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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.
1

Classification of and resilience to cyber-attacks on cyber-physical systems

Lyn, Kevin G. 21 September 2015 (has links)
The growing connectivity of cyber-physical systems (CPSes) has led to an increased concern over the ability of cyber-attacks to inflict physical damage. Current cybersecurity measures focus on preventing attacks from penetrating control supervisory networks. These reactive techniques, however, are often plagued with vulnerabilities and zero-day exploits. Embedded processors in CPS field devices often possess little security of their own, and are easily exploited once the network is penetrated. In response, researchers at Georgia Tech and Virginia Tech have proposed a Trustworthy Autonomic Interface Guardian Architecture (TAIGA), which monitors communication between the embedded controller and physical process. This autonomic architecture provides the physical process with a last line of defense against cyber-attacks by switching process control to a trusted backup controller if an attack causes a system specification violation. This thesis focuses on classifying the effects of cyberattacks on embedded controllers, evaluating TAIGA’s resilience against these attacks, and determining the applicability of TAIGA to other CPSes. This thesis identifies four possible outcomes of a cyber-attack on a CPS embedded processor. We then evaluate TAIGA’s mechanisms to defend against those attack outcomes, and verify TAIGA satisfies the listed trust requirements. Next, we discuss an implementation and the experimental results of TAIGA on a hazardous cargo transportation robot. Then, by making various modifications to the setup configuration, we are able to explore TAIGA’s ability to provide security and process protection to other CPSes with varying levels of autonomy or distributed components.
2

Viability of Feature Detection on Sony Xperia Z3 using OpenCL

Danielsson, Max, Sievert, Thomas January 2015 (has links)
Context. Embedded platforms GPUs are reaching a level of perfor-mance comparable to desktop hardware. Therefore it becomes inter-esting to apply Computer Vision techniques to modern smartphones.The platform holds different challenges, as energy use and heat gen-eration can be an issue depending on load distribution on the device. Objectives. We evaluate the viability of a feature detector and de-scriptor on the Xperia Z3. Specifically we evaluate the the pair basedon real-time execution, heat generation and performance. Methods. We implement the feature detection and feature descrip-tor pair Harris-Hessian/FREAK for GPU execution using OpenCL,focusing on embedded platforms. We then study the heat generationof the application, its execution time and compare our method to twoother methods, FAST/BRISK and ORB, to evaluate the vision per-formance. Results. Execution time data for the Xperia Z3 and desktop GeForceGTX660 is presented. Run time temperature values for a run ofnearly an hour are presented with correlating CPU and GPU ac-tivity. Images containing comparison data for BRISK, ORB andHarris-Hessian/FREAK is shown with performance data and discus-sion around notable aspects. Conclusion. Execution times on Xperia Z3 is deemed insufficientfor real-time applications while desktop execution shows that there isfuture potential. Heat generation is not a problem for the implemen-tation. Implementation improvements are discussed to great lengthfor future work. Performance comparisons of Harris-Hessian/FREAKsuggest that the solution is very vulnerable to rotation, but superiorin scale variant images. Generally appears suitable for near duplicatecomparisons, delivering much greater number of keypoints. Finally,insight to OpenCL application development on Android is given
3

Měřič spotřeby elektrické energie / Electricity Consumption Measuring Appliance

Hájek, Zdeněk January 2011 (has links)
This thesis describes the designing and development of electricity consumption meter. First of all, a theoretical basis necessary for understanding a physical principle of measured subject is introduced. In the next part a suitable way of measuring in context of embedded devices is being looked for. Some of peripheral devices useful for project are described briefly. Then follows the detailed description of concept, that in the following part transforms to hardware design. Next part documents creation of the fi rmware. By the end of this thesis the project testing is described as well as the resume of gathered knowledge.
4

Towards the Implementation of an Energy Saving App State Migration Technique (ASMT)

Morris, Nathaniel Joseph January 2014 (has links)
No description available.
5

Modèles acoustiques à structure temporelle renforcée pour la vérification du locuteur embarquée / Reinforced temporal structure of acoustic models for speaker recognition

Larcher, Anthony 24 September 2009 (has links)
La vérification automatique du locuteur est une tâche de classification qui vise à confirmer ou infirmer l’identité d’un individu d’après une étude des caractéristiques spécifiques de sa voix. L’intégration de systèmes de vérification du locuteur sur des appareils embarqués impose de respecter deux types de contraintes, liées à cet environnement : – les contraintes matérielles, qui limitent fortement les ressources disponibles en termes de mémoire de stockage et de puissance de calcul disponibles ; – les contraintes ergonomiques, qui limitent la durée et le nombre des sessions d’entraînement ainsi que la durée des sessions de test. En reconnaissance du locuteur, la structure temporelle du signal de parole n’est pas exploitée par les approches état-de-l’art. Nous proposons d’utiliser cette information, à travers l’utilisation de mots de passe personnels, afin de compenser le manque de données d’apprentissage et de test. Une première étude nous a permis d’évaluer l’influence de la dépendance au texte sur l’approche état-de-l’art GMM/UBM (Gaussian Mixture Model/ Universal Background Model). Nous avons montré qu’une contrainte lexicale imposée à cette approche, généralement utilisée pour la reconnaissance du locuteur indépendante du texte, permet de réduire de près de 30% (en relatif) le taux d’erreurs obtenu dans le cas où les imposteurs ne connaissent pas le mot de passe des clients. Dans ce document, nous présentons une architecture acoustique spécifique qui permet d’exploiter à moindre coût la structure temporelle des mots de passe choisis par les clients. Cette architecture hiérarchique à trois niveaux permet une spécialisation progressive des modèles acoustiques. Un modèle générique représente l’ensemble de l’espace acoustique. Chaque locuteur est représenté par une mixture de Gaussiennes qui dérive du modèle du monde générique du premier niveau. Le troisième niveau de notre architecture est formé de modèles de Markov semi-continus (SCHMM), qui permettent de modéliser la structure temporelle des mots de passe tout en intégrant l’information spécifique au locuteur, modélisée par le modèle GMM du deuxième niveau. Chaque état du modèle SCHMM d’un mot de passe est estimé, relativement au modèle indépendant du texte de ce locuteur, par adaptation des paramètres de poids des distributions Gaussiennes de ce GMM. Cette prise en compte de la structure temporelle des mots de passe permet de réduire de 60% le taux d’égales erreurs obtenu lorsque les imposteurs prononcent un énoncé différent du mot de passe des clients. Pour renforcer la modélisation de la structure temporelle des mots de passe, nous proposons d’intégrer une information issue d’un processus externe au sein de notre architecture acoustique hiérarchique. Des points de synchronisation forts, extraits du signal de parole, sont utilisés pour contraindre l’apprentissage des modèles de mots de passe durant la phase d’enrôlement. Les points de synchronisation obtenus lors de la phase de test, selon le même procédé, permettent de contraindre le décodage Viterbi utilisé, afin de faire correspondre la structure de la séquence avec celle du modèle testé. Cette approche a été évaluée sur la base de données audio-vidéo MyIdea grâce à une information issue d’un alignement phonétique. Nous avons montré que l’ajout d’une contrainte de synchronisation au sein de notre approche acoustique permet de dégrader les scores imposteurs et ainsi de diminuer le taux d’égales erreurs de 20% (en relatif) dans le cas où les imposteurs ignorent le mot de passe des clients tout en assurant des performances équivalentes à celles des approches état-de-l’art dans le cas où les imposteurs connaissent les mots de passe. L’usage de la modalité vidéo nous apparaît difficilement conciliable avec la limitation des ressources imposée par le contexte embarqué. Nous avons proposé un traitement simple du flux vidéo, respectant ces contraintes, qui n’a cependant pas permis d’extraire une information pertinente. L’usage d’une modalité supplémentaire permettrait néanmoins d’utiliser les différentes informations structurelles pour déjouer d’éventuelles impostures par play-back. Ce travail ouvre ainsi de nombreuses perspectives, relatives à l’utilisation d’information structurelle dans le cadre de la vérification du locuteur et aux approches de reconnaissance du locuteur assistée par la modalité vidéo / SPEAKER verification aims to validate or invalidate identity of a person by using his/her speech characteristics. Integration of an automatic speaker verification engine on embedded devices has to respect two types of constraint, namely : – limited material resources such as memory and computational power ; – limited speech, both training and test sequences. Current state-of-the-art systems do not take advantage of the temporal structure of speech. We propose to use this information through a user-customised framework, in order to compensate for the short duration speech signals that are common in the given scenario. A preliminary study allows us to evaluate the influence of text-dependency on the state-of-the-art GMM/UBM (Gaussian Mixture Model / Universal Background Model) approach. By constraining this approach, usually dedicated to text-independent speaker recognition, we show that a lexical constraint allows a relative reduction of 30% in error rate when impostors do not know the client password. We introduce a specific acoustic architecture which takes advantage of the temporal structure of speech through a low cost user-customised password framework. This three stage hierarchical architecture allows a layered specialization of the acoustic models. The upper layer, which is a classical UBM, aims to model the general acoustic space. The middle layer contains the text-independent specific characteristics of each speaker. These text-independent speaker models are obtained by a classical GMM/UBM adaptation. The previous text-independent speaker model is used to obtain a left-right Semi-Continuous Hidden Markov Model (SCHMM) with the goal of harnessing the Temporal Structure Information (TSI) of the utterance chosen by the given speaker. This TSI is shown to reduce the error rate by 60% when impostors do not know the client password. In order to reinforce the temporal structure of speech, we propose a new approach for speaker verification. The speech modality is reinforced by additional temporal information. Synchronisation points extracted from an additional process are used to constrain the acoustic decoding. Such an additional modality could be used in order to add different structural information and to thwart impostor attacks such as playback. Thanks to the specific aspects of our system, this aided-decoding shows an acceptable level of complexity. In order to reinforce the relaxed synchronisation between states and frames due to the SCHMM structure of the TSI modelling, we propose to embed an external information during the audio decoding by adding further time-constraints. This information is here labelled external to reflect that it is aimed to come from an independent process. Experiments were performed on the BIOMET part of the MyIdea database by using an external information gathered from an automatic phonetical alignment. We show that adding a synchronisation constraint to our acoustic approach allows to reduce impostor scores and to decrease the error rate from 20% when impostor do not know the client password. In others conditions, when impostors know the passwords, the performance remains similar to the original baseline. The extraction of the synchronisation constraint from a video stream seems difficult to accommodate with embedded limited resources. We proposed a first exploration of the use of a video stream in order to constrain the acoustic process. This simple video processing did not allow us to extract any pertinent information
6

Autonomní generátor testovacích skriptů / Autonomous generator of test scripts

Horký, Stanislav January 2015 (has links)
The subject of this master thesis are state machines and their testing. To this purpose, an application is described, which is able to test these state machines autonomously. Application have two parts, first generator and editor of data is built and second part is testing procedure, which is able to test state machines in question and to give corresponding test report.
7

Trasování objektu v reálném čase / Visual Object Tracking in Realtime

Kratochvíla, Lukáš January 2019 (has links)
Sledování obecného objektu na zařízení s omezenými prostředky v reálném čase je obtížné. Mnoho algoritmů věnujících se této problematice již existuje. V této práci se s nimi seznámíme. Různé přístupy k této problematice jsou diskutovány včetně hlubokého učení. Představeny jsou reprezentace objektu, datasety i metriky pro vyhodnocování. Mnoho sledovacích algorimů je představeno, osm z nich je implementováno a vyhodnoceno na VOT datasetu.
8

Data koncentrátor pro chytré sítě / Data Concentrator for Smart Grids

Franek, Lešek January 2012 (has links)
The goal is to design data concentrator for Smart Grids. Data Concentrator provides the interface between the server systems of distribution companies and end devices, which are electricity meters, water meters, gas meters and other equipment. There are hardware and software design solutions and there is also discussed creating its own distribution of Linux.
9

Measuring the Technical and Process Benefits of Test Automation based on Machine Learning in an Embedded Device / Undersökning av teknik- och processorienterade fördelar med testautomation baserad på maskininlärning i ett inbyggt system

Olsson, Jakob January 2018 (has links)
Learning-based testing is a testing paradigm that combines model-based testing with machine learning algorithms to automate the modeling of the SUT, test case generation, test case execution and verdict construction. A tool that implements LBT been developed at the CSC school at KTH called LBTest. LBTest utilizes machine learning algorithms with off-the-shelf equivalence- and model-checkers, and the modeling of user requirements by propositional linear temporal logic. In this study, it is be investigated whether LBT may be suitable for testing a micro bus architecture within an embedded telecommunication device. Furthermore ideas to further automate the testing process by designing a data model to automate user requirement generation are explored. / Inlärningsbaserad testning är en testningsparadigm som kombinerar model-baserad testning med maskininlärningsalgoritmer för att automatisera systemmodellering, testfallsgenering, exekvering av tester och utfallsbedömning. Ett verktyg som är byggt på LBT är LBTest, utvecklat på CSC skolan på KTH. LBTest nyttjar maskininlärningsalgoritmer med färdiga ekvivalent- och model-checkers, och modellerar användarkrav med linjär temporal logik. I denna studie undersöks det om det är lämpat att använda LBT för att testa en mikrobus arkitektur inom inbyggda telekommunikationsenheter. Utöver det undersöks även hur testprocessen skulle kunna ytterligare automatiseras med hjälp av en data modell för att automatisera generering av användarkrav.
10

Σχεδιασμός και ανάπτυξη λογισμικού ΕΛ/ΛΑΚ (open source) για διαχείριση οποιασδήποτε ενσωματωμένης (embedded) και μη συσκευής / Extending and customizing OpenRSM for wireless embedded devices and LINUX

Κουμούτσος, Κωνσταντίνος 25 May 2011 (has links)
Οι ενσωματωμένες συσκευές αποτελούν μια κατηγόρια υπολογιστών ειδικού σκοπού με ραγδαία αύξηση τα τελευταία χρόνια. Σε αντίθεση με τους γνωστούς σε όλους υπολογιστές γενικού σκοπού που μπορούν να επιτελέσουν σχεδόν οποιαδήποτε λειτουργία, οι ενσωματωμένες συσκευές επιτελούν μόνο συγκεκριμένες λειτουργίες, οι οποίες είναι προκαθορισμένες κατά τον σχεδιασμό τους. Η διαχείριση τέτοιων και μη συσκευών αποτελεί ένα τεράστιο κεφάλαιο αφού η διαφορετικότητα των λειτουργιών τους, δημιουργεί ένα διαφορετικό τρόπο αντιμετώπισης τους κατά την πρακτική της διαχείρισης. Υπάρχει περιορισμός στα διαθέσιμα εργαλεία για την διαχείριση όλων των ενσωματωμένων συστημάτων με ένα εργαλείο, αλλά η ερεύνα μας επικεντρώνεται στη διαχείριση οικογενειών τέτοιων συσκευών με κριτήριο τη λειτουργία του ειδικού σκοπού που επιτελούν. Σκοπός λοιπόν της εργασίας είναι ο σχεδιασμός και η ανάπτυξη λογισμικού για την ομαδική διαχείριση οικογένειας ενσωματωμένων συσκευών και κοινών υπολογιστών γενικού σκοπού οπουδήποτε λειτουργικού συστήματος. Η συνεισφορά της υπάρχουσας εργασίας συνοψίζεται στις εξής συνιστώσες: 1. Οι ενσωματωμένες συσκευές στις οποίες επικεντρωθήκαμε αφορούν δικτυακές συσκευές (ασύρματες ή ενσύρματες) πολλών λειτουργιών (Access Points, Clients, Repeaters,Points to Points, WDS, Transparent Clients, Routers). 2. Το λογισμικό για υπολογιστές ειδικού σκοπού που δημιουργήθηκε μπορεί να εκτελεστεί τόσο σε λειτουργικά συστήματα MS Windows όσο και σε *ΝΙΧ. 3. Η ανάπτυξη του λογισμικού έγινε βάση του συστήματος ORSM, το οποίο είναι ένα εργαλείο ανοικτού κώδικα για την απομακρυσμένη διαχείριση συστημάτων και δικτύων. (Με αστερίσκο * τόσο στα περιεχόμενα όσο και στο κύριο μέρος της εργασίας δείχνουμε τις δυνατότητες του νέου λογισμικού σε σχέση με το σύστημα ORSM). Συνοπτικά οι δυνατότητες διαχείρισης αφορά τις παρακάτω λειτουργίες: • Ανακάλυψη περιουσιακών στοιχείων (Inventory Process). • Παρακολούθηση απόδοσης συστημάτων (Monitoring). • Εγκατάσταση και απεγκατάσταση λογισμικού (Software Deployment). • Απομακρυσμένο έλεγχο (Remote Desktop). • Εκτέλεση εντολών κελύφους (Remote Command). / An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions, often with real-time computing constraints. It is usually embedded as a part of a complete device including hardware and mechanical parts. In contrast, a general-purpose computer, such as a personal computer, can do many different tasks depending on programming. Embedded systems control many of the common devices in use today. Managing infrastructure with such devices (embedded and general purpose computers) is usually demanding and expensive but nevertheless essential for organizations. There is a limit in tools which achieve effective management to those infrastructure topologies. At present, open management solutions are few and immature however there are tools such as OpenRSM aiming to deliver lightweight, remote and customizable management, easily customizable to cover the needs of small organizations. OpenRSM implements a generic management framework that models generalized use cases that can be exploited by users to adapt the tool to their needs. However, given maturity of the tool, it is unclear how easy it would be for users to extend it in order to include management of new types of devices. As network environments grow to digital ecosystems, the management targets increase in number and diversity. Wireless active elements, handheld systems or embedded devices are becoming common and need to be brought under standard management practices in the same manner as routers or workstations. This paper describes how the OpenRSM management functionality can be extended in order to provide customizable management of embedded devices and more specifically of wireless access points (the symbol * shows the new extension of ORSM). In general the management capabilities which are embed to OPENRSM system and target to wireless active elements are: (Inventory process, monitoring, firmware upgrade, save/reload configuration settings, remote commands, and discovery process).

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