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  • 1.
    Abdelmageed, Rana
    Dalarna University, School of Information and Engineering.
    The implementation of a solar photovoltaic park with potential energy storage on SSAB's industrial area and its impact onthe internal electricity system2023Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The global push for increased renewable energy in power production is reshaping how industries approach energy systems. As the urgency to combat climate change grows, industries are integrating alternative power pathways alongside existing systems. This shift is driven by factors such as renewable energy adoption, energy storage advances, decentralization, electrification, circular economy principles, regulatory support, sustainability goals, and technological progress. These changes not only yield economic benefits but also enhance environmental and social impact. Integrating alternative pathways necessitates strategic planning, optimization, and a phased approach for seamless integration. Through these transformations, industries position themselves as sustainability leaders, align with climate goals, and ensure long-term energy security.

    The proposed implementation of a photovoltaic (PV) system at SSAB's steel production plant in Borlänge, specifically for forming line 4's electricity needs, will have a positive impact. This integration introduces renewable energy generation, offsetting the load and reducing reliance on the grid during peak hours, potentially leading to lower costs. It aligns with SSAB's environmental goals by curbing emissions, bolsters energy resilience, and aiding peak demand management. However, challenges in grid integration and infrastructure adjustments must be addressed for successful implementation. Overall, this move embodies SSAB's commitment to sustainability and efficient operations. 

    Through the utilization of simulation tools such as PVsyst and Homer Pro, an extensive study was conducted to investigate diverse scenarios involving combinations of a PV system, hydrogen modules, batteries, and a grid-connected load. The primary aim was to assess the feasibility of these scenarios within the energy system context. By leveraging PVsyst's capabilities for photovoltaic system analysis and Homer Pro's system optimization features, the study comprehensively examines interactions between electricity generation, storage, and consumption. This simulation-driven approach provided valuable insights into the performance dynamics, energy balance, and economic viability of each configuration, aiding in the informed selection of optimal combinations that align with the project's feasibility objectives.

    The results obtained suggest that the ideal size for the PV system in this context is 2.7 MW, allowing for an annual energy generation of 2.5 GWh. The electricity output aligns well with the yearly demand of 2.4 GWh for Forming Line 4

    The results from different scenarios offer valuable insights into how integrating renewable energy and incorporating energy storage affect the overall efficiency and cost-effectiveness of the system. Each scenario was assessed in comparison to the base case of grid connection, uncovering a spectrum of LCOE values. It is noteworthy that the highest LCOE, reaching 0.12 €/kWh, was observed when all renewable resources were combined, whereas the lowest LCOE, at 0.059 €/kWh, was achieved with the PV system-only configuration.

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  • 2.
    Abdulahad, Aziz
    et al.
    Dalarna University, School of Information and Engineering.
    Ohlsson, Martin
    Dalarna University, School of Information and Engineering.
    Analys av fuktsäkerhet hos hybridelement kontra sandwichelement2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is a thesis within the construction engineering program at Dalarna University in Borlänge. This thesis highlights the new hybrid element and its moisture-related properties, as well as comparing hybrid elements with the old proven solution of sandwich elements out of moisture perspective. This study is of interest as the construction industry needs new, more sustainable solutions that this hybrid element offers.

    The purpose of this study is to compare moisture properties of both sandwich and hybrid elements out of interviews and simulation of hybrid- and sandwich element with the help of a WUFI program. A further purpose is to analyse the behaviour of both elements when exposed to different amounts of moisture, investigate possible moisture-related problems in these elements and the possibility of building with hybrid elements instead of sandwich elements.

    The results of the study confirm that hybrid elements are theoretically an acceptable solution when it comes to moisture safety. At the same time, the conclusion concludes that a good tightness of a wall is an important parameter, but is not always enough to guarantee moisture safety, but tightness needs to be completed with careful design and execution.

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  • 3.
    Adolfsson, Alexander
    et al.
    Dalarna University, School of Information and Engineering.
    Ovesson, Christoffer
    Dalarna University, School of Information and Engineering.
    Utvärdering av sökmotorer i en svensk kontext2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The focus of this study was to evaluate different search engines on Swedish text. Information retrieval is widely used by both people and organizations, and it is important to be able to efficiently retrieve needed information at the right time. The study determined that relevance and speed are the most important factors in search engines. The evaluation measures the precision and recall which are relevance measurements, and speed of two search engines, Elastic search and MarkLogic. The evaluation has determined that there is no significant difference in the relevance of the retrieved results between the engines. The evaluation has also determined that there is a statistically significant difference in speed between the engines, with Elastic search outperforming MarkLogic. Both search engines performed very well in terms of successful searches, meaning to return a relevant document in the first 20 results. Both engines succeeded in fulfilling the information need 96% of the time.

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  • 4.
    Afzali, Faizullah
    et al.
    Dalarna University, School of Information and Engineering, Construction.
    Rashid, Renas
    Dalarna University, School of Information and Engineering, Construction.
    Främjande av återbruk av byggmaterial: En kvalitativ studie om branschens uppfattningar kring potentialen hos ekonomiska incitament2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper highlights the importance of economic incentives in stimulating the reuse of building materials in Sweden. Although the construction industry recognizes the benefits of reuse, the study shows that there are insufficient economic incentives to make it a standard practice. Through semi-structured interviews with representatives from the construction industry and a literature review, the study identified several barriers such as quality assurance, building regulations, lack of knowledge, and economic challenges.The purpose of the study was to investigate what economic incentives could promote the use of reused building materials and identify potential barriers to their implementation.The findings suggest that there are currently no direct economic incentives that encourage construction companies to reuse building materials. Several obstacles have been identified, including challenges related to quality guarantees, building regulations, lack of knowledge, and economic difficulties. The study also emphasizes that more extensive political and economic initiatives are needed to stimulate the use of reused building materials. The paper contributes to the existing research by providing recommendations to policy makers and other actors in the construction sector who are interested in promoting sustainability and environmentally friendly methods. It suggests that future research should focus on designing and testing specific economic incentives to promote the reuse of building materials. In its conclusions, it emerges that construction companies identify a multitude of obstacles and challenges when reusing building materials. It also appears that there is a noticeable lack of economic incentives from the state to promote the use of reused building materials in construction projects. Construction companies suggested different forms of economic incentives that could promote the use of reused building materials, including grants, tax relief, and digital platforms. There was also a variation in political opinions regarding the idea of introducing economic incentives to promote the reuse of building materials, with some supporting the idea and others opposing it.

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  • 5.
    Ahmad Nia, Pardis
    Dalarna University, School of Information and Engineering.
    Shading and natural ventilation, addressing indoor overheating in the present and future through the case study of Bysjöstrand eco-village2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Climate change temperatures expected to rise and extreme heat events (HW) canbe intensified. The influence of climate change on the built environment willbecame more apparent over the coming years. For example, there would be ashift in the risk of overheating in buildings, as well as the cooling and heatingneeds.Studies found that design strategies used to optimize buildings for winter like:good thermal insulation, high airtightness, and extra heat gains increase the riskof overheating. Thus, because of climate change, there is a need for checking thebuildings for summer conditions even in heating dominated countries.This study aims to investigate the potential of two main passive design strategiesto mitigate indoor overheating: ventilation and shading. The main focus of thisstudy is on single-family homes within the Swedish context. Bysjöstrand EkobyAssociation’s Bysjöstrand eco-village project is used as case study. 30 singlefamilyhomes are simulated using Honeybee to run EnergyPlus for calculatingindoor mean air temperature values, extracting the number of hour andpercentages of overheating for each building.Six alternative scenarios were used to evaluate the eco-village. The firststructures were assessed to determine the hours and percentage of time spentoverheating in the present and future situations. The second scenarios, whichinvolved utilizing natural ventilation, was tested to determine if and to what extentit can help to reduce the overheating risk in present and future.A combination of natural ventilation and shading was used for the last scenariosboth for current and future climate.According to the findings, natural ventilation has the greatest influence in reducingoverheating. Combining these two strategies in 2020 and 2070 can lower theaverage percentages of overheating from 17.5 % to 0.6 % and 52.8 % to 12.4%,respectively.The majority of the overheating risk may be addressed using passive strategies,based on the results. More detailed building design is likely be able to eliminateoverheating in single family homes, however, as this study showed it is importantto consider passive strategies from the early stage on the design process.

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  • 6.
    Ahmed, Omar
    et al.
    Dalarna University, School of Information and Engineering.
    Kelli, Philip
    Dalarna University, School of Information and Engineering.
    Analysing recommended content provided by YouTube and users preferences: A Case Study at Dalarna University in Sweden2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The application YouTube released in 2005 is today known as the most prominent platform on the world wide web for sharing, creating, and discovering video content(s). By utilizing technology trends such as Machine learning, YouTube can take advantage of algorithms such as deep neural networks to entice the users with a massive amount of personalized recommended content(s)t to watch based on the user's data.

    The algorithm in the YouTube recommendation system collects the users' personalized data such as location, watch history and search history to recommend video content. The YouTube recommendation system gives personalized recommended content(s) to a YouTube user with the collected data. The user may deem the recommended content as ethically wrong. Therefore, bring up meaningful discussions such as a YouTube consumer's sentiment towards those contents they deem unethical.

    This research study examines what ethical challenges exist in the YouTube recommendation system and how those challenges affect the YouTube consumers trust in the recommendation system.

    • The research questions that were examined in this study are: What kind of ethical challenges does the YouTube recommendation system have?

    • What kind of impact do those ethical challenges have on the user’s trust in the YouTube recommendation system?

    The respondents consisted of students at Dalarna University. This research was conducted with semistructured interviews and a questionnaire that consisted of 11 questionnaires.

    By examining the results from the literature reviews, interviews, and questionnaire, the gathered results show that challenges such as inappropriate, misinformed content and privacy exist with the YouTube recommendation system. Numerous of our respondents felt like they did not trust the YouTube recommendation system with their personalized data, primarily because of receiving video content that is not relevant, which has made some of the respondent question what YouTube does with the influx of the individual data.

    Based on the result it can be concluded that there are many concerns related to ethical issues in the YouTube recommendation system. In essence, the respondents highlighted the significance of privacy when using a platform such as YouTube. The respondents desired more transparency with their data.

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  • 7.
    Aldrin, Marcus
    et al.
    Dalarna University, School of Information and Engineering.
    Costello, Glenn
    Dalarna University, School of Information and Engineering.
    Wiklundh Engqvist, Mia
    Dalarna University, School of Information and Engineering.
    Studenters uppfattning av sin programtid: En fallstudie på kandidatprogrammet Informationsdesign2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background According to teachers for a higher education for a general degree, there is a perceived recurring problem that students who study a three-year bachelor's program do not understand how courses are connected to each other and that courses can be qualifying. What does the problem really look like from a student's perspective? Can what teachers describe be confirmed by students? How do they view their program time, how do they absorb information about their studies and how would they like to receive that information?

    Aim The purpose of the research study is to contribute knowledge about the type of information students in a higher education program need during their program time. The study's two questions are: What information do students need in order to understand their own program time? How can higher education institutions design information to support students' understanding of their own time in the program?

    Method The methods for collecting empirical data were questionnaires, semi-structured interviews and document analysis. The three years of the Information Designprogram at Dalarna University, together with documents such as study guides, syllabi, study plan and the information pages that are available to the students, have formed the empirical basis for the study. A total of seven interviews were conducted with students from these year groups.

    Results The study identified two main themes in relation to how students perceived the program, "Context / Identity" and"Understanding / Relevance". Recurring expressions of misunderstanding of how the content of the program is connected and an uncertainty about its end goal.

    Conclusion Students need the content of the education to be linked to the final goals of the program and to future working life.The program is perceived as very broad and difficult to grasp and that some courses need a clearer relevance to increase understanding, commitment and motivation. The study guide is a central document that should be partially standardized and contain specific information. An interactive solution over the program with filtering function is needed. 

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  • 8.
    Al-Dulaimy, Auday
    et al.
    Dalarna University, School of Information and Engineering, Informatics. Mälardalen University.
    Ashjaei, M.
    Behnam, M.
    Nolte, T.
    Papadopoulos, A. V.
    Fault Tolerance in Cloud Manufacturing: An Overview2023In: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST, Springer Science and Business Media Deutschland GmbH , 2023, p. 89-101Conference paper (Refereed)
    Abstract [en]

    Utilizing edge and cloud computing to empower the profitability of manufacturing is drastically increasing in modern industries. As a result of that, several challenges have raised over the years that essentially require urgent attention. Among these, coping with different faults in edge and cloud computing and recovering from permanent and temporary faults became prominent issues to be solved. In this paper, we focus on the challenges of applying fault tolerance techniques on edge and cloud computing in the context of manufacturing and we investigate the current state of the proposed approaches by categorizing them into several groups. Moreover, we identify critical gaps in the research domain as open research directions. © 2023, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

  • 9.
    Ali, Marwan
    et al.
    Dalarna University, School of Information and Engineering.
    Narani, Eema Sheykhi
    Dalarna University, School of Information and Engineering.
    Optimizing the Performance and Efficiency of District Heating Substations: A Study of the Cooling Process and Overall System Improvements in Ludvika2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The concept of future sustainability is driving efforts toward the efficient improvement of energy systems. District heating systems play a key role in balancing the energy system by improving performance and flexibility. As system efficiency increases, fuel consumption decreases, resulting in reduced greenhouse gas emissions and mitigating potential climate impacts, especially when using fossil fuels. In Sweden, district heating has shown significant growth, with a 75 % increase in total heat production over the last 30 years. Furthermore, carbon dioxide emissions have been reduced by approximately 50 % for each delivered kWh in the past 20 years, while renewable energy sources have doubled in the district heating sector. This thesis focuses on optimizing the cooling process to achieve lower return temperatures and higher system efficiency. It also emphasizes the importance of implementing an efficient heat consumption strategy to reduce peak loads and improve overall system efficiency. This approach involves managing demand to minimize peak heat requirements and distribute the load evenly throughout the day, leading to a more resource-effective and efficient system. The case study examines district heating supplied by VB Energy to Ludvikahem AB buildings, using data from Dec 2022 to Jan 2023. Quantitative data from district heating substations and the district heating plant are collected and analyzed to generate qualitative insights. The study proposes theoretical optimization measures based on the findings. The evaluation of substation performance reveals 20 poorly performing substations with various issues. Eight of these substations have technical problems related to substation components, while another eight experience management issues not aligned with specific activity profiles. The load shifting simulation demonstrates a 3% reduction in heat rate peak levels, resulting in approximately 7 kW of subscribed heat rate savings. Energy usage savings reach approximately 0.9%, leading to an increase in energy usage effectiveness. The cost savings amounted to about 3000 SEK over two months for a single building. This research emphasizes the importance of routine control, inspection, and documentation of substation performance to ensure optimal efficiency. Furthermore, indicates that the poorly performing substations that contribute to inefficiencies in the district heating network. Additionally, real-time regulation and load-shifting strategies are vital for optimizing customer consumption and maintaining an efficient district heating system, benefiting both suppliers and consumers.

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  • 10.
    Ali, Yalda
    et al.
    Dalarna University, School of Information and Engineering.
    Gunnarsson Sahlberg, Jonas
    Dalarna University, School of Information and Engineering.
    Förändringar och effekter efter implementering avRPA i mindre svenska kommuner2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Robotic Process Automation (RPA) is a wide variety of approaches and technical solutions that work as a support to automate repetitive tasks. In 2017, a new legislation was enacted in Sweden that made it possible for the public sector to automate decision support. This in turn led to more and more Swedish municipalities starting to implement RPA. Of Sweden's total 290 municipalities, 259 of them are classified as smaller municipalities. For these smaller municipalities, it is important to balance between having enough staff to manage both the finances and the tasks. In addition, several municipalities in Sweden cannot afford to hire new staff due to the current pandemic. Most of these smaller municipalities have not yet begun theirwork with RPA.

    The study examines six smaller Swedish municipalities that have implemented RPA with theaim of finding out the effects and changes that have arisen after their implementation. This has been done through semi-structured interviews to find out how their implementation went, what processes and in which areas they have chosen to automate and what they have seen for effects of this. Thematic analysis was then used to find patterns and themes in the interviews to present a common overall result with rich descriptions.

    This result showed successful implementations where the municipalities have come far different in their work and reached different levels of success, but where all through RPA have freed up time for their employees. These six municipalities also have a few processes to automate in the planning stage for the coming year.T

    he conclusion of this study shows that RPA gives good results for the smaller municipalities that have chosen to invest resources in it. In the absence of other ways to solve the current problems, RPA is a good method for balancing finance and the growing challenges for a smallermunicipality. 

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  • 11.
    Alkhuder, Juma
    et al.
    Dalarna University, School of Information and Engineering.
    Alnabhani, Mazen
    Dalarna University, School of Information and Engineering.
    A comparative study of the materials of Villa Zero project using LCA2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis a future-world case was undertaken of the life cycle assessment (from cradleto grave) of a single-family house. The house is expected to be constructed by the end of2021 in Borlänge, a city located in Dalarna County. The aim of this study is to investigatewhether the building materials in external walls and roof surpass in terms ofenvironmental impacts compared with other building materials suggested by the authorsof this thesis.Six scenarios were evaluated in terms of the environmental impacts for two buildingelements, external wall, and roof. A base case scenario is taken into consideration foreach building element, considering the fact, that the thermal performance characteristicsof the building materials are comprehensively provided. Consequently, four scenarios aredetermined by the authors.One Click LCA program was used to calculate the environmental impacts of thebuilding materials through the lifecycle of the house during a time horizon of 50 years.Hemp fiber insulation material is planned to be used in the external walls; thus, it isconsidered the baseline case for this thesis. The first study is corresponded to the externalwalls, and it was found that glass wool insulation is more environmentally friendly thanhemp fiber and rock wool insulation.Wood material is planned to be used in the roof; thus, it is considered the baseline casefor this thesis. The second study is corresponded to the roof, and it was found that woodmaterial is more environmentally friendly than concrete and steel.Therefore, the suggested material by the authors surpasses the baseline case materialenvironmentally in respect of external walls, but this was not the case regarding the roof.

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  • 12.
    Almlof, Erik
    et al.
    KTH Royal Inst Technol.
    Zhao, Xiaoyun
    Dalarna University, School of Information and Engineering, Microdata Analysis. KTH Royal Inst Technol.
    Pernestal, Anna
    KTH Royal Inst Technol.
    Jenelius, Erik
    KTH Royal Inst Technol, Div Transport Planning, Stockholm, Sweden..
    Nybacka, Mikael
    KTH Royal Inst Technol.
    Frameworks for assessing societal impacts of automated driving technology2022In: Transportation planning and technology (Print), ISSN 0308-1060, E-ISSN 1029-0354, Vol. 45, no 7, p. 545-572Article in journal (Refereed)
    Abstract [en]

    Numerous studies have studied the impacts of automated driving (AD) technology on e.g. accident rates or CO2 emissions using various frameworks. In this paper we present an overview of previous frameworks used for societal impacts and review their advantages and limitations. Additionally, we introduce the Total Impact Assessment (TIA) framework developed by the Swedish Transport Administration and use this framework to evaluate three scenarios for AD bus services in Stockholm. We conclude that the reviewed frameworks cover different aspects of AD technology, and that e.g. cybersecurity and biodiversity are areas largely neglected. Furthermore, most frameworks assume effects to be homogenous, when there may be large variation in e.g. perceived security. The TIA framework does not manage to include all societal aspects of AD technology, but has great benefits and manages to provide important insights of the societal impacts of AD technology, especially how effects may wary for different actors.

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  • 13.
    Amin, Solin
    et al.
    Dalarna University, School of Information and Engineering.
    Hellström, Johan
    Dalarna University, School of Information and Engineering.
    Can ChatGPT Generate Code to Support a System Sciences Bachelor’s Thesis?2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background ChatGPT is a chatbot released in November 2022. Its usage has grown to include being used in academia and for scientific writing, with varying results. We investigate if ChatGPT can be used for the technical part in a Bachelor’s thesis in System Sciences.

    Aim We evaluate if it is possible to generate the code for detecting potential gender bias in previous responses from ChatGPT, in the form of a dialogue.

    Method We use an exploratory case study where an iterative dialogue with ChatGPT is used to generate Python code to be able to analyse previous responses made byChatGPT. The methods for development were chosen by the authors from suggestions by ChatGPT.

    Results Two separate dialogues resulted in a program that combined a fine-tuned Natural Language Processing model together with sentiment analysis and word frequency analysis. The program successfully identified responses in the dataset as having a female or male gender bias or being gender neutral.

    Conclusions ChatGPT serves as a powerful tool for coding, although it currently falls short of being a one-stop solution that can generate code sufficient for more complex tasks witha single prompt. Our experience suggests that ChatGPT accelerates one’s work when the user possesses some programming knowledge. With further development, ChatGPT could transform coding workflows and increase productivity in related fields.

    Implications ChatGPT as a tool is very capable in supporting students in the technical aspect of a Bachelor’s thesis and it is not unreasonable to assume that it works in other contexts, as well. As such, one can achieve more with the tool than without, and consequently it would be for the better to integrate ChatGPT into thesis work. This stresses the point that we need to find better regulations for cheating and plagiarism.

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  • 14.
    Andersdotter, Julia
    Dalarna University, School of Information and Engineering.
    Improvement of an electrical coupler cover2022Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study was made for Dellner Couplers and is regarding a development of their electrical coupler cover (ECC).

    The electrical coupler includes several electrical contacts where the current flows, which lets electrical signals to be transported between all carriages in a train when the electrical couplers are connected to each other. An electrical coupler that is not connected to another one will have an ECC that automatically folds down in in front of the coupler to protect the electrical contacts from dust, water, and damage. The current ECC Dellner Couplers have today is made from an extruded aluminium profile, which has desirable properties in all aspects, except that it’s conductive.

    If the ECC encounter the electrical contacts, which can happen during a collision between the train and an animal, the contact between them could cause short circuit since the electricity is always running and can’t be turned off. The development of the ECC is aimed to remove the occurrence of short circuit in case of collision with an animal, but still fulfil the mechanical requirements.

    The method used to find a solution was based around well know concept development methods involving problem identification, identifying customer needs to create a target specification on what the ECC must fulfil, search for external and internal ideas for solving similar problems, performing concept screening on several concept ideas, and implement a finite element analysis (FEA) on the final concepts to see which one has the best potential for success. A part of the focus in the method has also been around material exchange by searching for potential materials in a material database.

    The results imply that adding thickness to the extruded aluminium profile could be a promising concept, which was discovered in the concept screening and FEA. The FEA of the concept shows lower displacement of the ECC and a decrease of stress level of about 57% compared to the original when being exposed to 10kN, and the result in displacement is ¼ of the original concept when being exposed to 100kN.

    The conclusion of this work is that a significant improvement can be made by adding thickness to the cross-section, but it is limited by the strength of the screws and the attachment. The ECC can handle up to 100kN before it will reach the electrical contacts, but the screws can only endure up to 53kN before they rupture. The screws and the attachment are the ones limiting what the electrical coupler can handle, but if the real force of an impact is below 53kN, this solution could be seen as acceptable in terms of the strength.

    The concept also involves a significant addition of weight and space required. The weight (+2,4kg) needs to be examined so it doesn’t affect other parts of the coupler negatively, and evaluation needs to be done to find out if the space required (+12mm at the center of the ECC) is available and that the meeting electrical couplers won’t collide in each other when connecting.

    A suggestion is to focus on the avoidance of short circuit, rather than the avoidance of reaching the electrical contacts. A more potential solution could potentially be found in a protective coating, which will allow the ECC to deform and not exhaust the screws and the attachment as much. The thicker and stronger geometry of the ECC will set higher requirements for the screws and the attachment. 

  • 15.
    Andersen, Martin
    et al.
    Dalarna University, School of Information and Engineering, Energy Technology. Dept. of Architecture and Civil Engineering, Chalmers University of Technology, Gothenburg.
    Bales, Chris
    Dalarna University, School of Information and Engineering, Energy Technology.
    Dalenbäck, J. -O
    Economic Analysis of Heat Distribution Concepts for a Small Solar District Heating System2022In: Energies, E-ISSN 1996-1073, Vol. 15, no 13, article id 4737Article in journal (Refereed)
    Abstract [en]

    One challenge in today’s district heating systems is the relatively high distribution heat loss. Lowering distribution temperatures is one way to reduce operational costs resulting from high heat losses, while changing the distribution system from steel pipes to plastic pipes and changing the heat distribution concept can reduce investment costs. The result is that the overall life cycle cost of the district heating system is reduced, leading to the improved cost competitiveness of district heating versus individual heating options. The main aim of this study was to determine the most cost-efficient distribution system for a theoretical solar district heating system, by comparing the marginal life cycle cost of two different distribution systems. A secondary aim was to determine the influence of the employed pipe type and insulation level on the marginal life cycle cost by comparing detailed economic calculations, including differences in pipe installation costs and construction costs, among others. A small solar-assisted district heating system has been modeled in TRNSYS based on a real system, and this “hybrid” model is used as a basis for a second model where a novel distribution system is employed and the heating network operating temperature is changed. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most efficient both from an energy and cost perspective. The total life cycle costs vary less than 2% for a given distribution concept when using different pipe types and insulation classes, indicating that the investment costs are more significant than operational costs in reducing life cycle costs. The largest difference in life cycle cost is observed by changing the distribution concept, the novel concept having approximately 24% lower marginal life cycle cost than the “hybrid” system. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 16.
    Andersen, Martin
    et al.
    Dalarna University, School of Information and Engineering, Energy Technology. Chalmers University of Technology, Gothenburg.
    Bales, Chris
    Dalarna University, School of Information and Engineering, Energy Technology.
    Dalenbäck, Jan-Olof
    Chalmers University of Technology, Gothenburg.
    Heat distribution concepts for small solar district heating systems – Techno-economic study for low line heat densities2022In: Energy Conversion and Management: X, ISSN 2590-1745, Vol. 15, article id 100243Article in journal (Refereed)
    Abstract [en]

    The high operating temperatures in today’s district heating networks combined with the low energy demand of new buildings lead to high relative network heat losses. New networks featuring lower operating temperatures have reduced relative heat losses while enabling an increase in the use of solar heat. The primary aim of this study was to determine if a particular district heating system can be made more effective with respect to heat losses and useful solar energy, by considering different distribution concepts and load densities. A small solar assisted district heating system with a novel hybrid distribution system has been modelled based on a real case study. This model serves as a basis for two other models where the distribution system and heating network operating temperature is changed. A secondary aim of the study was to determine the economic implications of making these changes, by using costs estimates to calculate the contribution of essential system components to total system cost. Results indicate that a novel distribution concept with lower network temperatures and central domestic hot water preparation is most energy efficient in a sparse network with a heat density of 0.2 MWh/m∙a and a performance ratio of 66%, while a conventional district heating system performs worst and has a performance ratio of less than 58% at the same heat density. In an extremely sparse network with heat density of 0.05 MWh/m∙a, the performance ratio is 41% and 30% for these systems, respectively. A simple economic analysis indicates that the novel distribution concept is also best from an economic point of view, reducing the initial investment cost by 1/3 compared to the conventional concept, which is the most costly. However, more detailed calculations are needed to conclude on this.

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  • 17.
    Andersson, Daniel
    et al.
    Dalarna University, School of Information and Engineering.
    Warnerfjord, Alexander
    Dalarna University, School of Information and Engineering.
    Påbyggnad med förstärkningstomme i befintlig byggnad: Konstruktionsval för invändig förstärkningsstomme av trä2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The different counties in Sweden have been reporting about the increasing housingshortage in the country for a long time. To counteract this shortage, 60 000- 70 000residences need to be produced yearly in Sweden till 2029. In the 60s-70s Swedenalso faced big challenges with housing shortage due the urbanization from thecountryside of Sweden to the cities. The result was to build on a large scale in aIndustry-like ways and the consequences of this was that green areas around thecities were exploited to make room for new residential areas. To not repeat thehistory again an alternative option could be to densify the already built urbanenvironment with for example building extensions.In an already existing urban environment, there are many different types ofbuilding, this also means that there are many different types of extensions. Thepurpose of the work is to: for a reference house located in the central area of Falun,find an alternative way for a building extension in wood where the already existingbuilding is not added by any load from the extension. Another purpose with thework is therefore to contribute with knowledge around the subject, buildingextensions in wood.The building that has been the starting point of this work is located in the centralarena of Falun and was built in the late 60s. The building extension that the projectcame up with is of “light construction” and the reinforcement frame in massivewood technique with columns and beams. The reason why to use a real referenceobject is to give the work a real construction to relate to when analyzing thepossible placing of the columns. The dimensioning of the building extension andthe reinforcement frame is done with manual calculations that are based on theapplicable rules in Sweden, Eurocode and EKS. The building has also beenmodeled in Revit to give an illustration on the building extension with thereinforcement frame but also the building in its entirety after the buildingextension.The result of the reinforcement frame is in many ways similar to a “trä8”-system.Columns and beams take the vertical load and the existing buildings system ofjoist, walls and stairwells in concrete contribute to the frame stability. Throughanalyzing the drawing of the existing building, the placement of the columns hasbeen done according to different parameters. The beams that are placed on top ofthe columns have then been controlled for the current spans with the current loadsfrom the manual calculations of the building extension. The result and theconclusions that can be done from this work is that the construction's critical partis the beams placed on the columns and not the columns itself. The dimensions ofthe beams are crucial for how many floors that are possible to build on thecolumns that are placed. Also, the weight of the building extension has an impactin the quantity of the columns and therefor longest spans for the beams

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  • 18.
    Andersson, Jens
    et al.
    Dalarna University, School of Information and Engineering, Information Systems.
    Berg, Marcus
    Dalarna University, School of Information and Engineering, Information Systems.
    Klassificering av refuger baserat på spatiala vektorpolygoner i vägnät: En fallstudie om utmaningar och lösningar till att klassificera företeelser till det norska vägnätet2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Geographical information systems are becoming increasingly important in today´s society where spatial data can be stored, collected, analysed, and visualized. By compiling spatial data reality can be abstracted. Detailed information on road networks and objects (traffic islands, noise barriers, signs, etcetera) for analysis leads to more efficient operation and maintenance work. Which in turn provides increased accessibility for road users. The technology company Triona has a map application where algorithmic connection of traffic islands (Norway-dataset) to the Norwegian road network has been challenging. A traffic island is an elevation in the street that delimits lanes and is reminiscent of a sidewalk in appearance. This case study addressed a sub-problem where classification of traffic islands could facilitate the connection and prerequisites for analysis. The aim was to present methods that could classify the traffic islands with supervised machine learning. With the algorithms K-nearest neighbors (KNN) and Decision tree, the possibility of automatically classifying the traffic islands was studied. A traffic island consisted of a vector polygon which is a list storing its corners (latitude and longitude). The Norway-dataset was not previously labelled into its eleven types. A data collection of 2157 refuges with seven types from Portland, USA was therefore applied instead. The traffic islands were transformed with Elliptical Fourier Descriptors which extracted an approximation of its contours to train the machine learning models on. Conclusions could be drawn by analysing the contours and observing performance. Performance was evaluated based on accuracy with precision and recall on the Port-land-dataset. Accuracy is the proportion of correct classifications. KNN achieved 64% and Decision Tree 69% accuracy. As both datasets contained real traffic islands in road networks, an assumption could be made that the accuracy would not be much higher if applied on the Norway-dataset. The result was not considered sufficient for a recommendation.

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  • 19.
    Andersson, Julia
    et al.
    Dalarna University, School of Information and Engineering.
    Liedström, Matilda
    Dalarna University, School of Information and Engineering.
    Effekten av olika logistiklösningar: En studie kring fördelar och nackdelar med tredjepartslogistik och inbärning till ett projekt i Dalarna2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Within the construction industry the advantages of looking at the logistics todifferent projects has been acknowledged during the past couple of years.This study has been written in collaboration with Skanska Sverige AB. Thepurpose of the study is to, in different ways, examine what advantages anddisadvantages there are in using the logistics solutions terminalization (also knownto be a part of Third Party Logistics) and inside delivery to a specific project inDalarna, Sweden. This project is a remodeling project of a school with studentsfrom six to sixteen years old. Within the school area new parts of the school isbuilt while students are located in the yet existent buildings. This infer thatstudents move around the construction sites daily. The study also involves thirdparty people and how these people feel about the large transports connected to theproject. The inside delivery utility is then discussed based on the securityexperience within and around the construction site along with the economic andecological perspective of the service.The methods used in this study are interviews with three people of the projectmanagement, one person that works with logistics at the company, the headmasterof the younger students, skilled workers and third party people. Furthermore afield study is done that includes measurements and observations. As a close,calculations are done to determine if a economical profitability could be possibleby using inside delivery.Results from the study show how the logistics solutions terminalization and insidedelivery is looked at within Skanska today. Here, the advantages anddisadvantages with the different services are displayed from the perspectives of thepeople who were interviewed. The results from the measurements from the fieldstudy presents how many third party people that move adjacent to the two activeconstruction sites when the school day begins. The calculations show that it iseconomically beneficial to use inside delivery after the end of the workday whileused with terminalization.Conclusions of the study indicate that there are no overall solutions regarding howthe logistics must be used in different projects. If there is a possibility to use terminalization in the area where the project is situated, this, along with insidedelivery, is a good alternative for the project.

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  • 20.
    Andersson, Mattias
    et al.
    Dalarna University, School of Information and Engineering, Informatics.
    Marshall Olsson, Tom
    Dalarna University, School of Information and Engineering, Informatics.
    ChatGPT as a Supporting Tool for System Developers: Understanding User Adoption2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: AI, specifically conversational AI like OpenAI's ChatGPT, is rapidly expanding in personal and professional settings, offering cost-cutting and modernization opportunities for businesses. This technology, capable of simulating human-like conversations, holds promise across various industries, potentially enhancing productivity through human-AI collaboration. The main research problem is to identify factors influencing system developers' adoption of ChatGPT, considering its design and implementation to mitigate potential negative impacts. Aim: This study aims to investigate the factors that influence user adoption of ChatGPT as a tool to support system developers. Additionally, it aims to identify how ChatGPT can aid system developers in their daily work, and challenges associated with incorporating ChatGPT in this context. Method: Using a case study approach with qualitative and quantitative data collection methods, the study employs positivist and interpretivist philosophical paradigms. Results: Results showed that the perceived ability of ChatGPT to enhance efficiency and generate accurate responses significantly impacts adoption intentions. When examining aspects related to timesaving, productivity enhancement, and user-friendliness, no statistically significant results were found. Among developers, ChatGPT is considered valuable for simplifying tasks and assisting junior developers. There are concerns regarding its capability to handle complex tasks and potential security issues. Suggestions for improvement include better integration with integrated development environments (IDEs) and enhanced accuracy. Conclusions: The findings highlight perceived accuracy and efficiency as driving factors for user adoption regarding ChatGPT. ChatGPT can support tasks like debugging, code generation, code refactoring, code optimization, and technical documentation. However, there may be some potential limitations when dealing with overly complex code. Barriers to adoption include concerns about integrity and security, lack of awareness, and functional limitations. Implications: The insights gained can indirectly benefit companies, including our business partner CGI, by guiding decision-making processes related to the effective adoption and utilization of ChatGPT.

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  • 21.
    Andersson, Michael
    et al.
    Dalarna University, School of Information and Engineering.
    Hysing Berg, Robert
    Dalarna University, School of Information and Engineering.
    Docker Container Images: Concerns about available container image scanning tools and image security2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With the growing use of cloud computing and need for resource effectiveness, the use of container technology has increased compared to virtual machines. This is since containers require fewer resources and are significantly faster to start up. A popular containerplatform is Docker which lets users manage and run containers. The containers are run from images that can be downloaded from different sources, Docker Hub being a popular choice. Because of container technology sharing the OS-kernel with the host, there is a great need to increase and monitor the security of containers and the images they are run from. To find vulnerabilities in images, there are image scanning tools available. In this dissertation, we study 5 different image scanning tools and their performance. Twentyfive random images were selected from popular images on Docker Hub and were then scanned for vulnerabilities with the tools in the study. We aimed to answer the following questions: (1) Are there any clear differences between the number of vulnerabilities found by different image vulnerability scanning tools? (2) Are there any differences between the types of vulnerabilities found by different image vulnerability scanning tools? (3) What is the relative effectiveness of different image vulnerability scanning tools? The results show that there are considerable differences between different container image scanning tools regarding the number of found vulnerabilities. We also found that there were differences regarding the severity-grading of found vulnerabilities between the tested tools. When using our proposed metric for calculation of relative effectiveness, we discovered that the tool with the highest relative effectiveness could still miss approximately 39 percent of the vulnerabilities in images. The tool with the lowest relative effectiveness could miss approximately 77 percent of the vulnerabilities in images. 

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  • 22.
    Andersson, Mikael
    et al.
    Dalarna University, School of Information and Engineering, Construction.
    Barrioz, Gabriel
    Borlänge kommun.
    Nordström, Louise
    Borlänge kommun.
    Ranhagen, Ulf
    Dalarna University, School of Information and Engineering, Construction.
    Svensson, Tony
    Dalarna University, School of Information and Engineering, Construction.
    Rönnelid, Mats
    Dalarna University, School of Information and Engineering, Energy Technology.
    Energiinnovation Jakobsdalen: Workshopserie hösten 20212022Report (Other academic)
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  • 23.
    Andrén, Axel
    et al.
    Dalarna University, School of Information and Engineering.
    Kashlan, Ghaith
    Dalarna University, School of Information and Engineering.
    Nantarat, Atichoke
    Dalarna University, School of Information and Engineering.
    Improving Email Security in Organizations: Solutions and Guidelines2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Data breaches from email attacks have been an issue since email was first implemented. Common attack methods like phishing are still a threat to organizations to this very day. That is because it never seems to stop evolving and keeps becoming more and more convincing. Email compromises have caused billions of dollars in damage worldwide, and it shows no sign of stopping. The purpose and research questions of this thesis are formulated to find guidelines or solutions that organizations can follow to improve their overall email security and awareness. In this thesis, both a systematic literature review and interviews are methods used to conduct the research. That way, both the technical portion of the subject, as well as the human perspective are covered. We found that the most common and significant email threats to organizations are phishing, BEC, and APT attacks. This thesis provides methods to mitigate these threats. What has also become clear is that human mistakes are a large portion of the problem concerning email attacks.

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  • 24. Anglart, D
    et al.
    Emanuelson, U
    Rönnegård, Lars
    Dalarna University, School of Information and Engineering, Statistics.
    Sandgren, C Hallén
    Detecting and predicting changes in milk homogeneity using data from automatic milking systems.2021In: Journal of Dairy Science, ISSN 0022-0302, E-ISSN 1525-3198, Vol. 104, no 10, p. 11009-11017Article in journal (Refereed)
    Abstract [en]

    To ensure milk quality and detect cows with signs of mastitis, visual inspection of milk by prestripping quarters before milking is recommended in many countries. An objective method to find milk changed in homogeneity (i.e., with clots) is to use commercially available inline filters to inspect the milk. Due to the required manual labor, this method is not applicable in automatic milking systems (AMS). We investigated the possibility of detecting and predicting changes in milk homogeneity using data generated by AMS. In total, 21,335 quarter-level milk inspections were performed on 5,424 milkings of 624 unique cows on 4 farms by applying visual inspection of inline filters that assembled clots from the separate quarters during milking. Images of the filters with clots were scored for density, resulting in 892 observations with signs of clots for analysis (77% traces or mild cases, 15% moderate cases, and 8% heavy cases). The quarter density scores were combined into 1 score indicating the presence of clots during a single cow milking and into 2 scores summarizing the density scores in cow milkings during a 30-h sampling period. Data generated from the AMS, such as milk yield, milk flow, conductivity, and online somatic cell counts, were used as input to 4 multilayer perceptron models to detect or predict single milkings with clots and to detect milking periods with clots. All models resulted in high specificity (98-100%), showing that the models correctly classified cow milkings or cow milking periods with no clots observed. The ability to successfully classify cow milkings or cow periods with observed clots had a low sensitivity. The highest sensitivity (26%) was obtained by the model that detected clots in a single milking. The prevalence of clots in the data was low (2.4%), which was reflected in the results. The positive predictive value depends on the prevalence and was relatively high, with the highest positive predictive value (72%) reached in the model that detected clots during the 30-h sampling periods. The misclassification rate for cow milkings that included higher-density scores was lower, indicating that the models that detected or predicted clots in a single milking could better distinguish the heavier cases of clots. Using data from AMS to detect and predict changes in milk homogeneity seems to be possible, although the prediction performance for the definitions of clots used in this study was poor.

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  • 25.
    Apelman, Jonas
    et al.
    Dalarna University, School of Information and Engineering.
    Johnson, Konrad
    Dalarna University, School of Information and Engineering.
    Informationsdesign i kristid: Regioner och effektiv kommunikation genom Instagram2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background At the end of 2019 the spread of the SARS-CoV-2 virus began in China. Inorder to stall the spread of the virus, government agencies in Sweden havefaced a challenge with communica<ng informa<on in an effec<ve way. Oneway to reach a large number of people is through social media.Aim The study analyzed how three local government agencies had used Instagramto convey informa<on about the pandemic to their ci<zens. As well aswhat strategy has worked the best.Method Interviews were conducted in order to find out how the regions saw theirown work and goal with their use of Instagram. To accompany the interviews,an online form was used to pinpoint the target audience's aVtudetowards different types of Instagram posts. Together with a mul<modalanalysis of the posts, a triangula<on of the results was made.Results The strategies, target groups and goals with Instagram varied between theregional government agencies. Certain mul<modal strategies like culturalsymbols, analy<cal processes and textual metafunc<ons can have a posi<veimpact on the ci<zens aVtude towards the posts. It also showed the difficultywith designing informa<on for Instagram in a way that encourages citizensto read the post in its en<rety. This was especially prominent whenusing cultural symbols in a careless way or the message conveyed by theimage was perceived to be irrelevant. Finally, it showed that the local governmentsaim to follow the governmental wri<ng guidelines but don’t alwayssucceed.Conclusions The target audience and purpose of using Instagram varies between the regionalgovernment agencies and this is reflected in their mul<modal execu-<on of Instagram posts. Regional governments need to be aware that themessage of the image and the use of cultural symbols can have a nega<veimpact on the ci<zens' will to understand the content of the post.

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  • 26.
    Aras, Diyar
    Dalarna University, School of Information and Engineering.
    Byggfel i produktion: Vanligaste uppkommande byggfelen i byggprocessen2023Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Byggfel vid upprättande av byggnationer genomsyrar byggbranschen och står för onödigt höga kostnader av den totala byggkostnaden. Denna problematik har under de senaste åren uppmärksammats markant av både aktörer inom byggbranschen, samt av samhället. Enligt en rapport upprättad av Boverket (2022) uppnår dessa kostnader närmare 100 miljarder kronor och därmed sänker värdigheten i de investerade pengarna. Syftet med denna rapport är att upplysa problemområdet, och utifrån samverkan med aktörer som är delaktiga i byggprocessens olika skeden, försöka undersöka vilka byggfel som är vanligast och vart dess brister uppkommer. Utifrån det som påvisas så ska konkreta åtgärder och förbättringstips lyftas fram. Syftet och frågeställningarna i rapporten förväntas besvaras och uppnås via kvalitativa studier. Dessa studier kommer att upprättas i from av intervju och litteraturstudie. Intervjuerna kommer att hållas med aktörer inom byggbranschen som medverkar i byggprocessens olika skeden, detta urval ska ge möjligheten att få tankar och idéer utifrån olika synvinklar. Byggfelen som anses vara vanligast förekommande är fukt och vattenrelaterade skador, samt montering och infästning. Denna typen av skador uppkommer på olika platser i byggnationer, men främst i badrum och våtrum, takfönstermontering, fönsterdörrar och tyngre dörrar. De bakomliggande orsakerna till uppkomsten av dessa skador är bristande i kunskap, erfarenhet och tidspress. Bristande kunskapen och erfarenheten anses vara en central faktor i både projekteringen och produktionen, medan tidspressen framhävs tydligast i produktionsfasen. För att få bukt med byggfel-problematiken krävs det specifika enskilda åtgärder för de olika problemområdena genomförs. Ansvarstagandet hos de olika aktörerna i byggbranschen behöver öka, både i planering, utförande och kravsättning.

  • 27. Ardestani, Seyed Faraz Mahdavi
    et al.
    Adibi, Sasan
    Golshan, Arman
    Dalarna University.
    Sadeghian, Paria
    Dalarna University, School of Information and Engineering, Microdata Analysis.
    Factors Influencing the Effectiveness of E-Learning in Healthcare: A Fuzzy ANP Study2023In: Healthcare, E-ISSN 2227-9032, Vol. 11, no 14, article id 2035Article in journal (Refereed)
    Abstract [en]

    E-learning has transformed the healthcare education system by providing healthcare professionals with training and development opportunities, regardless of their location. However, healthcare professionals in remote or rural areas face challenges such as limited access to educational resources, lack of reliable internet connectivity, geographical isolation, and limited availability of specialized training programs and instructors. These challenges hinder their access to e-learning opportunities and impede their professional development. To address this issue, a study was conducted to identify the factors that influence the effectiveness of e-learning in healthcare. A literature review was conducted, and two questionnaires were distributed to e-learning experts to assess primary variables and identify the most significant factor. The Fuzzy Analytic Network Process (Fuzzy ANP) was used to identify the importance of selected factors. The study found that success, satisfaction, availability, effectiveness, readability, and engagement are the main components ranked in order of importance. Success was identified as the most significant factor. The study results highlight the benefits of e-learning in healthcare, including increased accessibility, interactivity, flexibility, knowledge management, and cost efficiency. E-learning offers a solution to the challenges of professional development faced by healthcare professionals in remote or rural areas. The study provides insights into the factors that influence the effectiveness of e-learning in healthcare and can guide the development of future e-learning programs.

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  • 28.
    Arumugam, Vijay
    Dalarna University, School of Information and Engineering.
    Techno-economic study of second-life EV batteries as alternative energy storage and comparison with lead-acid and new Li-ion batteries in off-grid PV systems2022Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The global EV stock is expected to increase from 7.2 million in 2019 to nearly 140 million vehicles by 2030. So, the demand for the battery also increases due to the increase in the number of EVs. In any EV, battery degradation is an unavoidable phenomenon and EV batteries are assumed to arrive at their end-of-life in EV application when the state of health reaches 80 %, repurposing the eligible EV batteries after end of first life is expected to extend their lifetime by another 5-15 years in the second life applications. 

    This thesis aims to conduct a techno-economic study on the usage of second life EV batteries as an alternative storage option in off-grid PV systems compared to lead-acid batteries and new Li-ion batteries. A single-family house with an annual demand of 2245 kWh/year located in Athens was chosen as the primary location, the off-grid PV system is pre-sized for Athens and based on the pre-sizing results and what is state of art in the market. The system components were chosen for system design (4 kW bi-directional inverter, 2.9 kW PV array, 7.2 kW genset and three battery bank options i.e., 16.5 kWh of lead-acid, 8 kWh new Li-ion and 12.6 kWh of second life EV battery). PV off-grid system with different storage options is simulated using HOMER for both locations and the results are compared. 

     The simulation results show that the designed off-grid PV system can reach a solar fraction of 90 % in Athens and 73 % in Gotland when 16.5 kWh of lead-acid batteries are used with an allowed depth of discharge of 50 %. When a new Li-ion battery of 8 kWh with an allowed depth of discharge of 80 % is used then the achievable solar fraction is 84 % in Athens and 71 % in Gotland, When the second life EV battery of 12.6 kWh with an allowed depth of discharge of 60 % is used then the achievable solar fraction is 90 % in Athens and 74 % in Gotland. Sensitivity analysis is performed on the depth of discharge and results showed that the solar fraction can be increased by allowing the battery to discharge more, but it also decreases the battery lifetime. 

     The simulation results also show that the net present cost was lower in Athens for all the reference cases compared to Gotland. Net present cost and levelized cost of electricity for the off-grid system are 25.3 k€, 0.9 €/kWh in Athens and 29.2 k€, 1.0 €/kWh in Gotland when a lead-acid battery is used. When a new Li-ion battery is used then 26.2 k€, 0.9 €/kWh in Athens and 29.3 k€, 1.0 €/kWh in Gotland, when the second life EV battery is used then 26.7 k€, 0.9 €/kWh in Athens and 30.7 k€, 1.1 €/kWh in Gotland. 

     Overall, the net present cost and levelized cost of electricity are lower in Athens in all cases compared to Gotland. For the reference house in Athens, lead acid battery system has shown slightly lower net present cost than new Li-ion battery and second life EV battery. For the reference house in Gotland, both lead acid battery and new Li-ion battery system have shown similar net present cost and they are slightly lower than second life EV battery.  

    Also, the second life EV battery levelized cost of electricity is fairly comparable to the new Li-ion and lead acid battery system. In future, the massive inflow of used batteries from EV are expected to be available on the market for the second life application at a lower price than today. Thus, in future, second life EV batteries can become economically viable.

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  • 29. Arya, N.
    et al.
    Chandran, Y.
    Luhar, B.
    Kajal, P.
    Powar, Satvasheel
    Dalarna University, School of Information and Engineering, Energy Technology. Indian Institute of Technology, Mandi, Himachal Pradesh, India.
    Balakrishnan, V.
    Porosity-Engineered CNT-MoS2 Hybrid Nanostructures for Bipolar Supercapacitor Applications2023In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 15, no 29, p. 34818-34828Article in journal (Refereed)
    Abstract [en]

    Bipolar supercapacitors that can store many fold higher capacitance in negative voltage compared to positive voltage are of great importance if they can be engineered for practical applications. The electrode material encompassing high surface area, better electrochemical stability, high conductivity, moderate distribution of pore size, and their interaction with suitable electrolytes is imperative to enable bipolar supercapacitor performance. Apropos of the aforementioned aspects, the intent of this work is to ascertain the effect of ionic properties of different electrolytes on the electrochemical properties and performance of a porous CNT-MoS2 hybrid microstructure toward bipolar supercapacitor applications. The electrochemical assessment reveals that the CNT-MoS2 hybrid electrode exhibited a two- to threefold higher areal capacitance value of 122.3 mF cm-2 at 100 μA cm-2 in 1 M aqueous Na2SO4 and 42.13 mF cm-2 at 0.30 mA cm-2 in PVA-Na2SO4 gel electrolyte in the negative potential window in comparison to the positive potential window. The CNT-MoS2 hybrid demonstrates a splendid Coulombic efficiency of ∼102.5% and outstanding stability with capacitance retention showing a change from 100% to ∼180% over 7000 repeated charging-discharging cycles. © 2023 American Chemical Society.

  • 30. Arzpeyma, N.
    et al.
    Alam, Moudud
    Dalarna University, School of Information and Engineering, Statistics.
    Gyllenram, R.
    Jönsson, P. G.
    Model development to study uncertainties in electric arc furnace plants to improve their economic and environmental performance2021In: Metals, ISSN 2075-4701, Vol. 11, no 6, article id 892Article in journal (Refereed)
    Abstract [en]

    A statistical model is developed in order to simulate the melt composition in electric arc furnaces (EAFs) with respect to uncertainties in 1) scrap composition, 2) scrap weighing and 3) element distribution factors. The tramp element Cu and alloying element Cr are taken into account. The model enables simulations of a charge program as well as backwards estimations of the element concentrations and their variance in scrap. In the backwards calculation, the maximum likelihood method is solved by considering three cases corresponding to the involved uncertainties. It is shown that the model can estimate standard deviations for elements so that the real values lie within the estimated 95% confidence interval. Moreover, the results of the model application in each target product show that the estimated scrap composition results in a melt composition, which is in good agreement with the measured one. The model can be applied to increase our understanding of scrap chemical composition and lower the charged material cost and carbon footprint of the products. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 31. Attri, Shubham Dutt
    et al.
    Singh, Shweta
    Dhar, Atul
    Powar, Satvasheel
    Dalarna University, School of Information and Engineering, Energy Technology. Indian Institute of Technology Mandi, Himachal Pradesh, India.
    Multi-attribute sustainability assessment of wastewater treatment technologies using combined fuzzy multi-criteria decision-making techniques2022In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 357, article id 131849Article in journal (Refereed)
    Abstract [en]

    Water, which is predicted to be one of the most critical resources for the near future, also plays a vital role in society's sustainable development. Wastewater treatment is a critical part of the circular water management system and offers various technological alternatives. Taking appropriate decision for the technology selection is, therefore, essential for a long-term perspective. A complex yet imperative process is the sustainable selection of the wastewater treatment process. This paper presents the use of multi-criteria decision-making (MCDM) in the sustainability assessment of wastewater treatment technologies that may be very relevant to the growing sector with many emerging options. A comparison of six wastewater treatment technologies based on four sustainability parameters using three MCDM techniques, namely FSWARA, FMOORA and FTOPSIS is presented in detail. FSWARA is used for weighting criteria and the other two for technology ranking. The detailed step-by-step comparison study is presented and the results were somewhat predictable for the study, and this confirms the reliability of the methodology. This paper's primary objective is to propose a well-defined increscent practice for making sustainable wastewater treatment decisions among state-of-the-art technologies.

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  • 32.
    Backer-Meurke, Henrik
    et al.
    Dalarna University, School of Information and Engineering.
    Polland, Marcus
    Dalarna University, School of Information and Engineering.
    Predicting Road Rut with a Multi-time-series LSTM Model2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Road ruts are depressions or grooves worn into a road. Increases in rut depth are highly undesirable due to the heightened risk of hydroplaning. Accurately predicting increases in road rut depth is important for maintenance planning within the Swedish Transport Administration. At the time of writing this paper, the agency utilizes a linear regression model and is developing a feed-forward neural network for road rut predictions. The aim of the study was to evaluate the possibility of using a Recurrent Neural Network to predict road rut. Through design science research, an artefact in the form of a LSTM model was designed, developed, and evaluated.The dataset consisted of multiple-multivariate short time series where research was limited. Case studies were conducted which inspired the conceptual design of the model. The baseline LSTM model proposed in this paper utilizes the full dataset in combination with time-series individualization through an added index feature. Additional features thought to correlate with rut depth was also studied through multiple training set variations.

    The model was evaluated by calculating the Root Mean Squared Error (RMSE) and the Mean Absolute Error (MAE) for each training set variation. The baseline model predicted rut depth with a MAE of 0.8110 (mm) and a RMSE of 1.124 (mm) outperforming a control set without the added index. The feature with the highest correlation to rut depth was curvature with a MAEof 0.8031 and a RMSE of 1.1093. Initial finding shows that there is a possibility of utilizing an LSTM model trained on multiple-multivariate time series to predict rut depth. Time series individualization through an added index feature yielded better results than control, indicating that it had the desired effect on model performance.

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  • 33. Bai, W.
    et al.
    Johanson, Martin
    Dalarna University, School of Culture and Society, Business Administration and Management. Uppsala University.
    Oliveira, Luis
    Dalarna University, School of Culture and Society, Business Administration and Management. Dalarna University, School of Information and Engineering, Microdata Analysis. Center for International Business Studies, Fundação Getúlio Vargas, Brazil.
    Ratajczak-Mrozek, M.
    Francioni, B.
    Where business networks and institutions meet: Internationalization decision-making under uncertainty2022In: Journal of International Management, ISSN 1075-4253, E-ISSN 1873-0620, Vol. 28, no 1, article id 100904Article in journal (Refereed)
    Abstract [en]

    Both business networks and institutional forces are relevant to firm internationalization but they have seldom been studied together. We investigate under what circumstances firms are more likely to adopt non-predictive strategy in light of the influence of the business networks, the institutional forces, and the home market background affecting their internationalization. Based on survey data from 758 small and medium-sized enterprises (SMEs) from Brazil, China, Poland, Italy, and Sweden, our results support the effects of formal institutional distance and cultural differences on the use of non-predictive strategies by SMEs in internationalization decisions, as well as the contingency effects of business network stability and of having an emerging market background. We integrate research on the liability of foreignness and the liability of outsidership and find that business network stability is critical. It does not moderate the relation between cultural difference and NPS adoption but attenuates the negative relation between institutional distance and NPS adoption, indicating that the liabilities of foreignness and outsidership play different roles in internationalization. © 2021 The Author(s)

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  • 34.
    Bai, Wensong
    et al.
    Dalarna University, School of Culture and Society, Business Administration and Management. Zhejiang University of Technology, Hangzhou, China; Uppsala University.
    Hilmersson, M.
    Johanson, Martin
    Dalarna University, School of Culture and Society, Business Administration and Management. Uppsala University.
    Oliveira, Luis
    Dalarna University, School of Culture and Society, Business Administration and Management. Dalarna University, School of Information and Engineering, Microdata Analysis.
    SMEs' regional diversification: dynamic patterns and home market institutional determinants2023In: International Marketing Review, ISSN 0265-1335, E-ISSN 1758-6763Article in journal (Refereed)
    Abstract [en]

    Purpose: The authors seek to advance the understanding of small- and medium-sized enterprise (SME) internationalization at the regional level and examine the role of home market institutions in this process. Design/methodology/approach: The authors analyze hypotheses with data from SMEs in five country markets and from the Global Entrepreneurship Monitor. A cluster analysis establishes the regional diversification patterns (based on regional diversification scope, speed and rhythm) and a multinomial regression tests the effect of home market institutions on their adoption. Findings: The results offer a refined picture of SME regional diversification by revealing three patterns: intra-regionally focused firms, late inter-region diversifiers and early inter-region diversifiers. They also suggest that the adoption of these patterns is determined by SMEs' home market institutions. Originality/value: The authors develop a nuanced understanding of SME internationalization by building upon and expanding the regionalization rationale in the internationalization patterns literature. Additionally, the authors address the acknowledged, yet rarely investigated, country-level determinants of internationalization patterns. © 2023, Emerald Publishing Limited.

  • 35.
    Bai, Wensong
    et al.
    Dalarna University, School of Culture and Society, Business Administration and Management. Zhejiang University of Technology, China; Uppsala University.
    Johanson, Martin
    Dalarna University, School of Culture and Society, Business Administration and Management. Uppsala University; University of Huddersfield, UK.
    Oliveira, Luis
    Dalarna University, School of Culture and Society, Business Administration and Management. Dalarna University, School of Information and Engineering, Microdata Analysis. Center for International Business Studies, Fundação Getúlio Vargas, Brazil.
    Ratajczak-Mrozek, Milena
    Poznan University.
    The Role of Business and Social Networks in the Effectual Internationalization: Insights from Emerging Market SMEs2021In: Journal of Business Research, ISSN 0148-2963, E-ISSN 1873-7978, Vol. 129, p. 96-109Article in journal (Refereed)
    Abstract [en]

    This study investigates the performance implications of the distinct mechanisms represented by business and social networks in the effectual internationalization. Our hypotheses consider the influence of both network types on firms’ decision-making during internationalization, including the use of effectuation’s overarching principle of non-predictive strategy and the analysis of affordable losses as preferred criterion for selecting between action paths. We test our structural model on a sample of 469 SMEs from Brazil, China, and Poland. The analysis demonstrates that the knowledge circulating in the firms’ business networks negatively moderates the relationship between non-predictive strategy and affordable losses, while social networking mediates the relationships between both non-predictive strategy and affordable losses, on the one hand, and international performance, on the other.

  • 36.
    Barraza, Diego
    Dalarna University, School of Information and Engineering, Information Systems.
    Behov av systemintegration i energibranschen: En fallstudie om hur ett behov uppstår.2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The case study has examined how a need arises to integrate information systems with each other, what it means for companies that do not choose to integrate information systems and what advantages and disadvantages there are with system integration. The case company which in this study is called “Energiföretaget AB” and has several areas of responsibility that are considered to be socially important services for the infrastructure. The company provides locals with energy, drinking water, waste management and heat. Based on the business' seven different areas of responsibility, the case company is forced to use several information systems that provide the business system with all the necessary data for the staff to be able to create and connect with customers. The data collection was carried out via semi-structured interviews and three different people were interviewed from the case company. The selection of respondents is based on various criteria that were considered necessary for the study. The analysis has been able to reflect the study's theories that present four different types of information systems that companies can use and seven different motives for system integrations. The result of the study is that the need for system integration can consist of the outside world's demands on the business, where political decisions also affect whether the information systems must be changed and integrated with other information systems. The case company's latest expansion of area of responsibility also affects information systems in the business to be able to meet the work processes' needs. This means that changes are taking place and existing information systems must be integrated. It answers the first research question in this study. The second research question, which is what it means for companies that do not choose to integrate information systems, has not been answered due to the insufficient data collected and cannot be generalized. The third research question, which are the advantages and disadvantages of system integrations, has been answered and summarized in a table. Based on the analysis, the respondents' answers have been summarized in the table and report several points in both advantages and disadvantages. A recurring point that the respondents mentioned was that manual work disappears and minimizes errors in the information systems.

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  • 37. Barthwal, M.
    et al.
    Dhar, A.
    Powar, Satvasheel
    Dalarna University, School of Information and Engineering, Energy Technology. School of Engineering, Indian Institute of Technology, India.
    Effect of Nanomaterial Inclusion in Phase Change Materials for Improving the Thermal Performance of Heat Storage: A Review2021In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 4, no 8, p. 7462-7480Article in journal (Refereed)
    Abstract [en]

    Dispersion of nanoparticles is one of the potential solutions to improve the thermophysical properties of phase change (or transition) materials (PCMs) and enhance the performance of latent thermal energy storage (LTES) systems. The PCM ought to have a high latent heat of fusion, and zero or negligible coefficient of thermal expansion. A good PCM should have melting and solidification compatibility with negligible or zero subcooling, and it should not react with the common chemical reagents. The present known PCMs possess low thermal conductivity that results into a longer solidification and melting time of PCMs. In the past two decades, researchers have reported improved thermal conductivity and heat-storing capacity of PCMs employing graphite nanoparticles/fibers, carbon nanotubes/fibers, metal, and metal oxide nanoparticles. This work reviews the reported experimental and numerical studies describing the consequences of nanoparticle inclusions of various shapes and sizes on the thermal properties of the PCMs. This review attempts to make a consolidated database of the studies related to nanoadditive inclusion into PCMs for various applications. Graphene dispersed into PCM has resulted into 14 times thermal conductivity enhancement. As far as metal oxide nanoparticles are concerned, TiO2 and Al2O3 nanoparticles outperformed others. The compatibility between the nanoadditive and PCM is necessary to tailor favorable thermal properties. This work reviews numerous studies of different nanoparticle-PCM duos. © 2021 American Chemical Society.

  • 38. Bejjani, Roland
    et al.
    Salame, Charlie
    Olsson, Mikael
    Dalarna University, School of Information and Engineering, Materials Technology.
    An Experimental and Finite Element Approach for a Better Understanding of Ti-6Al-4V Behavior When Machining under Cryogenic Environment2021In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 14, no 11, article id 2796Article in journal (Refereed)
    Abstract [en]

    Due to increasing demand in manufacturing industries, process optimization has become a major area of focus for researchers. This research optimizes the cryogenic machining of aerospace titanium alloy Ti-6Al-4V for industrial applications by studying the effect of varying the nozzle position using two parameters: the nozzle's separation distance from the tool-chip interface and its inclination angle with respect to the tool rake face. A finite element model (FEM) and computational fluid dynamics (CFD) model are used to simulate the cryogenic impingement of cryogenic carbon dioxide on the tool-workpiece geometry. Experiments are conducted to evaluate cutting forces, tool wear, and surface roughness of the workpiece, and the results are related to the CFD and FEM analyses. The nozzle location is shown to have a significant impact on the cutting temperatures and forces, reducing them by up to 45% and 46%, respectively, while the dominant parameter affecting the results is shown to be the separation distance. Cryogenic machining is shown to decrease adhesion-diffusion wear as well as macroscopic brittle chipping of the cutting insert compared to dry turning, while the workpiece surface roughness is found to decrease by 44% in the case of cryogenic machining.

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  • 39.
    Belash, Daniel
    Dalarna University, School of Information and Engineering.
    Hållbar förflyttning: Omvandling av en bilanpassad stad till en gång- och cykelvänlig stad2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Our immediate future faces major challenges that need to be solved to continue our existence. Human impact on the Earth has reached global proportions due to our way of living and exploiting natural resources without much consequence. The human quest to live more comfortably and abundantly has led to urbanization and technological progress that has created resource-consuming tools such as transport. In the last part of modern history, urban planning has taken a new turn and cities have become increasingly adapted to our vehicles, negatively affecting social, economic, and ecological sustainability.

    This thesis aims to use previous research to find solutions that could transform car-adapted cities into more walking and cycling-friendly cities. The work is applied in the city of Borlänge, which is in Dalarna and has been strongly characterized by the development of automobilism. The importance of the work is to highlight solutions that can also be used in other cities regardless of geographical location or size.

    The reviewed literature has created a detailed and comprehensive basis to enable further work with the development of measures that can solve the purpose of the study. The literature has been selected according to relevance to the subject of urban planning to present a similar focus of knowledge, which has made the text more coherent. Most of the literature is scientific articles and books.

    The work has been carried out with the help of a place inventory that helped to discover various characteristics of the existing environment and the selection of two pedestrian and bicycle paths for the development of design proposals. Previous research has provided the basis for the measures presented in the form of design proposals. 

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  • 40.
    Berghauser Pont, Meta
    et al.
    Chalmers tekniska högskola.
    Hannula, Nina
    Göteborgsregionen.
    Isemo, Sanna
    Urban Futures.
    Ranhagen, Ulf
    Dalarna University, School of Information and Engineering, Construction.
    Förtätning av stationsnära områden för god tillgänglighet: Utveckling av en analys- och utvärderingsmetod2022Report (Refereed)
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  • 41.
    Berglund, Gustaf
    et al.
    Dalarna University, School of Information and Engineering.
    Johnsson, Axel
    Dalarna University, School of Information and Engineering.
    Takstolslösningar i garagebyggnader med inredd vind.: Undvika pelare i garageutrymmen2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study focuses on possible roof truss solutions in garages with furnished attics. The text writers, on behalf of AB Karl Hedin whose customers' wishes have sometimes been difficult to achieve. This is because large spans are needed to create as large an area in the attic as possible. Customers also request the garage area to be completely open, namely. Without the carrying aid of, for example, pillars or partitions. There are many ways to erect conceivable rafters for garages with furnished attic, problems are added when the spans become too large. The problems are based on both material use, construction solutions and dimensions. To design a rafter at present time, the construction of construction requirements, loads and calculation models is controlled depending on the desired span of the rafters, as well as the area of use in the attic space. With the help of, among other things, literature study, calculations and analyses, proposals have been discussed on construction parts, materials and development opportunities for the rafters in question. Based on the chosen range, different solutions have been reviewed to achieve the best possible result. The calculations have shown that a collaborative support leg wall is a good method that extends the span up to 2m on a building. Steel carrying line has also proven to be a good construction solution that extends the span of the floor beams. With the chosen dimension of steel beam in this study, the depth of the building must be considered to meet the construction requirements regarding torque force and deflection. The properties of the materials and the intended methods for solving the problem of large spans have since been compared against each other to determine which method is best suited for the intended purpose. The material properties chosen for the comparison are the materials that the roof truss manufacturer currently has access to, which was a limitation for this study.

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  • 42.
    Bergström, Mattias
    Dalarna University, School of Information and Engineering.
    En jämförande livscykelanalys mellan olika material för en fristående bulkvägg: En studie som jämför betong och stål/plåt som material för en fristående vägg ur ett utsläppsperspektiv2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The construction and real estate sector accounts for 21% of domestic greenhouse gas emissions, making it a significant factor in Sweden's efforts to reach its climate goals, with the long-term goal being to have no net emissions to the atmosphere by 2045. By creating a life cycle assessment (LCA), the amount a building contributes to the greenhouse effect throughout its lifespan can be calculated. Hallbyggarna is the leading Nordic provider of tent halls, including bulk halls specifically designed for storing unpackaged materials. This study aims to investigate the environmental impact of a free-standing wall in a bulk hall, comparing the impact of a sheet metal wall to that of a concrete wall in the product stages (A1-A3). To construct the sheet metal wall, a simulation of the horizontal forces the bulk material will exert on the wall was required. One Click LCA was the software used in this study. When creating a life cycle inventory (LCI), an environmental product declaration (EPD) or generic data (average data) is selected, followed by the product quantities in One Click LCA. Once the LCI is complete, an impact assessment (LCIA) can be conducted and analyzed. The study revealed that a concrete structure of this size emits 103 tons of CO2e, while a sheet metal wall construction with 0% recycled steel in the frame emits 60 tons of CO2e. A comparison was made using a steel frame containing 100% recycled steel in the sheet metal wall construction, resulting in a 12% reduction in CO2e emissions compared to the sheet metal wall construction with 0% recycled steel.

  • 43.
    Bhagat, Rohit Jayprakash
    Dalarna University, School of Information and Engineering.
    Investigation of different factors’impacts on the Peer-to-Peer solarpower sharing potential2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Recent years the world has witnessed solar energy gaining popularity, as everyone is inpursuit of a more sustainable form of energy. However, the transition to solar energy hasbeen slow, short term oriented and consumers fail to see the long-term advantages ofswitching to green solutions. Peer-to-peer (P2P) energy sharing solutions are expected tobe the future of solar sector. It is ingenious as it enables cheaper and more efficient powersharing within the community at all hours of the day.The thesis aimed to investigate the impacts of different factors on the P2P solar powersharing performances, including the climate conditions (locations), Photovoltaic (PV)capacity ratio, and energy storage integration. In order to study the impact of differentclimate conditions on energy sharing, three locations are selected, namely, Sweden(Stockholm), Italy (Rome), and India (Bengaluru). For studying the impacts of PV capacityratios and energy storage integration on the power sharing performances, theperformances under a set of different PV capacity ratios and energy storage capacities arestudied.Five basic steps are followed in order to perform the above-mentioned studies. First, theconfiguration of the design alternatives is properly selected, and a 3D model is developedin a format that can be imported into a simulation software. Second, the electricity load iscalculated for a group of single-family houses and apartment buildings considering theelectricity devices such as lighting, cooking, refrigerator, washer, dryer etc. Similarly, forcommercial buildings, electricity load is calculated by considering daily energy demand forservers, computers, and lighting. Third, the simulation software is used to perform theestimation of renewable energy production. The simulation software requires inputs suchas PV area, surrounding area, weather data file and load profile. The output is the hourlyPV production and economic analysis. The fourth step is to evaluate the potential forpower-sharing in different communities by using the obtained building electricity load andpower supply data. The impacts of different factors are analysed and discussed in the laststep of this study. The result is in the form of how much amount of power can be sharedin the community considering the various factors mentioned above.The result of the study shows that more power can be shared if a community has a higherpercentage of PV. A small percentage of PV is unable to achieve the maximum amount ofpower sharing. In the case of energy storage, with the increase of battery capacity, powersharing will increase and gradually reach a saturation point. After the saturation point, theincrease in battery storage will not lead to any rise in power sharing. Summarizing thescientific contribution of this study can help urban designers or engineers to design or planpower sharing building community in the future. Also, empowers prosumers andconsumers, leading to increased renewable energy deployment and flexibility in the grid.

  • 44.
    Bhat, Adhyapadi Apoorva
    et al.
    Dalarna University, School of Information and Engineering, Microdata Analysis.
    Koothenparambil Joy, Jomin
    Dalarna University, School of Information and Engineering, Microdata Analysis.
    Fault Detection in PV System using Machine Learning Technique2023Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With the steady and rapid reliance on solar power as a viable alternative to traditional fuel-based energy, maintenance of solar panels is becoming an unavoidable issue for both producers and consumers. Machine learning techniques are useful in detecting solar panel faults and their life span. In recent years, Machine learning technology has emerged that helps to extract meaningful information and detect the fault in PV Systems. This paper reviews and involves identifying faulty features and predicting the fault in residential PV Systems that causes power degradation. We have built a linear regression model and performed hierarchical clustering to identify the faulty group of data, and from that faulty group, we identified that the features such as Radiation, Module Temperature, and IS values play an important role in the degradation of the power generation in the solar panels. Additionally, in this study fault prediction in a PV system has also been attempted. We evaluated the performance using 6 different models SVM, KNN, Naive Bayes Random Forest, Decision Tree and Logistic Regression. Finally, we concluded that the Random Forest, KNN and Decision Tree performed better in predicting with an accuracy of 99 %.

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  • 45.
    Bjurell, Lovisa
    et al.
    Dalarna University, School of Information and Engineering.
    Svensson, Joel
    Dalarna University, School of Information and Engineering.
    Potential för solcellsanläggningar: SSAB industriområde, Borlänge2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    SSAB's goal by year 2026 is to produce fossil-free steel and be completely fossil-free by 2030. One step to succeed in this is to generate their own renewable energy. In this work, the authors investigated the potential for generating renewable energy in the form of solar electricity at SSAB’s industrial area in Borlänge. This study also provides suggestions on which solar cell technology can be utilized, as well as how the power from the photovoltaic plants affects SSAB's two largest transformers. The base load of these transformers can mostly be achieved by the photovoltaic plants between April – August.

    The boundaries made aim to investigate the potential of the largest areas in the form of land and on buildings of the industrial area. Simulations have been carried out with the software PVsyst for several photovoltaic systems. This work highlights aspects of how photovoltaic systems work, how they are planned and affected by, for example, solar radiation, weather and orientation. The simulated photovoltaic systems have different conditions based on the different aspects, where each one has their pros and cons.

    The result shows that on the surfaces that were selected, a maximum power of 28 MWp can be installed. Most of the total power can be installed on the available land surfaces, which corresponds to about 70 % of the simulated installation. As the available areas are directed in different directions, the proposed installations will have their maximum output at different times, so the maximum output from all plants never exceeds 22 MW. The total amount of electricity that can be generated from all installations is 23.7 GWh / year. This amount of energy corresponds to about 6% of SSAB in Borlänge's total electricity use. With monocrystalline solar cells, a cost for all installations amounts to SEK 164 million ± 20%.

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  • 46.
    Björklund, Alice
    Dalarna University, School of Information and Engineering.
    Barnkonsekvensanalys som verktyg för samhällsplanering: En fallstudie om kommunal planering av skolvägar i Borlänge och Falun2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The increase in the number of cars that has taken place from the mid-1950s to the beginning of the 2000s has developed into a major societal problem that affects the perceived security among many children and their guardians. Many guardians experience that the school area and the road between home and school is insecure. For that reason, many parents choose to transport their children to and from school by car, which affects the children who are still walking, or cycling as they are exposed to even greater risk. The free choice of school in combination with the establishment of independent schools has further aggravated the situation as the children get a longer way to school when the parents are free to choose a school. When the children are no longer placed in the nearest school, it becomes difficult for the municipalities to predict which roads will be used as school roads. As a result, many school roads are not designed with the children in focus, which would have been favorable. In this study, a case study was conducted on two medium-sized municipalities in Dalarna with the aim of investigating how they work with planning school routes and whether child impact assessment is a tool used to ensure the best interests of children. The results may indicate that there is a gap between theory and practice as none of the municipalities carry out child impact assessments. One of the municipalities also tells that they have no routine for conducting dialogues with children and young people even though there is now a statutory requirement that children should be given the opportunity to express their opinion on all issues concerning them, according to the Convention on the Rights of the Child. A survey has been conducted to examine what guardians of children in middle school think about the traffic safety along their children's school roads and how their children travel to and from school. It turns out that most of the children in grades 4-6 in the selected schools walk or cycle to and from school on their own. The survey indicates that 12% of the children in Borlänge and 16% of the children in Falun are transported to school. Most guardians considerit is practical or convenience that the children are transported by car. 

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  • 47.
    Björklund, Alice
    Dalarna University, School of Information and Engineering, Civil planning and Construction.
    Barnkonsekvensanalys som verktyg för samhällsplanering: En fallstudie om kommunal planering av skolvägar i Borlänge och Falun2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The increase in the number of cars that has taken place from the mid-1950s to the beginning of the 2000s has developed into a major societal problem that affects the perceived security among many children and their guardians. Many guardians experience that the school area and the road between home and school is insecure. For that reason, many parents choose to transport their children to and from school by car, which affects the children who are still walking, or cycling as they are exposed to even greater risk. The free choice of school in combination with the establishment of independent schools has further aggravated the situation as the children get a longer way to school when the parents are free to choose a school. When the children are no longer placed in the nearest school, it becomes difficult for the municipalities to predict which roads will be used as school roads. As a result, many school roads are not designed with the children in focus, which would have been favorable. In this study, a case study was conducted on two medium-sized municipalities in Dalarna with the aim of investigating how they work with planning school routes and whether child impact assessment is a tool used to ensure the best interests of children. The results may indicate that there is a gap between theory and practice as none of the municipalities carry out child impact assessments. One of the municipalities also tells that they have no routine for conducting dialogues with children and young people even though there is now a statutory requirement that children should be given the opportunity to express their opinion on all issues concerning them, according to the Convention on the Rights of the Child. A survey has been conducted to examine what guardians of children in middle school think about the traffic safety along their children's school roads and how their children travel to and from school. It turns out that most of the children in grades 4-6 in the selected schools walk or cycle to and from school on their own. The survey indicates that 12% of the children in Borlänge and 16% of the children in Falun are transported to school. Most guardians consider it is practical or convenience that the children are transported by car.

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  • 48.
    Björklund, Maria
    Dalarna University, School of Information and Engineering.
    Simulation Tool for Design of Multiple Photovoltaic Systems: Estimation of System Sizes, Grid Interaction, and Area Requirements2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Photovoltaic solar power is an increasing source of energy and part of the renewable energy generation which is needed in the near future to achieve the set climate goals. When planning new photovoltaic installations, parameters which affect the design are both local conditions (e.g. weather) and system parameters such as tilt and azimuth angles. Commercial areas often have high loads during the day when solar power is available and are therefore interesting for photovoltaic installations. In order make a quick estimation of photovoltaic power potential in an area, a simulation tool which handles load profiles from multiple buildings would be desirable. The aim of this thesis project is therefore to create a tool which can simulate multiple photovoltaic systems and for each of them estimate system sizes, grid interactions, and area requirements. The simulation tool is based on Python programming with the aid of System Advisor Model, a simulation software for photovoltaic and other renewable energy tech-nologies. Optimization of orientation angles was made for clear sky with the goal of high load-generation match. Different system sizes were estimated and simulated based on different degrees of self-sufficiency, net-zero consumption, and the existing transfer capacity of the building in question. When the simulation result was compared to a detailed photovoltaic design project, some agreements between the results were found, as well as further development needs such as refining area estimation. To further develop the usability of the tool, a more user-friendly interface is needed. Other improvements could be to enable simulations of multiple direction systems and integration of the local grid structure and limitations.

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  • 49.
    Björkstrand, Victoria
    et al.
    Dalarna University, School of Information and Engineering.
    Leidevall, Malin
    Dalarna University, School of Information and Engineering.
    Ökat återbruk av byggmaterial genom digital publicering: En inblick i Dala återbyggdepå2022Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Borlänge kommun har infört miljömål som handlar om samhällets styrning för att den byggda miljön ska användas, utvecklas och bevaras på ett hållbart sätt. För att uppnå ett miljösmart och långsiktigt byggande behöver återbrukandet av byggmaterial öka och för att främja detta grundades Dala återbyggdepå av ett anta laktörer i Borlänge kommun. Depån fungerar som en fysisk butik med återbrukat material som har lämnats in av företag eller privatpersoner. Kundkretsen består idag mestadels av privatpersoner men syftet med denna studie har varit att undersöka hur efterfrågan från aktörer i byggbranschen på återbrukat byggmaterial kan öka och om digital publicering av produkter kan vara en väg till det. För att ta reda på detta gjordes studiebesök på Dala återbyggdepå och litteraturstudier på ämnet. Intervjuer gjordes med en beställare och en entreprenö som verkar i kommunen för att få deras perspektiv på vad som skulle krävas. Studien har visat att det är nödvändigt för Dala återbyggdepå att ta ett steg mot digital försäljning för att öka efterfrågan och ett förslag till materialhanteringsrutin har arbetats fram. Sammanfattningsvis har studien även visat att det finns fler utmaningar för användandet av återbrukat material i byggbranschen. Med dagens krav på dokumentation blir det svårt att uppnå godkänd nivå mot miljömål och beställare behöver ange redan i handlingarna att återbrukat byggmaterial ska användas. Slutligen kan det krävas en ändrad inställning från branschen som ger återbrukat material högre status och att företag värderar den miljömässiga vinningen högre för att fler ska vilja, våga och kunna bygga hållbart med återbrukat material.

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  • 50.
    Björs, Linus
    Dalarna University, School of Information and Engineering.
    Konceptutveckling av joystick2022Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Åkerströms Björbo AB is an international company founded in 1918 in Björbo, Central Sweden, offering a holistic concept within communications and radio control for industrial and mobile applications. The company develops, produces, markets and services its products and services. Over time, products have been created and used in the product offering but have not been kept up to date. Sometime in the 80s, a joystick is created that is implemented on the product catalog. The joystick has been included in the product catalog since then and has been modified as needed to satisfy more and more customer requirements.

    The purpose of this thesis is to begin the creation of a joystick that on other company can produce and deliver. To fulfil and combine Åkerström's customers' requirements and wishes on a joystick that on one else can deliver. And to meet these requirements and wished as resource efficient as possible.

    The goal of an improved design of the joystick is to produce one or more concepts with basis for what is to be reviewed and what needs to be further developed. The joystick should be developed with the user and their customer requirements in mind. Åkerströms should be able to continue and further develop the joystick with the results and data that will be produced by this thesis.

    In order to obtain qualitive data, meetings with staff have been used and furthermore questionnaires have been used to be filled in my relevant staff. Information has also been obtained by analyzing internal company documents, as well as Åkerströms and competitors joysticks.

    The product's various functions have been investigated, focus was placed on the functions reading axial motion and indication functions. The development of the joystick is done with optimization and efficiency in mind.

    The analysis of the joystick was performed without considering the electrical and ergonomic components. No account was taken of the physical constraints on the waist transmitter in which the joystick is to be mounted.

    Concepts have been developed for reading axial motion and indication functions. The methods that have been used are quality function deployment, concept screening and scoring and design for assembly.

    Finally, the concepts have been evaluated, analyzed, combined and compiled to arrive at a winning concept. This concept should be the most suitable option based on the information obtained.

    The result of the thesis work is a winning concept for further development. This concept is the result of the product development methods chosen.

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