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  • 1.
    Abd Alrahman, Chadi
    Dalarna University, School of Technology and Business Studies, Electrical Engineering.
    Evaluation of a PVT Air Collector2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Hybrid Photovoltaic Thermal (PVT) collectors are an emerging technology that

    combines PV and solar thermal systems in a single solar collector producing heat and

    electricity simultaneously. The focus of this thesis work is to evaluate the performance of

    unglazed open loop PVT air system integrated on a garage roof in Borlänge. As it is

    thought to have a significant potential for preheating ventilation of the building and

    improving the PV modules electrical efficiency. The performance evaluation is important

    to optimize the cooling strategy of the collector in order to enhance its electrical efficiency

    and maximize the production of thermal energy. The evaluation process involves

    monitoring the electrical and thermal energies for a certain period of time and investigating

    the cooling effect on the performance through controlling the air mass flow provided by a

    variable speed fan connected to the collector by an air distribution duct. The distribution

    duct transfers the heated outlet air from the collector to inside the building.

    The PVT air collector consists of 34 Solibro CIGS type PV modules (115 Wp for each

    module) which are roof integrated and have replaced the traditional roof material. The

    collector is oriented toward the south-west with a tilt of 29 ᵒ. The collector consists of 17

    parallel air ducts formed between the PV modules and the insulated roof surface. Each air

    duct has a depth of 0.05 m, length of 2.38 m and width of 2.38 m. The air ducts are

    connected to each other through holes. The monitoring system is based on using T-type

    thermocouples to measure the relevant temperatures, air sensor to measure the air mass

    flow. These parameters are needed to calculate the thermal energy. The monitoring system

    contains also voltage dividers to measure the PV modules voltage and shunt resistance to

    measure the PV current, and AC energy meters which are needed to calculate the

    produced electrical energy. All signals recorded from the thermocouples, voltage dividers

    and shunt resistances are connected to data loggers. The strategy of cooling in this work

    was based on switching the fan on, only when the difference between the air duct

    temperature (under the middle of top of PV column) and the room temperature becomes

    higher than 5 °C. This strategy was effective in term of avoiding high electrical

    consumption by the fan, and it is recommended for further development. The temperature

    difference of 5 °C is the minimum value to compensate the heat losses in the collecting

    duct and distribution duct.

    The PVT air collector has an area of (Ac=32 m2), and air mass flow of 0.002 kg/s m2.

    The nominal output power of the collector is 4 kWppv (34 CIGS modules with 115

    Wppvfor each module). The collector produces thermal output energy of 6.88 kWth/day

    (0.21 kWth/m2 day) and an electrical output energy of 13.46 kWhel/day (0.42 kWhel/m2

    day) with cooling case. The PVT air collector has a daily thermal energy yield of 1.72

    kWhth/kWppv, and a daily PV electrical energy yield of 3.36 kWhel /kWppv. The fan energy

    requirement in this case was 0.18 kWh/day which is very small compared to the electrical

    energy generated by the PV collector. The obtained thermal efficiency was 8 % which is

    small compared to the results reported in literature for PVT air collectors. The small

    thermal efficiency was due to small operating air mass flow. Therefore, the study suggests

    increasing the air mass flow by a factor of 25. The electrical efficiency was fluctuating

    around 14 %, which is higher than the theoretical efficiency of the PV modules, and this

    discrepancy was due to the poor method of recording the solar irradiance in the location.

    Due to shading effect, it was better to use more than one pyranometer.

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  • 2.
    Abdel Rahman, Assem
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Electrical Evaluation of a Low Concentrating PVT Collector Based on Performance Ratio2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Photovoltaic Thermal/Hybrid collectors are an emerging technology that combines PV

    and solar thermal collectors by producing heat and electricity simultaneously. In this paper,

    the electrical performance evaluation of a low concentrating PVT collector was done

    through two testing parts: power comparison and performance ratio testing. For the

    performance ratio testing, it is required to identify and measure the factors affecting the

    performance ratio on a low concentrating PVT collector. Factors such as PV cell

    configuration, collector acceptance angle, flow rate, tracking the sun, temperature

    dependence and diffuse to irradiance ratio.

    Solarus low concentrating PVT collector V12 was tested at Dalarna University in Sweden

    using the electrical equipment at the solar laboratory. The PV testing has showed

    differences between the two receivers. Back2 was producing 1.8 energy output more than

    Back1 throughout the day. Front1 and Front2 were almost the same output performance.

    Performance tests showed that the cell configuration for Receiver2 with cells grouping (6-

    32-32-6) has proved to have a better performance ratio when to it comes to minimizing

    the shading effect leading to more output power throughout the day because of lowering

    the mismatch losses. Different factors were measured and presented in this thesis in

    chapter 5.

    With the current design, it has been obtained a peak power at STC of 107W per receiver.

    The solar cells have an electrical efficiency of approximately 19% while the maximum

    measured electrical efficiency for the collector was approximately 18 % per active cell area,

    in addition to a temperature coefficient of -0.53%/ ˚C. Finally a recommendation was

    done to help Solarus AB to know how much the electrical performance is affected during

    variable ambient condition and be able to use the results for analyzing and introducing

    new modification if needed.

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  • 3.
    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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  • 4.
    Abdi, Faisa
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Farah, Muse
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Energieffektivisering av Limatvätten AB: Värmeåtervinning från manglar2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy efficiency is in the interest of all industries, as it involves the reduction of both energy and cost. The purpose of this project for a bachelor’s degree is to analyse potential energy recovery of waste heat from an ironer.

    The work was carried out at Limatvätten AB, which is a large and modern laundry facility. Limatvätten AB is a textile service company that has been in existence for 50 years. The Lima laundry’s main customers are from the hotel and restaurant business. Limatvätten AB has its own textiles that are rented to hotels, conferences, etc. The largest customers are in Sälenfjällen and in the Siljan region.

    The work is done by identifying moisture, temperature and dynamic pressure in an ironer Based on measurements, the amount of energy that can be recycled is calculated. Heat recovery system proposals are also given in the report. Aquavent is a heat exchanger that uses ventilation heat from the ironers. The water that is heated in the aquavent is led into the washing pipes, which leads to the reduction of steam consumption in washing processes. Temperature change depends on the heat exchanger's efficiency, the higher the temperature change, the more amount of energy recovery is obtained.

    After identification of the problem, a timetable was mapped, and appropriate instruments and interesting parameters were chosen. The moisture content, temperature and dynamic pressure have been measured. The equations described in the theory section are used for most of the calculations with the help of Excel.

    According to the result, the energy saving will be 184 MWh/year if all excess heat from a mangle is reused. Based on the result, the total savings potential is SEK 57 000 /year. According to the results, it is shown that there is the potential to use excess heat from the Lima wash ironers. In addition to the saving of energy, climate impact is also reduced, as the excess energy is again reused which would otherwise disappear into the atmosphere. If two of the ironers are coupled with a heat recovery system, it results in a doubling on the savings potential.

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  • 5.
    Abdi Mohammed, Farhan
    et al.
    Dalarna University, School of Technology and Business Studies, Construction.
    A Said, Mahdi
    Dalarna University, School of Technology and Business Studies, Construction.
    Möjligheten att utföra LCA i en totalentreprenad: En studie om LCA i en totalentreprenad2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The environment is an important issue in society today. Emissions contribute to medium temperature rises gradually allowing the consequences on the nature, climate and society. The construction industry accounts for approximately 40 % of all energy use in Sweden. The environment in various ways, namely that different lifestyles and ways of life such as heating residences, waste management, travel to and from work affects the adverse impact on the environment. With the help of the growing awareness of the environment and the impetus given to it by the public authorities to reduces the environmental impact and energy use. LCA is a systematic analysis that is new in the construction industry where construction processes measured by the flow of energy and material usage. LCA can help decision makers by performing the LCA can be developed in analytical evaluations environmentally. Without LCA would investment, costs may be the most important thing for the decision makers than the environmental benefits. The aim of this work is to perform a life cycle assessment in the construction process with total construction and following questions is: • Possibilities to perform LCA in this construction form? • What demands are made from the client? • Possibilities and difficulties with total construction to perform LCA? The aim of this thesis is to illustrate how a life cycle analysis can be performed in a total construction. The study will highlight the role of the client. The focus will be on project Kungsljuset in Borlänge. The method of accounting analysis of the life cycle of the construction project is used and performed in a total construction. Interviews with the project management for this object. The result was unfortunately that there was a lack of data for the implement of LCA in this project. The reason was the knowledge and interest of the lack of both the client and the material supplier. It is required that the client demands on the material supplier and entrepreneur to specify the material and other resources used in this construction project.

  • 6.
    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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  • 7.
    Abrahamsson, Jonas
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Lindqvist, Jakob
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Nedsmutsade värmesystems påverkan på energisystemet: Effektivisering vid användning av rengöringsmetoder2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Contamination of the heating system is not a well-known problem that can have major economic consequences. Due to minerals and low pH in the system arises limescale and corrosion that can clog the system and can damage components. This will result in increased energy consumption for users and a higher energy input from the district heating company. The purpose of this work is to study different cleaning methods for heating systems and if it is viable with cleaning of heating systems. The cleaning effect on the district heating demand and how it affects greenhouse gas emissions and primary energy use. And examine whether the maintenance of the heating system provides less energy than remodeling the building envelope. Previous studies in this area were examined and relevant data were collected after talks with interesting companies working with cleaning of heating systems. Cleaning the heating system was compared with various packages such as remodeling of the building envelope and heat recovery ventilation. Cleaning the heating systems with an efficiency of 10 % resulting in a reduced heating need at 1,63 GWh per year and a reduction in emissions of 177 tonnes CO2e per year. The reduced heating demand resulted in a reduction in primary energy consumption by 113 750 kWh per year. Installation of the cleaning systems can result in a saving for Tunabyggen of 759 200 SEK per year. The conclusion of this work is that the cleaning prolongs the lifetime of heating systems, but can’t replace remodeling of the building envelope in terms of reduced energy consumption.

  • 8.
    Abrahamsson, Lena
    et al.
    Luleå tekniska universitet, Arbetsvetenskap.
    Enander, Mats
    Olsson, Hans
    Luleå tekniska universitet.
    Ranhagen, Ulf
    Luleå tekniska universitet, Arkitektur och vatten.
    Fallstudierapport: Iggesunds bruk. Efterbehandlingen. Arbetsrapport1993Report (Other academic)
  • 9.
    Abrahamsson, Lena
    et al.
    Luleå tekniska universitet, Arbetsvetenskap.
    Enander, Mats
    Luleå tekniska universitet.
    Olsson, Hans
    Luleå tekniska universitet.
    Ranhagen, Ulf
    Luleå tekniska universitet, Arkitektur och vatten.
    Förstudie av massabalshanteringen vid Iggesunds kartongbruk: arbetsrapport1996Report (Other academic)
  • 10.
    Abramowska, Magdalena
    et al.
    Dalarna University, School of Technology and Business Studies, Graphic Arts Technology.
    Ehnlund, Isabell
    Dalarna University, School of Technology and Business Studies, Graphic Arts Technology.
    Snowboardens bildspråk 1980-2010: En kartläggning2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Snowboarding is today a major winter sport with its own equipment, its own culture and elite riders. For professional athletes or for those who just snowboard for fun, snowboard becomes an extension of their body while in motion.

    The layout on the boards has changed over the years but despite of this there is a lack of scientific studies in the field. Therefore, this study aimed to identify how the graphics of 240 snowboards have evolved between 1980-2010, and fill some of these holes in the scientific documentation. 

    This survey was based on a visual content analysis, which resulted in interesting observations. The results that emerged were that the result can be generalized and that the development of snowboards graphics has changed over the decades. Snowboards from the various decades have specific characteristics that this study provides.

  • 11.
    Abreu Saraiva Freitas, Iuri
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Indoor climate: A comparison of residential units in Tjärna Ängar, Borlänge before and after retrofitting2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study try to understand which aspects were fundamental to indoor climate and how to obtain them in order to provide the best possible experience in the thermal comfort of individuals. Thus, arose the studies of Fanger, which was the seed for a new era of discoveries in the area and founded the knowledge our society have today in this globally used standards and norms. Referring to these fundamental aspects of the indoor comfort, data collection was taken in situ to show in details what was happening. This study was executed in order to demonstrate the differences between the data previous and after a process of retrofitting in dwellings built in the 60s and 70s of the century past, in the district of Tjärna Ängar, Borlänge, Sweden. The comparative results using criteria such as Predicted Mean Vote (PMV), Predicted Percentage Dissatisfied (PPD), Draft Rate (DR), air velocity, Mean Radiant Temperature (MRT), Relative Humidity (RH) and air temperature, showed an improvement in 6 of the 8 parameters analyzed. Confirming the expectation that through the retrofitting the residents will be more satisfied, obtain better quality of indoor climate comfort and also increase occupied area in these dwellings.

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  • 12.
    Ackeby, Susanne
    et al.
    STRI AB.
    Tjäder, Jonas
    Bastholm, Caroline
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    The role and interaction of microgrids and centralized grids in developing modern power systems2017Conference paper (Refereed)
    Abstract [en]

    An extension of microgrids is now underway, primarily to allow increased electrification in growing economies but also to meet the need to reduce global CO2 emissions and to provide ancillary services to centralized grids. Energy access constitutes one of the fundamental building blocks for economic growth as well as social equity in the modern world. Access to sustainable energy is needed to achieve sustainable development. A microgrid should not be seen as a competitor to the centralized grid but as a complement.Through examination of several implemented cases from different parts of the world the following topics are considered: Analysis of the interaction between centralized grids and microgrids Analysis of stakeholder decision parameters for electrification Analysis of design differences and requirements for microgrids, depending on the intended purpose and the need of the end customer.It is determined that good planning, suitable requirements and clear regulations for microgrids (in relation to centralized grids) limits the risk of stranded assets and enables better business cases for the involved stakeholders.The paper is based on the discussion paper The role and interaction of microgrids and centralized grids in developing modern power systems – A case review publiced by ISGAN (International Smart Grid Action Network) Annex 6: Power T&D Systems.The discussion paper and further information about ISGAN is available at http://www.iea-isgan.org/.

  • 13.
    Ackemo, Sandra
    Dalarna University, School of Technology and Business Studies, Construction.
    Hästanpassade vägar: I Leksands Kommun2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Approximately 13 000 persons get injured every year in Sweden while riding or handling a horse. Due to regulations, a horse is not allowed on to the walk- and cycle path or the sidewalks. Since some places don’t have paths developed for the horse, the equipage is forced out in trafficked roads. The horse is a prey animal, they run first and then they stop to see what the potential threat was. This, in combination with car driver´s general lack of knowledge about horses, could increase the possibility of an accident.The purpose of this project is to evaluate if the equestrian practitioners find it difficult to be in traffic environment with the horse and how commonly practitioners use public roads with the horse. The purpose is also to provide a review of how well the equestrian practitioners are aware of the traffic rules regarding horses in traffic. The main purpose of this thesis is, however, to offer suggestions on how road design should be improved with regard to road safety, security and accessibility for equestrian practitioners.

    The study was carried out with a questionnaire and studying literature. The questionnaire was handed out to 38 members of the riding club of Leksand. The results show that the knowledge of traffic rules could be increased among the ones who answered the questionnaire. They also think that the horse needs to be a part of the community and infrastructure planning and that all road-users need to learn more about horses in traffic, to better understand its behavior. Other proposals are lowered speed limits for motorized traffic at

  • 14.
    Adegoke, Olutayo
    Dalarna University, School of Technology and Business Studies, Material Science.
    Homogenization of Precipitation Hardening Nickel Based Superalloys2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Allvac 718 Plus and Haynes 282 are relatively new precipitation hardening nickel based superalloys with good high temperature mechanical properties. In addition, the weldability of these superalloys enhances easy fabrication. The combination of high temperature capabilities and superior weldability is unmatched by other precipitation hardening superalloys and linked to the amount of the γ’ hardening precipitates in the materials. Hence, it is these properties that make Allvac 718 Plus and Haynes 282 desirable in the manufacture of hot sections of aero engine components.

    Studies show that cast products are less weldable than wrought products. Segregation of elements in the cast results in inhomogeneous composition which consequently diminishes weldability. Segregation during solidification of the cast products results in dendritic microstructure with the segregating elements occupying interdendritic regions. These segregating elements are trapped in secondary phases present alongside γ matrix. Studies show that in Allvac 718Plus, the segregating phase is Laves while in Haynes 282 the segregating phase is not yet fully determined.

    Thus, the present study investigated the effects of homogenization heat treatments in eliminating segregation in cast Allvac 718 Plus and Haynes 282. Paramount to the study was the effect of different homogenization temperatures and dwell time in the removal of the segregating phases. Experimental methods used to both qualify and quantify the segregating phases included SEM, EDX analysis, manual point count and macro Vickers hardness tests.

    Main results show that there is a reduction in the segregating phases in both materials as homogenization proceeds hence a disappearance of the dendritic structure. In Allvac 718 Plus, plate like structures is observed to be closely associated with the Laves phase at low temperatures and dwell times. In addition, Nb is found to be segregating in the interdendritic areas. The expected trend of increase in Laves as a result of the dissolution of the plate like structures at the initial stage of homogenization is only detectable for few cases. In Haynes 282, white and grey phases are clearly distinguished and Mo is observed to be segregating in interdendritic areas.

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  • 15.
    Adolfsson, Julia
    Dalarna University, School of Technology and Business Studies, Civil planning and Construction.
    Strukturplan: Ett verktyg för att planera den framtida fysiska strukturen?2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetet handlar om ett planeringsverktyg i samhällsplaneringen som har benämningen strukturplan. Syftet med arbetet är att undersöka strukturplaners innehåll och om det är ett användbart planeringsverktyg till efterföljande planering som ingår i den formella planeringsprocessen enligt plan- och bygglagen. Även att undersöka varför kommuner väljer att göra en strukturplan som anses vara en informell plansort, istället för att använda de verktyg som plan- och bygglagen erbjuder. Samt undersöka om tidigare forskning stämmer att kommuner använder strukturplaner för att undvika plan- och bygglagsprocessen.

    Arbetets forskningsdesign är fallstudie med en komparativ analys, fallen som valt är; Utvecklad strukturplan för Nacka stad, Strukturplan Storvreten, Strukturplan Forsåker, samt Strukturplan för Lina.

    Metoderna som använts i arbetet är kvalitativ innehållsanalys och semistrukturerade intervjuer.

    Resultatet av innehållsanalysen visar att en strukturplan är ett dokument som på ett övergripande sätt visar den tänkta fysiska grovstrukturen för ett visst geografiskt område i kommunen inom några år. Strukturplanen innehåller kartor, text och bilder som främst visar framtida markanvändningen, befintliga- och framtida bostäder, grönstruktur och trafikstruktur. Den kan även innehålla andra kartor, exempelvis etappindelning och våningsantal, som kommunen tycker är väsentliga att ha med.

    I de semistrukturerade intervjuerna svarade intressenterna att strukturplanen är ett användbart planeringsverktyg till efterföljande planering och används istället för en fördjupning av översiktsplanen för att undvika plan- och bygglagens formella process. Vilket resulterar i att det stämmer överens med den tidigare utredningen En effektivare plan- och byggprocess (SOU 2013:34), ), att kommuner tar fram en strukturplan för att undvika PBL-processen.

    Slutsatsen är att kommuner väljer att göra en strukturplan som lyfter planeringsfrågor och löser planeringsproblem på en övergripande nivå och ska främst användas som ett internt strategisk planeringsverktyg. En strukturplan skapas för att det finns ett högt krav på att publicera bostäder från politikerna och för att den kommunala planeringsprocessen är tidskrävande. Därför väljer kommunen att frångå arbetet med PBL, och gör istället en strukturplan som planeringsverktyg för tidsbesparing och behöver inte genomföra PBLprocessens formella delar.

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  • 16.
    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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  • 17.
    Aghanavesi, Somayeh
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Sensor-based knowledge- and data-driven methods: A case of Parkinson’s disease motor symptoms quantification2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aim of this thesis was to develop and evaluate new knowledge- and data-driven methods for supporting treatment and providing information for better assessment of Parkinson’s disease (PD).

    PD is complex and progressive. There is a large amount of inter- and intravariability in motor symptoms of patients with PD (PwPD). The current evaluation of motor symptoms that are done at clinics by using clinical rating scales is limited and provides only part of the health status of PwPD. An accurate and clinically approved assessment of PD is required using frequent evaluation of symptoms.

    To investigate the problem areas, the thesis adopted the microdata analysis approach including the stages of data collection, data processing, data analysis, and data interpretation. Sensor systems including smartphone and tri-axial motion sensors were used to collect data from advanced PwPD experimenting with repeated tests during a day. The experiments were rated by clinical experts. The data from sensors and the clinical evaluations were processed and used in subsequent analysis.

    The first three papers in this thesis report the results from the investigation, verification, and development of knowledge- and data-driven methods for quantifying the dexterity in PD. The smartphone-based data collected from spiral drawing and alternate tapping tests were used for the analysis. The results from the development of a smartphone-based data-driven method can be used for measuring treatment-related changes in PwPD. Results from investigation and verification of an approximate entropy-based method showed good responsiveness and test-retest reliability indicating that this method is useful in measuring upper limb temporal irregularity.

    The next two papers, report the results from the investigation and development of motion sensor-based knowledge- and data-driven methods for quantification of the motor states in PD. The motion data were collected from experiments such as leg agility, walking, and rapid alternating movements of hands. High convergence validity resulted from using motion sensors during leg agility tests. The results of the fusion of sensor data gathered during multiple motor tests were promising and led to valid, reliable and responsive objective measures of PD motor symptoms.

    Results in the last paper investigating the feasibility of using the Dynamic Time-Warping method for assessment of PD motor states showed it is feasible to use this method for extracting features to be used in automatic scoring of PD motor states.

    The findings from the knowledge- and data-driven methodology in this thesis can be used in the development of systems for follow up of the effects of treatment and individualized treatments in PD.

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  • 18.
    Aghanavesi, Somayeh
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Smartphone-based Parkinson’s disease symptom assessment2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis consists of four research papers presenting a microdata analysis approach to assess and evaluate the Parkinson’s disease (PD) motor symptoms using smartphone-based systems. PD is a progressive neurological disorder that is characterized by motor symptoms. It is a complex disease that requires continuous monitoring and multidimensional symptom analysis. Both patients’ perception regarding common symptom and their motor function need to be related to the repeated and time-stamped assessment; with this, the full extent of patient’s condition could be revealed. The smartphone enables and facilitates the remote, long-term and repeated assessment of PD symptoms. Two types of collected data from smartphone were used, one during a three year, and another during one-day clinical study. The data were collected from series of tests consisting of tapping and spiral motor tests. During the second time scale data collection, along smartphone-based measurements patients were video recorded while performing standardized motor tasks according to Unified Parkinson’s disease rating scales (UPDRS).

    At first, the objective of this thesis was to elaborate the state of the art, sensor systems, and measures that were used to detect, assess and quantify the four cardinal and dyskinetic motor symptoms. This was done through a review study. The review showed that smartphones as the new generation of sensing devices are preferred since they are considered as part of patients’ daily accessories, they are available and they include high-resolution activity data. Smartphones can capture important measures such as forces, acceleration and radial displacements that are useful for assessing PD motor symptoms.

    Through the obtained insights from the review study, the second objective of this thesis was to investigate whether a combination of tapping and spiral drawing tests could be useful to quantify dexterity in PD. More specifically, the aim was to develop data-driven methods to quantify and characterize dexterity in PD. The results from this study showed that tapping and spiral drawing tests that were collected by smartphone can detect movements reasonably well related to under- and over-medication.

    The thesis continued by developing an Approximate Entropy (ApEn)-based method, which aimed to measure the amount of temporal irregularity during spiral drawing tests. One of the disabilities associated with PD is the impaired ability to accurately time movements. The increase in timing variability among patients when compared to healthy subjects, suggests that the Basal Ganglia (BG) has a role in interval timing. ApEn method was used to measure temporal irregularity score (TIS) which could significantly differentiate the healthy subjects and patients at different stages of the disease. This method was compared to two other methods which were used to measure the overall drawing impairment and shakiness. TIS had better reliability and responsiveness compared to the other methods. However, in contrast to other methods, the mean scores of the ApEn-based method improved significantly during a 3-year clinical study, indicating a possible impact of pathological BG oscillations in temporal control during spiral drawing tasks. In addition, due to the data collection scheme, the study was limited to have no gold standard for validating the TIS. However, the study continued to further investigate the findings using another screen resolution, new dataset, new patient groups, and for shorter term measurements. The new dataset included the clinical assessments of patients while they performed tests according to UPDRS. The results of this study confirmed the findings in the previous study. Further investigation when assessing the correlation of TIS to clinical ratings showed the amount of temporal irregularity present in the spiral drawing cannot be detected during clinical assessment since TIS is an upper limb high frequency-based measure. 

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    Smartphone-based Parkinson’s disease symptom assessment
  • 19.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Bergquist, Filip
    Nyholm, Dag
    Senek, Marina
    Memedi, Mevludin
    Motion sensor-based assessment of Parkinson’s disease motor symptoms during leg agility tests: results from levodopa challenge2020In: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208, Vol. 24, no 1, p. 111-119, article id 8637809Article in journal (Refereed)
    Abstract [en]

    Parkinson’s disease (PD) is a degenerative, progressive disorder of the central nervous system that mainly affects motor control. The aim of this study was to develop data-driven methods and test their clinimetric properties to detect and quantify PD motor states using motion sensor data from leg agility tests. Nineteen PD patients were recruited in a levodopa single dose challenge study. PD patients performed leg agility tasks while wearing motion sensors on their lower extremities. Clinical evaluation of video recordings was performed by three movement disorder specialists who used four items from the motor section of the Unified PD Rating Scale (UPDRS), the treatment response scale (TRS) and a dyskinesia score. Using the sensor data, spatiotemporal features were calculated and relevant features were selected by feature selection. Machine learning methods like support vector machines (SVM), decision trees and linear regression, using 10-fold cross validation were trained to predict motor states of the patients. SVM showed the best convergence validity with correlation coefficients of 0.81 to TRS, 0.83 to UPDRS #31 (body bradykinesia and hypokinesia), 0.78 to SUMUPDRS (the sum of the UPDRS items: #26-leg agility, #27-arising from chair and #29-gait), and 0.67 to dyskinesia. Additionally, the SVM-based scores had similar test-retest reliability in relation to clinical ratings. The SVM-based scores were less responsive to treatment effects than the clinical scores, particularly with regards to dyskinesia. In conclusion, the results from this study indicate that using motion sensors during leg agility tests may lead to valid and reliable objective measures of PD motor symptoms.

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  • 20.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Bergquist, Filip
    Gothenburg University.
    Nyholm, Dag
    Uppsala University.
    Senek, Marina
    Uppsala University.
    Memedi, Mevludin
    Örebro University.
    Objective assessment of Parkinson’s disease motor symptoms during leg agility test using motion sensors2018Conference paper (Refereed)
    Abstract [en]

    Title: Objective assessment of Parkinson’s disease motor symptoms during leg agility test using motion sensors

    Objective: To develop and evaluate machine learning methods for assessment of Parkinson’s disease (PD) motor symptoms using leg agility (LA) data collected with motion sensors during a single dose experiment.

    Background: Nineteen advanced PD patients (Gender: 14 males and 5 females, mean age: 71.4, mean years with PD: 9.7, mean years with levodopa: 9.5) were recruited in a single center, open label, single dose clinical trial in Sweden [1].

    Methods: The patients performed up to 15 LA tasks while wearing motions sensors on their foot ankle. They performed tests at pre-defined time points starting from baseline, at the time they received a morning dose (150% of their levodopa equivalent morning dose), and at follow-up time points until the medication wore off. The patients were video recorded while performing the motor tasks. and three movement disorder experts rated the observed motor symptoms using 4 items from the Unified PD Rating Scale (UPDRS) motor section including UPDRS #26 (leg agility), UPDRS #27 (Arising from chair), UPDRS #29 (Gait), UPDRS #31 (Body Bradykinesia and Hypokinesia), and dyskinesia scale. In addition, they rated the overall mobility of the patients using Treatment Response Scale (TRS), ranging from -3 (very off) to 3 (very dyskinetic). Sensors data were processed and their quantitative measures were used to develop machine learning methods, which mapped them to the mean ratings of the three raters. The quality of measurements of the machine learning methods was assessed by convergence validity, test-retest reliability and sensitivity to treatment.

    Results: Results from the 10-fold cross validation showed good convergent validity of the machine learning methods (Support Vector Machines, SVM) with correlation coefficients of 0.81 for TRS, 0.78 for UPDRS #26, 0.69 for UPDRS #27, 0.78 for UPDRS #29, 0.83 for UPDRS #31, and 0.67 for dyskinesia scale (P<0.001). There were good correlations between scores produced by the methods during the first (baseline) and second tests with coefficients ranging from 0.58 to 0.96, indicating good test-retest reliability. The machine learning methods had lower sensitivity than mean clinical ratings (Figure. 1).

    Conclusions: The presented methodology was able to assess motor symptoms in PD well, comparable to movement disorder experts. The leg agility test did not reflect treatment related changes.

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  • 21.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Bergquist, Filip
    Nyholm, Dag
    Senek, Marina
    Memedi, Mevludin
    Treatment response index from a multi-modal sensor fusion platform for assessment of motor states in Parkinson's disease2019Manuscript (preprint) (Other academic)
    Abstract [en]

    The aim of this paper is to develop and evaluate a multi-sensor data fusion platform for quantifying Parkinson’s disease (PD) motor states. More specifically, the aim is to evaluate the clinimetric properties (validity, reliability, and responsiveness to treatment) of the method, using data from motion sensors during lower- and upper-limb tests.

    Methods: Nineteen PD patients and 22 healthy controls were recruited in a single center study. Subjects performed standardized motor tasks of Unified PD Rating Scale (UPDRS), including leg agility, hand rotation, and walking after wearing motion sensors on ankles and wrists. PD patients received a single levodopa dose before and at follow-up time points after the dose administration. Patients were video recorded and their motor symptoms were rated by three movement disorder experts. Experts rated each and every test occasions based on the six items of UPDRS-III (motor section), the treatment response scale (TRS) and the dyskinesia score. Spatiotemporal features were extracted from the sensor data. Features from lower limbs and upper limbs were fused. Feature selection methods of stepwise regression (SR), Lasso regression and principle component analysis (PCA) were used to select the most important features. Different machine learning methods of linear regression (LR), decision trees, and support vector machines were examined and their clinimetric properties were assessed.

    Results: Treatment response index from multimodal motion sensors (TRIMMS) scores obtained from the most valid method of LR when using data from all tests. Features were selected by SR, and this method resulted in r=0.95 to TRS. The test-retest reliability of TRIMMS was good with intra-class correlation coefficient of 0.82. Responsiveness of the TRIMMS to levodopa treatment was similar to the responsiveness of TRS.

    Conclusions: The results from this study indicate that fusing motion sensors data gathered during standardized motor tasks leads to valid, reliable and sensitive objective measurements of PD motor symptoms. These measurements could be further utilized in studies for individualized optimization of treatments in PD.

  • 22.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Filip, Bergquist
    Gothenburg University.
    Nyholm, Dag
    Uppsala University.
    Senek, Marina
    Uppsala University.
    Memedi, Mevludin
    Örebro University.
    Feasibility of a multi-sensor data fusion method for assessment of Parkinson’s disease motor symptoms2018Conference paper (Refereed)
    Abstract [en]

    Title: Feasibility of a multi-sensor data fusion method for assessment of Parkinson’s disease motor symptoms

    Objective: To assess the feasibility of measuring Parkinson’s disease (PD) motor symptoms with a multi-sensor data fusion method. More specifically, the aim is to assess validity, reliability and sensitivity to treatment of the methods.

    Background: Data from 19 advanced PD patients (Gender: 14 males and 5 females, mean age: 71.4, mean years with PD: 9.7, mean years with levodopa: 9.5) were collected in a single center, open label, single dose clinical trial in Sweden [1].

    Methods: The patients performed leg agility and 2-5 meter straight walking tests while wearing motion sensors on their limbs. They performed the tests at baseline, at the time they received the morning dose, and at pre-specified time points until the medication wore off. While performing the tests the patients were video recorded. The videos were observed by three movement disorder specialists who rated the symptoms using a treatment response scale (TRS), ranging from -3 (very off) to 3 (very dyskinetic). The sensor data consisted of lower limb data during leg agility, upper limb data during walking, and lower limb data during walking. Time series analysis was performed on the raw sensor data extracted from 17 patients to derive a set of quantitative measures, which were then used during machine learning to be mapped to mean ratings of the three raters on the TRS scale. Combinations of data were tested during the machine learning procedure.

    Results: Using data from both tests, the Support Vector Machines (SVM) could predict the motor states of the patients on the TRS scale with a good agreement in relation to the mean ratings of the three raters (correlation coefficient = 0.92, root mean square error = 0.42, p<0.001). Additionally, there was good test-retest reliability of the SVM scores during baseline and second tests with intraclass-correlation coefficient of 0.84. Sensitivity to treatment for SVM was good (Figure 1), indicating its ability to detect changes in motor symptoms. The upper limb data during walking was more informative than lower limb data during walking since SVMs had higher correlation coefficient to mean ratings.  

    Conclusions: The methodology demonstrates good validity, reliability, and sensitivity to treatment. This indicates that it could be useful for individualized optimization of treatments among PD patients, leading to an improvement in health-related quality of life.

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  • 23.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Halmstad University.
    Feasibility of Using Dynamic Time Warping to Measure Motor States in Parkinson’s Disease2020In: Journal of Sensors, ISSN 1687-725X, E-ISSN 1687-7268, Vol. 2020, article id 3265795Article in journal (Refereed)
    Abstract [en]

    The aim of this paper is to investigate the feasibility of using the Dynamic Time Warping (DTW) method to measure motor states in advanced Parkinson’s disease (PD). Data were collected from 19 PD patients who experimented leg agility motor tests with motion sensors on their ankles once before and multiple times after an administration of 150% of their normal daily dose of medication. Experiments of 22 healthy controls were included. Three movement disorder specialists rated the motor states of the patients according to Treatment Response Scale (TRS) using recorded videos of the experiments. A DTW-based motor state distance score (DDS) was constructed using the acceleration and gyroscope signals collected during leg agility motor tests. Mean DDS showed similar trends to mean TRS scores across the test occasions. Mean DDS was able to differentiate between PD patients at Off and On motor states. DDS was able to classify the motor state changes with good accuracy (82%). The PD patients who showed more response to medication were selected using the TRS scale, and the most related DTW-based features to their TRS scores were investigated. There were individual DTW-based features identified for each patient. In conclusion, the DTW method can provide information about motor states of advanced PD patients which can be used in the development of methods for automatic motor scoring of PD.

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  • 24.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Fleyeh, Hasan
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Memedi, Mevludin
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Feasibility of using smartphones for quantification of Parkinson’s disease motor states during hand rotation tests2019Conference paper (Refereed)
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  • 25.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Memedi, Mevludin
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Nyholm, Dag
    Westin, Jerker
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Verification of a method for measuring Parkinson’s disease related temporal irregularity in spiral drawings2017In: Sensors, E-ISSN 1424-8220, Vol. 17, no 10, article id 2341Article in journal (Refereed)
    Abstract [en]

    Parkinson's disease (PD) is a progressive movement disorder caused by the death of dopamine-producing cells in the midbrain. There is a need for frequent symptom assessment, since the treatment needs to be individualized as the disease progresses. The aim of this paper was to verify and further investigate the clinimetric properties of an entropy-based method for measuring PD-related upper limb temporal irregularities during spiral drawing tasks. More specifically, properties of a temporal irregularity score (TIS) for patients at different stages of PD, and medication time points were investigated. Nineteen PD patients and 22 healthy controls performed repeated spiral drawing tasks on a smartphone. Patients performed the tests before a single levodopa dose and at specific time intervals after the dose was given. Three movement disorder specialists rated videos of the patients based on the unified PD rating scale (UPDRS) and the Dyskinesia scale. Differences in mean TIS between the groups of patients and healthy subjects were assessed. Test-retest reliability of the TIS was measured. The ability of TIS to detect changes from baseline (before medication) to later time points was investigated. Correlations between TIS and clinical rating scores were assessed. The mean TIS was significantly different between healthy subjects and patients in advanced groups (p-value = 0.02). Test-retest reliability of TIS was good with Intra-class Correlation Coefficient of 0.81. When assessing changes in relation to treatment, TIS contained some information to capture changes from Off to On and wearing off effects. However, the correlations between TIS and clinical scores (UPDRS and Dyskinesia) were weak. TIS was able to differentiate spiral drawings drawn by patients in an advanced stage from those drawn by healthy subjects, and TIS had good test-retest reliability. TIS was somewhat responsive to single-dose levodopa treatment. Since TIS is an upper limb high-frequency-based measure, it cannot be detected during clinical assessment.

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  • 26.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Memedi, Mevludin
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Nyholm, Dag
    Senek, Marina
    Medvedev, Alexander
    Askmark, Håkan
    Equilonius, Sten-Magnus
    Bergquist, Filip
    Gonstantinescu, Radu
    Ohlsson, Fredrik
    Spira, Jack
    Sara, Lycke
    Ericsson, Enders
    Quantification of upper limb motor symptoms of Parkinson’s disease using a smartphone2016In: Abstracts of the Twentieth International Congress of Parkinson's Disease and Movement Disorders / [ed] Somayeh Aghanavesi, 2016, Vol. 31, p. S640-, article id 1948Conference paper (Other academic)
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  • 27.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Nyholm, Dag
    Marina, Senek
    Bergquist, Filip
    Memedi, Mevludin
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    A smartphone-based system to quantify dexterity in Parkinson's disease patients2017In: Informatics in Medicine Unlocked, ISSN 2352-9148, Vol. 9, p. 11-17Article in journal (Refereed)
    Abstract [en]

    Objectives: The aim of this paper is to investigate whether a smartphone-based system can be used to quantify dexterity in Parkinson’s disease (PD). More specifically, the aim was to develop data-driven methods to quantify and characterize dexterity in PD. Methods: Nineteen advanced PD patients and 22 healthy controls participated in a clinical trial in Uppsala, Sweden. The subjects were asked to perform tapping and spiral drawing tests using a smartphone. Patients performed the tests before, and at pre-specified time points after they received 150% of their usual levodopa morning dose. Patients were video recorded and their motor symptoms were assessed by three movement disorder specialists using three Unified PD Rating Scale (UPDRS) motor items from part III, the dyskinesia scoring and the treatment response scale (TRS). The raw tapping and spiral data were processed and analyzed with time series analysis techniques to extract 37 spatiotemporal features. For each of the five scales, separate machine learning models were built and tested by using principal components of the features as predictors and mean ratings of the three specialists as target variables. Results: There were weak to moderate correlations between smartphone-based scores and mean ratings of UPDRS item #23 (0.52; finger tapping), UPDRS #25 (0.47; rapid alternating movements of hands), UPDRS #31 (0.57; body bradykinesia and hypokinesia), sum of the three UPDRS items (0.46), dyskinesia (0.64), and TRS (0.59). When assessing the test-retest reliability of the scores it was found that, in general, the clinical scores had better test-retest reliability than the smartphone-based scores. Only the smartphone-based predicted scores on the TRS and dyskinesia scales had good repeatability with intra-class correlation coefficients of 0.51 and 0.84, respectively. Clinician-based scores had higher effect sizes than smartphone-based scores indicating a better responsiveness in detecting changes in relation to treatment interventions. However, the first principal component of the 37 features was able to capture changes throughout the levodopa cycle and had trends similar to the clinical TRS and dyskinesia scales. Smartphone-based scores differed significantly between patients and healthy controls. Conclusions: Quantifying PD motor symptoms via instrumented, dexterity tests employed in a smartphone is feasible and data from such tests can also be used for measuring treatment-related changes in patients.

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  • 28.
    Aghanavesi, Somayeh
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Westin, Jerker
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    A review of Parkinson’s disease cardinal and dyskinetic motor symptoms assessment methods using sensor systems2016Conference paper (Refereed)
    Abstract [en]

    This paper is reviewing objective assessments of Parkinson’s disease(PD) motor symptoms, cardinal, and dyskinesia, using sensor systems. It surveys the manifestation of PD symptoms, sensors that were used for their detection, types of signals (measures) as well as their signal processing (data analysis) methods. A summary of this review’s finding is represented in a table including devices (sensors), measures and methods that were used in each reviewed motor symptom assessment study. In the gathered studies among sensors, accelerometers and touch screen devices are the most widely used to detect PD symptoms and among symptoms, bradykinesia and tremor were found to be mostly evaluated. In general, machine learning methods are potentially promising for this. PD is a complex disease that requires continuous monitoring and multidimensional symptom analysis. Combining existing technologies to develop new sensor platforms may assist in assessing the overall symptom profile more accurately to develop useful tools towards supporting better treatment process.

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    review of parkinson's disease cardinal motor symptoms and dyskinesia using sensor systems
  • 29.
    Agirman, Nesim
    et al.
    Dalarna University, School of Technology and Business Studies, Construction.
    Ali, Mustafa
    Dalarna University, School of Technology and Business Studies, Construction.
    U-värde av isoleringsmaterial i en kassett: En experimentell jämförelse mellan en fönsterkassett som har isolering och en utan isolering2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Insulation and insulation material is one of the most important components in the construction industry and has a wide range of applications and therefore the demand is huge. Because of the high costs on the market, new and different researches take place every day to find alternative insulation materials. The technology make the opportunities greater to find and use cheaper materials. Therefore, it is not un common to see insulations made of different materials every day.

    The purpose of this study is to investigate two Moniflexcassettes, one with insulation and one without, in a climate chamber, to then compare their u-values.

    The results showed the influence on the insulation, that the u-value was lower on the cartridge with the insulation, and therefore a proof that the insulation can use as an additional insulation. This applied especially for windows and glass portions who have a high u-value, which mean that windows and glass portions do not have to change to newer windows with lower u-values.

    The company Isolight´s current u-value of the cassette with the isolation was not the same as with the tested U-value in Högskolan Dalarnas climate chamber. On the cassette without insulation, there has been no comparison between the tested value and the value of the company because the company does not have a u-value for that.

  • 30.
    Ahamed, Anees
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Accelerated Aging of First-surface Enhanced Aluminum Solar Reflectors under Damp Heat Conditions2016Independent thesis Advanced level (degree of Master (Two Years)), 25 credits / 37,5 HE creditsStudent thesis
    Abstract [en]

    Solar reflectors are one of the main components of concentrating solar power systems. With new products being developed, durability studies become a necessity for assessing the feasibility of commercial application. In this project, accelerated aging of three types of first-surface enhanced aluminum reflectors and one type of second-surface silvered thick glass mirror under damp heat conditions is studied. The project is conducted at the Plataforma Solar de Almería (PSA), in collaboration with German Aerospace Center (DLR), and Center for Energy, Environment and Technology (CIEMAT), Spain.

     

    The study is centered on analyzing the effect of soiling on degradation of reflectors. In addition to conventional methods, space resolved specular reflectometry is utilized for comparative purpose. Damp heat test conditions are simulated in a climatic test chamber. Test is conducted with reference to International Electrotechnical Commission standard IEC 62108 10.7a: damp heat test guidelines. The reflector samples are artificially soiled with natural and synthetic test sands of varying composition. Reflector performance is assessed based on the reduction in monochromatic specular reflectance.

     

    From the tests, a comparative assessment of the candidate reflectors is obtained. Aluminum samples suffered higher degradation than silvered glass mirrors. Aluminum reflectors with polymer top coat permanently retained soil residue. It is observed that presence of chlorides and organic components caused corrosion on all the types of reflectors tested. Surface roughening is the reason for performance deterioration in most of the cases. By comparing different reflectance measurement methods, the significance of total area of the measurement spot in the measurement procedures could be highlighted. It is suggested that for studies involving artificial soiling, the grain size of sand is to be factored in.

  • 31.
    Ahlgren, Mathias
    et al.
    SWECO.
    Jansson, Lisa
    SWECO.
    Wredh, Gustav
    SWECO.
    Ranhagen, Ulf
    SWECO.
    Multifunktionella ytor: Översikt med rekommendationer utifrån ett Västeråsperspektiv2018Report (Other academic)
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  • 32.
    Ahlin, Jan
    et al.
    KTH.
    Nilsson, Bengt
    KTH.
    Ranhagen, Ulf
    KTH.
    Arbetsområden och arbetslokaler inom industrin: Programmering och projektering. Program för ett utvecklingsprojekt vid institutionen för arkitektur, KTH1971Report (Other academic)
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  • 33.
    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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  • 34.
    Ahmadi Moghadam, Parham
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Steel Sheet Applications and Integrated Heat Management2016Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Increasing energy use has caused many environmental problems including global warming. Energy use is growing rapidly in developing countries and surprisingly a remarkable portion of it is associated with consumed energy to keep the temperature comfortable inside the buildings. Therefore, identifying renewable technologies for cooling and heating is essential. This study introduced applications of steel sheets integrated into the buildings to save energy based on existing technologies. In addition, the proposed application was found to have a considerable chance of market success.

    Also, satisfying energy needs for space heating and cooling in a single room by using one of the selected applications in different Köppen climate classes was investigated to estimate which climates have a proper potential for benefiting from the application. This study included three independent parts and the results related to each part have been used in the next part.

    The first part recognizes six different technologies through literature review including Cool Roof, Solar Chimney, Steel Cladding of Building, Night Radiative Cooling, Elastomer Metal Absorber, and Solar Distillation. The second part evaluated the application of different technologies by gathering the experts’ ideas via performing a Delphi method. The results showed that the Solar Chimney has a proper chance for the market.

    The third part simulated both a solar chimney and a solar chimney with evaporation which were connected to a single well insulated room with a considerable thermal mass. The combination was simulated as a system to estimate the possibility of satisfying cooling needs and heating needs in different climate classes. A Trombe-wall was selected as a sample design for the Solar Chimney and was simulated in different climates. The results implied that the solar chimney had the capability of reducing the cooling needs more than 25% in all of the studied locations and 100% in some locations with dry or temperate climate such as Mashhad, Madrid, and Istanbul. It was also observed that the heating needs were satisfied more than 50% in all of the studied locations, even for the continental climate such as Stockholm and 100% in most locations with a dry climate. Therefore, the Solar Chimney reduces energy use, saves environment resources, and it is a cost effective application. Furthermore, it saves the equipment costs in many locations. All the results mentioned above make the solar chimney a very practical and attractive tool for a wide range of climates.

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  • 35.
    Aishwarya, Veena Aishwarya
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Effects of Soling on the Solar Radiation Sensors for Indian Climatic Conditions2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The satisfaction and elation that accompany the successful completion of any task

    would be incomplete without the mention of the people who have made it possible. It is a great

    privilege to express my gratitude and respect to all those who have guided me and inspired me

    during the period of the project work.

    First and foremost, I express my sincere gratitude to my University professor

    Fiedler Frank, Program Coordinator, Dalarna University, Borlange, Sweden who encouraged

    and permitted me to have my project in the second semester itself.

    I owe a lot to my supervisor Rönnelid Mats, Associate Professor of Energy and

    Environmental Technology, Dalarna University, Borlange, Sweden for his valuable

    suggestions, constructive criticism and encouragement for the project.

    I deem it to be a great privilege in thanking my external supervisor Dr.Richard

    Meyer, Founder and Managing Director (Suntrace GmbH) and Marko Schwandt, Advisor, Solar

    Expert en Suntrace GmbH for giving an opportunity to work under him. Their guidance,

    academic freedom and co-operation have helped me in completing my project.

    My heartfelt thanks to Dr. S. Gomathinayagam, Director General, NIWE and Dr.G.Giridhar,

    Deputy Director General & Head, SRRA department, NIWE for providing me the necessary

    facilities for the completion of my masters project. I am indebted to Dr.Indradip Mitra,Senior

    Technical Advisor at GIZ GmbH and Kaushal Chhatbar, Project Manager, Project

    Development at Suntrace GmbH , for their valuable suggestions and support.

    I also pay my sincere regards to the staffs of SRRA department for their support

    during the period of my project. I owe a lot to my family, who always motivated me and brought

    me to this level. Finally I submit my obeisance to THE ALMIGHTY for constantly supporting

    me and blessing me with the necessary strength to carry out this research.

  • 36.
    Ajayi, Adeyemi Kazeem
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    New Housing Developments: A Localisation Strategy considering Energy-Efficiency from an Urban Structure and Transport Perspective for the city of Falun2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There are several considerations when planning new housing developments,

    and resultant problems require critical analysis. This thesis has focused on

    studying some part of the potential issues in the case of a project in the city of

    Falun.

    The focus has been on energy and greenhouse gases (GHG)-efficient structures,

    through the analysis of the relationship between the transport system and

    residential development that can contribute to the reduction in emission’s harmful

    effect on human health and the environment. The overall aim has been on the

    sustainable location of housing with regards to transport energy, and it included

    the review of densification in the development of city planning as a measure.

    These courses of action, together with other considered measures been

    explored, are to provide solutions which can contribute to the livability, a greener

    environment and lower the levels of GHG, as well as the use of energy from

    transport.

    Densification is a significant concern when planning for future infrastructure and

    developments in a city. It is not just about housing; dense cities use less energy

    and the denser a city, the more sustainable they set to be.

    The significance of the transport system in an urban environment is enormous

    due to the level of its impact as a major user of energy, specifically petroleum

    product consumption. It is essential to note the importance of the effect that GHG

    and energy use from transport has on the health and wellbeing of city inhabitants,

    the society, as well as humans in general. Therefore, it is most important to strive

    to reduce the need for energy use from transport and to lower the levels of

    transport GHG.

    The city of Falun is planning for new housing development, with comprehensive

    plans for future urban development of areas within and around the city. There is

    a current proposal for the densification of central areas; however, they are also

    proposing new large areas on the periphery, which may be counter-productive

    from a transport point of view.

    This circumstance could lead to more car travel within and around the city, which

    leads to increases in carbon dioxide (CO2) emissions and fuel use, and in turn,

    increased in environmental pollution. Thus, the thesis purpose has been to

    investigate the energy use and carbon dioxide emissions in related scenarios.

    The aim is studying the proposed new housing development potentials to reduce

    car travel through an urban strategy measure such as smart growth; therefore,

    the selection of the following research questions below:

    • Will the proposal in the detailed, comprehensive plan lead to transportation that

    is more or less energy-efficient than today? And Is the proposed development in

    line with previous empirical findings in the research literature?

    • Can the amount of car travel be reduced by planning for a different location

    strategy for future residential development in Falun?

    • Can this analysis be made roughly using simple tools that are easy to use for

    urban planners or architects (not only for advanced GIS-engineers and

    researchers)

    iv

    A literature review facilitates reflection on these issues and studies measures for

    strategies which could be a better alternative when exploited in such or similar

    situation for preferable development. Thus, it’s exploitation in the thesis work.

    This research has been carried out by performing an investigation of the new

    housing development proposal, specifically through analyses of the assumed

    additional usage of passenger cars in the ongoing planned area. Possible

    alternatives are, therefore, examined, e.g. in the frame of options such as

    spreading the housing system into more centrally located and connecting areas,

    improving the relationship between the public transport system and new

    residential development so they could work in tandem.

    From the carried-out work, it has possible to be able to identify some disharmony

    in the ongoing development plans as part of the possible future problems, i.e. the

    case of possible unexploited solution for air pollution from transport energy,

    related issues, and so on. An in-depth interview with two of the Falun city office

    staffs and planners also opens-up on the problems of decision-makers and land

    use policy. Also, site visits provide the perspectives of present and potential

    owners who participated in an impromptu interview.

    Meanwhile, the presented results show that the overall total energy usage

    becomes higher per person with the Falun city´s ongoing-planning proposal, but

    lower with the designed alternative planning scenario. The results were derived

    through calculations, using the “Model for calculating energy use and carbon

    dioxide emissions in different scenarios’’ for generating scenarios that take

    modal split into account as seen in the data, calculation and result’s chapter,

    further in the thesis.

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  • 37. Akenine, Daniel
    et al.
    Stier, Jonas
    Dalarna University, School of Humanities and Media Studies.
    Människor och Ai: En bok om artificiell intelligens och oss själva2018 (ed. 1)Book (Other (popular science, discussion, etc.))
  • 38.
    Alayan, Sophia
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Design of a PV-Diesel Hybrid System with Unreliable Grid Connection in Lebanon2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is a study on integration of photovoltaic generators into an existing diesel-unreliable grid connected system at the Lebanese village of Khiam. The main goal of implementing PV-diesel hybrid system is to reduce diesel consumption and the import of fossil fuel used in electricity power supply. Before designing the system, it is necessary to create a load profile for 120 households and pre-design the size of the PV generator, the capacity of storage system and inverter type/size selection. The load profile data is based on the average of monthly energy consumption gathered from Khiam village households.

    Detailed simulations and financial analysis are performed with HOMER to compare different systems and their viability. The simulations include four different designs starting from the existing system, diesel generator with unreliable grid, followed by PV generator and unreliable grid, PV and diesel generator and ended with the complete hybrid system. Once the Hybrid system is determined a detailed design is done to optimize the lowest cost PV-diesel hybrid system. The final simulated PV-diesel hybrid system is suggested with a PV capacity of 270 kWp, existing diesel capacity with 200 kVA, an inverter output of 115 kW and battery bank nominal capacity is 1872 kWh. The system renewable fraction is 53% and the project life cycle is 25 years. The PV-diesel hybrid system is projected to produce electricity at a cost of 0.12 USD/kWh. This cost is significantly lower than the 0.26 USD/kWh paid to the diesel operator, as well as lower than 0.13 USD/kWh paid to the utility grid.

    In addition, and according to the given information from the owner, an estimated diesel consumption of 104000 ltr/year, the simulation result shows diesel consumption at 40000 ltr/year. The reduced carbon dioxide production by 65%, from 776 to 272 tons per year, provides further justification for the PV installation in a commercial PV-diesel hybrid system.

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  • 39.
    Albatrok, Husam
    Dalarna University, School of Technology and Business Studies, Construction.
    Våningspåbyggnad i trä på befintligt betong bostadshus2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During the years 1965–1975, the politicians chose to start a large housing development, which resulted in a million homes being built in 10 years. It was called Miljonprogrammet. Tjärna Ängar is an area located in Borlänge where some of those building took place. The area has 1,179 apartments in 3-storey slab houses and the Tjärna Angar area is divided into three different blocks: Kornstigen, Klövern and Plogstigen. These are built next to Tjärna center, with good bus connections to the rest of Borlänge.

    The purpose of this work was to produce a storey building for an existing slab of concrete. the reference building is at Kornstigen 25.

    With the help of Drawings, the existing building will be studied. Information search will be done on the subject regarding floor buildings and the history of the million program and construction. Walls and ceilings will be developed and an extension for the lift. Finally, a model is made in a Cad-programe that illustrates the result.

    The result of the storey building was a wooden walkway with a total of 10 apartments. Two corner apartments became three rooms and the kitchen while the rest became two rooms and kitchens in varying surfaces. Storey building wood is a good way to be able to build on the heigt, but many aspects considered and be and checked before a storey buildig takes place.

  • 40.
    Alfadel, Usama
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Analysing the Peak Shaving Effect and the Increase in SelfConsumption and Self Sufficiencyof Battery Storage When Coupledto a Single Family House2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aims of the study were to investigate the increase in self-consumption and self-sufficiency and the peak shaving effect of batteries when added to a PV system dimensioned to supply the electric demand of a low energy house built in Sweden. The simulated batteries were Li-ion and the study had a 15-minutes temporal resolution. The study took only the technical aspect of batteries into account and disregarded the economic aspect. A data set of measurements from two near-zero-energy houses built by the Research Institute of Sweden (RISE) was used as inputs. The first house provided measured load profile for an automated load and measured PV production from its 3.6 kW

    p system, the second house provided a load profile for a normal human interactive load. The measured PV production from the 3.6 kWp PV system was compared to the PV production from a simulated 3.6 kWp system taken from PVsyst and System Advisor Model (SAM) and by using different weather data profiles for the simulations. The global irradiance values from the used weather profile data were compared to demonstrate the difference in its values and its effect on the simulated PV production. This comparison between the measured PV production and the simulated one was done because most of the PV simulation software does not take measured PV production as input but they simulate their own PV production based on their built-in weather data; including the software used in this study SAM. The first house with the automated load had an annual energy consumption of Ca. 3600 kWh / Year. The second house with its human interactive load had an annual energy consumption of Ca. 6000 kWh / Year. The load profile was taken as a whole and then divided to different types; heat pump, ventilation and remaining load which represents house hold services. The effect of the input load profile types and its temporal resolution was clarified; this effect came in consistency to what was concluded from the literature review. Different simulations were done varying battery sizes, voltage level, coupling method, dispatch algorithm and other parameter. Three different dispatch algorithms were used for the simulations; two are designed for peak shaving and are built-in tools in SAM while the third algorithm is called Target Zero and designed for maximizing self-consumption and self-sufficiency, it was found in a reference so it was executed in MS Excel. Each of the algorithms used was found to affect both the peaks and the self-consumption and self-sufficiency of the system after adding the batteries compared to before, one as a major effect and the other as a byproduct effect. The peak shaving results varied by varying the batteries and the dispatch algorithm used, for the peak shaving algorithms from SAM, a general decrease in peaks value was reached. For the Target Zero algorithm which optimizes on self-consumption and self-sufficiency, a decrease in the number of the peaks was reached. Both decreases happened by increasing battery sizes. For the self-consumption and self-sufficiency effect, an increase happened with its highest value for 7.2 kWh batteries and by using the three different algorithms. The effect of the load type was also demonstrated by comparing the simulations results for the heat pumps from both houses since both heat pumps were found to have the highest effect on the results. The study was concluded by emphasizing the added values of batteries when coupled to a behind-the-meter PV system. The study could have been more precise and added more information to this field if it had a 1 minute temporal resolution simulations, but patching one minute temporal resolution load profile takes a long time. Working with one minute load profile requires one minute weather profile for the PV simulation which is normally only commercial. Also, having a weather station installed at the house to measure the solar irradiance to be used in the simulation instead of using different weather profiles would have added more accuracy to this paper.

  • 41.
    Alfredsson, Clara
    et al.
    Dalarna University, School of Technology and Business Studies, Graphic Arts Technology.
    Pettersson, Karin
    Dalarna University, School of Technology and Business Studies, Graphic Arts Technology.
    Sportevenemangets nyhetsbrev: Råd om utformningen av nyhetsbrev2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Society is becoming more digitized, which has led to that several companiesneed to change their marketing. Many companies promote themselves throughdigital channels, one of these are e-mail. A way to market themselves throughe-mail is with newsletters. The research on e-mail marketing is far morecomprehensive than the research specifically about newsletters, which makesnewsletters to an interesting subject to study more closely. The study aims toexamine what advice regarding the design of the newsletter covers and if theadvices is suited specifically for sports events newsletters. The study also aimsto examine if FIS Nordic World Ski Championship's public newsletters followsthe selected advices and if it prefers of the receivers.To answer the questions of this study, an identification, a comparison and asurvey has been done. The identification was done through an informationsearch and 65 advices were found. Six general advice were selected andcompared to the Nordic Ski Championship's public newsletters. New modifiedversions of parts of the newsletters were created based on whether theyfollowed the six general advices or not. The modified versions and the originalversions were put together as pairs. In the survey that was published on aFacebook page and group administered by the Nordic Ski Championships,participants selected which version they preferred. The identification resulted inthat many of the advices covered the design of the newsletters text and advicesuited specifically for sport events was rare. The Nordic Ski Championshipsnewsletters followed four of the six general advices and the version of thenewsletters that followed the advice was preferred in three of six cases.

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  • 42.
    Alhamwi, MHD Mouaz
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Evaluating the Economic Feasibility for utilizing PV Power Optimizers in Large-scale PV Plants for The Cases of Soiling, Mismatching, and Degradation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The solar PV modules are influenced by a variety of loss mechanisms by which the energy yield is affected. A PV system is the sum of individual PV modules which should ideally operate similarly, however, inhomogeneous soiling, mismatching, and degradation, which are the main focus in this study, lead to dissimilarities in PV modules operating behavior and thus, lead to losses which will be assessed intensively in terms of energy yield.

    The dissimilarities in PV modules are referred to the ambient conditions or the PV modules

    characteristics which result in different modules’ maximum power point (MPP) and thus, different currents generated by each PV modules which cause the mismatching. However, the weakest PV module current governs the string current, and the weakest string voltage governs the voltage.

    Power optimizers are electronic devices connected to the PV modules which adjust the voltages of the PV modules in order to obtain the same current as the weakest module and thus, extract

    the modules’ MPP. Hence, the overall performance of the PV plant is enhanced. On the other hand, the power optimizers add additional cost to the plant’s investment cost and thus, the extra energy yield achieved by utilizing the power optimizers must be sufficient to compensate the additional cost of the power optimizers. This is assessed by designing three systems, a reference system with SMA inverters, a system utilizes Tigo power optimizers and SMA inverters, and a system utilizes SolarEdge power optimizers and inverters. The study considers four different locations which are Borlänge, Madrid, Abu Dhabi, and New Delhi.

    An Excel model is created and validated to emulate the inhomogeneous soiling and to evaluate the economic feasibility of the power optimiz

    ers. The model’s inputs are obtained from PVsyst and the precipitation data is obtained from Meteoblue and SMHI database.

    The economic model is based on the relation between Levelized Cost of Electricity (LCOE) which will be used to derive the discount rate. Graphs representing the discounted payback period as a function of the feed-in tariff for different discount rates is created in order to obtain the discounted payback period.

    The amount of extra energy yielded by the Tigo and the SolarEdge systems is dependent on the soiling accumulated on the PV modules. Relative to the reference system, 6.5 % annual energy gain by the systems utilizing the power optimizers in soiling conditions, up to 2.1 % in the degradation conditions, and up to 9.7 % annual energy gain at 10 % mismatching rate. The extra energy yield is dependent on the location, however, the Tigo and the SolarEdge systems have yielded more energy than the reference system in all cases except one case when the mismatch losses is set to zero.

    The precipitation pattern is very influential, and a scare precipitation leads to a reduction in the energy yield, in this case, the Tigo and the SolarEdge systems overall performance is enhanced and the extra energy gain becomes greater.

    The Tigo system yield slightly more energy than the SolarEdge system in most cases,

    however, during the plant’s lifetime, the SolarEdge system could become more efficient than the Tigo system which is referred to the system’s sizing ratio. The degradation of the system or the soiling accumulation decreases the irradiation and thus, a slightly oversized PV array become suitable and deliver an optimal power to the inverters.

    The SolarEdge system is feasible in all scenarios in terms of LCOE and discounted payback period, although its slightly lower performance relative to the Tigo system, this is referred to its low initial cost in comparison to the other systems. The Tigo system is mostly infeasible although it yields more energy than the reference and the SolarEdge systems, this is referred

    iii

    to its relatively high initial cost. However, feed-

    in tariffs higher than 20 € cent / kWh make

    all systems payback within less than 10 years.

    The results have overall uncertainty within ± 6.5 % including PVsyst, Excel model, and the

    precipitation uncertainties. The uncertainty in the degradation and the mismatching

    calculations is limited to PVsyst uncertainty which is ± 5 %. The uncertainties in LCOE in

    the location of New Delhi, since it is the worst-case scenario, are 5.1 % and 4 % for the

    reference and the systems utilizing power optimizers, respectively.

    Consequently, accommodating the uncertainties to the benefits gained by utilizing power

    optimizers indicates that the energy gain would oscillate in the range of 6 % - 6.9 % for the

    soiling calculations, 2 % - 2.2 % for the degradation simulations, and 9.2 % - 10.2 % for the

    mismatching simulations at 10 % mismatchrate.

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  • 43.
    Al-Hashimi, Mazin
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Modelling Installation Cost for Rooftop PV Systems2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The cost of installation of photovoltaic (PV) systems is a substantial fraction of the total cost of the project and the same is increasing with reducing cost of PV modules. This study essentially deals with the cost of installation of rooftop PV systems and presents a cost model for it, based on data collected for more than 700 projects of different capacities, roof types, circumstances, and locations in Sweden. The presented cost model shall give reasonably accurate estimations about the costs associated with the main elements of the process of rooftop PV systems installation, such as labour, shipping, equipment, travel, and accommodation, for different situations as a function of few important variables such as system capacity, roof type, distance to the installation location, etc. The weighted share of cost of the different elements of the cost model out of the total cost of installation was determined. Several relationships between different elements and variables were examined to find relationships that can help to better understand the process of installation and to develop the cost model. The variations in time required per unit system capacity have been examined for several processes of rooftop PV systems installation, to investigate about potential for reduction in the time and thus the cost due to economies of scale.

  • 44.
    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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  • 45.
    Ali, Samir
    et al.
    Dalarna University, School of Technology and Business Studies, Construction.
    Hanna, David
    Dalarna University, School of Technology and Business Studies, Construction.
    Hjälpmedel till resenärer i kollektivtrafiken som inte kan ta till sig vanliga skyltar på ett enkelt sätt2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report aims at investigating how traffic management can help disabled and elderly. Although more than 800,000 people travel with SL every day, many elderly and disabled find it difficult to travel using public transportation. Through interviews, different associations representing different disabilities have reported that they feel a lack of information and they feel insecure. Many choose not to travel with public transportation. The investigation has resulted in two different solutions, the advantages and disadvantages of the different solutions are discussed as well. A WEFEEL bracelet that communicates with both the passenger and the bus driver via signals to facilitate the perception that the correct bus is on its way, signal if the traveller has a need for assistance, etc. The second solution proposal WEFIND is ground plates with diodes in the form of arrows that show the path when traffic disturbances occurs and redirects the passengers. Both solutions work for many different groups and also for travellers without special needs (arrows). The solutions take into consideration the environmental issue but have not been further investigated in terms of instalment and economy. The conclusion is that the suggested solutions can help travellers feel safer and thus travel more using public transport.

  • 46.
    Alkhado, Luqman
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Boussaa, Youcef
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Heat transfer tests on EPS material and massive timber wall component2018Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Timber walls are known to be an energy efficient component in the building envelope.

    These building elements are essential in the passive design and have been pointed out to

    their ability to regulate the indoor climate and reduce energy demand. Heat transfer

    measurements of thermal transmittance value of Iso-timber wall component have been

    performed with the climate chamber at three temperature differences. The influence of

    temperature variations on the thermal conduction of the wall were investigated. The

    temperature on the warm side was kept at room temperature 20 °C while the cold side

    temperature was decreased from 0 C to -20 C during the tests. As the temperature

    difference is increased, the thermal transmittance value of the timber wall component

    decreased slightly due to decrease in the thermal conductivity value. The effect of density

    and porosity on the thermal conductivity may be related to the presence of air voids and

    cell boundaries inside the timber wall. Results have showed that the U-value of the timber

    wall component decreases at higher temperature differences which indicates the higher

    degree of insulation of the timber wall component.

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  • 47.
    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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  • 48.
    Alkhuder, Juma
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Johansson, Sandra
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Prestandaanalys vid rengöring av värmeväxlare i fjärrvärmecentral för småhus: Fallstudie på rengöring av en värmeväxlare för småhus2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fouling of plate heat exchangers in district heating substations reduces the cooling of circulating water in the district heating network. This increases energy production at the district heating plant, which results in increased greenhouse gas emissions. The amount of fouling depends on the quality of the water and material in the system. This study evaluates the performance change of heat exchangers in district heating substations for residential housing before and after cleaning, and new heat exchangers. Performance is measured in the laboratory by measuring temperatures before and after cleaning at specified flows. The evaluation includes performance change of UA-value, Temperature efficiency, Effectiveness NTU and possible impact on greenhouse gas emissions from Borlänge Energi's district heating system.The results of the study show that cleaning of residential heat exchangers with the CIP method has a certain effect on both the tap water heat exchanger and the heat exchanger. For the heat exchanger, the improvement in performance is small where the UA-value increases between 10-202 W/˚C compared to the tap water heat exchanger where it is between 205-870 W/˚C. The highest effect is the cleaning on the tap water heat exchanger at higher flow. The heat transfer is equivalent for a new heat exchanger and the cleaned one.Reduced return temperature from the district heating network leads to an improved efficiency at the district heating plant, which contributes to a reduction in the amount of greenhouse gas emissions. According to the results and calculations performed in the study, by cleaning the return temperature can be reduced by 2,3 ˚C ± 0.4% from the district heating substations in residential houses to Borlänge Energy's district heating network.Cleaning of tap water heat exchangers can be an alternative to switching to a new one for the homeowner, provided that the price for cleaning is lower than buying a new one and that the district heating system has flow rate tariff. However, this does not apply to the heat exchanger where the difference in heat transfer between one with fouling and a new or cleaned is marginal.

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  • 49.
    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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  • 50.
    Almsalati, Hussam
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Life cycle assessment of villas made by Fiskarhedenvillan, comparison between wood and brick facade2018Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Awareness of climate change has resulted in enormous challenges for developed and

    developing countries. The frightening truth about our environmental situation has led to

    investigations of the causes of these changes and to obstruct these sources gradually but

    quickly. The alarming increase of average temperature of the earth has caused much worry

    around the world. Gas emissions in the atmosphere greatly affect the environment, where

    CO

    2 emissions is one of the most serious factors contributing to the global warming

    potential. As the building sector emits 40% of global energy use and one-third of global

    greenhouse gas emissions, engineers must be educated to choose the best materials that

    lead to reducing CO

    2 emissions. This means selecting materials that have less negative

    impact on the environment and are more “environmentally friendly”.

    This study shows how much CO

    2e emissions are released into the atmosphere from a

    wooden structure villa that consists of two stories, a storage and a garage, with a total area

    of 229.6m2. The results of this case will be compared to a second case, where the external

    wooden siding is replaced with brick veneer. This result of this comparison provides us

    with a guideline in for how the selected materials impact the environment, illuminating the

    importance in choosing the right materials according to their CO

    2e emission levels. In this

    way, the building sector can actively work to reduce the environmental impact.

    To achieve these goals, this study performed via life cycle assessment LCA methodology

    by using the One-Click LCA program. LCA is identified as a technique to assess the

    environmental impact and resources used through a product’s life cycle. This study utilized

    the LCA methodology (cradle to grave), which means starting from the extraction of raw

    materials, to product production, manufacturing, product usage and its end of life. The

    study lifespan was estimated to be 50 years.

    The results of the study verify that the wooden villa is more environmentally friendly than

    the villa made of brick, where carbon dioxide equivalent emission can be reduced to more

    than half by utilizing wood. Implementing the life cycle assessment study to any building

    aids in making the decision to choose the right materials for building according to CO

    2e

    emission. And in this way, the environmental impact caused by the building sector will be

    greatly reduced.

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