461 research outputs found

    Review on Active and Passive Remote Sensing Techniques for Road Extraction

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    Digital maps of road networks are a vital part of digital cities and intelligent transportation. In this paper, we provide a comprehensive review on road extraction based on various remote sensing data sources, including high-resolution images, hyperspectral images, synthetic aperture radar images, and light detection and ranging. This review is divided into three parts. Part 1 provides an overview of the existing data acquisition techniques for road extraction, including data acquisition methods, typical sensors, application status, and prospects. Part 2 underlines the main road extraction methods based on four data sources. In this section, road extraction methods based on different data sources are described and analysed in detail. Part 3 presents the combined application of multisource data for road extraction. Evidently, different data acquisition techniques have unique advantages, and the combination of multiple sources can improve the accuracy of road extraction. The main aim of this review is to provide a comprehensive reference for research on existing road extraction technologies.Peer reviewe

    Deep learning-based vessel detection from very high and medium resolution optical satellite images as component of maritime surveillance systems

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    This thesis presents an end-to-end multiclass vessel detection method from optical satellite images. The proposed workflow covers the complete processing chain and involves rapid image enhancement techniques, the fusion with automatic identification system (AIS) data, and the detection algorithm based on convolutional neural networks (CNN). The algorithms presented are implemented in the form of independent software processors and integrated in an automated processing chain as part of the Earth Observation Maritime Surveillance System (EO-MARISS).In der vorliegenden Arbeit wird eine Methode zur Detektion von Schiffen unterschiedlicher Klassen in optischen Satellitenbildern vorgestellt. Diese gliedert sich in drei aufeinanderfolgende Funktionen: i) die Bildbearbeitung zur Verbesserung der Bildeigenschaften, ii) die Datenfusion mit den Daten des Automatischen Identifikation Systems (AIS) und iii) dem auf „Convolutional Neural Network“ (CNN) basierenden Detektionsalgorithmus. Die vorgestellten Algorithmen wurden in Form eigenständiger Softwareprozessoren implementiert und als Teil des maritimen Erdbeobachtungssystems integriert

    AI/ML-based support of satellite sensing for cloud cover classification

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    Cyber Security

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    This open access book constitutes the refereed proceedings of the 16th International Annual Conference on Cyber Security, CNCERT 2020, held in Beijing, China, in August 2020. The 17 papers presented were carefully reviewed and selected from 58 submissions. The papers are organized according to the following topical sections: access control; cryptography; denial-of-service attacks; hardware security implementation; intrusion/anomaly detection and malware mitigation; social network security and privacy; systems security

    Personalization platform for multimodal ubiquitous computing applications

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    Dissertação para obtenção do Grau de Mestre em Engenharia InformáticaWe currently live surrounded by a myriad of computing devices running multiple applications. In general, the user experience on each of those scenarios is not adapted to each user’s specific needs, without personalization and integration across scenarios. Moreover, developers usually do not have the right tools to handle that in a standard and generic way. As such, a personalization platform may provide those tools. This kind of platform should be readily available to be used by any developer. Therefore, it must be developed to be available over the Internet. With the advances in IT infrastructure, it is now possible to develop reliable and scalable services running on abstract and virtualized platforms. Those are some of the advantages of cloud computing, which offers a model of utility computing where customers are able to dynamically allocate the resources they need and are charged accordingly. This work focuses on the creation of a cloud-based personalization platform built on a previously developed generic user modeling framework. It provides user profiling and context-awareness tools to third-party developers. A public display-based application was also developed. It provides useful information to students, teachers and others in a university campus as they are detected by Bluetooth scanning. It uses the personalization platform as the basis to select the most relevant information in each situation, while a mobile application was developed to be used as an input mechanism. A user study was conducted to assess the usefulness of the application and to validate some design choices. The results were mostly positive

    Improved Tracking with IEEE 802.11 and Location Fingerprinting

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    In recent years, location-based services have become increasingly important for our daily lives. To estimate a user’s position, these days mainly the Global Positioning System (GPS) is used. In situations where GPS in unavailable, location fingerprinting with the help of IEEE 802.11 has proven as a viable alternative. However, the latter still suffers from some problems that impede a widespread use. These problems firstly are identified in this thesis, and secondly solutions to the different issues are introduced and evaluated. The covered topics contain means to improve the positioning accuracy of location fingerprinting with IEEE 802.11, algorithms to greatly decrease the effort that is necessary to set up a fingerprint database, and ways to estimate the error that has to be expected when estimating a position with IEEE 802.11 and location fingerprinting. Furthermore, the thesis covers problems that occur when estimating the position of a mobile user with IEEE 802.11 and location fingerprinting. Finally, an overview of application scenarios for the given algorithms is presented and a conclusion is given

    SAR Remote Sensing of Canadian Coastal Waters using Total Variation Optimization Segmentation Approaches

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    The synthetic aperture radar (SAR) onboard Earth observing satellites has been acknowledged as an integral tool for many applications in monitoring the marine environment. Some of these applications include regional sea-ice monitoring and detection of illegal or accidental oil discharges from ships. Nonetheless, a practicality of the usage of SAR images is greatly hindered by the presence of speckle noises. Such noise must be eliminated or reduced to be utilized in real-world applications to ensure the safety of the marine environment. Thus this thesis presents a novel two-phase total variation optimization segmentation approach to tackle such a challenging task. In the total variation optimization phase, the Rudin-Osher-Fatemi total variation model was modified and implemented iteratively to estimate the piecewise smooth state by minimizing the total variation constraints. In the finite mixture model classification phase, an expectation-maximization method was performed to estimate the final class likelihoods using a Gaussian mixture model. Then a maximum likelihood classification technique was utilized to obtain the final segmented result. For its evaluation, a synthetic image was used to test its effectiveness. Then it was further applied to two distinct real SAR images, X-band COSMO-SkyMed imagery containing verified oil-spills and C-band RADARSAT-2 imagery mainly containing two different sea-ice types to confirm its robustness. Furthermore, other well-established methods were compared with the proposed method to ensure its performance. With the advantage of a short processing time, the visual inspection and quantitative analysis including kappa coefficients and F1 scores of segmentation results confirm the superiority of the proposed method over other existing methods

    Cyber Security

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    This open access book constitutes the refereed proceedings of the 16th International Annual Conference on Cyber Security, CNCERT 2020, held in Beijing, China, in August 2020. The 17 papers presented were carefully reviewed and selected from 58 submissions. The papers are organized according to the following topical sections: access control; cryptography; denial-of-service attacks; hardware security implementation; intrusion/anomaly detection and malware mitigation; social network security and privacy; systems security

    Deep Learning-based Vessel Detection from Very High and Medium Resolution Optical Satellite Images as Component of Maritime Surveillance Systems

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    Today vessel detection from remote sensing images is increasingly becoming a crucial component in maritime surveillance applications. The increasing number of very high and medium resolution (VHR and MR) optical satellites shortens the revisit time as it was never before. This makes the technology especially attractive for a variety of maritime monitoring tasks. Nevertheless, it is quite a challenge to perform object detection on enormous large satellite images that cover several hundreds of square kilometers and derive results under near real time constraints. This thesis presents an end-to-end multiclass vessel detection method from optical satellite images. The proposed workflow covers the complete processing chain and involves rapid image enhancement techniques, the fusion with automatic identification system (AIS) data, and the detection algorithm based on convolutional neural networks (CNN). To train the CNNs, two versions of training datasets were generated. The VHR training dataset was produced from the set of WorldView-[1-3] and GeoEye-1 images and contains about 40 000 of uniquely annotated vessels divided into 14 different classes. The MR training dataset was generated from the set of Landsat-8 images and contains about 14 000 of uniquely annotated vessels of 7 different classes. The algorithms presented are implemented in the form of independent software processors and integrated in an automated processing chain as part of the Earth Observation Maritime Surveillance System (EO-MARISS). The solution developed from the methods presented has proven its usability within different projects and is used and further developed at the ground station of the German Aerospace Center (DLR) in Neustrelitz
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