University of Applied Sciences Emden Leer
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Entwicklung eines Secure IoT Gateways im Rahmen der NAMUR Open Architecture zur Verbesserung der IT-Sicherheit in industriellen Automatisierungssystemen
Full text linkDie fortschreitende Digitalisierung industrieller Automatisierungssysteme im Zuge von Industrie 4.0 führt zu einer immer stärkeren Vernetzung von Informationstechnologie (IT) und operativer Technologie (OT). Diese IT/OT-Konvergenz bringt zahlreiche Chancen, erhöht jedoch auch die Angriffsfläche für Cyberbedrohungen erheblich. Die NAMUR Open Architecture (NOA) bietet ein Referenzmodell, das eine sichere Integration moderner IT-Technologien in bestehende OT-Systeme ermöglicht, indem es Lebenszyklen von IT und OT trennt und kontrollierte Schnittstellen vorsieht. Zentrale Sicherheitskonzepte hierbei sind unidirektionale Kommunikation mittels Secure Gateways sowie das Verification-of-Request-Konzept (VoR), das sicherstellt, dass nur verifizierte Anfragen aus IT-Systemen in kritische OT-Prozesse weitergeleitet werden.
Im Rahmen dieser Masterarbeit wurde ein Secure IoT Gateway entwickelt, das die NOA-Prinzipien umsetzt. Für die IT/OT-Konvergenz nutzt die entwickelte Architektur containerbasierte Virtualisierung mittels Docker und setzt OPC UA als Kommunikationsprotokoll ein. Das Gateway ermöglicht eine sichere und modulare Kopplung von IT- und OT-Systemen, einschließlich Authentifizierung, Autorisierung und Verschlüsselung der Datenflüsse. Die Implementierung wurde anhand realer industrieller Anwendungsfälle in einer Testumgebung evaluiert und validiert. Die Ergebnisse zeigen, dass das entwickelte Gateway einen wirksamen und nachrüstbaren Beitrag zur Erhöhung der Cybersicherheit in industriellen Automatisierungsumgebungen leisten kann und eine praxistaugliche Referenzlösung für NOA-konforme Sicherheitsarchitekturen darstellt.The ongoing digitalization of industrial automation systems as part of Industry 4.0 is leading to an increasing convergence of information technology (IT) and operational technology (OT). This IT/OT convergence presents numerous opportunities, but also significantly expands the attack surface for cyber threats. The NAMUR Open Architecture (NOA) provides a reference model that enables the secure integration of modern IT technologies into existing OT systems by separating their life cycles and defining controlled interfaces. Key security concepts in this context include unidirectional communication via secure gateways and the Verification-of-Request (VoR) concept, which ensures that only verified requests from IT systems are forwarded to critical OT processes.
Within the scope of this master’s thesis, a Secure IoT Gateway was developed to implement the principles of NOA. For IT/OT convergence, the developed architecture leverages container-based virtualization with Docker and utilizes OPC UA as the communication protocol. The gateway enables secure and modular coupling of IT and OT systems, including authentication, authorization, and encryption of data flows. The implementation was evaluated and validated using real industrial use cases in a test environment. The results show that the developed gateway can provide an effective and retrofittable contribution to increasing cybersecurity in industrial automation environments and serves as a practical reference solution for NOA-compliant security architectures
Presenting an Ecco-Sustainable Approach to Decommission Offshore Wind Parks by Designing a New Ship, New Tools and Efficient and Reliable Procedure
Full text linkComprehensive research has been performed about involved fleets and offshore supply chain in installation and decommissioning of offshore wind parks. The finding revealed that lack of suitable cargo vessel in this industry compel the contractor to transport the wind farms’ components with installation vessel. This logistic configuration which is coveted in this industry is not so efficient in terms of cost and environmental footprint, in particular, for the wind farm with large number of wind turbines, with long distance from shore and with deep water. This fact was proofed in the third chapter where the time-cost-emission analysis of various case studies explained. High charter rate of the installation vessel contributes to increase in the overall cost of decommissioning or installation, if the transportation of components performs with installation vessel. Thus, the authors strived to design a multi-function and multi-purpose green vessel in order to bring down the cost of decommissioning of offshore wind parks. Plausible explanations regarding the specification of the Decom Tools vessel are provided including the dimension, engines, onboard equipment, propulsion system, solar system and so forth. Moreover, the stability and motion analysis have been performed in the chapter 7 and 8 which shows the seaworthiness of the vessel in different situations and operations under different conditions and sea states.
Significantly, after establishing the proper procedures and describing the method statements regarding all phases of decommissioning including, disassembly of wind turbine, removal of transition pieces, extraction of foundation and recovery of submarine power cables, time-cost-consumption-emission analysis for all above-mentioned phases of decommissioning undertake. Time-cost-consumption-emission analysis for disassembly of wind turbine has been explained in chapter 3. The mentioned analysis for the transition piece removal, pile extraction and cable recovery have been described in chapter 6.
Offshore wind farm by the name of Hornsea 1 was the main case study in this document. The mentioned analysis for this wind farm for the phase of disassembly of wind turbines which includes dismantling of rotor, nacelle and tower, removal of transition pieces and extraction of monopile have be conducted. However, for recovery of out-of-service submarine cables, Anholt wind farm is selected as case study since more information and sources about this wind farm is available.
The time-cost-consumption-emission analysis has been conducted with two different scenarios.
The first analysis has been carried out based on base scenario which is execution of decommissioning reverse to the installation. In this case, the same vessels and logistic configuration has been selected for the analysis. Thus, in the first run of the analysis, the resulting cost, fuel consumption and emission are calculated with developed program for the base scenario.
In the second run of the analysis, the analysis has been performed according to the proposed procedure and utilization of the Decom Tools vessel. This time, the logistic configuration and involved fleet of the decommissioning have been changed in order to reduce the offshore operation duration, project cost and mitigate the consumption and consequently the emission. The Decom Tools vessel is a multi-function and multi-purpose green vessel which can carry considerable number of wind turbine components. This capability led to reduction of the sailing time which lessen the fuel consumption and mitigate the CO2 emission. Furthermore, the designed blade seafastening (blade rack) and designed cutting tools, enable to cut the blades into the small pieces without spread of small piece of blades material into the sea and environment which pave the way for easier and cheaper onshore materials handling, transportation and recycling.
Equally important, the designed hydraulic gripper at the stern of the vessel allows removal of transition pieces without deployment of construction vessel. Implementation of this tool onboard Decom Tools vessel eliminate utilization of construction vessel which has high charter rate, considerable fuel consumption and emission. The analysis of transition piece removal operation indicates that this innovative tool diminishes the cost and emission enormously.
Not only the hydraulic gripper tool can be used during transition piece removal but also it can be utilized for pile extraction. Pile extraction can be executed with hydraulic grippers and the potent buoyancy of the vessel. In general, one of the cost drivers of the installation or decommissioning operations is construction vessel which can be either jack up vessel or floating heavy lift vessel. The proposed method of pile extraction with the hydraulic gripper and vessel’s buoyancy eliminates the use of heavy lift vessel, the diving system and subsea operations such as subsea cutting tools.
The results of time-cost-consumption-emission analysis proofed that substantial saving in terms of time, cost and fuel consumption can be achieved if such tool and procedure can be executed.
The other innovation which was presented in this document is the design of cable hydraulic gripper as well as establishment of the procedure for the recovery of out-of-service submarine cables. It is demonstrated that recovery of out-of-service cables can be conducted with some widely available tools and without using cable laying vessel. The proposed procedure is discussed with specialist of this industry and they confirmed the feasibility of the procedure
Development of an Interpretable Maritime Accident Prediction System Using Machine Learning Techniques
Full text linkEvery year, maritime accidents cause significant losses to human life, vessels, and the environment, impacting over 80% of global trade by volume. These incidents not only disrupt global trade but also pose long-term ecological and economic risks. To address this challenge, this thesis proposes a Machine Learning–based Maritime accident prediction system that enables proactive risk assessment and prevention. Unlike conventional studies, which primarily conduct ex-post statistical analyses of accidents, this work adopts a holistic, proactive, and interpretable approach, integrating vessel, environmental, operational, and human factors into a unified predictive framework.
The research begins with an extensive literature review and expert consultations to identify relevant risk factors. Two datasets — raw maritime incident logs and a refined, structured dataset were collected from publicly available sources, integrated, cleaned, and pre-processed for analysis. Exploratory data analysis (EDA) and feature engineering were conducted to capture complex patterns and dependencies, while variable selection and hot-spot detection techniques were applied to prioritize key predictors.
A range of Machine Learning models were evaluated and compared. The results demonstrate that the proposed system achieves competitive prediction accuracy, with models such as logistic regression and KNN showing promising performance for accident risk classification. To ensure trust and adoption, Interpretable Machine Learning (IML) methods (LIME, SHAP) were incorporated, allowing the system to provide transparent explanations of risk predictions.
The system was implemented using Python, Flask, and SQLite, with a web-based interface for user interaction. Evaluation results confirm its effectiveness in predicting Maritime accidents and highlight its potential for real-world applications, including risk management by maritime authorities, safer voyage planning, and integration into future autonomous navigation systems.
This thesis contributes to the growing body of maritime safety research by bridging the gap between high-accuracy predictive modeling and the practical need for explainable and user-oriented decision-support systems
Validation of a qualitative detection method for Listeria monocytogenes and Listeria spp. in food, feed and environmental samples using SureTect™ PCR kit
Full text linkListeria has been a predominant and significant pathogenic threat toward livestock animals, causing various diseases that endanger the survivability of the animals themselves, as well as their future rearing and their impactful benefits for the nourishment of humanity. The ability to detect the presence of Listeria has also been studied and improved continuously by scientists and method developers. One of the most prevalent method of detecting them nowadays is by using Polymerase Chain Reaction (PCR) technology by amplifying the DNA sequence of target bacteria and associate the molecule with fluorescence protein probes, which could then be detected by the fluorescent signal emitted. SureTect™ Listeria monocytogenes & Listeria spp. PCR assays by Thermo Fischer Scientific (2020) offer the application of this system, improved by the technology of “real-time PCR”, where the monitoring of the fluorescence could be observed while the amplification processes occur. The main objective of this thesis is to perform a validation of SureTect™ PCR method by comparing the method with the already established ISO 11290 method as a reference for the detection of Listeria in food, livestock feed and environmental samples to establish the use of this method in laboratory. The PCR method was tested to determine its detection limit, specificity, sensitivity, robustness and recovery while also comparing these parameters with the referenced ISO method and the validation data of external validation experiments by various laboratories.Listerien stellen seit langem eine vorherrschende und bedeutende pathogene Bedrohung für Nutztiere dar, da sie verschiedene Krankheiten verursachen, die nicht nur das Überleben der Tiere selbst gefährden, sondern auch ihre zukünftige Aufzucht sowie die wesentlichen Vorteile, die sie für die Ernährung der Menschheit bieten. Die Fähigkeit, das Vorhandensein von Listerien zu erkennen, wurde von Wissenschaftlern und Methodenentwicklern kontinuierlich untersucht und verbessert. Eine der heutzutage am weitesten verbreiteten Methoden zu ihrer Detektion ist die Verwendung der Polymerase-Kettenreaktion (PCR), bei der die DNA-Sequenz der Zielbakterien vervielfältigt und mit fluoreszierenden Proteinsonden verknüpft wird, die anschließend über das ausgesandte Fluoreszenzsignal nachgewiesen werden können. Die SureTect™ Listeria monocytogenes & Listeria spp. PCR-Assays von Thermo Fisher Scientific (2020) ermöglichen die Anwendung dieses Systems, das durch die Technologie der „Real-Time-PCR“ verbessert wurde, bei der die Fluoreszenz während der Amplifikationsprozesse beobachtet werden kann. Das Hauptziel dieser Arbeit ist die Validierung der SureTect™ PCR-Methode durch den Vergleich mit der bereits etablierten ISO-11290-Methode als Referenz für den Nachweis von Listerien in Lebensmitteln, Futtermitteln für Nutztiere und Umweltproben, um den Einsatz dieser Methode im Labor zu etablieren. Die PCR-Methode wurde getestet, um ihre Nachweisgrenze, Spezifität, Sensitivität, Robustheit, Wiederfindung und Zwischenpräzision zu bestimmen und gleichzeitig diese Parameter sowohl mit der Referenzmethode nach ISO als auch mit den Validierungsdaten externer Validierungsexperimente verschiedener Laboratorien zu vergleichen
Bispezifische Antikörper-vermittelte Zytotoxizität von γδ T-Lymphozyten gegenüber Cisplatin-resistenten und sensitiven Tumorzellen unter Einbezug der Fluoreszenzmikroskopie
Full text linkHumane γδ T-Lymphozyten besitzen die Fähigkeit eine Vielzahl von Tumoren durch Major Histocompatibility Complex (MHC)-unabhängige Erkennung spezifischer Antigene zu lysieren. In der Vergangenheit wurden monoklonale Antikörper genutzt, um die zytotoxischen Fähigkeiten von Immunzellen zu erhöhen. Durch den wissenschaftlichen Fortschritt werden heutzutage vermehrt bispezifische Antikörper (bsAk) wie der [(HER2)2×Vγ9] verwendet. [(HER2)2×Vγ9] kann bedingt durch seine Struktur sowohl an die Tumorzellen als auch an Vγ9Vδ2-exprimie-rende γδ T-Zellen binden und die Vγ9Vδ2 T-Zell-vermittelte Zytotoxizität gegenüber Humanem epidermalem Wachstumsfaktor Rezeptor (HER) 2-exprimierenden Tumoren deutlich erhöhen. Da Vγ9Vδ2 T-Zellen im Blut nur einen geringen Anteil ausmachen, können diese direkt über phosphorylierte Zwischenprodukte des Rhomer-Stoffwechselwegs wie z.B. durch Isopentenylpyrophosphat oder indirekt über Aminobisphosphonate selektiv expandiert werden. Die Immuntherapie mit bsAk bietet zukünftig eine sehr gute Alternative zu den unspezifischen Chemotherapien, wogegen manche Tumorzellen resistent sind. In dieser Arbeit konnte durch die Real-Time Cell Analysis (RTCA) gezeigt werden, dass die Cisplatin-sensitive Ovarialkarzinomzelllinie Igrov-1 durch Vγ9Vδ2 T-Zellen ebenso lysiert werden kann wie die Cisplatin-resistente Ovarialkarzinomzelllinie OVCAR-3. Der bsAk [(HER2)2×Vγ9] konnte bei beiden Zelllinien die Zytotoxizität deutlich erhöhen, jedoch mit Unterschieden zwischen beiden Zelllinien. OVCAR-3 Zellen wurden beim Einsatz des bsAk [(HER2)2×Vγ9] besser durch Vγ9Vδ2 T-Zellen lysiert als Igrov-1 Zellen unter gleichen Bedingungen. Die RTCA liefert eine wertvolle und genaue Echtzeitbetrachtung der Zytotoxizität. Die Fluoreszenzmikroskopie ist eine Methode, die detaillierte und hochauflösende Bilder liefern kann und somit die RTCA visuell unterstützt. Bei der Etablierung der Methode zur Anwendung der Fluoreszenzmikroskopie zum Nachweis der Zytotoxizität wurden verschiedene fluoreszierende Substanzen sowohl bei unterschiedlichen Tumorzelllinien als auch bei Vγ9Vδ2 T-Zellen getestet. Die Auswertung der Daten durch das Celleste Imaging System ermöglichte es, Zelltod bzw. Zelllyse von Tumorzellen ähnlich
der RTCA zu verfolgen sowie die Wirkung des bsAk [(HER2)2×Vγ9] auf die Zytotoxizität zu verdeutlichen. Die erhaltenen Ergebnisse zeigen die Vorteile der Verwendung eines bsAk in der Immuntherapie und eine neue Möglichkeit der visuellen Nachverfolgung der Vγ9Vδ2 T-Zell-Zytotoxizität gegenüber Tumorzellen
Investigating the working mechanism of Argyrin D, an antibiotic and potential new drug against Toxoplasma gondii
Full text linkToxoplasma gondii is an apicomplexan parasite, that has infected a third of the global population. This infection causes Toxoplasmosis, with usually flu-like symptoms, before differentiating into dormant cysts in muscle and brain tissues. However, in cases of immunocompromised, pregnant or new-born patients it can cause sever symptoms, including a long-term impairment of the patients’ sight. Because current treatments can only supress the infection, not clear parasites from patients, new treatment options will be necessary to prevent severe cases of
Toxoplasmosis.
This study examines argyrin D, a promising drug candidate for toxoplasmosis treatment. It was found, that argyrin D does indeed inhibit T. gondii growth in in vitro culture. Argyrin D’s effect on T. gondii’s cell cycle, and mitochondrial shape were investigated using immunofluorescence assays. Further, in the process of this study, a novel experiment design using live imaging microscopy was devised. This allowed us to further investigate growth of T. gondii culteres, plaque growth and the cidal or static effects of differend compounds on Argyrin D
Optimization and standardization of photometric methyl viologen-based enzyme activity assay for reductive dehalogenases from Dehalococcoides mccartyi strain CBDB1
Full text linkReductive dehalogenases (RDases) are key enzymes for the dehalogenation reaction that drives the microbial detoxification of persistent organohalide pollutants in bioremediation using organohalide-respiring bacteria. Despite their proven dehalogenation capability on a broad range of toxic pollutants, the characterization of their reactivity towards a specific substrate have been limited by the lack of a standardized, high-throughput RDase activity assay. This is addressed in this study by optimizing and standardizing the photometric, methyl-viologen based RDase activity assays using Dehalococcoides mccartyi strain CBDB1 as a model organism, as a small step towards establishing a high-throughput RDases screening method. The key parameters of the photometric assay were systematically tested and has achieved stable baseline absorbance for negative controls, prevented formation of condensation on the lid and resolved background oxidation issue. The optimized RDase activity assay using whole cells and crude extracts of strain CBDB1 with different RDase profiles was challenged with different artificial electron acceptors. RDases revealed general substrate preference towards brominated over chlorinated organohalides and towards doubly-flanked halogen substituents. High expression of CbdbA1092 in culture cultivated solely on 3,5-L-dibromotyrosine supported previous indication of its possible specificity towards brominated phenolic substrates. Subsequent gas chromatographic analysis of the assay samples adequately proved the measurement reliability and results accuracy of the photometric assay. As has been shown for some samples, comparable results between theoretically formed product concentration in the photometric assay and the actual concentration, determined by GC were observed, even though a more consistent results would be required. Overall, this work has provided
preliminary data on the way to establish a universal methyl viologen-based photometric RDases activity assay and has managed to clarify the method as well as solve some technical problems. Further studies should be conducted to establish it as a high-throughput method for the screening of RDases
Evaluation of B16-F1 melanocytes as a potential screening model for melanogenesis modulating compounds
Full text linkHuman skin is perpetually exposed to a multitude of environmental stimuli, yet it maintains an effective barrier against harmful influences through specialized mechanisms and cells. In light of this, it is essential for many people to take care of their skin. Furthermore, cosmetics are used to realize various hedonic needs and aesthetic ideals. One branch of cosmetic research focuses on high-throughput screenings, which are used to identify new substances for product development. Utilizing molecular as well as cell biological methods, the murine melanocyte cell line B16-F1 was characterized, determining its suitability to be ultimately used within a ‘Melanin-Assay’. Therefore, comparative tests were conducted, which assessed B16-F1’s melanogenic stimulation as well as its inhibition in relation to the established melanocyte cell line B16V. It emerged that the melanogenesis of B16-F1 melanocytes was substantially higher. In addition, screenings of different melanogenesis inhibiting compounds revealed that B16-F1 appeared to be less affine than B16V. Especially low concentrations of melanogenesis inhibitors depicted small to no effect on B16-F1 melanocytes. Subsequent assays of expression analysis via immunofluorescence imaging and In-Cell Western were conducted to eluci-date critical protein expression throughout melanogenesis. Although the In-Cell Western did not provide robust data sets, certain aspects of the data provided room for interpretation of melanogenic processes. Whether a transition of cell lines from B16V to B16-F1 is justified would have to be confirmed by further experiments
Pre- and Post-Synthesis Design Evaluation for Side-Channel-Robustness as part of a Design Flow using an AES Implementation as a Sample Design
Full text linkThis Bachelor thesis examines how the security of a hardware Advanced Encryption Standard (AES) implementation can be influenced at both pre- and post-synthesis levels. At pre-synthesis level, side-channel vulnerabilities are analysed using Simple Power Analysis (SPA). Countermeasures are implemented into the design, which significantly improve SPA results in pre-synthesis simulation, but prove less effective in post-synthesis layout simulation.
This study then explores how different post-synthesis layouts and data variations affect Differential Power Analysis (DPA) results. Layouts synthesised with the same Process Design Kit (PDK) are compared based on their DPA results to evaluate the influence of layout variations on DPA results. Then, the same layout is tested with identical or different data inputs, to analyse the impact of data variations on DPA results. Overall, variations in DPA results are minimal, suggesting that layout or data variations have little impact on side-channel robustness.
Lastly, the influence of PDK choice on DPA results is examined by synthesising the AES design with different PDKs. Despite variations in layout size and toggle behaviour, no conclusive relationship between PDK choice and DPA resistance is identified. These findings indicate that post-synthesis optimisations have only a small impact on side-channel security, showing the need for pre-synthesis countermeasure implementation
Demokratische Diskurse stärken: Die deliberative Demokratie als Antwort auf die Normalisierung des Rechtspopulismus
Full text linkDie vorliegende Arbeit beschäftigt sich mit der Frage, wie demokratische Diskurse in Anbetracht der Normalisierung des Rechtspopulismus gestärkt werden können. Dazu wird die deliberative Demokratie als demokratie- und diskurstheoretisches Gegenmodell zu rechtspopulistischen Dynamiken durchleuchtet. Ausgangspunkt bildet eine theoretische Auseinandersetzung mit dem Phänomen des Rechtspopulismus, welchedie zentralen Merkmale und Wirkweisen herausarbeitet. Dabei zeigt sich, dass der ideologische Kern grundlegend auf Abgrenzung beruht und in seinen angenommenen
Wirkungen demokratiegefährdend sein kann. Darauf aufbauend wird die deliberative Demokratietheorie, in enger Anlehnung an Jürgen Habermas, als normativer Gegenentwurf herangezogen. Ihre zugrundeliegenden Prinzipien beruhen vor allem auf rationalen Aushandlungen, Inklusion aller sowie Gleichberechtigung und bieten einen Bezugsrahmen, um Rechtspopulismus in demokratischen Diskursen kritisch zu analysieren. Gleichzeitig werden dabei aber auch die Grenzen dieser Theorie, z.B. aus radikaldemokratischer Perspektive, diskutiert. Die Gegenüberstellung des Rechtspopulismus mit der deliberativen Demokratie verweist auf ein Spannungsverhältnis zwischen beiden: Während Rechtspopulismus z.B. auf Polarisierung und Abgrenzung setzt, zielt die deliberative Demokratie auf Verständigung und Inklusion ab. In diesem Zusammenhang verdeutlicht die Normalisierung des Rechtspopulismus dabei die Gefahr, dass demokratiegefährdende Positionen zunehmend in die gesellschaftliche Mitte vordringen, wodurch nicht nur die soziale Kohäsion geschwächt werden kann, sondern langfristig auch die politische Ordnung destabilisiert werden könnte. Als mögliche Gegenstrategien lassen sich aus der deliberativen Demokratie zwei zentrale Ansätze ableiten: Einerseits bieten deliberative Beteiligungsverfahren, wie etwas Bürgerräte, die Chance, moderierte Räume des Austauschs zwischen unterschiedlichen gesellschaftlichen Gruppen zu schaffen. Auf diese Weise können demokratische Diskurse durch dialogorientierte Auseinandersetzungen gefördert werden. Andererseits wird die Relevanz struktureller Rahmenbedingungen betont, insbesondere einer resilienten deliberativen Öffentlichkeit, die auf einer lebendigen Zivilgesellschaft gründet und dazu beiträgt, demokratische Diskurse zu festigen. Damit verweist die Arbeit auf weitere Forschungsperspektiven, insbesondere zur empirischen Untersuchung deliberativer Verfahren mit Blick auf Polarisierung und soziale Kohäsion im Kontext von Rechtspopulismus