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  • 1.
    Adhikari, Ayush
    University West, Department of Health Sciences.
    Enhancing Vulnerability Management in Large Organisations through Machine Learning - Based Prioritisation: A Case Study2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The number of vulnerabilities is increasing daily, and organisations are flooded by vulnerabilities in their IT environment. The increasing number of vulnerabilities in organisations' IT environments presents a significant challenge, requiring effective identification and prioritisation of critical vulnerabilities. Different techniques exist to this date, such as CVSS scoring or Risk-based scoring from solution providers to perform prioritisation of vulnerabilities. However, large industries with extensive assets often face difficulty in managing and fixing a large pool of vulnerabilities, as traditional techniques tend to classify numerous vulnerabilities as high or critical. This study proposes a machine learning model based on the K-means++clustering technique that leverages vulnerability data and asset financial value assessments to find patterns within vulnerability and group the most critical vulnerabilities. Our study successfully determined a group of the most critical vulnerabilities from a sample dataset of vulnerabilities from one of the large organisations. By considering the financial value of assets, our solution demonstrates a more accurate prioritisation, enabling organisations to allocate resources effectively and address the most critical vulnerabilities first. This study enhances vulnerability management practices in large organisations and serves as a foundation for further research and development in vulnerability prioritisation using machine learning techniques

  • 2.
    Ahmetovic, Edvin
    University West, Department of Engineering Science.
    Estimation of Stator Temperature in an Electric Machinebased on Stator Resistance Computation2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Due to toughened CO2 emission standards the automotive industry is approaching a transition to zero-emission mobility. An accurate estimation of the stator temperature is an essential part of the motor controls and to protect the electric motor from overheating. An inaccurate estimation leads to bigger margins between estimated value and actual value to protect the electric motor which affects the performance. A literature study was performed which presented different methods that has been used in previous work to estimate parameters of an electric machine. The purpose of this master thesis is to find a suitable method and develop a temperature observer to estimate the stator winding temperature based on a resistance observer.In the development work three different methods were tested on a single-phase electric machine for the sake of simplicity. First method assuming steady state condition, second was the Forward Euler and third zero-order hold. The results showed that the zero-order hold method using a recursive least-square (RLS) optimization was performing the best in the higher frequencies but in the lower range the steady state RLS method was better which was also the method that was used on a three-phase electric motor model from a Nissan Leaf.The sensitivity analysis showed that the estimate of the stator resistance is sensitive to errors on the input variables and that the errors are highest in the mid-torque range and in the lower part of the speed range. The error on the input variables was arbitrarily chosen of +3 % and was added separately on the inductances and voltages of the d- and q-axis 𝐿𝑑, 𝐿𝑞, 𝑣𝑑, 𝑣𝑞, the rotor speed 𝜔 and the flux-linkage 𝜑. The variable that was affecting the resistance estimation the most was when a fault of 3% was introduced on the rotor speed 𝜔 which gave an error of more than -1200% on the estimated resistance. In nominal conditions, i.e. room temperature and constant stator temperature, the results showed an accurate resistance estimation of -0.4 – 1.4 % followed by an accurate temperature estimation

  • 3.
    Andell, William
    et al.
    University West, Department of Engineering Science.
    Eskel, Filip
    University West, Department of Engineering Science.
    DDoS Defense: Next-Generation Firewall versus Traditional Firewall2023Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Syftet med detta examensarbete var att utvärdera hur två olika brandväggar, en nästa generationens brandvägg och en traditionell brandvägg, hanterade en mindre distribuerad denial of service-attack. Enheterna kördes så nära dess förkonfiguration som möjligt. Testningengenomfördes i en kontrollerad labbmiljö på Högskolan Väst.

    Ett botnät bestående av 17 datorer användes och styrdes via en kommandocentral som använde IRC för att utföra attackerna. Enheterna testades med TCP- och UDP-baserade attacker under en tid av fyra minuter vardera. En dator var ansluten till det interna gränssnittet där vi kontrollerade minnet, CPU och latensen. En annan dator från botnätgränssnittet kontrollerade latensen från botnät.

    Resultaten visar att nästa generationens brandvägg (FortiGate40F) presterar bättre än den traditionell brandväggen (ASA 5506-X). Både Cisco ASA 5506-X och FortiGate 40F kör med 4 CPU-kärnor, där ASA 5506-X har 1250 MHz per kärna medan FortiGate 40F bara har 1200M MHz per kärna. ASA 5506-X har också 113,24% mer RAM än FortiGate. Trots att ASA 5506-X har fördelen när det gäller hårdvara, presterande FortiGate 40F bättre vid varje attack. Detta beror med stor sannolikhet på skillnaden i mjukvara hos de olika brandväggar

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  • 4.
    Buvarp, Daniel
    University West, Department of Engineering Science.
    Design and Evaluation of Heavy Electric Vehicle DC Charging Overcurrent Protection2022Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The vehicle industry must reduce emissions to lessen their environmental impact. Using electric motors for propulsion and batteries for energy storage decreases the pollution and greenhouse gases emitted by heavy commercial vehicles such as trucks and buses. As they often travel long distances, a large energy storage is needed, and it needs to be possible to recharge it quickly. The fast recharging requires high power chargers with high voltage and high current, and that in turn necessitates a suitable overcurrent protection system to avoid damageif a fault would occur.

    Possible technologies for this overcurrent protection system are investigated in this thesis, and the different solutions are evaluated based on important metrics. A solid state breaker is found to be a promising technology that limits the current quickly and reliably.

    The evaluation including computer simulations shows that the technology is feasible, but some aspects of the circuit design need to be executed carefully like the inductance, the sampling frequency of the current measurement, and the design of the snubber circuit.

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  • 5.
    Diels, Cyriel
    et al.
    ntelligent Mobility Design Centre, Royal College of Art, London, (GBR); Laboratory for Artificial Intelligence in Design, Hong Kong, (HKG).
    Stylidis, Kostas
    University West, School of Business, Economics and IT, Division of Media and Design. Department of Industrial and Materials Science, Chalmers University of Technology, 412 96, Gothenburg (SWE).
    Mausbach, Artur
    Intelligent Mobility Design Centre, Royal College of Art, London (GBR).
    Harrow, Dale
    Intelligent Mobility Design Centre, Royal College of Art, London, (GBR); Laboratory for Artificial Intelligence in Design, Hong Kong, (HKG).
    Shaping Autonomous Vehicles: Towards a Taxonomy of Design Features Instilling a Sense of Safety2022In: Communications in Computer and Information Science, ISSN 1865-0929, E-ISSN 1865-0937, Vol. 1583 CCIS, p. 172-180Article in journal (Refereed)
    Abstract [en]

    Autonomous vehicles (AVs) are Artificial Intelligence (AI)-enabled service robots. Whilst having the potential to enhance our transport systems and journey experiences, there are concerns that the public may be reluctant to adopt AVs, largely driven by doubts about their safety. In this study, we focussed on the role of the exterior vehicle design to instil a sense of safety on behalf of the passenger and bystander, i.e. pedestrians and cyclists. Senior automotive and transport designers were interviewed to identify key design features which revealed a common understanding of key features but also an apparent dichotomy or incompatibility in terms of design directions when considering passengers versus bystanders. Furthermore, designers’ understanding was largely based on their experience of conventional vehicles leading to uncertainty as to the validity in the context of future AVs. The results provide an initial set of design features that will be tested and evaluated with prospective AV users to explore the potential knowledge gap between designers’ intentions and customers’ expectation. This will provide design practitioners tangible, relatable anchors to direct activities towards critical design features whilst enabling design management to introduce more objectivity in their decision making.  

  • 6.
    Kimovski, Maria
    et al.
    University West, Department of Engineering Science.
    Falkner, Madeleine
    University West, Department of Engineering Science.
    Evaluation of steganography tools2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Digital steganography provides a way to communicate over unsecure channels by hiding data in digital media and exchanging it with the recipient, who in turn extracts it. Covert communication is used in many fields, as well as in the private sphere.

    In this thesis our goal was to provide a state-of-the-art review on steganography techniques in publicly available tools, identify the most common steganography techniques in publicly accessible tools and evaluate these based on the properties of imperceptibility and capacity.

    The techniques we found to be the most common were LSB, EOF-injection, DCT and an adaptive algorithm. We evaluated the most common tools that used these techniques, which were F5, Jsteg, OpenPuff, Steghide, SilentEye, and StegoStick. The spatial domain tools (SilentEye and StegoStick) outperformed the other tools when embedding in images, having a high capacity while retaining a relatively high imperceptibility. When embedding in audio,the transform and adaptive domain tools (F5, Jsteg, and OpenPuff) had a higher capacity while also upholding a high imperceptibility

  • 7.
    Patel, Deep
    et al.
    University West, Department of Engineering Science.
    Plakkel, Deepak
    University West, Department of Engineering Science.
    Torque control of Induction machine motor drive system based on closed loop FOC Method: Study & design of controller for Induction machine for HEV2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is based on the electrical drive system of a hybrid electric car that has been adapted for racing and uses an induction machine. It is one of the most often used electrical drives due to its robustness and simple construction. The induction motor model is based on the design of a race-purpose HEV created by the company Fengineering and their associates. The rated torque and power are only available at rated rpm in a conventional internal combustion engine vehicle. It also requires a certain amount of time to reach its maximum performance. In comparison to an electric motor, an internal combustion engine has excessive losses. The performance of the driveline can be improved by using an induction motor.

    The goal is to use a simulation environment to understand control theory (FOC) and create a control algorithm for an induction machine. It is, however, frequently controlled by a speed sensor or an open loop design, such as the well-known Volt/Hertz control. However, the supply currents of field-oriented regulated induction motors are controlled in real time, both in magnitude and phase, in response to the torque demand given by the vehicle torque controller. Different performance scenarios can be researched and studied utilizing the Vector control (Field oriented control) technique.

    First, a simple induction machine set up was constructed in the Simulink environment. This was done to investigate the primary factors that influence the induction machine's operation. The field-oriented control algorithm is made up of a closed control loop that constantly monitors the system's critical parameters in order to adjust the motor's torque and flux. The system will meet the requirements by constantly comparing the feedback quantities to the reference quantities. The software was used to model the control algorithm in the simulation environment. The algorithm was used to operate the induction machine using parameters that were similar to those that had already been modelled by Fengineering and their collaborators. The simulation results provide information on the induction machine's torque and speed characteristics. Field weakening is required to obtain speeds higher than the rated speed. The maximum torque per ampere principle is taken into account. The direct axis current (id) and quadrature axis current (𝑖𝑞) plays a very important role in the performance of the induction machine from the perspective of hybrid race car. The direct axis current (𝑖𝑑) and quadrature axis current (𝑖𝑞) can be balanced in such a way that the induction machine can deliver superior performance (greater torque and lower response time) especially in the early stages by enhancing the control algorithm.

  • 8.
    Patel, Pushpam Pankaj
    et al.
    University West, Department of Engineering Science.
    Chavan, Vitthal Rajaram
    University West, Department of Engineering Science.
    Sustainability in underground mining: Comparing haul trucks through operational costs and CO2 emission2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis explores the haul trucks comparison through CO2 emission and operational costs. The study focuses on the use of haul trucks in underground mining and discusses four distinct types of truck, with their merits and demerits. The aim of this research is to analyze and compare diesel, diesel with electric, electric with battery swapping, and electric with trolley charging haul trucks by maintaining consistency in truck data and mine production capacity. Hence this study provides valuable insights into the economically viable and environmentally conscious choice of haul truck for mining operations.

    The methodology section of this report involves analyzing an underground mining route for haul truck operation and calculating fuel consumption. The energy consumption of haul trucks is determined using reference data from the conference journal underground mining technology 2017, while operational costs and CO2 emissions are calculated using equations from the literature.

    The results are presented in graphs to help visualize and compare the operational costs and CO2 emissions of all haul trucks.The results from case application in this report show that the electric with trolley charging truck system is the opted choice. This adoption shows that it is cost-effective, with a daily operational cost advantage when compared to all other trucks. When it comes to CO2emission from energy consumption of trucks, electric-powered haul trucks have a lower emission when compared to other truck options

  • 9.
    Rohlsson, Joel
    et al.
    University West, Department of Engineering Science.
    Rosander, Dennis
    University West, Department of Engineering Science.
    A pre-study to enable a generator test facility to meet electrical safety regulations and for risk reduction2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    GKN Aerospace and its manufacturing facility in Trollhättan is currently lacking a generator test bench facility. A generator test rig is therefore to be developed and designed with regards to the possibility of future use of other machines. The generator will be powered by an electric machine. No load will be applied, however, 12000 revolutions per minute is required to be achieved. Hazardous voltage and current levels are expected as a result, and a pre-study focused on electrical safety and mitigation of risks is required. In the thesis work, textbooks, standards, scientific journals and reports have been used as references concerning applicable engineering standards and safety regulations. Applicable standards were used as a foundation of the work. The possible hazards of the test rig wereidentified and actions for risk mitigation implemented. Hazardous current levels, among others, such as high rotational speeds are present during the operation of the test rig. The test rig design resulted in a base plate with a set of rails with carriers and clamping mounts, where two machine mounts are attached, giving both the ability to adjust the distance and lock in place. Mounting of the machines is done using adapters that are machine-specific and can easily be replaced if desired. A machine guard made of polycarbonate and a checklist were produced, to assure safe operation of the test rig

  • 10.
    Stylidis, Kostas
    et al.
    University West, School of Business, Economics and IT, Division of Media and Design. Chalmers University of Technology, Department of Industrial and Materials Science, SE-412 96, Göteborg (SWE).
    Quattelbaum, Bastian
    Hochschule Niederrhein, Faculty Textile and Clothing Technology, D-41065, Mönchengladbach (DEU).
    Bergsjö, Dag
    Chalmers University of Technology, Department of Industrial and Materials Science, SE-412 96, Göteborg (SWE).
    Hellberg, Ebba
    Chalmers University of Technology, Department of Industrial and Materials Science, SE-412 96, Göteborg (SWE); China Euro Vehicle Technology AB, Customer Attributes Department, SE-417 55, Göteborg (SWE).
    Lundström, Oscar
    Chalmers University of Technology, Department of Industrial and Materials Science, SE-412 96, Göteborg (SWE); China Euro Vehicle Technology AB, Customer Attributes Department, SE-417 55, Göteborg (SWE).
    Siljefalk, Louise
    China Euro Vehicle Technology AB, Customer Attributes Department, SE-417 55, Göteborg (SWE).
    Heimersson, Emelie
    China Euro Vehicle Technology AB, Customer Attributes Department, SE-417 55, Göteborg (SWE).
    Söderberg, Rikard
    Chalmers University of Technology, Department of Industrial and Materials Science, SE-412 96, Göteborg (SWE).
    Perceived Quality Attributes Importance Ranking Methodology in the Automotive Industry: A Case Study on Geometry Appearance Attributes at CEVT2022In: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 107, p. 1559-1564Article in journal (Refereed)
    Abstract [en]

    Implementation of methods for perceived quality evaluation is an integral part of the automotive manufacturers’ strategic development plans. The correct definition of perceived quality requirements is one of the significant factors influencing customer’s purchase intention. This study seeks to understand how customers perceive and prioritize attributes that are associated with the geometrical and materials quality of a premium car market segment. We applied the Perceived Quality Attributes Importance Ranking (PQAIR) methodology to understand the importance of different perceived quality attributes form a customer perspective. Such an understanding can contribute to the effectiveness of the design processes in the early product development phases. This approach is tested on 144 respondents representing customer’s target group and performed in collaboration with China Euro Vehicle Technology (CEVT) technical experts. Our results verify the rationality and feasibility of the applied method and indicate the improvement of engineering practices regarding complex product development.  

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