291 research outputs found

    Distributed anomaly detection models for industrial wireless sensor networks

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    Wireless Sensor Networks (WSNs) are firmly established as an integral technology that enables automation and control through pervasive monitoring for many industrial applications. These range from environmental applications and healthcare applications to major industrial monitoring applications such as infrastructure and structural monitoring. The key features that are common to such applications can be noted as involving large amounts of data, consisting of dynamic observation environments, non-homogeneous data distributions with evolving patterns and sensing functionality leading to data-driven control. Also in most industrial applications a major requirement is to have near real-time decision support. Accordingly there is a vital need to have a secure continuous and reliable sensing mechanism in integrated WSNs where integrity of the data is assured. However, in practice WSNs are vulnerable to different security attacks, faults and malfunction due to inherent resource constraints, openly commoditised wireless technologies employed and naive modes of implementation. Misbehaviour resulting from such threats manifest as anomalies in the sensed data streams in critically compromising the systems. Therefore, it is vital that effective techniques are introduced in accurately detecting anomalies and assuring the integrity of the data. This research focuses on investigating such models for large scale industrial wireless sensor networks. Focusing on achieving an anomaly detection framework that is adaptable and scalable, a hierarchical data partitioning approach with fuzzy data modelling is introduced first. In this model unsupervised data partitioning is performed in a distributed manner by adapting fuzzy c-means clustering in an incremental model over a hierarchical node topology. It is found that non-parametric and non-probabilistic determination of anomalies can be done by evaluating the fuzzy membership scores and inter-cluster distances adaptively over the node hierarchy. Considering heterogeneous data distributions with evolving patterns, a granular anomaly detection model that uses an entropy criterion to dynamically partition the data is proposed next. This successfully overcomes the issue of determining the proper number of expected clusters in a dynamic manner. In this approach the data is partitioned on to different cohesive regions using cumulative point-wise entropy directly. The effect of differential density distributions when relying on an entropy criterion is mitigated by introducing an average relative density measure to segregate isolated outliers prior to the partitioning. The combination of these two factors is shown to be significantly successful in determining anomalies adaptively in a fully dynamic manner. The need for near real-time anomaly evaluation is focused next on this thesis. Building upon the entropy based data partitioning model that is also proposed, a Point-of-View (PoV) entropy evaluation model is developed next. This employs an incremental data processing model as opposed to batch-wise data processing. Three unique points-of-view are introduced as the reference points over which point-wise entropy is computed in evaluating its relative change as the data streams evolve. Overall this thesis proposes efficient unsupervised anomaly detection models that employ distributed in-network data processing for accurate determination of anomalies. The resource constrained environment is taken in to account in each of the models with innovations made to achieve non-parametric and non-probabilistic detection

    Network anomaly detection research: a survey

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    Data analysis to identifying attacks/anomalies is a crucial task in anomaly detection and network anomaly detection itself is an important issue in network security. Researchers have developed methods and algorithms for the improvement of the anomaly detection system. At the same time, survey papers on anomaly detection researches are available. Nevertheless, this paper attempts to analyze futher and to provide alternative taxonomy on anomaly detection researches focusing on methods, types of anomalies, data repositories, outlier identity and the most used data type. In addition, this paper summarizes information on application network categories of the existing studies

    End-to-end anomaly detection in stream data

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    Nowadays, huge volumes of data are generated with increasing velocity through various systems, applications, and activities. This increases the demand for stream and time series analysis to react to changing conditions in real-time for enhanced efficiency and quality of service delivery as well as upgraded safety and security in private and public sectors. Despite its very rich history, time series anomaly detection is still one of the vital topics in machine learning research and is receiving increasing attention. Identifying hidden patterns and selecting an appropriate model that fits the observed data well and also carries over to unobserved data is not a trivial task. Due to the increasing diversity of data sources and associated stochastic processes, this pivotal data analysis topic is loaded with various challenges like complex latent patterns, concept drift, and overfitting that may mislead the model and cause a high false alarm rate. Handling these challenges leads the advanced anomaly detection methods to develop sophisticated decision logic, which turns them into mysterious and inexplicable black-boxes. Contrary to this trend, end-users expect transparency and verifiability to trust a model and the outcomes it produces. Also, pointing the users to the most anomalous/malicious areas of time series and causal features could save them time, energy, and money. For the mentioned reasons, this thesis is addressing the crucial challenges in an end-to-end pipeline of stream-based anomaly detection through the three essential phases of behavior prediction, inference, and interpretation. The first step is focused on devising a time series model that leads to high average accuracy as well as small error deviation. On this basis, we propose higher-quality anomaly detection and scoring techniques that utilize the related contexts to reclassify the observations and post-pruning the unjustified events. Last but not least, we make the predictive process transparent and verifiable by providing meaningful reasoning behind its generated results based on the understandable concepts by a human. The provided insight can pinpoint the anomalous regions of time series and explain why the current status of a system has been flagged as anomalous. Stream-based anomaly detection research is a principal area of innovation to support our economy, security, and even the safety and health of societies worldwide. We believe our proposed analysis techniques can contribute to building a situational awareness platform and open new perspectives in a variety of domains like cybersecurity, and health

    An Overview of Automotive Service-Oriented Architectures and Implications for Security Countermeasures

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    New requirements from the customers\u27 and manufacturers\u27 point of view such as adding new software functions during the product life cycle require a transformed architecture design for future vehicles. The paradigm of signal-oriented communication established for many years will increasingly be replaced by service-oriented approaches in order to increase the update and upgrade capability. In this article, we provide an overview of current protocols and communication patterns for automotive architectures based on the service-oriented architecture (SOA) paradigm and compare them with signal-oriented approaches. Resulting challenges and opportunities of SOAs with respect to information security are outlined and discussed. For this purpose, we explain different security countermeasures and present a state of the section of automotive approaches in the fields of firewalls, Intrusion Detection Systems (IDSs) and Identity and Access Management (IAM). Our final discussion is based on an exemplary hybrid architecture (signal- and service-oriented) and examines the adaptation of existing security measures as well as their specific security features

    Sustainable Agriculture and Advances of Remote Sensing (Volume 2)

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    Agriculture, as the main source of alimentation and the most important economic activity globally, is being affected by the impacts of climate change. To maintain and increase our global food system production, to reduce biodiversity loss and preserve our natural ecosystem, new practices and technologies are required. This book focuses on the latest advances in remote sensing technology and agricultural engineering leading to the sustainable agriculture practices. Earth observation data, in situ and proxy-remote sensing data are the main source of information for monitoring and analyzing agriculture activities. Particular attention is given to earth observation satellites and the Internet of Things for data collection, to multispectral and hyperspectral data analysis using machine learning and deep learning, to WebGIS and the Internet of Things for sharing and publication of the results, among others

    How Much Training Data Is Enough? A Case Study for HTTP Anomaly-Based Intrusion Detection

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    Most anomaly-based intrusion detectors rely on models that learn from training datasets whose quality is crucial in their performance. Albeit the properties of suitable datasets have been formulated, the influence of the dataset size on the performance of the anomaly-based detector has received scarce attention so far. In this work, we investigate the optimal size of a training dataset. This size should be large enough so that training data is representative of normal behavior, but after that point, collecting more data may result in unnecessary waste of time and computational resources, not to mention an increased risk of overtraining. In this spirit, we provide a method to find out when the amount of data collected at the production environment is representative of normal behavior in the context of a detector of HTTP URI attacks based on 1-grammar. Our approach is founded on a set of indicators related to the statistical properties of the data. These indicators are periodically calculated during data collection, producing time series that stabilize when more training data is not expected to translate to better system performance, which indicates that data collection can be stopped.We present a case study with real-life datasets collected at the University of Seville (Spain) and a public dataset from the University of Saskatchewan. The application of our method to these datasets showed that more than 42% of one trace, and almost 20% of another were unnecessarily collected, thereby showing that our proposed method can be an efficient approach for collecting training data at the production environment.This work was supported in part by the Corporación Tecnológica de Andalucía and the University of Seville through the Projects under Grant CTA 1669/22/2017, Grant PI-1786/22/2018, and Grant PI-1736/22/2017

    New Fundamental Technologies in Data Mining

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    The progress of data mining technology and large public popularity establish a need for a comprehensive text on the subject. The series of books entitled by "Data Mining" address the need by presenting in-depth description of novel mining algorithms and many useful applications. In addition to understanding each section deeply, the two books present useful hints and strategies to solving problems in the following chapters. The contributing authors have highlighted many future research directions that will foster multi-disciplinary collaborations and hence will lead to significant development in the field of data mining

    Advances in Computer Recognition, Image Processing and Communications, Selected Papers from CORES 2021 and IP&C 2021

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    As almost all human activities have been moved online due to the pandemic, novel robust and efficient approaches and further research have been in higher demand in the field of computer science and telecommunication. Therefore, this (reprint) book contains 13 high-quality papers presenting advancements in theoretical and practical aspects of computer recognition, pattern recognition, image processing and machine learning (shallow and deep), including, in particular, novel implementations of these techniques in the areas of modern telecommunications and cybersecurity

    Improving Access and Mental Health for Youth Through Virtual Models of Care

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    The overall objective of this research is to evaluate the use of a mobile health smartphone application (app) to improve the mental health of youth between the ages of 14–25 years, with symptoms of anxiety/depression. This project includes 115 youth who are accessing outpatient mental health services at one of three hospitals and two community agencies. The youth and care providers are using eHealth technology to enhance care. The technology uses mobile questionnaires to help promote self-assessment and track changes to support the plan of care. The technology also allows secure virtual treatment visits that youth can participate in through mobile devices. This longitudinal study uses participatory action research with mixed methods. The majority of participants identified themselves as Caucasian (66.9%). Expectedly, the demographics revealed that Anxiety Disorders and Mood Disorders were highly prevalent within the sample (71.9% and 67.5% respectively). Findings from the qualitative summary established that both staff and youth found the software and platform beneficial
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