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Implementation of the Neoclassical Tearing Mode model in the European Transport Simulator integrated modelling workflow
No full textOptimizing Water Tank Levels Using Genetic Algorithms
No full textThis thesis presents a practical optimization framework for energy-efficient pump scheduling in water
distribution systems. It combines the practicality of rule-based control with the global-search power
of genetic algorithms. A novel setpoint curve encoding scheme is introduced, in which daily tank level targets are parameterized by a small set of meaningful coefficients (baseline, peak/dip timing
and amplitude, and curvature descriptors). These key parameters are then optimized using a custom
genetic algorithm, coupled with EPANET-driven hydraulic simulations. Constraint handling is
managed by penalty functions for demand security, hydraulic feasibility, reservoir volume balance
and pump maintenance. The framework is first demonstrated on the simplified NET-1 hydraulic
network, providing insight on how to algorithm operate. The optimization algorithm is subsequently
applied to a calibrated high-pressure zone (HPZ-G) of the Gothenburg water network, using historical
operational data for model validation. Results indicate that the optimized setpoint curves can reduce
energy cost, whilst still hydraulic and operational constraints. However, certain data gaps are
identified which would need to be addressed to improve the model’s validity
The mathematics of the ideal villa; the architectural potential of Swedish light frame construction
No full textThis work has examined the light-frame house, focusing on
how a house can be built cost-effectively without compromising
architectural quality. The relevance of exploring how
qualitative houses can be built while remaining cost-effective
comes from the notion that the typical prefabricated Swedish
house is seldom beautiful nor functional, and that a home
is often the largest financial investment a person makes in
their life.
The light-frame construction method has long been the most
common way of building small houses. One of the major advantages
of today’s light-frame construction is its flexibility;
the building system can be adapted to a variety of designs,
and its common use has developed the existing industry furthering
its availability and affordability.
Light-frame construction is derived from North America and
has evolved into a parallel Swedish tradition. The market in
North America, and thus the research on the topic is larger.
In this work, ideas have been taken from there and adapted
to Swedish conditions: the house can be designed based on
the properties of the materials and a conscious thought about
how it will be built.
The method to arrive at this has mainly been to iteratively
sketch various solutions to find architectural efficiency. Additionally,
mathematical analysis of the materials’ properties
has been used to identify principles that have then been applied.
Building references that achieve great architecture with
modest means have been analyzed and used in the project.
The outcome of the project is a flexible, detached single-family
house of 124 square meters on a medium-sized plot on
the outskirts of Gothenburg. The goal of the work has been
achieved by answering the research questions through designing
a house that harmonizes with its surroundings and
is based on rational principles derived from the materials
and rational construction methods available on the market.
The aim of the project has been to create a house that embodies
the Vitruvian principles of firmness, utility, and beauty,
and mine: affordabilit
Living and learning; a transformative journey adaptive reuse of the humanities library in Gothenburg University into student community and housing
No full textThe transformation of an existing structure through adaptive reuse offers a sustainable solution to
the growing demand for student housing, while limiting new construction and preserving historical
and valuable buildings. This thesis explores the adaptive reuse of the building UB80 in the Humanities
Library at Gothenburg University into student community space and housing. The goal is to
maximize the building’s use and potential by integrating communal spaces with residential spaces
that introduce the concept of social sustainability.
The project begins by examining the principles of adaptive reuse and circular economy, exploring
case studies of similar transformations and existing examples in the field of community spaces and
student housing. It considers the concept of a library as a space for community interaction and
knowledge exchange that reflects the story of humanity. The thesis examines the connection between
human needs for social interaction, living and learning, focusing on how these three essential
elements can be integrated to create a functional and sustainable environment.
User engagement and architectural tools were the main components of the design process, through
interviews, surveys, and study visits, along with SDG impact assessment tool. These methods
ensured that the project aligns with the needs of the community and meets the concept of sustainability.
This thesis proposes a model for adaptive reuse of a library that balances the preservation of architectural
buildings with the creation of functional, sustainable spaces that meet the needs of modern
student life and provide balance between living and learnin
Modeling and Control of Aeration in a Wastewater Treatment Plant
No full textIn this thesis, several modified control strategies for aeration control in a wastewater treatment plant are implemented. Their performance with focus on energy consumption and airflow pattern is evaluated and compared to the existing control system. In the wastewater treatment process (WWTP), the biological step is where oxygen is needed to regulate the ammonium levels in the effluent water, which can therefore be controlled with the airflow. A model of a wastewater treatment plant (WWTP) was built in Simulink to simulate the plant and evaluate the different control strategies. Time periods for real-world data were selected and used, both for evaluation of the model accuracy and the control system performance. The final conclusions made are that there is room for improvement of the control system with for example feedforward of the inflow rate. However, improvements are limited to the daily variations and cannot help suppress the very high spikes in ammonia concentration seen a few times a year. The likely cause being that these are present due to capacity constraints being reached in the system. Energy consumption was also not substantially lowered by the modified control strategies and therefore, they are not recommended in their current form. Attempts were also made to implement an LQG controller. However, an LQG controller is based on a linear model of the system, and the WWTP is highly nonlinear with global stability concerns. Thus, an LQG controller was not feasible for this system
2D imidazole- and thiazole- based COFs. Syntheses parameters using linker exchange.
No full textConstructing new materials for proton conduction above 100 °C is vital for the development of robust proton-exchange membrane fuel cells. Utilizing the remarkable proton conducting properties of polybenzimidazole and the tunable properties of covalent organic frameworks (COF), it is possible to create chemically stable structures that can be used as scaffolds for dopants. This thesis aimed to shed light on both how to increase the crystallinity of imidazole and thiazole COFs, and how to construct a reversible, highly crystalline imine-based COF that can be used as a prenetwork (PN) for the irreversible COF synthesis. The PN underwent linker exchange in order to create imidazole COFs with crystallinity equal to that of the PN. Different configurations of temperature, modulator, oxidant, excess reagent, and time were tested to examine their impact on the PN and imidazole COFs. The results indicate the successful creation of crystalline imidazole COFs when synthesized with modulators, pressured air and excess reagent during linker exchange. Modulators were shown to have low impact on the crystallinity of the PN and a high impact on the crystallinity of the imidazole COF, making their use vital during imidazole COF synthesis
Optimizing Cement Use in Sustainable Sandcrete Blocks: Standardizing Low-Strength Mortar Testing and Evaluating BYF Cement Feasibility
No full textThe urgent demand for sustainable and cost-effective construction materials has prompted the exploration of alternative binders to conventional Portland cement. However, a significant methodological gap persists, where alternative binders intended for low-strength mortars are often evaluated using the EN 196-1 standard, which is designed for high-strength cementitious systems and thus not representative of low-strength performance contexts such as sandcrete block production.
This study investigates the technical feasibility of Belite-Ye'elimite-Ferrite (BYF) cement as an alternative binder for low-strength applications, with a particular focus on sandcrete block production for sustainable construction in Sub-Saharan Africa. It introduces a modified testing methodology that adapts standard procedures to the low-strength context. Key modifications include the use of mix design representative of low-strength mortar anchored on bulk density control, and a reduction in specimen replicates from six to three to reflect the operational characteristics of tailored adjustments to casting and compaction protocols.
Experimental results demonstrate that BYF cement specimen at 7% cement content and 14% water content achieves a comparable 1-, 7- and 28-day compressive strength to Portland cement specimen at 7% cement and 11% water (4.5MPa, 5.2 MPa, and 6.7 MPa vs 1.9 MPa, 4.1 MPa, and 6.1MPa respectively), with improved repeatability and reduced variability in test outcomes. Further analysis shows that BYF at 5% cement content and 11% water content achieves a comparable result (3.73 MPa, 6.3 MPa, and 6.7 MPa respectively). XRD analysis confirms early and sustained strength development, supporting its viability as a low-carbon alternative binder. Regression analysis further established a moderate correlation (R² = 0.4046) between bulk density and compressive strength, with compaction shown to be a critical variable.
The findings support the technical feasibility of BYF cement as a low-carbon alternative for low-cost housing applications and proposes a reproducible testing methodology for evaluating low-strength binders. However, further research is needed on durability performance, field application, and economic feasibility to support broader adoption.
Key words: BYF cement, Portland Cement, Low-strength Application, Sustainable Sandcrete Blocks, EN 196-1 Modified Testing Method, Compressive Strength, Bulk Density, Sub-Saharan Africa, Cement Hydration
Map Inaccuracies Of Digital Twins For Localization
No full textDigital twins are increasingly vital in wireless communication for simulating, analyzing,
and optimizing real-world environments, particularly for sensing and localization
applications. The fidelity of these digital representations is dependent on the quality
of the underlying maps, which, in practical industrial settings, are often procured
at significant cost and may exhibit a range of inaccuracies due to survey limitations,
temporal changes, and misalignments of the data. This thesis investigates the
impact of map inaccuracies, specifically building rotations and translations, on localization
accuracy and received signal strength Indicator(RSSI) distributions within
a digital twin framework.
A comprehensive methodology was developed that combined ray tracing (using
Sionna), mesh manipulation (using PyVista), and Monte Carlo simulation. The
process included generating randomized maps according to realistic specifications,
simulating electromagnetic propagation on both baseline and perturbed maps, and
systematically extracting key channel and localization metrics. Several maximum
likelihood-based (ML) positioning algorithms, including Vanilla MLE, Weighted
MLE, Gain-Weighted Nonlinear Least Squares and Newton-Raphson ML, were implemented
and benchmarked using synthetic multipath data generated via digital
twin simulations.
Experimental results demonstrate that map inaccuracies can introduce significant
deviations in localization, with position errors increasing as the degree of randomization
increases. Although the cumulative distribution functions of the coverage map
(CDFs) for path gain remain relatively robust, the evaluation shows a clear degradation
in positioning accuracy with lower map fidelity. In particular, all ML-based
algorithms significantly outperform baseline approaches, providing marked improvements
in robustness and estimation accuracy under realistic conditions. The findings
confirm that careful algorithmic selection and robust handling of ray-traced data can
partially mitigate the negative effects of map imperfections.
This thesis provides actionable insights for the procurement, specification, and maintenance
of digital twin maps in industrial localization deployments, and highlights
the necessity of integrating advanced ML-based localization algorithms to maximize
reliability and operational value
Generating APIs through Library Learning using Large Language Models
No full textThe development of APIs in vehicular systems, such as trucks, is a manual and laborintensive process that involves multiple teams and iterative coordination, which makes it a prime candidate for automation. In this thesis, we develop a SPAPI Coder, a system that synthesizes high-level API endpoint implementations from low-level Controller Area Network (CAN) signals and OpenAPI specifications. Inspired by the manual workflow but restructured for automation using inductive program synthesis and library learning techniques, the system decomposes the manual software development workflow into three more manageable abstraction levels.
SPAPI Coder utilizes LLMs for code generation at each level while employing a Retrieval-Augmented Generation (RAG) pipeline for efficient and accurate mapping of API properties to CAN signals. The system features automated test script generation and execution for LLM-produced code, as well as LLM-assisted judging for evaluation.
The results of the study indicate that the proposed system can successfully generate functional API components if correct prompt engineering, library learning, and program synthesis techniques are used. While LLMs show promise as evaluators, their standalone accuracy for code evaluation tasks remains a limitation.
Findings suggest automating API development in complex domains like automotive systems using LLMs and program synthesis is viable. The approach feasibly addresses all dimensions of program synthesis and demonstrates the potential of library learning to automate API generation. It also provides a foundation for future work in incremental synthesis and intelligent software process automation