30 research outputs found

    Raster Time Series: Learning and Processing

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    As the amount of remote sensing data is increasing at a high rate, due to great improvements in sensor technology, efficient processing capabilities are of utmost importance. Remote sensing data from satellites is crucial in many scientific domains, like biodiversity and climate research. Because weather and climate are of particular interest for almost all living organisms on earth, the efficient classification of clouds is one of the most important problems. Geostationary satellites such as Meteosat Second Generation (MSG) offer the only possibility to generate long-term cloud data sets with high spatial and temporal resolution. This work, therefore, addresses research problems on efficient and parallel processing of MSG data to enable new applications and insights. First, we address the lack of a suitable processing chain to generate a long-term Fog and Low Stratus (FLS) time series. We present an efficient MSG data processing chain that processes multiple tasks simultaneously, and raster data in parallel using the Open Computing Language (OpenCL). The processing chain delivers a uniform FLS classification that combines day and night approaches in a single method. As a result, it is possible to calculate a year of FLS rasters quite easy. The second topic presents the application of Convolutional Neural Networks (CNN) for cloud classification. Conventional approaches to cloud detection often only classify single pixels and ignore the fact that clouds are highly dynamic and spatially continuous entities. Therefore, we propose a new method based on deep learning. Using a CNN image segmentation architecture, the presented Cloud Segmentation CNN (CS-CNN) classifies all pixels of a scene simultaneously. We show that CS-CNN is capable of processing multispectral satellite data to identify continuous phenomena such as highly dynamic clouds. The proposed approach provides excellent results on MSG satellite data in terms of quality, robustness, and runtime, in comparison to Random Forest (RF), another widely used machine learning method. Finally, we present the processing of raster time series with a system for Visualization, Transformation, and Analysis (VAT) of spatio-temporal data. It enables data-driven research with explorative workflows and uses time as an integral dimension. The combination of various raster and vector data time series enables new applications and insights. We present an application that combines weather information and aircraft trajectories to identify patterns in bad weather situations

    Knowledge Augmented Machine Learning with Applications in Autonomous Driving: A Survey

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    The existence of representative datasets is a prerequisite of many successful artificial intelligence and machine learning models. However, the subsequent application of these models often involves scenarios that are inadequately represented in the data used for training. The reasons for this are manifold and range from time and cost constraints to ethical considerations. As a consequence, the reliable use of these models, especially in safety-critical applications, is a huge challenge. Leveraging additional, already existing sources of knowledge is key to overcome the limitations of purely data-driven approaches, and eventually to increase the generalization capability of these models. Furthermore, predictions that conform with knowledge are crucial for making trustworthy and safe decisions even in underrepresented scenarios. This work provides an overview of existing techniques and methods in the literature that combine data-based models with existing knowledge. The identified approaches are structured according to the categories integration, extraction and conformity. Special attention is given to applications in the field of autonomous driving

    OPTIMIZATION ALGORITHMS USING PRIORS IN COMPUTER VISION

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    Over the years, many computer vision models, some inspired by human behavior, have been developed for various applications. However, only handful of them are popular and widely used. Why? There are two major factors: 1) most of these models do not have any efficient numerical algorithm and hence they are computationally very expensive; 2) many models, being too generic, cannot capitalize on problem specific prior information and thus demand rigorous hyper-parameter tuning. In this dissertation, we design fast and efficient algorithms to leverage application specific priors to solve unsupervised and weakly-supervised problems. Specifically, we focus on developing algorithms to impose structured priors, model priors and label priors during the inference and/or learning of vision models. In many application, it is known a priori that a signal is smooth and continuous in space. The first part of this work is focussed on improving unsupervised learning mechanisms by explicitly imposing these structured priors in an optimization framework using different regularization schemes. This led to the development of fast algorithms for robust recovery of signals from compressed measurements, image denoising and data clustering. Moreover, by employing re-descending robust penalty on the structured regularization terms and applying duality, we reduce our clustering formulation to an optimization of a single continuous objective. This enabled integration of clustering processes in an end-to-end feature learning pipeline. In the second part of our work, we exploit inherent properties of established models to develop efficient solvers for SDP, GAN, and semantic segmentation. We consider models for several different problem classes. a) Certain non-convex models in computer vision (e.g., BQP) are popularly solved using convex SDPs after lifting to a high-dimensional space. However, this computationally expensive approach limits these methods to small matrices. A fast and approximate algorithm is developed that directly solves the original non-convex formulation using biconvex relaxations and known rank information. b) Widely popular adversarial networks are difficult to train as they suffer from instability issues. This is because optimizing adversarial networks corresponds to finding a saddle-point of a loss function. We propose a simple prediction method that enables faster training of various adversarial networks using larger learning rates without any instability problems. c) Semantic segmentation models must learn long-distance contextual information while retaining high spatial resolution at the output. Existing models achieves this at the cost of computationally expensive and memory exhaustive training/inference. We designed stacked u-nets model which can repeatedly process top-down and bottom-up features. Our smallest model exceeds Resnet-101 performance on PASCAL VOC 2012 by 4.5% IoU with ∼ 7× fewer parameters. Next, we address the problem of learning heterogeneous concepts from internet videos using mined label tags. Given a large number of videos each with multiple concepts and labels, the idea is to teach machines to automatically learn these concepts by leveraging weak labels. We formulate this into a co-clustering problem and developed a novel bayesian non-parametric weakly supervised Indian buffet process model which additionally enforces the paired label prior between concepts. In the final part of this work we consider an inverse approach: learning data priors from a given model. Specifically, we develop numerically efficient algorithm for estimating the log likelihood of data samples from GANs. The approximate log-likelihood function is used for outlier detection and data augmentation for training classifiers

    Essential Speech and Language Technology for Dutch: Results by the STEVIN-programme

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    Computational Linguistics; Germanic Languages; Artificial Intelligence (incl. Robotics); Computing Methodologie

    Graph Processing on GPU

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    Ph.DDOCTOR OF PHILOSOPH

    ICSEA 2021: the sixteenth international conference on software engineering advances

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    The Sixteenth International Conference on Software Engineering Advances (ICSEA 2021), held on October 3 - 7, 2021 in Barcelona, Spain, continued a series of events covering a broad spectrum of software-related topics. The conference covered fundamentals on designing, implementing, testing, validating and maintaining various kinds of software. The tracks treated the topics from theory to practice, in terms of methodologies, design, implementation, testing, use cases, tools, and lessons learnt. The conference topics covered classical and advanced methodologies, open source, agile software, as well as software deployment and software economics and education. The conference had the following tracks: Advances in fundamentals for software development Advanced mechanisms for software development Advanced design tools for developing software Software engineering for service computing (SOA and Cloud) Advanced facilities for accessing software Software performance Software security, privacy, safeness Advances in software testing Specialized software advanced applications Web Accessibility Open source software Agile and Lean approaches in software engineering Software deployment and maintenance Software engineering techniques, metrics, and formalisms Software economics, adoption, and education Business technology Improving productivity in research on software engineering Trends and achievements Similar to the previous edition, this event continued to be very competitive in its selection process and very well perceived by the international software engineering community. As such, it is attracting excellent contributions and active participation from all over the world. We were very pleased to receive a large amount of top quality contributions. We take here the opportunity to warmly thank all the members of the ICSEA 2021 technical program committee as well as the numerous reviewers. The creation of such a broad and high quality conference program would not have been possible without their involvement. We also kindly thank all the authors that dedicated much of their time and efforts to contribute to the ICSEA 2021. We truly believe that thanks to all these efforts, the final conference program consists of top quality contributions. This event could also not have been a reality without the support of many individuals, organizations and sponsors. We also gratefully thank the members of the ICSEA 2021 organizing committee for their help in handling the logistics and for their work that is making this professional meeting a success. We hope the ICSEA 2021 was a successful international forum for the exchange of ideas and results between academia and industry and to promote further progress in software engineering research

    Enabling the Development and Implementation of Digital Twins : Proceedings of the 20th International Conference on Construction Applications of Virtual Reality

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    Welcome to the 20th International Conference on Construction Applications of Virtual Reality (CONVR 2020). This year we are meeting on-line due to the current Coronavirus pandemic. The overarching theme for CONVR2020 is "Enabling the development and implementation of Digital Twins". CONVR is one of the world-leading conferences in the areas of virtual reality, augmented reality and building information modelling. Each year, more than 100 participants from all around the globe meet to discuss and exchange the latest developments and applications of virtual technologies in the architectural, engineering, construction and operation industry (AECO). The conference is also known for having a unique blend of participants from both academia and industry. This year, with all the difficulties of replicating a real face to face meetings, we are carefully planning the conference to ensure that all participants have a perfect experience. We have a group of leading keynote speakers from industry and academia who are covering up to date hot topics and are enthusiastic and keen to share their knowledge with you. CONVR participants are very loyal to the conference and have attended most of the editions over the last eighteen editions. This year we are welcoming numerous first timers and we aim to help them make the most of the conference by introducing them to other participants
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