions (3.8%), six of which (0.9%) resulted in serious paralysis and changes in consciousness. Among patients who received fenestrated stent grafts, paraplegia occurred in 2.6%, aortic injury in 1.2%, and iliofemoral artery injury in 6.0%. No complications resulted from occlusion of aortic arch branches. At ≥2 years after intervention, aneurysm diameter was reduced in 62% of patients, 33% had no change, and 5% had a diameter enlargement. The stent graft complication rate during follow-up was 8.4%, the device fracture rate was 1.4%, and the device migration rate was 7%. The 5-year survival rate was 62.4%, with follow-up in 96.8% of the patients.ConclusionEndovascular repair has promising results in the descending thoracic aortic region, although some stent grafts and their delivery systems can still be improved. Additional commercial developments and available stent grafts designed for use in the distal arch are urgently needed

    Legionella pneumophila infection induces programmed cell death, caspase activation, and release of high-mobility group box 1 protein in A549 alveolar epithelial cells: inhibition by methyl prednisolone

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    <p>Abstract</p> <p>Background</p> <p><it>Legionella pneumophila </it>pneumonia often exacerbates acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Apoptosis of alveolar epithelial cells is considered to play an important role in the pathogenesis of ALI and ARDS. In this study, we investigated the precise mechanism by which A549 alveolar epithelial cells induced by <it>L. pneumophila </it>undergo apoptosis. We also studied the effect of methyl prednisolone on apoptosis in these cells.</p> <p>Methods</p> <p>Nuclear deoxyribonucleic acid (DNA) fragmentation and caspase activation in <it>L. pneumophila</it>-infected A549 alveolar epithelial cells were assessed using the terminal deoxyribonucleotidyl transferase-mediated triphosphate (dUTP)-biotin nick end labeling method (TUNEL method) and colorimetric caspase activity assays. The virulent <it>L. pneumophila </it>strain AA100jm and the avirulent <it>dotO </it>mutant were used and compared in this study. In addition, we investigated whether methyl prednisolone has any influence on nuclear DNA fragmentation and caspase activation in A549 alveolar epithelial cells infected with <it>L. pneumophila</it>.</p> <p>Results</p> <p>The virulent strain of <it>L. pneumophila </it>grew within A549 alveolar epithelial cells and induced subsequent cell death in a dose-dependent manner. The avirulent strain <it>dotO </it>mutant showed no such effect. The virulent strains of <it>L. pneumophila </it>induced DNA fragmentation (shown by TUNEL staining) and activation of caspases 3, 8, 9, and 1 in A549 cells, while the avirulent strain did not. High-mobility group box 1 (HMGB1) protein was released from A549 cells infected with virulent <it>Legionella</it>. Methyl prednisolone (53.4 μM) did not influence the intracellular growth of <it>L. pneumophila </it>within alveolar epithelial cells, but affected DNA fragmentation and caspase activation of infected A549 cells.</p> <p>Conclusion</p> <p>Infection of A549 alveolar epithelial cells with <it>L. pneumophila </it>caused programmed cell death, activation of various caspases, and release of HMGB1. The dot/icm system, a major virulence factor of <it>L. pneumophila</it>, is involved in the effects we measured in alveolar epithelial cells. Methyl prednisolone may modulate the interaction of <it>Legionella </it>and these cells.</p

    Status and promise of particle interferometry in heavy-ion collisions

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    After five years of running at RHIC, and on the eve of the LHC heavy-ion program, we highlight the status of femtoscopic measurements. We emphasize the role interferometry plays in addressing fundamental questions about the state of matter created in such collisions, and present an enumerated list of measurements, analyses and calculations that are needed to advance the field in the coming years
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