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  • Engström, Karl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Skoglund Lartell, Maximilian
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Evaluating locations for subsurface dams: Case study on Storsudret, Gotland2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Due to precipitation poor winters and springs and over-exploitation of groundwater reserves during the summer months as a consequence of tourism, the island of Gotland has experienced fresh water shortages during recent years which has led to harsh restrictions in the use of municipal water. In order to find a solution to the islands fresh water problems, the region of Gotland and the Swedish Environmental Institute (IVL) have initiated a project in which the southernmost part of Gotland, Storsudret, will be used as a test site for new methods of sustainable freshwater storage and extraction methods.

    A, for Sweden, new method currently being investigated is the use of subsurface dams in order to increase the storage capacity of soil groundwater, thus increasing the possible extractions. Methods for finding suitable sites for subsurface dams has been investigated by Imran Jamali, 2016, and Ludvig Almqvist, 2017. There is however a need in further investigating and developing methods for subsurface dam location. This master thesis has focused on performing on-site data collection and on the use of groundwater flow model to evaluate the possibility of placing a subsurface dam on Storsudret, as steps in a method to localize areas suitable for subsurface dams.

    On site data was collected through resistivity measurements and water level measurements. This was used as input data for the flow model, MIKE SHE, together with more general GIS-data available. Flow modelling was performed during the period 2015-2018, which included the initially dry years of 2015-16 and the summer of 2017, and the more precipitation rich second half of 2017 and spring of 2018. Subsurface dams were modelled to investigate the results on the surroundings.

    The result did not show any obvious locations for the placement of a subsurface dam within the modelled area. The site considered to be most suitable for dam placement was modelled but showed only a rather small additional stored volume. However, the model result indicated that large possibilities for freshwater extraction already could be present in an existing geological formation in the area, even without the presence of a subsurface dam.

    As a tool for finding the specific location of groundwater dams, it was concluded that MIKE SHE gives a good overview over the general hydrogeological features and flow paths. Thus, it is a valuable tool when it comes to finding interesting sites for further investigations. However, due to problems in obtaining detailed enough input data, the model is considered to be less suitable for finding specific locations for dam placement when investigating a larger domain.

  • Fay, Dominik
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Membership Privacy in Neural Networks for Medical Image Segmentation2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Neural networks are known to memorize parts of their training set. Therefore, whenever sensitive information is involved, releasing a trained network may constitute a privacy breach. In this thesis, we use differential privacy to train neural networks that provably protect the identity of participants. In particular, we address the problems that arise in the domain of image segmentation. Here, previous methods needed to add unreasonably high noise to protect privacy, due to the high output dimensionality. We use dimensionality reduction to lower the required noise level, resulting in a better privacy-utility trade-off. We prove the privacy guarantee formally and evaluate predictive performance empirically on a synthetic dataset.

  • Paschen, Jeannette
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Paschen, Ulrich
    Pala, Erol
    Kietzmann, Jan
    Artificial intelligence (AI) and value co-creation in B2B sales: Activities, actors and resourcesManuscript (preprint) (Other academic)
    Abstract [en]

    Artificial intelligence (AI) allows business actors to exchange resources, particularly information and knowledge, to strengthen their businesses. These AI-enabled value co-creation processes are playing a substantial role in the business-to-business (B2B) sales context. However, little is known about the mechanisms and the process of value co-creation enabled by AI. On this basis, this study addresses this gap by employing Service-Dominant Logic to understand value co-creation with AI. This study identifies the value co-creation process and provides an understanding of the actors, activities and resources during the usage of AI to create value in B2B sales. The study also identifies several limitations of AI, such as value co-creation is heavily dependent on human activities and resources. Lastly, we suggest that managers continue to manage customer expectations when using AI for value co- creation and highlight the necessity of human actors and resources in the value co-creation process.

  • Paschen, Jeannette
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Kietzmann, Jan
    Kietzmann, Tim C.
    Unpacking artificial intelligence – How the building blocks of artificial intelligence (AI) contribute to creating market knowledge from big dataManuscript (preprint) (Other academic)
    Abstract [en]

    Purpose:

    This study explains artificial intelligence (AI) and its contributions to creating market knowledge from big data. Specifically, this study describes the foundational building blocks of any AI technology, their interrelationships and the implications of different building blocks with respect to creating market knowledge, along with illustrative examples.

     

    Design/methodology/approach:

    The study is conceptual and proposes a framework to explicate the phenomenon AI and its building blocks. It further provides a model of how AI contributes to creating market knowledge from big data.

     

    Findings:

    The study explains AI from an input–processes–output lens and explicates the six foundational building blocks of AI. It discusses how the use of different building blocks transforms data into information and knowledge. It proposes a conceptual model to explicate the role of AI in creating market knowledge and suggests avenues for future research.

     

    Practical implications:

    This study explains the phenomenon artificial intelligence, how it works and its relevance for creating market knowledge for B2B firms.

     

    Originality/value:

    The study contributes to the literature on market knowledge and addresses calls for more scholarly research to understand AI and its implication for creating market knowledge.

  • Pitt, Christine
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Plangger, Kirk
    King's College Longon, King's Business School.
    Eriksson, Theresa
    Luleå University of Technology.
    Accommodation eWOM in the Sharing Economy: Automated Text Comparisons from a Large SampleManuscript (preprint) (Other academic)
    Abstract [en]

    Across many industries, individuals are increasingly relying on customer ratings and reviews on social media. While customer reviews often provide detailed diagnostic information about experiences, customer ratings often reduce the experience down to a simple number. Moreover, there is evidence to support that customer rating inflation is occurring on social media sites over time, especially in the sharing economy, and especially with regard to travel and tourism experiences. This paper conceptualizes how customer experiences are reduced into customer reviews and further abridged into customer ratings in both the traditional and sharing economy contexts. We propose that customers observe how service providers present themselves as a professional (established chain hotel) or amateur (owner operated vacation rental apartment), and then form different service expectations and perceptions accordingly. We investigate 55,110 customer reviews and ratings of New York City’s accommodation providers and indeed find evidence of rating inflation over the eight years studied.

  • Pitt, Christine
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Mulvey, Michael
    University of Ottawa, Tefler School of Business.
    Kietzmann, Jan
    University of Victoria, Gustavson School of Business.
    Quantitative insights from online qualitative data: An example from the health care sector2018In: Psychology & Marketing, ISSN 0742-6046, E-ISSN 1520-6793, Vol. 35, no 12, p. 1010-1017Article in journal (Refereed)
    Abstract [en]

    Among the deluge of online data generated by users in the form of text on social media sites, health care reviews are among the most common, and potentially, the most insightful. Patients review and comment on the experiences with procedures as varied as hysterectomies, colonoscopies, and chemotherapy. In their attempts to reduce the uncertainty associated with medical treatments, many patients nowadays also turn to social media, where they rely on the experiences articulated by other patients. In this study, IBM Watson is used to examine how knee replacement patients talk about their emotions and express sentiment through their comments online. Then, a latent class cluster modeling procedure is used to segment these patients into distinct groups, according to their emotions (anger, disgust, fear, happiness, sadness, and surprise), sentiment, and their overall satisfaction with knee replacement surgery. The findings show how qualitative online data can be transformed into quantitative insights regarding underlying market segments, which could then be targeted through different strategies by both marketers and health care practitioners.

  • Pitt, Christine
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Gender and the CMO: Do the Differences Make a Difference?2019In: Journal of Strategic Marketing, ISSN 0965-254X, E-ISSN 1466-4488Article in journal (Refereed)
    Abstract [en]

    Despite efforts to address the lack of female representation in execu- tive leadership roles, the number of women in leadership roles is still low in comparison to men. Data in the form of online interviews were collected for a sample of 69 CMOs from the World’s Most Influential CMO’s report by Forbes Magazine and analyzed using the automated text analysis software, LIWC, employing the dimensions of Analytic, Clout, Authentic, and Tone. A series of ANOVAs was conducted to determine the impact of gender on these dimensions. Clout and Authentic were significantly impacted by the gender of the CMO. The paper considers two gender communication theories that could potentially explain these differences. The paper concludes by dis- cussing managerial implications, acknowledging the limitations, and identifying avenues for future research.

  • Pitt, Christine
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Bal, Anjali
    Babson College, Department of Marketing.
    Plangger, Kirk
    King's College London, King's Business School.
    New Approches to Psychographic Consumer Segmentation: Exploring Fine Art Collectors Using Artificial intelligence, Automated Text Analysis and Correspondence Analysis2020In: European Journal of Marketing, ISSN 0309-0566, E-ISSN 1758-7123Article in journal (Refereed)
    Abstract [en]

    Purpose – While the motivation for collecting art has received considerable attention in the literature, less is known about the characteristics of the typical art collector. This paper aims to explore these characteristics to develop a typology of art consumers using a mixed method approach over several studies.

    Design/methodology/approach – This is achieved by analyzing qualitative data, gathered via semi- structured interviews of art collectors, and quantitatively by means of natural language processing analysis and automated text analysis and using correspondence analysis to analyze and present the results.

    Findings – The study’s findings reveal four distinct clusters of art collectors based on their “Big Five” personality traits, as well as uncovering insights into how these types talk about their possessions.

    Research limitations/implications – In addition to contributing to the arts marketing literature, the findings provide a more nuanced understanding of consumers that managers can use for market segmentation and target marketing decisions in other markets. The paper also offers a methodological contribution to the literature on correspondence analysis by demonstrating the “doubling” procedure to deal with percentile data.

    Practical implications – In addition to contributing to the arts marketing literature, the findings provide a more nuanced understanding of art collectors that managers can use for market segmentation and target marketing decisions. The paper also offers a methodological contribution to the literature on correspondence analysis by demonstrating a non-traditional application of correspondence analysis using the “doubling” procedure. Buyer behavior in the fine art market is not exhaustively studied. By understanding the personality traits of consumers in the art market, sales forces can better provide assistance and product to consumers. Further, understanding the personalities of consumers is better for art retail spaces to better serve consumers.

    Originality/value – This paper demonstrates a unique mixed methods approach to analyzing unstructured qualitative data. It shows how text data can be used to identify measurable market segments for which targeted strategies can be developed.

  • Bizimana, Boumediene
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    A hybrid low - temperature heating system in geothermal retrofitting for public buildings in the Mediterranean climate2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    More than 50 % of EU’s yearly energy demand is spent on heating and cooling systems with which most of its source is generated from non-renewable fossil fuel [1]. Furthermore, half of the EU buildings are heated with a non-efficient boiler of about 60% or less efficiency [1]. The report released by EU from 1990 to 2007 revealed that fuel combustion and fugitive emission contribute to about 79.3% of total greenhouse gas emissions in CO2 equivalents [1]. The EU-EBPD long-term renovation strategy is to improve the energy performance of all residential and non-residential buildings in its member countries through supporting the renovation of the existing buildings into highly energy efficient and decarbonised buildings [2]. Despite all these EU policies and efforts to replace these non-efficient heating systems, the main challenge is price comparison of different solutions and their efficiency in retrofitting of the heating old systems together with the lack of information about the functioning of those old systems [1]. Thus, the development of an easy to install heating system in retrofitting with low exergy heat supply is a significant contribution to a sustainable solution in minimizing energy resources depletion and environmental emission. Furthermore, efficient system control of these easy to install heating systems, hybrids combinations solution for retrofitting building could be a sustainable solution for the preservation of the existing building. The main objective of this work was to design an easy to install hybrid low-temperature floor heating system in retrofitting buildings and compare its results on energy performance, thermal comfort and indoor air quality with other conventional heating mainly used in the Mediterranean climate. This study was performed in two existing radiators heated buildings located in Sant Cugat del vallès in Catalonia, Spain.The results showed that the hybrid low-temperature heating system has the highest energy performance and energy saving of 48 % and 52% compared to that of existing radiator heating and all air heating, respectively. However, hybrid low-temperature floor heating showed a slow heating response, and consequently, it showed lower operative temperature compared to others even though it was within the recommended standards limits. The hybrid low-temperature heating system with demand-controlled ventilation also showed a better indoor air quality, while as existing radiator with its natural ventilation showed the worst indoor air quality. All three compared heating systems showed a better coefficient of performance with low-temperature heat supply and were able to operate with low-temperature heat supply.

     

  • Public defence: 2020-03-27 10:00 K2
    Varini, Maria
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Electrochemical characterization of LiNi1/3Mn1/3Co1/3O2 at different stages of lifetime2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Li-ion batteries have entered our everyday life first as power sources for small electronics, and recently for electric vehicles and stationary storage applications. As the requirements on the performance and lifetime of Li-ion batteries increase and diversify, it becomes paramount to properly understand their electrochemical performance at single-electrode level, and their evolution over cycling. This is crucial for both the design of improved electrode materials, better suited for the most recent applications, but also for accurately predicting the performance decay of existing devices. As the component of focus, the positive electrode was chosen, since it limits both power and energy in Li-ion batteries. Specifically, the material investigated was LiNi1/3Mn1/3Co1/3O2 (NMC111), a state-of-the-art, fully commercial electrode, as well as the precursor for Nirich LiNixMnyCo1 –x –yO2, towards which research is very active. Starting at Beginning of Life, NMC111 was characterized though a combination of electrochemical techniques at varying temperatures (Constant Current cycling, Cyclic Voltammetry, Galvanostatic Intermittent Titration Technique, and Electrochemical Impedance Spectroscopy), which were compared and discussed in terms of electrode response and suitability. Thermodynamic and dynamic properties were obtained, and supported the design of a semi-empirical model for predicting LIBs voltage characteristics. This knowledge was also used to monitor the evolution of NMC111’s performance under high voltage operation, and the possibility of connecting changes in the electrochemical response to specific ageing phenomena: this information could support the creation of physics-based predictive models.

  • Larsson, Filip
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Product and Service Design.
    Floating Tripod: An accessory for people who love documenting their sport adventures2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    People practicing any kind of water sport often owns a GoPro to capture moments of themselves but the accessories on the market today is not enough. This project started with a kitesurfer who wanted pictures of himself while kitesurfing but found out that there are no good accessories for the GoPro that solve this task. The first idea of a floating accessory developed into a real project with the aim to solve this problem. First of all the needs of the customer was examined together with a great amount of research in the area maritime engineering. Co-creation has been important and throughout the project surfers, photographers and engineers have been involved both to fulfill the needs of the customer as well as to solve complex technical problems. During the ideation phase many concepts were generated, evaluated and developed further. Later in the process prototypes were needed to explore the parameters that affected the construction. Several prototypes were made and some were tested in the Indian Ocean while others were tested in a water park. When it was proven what parameters that affected the buoy the most, a final prototype was designed, built, tested and evaluated. In contrast to previous prototypes this one was first carefully designed in CAD and the buoyancy force was determined to check floatability. Thereafter it was 3D-printed and constructed in a more professional way. The result of this project was a final prototype that fulfilled the needs of the customer as well as technical requirements set in the early stages. Summarised, the final solution combines the characteristics of a common sailboat and a cataraman to manage big waves and provide the user with a stable footage. Moreover this is an accessory for people who love documenting their sport adventures and want to share the moments.

  • Harrucksteiner, Alexander
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Development of a GIS-based multiprocessing modelling approach for assessing the wind and solar potential in Mongolia2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Despite the vast wind and solar energy potential, Mongolia is still highly depended on coal-fired electricity generation. At the same time, the pressure on Governments is increased due to the urgency to fight climate change. It is therefore essential to identify the techno-economic wind and solar energy potential of Mongolia, to improve data on its renewable resources. A GIS-based multiprocessing modelling approach for renewable energy site suitability is developed, to incorporate physical-geographical constraints such as slope and socio-geographical constraints such as buffer distances to settlements into the potential calculation. Subsequently, an energy system model named Enertile, developed by Fraunhofer ISI, is used to calculate the techno-economic potential, based on the LCOE method. Final economic interpretations are made in Excel and Python, using the NPV approach. The results support statements by earlier studies, that Mongolia has vast domestic wind and solar resources. The total technical wind and solar potential is estimated at 7.25 TW capacity and 12.17 PWh/year of electricity. The study also reveals, that electricity from ground-mounted PV is the cheapest renewable source and can generate electricity at a very competitive LCOE starting at 48.6 $/MWh. However, due to a very low regulated electricity rate, all renewable technologies still require a Feed-in Tariff. The detailed results showed an economic wind potential capacity of 1.15 GW (3.05 TWh/year). Least cost locations for wind farms are found in the south of the country and could generate electricity at a LCOE of 70 $/MWh (185.5 MNT/kWh). The total economic potential of for ground-mounted PV was 5.12 TW (9.57 PWh/year). Highest solar irradiation locations can generate electricity starting at a LCOE of 48.6 $/MWh (127.9 MNT/kWh). The analysis of rooftop PV showed a 1.11 TW (1.92 TWh/year) economic potential. Rooftop solar PV systems installed at locations with the best solar irradiation, generate electricity at a LCOE starting at 69.8 $/MWh (183.7 MNT/kWh). The ground-mounted and rooftop PV results indicate, that the current FiT support scheme is oversized. Hence, a revision of the Feed-in Tariff support scheme for solar photovoltaic systems is proposed and an adjusted FiT rate is calculated. In case of ground-mounted PV, a FiT adjustment between 58.4 $/MWh and 85 $/MWh should be made in order for Mongolia to reach its 2030 renewable targets. In case of a full decarbonization of the electricity system, a FiT adjustment between 58.9 $/MWh and 85.7 $/MWh is recommended. In order to promote the installation of rooftop PV systems in the capital Ulaanbaatar, a FiT in the range of 108.1 to 147.8 $/MWh is required. In conclusion, this study recommends further promoting the renewable energy technologies, especially utility scale PV, which are available at a comparatively low LCOE, enhance environmental sustainability and increase energy security for Mongolia.

  • Kearns, Kayla
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    The Effects of Sensor Fusion on Localisation in a Sparse, Outdoor Environment2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis compares the results of a localisation algorithm for a mobile robot in both a sparse and a densely featured environment whilst varying key parameters. The software and hardware required to enable the mobile robot to localise itself in the sparsely featured, GPS-denied, outdoor environment is described. The project included a rebuild of a robot built in a previous project, however some hardware was retained. The localisation algorithm was an Extended Kalman Filter fused LeGO-LOAM Simultaneous Localisation and Mapping (SLAM) algorithm with wheel odometry and IMU data. The sensors used for localisation and physical robot parameters (speed and robot weight) were varied to test the localisation performance. Contrary to the projects hypothesis, the smallest error in the sparse environment was from the wheel odometry alone and the second smallest error in the dense environment was the LeGO-LOAM algorithm output. The smallest error in the dense environment behaved as expected at low speeds, with high payload and all sensors, however this test had the largest variance between test cases, therefore may be an outlier. The results show that in both the sparse and the dense environment the larger the velocity the larger the error. Recommendations for further development on this thesis topic are included.

  • Danielsson, Anna
    et al.
    Uppsala universitet.
    Engström, Susanne
    KTH, School of Education and Communication in Engineering Science (ECE), Learning, Learning in Engineering Sciences.
    Norström, Per
    KTH, School of Education and Communication in Engineering Science (ECE), Learning, Learning in Engineering Sciences.
    The Making of Contemporary Physicists: Figured Worldsin the University Quantum Mechanics Classroom2020In: Research in science education, ISSN 0157-244X, E-ISSN 1573-1898Article in journal (Refereed)
  • Grisell, Bengt
    KTH.
    Regalskeppet Kronan: Undervattenstekniken 1979 – 19912020Book (Other academic)
    Abstract [sv]

    Föreliggande text har som syfte att visa på flera olika tekniska tillämpningarsom har använts i projektet Kronan. Några av dessa kan betraktas som nya ochinnovativa och förtjänas att mer ingående beskrivas. Jag tänker då närmast påfärgkorrigering på större djup, metallgaslamporna samt den professionellaIkegamikameran. Alla dessa har tidigare aldrig använts under vatten, vad jagkänner till. Man kan nog påstå att de tekniska tillämpningarna tillfört projektetmycket konstruktivt tekniskt tänkande Man får dock inte bortse ifrån atttekniken gjort betydande framsteg under de 40 år som gått sedan projektetpåbörjades varför denna uppsats delvis kan betraktas som teknikhistoria. Som ettbra exempel kan nämnas utvecklingen av den digitala kameran.

  • Miloševiç, Jezdimir
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Teixeira, André
    Tanaka, Takashi
    Johansson, Karl H.
    Sandberg, Henrik
    KTH.
    Security Measure Allocation for Industrial Control Systems: Exploiting Systematic Search Techniques and Submodularity2018In: International Journal of Robust and Nonlinear Control, ISSN 1049-8923, E-ISSN 1099-1239Article in journal (Refereed)
    Abstract [en]

    To protect industrial control systems from cyberattacks, multiple layers of security measures need to be allocated to prevent critical security vulnerabilities. However, both finding the critical vulnerabilities and then allocating security measures in a cost‐efficient way become challenging when the number of vulnerabilities and measures is large. This paper proposes a framework that can be used once this is the case. In our framework, the attacker exploits security vulnerabilities to gain control over some of the sensors and actuators. The critical vulnerabilities are those that are not complex to exploit and can lead to a large impact on the physical world through the compromised sensors and actuators. To find these vulnerabilities efficiently, we propose an algorithm that uses the nondecreasing properties of the impact and complexity functions and properties of the security measure allocation problem to speed up the search. Once the critical vulnerabilities are located, the security measure allocation problem reduces to an integer linear program. Since integer linear programs are NP‐hard in general, we reformulate this problem as a problem of minimizing a linear set function subject to a submodular constraint. A polynomial time greedy algorithm can then be applied to obtain a solution with guaranteed approximation bound. The applicability of our framework is demonstrated on a control system used for regulation of temperature within a building.

  • Everitt, Carl-Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    Alfredsson, Bo
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    Vrček, Aleks
    Experimental and numerical investigation of asperities and indents with respect to rolling contact fatigue2020Report (Other academic)
    Abstract [en]

    Rolling contact experiments with slip were performed of artificial asperities and indents with pile-up. Micro-pits arose on the leading edge of the asperities and classic rolling contact fatigue (RCF) cracks initiated behind the trailing edge of the indents. The elastic-plastic run-in process and the thermal elastohydrodynamic lubrication (TEHL) load cycles were studied numerically. The run-in process caused high tensile residual stresses on the leading edges of the asperities while the TEHL load cycle caused high tensile stresses on the trailing edges of both the asperities and the indents. The conclusion was thus drawn that the classic RCF cracks behind the indents were caused by the THEL load cycle while the micro-pits on the asperities were caused by the residual stresses.

  • Everitt, Carl-Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    Alfredsson, Bo
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    Öberg, Martin
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Vehicle Engineering and Solid Mechanics, Solid Mechanics.
    An imprint method to produce surface asperities for EHL and RCF experiments2020Report (Other academic)
    Abstract [en]

    A method was developed for creating single well defined surface asperities using an imprint technique. The proposed method can be used to create asperities of different heights and widths in the micrometre range. The technique for creating single surface asperities is based on rolling a hard disc with indents against a soft disc. The contact pressure will cause plastic deformation forcing material into the indents to create the asperities. The height of the asperities can be controlled by adjusting the applied force. After initial reshaping during the run-in process, the asperities were strong enough to survive more than 35 million EHL contact cycles. The method should thus be of great interest for the researchers investigating rolling contact fatigue experimentally. The method could also aid the research of the run in process by enabling tracing the development of specific surface defects. Since the method can produce high and strong asperities it might also prove useful for investigations of exactly how asperities deform under sever contacts conditions.  

  • Everitt, Carl-Magnus
    et al.
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    Alfredsson, Bo
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
    The influence of gear surface roughness on rolling contact fatigue under TEHL conditions with slip2020Report (Other academic)
    Abstract [en]

    Measured shot peened, ground and worn surfaces were included in thermal elastohydrodynamic lubrication and fatigue simulations. Considering transient temperature fields, shear limit and metal to metal contact, moderate negative slip was found to be more detrimental than positive. The location of pitting in gears was thus explained by the surface roughness and the slide to roll ratio. The λ -ratio correlated with fatigue risk within each surface structure. As a supplement to the λ -ratio the surface skewness qualitatively ranked the fatigue risk between the surface structures. 

  • Ekener, Elisabeth
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Katzeff, Cecilia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Strategic Sustainability Studies.
    Gunnarsson-Östling, Ulrika
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Skånberg, Kristian
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Strategic Sustainability Studies.
    Så hänger jämställdhet och jämlikhet ihop med miljömålen: En analys av ömsesidiga beroenden mellan olika Hållbarhetsmål2018Report (Other academic)
  • Yifru Woldemariam, Biramo
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Optimization of Distributed Cooling and Cold Storage in Sweden: Case Study - Norrenergi AB2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    District cooling supply is vital for service, commercial and industrial sectors like hospitals, data centers, supermarkets and sensitive laboratory facilities. The main cooling demand in the case of Sweden also originates from these sectors. The cooling demand in Stockholm is expanding mainly because of demand for comfort cooling, and data centers are rising. To cover the existing cooling demand and rising cooling demand, different cooling strategies have to be employed for optimal production of cold. This project concerns the optimization of such a district cooling system with primarily cold storage. This is achieved by choosing a case study network, namely considering the district cooling network of Norrenergi AB, in Sweden. Norrenergi AB is a company involved in supplying district cooling for cold consumers situated around Solna and Sundbyberg regions. The company provides around 70 GWh district cooling per year. The sources for the district cooling supply are free cooling, electrically driven chillers, and cold recovery from heat pumps. Besides these cold sources, currently, the parts of the peak cold demand are shaved using cold storage that is more cost-effectively charged during night-time, adopting the concept of power-to-cold. In running the district cooling system operation, Norrenergi AB’s current electricity mix is 100% renewable.

    In this thesis work, the existing district cooling network of Norrenergi AB is modeled using BoFiT optimization software (which is the base scenario), and then four future scenarios are developed, considering new, additional cold storages. The scenarios developed were meant to further optimize the existing district cooling grid to cater to the same existing total demand. This is assessed by integrating respective cold storages having larger (i.e., 15 MW capacity) or smaller (i.e., two cold storages each with 3 MW capacity) into the existing district cooling grid. The 15 MW capacity cold storage is integrated into Sundbybergsverket (Scenario 1) and in Frösundaverket (Scenario 2). While, from the smaller cold storages, the first one is integrated into the system in a manner that it supplies cooling for selected cooling customers, that is Scenario 3. The second small cold storage integrated in a way that supplies cooling to the entire grid, which is Scenario 4. Similar to the existing cold storage, in developed scenarios as well, the power-to-cold concept is utilized by charging the cold storage during the time in which the electricity price is lower (i.e., at night). The key outcome of this thesis work reveals that all the developed scenarios lead to cost savings in terms of the consumed electricity for producing DC. The achieved cost saving from each of the four scenarios developed are 23%, 4%, 13%, and 14%, respectively. Among all these scenarios, the first scenario has led to the largest cutback of DC production cost and impliesthat incorporating larger cold storages in cooling production plants results in higher savings. A performed sensitivity analysis also implies that increasing the supply capacity of free cooling results in production cost savings. Besides, an increased cooling capacity by 30% with respect to the base scenario results in a 10.6% cost saving. This saving infers that it is good to utilize free cooling as far as there is an opportunity to increase the use of free cooling.

  • Ghorbani, Morteza
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Svagan, Anna Justina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Grishenkov, Dmitry
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Targeted Hydrodynamic Cavitating Flows via Ultrasound Waves via Pickering Stabilized Perfluorodroplets2020Conference paper (Refereed)
  • Abbasiasl, Taher
    et al.
    Sabanci University.
    Niazi, Soroush
    Sabanci University.
    Sheibani Aghdam, Araz
    Sabanci University.
    Chen, Hongjian
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Cebeci, Fevzi Cakmak
    Sabanci University.
    Ghorbani, Morteza
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging. 1 Sabanci University Nanotechnology Research and Application Center, 34956 Tuzla, Istanbul, Turkey; Faculty of Engineering and Natural Science, Sabanci University, 34956 Tuzla, Istanbul, Turkey.
    Grishenkov, Dmitry
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Kosar, Ali
    Sabanci University.
    Effect of intensified cavitation using poly (vinyl alcohol) microbubbles on spray atomization characteristics in microscale2020In: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226, Vol. 10, no 2Article in journal (Refereed)
    Abstract [en]

    In this study, cavitating flows inside a transparent cylindrical nozzle with an inner diameter of 0.9 mm were visualized, and the effect of cavitation on atomization characteristics of emerging sprays was investigated. Different patterns of cavitating flows inside the nozzle were visualized using a high-speed camera. In-house codes were developed to process the captured images to study the droplet size distribution and droplet velocity in different flow regimes. The results show that cavitating flows at the microscale have significant effects on atomization characteristics of the spray. Two working fluids, namely, water and poly(vinyl alcohol) microbubble (PVA MB) suspension, were employed. Accordingly, the injection pressures were detected as 690 kPa, 1035 kPa, and 1725 kPa for cavitation inception, supercavitation, and hydraulic flip flow regimes in the case of water, respectively. The corresponding pressures for the aforementioned patterns for PVA MB suspension were 590 kPa, 760 kPa, and 1070 kPa, respectively. At the microscale, as a result of a higher volume fraction of cavitation bubbles inside the nozzle, there is no large difference between the cavitation numbers corresponding to cavitating and hydraulic flip flows. Although the percentage of droplets with diameters smaller than 200 μm was roughly the same for both cases of water and PVA MB suspension, the Sauter mean diameter was considerably lower in the case of PVA MBs. Moreover, higher droplet velocities were achieved in the case of PVA MBs at lower injection pressures.

  • Xie, Yiping
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Bore, Nils
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Folkesson, John
    KTH, Superseded Departments (pre-2005), Numerical Analysis and Computer Science, NADA. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL.
    Inferring Depth Contours from Sidescan Sonar using Convolutional Neural Nets2020In: IET radar, sonar & navigation, ISSN 1751-8784, E-ISSN 1751-8792, Vol. 14, no 2, p. 328-334Article in journal (Refereed)
    Abstract [en]

    Sidescan sonar images are 2D representations of the seabed. The pixel location encodes distance from the sonar and along track coordinate. Thus one dimension is lacking for generating bathymetric maps from sidescan. The intensities of the return signals do, however, contain some information about this missing dimension. Just as shading gives clues to depth in camera images, these intensities can be used to estimate bathymetric profiles. The authors investigate the feasibility of using data driven methods to do this estimation. They include quantitative evaluations of two pixel-to-pixel convolutional neural networks trained as standard regression networks and using conditional generative adversarial network loss functions. Some interesting conclusions are presented as to when to use each training method.

  • Malm, Richard
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Hellgren, Rikard
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Enzell, Jonas
    Lessons Learned Regarding Cracking of a Concrete Arch Dam Due to Seasonal Temperature Variations2020In: Infrastructures, Vol. 5, no 2, article id 19Article in journal (Refereed)
    Abstract [en]

    Dams located in cold areas are subjected to large seasonal temperature variations and many concrete dams have cracked as a result. In the 14th International Commission on Large Dams (ICOLD) Benchmark Workshop, a case study was presented where contributors should predict the cracking and displacements due to seasonal variations. In this paper, the conclusions from this case study are presented. Overall, the results from the contributors are well in line with the observations that can be made on the dam and the measurements performed. This shows that using non-linear numerical models is a suitable tool to accurately predict cracking and estimate the displacements of cracked dams. This case study also highlighted important aspects that need special consideration in order to obtain realistic results that can be used to predict the crack pattern, these being: (1) the importance of performing transient thermal analyses based on robin boundary conditions; (2) the influence of contact formulation between the concrete dam and the foundation; and (3) the use of realistic non-linear material properties. The results and conclusions presented in this paper constitute one important step in achieving best practices to estimate dam safety and better understand the potential failure modes and ageing of concrete dams.

  • Gårdeman, Charles
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Cultural Beacon2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The project aims to elevate Halmstad’s historical and contemporary culture. Today, the artistic practice is conducted in separate and closed of cultural clusters. By givning the city a new addition, the Cultural Beacon, the project aims to work in two ways. The first is “to be seen”, in order to attract people of Halmstad to engage and practice its culture. The second is “to show”, in order to illuminate what already is there, and to build upon the resources in the existing cultural clusters. By doing so, the new addition does not only nurture the practice of the city’s culture, but even more important, it nurtures the exchange of culture both between individuals and the collectives, in order to create a more open and inviting city for its residents and visitors to take in. The program of the building consists of three parts. The maker space (to engage the city’s residents in cultural activities), the workers space (to support the existing cultural clusters with space for producing and rehearsing) and the exhibition space (to showcase the story of the city’s culture). These work both separately and collectively in order to link different groups of people and encourage exchange of culture. 

  • Hillebrant, Nadine
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Elevating the shoreline of Ekerö Centrum2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    What would happen if the outskirts and endings of our towns receive the same affection as their cores? This diploma project will tend to one of these forgotten sites. The shoreline of Ekerö Centrum - A site longing for identity, to become more than it is today. The park by this shoreline, which unintentionally has become the back end of the town center, has the potential to be elevated into a key node for Ekerö. This project looks to the existing assets of the site - it’s water contact, the view over the fields and forests of Lovön and the connection to Stockholm City via commuter boat, and suggests three additions to the site to activate it and let people enjoy these elements. By looking closer at the site three different points spread out in the park was identified. These points each received an addition. The first - a waiting hall for the boat station. Second,a marketplace - which essentially is a piece of park furniture that can be used in multiple ways. And third - a sauna to experience the water.

  • Frisk, Emelie
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Fantasifabriken2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A silo building in Vadstena in south of Sweden from 1956 is abandoned and no longer in use. The context of the building is quite interesting since it is placed in the middle of the town next to one of Swedens most well preserved renaissance castles and the harbor. My project is about this silo, how to find a new program and function for it. And also look att the surroundings how the municipality should try to change some parts of the city plan to better fit their own visions and strive for a more sustainable development. My suggestion for the new program is an art hall with a creative studio part that could be available for everyone in the area. It would provide a space that seems missing and that would be appreciated by many non established artists in the area that have no where to meet, work and have exhibitions. That would also be a sustainable way of taking care of an building that is no longer in use.

  • Hwasser, Martin
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Converting Deterministic Simulators to Realistic Stochastic Models via Data Alignment2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Simulation is commonly used to train agents in Reinforcement Learning since they provide an abundance of data that in many cases can be generated faster than real-time. However, the behaviors learned by the agent are often specific to attributes of the simulator and may not perform well when transferred to the real world. This thesis describes an algorithm that can be used to minimize the discrepancy between simulation and reality. Using this algorithm, it is possible to both identify parameters of the simulator that results in more accurate simulation of reality, and learn a generative model that can produce output that is close to real-world dynamics.

    We first show how this algorithm works on a problem that can be solved analytically. We then demonstrate that the algorithm successfully handles more elaborate environments with physics simulation involving contact between objects and control actions.

  • Cancino, Ana
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Usage of Distributed Systems Data for Automated Financial Health Advice2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Financial health is a subject that deeply affects the choices and decisions one takes everyday, but for most people, financial concepts are difficult to understand. Financial illiteracy worldwide amounts to approximately 67%, and in Sweden, being one of the world’s least financial illiterate countries, it is around 29% [1].

    The goal of this research is to be able to provide more insights into an individual’s financial health situation. During the development, several steps have been taken so as to make a program which will predict the customer’s risk capacity, which means the risk an individual has to take in order to achieve his or her goals. First, a program is developed to map occupations into their closest job titles using NLP, which has to be done so as to be able to use occupations for Data Mining. Then, a case-based recommender system is developed in order to get insights into the customer’s data about the their personal financial situation. Finally, based on the above, using the customer’s profile information and following the CRISP-DM methodology, be able to predict the risk capacity of the customer using Machine Learning and Deep Learning techniques.

  • Martínez Olivo, Alejandro
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Positioning System for Rescuing Missions in Underground Facilities: Wireless Network Implementation2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the case of an emergency in an underground facility, the harsh environment make the rescue missions a difficult and taxing task for the first responders. Disorientation, stress and lack of communication are fatal in that territory. In order to overcome all this difficulties and provide a system to coordinate and help locate emergency responders, a new Indoor Positioning System (IPS) is proposed. The system shall be scalable so it can expand its coverage over the site, it would adapt and remain reliable in the harsh conditions of the environment.

    The main goal of this project is to present an analysis of the current wireless technologies, their advantages and disadvantages and a comparison between them. Build a new solution and present the results of the performance of the network. The tests recreate the characteristics of the underground territory and present a good analysis of the system.

    This thesis project report the process, to build a scalable, adaptable and reliable wireless network to be used as the framework of a positioning system. The system is constructed using the ZigBee protocol stack and the nRF52840 hardware. A graphical user interface is developed to facilitate the configuration of the network. At the end the results gives proof that the system can be used in the underground facilities as long as the network is deployed carefully.

  • Repper, Elias
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    The effect of printing parameters on the deformation and microstructure of Inconel 718: A study in pulsed laser and powder based directed energy deposition additive manufacturing2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Additive manufacturing has the power to redefine how we create components. In order to minimize removal of printed material, deformation must be kept a minimum. When deposition rate is increased during directed energy deposition so is the power requirement for melting the feedstock. This increases the residual stresses in the material and leads to more deformation. The deposition rate must be increased without introducing large deformation, if additive manufacturing is ever to be economical in many engineering fields.

    This study aims to explore if pulsing the laser can decrease deformation using a design of experiments approach. Other types of defects and microstructural changes are also evaluated. A total of 17 sets of parameters were used varying laser power, pulse frequency and the time fraction when the laser was powered on. The amount of powder added to a substrate was constant and the build geometry as similar as possible for all tests.

    Ultimately no conclusion could be drawn regarding pulsing parameters effect on deformation. It was found pulsing the laser lowered the powder efficiency drastically, which may have had a bigger effect on the experimental set up than anticipated. In a similar manner, no relation between pulsing parameters, defects and microstructure could be observed.

  • Neuman, Daniel
    KTH, School of Engineering Sciences (SCI), Physics.
    Classification and identification of neutrons and gamma rays in AGATA detectors using a neural network2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Gilljam, Charles
    KTH, School of Engineering Sciences (SCI), Physics.
    Superconducting domes for a two-band BCS model with nite-range potentials2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Paschen, Jeannette
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Marketing and Entrepreneurship.
    Wilson, Matthew
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Marketing and Entrepreneurship.
    Dias-Ferreira, Joao
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Collaborative intelligence: How human and artificial intelligence create value along the B2B sales funnel2020In: Business Horizons, ISSN 0007-6813, E-ISSN 1873-6068Article in journal (Refereed)
    Abstract [en]

    The B2B sales process is undergoing substantial transformations, fuelled by advances in information and communications technology and specifically by artificial intelligence (AI). The premise of AI is to turn vast amounts of data into information for superior knowledge creation and knowledge management in B2B sales. In doing so, AI can significantly alter the traditional human-centric sales process. In this article, we describe how AI impacts the B2B sales funnel. Specifically, for each stage of the funnel, we describe key sales tasks, explicate the specific contributions that AI can bring and clarify the role that human contributions play at each step of the AI-enabled sales funnel. We also outline managerial considerations to maximize the contributions from AI and people in the context of B2B sales.

  • Paschen, Jeannette
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Marketing and Entrepreneurship.
    Investigating the emotional appeal of fake news using artificial intelligence and human contributions2019In: Journal of Product & Brand Management, ISSN 1061-0421Article in journal (Refereed)
    Abstract [en]

    Purpose:

    The creation and dissemination of fake news can have severe consequences for a company’s brand. Researchers, policymakers and practitioners are eagerly searching for solutions to get us out of the ‘fake news crisis’. Here, one approach is to use automated tools, such as artificial intelligence (AI) algorithms, in conjunction with human inputs to identify fake news. The study in this article demonstrates how AI and machine learning, with its ability to analyze vast amounts of unstructured data, can help us tell apart fake and real news content. Specifically, this study examines if and how the emotional appeal, i.e., sentiment valence and strength of specific emotions, in fake news content differs from that in real news content. This is important to understand, as messages with a strong emotional appeal can influence how content is consumed, processed and shared by consumers. 

     

    Design/methodology/approach:

    The study analyzes a data set of 150 real and fake news articles using an AI application, to test for differences in the emotional appeal in the titles and the text body between fake news and real news content. 

     

    Findings:

    The results suggest that titles are a strong differentiator on emotions between fake and real news and that fake news titles are substantially more negative than real news titles. In addition, the results reveal that the text body of fake news is substantially higher in displaying specific negative emotions, such as disgust and anger, and lower in displaying positive emotions, such as joy. 

     

    Originality/value:

    This is the first empirical study that examines the emotional appeal of fake and real news content with respect to the prevalence and strength of specific emotion dimensions, thus adding to the literature on fake news identification and marketing communications. In addition, this paper provides marketing communications professionals with a practical approach to identify fake news using AI.

  • Paschen, Jeannette
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Marketing and Entrepreneurship.
    Wilson, Matthew
    Robson, Karen
    #BuyNothingDay: investigating consumer restraint using hybrid content analysis of Twitter data2020In: European Journal of Marketing, ISSN 0309-0566, E-ISSN 1758-7123, Vol. 54, no 2, p. 327-350Article in journal (Refereed)
    Abstract [en]

    Purpose:

    This study aims to investigate motivations and human values of everyday consumers who participate in the annual day of consumption restraint known as Buy Nothing Day (BND). In addition, this study demonstrates a hybrid content analysis method in which artificial intelligence and human contributions are used in the data analysis.

     

    Design/methodology/approach:

    This research uses a hybrid method of content analysis of a large Twitter data set spanning three years.

     

    Findings:

    Consumer motivations are categorized as relating to consumerism, personal welfare, wastefulness, environment, inequality, anti-capitalism, financial responsibility, financial necessity, health, ethics and resistance to American culture. Of these, consumerism and personal welfare are the most common. Moreover, human values related to “openness to change” and “self-transcendence” were prominent in the BND tweets.

     

    Research limitations/implications:

    This research demonstrates the effectiveness of a hybrid content analysis methodology and uncovers the motivations and human values that average consumers (as opposed to consumer activists) have to restrain their consumption. This research also provides insight for firms wishing to better understand and respond to consumption restraint.

     

    Practical implications:

    This research provides insight for firms wishing to better understand and respond to consumption restraint.

    Originality/value:

    The question of why everyday consumers engage in consumption restraint has received little attention in the scholarly discourse; this research provides insight into “everyday” consumer motivations for engaging in restraint using a hybrid content analysis of a large data set spanning over three years.

  • Annadotter, Kerstin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Werner, Inga Britt
    KTH, School of Architecture and the Built Environment (ABE).
    Arbetsrapport nr 6 i projekt: Grannskapseffekter på områdesnivå-en fördjupad studie av bostadsrättsombildning i allmännyttan2017Report (Other academic)
  • Xue, Han
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Cohousing Community Design2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    My project is a cohousing community in Berlin. Cohousing is an intentional community of private homes clustered around a shared space. In my project, I divided the shared place into two parts, indoor communal and outdoor communal. For indoor communal, I focus on creating communal halls for people living in community. For outdoor communal, I focus on creating multiple courtyards with different characteristics.

  • Jonas, Lisa
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    A prologue to the post coal-mining era2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The surface mine Hambach is located in the west of Germany, close to Cologne and was founded in 1978 from the electric company RWE to dig up brown coal and produce electricity. The mine measures a surface of 8.500ha and a depth of 470 m and was planned to be operated until 2045. After mining RWE plans to recultivate the area with forest, agriculture and a remaining lake of 3900ha. The mine is a site that is out of proportion. This proposal is a composition of interventions in different time and scale aiming to tell the story of soil, water, vegetation, animals and humans. The excavator is a scale figure to these dimensions and becomes the protagonist of the story. On it‘s way down to its final position at the bottom of the pit, it is sculpting the soil one last time. After that last operation nature will take over. Water will find its path and reshape the pattern of the excavator. With water, vegetation comes back and then gives space for animals to live and humans to watch the transition from a colourful desert to a flourishing oasis. This stream of interventions is connecting the pit‘s terraces to a spiral sculpture that over time will fill with water.

  • Forsskåhl, Ellen
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Kvar på Koverhar: En berättelse om återväxt2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the thesis project Residual resource - A story of regeneration the remains of an abandoned steel factory become the breeding ground for sustainable future settlement. Situated on the shore of southern Finland the area of Koverhar is in the midst of the forrest, but exceptionally well-equipped with infrastructural connections to the country's main cities. I have explored an imaginary scenario where future needs are catered to through environmental care, sustainable political decisions, resource-saving productions and decreased consumerism. In my thesis the bioremediation process initiates the expansion of the built environment. The non-urban location of the site makes the slow and ecologically effective bioremediation process ideal - the immediate need for exploitation is low, instead a community is allowed to form over a long period of time, based on soil-treatment and visualized changes in societal ideals concerning habitual urban and rural lifestyles. The existing foundations left at the site after the extensive demolition, will be used to generate unexpected spatial qualities in the built environment. The core of the development will remain public throughout the remediation process, with dwellings influenced by local tradition forming around. Through Residual resource - A story of regeneration I have explored the notion of circularity in terms of both environmental regeneration and architectural  reuse. The future need for reclaiming post-industrial sites and remediation of contaminated environments are but a contemporary challenge a source of potential for reuse of resources and regeneration of ecosystems and rural settlements.

  • Edin, Rebecca
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Constructing Memories2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The project examines, and experiments with, how one can use historical fragments as a starting point for the design of a 7000 square meter large civic center, or house of arts and culture, in Beirut, as this is a place where the urban development has had a very different point of departure the last decades. The historical fragments in this case has been a collection of postcards of various public buildings that existed in the city between 1890 and 1970. Many times postcards are the main record of history of historical places, but this is not the main reason why I chose it as a study object. I chose it because of their purpose; to communicate a story of the place it portrays to outsiders, to people whose only knowledge about that place comes from the image on its front and the restricted number of words that can be squeezed into the small area on the back. Given my position as a foreigner working in a context that, although having visited multiple times, is unfamiliar to me, I found this an interesting starting point for the project.

  • Dahlberg, Jill
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Läkande Arkitektur2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    My thesis project in architecture is all about environmental psychology, with the purpose to investigate the connections between psychology and architecture. A major part of my work has been to study the subject called evidence-based design - the connections between healthcare environments and patients health has been proved. I have studied different written programs for psychiatric buildings and studied several reference projects to come up with a conclusion about several different healing design aspects. With support from this basis I have worked with an excising building -Nyköpings psychiatric clinics, which were originally drawn by ELLT Architects in the late 1960´s. I have studied the excising building, how it works today, after a several renovations and reconstructions. After an analysis of the building, as well as after several meetings and interviews with the staff working there, I have decided to draw an extension. The main purpose with it is to close a central courtyard and make it accessible for the patients to enter whenever they want. I have added functions in the additional building that the staff think is missing and prevents them from manage the type of healthcare they would like to. I have constantly been using the stress reducing design functions there is scientific support for.

  • Muller, Sharon
    Universität Stuttgart, Institut fur Energieubertragung und Hochspannungstechnik.
    Development of Nordic 32 System Model and Performance Analysis Based on Real Operational Statistics2019Report (Other academic)
    Abstract [en]

    In this project the existing Nordic 32 test system was analysed in DIgSilent PowerFactoryand approached to the actual Swedish transmission grid. Focus was the reallocation ofthe load and generation. On one hand, the installed capacity was nearly quadrupled, onthe other hand the geographic location of the plants was considered. Therefore, thefour most important generation types, hydro-, nuclear-, wind and thermal power areincluded into the model. Furthermore, the four electricity areas SE1 - SE4 were adoptedinto the test system and the transnational connection modelled as well.The modified test system allows simulations based on real operation statistics. In thisproject, the complete year 2018 was simulated in an hourly resolution. The stable gridoperation within the given voltage limits were secured by static and dynamic reactivesuppliers. A validation of the active power flows shows the coincidence of the simulationresults and the real operation data of 2018. Hence, the resultant grid model representsthe Swedish transmission grid more accurate and offers plenty of different study cases.Furthermore, it gives the yearly voltage profile for each bus and helps to identify weakand strong regions in the Swedish transmission grid.

  • Haglund, Teodor
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Prediction of Process Parameters for Powder Bed Fusion Using Electron Beam2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Powder Bed Fusion using Electron Beam (PBF-EB) process is a highly complex additive manufacturing process. There are a very limited number of materials that have been used successfully, which limits the applications of the process, despite its well-documented advantages over conventional manufacturing. However, the development of new materials is hindered due to a lack of understanding of the fundamental phenomena in the process. The goal of this work has been to develop a model that is able to predict the process parameters that will lead to the manufacture of a fully dense component.

     

    The model is based on 1285 empirical datasets of process parameters and the physical properties of the printed materials. Nine different materials were included in the data. By inputting a pre-defined set of process parameters and materials properties the model will output the beam power at which it is predicted a dense component may be manufactured. This novel approach will shorten the development of new process parameters by providing a first approximation of suitable parameters to iterate from. A tool steel powder supplied by Uddeholms AB was printed, using parameters proposed by the model. Two sets of pre-defined process parameters were used with several beam velocities and resulted in a number of correct predictions.

     

    This model is a first step in predicting process parameters and presents a simple, transparent and new method of obtaining the process window for novel materials in Powder Bed Fusion using Electron Beam.

  • Public defence: 2020-03-16 10:00 F3, Stockholm
    Chen, Yuanying
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Land-Sea Interactions in the Coastal-Marine System of the Baltic Sea under Hydro-Climatic Variability2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis investigates a few important component processes for understanding and quantifying eutrophication in the Baltic Sea, that include characterization of nutrient loadings from land, water flow in the sea under changing climate conditions and transport of solutes originating from different locations along the coast. Furthermore, this study aims to improve our understanding on how processes from land (the nutrient loading conditions) and the sea (transport dynamics and water quality) couple to determine the fate of nutrients in the sea and the water quality in a selected localized coastal area, the Himmerfjärden Bay.

    Comprehensive data are compiled as a basis for numerical simulations. An open source tool for oceanographic studies FVCOM is used to simulate flow and transport processes in the Baltic Sea. Hydrodynamic simulations are verified in terms of temperature, salinity and water level for the year 2005. Results show that most of the investigated Swedish watersheds along the coastline are dominated by subsurface legacy sources, the loads of which are positively and linearly correlated with river discharges. Moreover, subsurface legacy sources are less likely to decrease over time compared with the current surface sources. The Baltic Sea has a stable flow structure considering flux directions between basins, while the flux magnitudes between basins are mainly determined by different wind conditions. The spreading patterns in the sea with solute released from different coastal areas are similar when the released amounts are comparable, even though different cases have different source input and water flow conditions. The overall spreading patterns in the sea are generally dominated by the total mass of released solute. Local transport dynamics and patterns around the coast differ greatly for different cases and are determined by the local flow conditions. Different water quality indicators are influenced by different land-based or sea-based measures for water quality improvement. The dry-cold hydro-climatic condition is the most favorable for improving the water quality and elevating the ecological status in the Himmerfjärden Bay.

    Based on this investigation, varying hydro-climatic factors impose important influence on the different component processes of nutrient loading from land to the sea. For example, the change of river discharges from land in the future would influence the total load into the sea from subsurface legacy sources, and finally influence the general spreading patterns of nutrients in the sea. The change of wind conditions would affect the flow and transport dynamics at local scale and flow fluxes magnitudes between marine basins at the sea scale. Change towards a dry-cold condition would be beneficial for the water quality and lead to improvement of coastal water quality, while the change towards a wet-warm condition will be generally unfavorable for improving the water quality. Clearly more comprehensive studies are needed based on the component processes considered in this thesis, for mapping water quality and eutrophication long-term trends in the Baltic Sea with confidence that is sufficient for effective mitigation measures and policies. 

  • Public defence: 2020-03-17 10:00 F3, 114 28 Stockholm
    Pinto Basto de Carvalho, Joao Frederico
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Robotics, Perception and Learning, RPL. KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for Autonomous Systems, CAS.
    Topological Methods for Motion Prediction and Caging2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    To fulfill the requirements of automation in unstructured environmentsit will be necessary to endow robots with the ability to plan actions thatcan handle the dynamic nature of changing environments and are robust toperceptual errors. This thesis focuses on the design of algorithms to facilitatemotion planning in human environments and rigid object manipulation.Understanding human motion is a necessary first step to be able to performmotion planning in spaces that are inhabited by humans. Specifically throughlong-term prediction a robot should be able to plan collision-avoiding paths tocarry out whatever tasks are required of it. In this thesis we present a methodto classify motions by clustering paths, together with a method to translatethe resulting clusters into motion patterns that can be used to predict motion.Another challenge of robotics is the manipulation of everyday objects.Even in the realm of rigid objects, safe object-manipulation by either grippersor dexterous robotic hands requires complex physical parameter estimation.Such estimations are often error-prone and misestimations may cause completefailure to execute the desired task. Caging is presented as an alternativeapproach to classical manipulation by employing topological invariants todetermine whether an object is secured with only bounded mobility. Wepresent a method to decide whether a rigid object is in fact caged by a givengrasp or not, relying only on a rough approximation of the object and thegripper.

  • Lindbøl Bjørseth, Henrik
    KTH, School of Electrical Engineering and Computer Science (EECS).
    On the Feasibility of Deploying Highly Resilient Data Plane Forwarding Mechanisms Using Programmable Switches2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Network downtime is costly for providers of information technology services. One cause of network downtime is link failures. The control plane of the network is the entity responsible for ensuring connectivity upon link failures. The data plane of the network forwards packets at line speed and it is controlled by the control plane. One disadvantage of ensuring connectivity at the control plane level is the time needed to react to a failure. The control plane is several orders of magnitude slower than the data plane. Moving the connectivity responsibility to the quicker data plane has therefore the potential to reduce network downtime.

    This work explored what level of connectivity robustness can be achieved when implementing data plane connectivity algorithms in today’s high-speed speed programmable switches. A literature study of several data plane connectivity algorithms was conducted. A critical aspect considered in this study was the simplicity of the data plane connectivity mechanism as high-speed programmable switches cannot support arbitrarily complex forwarding function. Data-Driven Connectivity (DDC) was selected as a suitable algorithm due to its high guaranteed connectivity and algorithmic simplicity.

    DDC was implemented in a virtual network environment using P4 programmable software switches. Our solution automates the generation of the virtual network based on a topology description. It also initializes the switches and generates the specific DDC P4 code for each switch. All the functions of DDC P4 have been tested to verify that each function behaved as expected. The path optimality of DDC P4 after several link failures were evaluated on the emulated Google’s wide area network topology, called B4 (2011). The path optimality evaluation shows that the path stretch of DDC P4, i.e., the gap from the shortest path in the number of hops, is not optimal for about 30% of the possible source/destination node pairs in the topology. The throughput of the DDC P4 was also evaluated along different number of link failures. The throughput results show a linear decrease in steps of 0.4 Mbps depending on which outbound link was utilized, starting from a throughput of 6.3 Mbps in the absence of failures.

    The current DDC P4 implementation does not scale well due to duplicate code for each destination in the topology. Both improving the scalability of the current implementation and an implementation on a hardware programmable switch remain as future work.

  • Ruan, Yifan
    KTH, School of Electrical Engineering and Computer Science (EECS).
    A Co-Simulation Framework for Black-box Testing of In-Vehicle ECUs2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the increasing complexity of embedded systems in the automobile industry, the demand on the testing process increases simultaneously. Bus communication behavior is an important feature which is used by testers to evaluate functions of the embedded system under test. However, the existing testing method Hardware-in-the-Loop simulation is expensive and it is mainly used at the late stage of the project life cycle. Additionally, the time and resources available for the testing process are very limited.

    The thesis designs a co-simulation framework for testing functions of invehicle Electronic Control Units (ECUs). It is dedicated to providing a realistic environment for the ECU under test at both early and late stages of the project life cycle and reducing the cost of the testing process. The framework consists of multiple ECUs that are implemented by different methods and connected to the same vehicle bus. A prototype is also implemented to evaluate the design of the co-simulation framework. Multiple simulation tools are used during the process of the prototype implementation. Limitations and future work of the thesis are discussed.

    As a proof-of-concept framework, the resulting prototype can be extended to more functions and provides solutions for further research on ECU testing.

  • Vijayendra Walvekar, Patrik
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Virtualizing LoRa baseband functionalities to the Edge2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Traditional network architecture design of Low Power Wide Area Networks (LPWAN) suffer from their inability to dynamically scale resources based on the incoming traffic and involve manual procedures for capacity upgrades. There is a need to develop a cloud-native architecture where the gateway hardware performs signal detection while baseband processing is virtualized in the Edge, provisioning for dynamic scaling of resources. Cloud Radio Access Network (CRAN) as a concept can be leveraged to realize such a functional split architecture.

    In this thesis work, a LoRa based IoT Radio Access Technology (RAT) system is developed in a cloud-native design where the physical baseband processing is pushed to an Edge computing system. The open source GNURadio software environment is used to prototype the split-architecture design. A preamble detection method is implemented on the gateway, also called the Radiohead (RH), to identify and transmit only the LoRa based packets, which reduces the Fronthaul (FH) link utilization. Our study shows that the proposed split-architecture is feasible with a performance on-par with traditional architecture. The proposed system can operate in all the 3 mandatory channels of EU868 band as specified in the LoRa standard. Measurement results like CPU utilization and network capacity usage, from integration with IEEE 802.15.4 and NB-IoT stacks, further show the feasibility of the multi-RAT scenario. Additionally, implementation comparisons of C++ and Python showed C++ as a better choice for developing modules in the GNURadio environment. Finally, insights were shared into further developing this work like focussing on the drawbacks related to multi-Spreading Factor detection on same channel and interfacing with higher layer open-source architectures like The Things Network.