[dipl] Insinööritieteiden korkeakoulu / ENG

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  • Monitoring and Evaluating the Performance of an Energy-Efficient Newly Constructed Residential Apartment Building in Helsinki, Southern Finland
    (2025-05-25) Ajalin, Mimosa
     School of Engineering | Master's thesis
    The building sector plays a key role in climate change mitigation, accounting for around 40% of final energy use and 36% of energy-related emissions in the EU. As energy efficiency requirements become stricter, nearly zero-energy and zero-emission buildings are becoming the new standard in new construction. While many studies rely on simulations to evaluate energy performance, real-world monitoring of building operation is essential to validate the functionality of technical systems and indoor comfort in practice. This thesis focuses on the monitoring and performance evaluation of a newly constructed energy-efficient apartment building located in Helsinki, southern Finland. The main objective was to assess how well the building meets its energy performance targets, and evaluate if indoor environmental conditions remain within acceptable levels. The research method is based on the analysis of data collected from the building automation system. Energy flows, indoor temperatures, CO2 levels, and system-specific performance metrics were analyzed and compared to design targets. The monitoring results provide detailed information on the energy performance of the building. The actual measured energy consumption was compared to the simulated values from the design phase, which were calculated using weather data from the test reference year 2012. Although the heating degree days during the test reference year were 25% higher than during the actual measurement period, district heating consumption was 45% higher during the monitoring period. The electricity consumption of the ground source heat pump was 17% below the target, reducing the heat output and increasing the district heating demand. District cooling use exceeded the target by 48%, primarily due to the exceptionally hot summer in 2024. Of the solar electricity generated, 82% was utilized on-site, surpassing the target of 78%. Heat recovery from wastewater accounted for 17% of the energy required to heat domestic hot water. Over the one-year monitoring period, on-site production met 39% of heating demand (including heat pump electricity), 50% of cooling, and 17% of electricity use. Indoor environmental conditions were generally within acceptable limits, though occasional overheating were observed during the heating season.
  • Energiatehokkuusdirektiivin vaatiman energianhallintajärjestelmän käyttöönotto
    (2025-05-16) Astala, Arttu
     School of Engineering | Master's thesis
    To speed up the development of energy efficiency, the EU has imposed requirements on its member states through its revised Energy Efficiency Directive. The directive mandates companies with an energy consumption exceeding 85 TJ to implement an energy management system. The objective of this thesis was to explore how an energy management system can be implemented in the residential real estate business. The literature review of this thesis investigates legislation related to energy efficiency. The theoretical section also examines energy consumption in general in Fin- land and more specifically in buildings. The literature review focuses on the content, benefits, and challenges of three energy management systems: ISO 50001, EES+, and ISO 14001. The contents of the energy management systems are also compared in detail. The study examines the current state of energy management in the case company through a survey conducted among the personnel. A clear picture of the strengths and challenges of the company's energy management is formed, which allows the estimation of the workload required by the implementation of an energy management system. A workload cost analysis was conducted for the energy management systems to estimate their annual labor costs. Finally, the different system options were compared based on their costs and suitability. Based on this comparison, a recommended energy management system implementation plan was created, considering financial, time-related, and personnel resources. The thesis concluded that the most suitable energy management system for the case company is the national EES+ system. The most important factor in implementing the energy management system is to integrate the required measures into the or- ganization's existing operations as economically as possible. The main development areas for the case company will be in energy planning and in increasing awareness and communication related to energy efficiency.
  • Suomalaisen koulurakennuksen LVI-järjestelmien suunnittelu vahvan kestävyyden mallin mukaisesti
    (2025-05-15) Viemerö, Onni
     School of Engineering | Master's thesis
    Objectives: This study examines the sustainability of HVAC systems in school buildings, with a focus on carbon-intensive ventilation systems. The research investigates the effects of reducing carbon emissions on lifecycle costs and indoor climate at the early design stage. The aim is to integrate carbon emissions, economic considerations, and indoor climate while improving the understanding of carbon emissions in school buildings. Methods: The study consists of a literature review and a computational analysis. The calculations assess the life cycle carbon emissions, indoor air CO₂ -concentrations, thermal comfort based on Fanger’s PMV model, and life cycle costs for five different cases. The cases aim to minimize carbon emissions. Simulation tools are utilized to evaluate energy use and indoor climate. The objectives of parametric calculations are justified using a strong model of sustainability. Results and Conclusions: The carbon emissions from HVAC systems were divided into material-related emissions (33.72–41.90 %) and operational emissions (58.10–66.28 %). Material-related emissions were reduced by approximately 6 % without a significant impact on indoor air quality. Room-based ventilation control reduced operational emissions by 22 % compared to constant airflow control but initially degraded simulated indoor air quality at the beginning of occupancy periods. However, indoor air quality stabilized quickly during use. In contrast, zone-based control method reduced the carbon footprint by 10.5 % and had a smaller impact on indoor air quality than room-based control. Improving energy efficiency may therefore compromise indoor air quality. The ventilation control systems seemed to determine the feasibility of changes over the air handling unit. Overall, carbon emissions were reduced by about 17.9 %. Life cycle costs increased with energy use, whereas investment costs increased with decreasing carbon emissions. The PMV model results didn’t get better with increased energy use.
  • Talotekniikan hiilijalanjäljen ohjaus suunnittelun tarjousvaiheessa
    (2025-04-30) Viemerö, Taneli
     School of Engineering | Master's thesis
    This master’s thesis examined how the carbon footprint of construction projects can be influenced already during the design tender phase. The objective of the study was to explore how building services engineering solutions can be used to reduce a building’s carbon dioxide emissions at the earliest possible stage. The research focused particularly on HVAC (Heating, Ventilation, and Air Conditioning) systems, which constitute a significant share of a building’s energy consumption and emissions. The study applied a two-part research method: in addition to a literature review, qualitative research was conducted, consisting of a workshop and individual interviews. The workshop followed a Focus Group format and explored tender opportunities related to sustainability services. Based on the interviews, case examples were also created to evaluate different customer and tender scenarios. The research found that the share of building services in the lifecycle emissions of a building can be substantial — for example, in school buildings, the carbon footprint of building services can be the largest source of emissions. Furthermore, the study revealed that there is demand for additional sustainability services, such as carbon footprint calculation and guidance, but offering these services requires expertise and customer commitment. Barriers to providing such services include pricing models based on hourly rates and the fixed scope of tenders. Both the workshop and interviews concluded that carbon footprint guidance is most effective at the earliest possible design stage (pre-design/concept design), when changes can be made at a lower cost. As a result, the study demonstrated that building services engineering solutions can be used to influence emissions already at the tender stage, but the reliability of this guidance depends on the availability of information, professional expertise, and the sustainability goals of the customer.
  • Tiiliverhousjärjestelmän energiansäästöpotentiaali ja hiilijalanjälki verrattuna perinteiseen tiilimuuraukseen uudis- ja remonttikohteessa.
    (2025-05-30) Roos, Silja
     School of Engineering | Master's thesis
    The construction industry consumes about 40 % of all raw materials globally, and the built environment accounts for one-third of greenhouse gas emissions. Finland has committed to its national Climate Act, which aims for the country to be carbon neutral by 2035. This study examined and analyzed the life cycle carbon dioxide emissions of the Brix brick cladding system compared to fired clay brick in new and renovated apartment buildings. In the new construction case, the brick cladding system replaced traditional brick masonry in the exterior wall, and its slimmer profile resulted in increased living space and changes to other building components. The 1980s brick-clad exterior wall structure of the renovation site was replaced with a brick cladding system and a thermal plaster structure, including the insulation layers. The building’s annual heating energy demand was simulated using different exterior wall solutions in the IDA ICE software. The carbon dioxide emissions of the new building decreased by 17 % after the installation of the brick cladding system. However, the emission savings were moderate, mainly due to the additional intermediate, upper, and lower floors required by the increased living space. These added structures, with their high concrete content, accounted for 70 % of the carbon dioxide emissions of the altered materials. In the renovation building, the carbon dioxide emissions from the materials used in the brick cladding system were significantly higher than those of the other two options. However, due to the system’s lower annual heating energy demand, its total emissions were lower than the original brick cladding structure after 12 years. However, the carbon dioxide emissions from the thermal plaster structure exceeded the brick cladding system’s emissions only after 39 years. Using a brick cladding system instead of traditional masonry can significantly reduce lifecycle carbon dioxide emissions. Compared to conventional brick cladding, the system’s emissions are notably lower throughout an average facade’s lifespan. Key advantages of the brick cladding system include its lightweight structure, reduced material consumption, and good recyclability, offering practical and sustainable building solutions.
  • Hintakannibalisaatio suomalaisessa tuulivoimassa: Sijainnin vaikutus tuulivoimalla tuotetun sähkön hintaan
    (2025-04-30) Hatulainen, Veera
     School of Engineering | Master's thesis
    This thesis addresses the phenomenon of profit cannibalization in Finnish wind power. The profit cannibalization refers to a situation where wind power or other weather-dependent electricity production generates so much electricity simultaneously that the price of electricity is very low, and the resulting profit is very small. In 2024, Finland had 8358 megawatts of wind power. Most of it is in Western Finland, in Northern Ostrobothnia, Ostrobothnia and Southern Ostrobothnia. Project developers have shown increasing interest in building wind power in other parts of Finland, such as Lapland and Eastern Finland. This study investigated the impact of the location of wind power relative to the densest wind power on the occurrence of the cannibalization and whether a project located in a less dense wind power area could avoid cannibalization entirely or to a large extent. In the study, one V172-7.2MW wind turbine was modelled at 18 calculation points using the windPRO software. The year 2024 was used as the reference year, during which the share of existing wind power in electricity production was the highest, 24 percent of all electricity production. The temporal variation of the modelled production at each calculation point was multiplied by the electricity price at that moment, and the income was divided by the total yearly production of the point to obtain the weighted average price of electricity, known as the capture price. These prices were compared to each other and to the average wholesale price of electricity. The capture price was lowest in the densest wind power area of Western Finland. The lowest price was calculated at the point located in Pihtipudas, Northern Central Finland. The highest capture prices were in Southern Finland, Lapland and Kainuu. The difference between the lowest and highest capture prices was 36,3 percent. The capture price at all calculation points were below the average wholesale price, meaning that cannibalization was observed at all points. Additionally, the correlation of production between the lowest capture price calculation point and other points was calculated. The correlation was strong (over 0,7) at distances up to and around 200 km and decreased as the distance increased.
  • Julkisten kiinteistöjen ominaisuuksien vaikutukset ylläpitokustannuksiin
    (2025-05-21) Pietikäinen, Jesse
     School of Engineering | Master's thesis
    The maintenance costs of properties represent a significant portion of the total lifecycle costs of any real estate asset. In the public sector, the responsibility for providing services has led municipalities and cities to own a substantial amount of real estate, which should be maintained both efficiently and with high quality to support essential societal functions. Correspondingly, efficiency can be improved by un- derstanding the cost structure of properties. The aim of this study is to determine how well the characteristics of properties can explain the resulting maintenance costs. The research method used is multiple regression analysis, which allows for the variation in maintenance costs within the studied sample to be explained by several explanatory variables. As a foundation for the study, a literature review explores the institutional operating environment of real estate and facility management in the public sector and examines maintenance cost models found in the literature. The actual empirical research utilizes annual cost data provided by several municipalities. Based on the results, the gross floor area of a building accounts for the most significant portion of the resulting maintenance costs, both in absolute terms and in terms of unit costs. The age of the building, in turn, explains the variation in heating unit costs, particularly within a limited sample group. Based on these findings, the study provides an important starting point for standardizing cost structures in the public sector. A consistent data generating process enables the creation of more comprehensive maintenance cost models, which can offer essential insights to sup- port decision making.
  • Effects of remote work on offices in the Helsinki metropolitan area
    (2025-05-22) Issakainen, Janne
     School of Engineering | Master's thesis
    Remote and hybrid work are reshaping the commercial office landscape to accommodate the challenges brought on by changing work dynamics in the post COVID-19 era. While the transition was facilitated by the shock of the pandemic, it has been further solidified by changing employee expectations, technological advancements and emerg-ing remote and hybrid work strategies. These changes have driven rapid innovation in office design, space utilization, and organizational policy, all aimed at supporting a more flexible and resilient way of working. This thesis examines companies’ evolving office amenity preferences, requirements and remote and hybrid work strategies in the Helsinki metropolitan area (HMA). The rapid increase in remote and hybrid work has profoundly impacted perceptions of the role of office environments. No longer viewed solely as places for daily tasks, offices must now reinvent themselves to support the next generation of work by fostering collaboration, flexibility, and employee well-being. The research material was gath-ered by interviewing twelve organizations that had relocated, renovated, or reconfig-ured their office spaces between 2020 and 2030. These interviews were supplemented by a supporting questionnaire to provide additional context. The results show that companies are adopting new working styles, updating strategies, and reconfiguring office layouts to better support and embrace hybrid work. In response to these new realities, organizations are optimizing their spaces and enhancing the overall quality of the workplace. There is growing emphasis on the employee expe-rience and on the office’s evolving role as a space for collaboration and engagement. Facilitating meaningful interactions and ensuring seamless, modern office operations has become a strategic priority, shaping both policy and design decisions. Notable amenities identified in this research include one to two person meeting rooms, phone booths, communal areas and internal staircases designed to facilitate spontaneous interaction. The optimal level of office attendance varies depending on each organization’s operational needs and perspective on remote work. As flexible work models become more widespread, the demand for traditional, large, and outdated office buildings has declined. In contrast, high-quality office spaces are in greater demand, as companies prioritize flexibility, quality and efficiency over size, trading space for optimized and future-ready solutions. This thesis offers insights into how remote and hybrid work are transforming office use and the broader work environment. The findings are intended to inform stakeholders in real estate, urban plan-ning, workplace design and academia.
  • Neutronivuovärähtelyn mallintaminen turvallisuusanalyyseissä ja automaatiotoiminnoissa
    (2025-05-05) Andersson, Tommi
     School of Engineering | Master's thesis
    Prominent neutron flux fluctuations have been observed at Olkiluoto 3 nuclear power plant. This corresponds to fast variations in the amount of freely travelling neutrons and consequently in the power produced by fission. Strong neutron flux fluctuations cause problems in the usability of a nuclear power plant by, for example, triggering limitation systems. The variations caused by this phenomenon also create uncertainty in the deterministic safety analyses. The objective of this thesis is to develop a method to take the neutron flux fluctuations into consideration in process simulation of the power plant and furthermore in the safety analyses. To generate suitable stochastic noise, the properties of the neutron flux fluctuations are studied based on existing literature and analyzing the measurement results from the power plant. The required structures to the process model and a VAR model are developed so that generated artificial noise can be inserted into the Apros model. The fluctuations are introduced into the reactor’s hottest flow channel’s power distribution and the neutron flux measurement signals. The functionality of the developed methods is evaluated by analyzing the effects of the fluctuations in the process simulations when the reactor is at a steady state and during a transient following the loss of offsite power event. The functionality of the methods developed in this thesis can be stated to be acceptable based on the results obtained. However, some development areas were identified, such as problems in the determination of the thermal conductivity in the gas gap. As expected, low-pass filter like behavior is detected between the power produced in the fuel and the heat transfer from the fuel. Also, the model’s automation system’s response to the noise seems realistic. It is noted that the neutron flux fluctuations affect the results of the simulated transient considerably. The normalized measurement results’ distributions were found to retain their shape despite the changing magnitude of the fluctuations in different measurements. The skewness of these distributions was noticed to have similar spatial dependency as the standard deviation of the fluctuations.
  • Planning principles for sustainable adaptive traffic signal control – Comparison of tram priority strategies in Tampere
    (2025-05-26) Lampén, Elmo
     School of Engineering | Master's thesis
    This thesis studies planning principles for sustainable adaptive traffic signal control with a case study comparing tram priority strategies in Tampere. Earlier studies have compared current adaptive control and traditional traffic-responsive control both in terms of tram priorities and other features of traffic control. This study aims to find performance measures and planning principles for sustainability of adaptive control in addition to defining the most sustainable tram priority strategy between current absolute and potential conditional tram priority. In absolute priority, special request activates the priority phase while in conditional priority, program optimise the phase sequence using a cost function. Main research methods were microsimulation modelling and semi-structured expert interviews. The combination of qualitative and quantitative methods constructs an understanding of adaptive traffic signal control. Microsimulation modelling was used for testing different priority strategies and control policies while semi-structured expert interviews served as source of experiences and context to where this case adaptive control technology should be implemented, what policies practiced, and how well the adaptive control has reached the goals set to it in different locations. Results show that conditional tram priority performed weaker than absolute tram priority in terms of sustainability except the median cycle times of vehicle signal groups. The conditional tram priority weakened the tram headways too much and the absolute priority performed better. It is possible to shorten the average waiting times for other road users with conditional tram priority, but the reliability of it must improve to build a comparable test setup. The thesis suggests performance measures and steps for planning sustainable adaptive traffic signal control. The key to build successive adaptive control system is to develop the system iteratively in long term and in small steps to keep the risks moderate and learning fast together with the city, system provider, and other possible third parties.
  • The Impact of cannibalization on profitability of utility scale solar power in Finland
    (2025-05-20) Junkala, Aapeli
     School of Engineering | Master's thesis
    Solar power has historically played a minor role in the Finnish energy mix. However, this is about to change as in addition to the already existing 1 GW worth of residential and small commercial solar power installations, public plans for larger utility scale projects total to over 15 GW. Bringing even a fraction of the planned solar power online could have major implications in the market, namely through the cannibalization effect which decreases the power prices due to high supply during the day when the solar panels are producing power from the sun’s irradiation. This thesis aims to find how cannibalization effects the power prices in the upcoming years and what impact it has on the revenues of utility scale solar power plants. The historical cannibalization rate or how much the day ahead prices fall for each percent of solar power market penetration, is calculated with literature-defined method of using solar power’s value factors of the previous years’ data. Using the calculated cannibalization rate three power price scenarios with 1 GW, 2 GW and 3 GW of additional solar power capacity are created based on Nordpool day-ahead price data. The electricity generation of utility scale solar power plants with different configurations, with varying installation location, tilt and azimuth, are simulated with PVsyst software. The simulated generation profiles are combined with the day-ahead price data and the three scenarios to calculate revenues of the different configurations and additionally to find if cannibalization can be mitigated. According to the cannibalization rate calculation, the Finnish electricity market has experienced solar PV revenues decrease at a rate of 3 % per a percentage point of solar PV market penetration. Extrapolating this to scenarios with increased solar PV production capacity led to significant reductions in day-ahead prices, especially during times when the solar radiation is at its highest and the solar PV is at its most effective. The reduction in day-ahead pricing due to cannibalization is seen to directly reduce revenues of all the differently configured utility scale solar farms, with only slight relative differences in the revenue losses. The plant configurations with solar panels orientated to face South-East and sun tracking systems were found to be the best performers against cannibalization. However, the South-East facing systems as well as most other studied configurations lost more revenue due to sub-optimal orientation in respect to the sun than cannibalization itself, making them not suitable strategies for mitigating the effect of cannibalization.
  • Long-term commercial office leases in the aftermath of the covid-19 pandemic – Exploring the decision-making attributes of office occupiers influencing the long-term office relocations
    (2025-05-24) Tikkakoski, Janika
     School of Engineering | Master's thesis
    The Covid-19 pandemic disrupted traditional role of offices, accelerating the adoption of hybrid work and increasing demand for flexibility in office spaces. While market trends favor short lease agreements, some office occupiers continue to commit to long-term leases. This study seeks to understand the internal (company-specific) and external (market-specific) attributes influencing office occupiers’ decisions regarding long-term leases in the aftermath of Covid-19 pandemic. The study builds on location theories and previous research to examine attributes influencing relocation decisions. Qualitative methods were employed, including semi-structured interviews with seven office occupiers in the Helsinki Metropolitan Area (HMA) that signed long-term leases after the Covid-19 pandemic. Interview participants were involved in relocation decision-making processes. The findings reveal that the substantial size of the office occupier serves as a significant determinant influencing long-term relocation decisions. Office occupiers prioritize internal attributes such as corporate culture, collaboration, and employee attraction. External attributes like office layout and location accessibility are critical in supporting these priorities. Executive preferences and emotions often influence the decisions rather than rational analyses. Sustainability and services reflect mixed importance; some occupiers value them highly, while others see them as secondary or irrelevant. Costs are largely irrelevant due to downsizing; reduced office space enables occupiers to invest in premium solutions without escalating overall expenses. Long-term leases remain viable for large organizations due to the scale of projects, favorable landlord incentives, resource-intensive negotiation processes, and occupiers’ confidence in their future. This study addresses a gap in understanding office occupiers’ post-pandemic decision-making regarding relocation and the attributes influencing the decision-making. It highlights the significant role of behavioral location theory, emphasizing executive-driven preferences alongside traditional rational analyses. Moreover, this research offers insights for stakeholders in the real estate sector, including developers, property owners, and investors, by elucidating the attributes evaluated by office occupiers in the post-Covid-19 pandemic era when committing to long-term lease agreements.
  • Simulation study on the efficiency of solar tracker systems in Finland
    (2025-05-02) Hocksell, Aaro
     School of Engineering | Master's thesis
    The feasibility of solar tracker systems in large-scale solar photovoltaic power plants in Finland was studied. Excel and PVsyst software were used for electricity production simulations. Scientific literature was reviewed to as- sess the suitability of tracker systems for Finnish environmental conditions qualitatively. Two types of horizontal single-axis tracker systems were com- pared to a conventional fixed tilt system. Effect of location on the perfor- mance of each system was studied. Tracker systems were found to be more useful in areas with high irradiation levels. The best axis of rotation for a hor- izontal single-axis tracker was found to be around the north-south axis eve- rywhere in Finland. These types of tracker systems were found to have an advantage especially during summer, which increases the further north the power plant is located. Another possible advantage of them is the different production profile. Horizontal single-axis tracker systems’ technical disadvantages are re- lated to their lightweight structure, increased complexity and power con- sumption. The environmental factors that need to be considered when de- signing the tracker-based solar power plant are wind conditions, temperature and snowfall. Cold winter temperatures limit the power source options. Tracker systems can cope with snow loads more effectively than conven- tional fixed tilt systems. Aeroelastic instabilities caused by turbulent gusts are a significant environmental threat to tracker systems in Finland.
  • The implications of the social and healthcare reform on Finnish municipal real estate management
    (2025-05-26) Cavén, Matias
     School of Engineering | Master's thesis
    The Finnish reform of healthcare, social welfare and rescue services implemented in January 2023, transferred responsibility for organising these services from around 200 municipalities and municipal federations to 21 wellbeing services counties. As these services are mainly provided in municipal-owned buildings, municipalities have become major landlords across Finland. This thesis explores how the reform has impacted municipal real estate management (REM), and how the effects vary across municipalities of different sizes and resources. I surveyed 64 municipal decision-makers and combined the results with demographic and market data. The reform has introduced major challenges to municipal REM. While municipali-ties continue to own large social and healthcare property portfolios, counties now provide the services, creating a structural divide that brings uncertainty. Counties have delayed decisions on service networks and offered limited transparency in lease negotiations. As a result, 72% of municipalities view county plans as a threat to their properties, and only 11% feel well-positioned in lease negotiations. Of all respondents, 68% report that service reductions or centralisation will lead to vacant properties, lower rental income, and financial losses, ultimately harming service delivery and local vitality. Thus, 44% of municipalities plan to divest sur-plus properties. However, small rural municipalities face challenges due to weak investor interest. Repurposing care-specific buildings is also difficult. While real estate investments have grown in recent years, volumes would be high-er without reform-related uncertainty. Maintenance backlogs have increased, and major write-downs are expected nationwide. Municipal capacity to manage these challenges is limited by REM resources. Only 44% report sufficient expertise and staffing. Smaller municipalities often lack dedicated personnel, strategic planning, and electronic systems, leaving them less equipped for incorporation of property holdings, leasing, and facility management. However, the reform has also clearly pushed municipalities to reassess their property portfolios and improve aware-ness and expertise in municipal real estate.
  • Asuntomessualueen vaikutus asuntojen hintoihin – tapaustutkimus Tampere
    (2025-05-23) Ylitervo, Jenni
     School of Engineering | Master's thesis
    The aim of this thesis is to study whether the location of a house within a housing fair area affects its price, to what extent this effect may exist, and what factors influence the formation of housing prices. The research is conducted as a case study, focusing on the 2012 housing fair area in Vuores, Tampere. The thesis explores housing fairs, their main characteristics and history, as well as the Finnish housing market and the factors influencing housing prices. The impact of the housing fair area on housing prices is examined using linear regression analysis with the Ordinary Least Squares (OLS) method. The research data is received from the price monitoring service of the Federation of Real Estate Agency (Kiinteistönvälitysalan Keskusliitto Ry KVKL), which provides data on apartment transaction prices. The dataset includes sales of detached houses and row houses in Tampere from July 2012 through the end of 2024. The models were estimated using the whole sample as well as building age and postal code limited data. The research results contain considerable uncertainty, and based on the findings, it cannot be reliably stated that a price premium is paid for houses located specifically within the housing fair area. However, the results suggest that the overall residential area, which includes the housing fair area, may have a positive impact on housing prices. The reliability of the findings is significantly affected by the dataset used, which is limited in both the number of transactions and the scope of information. The data lacks detailed information about property features, which could have refined the study’s conclusions. Additionally, location characteristics were limited to postal code areas or the housing fair area boundary, and no other location-specific attributes were included.
  • Evaluating the dimensional measurement accuracy of fringe projection profilometry for manufacturing applications: A verification study using a custom reference artifact
    (2025-05-22) Zhang, Xinzhi
     School of Engineering | Master's thesis
    Three-dimensional (3D) metrology is the science of measuring objects in three dimensions to enable a digitization of measurement results. It has been serving as the foundation of evolution in manufacturing. This study was motivated by the increasing industrial need for fast, contactless 3D metrology solutions capable of handling complex geometries, where fringe projection profilometry (FPP) emerges as a promising solution. It is essential to verify the performance of FPP rigorously before it could be extensively adapted to manufacturing applications. This thesis investigates the dimensional accuracy of FPP measurement in manufacturing applications from multiple perspectives. A custom reference artifact incorporating linear distances, height variations, and spherical features was designed to verify the performance of the FPP scanner, GOM ATOS Core 200, in accordance with ISO 10360-13. Results were validated against high-precision tactile measurements obtained via a CMM and a cylindricity instrument. Two alignment approaches, cloud-to-cloud (C2C) alignment and sphere center (SC) alignment, were implemented to evaluate how alignment strategy influences measurement accuracy. Results proved that the scanner achieves high accuracy in measuring lengths and heights but not in reconstructing spheres. The measurements revealed a length-dependent deviation pattern that error tends to scale linearly with the measured length. Limitations were also observed at the edges of the scanner's measuring volume, highlighting reduced reliability in boundary regions. The findings in this thesis prove that FPP measurement is a promising solution for rapid, non-contact dimensional inspection in complex but non-critical geometries. The methodology and results of this verification study provide a fundamental reference for applying FPP measurement in industrial practice.
  • Kasvillisuuden muutokset Suomen suoyhdistymätyypeillä: Satelliittikuvapohjainen analyysi 24 vuoden ajalta
    (2025-05-17) Pirkola, Maija
     School of Engineering | Master's thesis
    Peatlands are not only significant carbon sinks but also play a crucial role in regulating the water cycle. They are diverse and heterogeneous ecosystems that respond to climate change in varying ways, depending on peatland type and local conditions. Despite their importance, peatlands have received less attention in remote sensing studies compared to, for example, forests. This thesis contributes to improving our understanding of boreal peatlands in Finland and their vegetation dynamics through the use of satellite-based data. This study examined changes in vegetation cover on undrained peatlands in Finland using NDVI (Normalized Difference Vegetation Index) data derived from MODIS satellite imagery for the period 2000–2023. Time series of monthly NDVI maximum values were analyzed using the remotePARTS analysis tool. Greening trends were observed on aapa and palsa mires in Lapland, while a slight browning trend was detected on concentric bogs in southern Finland. The study also explored the relationship between NDVI values and geographic coordinates (latitude and longitude) as well as summer temperatures. No association was found with latitude or longitude, but a slight negative correlation was observed between maximum NDVI values and summer temperatures for the same year. The results of this study indicate long-term changes in the ecosystems of the northernmost and southernmost peatlands. However, to draw reliable conclusions, further research is needed, which could utilize different vegetation index or satellite data.
  • Low metal loading core-shell electrocatalysts for the hydrogen evolution reaction: Activity, stability and system-level considerations
    (2025-05-26) Safarov, Oktay
     School of Engineering | Master's thesis
    The electrochemical bottleneck reaction in anion exchange membrane electrolysers (AEMEL) lies in the sluggish kinetics of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Addressing these challenges requires the development of efficient and stable electrocatalysts with tailored interfacial properties. As the primary objective of this work, palladium (Pd)-based catalysts supported on single-walled carbon nanotubes (SWCNTs) were synthesized and subsequently coated with conformal titanium dioxide (TiO2) layers using atomic layer deposition (ALD) to form well-defined core-shell nanostructures. The role of the TiO2 shell was investigated to understand its influence on HER activity and long-term stability. To enable reliable testing of these catalysts under AEMEL - relevant conditions, membrane electrode assembly (MEA) fabrication procedures were also evaluated as a secondary goal. Structural analysis confirmed the successful deposition of Pd and TiO2 on SWCNTs. The 14-cycle TiO2-coated sample (14C) exhibited the best electro-chemical performance toward HER, with a mass activity of 1.01 A/mgPd and an exchange current density of 0.173 A/mgPd, outperforming both the uncoated (0C) and commercial Pd/C catalysts. All performance metrics were normalized to the Pd content in each sample to enable a fair comparison. Stability testing utilizing a rotating disk electrode (RDE), and proton pump (PP) revealed a performance drop. After 15-hour chronoamperometry (CA) tests in the RDE setup, 0C lost ~45% of its initial activity, while 14C and 20C lost ~32% and ~35%, respectively. Post-stability scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) revealed Ti and O loss , suggesting TiO₂ detachment during CA. Due to the mechanical fragility of anion exchange membranes, optimizing the choice of porous transport layers (PTLs) was essential to prevent membrane damage and ensure system compatibility. The AEMEL tests revealed two major issues related to the choice of PTLs. First, the use of nickel foam (NF) on the anode side resulted in mechanical damage to the membrane during assembly, due to its rough and rigid surface, which led to punctures and internal short-circuiting. Second, while carbon paper (CP) provided a smoother interface and prevented physical damage, it suffered from chemical instability at cell voltages above 1.6 V, leading to progressive oxidation and carbon corrosion.
  • Enhancing Antarctic geodetic time series with non-tidal loading corrections
    (2025-05-23) Schulz, Aino
     School of Engineering | Master's thesis
    Polar regions are critical indicators of climate change, with Antarctica playing a central role due to its vast ice volume and sensitivity to environmental change. The Antarctic Ice Sheet is the largest on Earth and could raise global sea levels by up to 58 meters if fully melted. Although the East Antarctic Ice Sheet has been considered relatively stable, recent observations indicate increasing regional mass loss. These changes lead to crustal deformations that can be monitored using Global Navigation Satellite System (GNSS) time series. In addition to ice mass variability, GNSS data also captures surface displacements caused by atmospheric pressure, ocean loading, and hydrological redistribution, collectively known as non-tidal loading (NTL) effects. Correcting for NTL is especially important in Antarctica, where sparse station coverage and poorly constrained models can obscure geophysical signals. This study evaluates the availability and effectiveness of NTL corrections in East Antarctica, focusing on Dronning Maud Land (DML). GNSS time series from three datasets were analysed: two processed by external organisations, and one independently processed three-year test dataset. The impact of non-tidal atmospheric (NTAL), oceanic (NTOL), and hydrological (HYDL) loading corrections on noise characteristics, seasonal signals, and weighted root-mean-square (WRMS) values was assessed at three GNSS stations in DML: Aboa, Syowa, and Vesleskarvet. Results show that the effectiveness of NTL corrections depends on the dataset, correction model, and station. NTAL and NTOL corrections improved WRMS and noise levels in one external dataset, particularly in the vertical component. In contrast, the other external dataset generally showed degraded performance after correction, especially after applying HYDL, likely due to the limitations of hydrological models in ice-covered regions. The independently processed test dataset achieved the strongest WRMS and noise reductions, indicating that processing methodology and reference frame choices significantly influenced data quality. By assessing how NTL corrections and processing methodologies influence GNSS-data quality, this study shows that the vertical component in GNSS time series can be improved. These findings support improved estimates of ice mass balance, Glacial Isostatic Adjustment, and global sea-level rise projections.
  • Dronella ja laserkeilauksella tuotetun aineiston hyödyntäminen rautateiden kunnossapito- ja suunnitteluprosesseissa
    (2025-05-23) Liljestrand, Daniel
     School of Engineering | Master's thesis
    There is a constant need in railway planning and maintenance to find new technologies and innovative methods of doing. This research was conducted to enlighten, how utilization of drone and laser scanning operation can enhance planning processes and how these methods can bring more solutions and options especially for railway maintenance. The research used laser scanning and aerial photography as a method and the results that were produced using these methods provided the basis for this research. For the analysis phase, the research gathered the results together and analysed them using different kinds of photo editing software and point cloud processing software. In addition, the research also found out how these methods can be used as a tool in other construction industries and what kind of other methods are used in railway measurements and examination and how they are utilised. The research revealed that using laser scanning and aerial photography are efficient and useful ways to gather information and data about the changes in the railway environment and to detect deviations in railway infrastructure. Especially using the drone as an aerial photography tool brings efficiency to time management and cost management in these processes. In railway planning processes, these materials are capable of being used as a basis in creating terrain models in small railway projects or providing up-to-date aerial images from these project areas.