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  • Martin, Michael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    The Effect of Geometrical Contact Input to Wheel-Rail Contact Model2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Wheel-rail contact is an important aspect of railway, the forces transferred between the wheel and rail are the one that guide, brake, or accelerate the train, and that is why the understanding of the contact between wheel and rail is an interesting research topic. In this master thesis wheel-rail contact model named ANALYN is used to see the effect of the different geometrical input, like undeformed distance, relative longitudinal curvature, and relative lateral curvature calculation affect the contact patch estimation formed at the wheel-rail contact. 

    In the process, a geometrical contact search code is made to find the contact point between wheel and rail for certain lateral displacement, yaw angle, and roll angle of the wheelset. The codes used to calculate the three geometrical inputs are also prepared, with two methods are prepared for each input. The results that generated from combination of the geometrical contact search and geometrical input preparation are used as the input to ANALYN.

    The results showed that different geometrical input calculations do affect the shape of the contact patch, with the calculation of lateral curvature being the most important since it affects the shape of the contact patch greater than other geometrical inputs. It is also shown that taking yaw angle into account in the contact search will affect the shape of the contact patch.

  • Sinha Roy, Arijit
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Analysis and control of boundary layer transition on a NACA 0008 wing profile2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main aim of this thesis was to understand the mechanism behind the classical transition scenario inside the boundary layer over an airfoil and eventually attempting to control this transition utilizing passive devices for transition delay. The initial objective of analyzing the transition phenomenon based on TS wave disturbance growth was conducted at 90 Hz using LDV and CTA measurement techniques at two different angles of attack. This was combined with the studies performed on two other frequencies of 100 and 110 Hz, in order to witness its impact on the neutral stability curve behavior. The challenges faced in the next phase of the thesis while trying to control the transition location, was to understand and encompass the effect of adverse pressure gradient before setting up the passive control devices, which in this case was miniature vortex generators. Consequently, several attempts were made to optimize the parameters of the miniature vortex generators depending upon the streak strength and stability. Finally, for 90 Hz a configuration of miniature vortex generators have been found to successfully stabilize the TS wave disturbances below a certain forcing amplitude, which also led to transition delay.

  • Ertan, Joakim
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Digital Readiness of Swedish Organizations2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper tries to measure the level of digital transformation among Swedish organizations. This is done through utilizing a maturity model and collecting data through an online questionnaire from 21 different organizations and measuring their digital readiness. The result seem to indicate that Swedish organizations have a been affected by digital transformation and have a slightly lower level of digitalization than foreign organizations.

  • Davidsson, Sophie
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    A Framework for the Evaluation of Technologies during the Implementation of Digitalisation Strategies in the Asset Management Industry: A study on new technology adoption within the asset management industry2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The financial industry is currently undergoing radical change as a result of the increased implementation of digitalisation strategies. Due to pressure from a number of sources, finance firms, including asset managers, are looking to adopt technology solutions in their business processes. Through the introduction of new technologies and digitalisation strategies, the asset managers are hoping to secure their market segments in the future. Choosing which technology to implement is considered one of the most difficult decisions a manager has to make. Hence, this thesis proposes a framework to be used by asset managers in order to efficiently and swiftly evaluate a number of technologies when looking to digitalize manual processes.

    The largest bank in the Nordic region is Nordea, who have just recently announced that they will be looking to implement more digital solutions. This thesis was conducted in collaboration with Nordea Asset Management.

    The thesis explores three core areas: the future of the asset management industry, digitalisation strategies, and new technology adoption in order to produce the analytical framework. The framework is constructed using previously explored methods described in literature along with the key information gathered from experts at Nordea Asset Management. The result is a framework which combines expert knowledge of the asset management industry, successful methods regarding conceptual frameworks, technology life cycle and new technology adoption theory and digitalisation strategy concepts.

    In order for traditional asset managers to maintain their market position they will need to adapt new technologies. This is not only needed for efficiency and cost reasons but also because customers are starting to demand it. The sales channels, operations, personnel requirements and the business model as a whole are areas identified by this research project that will adapt through the introduction of digitalisation strategies being introduced. The framework constructed in this thesis provides the asset management firms with a method of successfully applying digitalisation strategies through new technology adoption.

  • DE VRIES, MARTE
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Speeding Up Social Entrepreneurship: Improving the Sustainability of the Accelerator Program2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the past decade, a new entrepreneurial phenomenon aimed at seeding start-up companies has emerged across the globe: the social enterprise (SE) accelerator program. These accelerators focus on scaling social entrepreneurs by accelerating their journey to the market. Different actors like business reporters, entrepreneurs, and angel investors have expressed skepticism around the viability of the accelerator model. To research this sustainability, this thesis studied the revenue models of SE accelerators. Four semi-structured interviews were conducted with experts working at SE accelerators in Stockholm. These four identified getting revenue from partnerships, government institutions, and philanthropy and donations. Consulting contracts, equity shares and fees were not used by these four but were discussed as potential revenue streams. All respondents emphasized the importance of revenue model diversification and were currently working on strategies to act on this. Diversifying the revenue models of SE accelerators will increase the sustainability of their revenue models. This might be the first step from the focus of monetary gain towards a society where business is created to do good.

  • Blomqvist, Ludvig
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Blockchain and Entrepreneurial Value Creation in the Textile Industry2018Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis examines a process of innovation within a Swedish early-stage start-up company in the textile industry. The thesis describes and analyzes the case company’s intentions to create entrepreneurial value by reconfiguring its supply chain as one of its resources. Theories of dynamic capabilities, entrepreneurial value creation and supply chain management are applied for analysis of the case company’s process of investigating how Blockchain technology can be applied to the company’s supply chain to create and enhance value for the company, its customers and suppliers. Topics of digitalization, Blockchain technology, supply chain management, entrepreneurial value creation and dynamic capabilities are covered as part of the discourse.

    The work in this thesis is qualitative and explorative and based on the study of one case company and its quest for creating entrepreneurial value by reconfiguring its supply chain. The study explores several potential ways for how entrepreneurial value can be created through process of innovation, e.g., by the application of Blockchain to a company’s supply chain.

    Although Blockchain has potential to create entrepreneurial value for the case company, it is not possible to predict if the benefits outweigh the costs, if the project is feasible in practice, if it is suitable for one company to undertake the project on its own or if collaboration and alliances are the way forward.

  • DRAGON, ERICA
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    TAFLIN, JOHANNA
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Factors Influencing the E-commerce Purchase Process of Big High Involvement Products2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    E-commerce is growing and has grown considerably during the last two decades. It is also growing within product segments previously believed to be hard to sell over the internet, such as big high involvement products and this is calling for an exploration of the e-commerce purchase process for this product segment. The e-commerce channel is associated with various benefits and barriers and with sufficient trust these barriers can be overcome. This study therefore explores the e-commerce purchase process of big high involvement products from a customer perspective identifying key benefits and barriers together with factors contributing to trust formation and customer retention. This combines areas of research, not previously explored. The results are based on focus group interviews and reveal that the main benefits perceived were a lower price, easier comparison between options and a bigger product range. The main risks for this product segment seem to be performance risk and financial risk together with the risk of low delivery precision. Main factors contributing to trust were good return policies, good information quality and guiding together with affect-based factors such as recommendations from a friend. Finally, the factors identified in this study to contribute to customer retention were customer satisfaction, after sales services and something “extra” upon delivery. The results confirm some of the previous evidence, such as Venkatraman (1989), saying that high involvement products are coupled with higher risks, but it also finds new suggestions to important factors such as delivery precision and something “extra” upon delivery that may be specific to this product segment.

  • ULINDER, MARTIN
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    The rise of private equity in Asia: Is it hampered by perceived corruption?2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis examines the relationship between private equity activity and perceived corruption in Asian countries controlling for many different economic factors. The study finds indications that perceived corruption negatively affects private equity in Asia, however this is not statistically proven for all countries. When analysing groups of countries separately, the study finds that higher perceived corruption is positively correlated with private equity activity in Developed markets but negatively correlated with private equity activity in Emerging markets. For Frontier markets, the relationship is not statistically significant, even though indications point to a negative relationship. The ability to enforce contracts, measuring the quality of judicial systems, is the most significant determinant of private equity activity. Furthermore, the paper finds that control variables overall have bigger effects for emerging and frontier countries than for developed economies, implying that richer economies already have higher levels of economic development and small changes do not have much impact, but for poorer countries, smaller changes in different factors seem to boost private equity activity

  • ÖBERG, JENNY
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    STENLÖF, ELIN
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    What role to play in strategy implementation?: Constructive interplay between middle and frontline managers2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Purpose: The purpose of this research was to study the interplay between middle managers (MMs) and front-line managers (FLMs) in strategy implementation (SI). To successfully manage and run a complex technology corporation a well-performed strategy is essential. By comparing MMs’ and FLMs’ different views and responsibilities in the SI process, both theoretical and empirical. Methodology: Theoretical material regarding leadership, middle and front-line manager roles and responsibilities, as well the strategy implementation process, obstacles and success factors are compared in the study. Supplemented by a general pilot study and primary interviews covering their view of the SI-process, obstacles and leverages, leadership, and their roles description. In total, ten pilot interviews and 12 primary interviews have been conducted, with MMs and FLMs, equally represented. Findings: In large, the main findings regarding the creation of a dynamic interplay between MMs and FLMs were three identified key attributes. Firstly, success in the SI process and constructive dynamic require a clear distribution of tasks and responsibilities between MMs and FLMs or the key responsibilities in the process. Secondly, select key people for the SI process, picked from different levels in the organization with different viewpoint and expertise. Making sure that there are total transparency and knowledge sharing between all key members and organizational levels. This will enable a greater involvement and commitment in the SI-process. Finally, to create a successful SI-process and a dynamic interplay between MMs and FLMs, strategic work must be rewarded equally compared to operational excellence and product-development efforts.

  • SUNDQVIST, ALYCIA
    KTH, School of Industrial Engineering and Management (ITM).
    A company’s ability Not to default on a loan: Does the location have an impact?2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis aims to answer the question if the type of region or category of a municipality in which a company is located in, impacts the company’s ability not to default on a loan. Previous literature is used to find which determinants have an impact on a company’s survival from five levels: Macro, Industry, Regional, Company and Individual entrepreneur. The data used is in collaboration with a financial company offering small businesses credit products. They have contributed with loan data. A statistical analysis has been done and the method used is a logistic regression, where the dependent variable is if the company is defaulting on their loan or not. The conclusions that can be drawn are that in correlation with the previous findings the age of the firm, employees, and capital had a positive relationship to a company’s probability of not defaulting. Furthermore, the regional factors does have an impact on a company’s ability not to default on a loan. The commuting regions have a positive relationship to the probability of a company’s ability not to default on a loan.

  • Public defence: 2018-12-20 14:00 FA31, Stockholm
    Manickam, Louis
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Power Safety.
    An Experimental Study on Melt Fragmentation, Oxidation and Steam Explosion during Fuel Coolant Interactions2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nordic type boiling water reactors (BWRs) adopt reactor cavity flooding as a severe accident mitigation strategy (SAMS) to achieve core melt fragmentation and long-term cooling of decay heat generating core debris. The qualification of this SAMS needs to address two main severe accident issues: debris bed coolability and steam explosion. 

     

    Since the coolability of a debris bed is determined by the bed’s  properties including debris particle’s size distribution and morphology as well as the bed’s configuration and inhomogeneity, it is important to investigate the mechanisms of melt jet breakup and resulting fragmentation in water which affect debris bed’s properties. Hence, the first part of this thesis is concerned with characterization of melt jet breakup and resulting debris particles.  A series of jet breakup experiments have been conducted in small scale with simulant binary oxide melt mixtures of WO3-Bi2O3, WO3-ZrO2 and Wood's metal. The experiments reveal significant influence of melt superheat, water subcooling, melt jet diameter and material properties on debris size and morphology. Specifically, transition in debris size and morphology is found to occur at a specific water subcooling range. The difference in debris properties at varied melt release conditions is attributed to the competition between liquid melt hydrodynamic fragmentation and thermomechanical fracture of quenched particles.

     

    The second part of this thesis work is dedicated to provide a new understanding of steam explosion (SE) with the support of small-scale experiments at the level of droplets. Self- and externally-triggered SE experiments are conducted with simulant binary oxide melt mixtures in the temperature range of 1100 to 1500°C. The dynamics of steam explosion process is recorded using a sophisticated simultaneous visualization system of videography and X-ray radiography. Further, the influence of melt composition on steam explosion is summoned.  The results reveal that a droplet of eutectic composition is more explosive than a droplet of non-eutectic composition since latter may form a mushy zone which thereby limits the amount of melt actively participating in a steam explosion. To reduce the temperature difference between simulant melt and corium, investigation was extended to perform high temperature (˃2000°C) melt experiments. For this purpose, steam explosion of a molten Al2O3 droplet was investigated, and the experimental results confirmed that Al2O3 melt can undergo spontaneously triggered steam explosion at a high melt superheat and high subcooling. Within the context the effects of melt superheat and water subcooling were obtained.

     

    The third part of this thesis is concerned with the oxidation of metallic melt representing unmixable metallic liquid of molten corium, which interactions with water can be spatially and chronologically separated from the oxidic corium FCI. The objective of the study  is to provide new insights into the characteristics of oxidation of Zr droplet falling in a water pool through a series of small-scale experiments. The dynamics of droplet and bubbles were recorded by high-speed cameras, and the spatial distributions of the elements in the quenched droplet (debris) were acquired by Energy- Dispersive X-Ray Spectroscopy (EDS). The results have shown noticeable influence of generated hydrogen and oxidation heat on droplet behavior and cooling rate. Water subcooling had significant influence on oxidation kinetics, and the oxygen content of the solidified particle increased with decreasing subcooling. Incomplete oxidation of Zr happened before melt crystallization and cooling down in all experiments.  

  • Arlov, Thor Bjørn
    et al.
    Avango, Dag
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Reymert, Per Kyrre
    Gradmålingsstasjonen i Sorgfjorden: en kulturhistorisk dokumentasjon2018Report (Other academic)
    Abstract [sv]

    Rapport från arkeologisk fältforskning vid Sorgfjorden, Svalbard, Juli 2017. Rapporten innehåller en dokumentation av lämningar från den svensk-ryska gradmätningsexpeditionen 1898-1902 i form av kartor, foto och textbeskrivningar. Arkeologisk fältdata finns tillgänlig hos Sysselmannen på Svalbard.

  • Iaffa Nylén, Simon
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Implementing the 2030 Agenda in the municipal spatial planning process: Challenges and opportunities in a Swedish context2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    All the member states of the United Nations adopted the 2030 Agenda unanimously in September of 2015, with the aim of transforming our planet into a sustainable place by 2030. The Agenda includes 17 Sustainable Development Goals (SDGs), spanning over ecological, economic, and social sustainability, which are necessary for the transformation of the planet, and all member states should strive to achieve them. In the Agenda, it is stated several times that local authorities are important for achieving the goals and implementing them in society.

    The Government of Sweden has begun working on the implementation of the Agenda nationally, and believes, like the UN, that it is at the local level, implementation of the Agenda should take place. In this regard, municipalities play a central role, as their areas of activity span over many of the SDGs and are responsible for a sustainable development of land and water areas within its boundaries. The 2030 Agenda could, in this regard, strengthen the municipal spatial planning. This paper aims at investigating how municipalities implement the Agenda in their organization, how urban planners and plan architects address sustainability in their projects, and how the Agenda could support that.

    The results of this thesis show that the implementation of the Agenda in the examined municipalities is weak. Urban planners and plan architects have not received information or training on how to apply the Agenda to their work, and the SDGs are not usually used in projects. Several barriers are in the way of a smooth implementation, from lack of knowledge, conflict of interest, unspecific sustainability goals, to ambiguities in how to define sustainable development within the municipality. One way to overcome these barriers is to address the Agenda in the comprehensive plan of the municipality.

    On the other hand, the results show that there is a clear way of working with sustainability in large spatial planning project. By defining, early in the process, what sustainability means in the context of the project, setting ambitious goals and the general structure before involving developers in the process, the municipality could create a common understanding of what sustainable development means for the project, ensure that developers meet the sustainability requirements, and improve the conditions for a continued sustainable development of the project.

    Implementing the Agenda and SDGs early in this process, will assist the municipality to set relevant goals, and be a first step in concretizing the SDGs to tangible, local goals.

  • Smirnov, Serguei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Anoshkin, Ilya V.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Lioubtchenko, Dmitri
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Oberhammer, Joachim
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Carbon Nanotube Layer Modeling for Computer Simulation of Optically Controlled Phase Shifters2018Conference paper (Refereed)
    Abstract [en]

    We propose an approach for efficient modeling of thin carbon nanotube layers for full-wave device simulations without increasing the number of simulation mesh cells. A surface impedance, used in computer simulations, is calculated from the dielectric constant of the material. The dielectric constant is modeled by a Drude–Lorentz resonance, fitted to experimental results. The approach allowed to study the nanotube-induced losses and finite-size resonance effects in optically-controlled, dielectric rod waveguide-based phase shifters. The correctness of the model was verified both by the simulated and the measured S-parameters in the W-band.

  • Ye, He
    et al.
    Martinez, Matias
    Monperrus, Martin
    A Comprehensive Study of Automatic Program Repair on the QuixBugs BenchmarkManuscript (preprint) (Other academic)
    Abstract [en]

    Automatic program repair papers tend to repeatedly use the same benchmarks. This poses a threat to the external validity of the findings of the program repair research community. In this paper, we perform an automatic repair experiment on a benchmark called QuixBugs that has been recently published. This benchmark has never been studied in the context of program repair. In this study, we report on the characteristics of QuixBugs, and we design and perform an experiment about the effectiveness of test-suite based program repair on QuixBugs. We study two repair systems, Astor and Nopol, which are representatives of generate-and-validate repair technique and synthesis repair technique respectively. We propose three patch correctness assessment techniques to comprehensively study overfitting and incorrect patches. Our key results are: 1) 13/40 buggy programs in the QuixBugs can be repaired with a test-suite adequate patch; 2) a total of 22 different plausible patches for those 13 buggy programs in the QuixBugs are present in the search space of the considered tools; 3) the three patch assessment techniques discard in total 12/22 patches that are overfitting. This sets a baseline for future research of automatic repair on QuixBugs. Our experiment also highlights the major properties and challenges of how to perform automated correctness assessment of program repair patches. All experimental results are publicly available on Github in order to facilitate future research on automatic program repair.

  • Hatem, Ahmed
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Model Predictive Control for pathtracking and obstacle avoidance of autonomous vehicle2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The concept of autonomous vehicles has been widelyexplored lately by, among others, automotive companies as away to for example improve fuel efficiency or to gain accessto environments which pose a danger to human operators.Model Predictive Control (MPC) has traditionally been used tocontrol systems with slower dynamics but with the emergence ofmore powerful computers it is now being used in systems withconsiderably faster dynamics as well. One of the main strengthsof MPC is its ability to handle constraints which are present inall physical systems. The aim of this thesis was to develop a singlelayer linear controller for path tracking and obstacle avoidanceof an autonomous car. Its ability to minimize the deviations tothe reference path while clearing static obstacles was evaluated.Focus was placed on the tracking problem hence no trajectoryplanning system was implemented. Instead a predefined pathwas used. Simulations were developed in MATLAB based on thekinematic bicycle model. The performance of the controller wasfurther tested at Smart Mobility Lab (SML) in KTH where amodified R/C car was controlled through Robotics OperatingSystem (ROS). The results from the experiments showed that itwas able to successfully evade the obstacles while tracking thepath. However, in the experiments the vehicle failed to respectthe requirements on maximum deviation from the obstacles andthe path.

  • Petrov, Svetlomir
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Patch Delivery Infrastructure in SCADA Systems2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As other technologies, the SCADA architecture, whose origin can be traced back to midtwentiethcentury, was not designed initially with security in mind. Recent cyber-attacks andsecurity incidents show that approaches like security through obscurity and air-gapping thesystems are not relevant anymore. An analysis from E-ISAC about the cyber-attack on theUkrainian power grid shows that the risk could be significantly mitigated with prioritizing andpatching the known vulnerabilities on the most critical assets in an organization. The problem ishow to assure the secure deployment of patches in a timely manner and to ensure that they areapplied to the correct targets. This is achievable with a patch delivery infrastructure.Within a heterogeneous environment with several operating system platforms, multiple use casesand stringent security requirements there is no standardized design which solves the problem.This was the case in large SCADA manufacturer who provides patch management service to itscustomers around the globe. The goal of the degree project was to study and model its currentpatch management workflow, the current patch delivery infrastructure and propose new designsand approaches based on the collected use cases, that must be covered by the company, andrequirements from academia and industry standards. Two new concrete designs were proposedwith different level requirements fulfilment and changes which must be done compared to the asisstate in the company. They are based on client-server and configuration manager approaches.A third multi-platform configuration management solution is briefly outlined and will require acomplete change in the patch delivery infrastructure.Lastly, an evaluation framework was applied on the current patch delivery infrastructure and thetwo concrete design proposals which ranks them according to the fulfilment of the collected usecases and requirements. One should note that the best solution which solves the problem mightnot be the best solution to be implemented in the company. Future work will be needed to makeprototypes, test and evaluate them with a better framework developed by the enterprise’s experts.

  • Sundaram, Dinesh
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Materials Technology.
    The Effect of Solidification time and Cooling rate on the Ultimate tensile Strength of Grey Cast Iron.2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Tensile strength modelling is usually done to predict the mechanical properties of lamellargraphite iron considering microstructural features. This work attempts to create a simplifiedmodel incorporating cooling rate and solidification time without considering themicrostructural features. This model will save time and cost in industry with the presence of acommercially available software such as Magmasoft which simulates solidification time andcooling rate. A plate model was designed for this purpose as the test geometry to createvariation in solidification time and cooling rate. By altering fraction solid, thermalconductivity, specific heat capacity in Magmasoft, a good fit was created between simulatedcooling curve and experimental cooling curves. The experimental UTS data of samples fromthree moulds were investigated and a regression model was created using statistics toolMinitab. The effect of solidification time and alloying on the graphite length Lmax was studiedfor twelve samples from each mould. Quantification of the effect of cooling rate and alloyingon the pearlitic properties of grey iron like matrix microhardness, pearlite inter-lamellarspacing was also investigated in this work.The developed model has sixty three percent correlation and explains UTS well in terms ofsolidification time and cooling rate. Microhardness measurements show that there is an almostlinear relationship between the cooling rate and microhardness of the matrix structure.Microhardness data also provides an overview of the pearlite fineness/interlamellar spacing.Analysis of the outliers showed that the presence of free ferrite on a fully pearlitic structurereduces the UTS significantly. Comparison of the regression model obtained from this workwith previous work showed that, there is a reduction in the predicted strength with this model.The effort to identify the reason for this reduction was not successful and needs furtherinvestigation. Pearlite inter-lamellar spacing measurement was not accurate. The relationshipbetween pearlite interlamellar spacing and matrix microhardness needs to be investigated inthe future using a better technique for pearlite spacing measurement. This will be useful tounderstand the effect of cooling rate on pearlite spacing and consequently on the UTS of greycast iron.

  • Public defence: 2019-01-17 13:00 F3, Stockholm
    Ringh, Axel
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Multidimensional inverse problems in imaging and identification using low-complexity models, optimal mass transport, and machine learning2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis, which mainly consists of six appended papers, primarily considers a number of inverse problems in imaging and system identification.

    In particular, the first two papers generalize results for the rational covariance extension problem from one to higher dimensions. The rational covariance extension problem stems from system identification and can be formulated as a trigonometric moment problem, but with a complexity constraint on the sought measure. The papers investigate a solution method based on varia tional regularization and convex optimization. We prove the existence and uniqueness of a solution to the variational problem, both when enforcing exact moment matching and when considering two different versions of approximate moment matching. A number of related questions are also considered, such as well-posedness, and the theory is illustrated with a number of examples.

    The third paper considers the maximum delay margin problem in robust control: To find the largest time delay in a feedback loop for a linear dynamical system so that there still exists a single controller that stabilizes the system for all delays smaller than or equal to this time delay. A sufficient condition for robust stabilization is recast as an analytic interpolation problem, which leads to an algorithm for computing a lower bound on the maximum delay margin. The algorithm is based on bisection, where positive semi-definiteness of a Pick matrix is used as selection criteria.

    Paper four investigate the use of optimal transport as a regularizing functional to incorporate prior information in variational formulations for image reconstruction. This is done by observing that the so-called Sinkhorn iterations, which are used to solve large scale optimal transport problems, can be seen as coordinate ascent in a dual optimization problem. Using this, we extend the idea of Sinkhorn iterations and derive a iterative algorithm for computing the proximal operator. This allows us to solve large-scale convex optimization problems that include an optimal transport term.

    In paper five, optimal transport is used as a loss function in machine learning for inverse problems in imaging. This is motivated by noise in the training data which has a geometrical characteristic. We derive theoretical results that indicate that optimal transport is better at compensating for this type of noise, compared to the standard 2-norm, and the effect is demonstrated in a numerical experiment.

    The sixth paper considers using machine learning techniques for solving large-scale convex optimization problems. We first parametrizes a family of algorithms, from which a new optimization algorithm is derived. Then we apply machine learning techniques to learn optimal parameters for given families of optimization problems, while imposing a fixed number of iterations in the scheme. By constraining the parameters appropriately, this gives learned optimization algorithms with provable convergence.

  • Lenkei, Zsolt
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport Planning, Economics and Engineering.
    Crowdsourced traffic information in traffic management: Evaluation of traffic information from Waze2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The early observation and elimination of non-recurring incidents is a crucial task in traffic management. The performance of the conventional incident detection methods (traffic cameras and other sensory technologies) is limited and there are still challenges in obtaining an accurate picture of the traffic conditions in real time. During the last decade, the technical development of mobile platforms and the growing online connectivity made it possible to obtain traffic information from social media and applications based on spatial crowdsourcing. Utilizing the benefits of crowdsourcing, traffic authorities can receive information about a more comprehensive number of incidents and can monitor areas which are not covered by the conventional incident detection systems. The crowdsourced traffic data can provide supplementary information for incidents already reported through other sources and it can contribute to earlier detection of incidents, which can lead to faster response and clearance time. Furthermore, spatial crowdsourcing can help to detect incident types, which are not collected systematically yet (e.g. potholes, traffic light faults, missing road signs). However, before exploiting crowdsourced traffic data in traffic management, numerous challenges need to be resolved, such as verification of the incident reports, predicting the severity of the crowdsourced incidents and integration with traffic data obtained from other sources.

    During this thesis, the possibilities and challenges of utilizing spatial crowdsourcing technologies to detect non-recurring incidents were examined in form of a case study. Traffic incident alerts obtained from Waze, a navigation application using the concept of crowdsourcing, were analyzed and compared with officially verified incident reports in Stockholm. The thesis provides insight into the spatial and temporal characteristics of the Waze data. Moreover, a method to identify related Waze alerts and to determine matching incident reports from different sources is presented. The results showed that the number of reported incidents in Waze is 4,5 times higher than the number of registered incidents by the Swedish authorities. Furthermore, 27,5 % of the incidents could have been detected faster by using the traffic alerts from Waze. In addition, the severity of Waze alerts is examined depending on the attributes of the alerts.

  • Nyström, Stefan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Shahwan, Sipan
    KTH, School of Architecture and the Built Environment (ABE).
    Optimering av Högskolebibliotek2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The academic library is an important aspect of a students education as it contributes to providing scientific literature. Contemporary society has led to the digitalisation of educational media. Consequently, libraries are becoming more reliant upon the usage of electronic databases as opposed to the usage of printed materials. The interest in the task is rooted in our desire to create an environment where students feel both relaxed and motivated to carry out educational tasks. An implementation of this was done in the form of a rebuilding proposal for the Building Engineering and Design existing facilities of Royal Institute of Technology.

    Our investigation consisted of conducting interviews with staff members from a variety of academic libraries in Stockholm area to gain a useful insight upon the concerns and fundamental issues which many of these members have. Such information allowed us to identify problems in regards to library settings and thereafter overcome it.

    Using current guidelines and standards, a work environment was developed that provides the right conditions for activity-based studies. This applies, for example, to careful planning of artificial light. The relation to natural light was also important, and by Swedish standard requirements for daylight emitting, its influence on the library room could be controlled. Thus we see an example of utilizing and improving the characteristics of the facility from an architectural perspective.

  • Annergren, Björn
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Log Classification using a Shallow-and-Wide Convolutional Neural Network and Log Keys2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A dataset consisting of logs describing results of tests from a single Build and Test process, used in a Continous Integration setting, is utilized to automate categorization of the logs according to failure types. Two different features are evaluated, words and log keys, using unordered document matrices as document representations to determine the viability of log keys. The experiment uses Multinomial Naive Bayes, MNB, classifiers and multi-class Support Vector Machines, SVM, to establish the performance of the different features. The experiment indicates that log keys are equivalent to using words whilst achieving a great reduction in dictionary size. Three different multi-layer perceptrons are evaluated on the log key document matrices achieving slightly higher cross-validation accuracies than the SVM. A shallow-and-wide Convolutional Neural Network, CNN, is then designed using temporal sequences of log keys as document representations. The top performing model of each model architecture is evaluated on a test set except for the MNB classifiers as the MNB had subpar performance during cross-validation. The test set evaluation indicates that the CNN is superior to the other models.

  • Stenbom, Agnes
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Understand That Everything is Different and be Humble to the Task: An Exploratory Study on Establishment Challenges for Swedish Micro-Sized Tech Businesses in NYC2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Swedish micro-businesses are encouraged by the government to internationalise and participate in entrepreneurial ecosystems. Yet research on how they should be supported while doing so is thin. Current research on entrepreneurial ecosystems shows that value co-creation breads sustainability, and increased attention is given to intermediary organisations. While scholars stress aligned expectations as key to value co-creation, intermediaries today are basing their actions on what they think businesses need and expect. This study challenges that logic.

    This study focused on the entrepreneurial ecosystem of New York, specifically looking at Swedish technology startups, intermediaries and investors. Trough semi-structured interviews the study sought to understand how congruent startups’ and intermediaries’ perceptions of challenges during business establishment in NYC are, and also, how they could be aligned.

    The study employed the framework of Gioia et al. (2012) when distilling challenges from the interviews. The results show congruence in some identified challenges, with a key difference in their temporal approaches. The intermediaries primarily focused on instrumental challenges and initial barriers-to-entry, while the startups (and investors) in higher regard focused on open-ended challenges related to relationships and legitimacy. This was considered proof of intermediaries employing an outdated theoretical perspective on their role as an instrumental broker. The study thus concluded by suggesting an alternative perspective, emphasizing dynamic and situation-based support.

  • Beckman, Claes
    et al.
    Wahlberg, Ulrik
    Widell, Svante
    Polarization Diversity Antennas1997In: Antenn 97: Nordiskt antennsymposium, 1997, p. 59-65Conference paper (Refereed)
    Abstract [en]

    In this study we investigate how different types of  base station antenna polarization configurations, horizontal/vertical and slanted ±45 degrees, affect the diversity performance in different environments at 1800 MHz. The performance is determined by measurements where  envelope cross-correlation, mean signal levels and diversity gain are studied in urban and suburban small-cell environments. The results are compared with a two branch space diversity scheme, where the antennas are horizontally separated by 20l. The correlation values are in general low, less than 0.7 for more than 90% of the measurements. The horizontal/vertical system suffers though from differences in mean branch signal levels, compared to the ± 45° and space diversity system which always have comparable mean signal levels. The diversity gain of both dual polarized antenna systems are in general about 1dB less than the gain of spatial diversity. The ± 45° scheme performs also about 1dB better than the horizontal/vertical scheme in the urban area. The results indicates that the  ± 45° dual polarized scheme can be attractive in situations where hand-held portables are dimensioning for the cell planning.

  • Hosseini, Arvin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Cirkulär masshantering: En fallstudie om optimerad resurseffektivitet inom projekt Ostlänken2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of the report is to pay attention to the reuse potential of soil masses in infrastructure projects, specifically the East Link Project and how resource efficiency can be optimized. The practical purpose of the study is to contribute to a more sustainable mass management in the East Link Project. This report has been written in the form of a case study with two types of cases where triangulation has been implemented in the research methodology to combine qualitative with quantitative methods. Criterions for the analytical method of the report are based on an overall efficiency assessment, where analyzed criterions are economy, climate and risk. The result indicates that excavated soil masses that are transported by semi-trailers outside the project area to a fictional landfill are costlier and emit more CO2 equivalents than soil masses that are transported by a dumper truck inside the project area for reuse purposes. The analysis indicates that an increased maximum load in combination with a shorter distance is the most cost-efficient option. The study also highlights the importance of including the entire value chain (client-consultant-contractor) as well as updating the industry's otherwise conservative approach to mass management.

  • Mabrouk, Nizar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Mehnaoui, Soumia
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Amorteringskravet: Dess påverkan på bostadspriser och hushållens skuldsättning2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The first of June 2016, an amortization requirement was introduced as a measure to halt the constantly growing household debt in Sweden. The high household debt has been widely discussed over the past few years which has led to the further discussion regarding whether the growing debt means a risk for the macroeconomic and financial stability. Banks and other actors active in the housing market have been both positive and skeptical of the amortization requirement as a measure to reduce the household dept. The actors argue that the consequences can be both positive and negative. The purpose of this essay is to study if and how the amortization requirement so far has affected the house prices and the debt for mortgage loans, and if it has been the ultimate measure to achieve a more stable economy. To achieve the purpose of the essay two research methods were used: qualitative method, interviews and literature studies, and quantitative method, based on statistics. Results suggest that the amortization requirement has had an impact on the housing market. Housing prices have continued to increase but at a slower pace in comparison with previous years, whilst the debt rate has fallen. The amortization requirement is considered more as an educational measure than a measure that reduces household depts. The conclusion drawn from the results is that the amortization requirement has fulfilled its purpose but whether this measure is the most optimal is hard to say.

  • POL CATALÀ, NÚRIA
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Smart Cities Solutions for Refugee Camps: Communication systems review to improve the conditions of refugees2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A large number of refugees are forced to live in refugee camps which lack in both quality of life and infrastructure. Most of them are located in areas without mobile coverage. By contrast, Smart Cities aim to improve the life of its citizens, mainly helped by ICTs. Therefore, refugee camps can also take advantage of the ICTs to enhance the life of refugees.

    The present thesis aims to explore the needs and priorities of refugees, analyse the impact of smart city solutions implemented in refugee camps on the lives of refugees, and identify and analyse currently unused smart city solutions that could meet the needs of refugees in refugee camps and enhance the Sustainable Development Goals.

    The study is carried out through the literature review and interviews with professionals working in NGOs devoted to the refugee issues. The necessity and benefits of ICTs have been analysed and the most promising solutions in the different domains of the refugee camps have been selected and described, including IoT based solutions supported with low power WAN to collect data, and blockchain applications as new protocol for a database. 

  • Sujessy, Libbis
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Climate Change Impact Assessment of a Biochar System in Rural Kenya2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Biochar systems have been beneficial to Kenyan residents living in the rural areas, particularly in Kwale, following recent research interventions. Biochar system starts from the biomass feedstock sourcing, its production method, and finally its application to soil. The aim of this study is to assess the climate change impacts of the application of biochar in smallholder farms and households in rural Kenya, against the traditional agriculture and cooking practices under realistic conditions and from a life cycle perspective. The scope of this study includes the biomass sourcing identification, biomass availability measurement, cooking practice observation and biochar application during planting season (April to May) at one of the rural areas, the Waa Ward in Kwale County under The Biochar Project.

    Field observation was carried out to identify and measure on-farm biomass availability and cooking performance. The identification and measurement of biomass weight were conducted through survey and manual scale, respectively. While the cooking performance was observed with uncontrolled Kitchen Performance Test (KPT) method. A life cycle assessment was conducted to evaluate the climate change impact of biochar system in Kwale. The biochar production method, also called the improved system in this study, is compared against the traditional system. This study focuses at the cookstove used for the two systems, Gastov and three-stone open fire. Gastov is a type of Top-Lit UpDraft (TLUD) natural draft gasifier cookstove investigated.

    The biomass measurement established the biomass and energy availability on-farms in Kwale. Meanwhile, the KPT found that Gastov required lesser fuel for cooking due to higher thermal efficiency in comparison to three-stone open fire. The LCA results showed that the improved system performs better than the traditional system in terms of climate change impacts and that the improved system potentially offset GHG emissions caused by traditional system as well as generates a net carbon credit. Lastly, the ‘hotspot’ of the improved system was identified in the cooking process, although it was also significantly better than the traditional cooking process. The sensitivity analysis showed that both fraction of stable carbon and fraction of non- renewable biomass (fNRB) were major factors in the biochar system in Kwale, Kenya.

    The conclusion is that the biochar system presents more advantages as applied in Kwale compared to the traditional system through biomass management, improved cooking method, and biochar application to soil.

  • Wickberg, Adam
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Pellucid Paper: Poetry and Bureaucratic Media in Early Modern Spain2018Book (Refereed)
    Abstract [en]

    Adam Wickberg's Pellucid Paper is an interdisciplinary study of the materiality of Early Modern poetry and its relation to political power, memory and subject constitution. The book explores the broad media history in which some of the most canonical Spanish Golden Age poetry was produced. It departs from the intersection of media theory, historiography and materiality of Early Modern culture in a radical rethinking of the nature of the relationship between the imaginary and the real using the concept of cultural techniques. Working with the operative sequences of the material and the symbolic of epistemological configurations of art, literature and power relations, it demonstrates how media and materiality were a crucial part of both the political and the aesthetic already in Early Modernity. It studies these operations in Early Modern Spain in the reign from Philip II to Philip IV. The development of a paper based bureaucracy as a means of sustaining large-scale power relations bridging distances in space and time forms the locus of the book. Pellucid Paper is informed by German Media theory and specifically the more recent developments of Cultural Techniques, which enables a fresh and imaginative take on Early Modern culture. The book offers a radical account of the dynamic relationship between the death oriented aesthetics of vanitas, techniques and media of storage and a form of mediated presence that permeates the inseparable spheres of the political and the aesthetic.

  • Lindén, David
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Exploration of implicit weights in composite indicators: The case of resilience assessment of countries’ electricity supply2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Composite indicators, also called indices, are widely used synthetic measures for ranking and benchmarking alternatives across complex concepts. The aim of constructing a composite indicator is, among other things, to simplify and condense the information of a plurality of underlying indicators. However, to avoid misleading results, it is important to ensure that the construction is performed in a transparent and representative manner. To this end, this thesis aims to aid the construction of the Electricity Supply Resilience Index (ESRI) – which is a novel energy index, developed within the Future Resilient Systems (FRS) programme at the Singapore-ETH Centre (SEC) – by looking at the complementary and fundamental component of index aggregation, namely the weighting of the indicators. Normally, weights are assigned to reflect the relative importance of each indicator, based on stakeholders’ or decision-makers’ preferences. Consequently, the weights are often perceived to be importance coefficients, independent from the dataset under analysis. However, it has recently been shown that the structure of the dataset and correlations between the indicators often have a decisive effect on each indicator’s importance in the index. In fact, their importance rarely coincides with the assigned weights. This phenomenon is sometimes referred to as implicit weights. The aim of this thesis is to assess the implicit weights in the aggregation of ESRI. 

    For this purpose, a six-step analytical framework, based on a novel variance-based sensitivity analysis approach, is presented and applied to ESRI. The resulting analysis shows that statistical dependencies between ESRI’s underlying indicators have direct implications on the outcome values – the equal weights assigned a-priori do not correspond to an equal influence from each indicator. Furthermore, when attempting to optimise the weights to balance the contribution of each indicator, it is found that this would require a highly unbalanced set of weights and come at the expense of representing the indicators in an effective manner. Thereby, it can be concluded that there are significant dependencies between the indicators and that their correlations need to be accounted for to achieve a balanced and representative index construction. Guided by these findings, this thesis provides three recommendations for improving the statistical representation and conceptual coherence of ESRI. These include: (1) avoid aggregating a negatively correlated indicator – keep it aside, (2) remove a conceptually problematic indicator – revise its construction or conceptual contribution, and (3) aggregate three collinear and conceptually intersecting indicators into a sub-index, prior to aggregation – limit their overrepresentation. By revising the index according to these three recommendations, it is found that ESRI showcases a greater conceptual and statistical coherence. It can thus be concluded that the analytical framework, proposed in this thesis, can aid the development of representative indices. 

  • Ciftci, Baris
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Gross, James
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Norrga, Staffan
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Kildehöj, Lars
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Nee, Hans-Peter
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    A Proposal for Wireless Control of Submodules in Modular Multilevel Converters2018Conference paper (Refereed)
    Abstract [en]

    The modular multilevel converter is one of the most preferred converters for high-power conversion applications. Wireless control of the submodules can contribute to its evolution by lowering the material and labor costs of cabling and by increasing the availability of the converter. However, wireless control leads to many challenges for the control and modulation of the converter as well as for proper low-latency high-reliability communication. This paper investigates the tolerable asynchronism between phase-shifted carriers used in modulation from a wireless control point of view and proposes a control method along with communication protocol for wireless control. The functionality of the proposed method is validated by computer simulations in steady state.

  • Zulkafli, Zed
    et al.
    Perez, Katya
    Vitolo, Claudia
    Buytaert, Wouter
    Karpouzoglou, Timothy
    Public Administration and Policy Group, Wageningen University, Netherlands.
    Dewulf, Art
    De Bièvre, Bert
    Clark, Julian
    Hannah, David M.
    Shaheed, Simrita
    User-driven design of decision support systems for polycentric environmental resources management2017In: Environmental Modelling & Software, ISSN 1364-8152, E-ISSN 1873-6726, Vol. 88, p. 58-73Article in journal (Refereed)
    Abstract [en]

    Open and decentralized technologies such as the Internet provide increasing opportunities to create knowledge and deliver computer-based decision support for multiple types of users across scales. However, environmental decision support systems/tools (henceforth EDSS) are often strongly science-driven and assuming single types of decision makers, and hence poorly suited for more decentralized and polycentric decision making contexts. In such contexts, EDSS need to be tailored to meet diverse user requirements to ensure that it provides useful (relevant), usable (intuitive), and exchangeable (institutionally unobstructed) information for decision support for different types of actors. To address these issues, we present a participatory framework for designing EDSS that emphasizes a more complete understanding of the decision making structures and iterative design of the user interface. We illustrate the application of the framework through a case study within the context of water-stressed upstream/downstream communities in Lima, Peru.

  • SPRINGER, JULIAN
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    KINNUNEN, MIKO
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Value creation through digital services in start-up support organisations2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background and purpose - Digitisation is connecting various business actors to create interconnected ecosystems through digital platforms. Meanwhile entrepreneurial ecosystems are offering various benefits for start-ups e.g. through support organisations that offer services for them. Currently, these start-up support organisations face the challenge of leveraging digital services to create value for their member start-ups. The purpose of this study is to investigate how the digital services offered in start-up support organisations create value for start-ups. Approach - From a theoretical perspective, the sociology of value and service dominant logic concepts such as value co-creation and service ecosystems are considered. Qualitative methods were used to conduct a pre-study and an in-depth case study with a start-up hub in Stockholm's entrepreneurial ecosystem. Data was collected using 18 semi-structured interviews with start-ups and other actors in the ecosystem and participant observations of 17 events. Findings - Needs and challenges for start-ups were identified and mapped against the digital services used by the start-ups. These services facilitate interaction between various actors in the start-up hub. Seven interconnected value types for the start-ups were identified emerging from the use of digital and non-digital services in the start-up hub. Moreover, many of the digital services are not provided by the start-up hub alone but in collaboration with other actors, connecting the start-up hub to other actors in the start-up ecosystem. Research limitations and implications - The findings contribute to the understanding of how start-up support organisations leverage digital services to support their member start-ups. The connection of digital service usage to the creation of various value types provides a theoretical concept to research about service ecosystem. As the study has been conducted with a limited number of respondents and events in Stockholm, further research in other ecosystems and using different methods is suggested to ensure generalisability of the findings of this study. Practical implications - A number of practical suggestions for start-up support organisations can be derived from the findings, including that start-up support organisations can benefit from establishing and moderating a digital community, involving several actors from the ecosystem and continuously adapting digital services to the changing environment and needs of start-ups. Originality - To the best knowledge of the authors, this is the first study to investigate digital services in entrepreneurial ecosystems from the perspective of value in service ecosystems.

  • Public defence: 2019-01-18 13:00 Kollegiesalen, Stockholm
    Wadi, Amer
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Soil-Steel Composite Bridges: Research advances and application2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Soil-steel composite bridges are considered competitive structures being an economical alternative to similar span concrete bridges. This frequently stimulates practitioners to push their design limits and expand the different areas of application including their performance in sloping terrain. This also implies that most design methods are continuously being developed to address new market challenges and at the same time to seek for better design and construction.

    This thesis compiles the recent research efforts to advance the knowledge on the structural performance of soil-steel composite bridges (SSCB). The first part of the thesis investigates the performance of SSCB in sloping terrain, where numerical simulations are used to predict the behaviour of three case studies. This includes structural response under sloped soils and also avalanche loads (Paper I and Paper II). The research enabled to realize the importance of soil configuration around the wall conduit and its influence on the structural response. While the presence of surface slopes emphasizes the susceptibility of SSCB with low depths of soil cover, higher covers may help in reducing the influence of steep slopes and avalanche loads. It was also found that the downhill soil configuration has substantial effects on the flexural response. The findings of the study were also used to provide methods for preliminary estimates of normal forces under sloped soils and avalanches.

    To better understand the load bearing capacity of SSCB, the second part of this thesis deals with the behaviour of large-span structures. It includes the use of finite element method simulations (FEM) for the analysis and the prediction of a previous full-scale loading-to-failure test (Paper III). The study also presents response predictions on the ultimate capacity of a large-span structure pertaining to its ongoing preparation for a full-scale field test (Paper IV). The thesis also includes discussions and possible refinements on current design equations concerning buckling calculations and live load effects. The results of the study have allowed to realize the major role of the soil load effects on the subsequent formation of yield areas and failure loads. It is found that the load position has a direct influence on the ultimate capacity especially for large-span structures. The study also highlighted the variations in the distribution of the live load sectional forces in both the circumferential and the transverse directions of the corrugations. Furthermore, possible refinements are proposed on current design equations of which are believed closely relevant on the path for the design development of large-span structures.

  • Segersten, Kristoffer
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    ZHAI, KEREN
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Obstacles for Remote Air Traffic Services: A Multilevel Perspective2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Air traffic services (ATS) play an important role for flight safety. Remote air traffic services (RATS) represent a novel, more digitalized, ATS solution. In some aspects, RATS can be argued to outperform conventional ATS. However, as it entails various sociotechnical obstacles, making RATS the dominant solution for ATS is challenging. An inadequate awareness of such sociotechnical obstacles potentially impedes the competitiveness of RATS in general and the RATS providers in particular. This study intends to - from a sociotechnical perspective - identify main obstacles as faced by RATS when aspiring to become the dominant solution for ATS. In order to identify such obstacles, an abductive case study has been conducted. Empirical data was primarily gathered by semi-structured interviews with 10 key stakeholders involved, directly or indirectly, with RATS. The study is delimited to principally gather empirics from Sweden and the United Kingdom. Theoretical concepts of Large Technical Systems (LTS) and the Multilevel Perspective (MLP) are employed to understand and analyze the empirical data. The identified obstacles faced by RATS are mapped into the different levels of the MLP. Obstacles have been identified in all levels of the MLP. The most prominent obstacles seem to lay in social aspects of change processes, a proposition-perception gap, and connectivity infrastructure dependency.

  • Sarainmaa, Olli
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    Large Efficient Maritime Propeller without Hull Pressure Excitations2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis studies competence of simplified simulation methods for boosting simulation.  The most efficient propulsion unit has higher amount of power compared to less efficient propulsion units in boosting. Boosting is relevant subject to study due to new concept. New concept allows a larger diameter for the propeller which increases the efficiency of the propeller. New concept relies on the idea to have the propeller behind the hull.

     

    The thesis is restricted to study displacement hulls from a point of view of propulsion efficiency. Large cruise ship model is utilized in this thesis to identify boosting related effects efficiently. Model tests reports of this concept are used as a baseline and a comparison material for two methods that are tested in this thesis. These methods are Matlab simulation code and OpenFOAM as the CFD software.

     

    New propulsion arrangement concept is more efficient than current solutions for this hull type according to model tests. Trend of the CFD and Matlab simulation results matches well with model test results for boosting. Matlab simulation is evidently more time efficient solution than CFD simulation for boosting. Simplified CFD simulation is sufficiently accurate to study boosting concept with this research setup. Matlab and CFD simulations can be combined to obtain the most efficient solution to analyze the most effective load division for boosting.

     

    Different types of hulls should be simulated and results should be verificated with model or full scale tests. In addition, ships with old two shaft arrangements could be converted to have two smaller pods and center line propeller in order to have better comparison with current methods. Scaling factors increases the uncertainty for new concepts; therefore full scale measurements are required.

  • Sánchez, Ginés
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Internationalization strategy choice for micromultinationals: a development framework2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Micro-multinational is a relatively new term and there are still very few studies about how micromultinationals choose their foreign entry market modes when internationalizing. This thesis attempts to add new knowledge filling the gap between the internal resources of a company and the foreign entry market mode selected for its internationalization process. Furthermore, a systematic methodology that combines internal resources with the selection of the foreign entry market mode will be developed with the goal of aligning the competitive advantages of the company along its international structure. The methodology that this research employs will show how to combine the internal resources of the case study company and its needs when internationalizing based on the characteristics of each foreign entry market mode. The first step of the methodology is determining the variables that categorize each foreign entry market mode that companies implement. Then, the application of the Resource-based View will show the possible competitive advantages of the case study company. Lastly, accounting for the requirements that the case study company has when internationalizing, the possible competitive advantages, derived from the Resource-based View, will be combined with the characteristics of each foreign entry market mode to determine effective recommendations for the case study company to implement in its internationalization strategy. The results of this research show that when a company wants to enter into a foreign market, it should evaluate that decision based on its internal resources. Only then will the company be able to exploit its competitive advantages and be successful in the new market. The decision to internationalize is influenced by requirements such as the level of control, commitment, risk and flexibility that the parent company is willing to have in the new foreign market. Hence, these requirements must be taken into consideration carefully during the entire decision process.

  • Samuelsson, Sofia
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Evaluating Servitization in the Manufacturing Equipment Industry2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the manufacturing equipment industry, sensors integrated in manufacturing equipment is a prerequisite for higher levels of servitization, such as maintenance and product support services, as the sensors can provide data of equipment usage. In this study, a framework called Evaluation of readiness of servitization has been developed, where manufacturing equipment companies can evaluate whether they benefit from developing new solutions with a higher level of servitization. In the evaluation of servitization, a company in the manufacturing equipment industry should consider the following three factors; Value proposition’s fulfilment of customer needs, Market acceptance of value proposition and Internal capabilities to develop and deliver the solution. This study shows that all three factors must be considered for a justified evaluation. The study is based on a single case study on the manufacturing equipment company Atlas Copco Industrial Technique, and a literature review on servitization in the manufacturing industry. This study shows that uncertainty about customer needs and market acceptance of the new value proposition that servitization entails, constitute obstacles to develop new solutions with a higher level of servitization. Thereby, it is of great importance to a manufacturing equipment company to assess readiness both internally and externally when evaluating if they benefit from developing new solutions with a higher level of servitization.

  • Balaam, Madeline
    et al.
    Newcastle Univ, Culture Lab, Newcastle NE1 7RU, England..
    Egglestone, Stefan Rennick
    Univ Nottingham, Mixed Real Lab, Nottingham NG5 1PB, England..
    Fitzpatrick, Geraldine
    Vienna Univ Technol, A-1040 Vienna, Austria..
    Rodden, Tom
    Univ Nottingham, Mixed Real Lab, Nottingham NG5 1PB, England..
    Hughes, Ann-Marie
    Univ Southampton, Sch Hlth Sci, Southampton SO17 1BJ, Hants, England..
    Wilkinson, Anna
    Sheffield Hallam Univ, Ctr Hlth & Social Care Res, Sheffield S10 2BP, S Yorkshire, England..
    Nind, Thomas
    Univ Dundee, Sch Comp, Dundee DD1 4HN, Scotland..
    Axelrod, Lesley
    Univ Sussex, HCT Grp, Brighton BN1 9QH, E Sussex, England..
    Harris, Eric
    Univ Sussex, HCT Grp, Brighton BN1 9QH, E Sussex, England..
    Ricketts, Ian
    Univ Dundee, Sch Comp, Dundee DD1 4HN, Scotland..
    Mawson, Susan
    Sheffield Hallam Univ, Ctr Hlth & Social Care Res, Sheffield S10 2BP, S Yorkshire, England..
    Burridge, Jane
    Univ Southampton, Sch Hlth Sci, Southampton SO17 1BJ, Hants, England..
    Motivating Mobility: Designing for Lived Motivation in Stroke Rehabilitation2011In: 29TH ANNUAL CHI CONFERENCE ON HUMAN FACTORS IN COMPUTING SYSTEMS, ASSOC COMPUTING MACHINERY , 2011, p. 3073-3082Conference paper (Refereed)
    Abstract [en]

    How to motivate and support behaviour change through design is becoming of increasing interest to the CHI community. In this paper, we present our experiences of building systems that motivate people to engage in upper limb rehabilitation exercise after stroke. We report on participatory design work with four stroke survivors to develop a holistic understanding of their motivation and rehabilitation needs, and to construct and deploy engaging interactive systems that satisfy these. We reflect on the limits of motivational theories in trying to design for the lived experience of motivation and highlight lessons learnt around: helping people articulate what motivates them; balancing work, duty, fun; supporting motivation over time; and understanding the wider social context. From these we identify design guidelines that can inform a toolkit approach to support both scalability and personalisability.

  • PORAT, INGRID
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    HOVSTADIUS, KLARA
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    A Business Model Perspective on Additive Manufacturing2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Additive manufacturing (AM) is an immature manufacturing technology which is often considered to have the potential of disrupting the manufacturing industry and many industrial companies are currently investigating how they can position themselves within the AM market. Technological innovations alone are often insufficient to fully exploit the benefits of new technology and requires to be accompanied with business model innovation. Consequently, companies face challenges to find guidance related to the application of AM; what to offer and to whom (value proposition), how to deliver such offering (value creation) and how to capture the profit (value capture) – that is, how to structure an AM business model. Therefore, this research investigates how large incumbent manufacturing companies tackle the emerging AM market from a business model perspective. The research unpacks the common themes within three business model components (value proposition, value creation and value capture) in the context of an AM business model, where theme 5 is contradicted by theory and by several other themes: 1. Immature demand 2. Internal cases as a starting point 3. Knowledge offerings 4. End-to-end solutions 5. Broad customer focus 6. Start in a technology niche, then expand 7. Invest in machines to learn AM 8. Change in designer mindset required 9. Partnerships to drive the AM market forward 10. A shift in power 11. Close customer relations 12. It is a race to the market The research is based on a multiple-case study consisting of 16 interviews at six different companies and two universities.

  • Public defence: 2018-12-20 10:00 Pacific, Stockholm, Sweden
    Liljenström, Carolina
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Life cycle assessment in early planning of transport systems: Decision support at project and network levels2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Swedish Climate Policy Framework implies that the Swedish transport sector must reduce its greenhouse gas emissions to nearly zero by 2045. Previous studies have – using life cycle assessment – shown that indirect greenhouse gas emissions from the vehicle and infrastructure life cycle are significant and should be considered in transport policy and planning of transport systems, in addition to direct emissions of vehicle operation.

    The aim of this thesis is to contribute with knowledge on climate impact and primary energy use of transport systems for decision-support in early planning at project and network levels, and evaluate and demonstrate how life cycle climate impact and primary energy use can be assessed in early planning. This thesis includes three papers that contribute to achieving this aim. Paper I developed a methodological approach to assess annual climate impact and primary energy use of Swedish road, rail, air, and sea transport infrastructure at a network level. Paper II then expanded this system to the assessment of the Swedish transport system at a network level, including national and international freight and passenger transport by road, rail, air, and sea. At the project level, Paper III examined how LCA can be used as decision-support in choice of road corridor, considering the practical prerequisite of data availability in early planning and usefulness of results in the decision-making process.

    Paper I showed that the annual climate impact of Swedish transport infrastructure is around 3 million tonnes CO2 equivalents and that the annual primary energy use is around 27 TWh. Road infrastructure accounted for the largest proportion of impacts – around 70% of the climate impact and around 80% of the energy use. Paper II showed that the annual climate impact of the Swedish transport system was around 44 million tonnes CO2 equivalents and the primary energy use was around 178 TWh. Road transport and aviation together accounted for 90% of the climate impact and primary energy use. Indirect impacts were significant, especially for road and rail transport, accounting for 30% of the total climate impact and primary energy use. Paper III found that (1) collection of project specific data should focus on parameters that differentiate the road corridors, that can be influenced in early planning, and that are not directly related to the road length and (2) life cycle assessment based models used in early planning should include nation specific generic data approved by the national road authority. 

  • Artman, Henrik
    et al.
    Edlund, Lena
    Herzing, Mathias
    Stockholm Universitet.
    Jacobsson, Adam
    Stockholm Universitet.
    Chapter 1 Introduction2016In: Efficient Environmental Inspections and Enforcemen / [ed] Herzing, M., Jacobsson, A., Naturvårdsverket , 2016, p. 246-Chapter in book (Other academic)
  • Artman, Henrik
    et al.
    Brynielsson, Joel
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Herzing, Mathias
    Stockholm University.
    Jacobson, Adam
    Stockholm University.
    More efficient environmental inspections and enforcement2016In: Efficient Environmental Inspections and Enforcement / [ed] Herzing, M., Jacobsson, Adam, Naturvårdsverket , 2016, p. 246-Chapter in book (Other academic)
  • Artman, Henrik
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID.
    A scenario for future informationmanagement in environmentalinspections and enforcement2016In: Efficient Environmental Inspections and Enforcement, Naturvårdsverket, 2016, , p. 25p. 198-213Chapter in book (Other academic)
  • Kritikou, Sofia Kristina
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Service and Energy Systems.
    Evaluation of acoustic, visual and thermal comfort perception of students in the Educational Building at KTH Campus: A study case in a university building in Stockholm2018Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    In recent years the focus and application of sustainability in buildings has risen. Both for environmental and human well-being reasons. The quality of the indoor environment affects the well-being, productivity and work performance, but it can also affect the occupants negatively, like increasing risks of different diseases and health issues. A good indoor environment alongside with sustainable materials, proper HVAC (Heating, ventilation, and air conditioning) installations and building code regulations contribute to a sustainable solution with low environmental impact and reduced energy consumption. Since buildings alone are responsible for 38% of all human GHG (Greenhouse gas) emissions (Wikipedia, 2017), most countries recommend new more sustainable solutions to reduce that percentage. For example, in the EU, the 2020 climate and energy package targets to: cut 20% in greenhouse gas emissions, 20% of EU energy from renewables and 20% improvement in energy efficiency (European Comission, n.d.).

    In addition to the positive aspect of low environmental impact new constructions have, they also create a good living or working environment for the users. Studies have shown that a better indoor quality increases the productivity and work performance, but most of all the occupants feel comfortable and satisfied with their environment. A great number of papers have reviewed the acoustic, visual, thermal comfort and indoor air quality, which are main aspects of the indoor climate. Most papers focus on the users’ perception of these four aspects as well as other parameters that influence the indoor environment (architectural geometry, materials, etc.). Similarly, in this study case I focus on two different methods of obtaining the results, the objective method that contains the indoor environment measurements and the subjective method which includes a questionnaire created specifically for this research project.

    By obtaining these two sets of data, key focus points are developed, such as if the building’s certification meets the recommendations of Miljöbyggnad, what aspects influence the students’ perception the most, and whether there are any distinct connections between measured and calculated data. This study case was developed in a university building in Stockholm, where the four main aspects of the indoor environment were evaluated. The physical parameters such as temperature, air velocity, relative humidity, CO2 concentration and acoustics were measured in five different classrooms. In addition, a survey was developed for this study which included perception questions of the thermal, visual, acoustic comfort and indoor air quality. As found in other studies, gender and climate zone origin affected the overall indoor environmental perception. Even though the majority of both genders voted for “no change”, the remaining females answered that they preferred the conditions warmer. Also, the majority of answers from all climate zones were “no change”. However, the second highest opinion for students from warmer climate zones was “warmer”, which has also been found in other studies. Significant negative correlations were found between the acoustics and the satisfaction level of the acoustic comfort. Similarly, high correlations were observed between the visual comfort satisfaction level and the three aspects influencing it. Furthermore, the results showed that all physical measurements influenced the students’ thermal comfort and indoor air quality perception. All measurements obtained indicated a good indoor environment in all classrooms, and all values were between the Swedish Standards recommendations. Low correlation was found between the measured PVM and the AMV from the questionnaires even though all the values were among the limitations.

    Lastly, this study reviews methods that could be applied to similar future studies and, discusses what kind of errors to avoid in the future. There is still a lot of research that can be developed in order to gain a deeper understanding of the indoor environment and how humans perceive it.

  • Xue, Wei Kai
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Multimodal Line-Field Confocal Optical Coherence Tomography (LC-OCT) for skin cancer diagnostics2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Wakter, Simon
    KTH, School of Engineering Sciences (SCI), Physics.
    Technological Feasibility of Water Desalination using SMRs2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Rydell, Simon
    KTH, School of Engineering Sciences (SCI), Physics.
    Worm simulation of Hausdorff dimension of critical loop fluctuations2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Renberg, Rasmus
    KTH, School of Engineering Sciences (SCI), Physics.
    Superconductor-Insulator Quantum Phase Transitions in a Dissipative Environment2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Laurenti, Rafael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Martin, Michael
    IVL.
    Stenmarck, Åsa
    IVL.
    Developing Adequate Communication of Waste Footprints of Products for a Circular Economy: A Stakeholder Consultation2018In: Resources, ISSN 2079-9276, Vol. 7, no 4Article in journal (Refereed)
    Abstract [en]

    Relatively few consumers are conscious of the waste generated in the course of producing the goods that they consume, although most are aware of the amount of waste they dispose of. This article reports on a small-scale survey (N = 28) among stakeholders aimed at developing adequate communication of preconsumer waste footprints of consumer goods in the context of the circular economy. Life cycle assessment (LCA) practitioners and consumers assessed five methodological details of an approach for calculating and communicating a product waste footprint (PWF). Most of the respondents expressed that the guidelines described in the proposed PWF methodology are good enough for the purposes of differentiating waste and byproducts, and defining which material flow shall be accounted for. Some LCA practitioners declared that the proposed streamlined method may not be adequate for conveying the environmental significance of waste types. The respondents also expressed that the PWF concept would be primarily useful and/or needed for consumers and government, and in the contexts of improving environmental awareness of consumers, environmental policy making, visualizing waste flows in a circular economy, and improving resource efficiency in industry, and less useful/needed in a business-to-business context. The PWF has been successfully used by diverse stakeholder groups in Sweden mostly to promote sustainable production and consumption across society. A notable example is the ‘invisible waste’ (#invisiblewaste) campaign of the Swedish Waste Management Association (Avfall Sverige). The concerns of the LCA experts have therefore not held true. The symbolic power and parsimony of the PWF concept appears to be effective in sensitizing consumers towards waste issues so that circular economy strategies beyond recycling are possible to be fully realized.