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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Digital mapping of critical infrastructure : Design of a component data collection method for small-scale power grids

Rapp, Axel January 2023 (has links)
Critical infrastructures (CIs) distributing water, oil, gas, electricity, etc., to community residents and businesses, leverage cyber-physical systems (CPSs) to supervise and control the physical processes that these services entail. Over recent decades, these systems have moved to implement more modern IT-resembling solutions using Supervisory Control and Data Acquisition Systems (SCADA) for increased reliability, scalability, and remote connectivity. This change exposes these highly critical systems to new threats and vulnerabilities. One approach to mitigate the risks faced by these systems is to perform analysis on digital representations in the form of digital models or digital shadows of the CPSs. However, this is not a trivial task in practice. These practical issues are explored in this design science research through the development of a guidance process to perform the data collection necessary to create a static digital model of a small-scale power grid CPS in Sweden. The results show that it is possible to gather information on the CPS components through the four approaches: SCADA system exports, documentation information, CLI scripting, and network scanning. While the artefact presented in this report demonstrates these results, challenges still remain such as a lack of SCADA export tools, reaching the SCADA network with scanning tools in a responsible manner, and accessing insights into the complete documentation held by the organisations. The researcher suggests these topics for future research directions.
62

Efficiency and security in data-driven applications

Zhang, Kaijin, ZHANG 04 June 2018 (has links)
No description available.
63

ILoViT: Indoor Localization via Vibration Tracking

Poston, Jeffrey Duane 23 April 2018 (has links)
Indoor localization remains an open problem in geolocation research, and once this is solved the localization enables counting and tracking of building occupants. This information is vital in an emergency, enables occupancy-optimized heating or cooling, and assists smart buildings in tailoring services for occupants. Unfortunately, two prevalent technologies---GPS and cellular-based positioning---perform poorly indoors due to attenuation and multipath from the building. To address this issue, the research community devised many alternatives for indoor localization (e.g., beacons, RFID tags, Wi-Fi fingerprinting, and UWB to cite just a few examples). A drawback with most is the requirement for those being located to carry a properly-configured device at all times. An alternative based on computer vision techniques poses significant privacy concerns due to cameras recording building occupants. By contrast, ILoViT research makes novel use of accelerometers already present in some buildings. These sensors were originally intended to monitor structural health or to study structural dynamics. The key idea is that when a person's footstep-generated floor vibrations can be detected and located then it becomes possible to locate persons moving within a building. Vibration propagation in buildings has complexities not encountered by acoustic or radio wave propagation in air; thus, conventional localization algorithms are inadequate. ILoVIT algorithms account for these conditions and have been demonstrated in a public building to provide sub-meter accuracy. Localization provides the foundation for counting and tracking, but providing these additional capabilities confronts new challenges. In particular, how does one determine the correct association of footsteps to the person making them? The ILoViT research created two methods for solving the data association problem. One method only provides occupancy counting but has modest, polynomial time complexity. The other method draws inspiration from prior work in the radar community on the multi-target tracking problem, specifically drawing from the multiple hypothesis tracking strategy. This dissertation research makes new enhancements to this tracking strategy to account for human gait and characteristics of footstep-derived multilateration. The Virginia Polytechnic Institute and State University's College of Engineering recognized this dissertation research with the Paul E. Torgersen Graduate Student Research Excellence Award. / Ph. D.
64

Intrusion Detection of Flooding DoS Attacks on Emulated Smart Meters

Akbar, Yousef M. A. H. 11 May 2020 (has links)
The power grid has changed a great deal from what has been generally viewed as a traditional power grid. The modernization of the power grid has seen an increase in the integration and incorporation of computing and communication elements, creating an interdependence of both physical and cyber assets of the power grid. The fast-increasing connectivity has transformed the grid from what used to be primarily a physical system into a Cyber- Physical System (CPS). The physical elements within a power grid are well understood by power engineers; however, the newly deployed cyber aspects are new to most researchers and operators in this field. The new computing and communications structure brings new vulnerabilities along with all the benefits it provides. Cyber security of the power grid is critical due to the potential impact it can make on the community or society that relies on the critical infrastructure. These vulnerabilities have already been exploited in the attack on the Ukrainian power grid, a highly sophisticated, multi-layered attack which caused large power outages for numerous customers. There is an urgent need to understand the cyber aspects of the modernized power grid and take the necessary precautions such that the security of the CPS can be better achieved. The power grid is dependent on two main cyber infrastructures, i.e., Supervisory Control And Data Acquisition (SCADA) and Advanced Metering Infrastructure (AMI). This thesis investigates the AMI in power grids by developing a testbed environment that can be created and used to better understand and develop security strategies to remove the vulnerabilities that exist within it. The testbed is to be used to conduct and implement security strategies, i.e., an Intrusion Detections Systems (IDS), creating an emulated environment to best resemble the environment of the AMI system. A DoS flooding attack and an IDS are implemented on the emulated testbed to show the effectiveness and validate the performance of the emulated testbed. / M.S. / The power grid is becoming more digitized and is utilizing information and communication technologies more, hence the smart grid. New systems are developed and utilized in the modernized power grid that directly relies on new communication networks. The power grid is becoming more efficient and more effective due to these developments, however, there are some considerations to be made as for the security of the power grid. An important expectation of the power grid is the reliability of power delivery to its customers. New information and communication technology integration brings rise to new cyber vulnerabilities that can inhibit the functionality of the power grid. A coordinated cyber-attack was conducted against the Ukrainian power grid in 2015 that targeted the cyber vulnerabilities of the system. The attackers made sure that the grid operators were unable to observe their system being attacked via Denial of Service attacks. Smart meters are the digitized equivalent of a traditional energy meter, it wirelessly communicates with the grid operators. An increase in deployment of these smart meters makes it such that we are more dependent on them and hence creating a new vulnerability for an attack. The smart meter integration into the power grid needs to be studied and carefully considered for the prevention of attacks. A testbed is created using devices that emulate the smart meters and a network is established between the devices. The network was attacked with a Denial of Service attack to validate the testbed performance, and an Intrusion detection method was developed and applied onto the testbed to prove that the testbed created can be used to study and develop methods to cover the vulnerabilities present.
65

REACHABILITY ANALYSIS OF HUMAN-IN-THE-LOOP SYSTEMS USING GAUSSIAN MIXTURE MODEL WITH SIDE INFORMATION

Cheng-Han Yang (18521940) 08 May 2024 (has links)
<p dir="ltr">In the context of a Human-in-the-Loop (HITL) system, the accuracy of reachability analysis plays a significant role in ensuring the safety and reliability of HITL systems. In addition, one can avoid unnecessary conservativeness by explicitly considering human control behavior compared to those methods that rely on the system dynamics alone. One possible approach is to use a Gaussian Mixture Model (GMM) to encode human control behavior using the Expectation-Maximization (EM) algorithm. However, relatively few works consider the admissible control input ranges due to physical limitations when modeling human control behavior. This could make the following reachability analysis overestimate the system's capability, thereby affecting the performance of the HITL system. To address this issue, this work presents a constrained stochastic reachability analysis algorithm that can explicitly account for the admissible control input ranges. By confining the ellipsoidal confidence region of each Gaussian component using Sequential Quadratic Programming (SQP), we probabilistically constrain the GMM as well as the corresponding stochastic reachable sets. A comprehensive mathematical analysis of how the constrained GMM can affect the stochastic reachable sets is provided in this work. Finally, the proposed stochastic reachability analysis algorithm is validated via an illustrative numerical example.</p>
66

Framtidens industri: Från visionen Industri 4.0 idag till verkligheten imorgon : En fallstudie på HordaGruppen AB

Ekelöf, Alexander, Stålring, Mikaela January 2016 (has links)
Företags framtid ligger i dess egna händer; beroende på hur väl de anpassar sig till nya förutsättningar i alla dess former så kommer vissa att överleva medan andra går i graven. Under flera hundra år har utvecklingen inom industrin medfört att företag kommit och gått. Idag står vi enligt flera inför randen till en ny teknisk era med en fjärde industriell revolution som följd, Industri 4.0. Vi har en evolution mot en mer automatiserad tillverkningsindustri där allt fler moment sker utan en människas händer bakom spakarna. Industri 4.0 ses av många som en vision om hur framtiden kommer att se ut inom tillverkningsindustrin. Många av de idéer samt teknik som finns inom denna vision går att ta del av redan idag och möjligheterna till att förbereda sig för framtiden finns redan och det gäller att så snabbt som möjligt börja ställa om för detta. I takt med att industrin och dess konkurrens förändras kommer kraven på kvalité öka samtidigt som tillverkningen måste blir mer resurseffektiv. Området är mycket viktigt att belysa då det är ett nytt område där det tidigare inte skett mycket forskning. Att belysa detta område kan även komma att inspirera andra till ytterligare studier inom området och främja utvecklingen för fler företag än endast fallföretaget i denna studie: HordaGruppen. Syftet med studien har varit att inledningsvis få en förståelse för vilka tankar och idéer om framtiden som finns inom industrin idag för att senare kunna testa lösningar baserade på dessa idéer på några befintliga problem inom HordaGruppen, vars verksamhet finns inom plastindustrin. Lösningarna kan ses som de första stegen mot Industri 4.0 för att underlätta för företaget ifråga inför en framtida utveckling och ger även företaget möjlighet att börja samla in data kring processen, vilket i framtiden ger företag som HordaGruppen en fördel gentemot konkurrenter som påbörjar sin omställning senare. Utgångspunkten för studien har varit en kvalitativ studie med aktionsforskning och fallstudie som angreppsätt. Fallstudien har utförts genom en intervju med John Lejon, affärsutvecklare på HordaGruppen och en öppen diskussion med produktionsledare Valdet Berisha angående maskinen som är fokuserad på. Data till studien har erhållits genom artiklar skrivna inom området samt en intervju med grundaren till ett stort statligt projekt i Tyskland, Philipp Ramin, där de startat ett innovationscentrum för Industri 4.0. Resultatet i rapporten är att med hjälp av dagens teknik går det att ta de första stegen mot visionen Industri 4.0. All teknik finns självklart inte, men med hjälp av den teknik som finns idag kan olika företag inom tillverkningsindustrin dra fördelar av att starta omställningen mot Industri 4.0 redan idag. / The future of industry is in companies own hands. Today we are going to a more automated manufacturing industry where human beings are less involved and it is more crucial than ever before to adapt to new changes in the industry and technology. Internet of things and cyber physical systems are becoming a bigger part of our lives. This case study on HordaGruppen is focused on how HordaGruppen from the plastic industry can develop with some ideas from the vision Industry 4.0 in order to ensure the quality of the product. Most of the technology needed for Industry 4.0 is available today and there is no reason not to start using it. The study will introduce to Industry 4.0 and the basic ideas that the vision stands for and then try to define and solve some problems within one machine in one of their plants. The results presented in this study shows that using sensors and other technology available today you can take the first steps towards Industry 4.0.
67

Intégration de modèles de réseaux IP à un multi-modèle DEVS, pour la co-simulation de systèmes cyber-physiques / Integration of IP network models to DEVS multi-models, for cyber-physical system co-simulations

Vaubourg, Julien 25 April 2017 (has links)
Modéliser et simuler (M&S) un système cyber-physique (SCP) peut nécessiter de représenter des éléments provenant de trois domaines d'expertise à la fois : systèmes physiques, systèmes d'informations et réseaux de communication (IP). Le simulateur universel disposant de toutes les compétences nécessaires n'existant pas, il est possible de regrouper des modèles issus des différentes communautés, à l'aide d'un multi-modèle. Les défis sont alors 1) intégrer toute l'hétérogénéité du multi-modèle (formalismes, représentations, implémentations), 2) intégrer des modèles IP de façon à ce qu'ils soient en capacité de représenter le transport de données applicatives produites par des modèles externes et 3) les intégrer de façon à ce qu'ils puissent se compléter, pour représenter ensemble les réseaux IP parfois hétérogènes d'un SCP. Pour parvenir à répondre à ces défis, nous nous inscrivons dans la continuité des travaux de M&S autour de MECSYCO, une plateforme de co-simulation basée sur la notion de wrapping DEVS. Nous proposons de définir un cadre général pour réussir à wrapper en DEVS des modèles IP, avec 1) une structuration des différents niveaux de problèmes pour l'intégration de modèles IP dans une co-simulation (délimitation des objectifs et contraintes du wrapping), et 2) une proposition de stratégie de wrapping DEVS de modèles IP et leurs simulateurs. Nous évaluerons notre approche à travers la démonstration de l'intégration de deux simulateurs IP populaires, et d'exemples concrets de M&S de SCP (avec notamment une interconnexion de modèles entre NS-3 et OMNeT++/INET, et une application industrielle utilisée par EDF R&D) / Modeling and simulation (M&S) of cyber-physical systems (CPS) can require representing components from three expertise fields: physics, information systems, and communication networks (IP). There is no universal simulator with all of the required skills, but we can gather and interconnect models provided by the communities, with a multi-model. The challenges are 1) integrating all heterogeneities in a multi-model (formalisms, representations, implementations), 2) integrating IP models in a way enabling them to represent the transport of application data produced by external models, and 3) integrating IP models in a way enabling them to complete each other, to be able to represent CPS heterogeneous IP networks. In order to meet these challenges, we relied our solution on the works around MECSYCO, a co-simulation platform based on the DEVS wrapping principle. We propose to define a comprehensive framework enabling to achieve DEVS wrapping of IP models, with 1) a structuration of different issue levels when integrating IP models in a co-simulation (goals and constraints of the wrapping) and 2) a proposition of a DEVS wrapping strategy for IP models and their simulators. We propose some evaluations of our approach, through the integration of two popular IP simulators, and concrete examples of CPS M&S (inter alia, with an example of a models interconnection between NS-3 and OMNeT++/INET, and an industrial application used by EDF R&D)
68

Analysis and coordination of mixed-criticality cyber-physical systems

Maurer, Simon January 2018 (has links)
A Cyber-physical System (CPS) can be described as a network of interlinked, concurrent computational components that interact with the physical world. Such a system is usually of reactive nature and must satisfy strict timing requirements to guarantee a correct behaviour. The components can be of mixed-criticality which implies different progress models and communication models, depending whether the focus of a component lies on predictability or resource efficiency. In this dissertation I present a novel approach that bridges the gap between stream processing models and Labelled Transition Systems (LTSs). The former offer powerful tools to describe concurrent systems of, usually simple, components while the latter allow to describe complex, reactive, components and their mutual interaction. In order to achieve the bridge between the two domains I introduce the novel LTS Synchronous Interface Automaton (SIA) that allows to model the interaction protocol of a process via its interface and to incrementally compose simple processes into more complex ones while preserving the system properties. Exploiting these properties I introduce an analysis to identify permanent blocking situations in a network of composed processes. SIAs are wrapped by the novel component-based coordination model Process Network with Synchronous Communication (PNSC) that allows to describe a network of concurrent processes where multiple communication models and the co-existence and interaction of heterogeneous processes is supported due to well defined interfaces. The work presented in this dissertation follows a holistic approach which spans from the theory of the underlying model to an instantiation of the model as a novel coordination language, called Streamix. The language uses network operators to compose networks of concurrent processes in a structured and hierarchical way. The work is validated by a prototype implementation of a compiler and a Run-time System (RTS) that allows to compile a Streamix program and execute it on a platform with support for ISO C, POSIX threads, and a Linux operating system.
69

Simulation temps-réel distribuée de modèles numériques : application au groupe motopropulseur / Distributed real-time simulation of numerical models : application to power-train

Ben Khaled-El Feki, Abir 27 May 2014 (has links)
De nos jours, la validation des unités de contrôle électronique ECU se fonde généralement sur la simulationHardware-In-the-Loop où les systèmes physiques qui manquent sont modélisés à l’aide deséquations différentielles hybrides. La complexité croissante de ce type de modèles rend le compromisentre le temps de calcul et la précision de la simulation difficile à satisfaire. Cette thèse étudie et proposedes méthodes d’analyse et d’expérimentation destinées à la co-simulation temps-réel ferme de modèlesdynamiques hybrides. Elle vise notamment à définir des solutions afin d’exploiter plus efficacement leparallélisme fourni par les architectures multi-coeurs en utilisant de nouvelles méthodes et paradigmesde l’allocation des ressources. La première phase de la thèse a étudié la possibilité d’utiliser des méthodesd’intégration numérique permettant d’adapter l’ordre comme la taille du pas de temps ainsi quede détecter les événements et ceci dans le contexte de la co-simulation modulaire avec des contraintestemps-réel faiblement dures. De plus, l’ordre d’exécution des différents modèles a été étudié afin dedémontrer l’influence du respect des dépendances de données entre les modèles couplés sur les résultatsde la simulation. Nous avons proposé pour cet objectif, une nouvelle méthode de co-simulationqui permet le parallélisme complet entre les modèles impliquant une accélération supra-linéaire sanspour autant ajouter des erreurs liées à l’ordre d’exécution. Enfin, les erreurs de retard causées par lataille de pas de communication entre les modèles ont été améliorées grâce à une nouvelle méthoded’extrapolation par contexte des signaux d’entrée. Toutes les approches proposées visent de manièreconstructive à améliorer la vitesse de simulation afin de respecter les contraintes temps-réel, tout engardant la qualité et la précision des résultats de simulation sous contrôle. Ces méthodes ont été validéespar plusieurs essais et expériences sur un modèle de moteur à combustion interne et intégrées àun prototype du logiciel xMOD. / Nowadays the validation of Electronic Control Units ECUs generally relies on Hardware-in-The-Loopsimulation where the lacking physical systems are modeled using hybrid differential equations. Theincreasing complexity of this kind of models makes the trade-off between time efficiency and the simulationaccuracy hard to satisfy. This thesis investigates and proposes some analytical and experimentalmethods towards weakly-hard real-time co-simulation of hybrid dynamical models. It seeks in particularto define solutions in order to exploit more efficiently the parallelism provided by multi-core architecturesusing new methods and paradigms of resource allocation. The first phase of the thesis studied the possibilityof using step-size and order control numerical integration methods with events detection in thecontext of real-time modular co-simulation when the time constraints are considered weakly-hard. Moreover,the execution order of the different models was studied to show the influence of keeping or not thedata dependencies between coupled models on the simulation results. We proposed for this aim a newmethod of co-simulation that allows the full parallelism between models implying supra-linear speed-upswithout adding errors related to their execution order. Finally, the delay errors due to the communicationstep-size between the models were improved thanks to a proposed context-based inputs extrapolation.All proposed approaches target constructively to enhance the simulation speed for the compliance toreal-time constraints while keeping the quality and accuracy of simulation results under control and theyare validated through several test and experiments on an internal combustion engine model and integratedto a prototype version of the xMOD software.
70

DEEP LEARNING FOR SECURING CRITICAL INFRASTRUCTURE WITH THE EMPHASIS ON POWER SYSTEMS AND WIRELESS COMMUNICATION

Gihan janith mendis Imbulgoda liyangahawatte (10488467) 27 April 2023 (has links)
<p><em>Imbulgoda Liyangahawatte, Gihan Janith Mendis Ph.D., Purdue University, May</em></p> <p><em>2023. Deep learning for securing critical infrastructure with the emphasis on power</em></p> <p><em>systems and wireless communication. Major Professor: Dr. Jin Kocsis.</em></p> <p><br></p> <p><em>Critical infrastructures, such as power systems and communication</em></p> <p><em>infrastructures, are of paramount importance to the welfare and prosperity of</em></p> <p><em>modern societies. Therefore, critical infrastructures have a high vulnerability to</em></p> <p><em>attacks from adverse parties. Subsequent to the advancement of cyber technologies,</em></p> <p><em>such as information technology, embedded systems, high-speed connectivity, and</em></p> <p><em>real-time data processing, the physical processes of critical infrastructures are often</em></p> <p><em>monitored and controlled through cyber systems. Therefore, modern critical</em></p> <p><em>infrastructures are often viewed as cyber-physical systems (CPSs). Incorporating</em></p> <p><em>cyber elements into physical processes increases efficiency and control. However, it</em></p> <p><em>also increases the vulnerability of the systems to potential cybersecurity threats. In</em></p> <p><em>addition to cyber-level attacks, attacks on the cyber-physical interface, such as the</em></p> <p><em>corruption of sensing data to manipulate physical operations, can exploit</em></p> <p><em>vulnerabilities in CPSs. Research on data-driven security methods for such attacks,</em></p> <p><em>focusing on applications related to electrical power and wireless communication</em></p> <p><em>critical infrastructure CPSs, are presented in this dissertation. As security methods</em></p> <p><em>for electrical power systems, deep learning approaches were proposed to detect</em></p> <p><em>adversarial sensor signals targeting smart grids and more electric aircraft.</em></p> <p><em>Considering the security of wireless communication systems, deep learning solutions</em></p> <p><em>were proposed as an intelligent spectrum sensing approach and as a primary user</em></p> <p><em>emulation (PUE) attacks detection method on the wideband spectrum. The recent</em></p> <p><em>abundance of micro-UASs can enable the use of weaponized micro-UASs to conduct</em></p> <p><em>physical attacks on critical infrastructures. As a solution for this, the radio</em></p> <p><em>frequency (RF) signal-analyzing deep learning method developed for spectrum</em></p> <p><em>sensing was adopted to realize an intelligent radar system for micro-UAS detection.</em></p> <p><em>This intelligent radar can be used to provide protection against micro-UAS-based</em></p> <p><em>physical attacks on critical infrastructures.</em></p>

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