While many of the currently used network intrusion detection systems (NIDS) employ signature-based approaches, there is an increasing research interest in the examination of anomaly-based detection methods, which seem to be more suited for recognizing zero-day attacks. Nevertheless, requirements for their practical deployment, as well as objective and reproducible evaluation methods, are hereby often neglected. The following thesis defines aspects that are crucial for a practical evaluation of anomaly-based NIDS, such as the focus on modern attack types, the restriction to one-class classification methods, the exclusion of known attacks from the training phase, a low false detection rate, and consideration of the runtime efficiency. Based on those principles, a framework dedicated to developing, testing and evaluating models for the detection of network anomalies is proposed. It is applied to two datasets featuring modern traffic, namely the UNSW-NB15 and the CIC-IDS-2017 datasets, in order to compare and evaluate commonly-used network intrusion detection methods. The implemented approaches include, among others, a highly configurable network flow generator, a payload analyser, a one-hot encoder, a one-class support vector machine, and an autoencoder. The results show a significant difference between the two chosen datasets: While for the UNSW-NB15 dataset several reasonably well performing model combinations for both the autoencoder and the one-class SVM can be found, most of them yield unsatisfying results when the CIC-IDS-2017 dataset is used. / Obwohl viele der derzeit genutzten Systeme zur Erkennung von Netzwerkangriffen (engl. NIDS) signaturbasierte Ansätze verwenden, gibt es ein wachsendes Forschungsinteresse an der Untersuchung von anomaliebasierten Erkennungsmethoden, welche zur Identifikation von Zero-Day-Angriffen geeigneter erscheinen. Gleichwohl werden hierbei Bedingungen für deren praktischen Einsatz oft vernachlässigt, ebenso wie objektive und reproduzierbare Evaluationsmethoden. Die folgende Arbeit definiert Aspekte, die für eine praxisorientierte Evaluation unabdingbar sind. Dazu zählen ein Schwerpunkt auf modernen Angriffstypen, die Beschränkung auf One-Class Classification Methoden, der Ausschluss von bereits bekannten Angriffen aus dem Trainingsdatensatz, niedrige Falscherkennungsraten sowie die Berücksichtigung der Laufzeiteffizienz. Basierend auf diesen Prinzipien wird ein Rahmenkonzept vorgeschlagen, das für das Entwickeln, Testen und Evaluieren von Modellen zur Erkennung von Netzwerkanomalien bestimmt ist. Dieses wird auf zwei Datensätze mit modernem Netzwerkverkehr, namentlich auf den UNSW-NB15 und den CIC-IDS- 2017 Datensatz, angewendet, um häufig genutzte NIDS-Methoden zu vergleichen und zu evaluieren. Die für diese Arbeit implementierten Ansätze beinhalten, neben anderen, einen weit konfigurierbaren Netzwerkflussgenerator, einen Nutzdatenanalysierer, einen One-Hot-Encoder, eine One-Class Support Vector Machine sowie einen Autoencoder. Die Resultate zeigen einen großen Unterschied zwischen den beiden ausgewählten Datensätzen: Während für den UNSW-NB15 Datensatz verschiedene angemessen gut funktionierende Modellkombinationen, sowohl für den Autoencoder als auch für die One-Class SVM, gefunden werden können, bringen diese für den CIC-IDS-2017 Datensatz meist unbefriedigende Ergebnisse.

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This diploma thesis deals with the design and implementation of an electronic module for acoustic detection. The module has the task of detecting a predetermined acoustic signals through them learned classification model. The module is used mainly for security purposes. To identify and classify the proposed model using machine learning techniques. Given the possibility of retraining for a different set of sounds, the module becomes a universal sound detector. With acoustic sound using the digital MEMS microphone, for which it is designed and implemented conversion filter. The resulting system is implemented into firmware microcontroller with real time operating system. The various functions of the system are realized with regard to the possible optimization (less powerful MCU or battery power). The module transmits the detection results of the master station via Ethernet network. In the case of multiple modules connected to the network to create a distributed system, which is designed for precise time synchronization using PTP protocol defined by the IEEE-1588 standard.

Per- and polyfluorinated substances (PFAS) are compounds that consist of a carbon chainbackbone that is partially or entirely fluorinated, with an addition of a functional group. SomePFAS are known as persistent organic pollutants (POPs) and have therefore been drawing a lot ofattention as well as increased concerns. PFAS have been detected in humans, wildlife and theenvironment and some have exhibited toxic effects such as hepatotoxicity, immunotoxicity,reproductive toxicity and endocrine disruption as well as being persistent and bioaccumulative.Serum, plasma and whole blood have been used as biomonitoring matrices in many studies toevaluate human exposure to PFAS. Restrictions have been applied to some PFAS, but thesecompounds are still ubiquitous. This study will investigate the performance (recovery, matrixeffect (ME) in terms of intra-/inter-day repeatability) of ion-pair extraction (IPE) and solid phaseextraction with weak anion exchange (SPE-WAX). The extraction methods were adapted fromliterature and 13 PFAS were selected for this work based on prior biomonitoring studies. Thetarget PFAS content was analyzed with liquid chromatography coupled with tandem massspectrometry (LC-MS/MS). The extraction methods were also compared for extractableorganofluorine (EOF) extraction in terms of blank levels as well as the amount extracted withdifferent methods; the EOF content was measured with combustion ion chromatography (CIC).The EOF levels were used to estimate the amount of unidentified organofluorine (UOF), to avoidunderestimating potential health hazards. Samples extracted using IPE had an average ionizationenhancement of 9%, while SPE-WAX showed an average ionization suppression of -1%. SPEWAXshowed higher average recoveries for procedural blanks (78%), horse serum (96%) andhuman serum (95%) in comparison to IPE (69%, 36%, 88%, respectively). The CIC analysis forEOF content was observed to be below MDL (<50 ng/mL F) with some contaminations observedin the procedural blanks.

Diploma thesis handles with set up of peripheral modules of the processor TC275 families’ AURIX developed by Infineon. Processor’s peripheral module QSPI implements communication SPI set up as master on a bus supported by another processor’s module DMA. Module DMA periodically service transmit and receive shift buffers of QSPI which are connected with slave analog to digital converter IC CIC751. Another peripheral module is MultiCAN. Programmed drivers used only basic header files with register definition of processor TC275, which are part of IDE TriCore Free Entry Tool Chain used for created drivers.

L'objectif de ce travail de thèse consistait à développer d'une technologie de mise en forme de poudres d'aciers faiblement alliés nitrurées afin d'introduire le nitrure ε-Fe2-3N dans la masse de la pièce mécanique.Pour atteindre cet objectif, deux voies ont été étudiées :- réaliser des pièces frittées à partir de poudre d'acier nitrurée ou nitrurée-enrobée (contenant une teneur importante en nitrure ε),- nitrurer et densifier une poudre d'acier pendant l'étape de frittage.La nitruration d'une poudre d'acier 4140 lors du frittage en CIC s'est avérée insuffisante vis-à-vis des teneurs en nitrure ε nécessaires pour l'application industrielle.L'étude de la stabilité, en CIC, de la poudre d'acier 4140 nitrurée a démontré la conservation des nitrures γ' et ε en grande proportion jusqu'à des températures de 650°C, quel que soit la nature du cycle de CIC appliqué. L'étude de la stabilité, à 600°C, de poudres d'acier nitrurées placées en capsules scellées a montré une légère dénitruration de ces poudres pendant le traitement.Des essais de densification de ces poudres d'acier nitrurées ont ensuite été réalisés par frittage SPS puis CIC. Afin de densifier les particules d'acier nitrurées, nous avons choisi d'utiliser un liant. Les essais de frittage SPS ont permis de mettre en évidence les paramètres expérimentaux les plus pertinents pour l'obtention d'un matériau dense et comportant le nitrure ε, et de proposer des préconisations sur les compositions acier-liant. Ces compositions ont été testées en CIC avec succès. Deux d'entre elles ont ainsi permis l'obtention de matériaux denses aux propriétés tribologiques et mécaniques satisfaisantes pour l'application industrielle. / The aim of this Ph.D thesis was to develop a technology to shape nitrided low-alloyed steels powders to introduce the ε-Fe2-3N nitride in the volume of the mechanical component.To achieve this goal, two approaches were considered:- the sintering of coated nitrided steel powder or nitrided steel powder (containing a high content of ε nitride),- the simultaneous densification and nitriding of low-alloy steel powder during the sintering step.Nitriding 4140 steel powder during hot isostatic pressing (HIP) does not allow producing sufficient ε-phase content for industrial application.The stability study of nitrided 4140 steel powder during HIP shows that a huge proportion of nitrides (γ' and ε) is conserved at 650°C, regardless of the HIP cycle. The stability study, at 600°C, of nitrided steel powders placed in sealed evacuated glass tubes, shows a slight denitriding of these powders during the process.Thus, densification of these nitrided steel powders was made by spark plasma sintering (SPS) and HIP. To densify the nitrided steel particles, we have used a copper-phosphorous binder. From SPS experiments, we have deduced the most relevant experimental parameters to obtain a dense material containing ε-phase, and we have proposed recommendations on the composition of nitrided steel-binder mixture. The identified compositions were successfully sintered by HIP. Two of them allow obtaining dense materials with interesting tribological and mechanical properties for industrial application.