185 research outputs found

    CO3 for ultra-fast and accurate interactive segmentation

    Full text link

    Fine Art Pattern Extraction and Recognition

    Get PDF
    This is a reprint of articles from the Special Issue published online in the open access journal Journal of Imaging (ISSN 2313-433X) (available at: https://www.mdpi.com/journal/jimaging/special issues/faper2020)

    New advances in vehicular technology and automotive engineering

    Get PDF
    An automobile was seen as a simple accessory of luxury in the early years of the past century. Therefore, it was an expensive asset which none of the common citizen could afford. It was necessary to pass a long period and waiting for Henry Ford to establish the first plants with the series fabrication. This new industrial paradigm makes easy to the common American to acquire an automobile, either for running away or for working purposes. Since that date, the automotive research grown exponentially to the levels observed in the actuality. Now, the automobiles are indispensable goods; saying with other words, the automobile is a first necessity article in a wide number of aspects of living: for workers to allow them to move from their homes into their workplaces, for transportation of students, for allowing the domestic women in their home tasks, for ambulances to carry people with decease to the hospitals, for transportation of materials, and so on, the list don’t ends. The new goal pursued by the automotive industry is to provide electric vehicles at low cost and with high reliability. This commitment is justified by the oil’s peak extraction on 50s of this century and also by the necessity to reduce the emissions of CO2 to the atmosphere, as well as to reduce the needs of this even more valuable natural resource. In order to achieve this task and to improve the regular cars based on oil, the automotive industry is even more concerned on doing applied research on technology and on fundamental research of new materials. The most important idea to retain from the previous introduction is to clarify the minds of the potential readers for the direct and indirect penetration of the vehicles and the vehicular industry in the today’s life. In this sequence of ideas, this book tries not only to fill a gap by presenting fresh subjects related to the vehicular technology and to the automotive engineering but to provide guidelines for future research. This book account with valuable contributions from worldwide experts of automotive’s field. The amount and type of contributions were judiciously selected to cover a broad range of research. The reader can found the most recent and cutting-edge sources of information divided in four major groups: electronics (power, communications, optics, batteries, alternators and sensors), mechanics (suspension control, torque converters, deformation analysis, structural monitoring), materials (nanotechnology, nanocomposites, lubrificants, biodegradable, composites, structural monitoring) and manufacturing (supply chains). We are sure that you will enjoy this book and will profit with the technical and scientific contents. To finish, we are thankful to all of those who contributed to this book and who made it possible.info:eu-repo/semantics/publishedVersio

    tracker independent drift detection and correction using segmented objects and features

    Get PDF
    Object tracking has been an active research topic in the field of video processing. However, automated object tracking, under uncontrolled environments, is still difficult to achieve and encounters various challenges that cause the tracker to drift away from the target object. %Object tracking methods with fixed models, that are predefined prior to the tracking task, normally fail because of the inevitable appearance changes that can be either object or environment-related. To effectively handle object or environment tracking challenges, recent powerful tracking approaches are learning-based, meaning they learn object appearance changes while tracking online. The output of such trackers is, however, limited to a bounding box representation, the center of which is considered as the estimated object location. Such bounding box may not provide accurate foreground/background discrimination and may not handle highly non-rigid objects. Moreover, the bounding box may not surround the object completely, or it may not be centered around it, which affects the accuracy of the overall tracking process. Our main objective in this work is to reduce drifts of state-of-the-art tracking algorithms (trackers) using object segmentation so to produce more accurate bounding box. To enhance the quality of state-of-the-art trackers, this work investigates two main venues: first tracker-independent drift detection and correction using object features and second, selection of best performing parameters of Graph Cut object segmentation and of support vector machines using artificial immune system. In addition, this work proposes a framework for the evaluation and ranking of different trackers using easily interpretable performance measures, in a way to account for the presence of outliers. For tracker-independent drift detection, we use saliency features or objectness using saliency, the ratio of the salient region corresponding to the target object with respect to the estimated bounding box is used to indicate the occurrence of tracking drift with no prior information about the target model. With objectness measures, we use both relative area and score of the detected candidate boxes according to the objectness measure to indicate the occurrenece of the tracking drift. For drift correction, we investigate the application of object segmentation on the estimated bounding box to re-locate it around the target object. Due to its ability to lead to a global near optimal solution, we use the Graph Cut object segmentation method. We modify the Graph Cut model to incorporate an automatic seed selection module based on interest points, in addition to a template mask, to automatically initialize the segmentation across frames. However, the integration of segmentation in the tracking loop has its computational burden. In addition, the segmentation quality might be affected by tracking challenges, such as motion blur and occlusion. Accordingly, object segmentation is applied only when a drift is detected. Simulation results show that the proposed approach improves the tracking quality of five recent trackers. Researchers often use long and tedious trial and error approaches for determining the best performing parameter configuration of a video-processing algorithm, particularly with the diverse nature of video sequences. However, such configuration does not guarantee the best performance. A little research attention has been given to study the algorithm's sensitivity to its parameters. Artificial immune system is an emergent biologically motivated computing paradigm that has the ability to reach optimal or near-optimal solutions through mutation and cloning. This work proposes the use of artificial immune system for the selection of best performing parameters of two video processing algorithms: support vector machines for object tracking and Graph Cut based object segmentation. An increasing number of trackers are being developed and when introducing a new tracker, it is important to facilitate its evaluation and ranking in relation to others, using easy to interpret performance measures. Recent studies have shown that some measures are correlated and cannot reflect the different aspects of tracking performance when used individually. In addition, they do not incorporate robust statistics to account for the presence of outliers that might lead to insignificant results. This work proposes a framework for effective scoring and ranking of different trackers by using less correlated quality metrics, coupled with a robust estimator against dispersion. In addition, a unified performance index is proposed to facilitate the evaluation process

    Méthodes multi-organes rapides avec a priori de forme pour la localisation et la segmentation en imagerie médicale 3D

    Get PDF
    With the ubiquity of imaging in medical applications (diagnostic, treatment follow-up, surgery planning. . . ), image processing algorithms have become of primary importance. Algorithms help clinicians extract critical information more quickly and more reliably from increasingly large and complex acquisitions. In this context, anatomy localization and segmentation is a crucial component in modern clinical workflows. Due to particularly high requirements in terms of robustness, accuracy and speed, designing such tools remains a challengingtask.In this work, we propose a complete pipeline for the segmentation of multiple organs in medical images. The method is generic, it can be applied to varying numbers of organs, on different imaging modalities. Our approach consists of three components: (i) an automatic localization algorithm, (ii) an automatic segmentation algorithm, (iii) a framework for interactive corrections. We present these components as a coherent processing chain, although each block could easily be used independently of the others. To fulfill clinical requirements, we focus on robust and efficient solutions. Our anatomy localization method is based on a cascade of Random Regression Forests (Cuingnet et al., 2012). One key originality of our work is the use of shape priors for each organ (thanks to probabilistic atlases). Combined with the evaluation of the trained regression forests, they result in shape-consistent confidence maps for each organ instead of simple bounding boxes. Our segmentation method extends the implicit template deformation framework of Mory et al. (2012) to multiple organs. The proposed formulation builds on the versatility of the original approach and introduces new non-overlapping constraintsand contrast-invariant forces. This makes our approach a fully automatic, robust and efficient method for the coherent segmentation of multiple structures. In the case of imperfect segmentation results, it is crucial to enable clinicians to correct them easily. We show that our automatic segmentation framework can be extended with simple user-driven constraints to allow for intuitive interactive corrections. We believe that this final component is key towards the applicability of our pipeline in actual clinical routine.Each of our algorithmic components has been evaluated on large clinical databases. We illustrate their use on CT, MRI and US data and present a user study gathering the feedback of medical imaging experts. The results demonstrate the interest in our method and its potential for clinical use.Avec l’utilisation de plus en plus répandue de l’imagerie dans la pratique médicale (diagnostic, suivi, planification d’intervention, etc.), le développement d’algorithmes d’analyse d’images est devenu primordial. Ces algorithmes permettent aux cliniciens d’analyser et d’interpréter plus facilement et plus rapidement des données de plus en plus complexes. Dans ce contexte, la localisation et la segmentation de structures anatomiques sont devenues des composants critiques dans les processus cliniques modernes. La conception de tels outils pour répondre aux exigences de robustesse, précision et rapidité demeure cependant un réel défi technique.Ce travail propose une méthode complète pour la segmentation de plusieurs organes dans des images médicales. Cette méthode, générique et pouvant être appliquée à un nombre varié de structures et dans différentes modalités d’imagerie, est constituée de trois composants : (i) un algorithme de localisation automatique, (ii) un algorithme de segmentation, (iii) un outil de correction interactive. Ces différentes parties peuvent s’enchaîner aisément pour former un outil complet et cohérent, mais peuvent aussi bien être utilisées indépendemment. L’accent a été mis sur des méthodes robustes et efficaces afin de répondre aux exigences cliniques. Notre méthode de localisation s’appuie sur une cascade de régression par forêts aléatoires (Cuingnet et al., 2012). Elle introduit l’utilisation d’informations a priori de forme, spécifiques à chaque organe (grâce à des atlas probabilistes) pour des résultats plus cohérents avec la réalité anatomique. Notre méthode de segmentation étend la méthode de segmentation par modèle implicite (Mory et al., 2012) à plusieurs modèles. La formulation proposée permet d’obtenir des déformations cohérentes, notamment en introduisant des contraintes de non recouvrement entre les modèles déformés. En s’appuyant sur des forces images polyvalentes, l’approche proposée se montre robuste et performante pour la segmentation de multiples structures. Toute méthode automatique n’est cependant jamais parfaite. Afin que le clinicien garde la main sur le résultat final, nous proposons d’enrichir la formulation précédente avec des contraintes fournies par l’utilisateur. Une optimisation localisée permet d’obtenir un outil facile à utiliser et au comportement intuitif. Ce dernier composant est crucial pour que notre outil soit réellement utilisable en pratique. Chacun de ces trois composants a été évalué sur plusieurs grandes bases de données cliniques (en tomodensitométrie, imagerie par résonance magnétique et ultrasons). Une étude avec des utilisateurs nous a aussi permis de recueillir des retours positifs de plusieurs experts en imagerie médicale. Les différents résultats présentés dans ce manuscrit montrent l’intérêt de notre méthode et son potentiel pour une utilisation clinique

    FY10 Engineering Innovations, Research and Technology Report

    Full text link

    Department of Radiology-Annual Report-July 1, 1997 to June 30, 1998

    Get PDF
    Department of Radiology Annual Executive Summary Report, July 1, 1997 to June 30, 1998. Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States. 103 pages

    Development of an autonomous water sampler

    No full text
    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Advanced characterisation techniques for battery safety assessment

    Get PDF
    The need to shift to cleaner energy sources is imperative. Battery technology is considered a highly promising technology to successfully bring about this shift. It has already been implemented in numerous ways and features in our day-to-day lives; from mobile phones to homes. Recently, concerns regarding their safety have increased and as a result, governments have boosted research efforts in this area, with the added urge to work collectively with industry partners and regulatory bodies. These cells are prone to undergo catastrophic failures as a result of a series of exothermic reactions (thermal runaway) that can be triggered by several methods. Many research efforts have been made to understand this phenomenon from various perspectives: material selection, mechanical design, mitigation or preventative measures. This thesis shows how we can begin to comprehend this complexity and apply it to advancing existing battery safety assessment techniques. Through thermal analyses and multi-scale X-ray CT imaging, the correlations between heat generation and battery architecture are addressed. In this work, for the first time, differential scanning calorimetry was used to measure heat signals from full cells, high aspect ratio battery samples were imaged and a custom-built calorimeter chamber was developed to provide operando images and heat measurements of cells undergoing thermal failure. The results obtained from the methodologies and techniques established in this work have advanced our understanding of how various battery material morphologies and architectures behave under certain stresses. In turn, these findings can aid not only in the development and manufacture of safer lithium-ion batteries but also in the standardisation of testing standards, and improvement of failure mitigation strategies
    • …
    corecore