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  • Klasson, Caroline
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Fastighetsmäklarbyråer på sociala medier: Varumärkeskommunikation och digitala strategier för mäklarbranschens nischade aktörer2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stockholm's brokerage world is characterized by fierce competition. This has forced brokerages to focus on the creation of a strong and unique brand. At the same time, the industry is becoming more diversified by the fact that many smaller niche agencies are entering the market. This study investigates how some of these agencies work in order to reach the public with their brands. Emphasis is placed on their digital strategies as well as their work on social media and is compared to some extent with the work of other brokers. There are four main themes of the thesis: the first theme attends to the creation of brands and its importance to brokerage agencies. Thereafter the discrepancy between identity and image, and the work to reduce it is discussed. These two themes are thereafter connected to expectations upon, and benefits from, digital strategies for brand communication. Lastly is  companies and brokerage agencies communication strategies on social media analyzed. The main conclusion of this thesis is that digital strategies require resources, knowledge and energy during the initial phase, and should, in addition to this, be continuously updated. The work which is put in to design the digital strategies will pay off for the brand as well as for the home-owners, whose homes are published on the accounts of the different brokerage agencies.

  • Guban, Mark
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    La Torre Rapp, Viktor
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Carbon mitigation using biomass gasification to displace natural gas, during sponge iron powder production2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Carbon dioxide is one of the green house gases that cause climate changes. Both the European Union and the Swedish government have the goal to reduce the emission of green house gases. The first aim of this project was to calculate the amount of the total emissions when producing Sponge Iron powder at Höganäs for both upstream and process. The calculations showed an emission of 234, 2 k ton per year. The second aim was to calculate the carbon dioxide emissions when using biomass compared to natural gas in the belt furnace. The results showed that there could be made a 4% decrease in emission rates when using biomass. The third aim was to calculate the economical difference between biomass and natural gas as a fuel. After 10 years the using a biomass mix (30% is fiber sludge and the rest 70 % is wood residues) the payback time was reached, considering reduced need of emission allowances (124. 5 €/ton CO2 equivalents), an upfront investment of 13 MSEK, and a 5% depreciation each year .Using the same calculation, but with a higher cost for emission allowances, the payback time was reduced to 2-3 years depending on raw biomass. The fourth aim was to look at emission of other polluting substances and compare the difference between using natural gas versus biomass. Although carbon dioxide levels could be cut by 4% per year other substances emission levels will be higher because of the gasification process, especially NOx and mercury. Further investigation has to be done in order to understand how to manage a increased amount of other substances.

  • Åkerlind, Kristina
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Jefimova, Zenja
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Possible reasons for flaking appearance during cold rolling on an austenitic stainless steel2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The research describes possible reasons why the flaking tendency during cold rolling can vary between different austenitic stainless steels. The flaking phenomenon was observed after a rolling process in Granlund Tools AB’s roll reducing mill “KOR-8”. A literature review was conducted with the purpose of finding a connection between rolling process, austenitic stainless steels and flaking. The laboratory work aimed at revealing possible differences between the flaked material and materials that is known to be cold rolled with high surface finish in the particular machine. In order to come to a conclusion regarding the flaking appearance, scanning electron microscopy (SEM), Vickers hardness test and light optical microscopy (LOM) were performed. The literature review along with the laboratory results made it possible to determine the two major factors affecting the flaking behavior. Two independent analyses revealed what came to be the most important discovery in this study. LOM showed the appearance of a thick oxide scale on the surface of the flaked steel which was further confirmed by SEM-Energy-Dispersive X-ray Spectroscopy that indicated the existence of oxides on the steel’s surface. These observations along with the knowledge that oxide scales grow only during high-temperature processing led to the conclusion that the steel is not appropriate for the cold rolling process due to the earlier steel manufacturing.

  • Gram, Tove
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Vickerfält, Amanda
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Characterization of non-metallic inclusions according to morphology and composition: A comparison of two different steels before and after turning2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Investigation of non metallic inclusions in two different steels from Sandvik was made before and after turning. After dissolving the non-metallic inclusions by electrolytic extraction the particles were analysed manually or by INCA feature. This was referred to as 3D analysis. INCA feature analysis without extraction of particles was also performed, this was referred to as 2D analysis. The aim of the report was to a make a characterization of non-metallic inclusions with respect to chemical composition, aspect ratio, size and shape. The aim was also to compare different investigation methods. Samples were prepared and investigated. It was obtained that inclusions with sulphur content was elongated and crushed during the turning process. Broken sulphides were detected in one of the steels, and broken oxysulphides in the other steel in the electrolytically extracted chips created by turning. The first steel, steel 1, mainly contained sulphide and oxysulphide inclusions, and steel 2 mainly contained oxysulphides. The aspect ratio obtained by 2D analysis of the sulphide inclusions in steel 1 before turning showed similar results to the electrolytic extracted inclusions measured by hand. The aspect ratio increased with the length of the inclusion. However the deviation of data obtained by the 2D analysis was larger than deviation from the extracted particles measured by hand. The reason for this was assumed to be that the 2D method was not able to analyse the true shape of the inclusions e.g. if inclusions were partly concealed by metal matrix. In analysis of steel 2 the average aspect ratio decreased for oxides and increased for oxysulphides after turning. The chemical composition of inclusions did not change after the turning process for neither of the steels. Copper was detected in the electrolytic extracted inclusions, however not in the 2D investigation by SEM. This is an interesting topic for future research.

  • Public defence: 2017-10-26 13:00 Ka-Sal C, Electrum, KTH Royal Institute of Technology, Kista
    Celik, Haris
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    On the Performance of Dynamic TDD in Ultra-Dense Wireless Access Networks2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The appetite for wireless high-data rate services is expected to continue for many years to come and drive the need for more capacity. Ultra-dense networks (UDNs) represent a paradigm shift where each base station (BS) serves only a few user equipments (UEs). By most accounts, most of the traffic will be generated indoor and operate in time-division duplex (TDD). This thesis considers dynamic TDD which has shown to perform well indoor for fluctuating traffic where the shorter communication range enables similar transmit powers to be used in uplink and downlink, but also generates potentially more harmful same-entity interference. Because of the sheer number of cells in UDN, the interference management needs to be both effective and scalable.

     

    In the first part of the thesis, we compare static TDD with non-cooperative dynamic TDD and show that flexible time resource allocation is preferred for indoor UDNs. However, since it only provides a lower bound on performance, additional interference coordination is required. Unfortunately, existing schemes often consider either too few, too many, or simply the wrong interferers. We introduce a scheduling model that relates BS-to-BS interferences measured offline to individual BS activation probability taking into account traffic and propagation environment. Results show that the proposed scheme performs well when interference is high, and optimally when interference is low.

     

    In the second part, we introduce cooperation to utilize the otherwise idle BSs and mitigate same- and other entity interference. Zero forcing (ZF) is employed in the downlink where not only downlink UEs but also uplink BSs are included in the precoding. Since downlink BSs do not know the information to be sent by uplink UEs beforehand, dummy symbols with zero power are transmitted. It shown that both uplink and downlink performance improves at low and medium load. Furthermore, it is possible to trade performance in the two directions at high load.

  • Haasler, Isabel
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Numerical Analysis, NA.
    A predictor corrector method for a Finite ElementMethod for the variable density Navier-Stokes equations2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Constructing Finite Element Methods for the incompressible Navier-Stokes equations that are computationally feasible requires the use of pressure segregation methods such as the predictor corrector scheme. From an algebraic point of view these methods correspond to a preconditioned Richardson iteration on the pressure Schur complement. In this work the theory is extended to a variable density model. We suggest a modified preconditioner and investigate its performance experimentally.

  • Public defence: 2017-10-12 10:00 Kollegiesalen, Stockholm
    Li, Bing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Impact Evaluation of Intentional Electromagnetic Interference (IEMI) on Targeted Loads in Complex Networks Using Analytical Investigations2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With the proliferation of various electronic and electrical devices, IEMI has become a critical issue that may severely threaten the modern society. For practical protection considerations, it is crucial to comprehensively evaluate the potential damages resulted by IEMI. The major objective of this thesis is to study the impacts of IEMI on the targeted load in complex networks. More exactly, with respect to certain IEMI, the characteristics of the resulting frequency response on the targeted load are studied, and the effects of network configurations, i.e., the attribute of load impedances, lengths of lines, parameters of disturbance source, location of source and network structures, are also investigated.

    First, we developed a novel efficient method to solve the frequency response, which is applicable for arbitrary networks. The key idea is decomposing the whole complex network into multiple equivalent units, and performing a recursive approach to efficiently compute the frequency response without losing the precision.

    Subsequently, we studied the periodicity of the load response in the frequency domain. Starting with a simple network, we derived and verified the period of the frequency response. During the study, the periodicity with respect to load and media was discussed.

    Furthermore, with respect to five important time-domain norms, i.e., time-domain peak, total signal energy, peak signal power, peak time rate of change, and peak time integral of the pulse, we considered a parameterized ultra-wideband (UWB) transient as the disturbance source, and thoroughly studied its impacts on the targeted load regarding network configurations, which include load impedance, the lengths of lines and parameters of the UWB transient.

    Finally, we adopted a statistical approach to investigate the receptivity at the targeted load in a network. Via complementary cumulative distribution function, the stochastic IEMI and its effects on the targeted load were studied. Moreover, by statistical approach, we also investigated how the network structure affects the frequency response of the targeted load. The results give suggestions on how to protect the targeted load by varying network structures.

  • Blomquist, Emil
    KTH, School of Engineering Sciences (SCI), Physics.
    A Monte Carlo Approach to Feynman Diagrammatic Series and its Boldication2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Public defence: 2017-11-17 13:00 F3, Stockholm
    Vass, Susanna
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Project Communication.
    The Business Value of BIM: Elaborating on Content and Perspective2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The expectations on digitalization and Building Information Modeling (BIM) in the Architectural, Engineering and Construction (AEC) are high. The high expectations are reflected in an increasing interest for the term business value of BIM. However, the practical and theoretical understanding of its content and perspective is characterized by rationalism and positivism commercially promoted by industry. This thesis aims to reflect on, problematize and extend the theoretical understanding of the content and perspective of the business value of BIM. Perceptions about business value of BIM, the associated challenges and costs and the role of the business of BIM in a wider socio-technical context are examined among Swedish and international AEC industry actors and a large Swedish public infrastructure client. To extend the understanding of the content and perspective of the business value of BIM, the rational and process-oriented theories on the business value of IT are combined with the more interpretive and hermeneutic socio-technical systems theory. A social and cognitive dimension is thus added to the understanding of the business value of BIM and business value of IT.  By combining the two research fields and contributing with the socio-technical perspective to the theoretical understanding of business value, this thesis contributes with theory development of the understanding of business value BIM and business value of IT.  For practitioners, the thesis shows the complex, multi-dimensional and challenging aspects of implementing BIM for business value. The journey of perspectives in this thesis from positivism towards increased interpretivism also sheds light on the implications of when different perspectives exert influence on a research field (hegemony) and wishes to provide a contrast and balance to the rational and positivistic perspectives in BIM research. It also wishes to inspire future BIM research to broaden the theoretical perspectives.

  • Xu, Annie
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Integration of an ERP System:: a case study onintegration challenges with Microsoft Dynamics AX2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Historically, system integration of ERP system and other existing IT systems within anorganization has always been a complex challenge, both technically and organizationally. Inmany cases, the budget for system integration corresponds 30-40% of the whole IT budget.Since system integration accounts for a large part of the cost during acquisitions andimplementation of an ERP system, companies are interested in the challenges that exist duringsystem integration, to simplify the integration process and hence reduce the costs. Tounderstand the challenges, a case study at Company X has been performed. The ERP systeminvestigated in the case study is Microsoft Dynamics AX.The purpose with this study is to investigate challenges that exist in large organizations duringsystem integration of ERP system and other IT systems that exist in the organization andthereby understand how integration can be developed in a more efficient way.The study entails an extensive literature study and two rounds of data collection throughqualitative interviews.The results showed that the challenges that exist at Company X are mainly organizational.Technical challenges coexist but they have a much less significant impact than theorganizational challenges. This can be explained by that there has been a heavier focus onsolving the technical related problems and maybe to some extent neglected the impactorganizational problems can have on system integration. Possible actions includes centralstrategy concerning how to work with Dynamics AX, it’s growth and future initiatives,policies and framework regarding working methods, increased authority and decision rights tothe group working with AX as well as minimize customizations and own development.

  • Tavakoli, Behrooz
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Ismail, Mohammadi
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Digital maturity within distributionA study within the Swedish retail industry2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The digital transformation is affecting every dimension of every business while the retailindustry is no exception. The changing expectations from the customer of today set increasedrequirements on distribution. Correspondingly, it seems that distribution is an area within whichdigital technologies can have major impact for retail companies. However, there is a lack ofpractical cases that demonstrate this impact in the Swedish market. As many retailers havestarted to integrate digital tools within their supply chains, different players have achieveddifferent levels of digital maturity in their distribution.The purpose of this research is to investigate the digital maturity level of retail companies withindistribution as well as their perception of digitalization alongside its impact on distributionprocesses. The method for data gathering consisted of qualitative interviews in combinationwith a questionnaire. The collected data in combination with theoretical research was used tofulfill the research purpose.The analysis revealed the digital maturity level within distribution for ten of Sweden’s largestretailers operating in different branches. All ten case companies were categorized as eitherAdopters or Collaborators. With respect to what literature have mentioned as benefits of digitaldistribution, the analysis further revealed the benefits that case companies have gained bydigital tools. Cost efficiency, traceability, delivery accuracy, improved lead time, shelfavailability, and increased free time in stores were the major benefits gained by digital tools, asdescribed by case companies.

  • STRÖMQVIST, DANIEL
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    DANIELSSON, FILIP DANIELSSON
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    Working proactive towards higher OTD: A case study at the operations department atABB GA Products, investigating the possibility toenhance a more proactive way of work towardshigher OTD.2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Purpose - The purpose of this study is to investigate and understand which significantparameters affect OTD within an ATO company, and furthermore develop a model which wouldenhance proactive work in order to achieve a higher OTD.Design/methodology/approach - The data is primarily of qualitative nature, employing semistructuredinterviews and workshop, with backup from quantitative production data. Anabductive approach was applied by iterating and aligning findings with relevant literature andtheory. These mixed methodologies created a triangulation of data, which through our analysishelp with the validation of our conclusions.Findings - Through our findings we can conclude that significant parameters which lowers OTDfor an ATO company can be found all through the supply chain. For this thesis and its model,parameters were chosen based on their ability to be quantified. For ABB GA Products, we found36 significant parameters as well as a systematic approach for an ATO company to iteratively gothrough them to investigate which orders are affected by which flags. Through this approach anATO company should be able to work more proactively towards higher OTD.Research limitations/implications - This thesis is conducted through a case study at ABB GAProducts only, which should be considered when using the results for further research.Practical implications - Specifies a logical scheme to classify risk of delayed orders.Originality/value - Advances theory in production and operations management regardingperformance measurement, towards a more proactive approach of measuring reactive KPI’s

  • Nilsson, Amanda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Economics.
    Alvfors, Oskar
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Economics.
    Säljares riskpreferenservid bostadsförsäljning2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    På grund av den kraftiga ökningen av bostadspriser i Stockholm har individer påmarknaden börjat uppvisa tveksamhet, både på ett psykologiskt och ekonomiskt plan, isamband med bostadsaffärer. För dessa individer kan beslut och ställningstaganden fåstora konsekvenser för privatekonomin och vara avgörande för en framtidabostadskarriär.Det för Sverige unika och komplexa budgivningssystemet, ”den öppna budgivningen”,involverar ett riskmoment för individer i stånd att sälja sin bostad. Det är därförintressant att utreda säljares riskpreferenser samt hur de väljer att agera i dessabeslutssituationer under risk. Beslutsfattande under risk, och inte minst riskaversion, ärett av litteraturen ofta berört område. Det finns dock begränsad forskning kring hurmotsvarande beteenden tar sig uttryck på bostadsmarknaden. Denna studie syftardärför till att utreda säljares riskpreferenser på Stockholms bostadsmarknad.Med grund i prospektteorin utformas en webbaserad enkätundersökning och intervjuermed fastighetsmäklare och säljare på bostadsmarknaden genomförs. Detta utgör ettempiriskt bidrag till forskningsområdet. Det empiriska materialet analyseras genom enmultipel regression samt sammanfattande statistik och kompletteras med en kvalitativanalys av intervjumaterialet.Studien fastslår att det finns indikativa beteenden för säljares riskaversion samt att detfinns samband mellan olika demografiska faktorer och individens nivå av riskaversion.Vidare belyses riskaversionens omfattande situationsberoende. Därtill applicerasprospektteorin samt teorin kring begränsad rationalitet, vilka fastslås utgöra ett robustförklarande teoretiskt ramverk i relation till beslutsfattande i ett bostadskontext.

  • Danial, Javani
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
    The Organisational Challenges of Implementing eHealth Services:: A Case Study on The Patient Self-Test Application in Centre for Rheumatology2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It is widely believed that eHealth will play a vital role in the development and shaping of healthcare systems in the twenty first century. However, despite all documented reports and benefits of eHealth technologies, many attempts to extend successful pilot projects have not sufficiently met promised results and to a large extent failed. The purpose of this study is to investigate the Centre for Rheumatology’s current implementation process of eHealth services in order to identify success factors and improvement areas. To reach the purpose, the research was delimitated to solely focus on the eHealth service Patient Self-Test and the implementation of it at the care unit.The research was conducted as a case study with a qualitative approach based on the notion of induction. The research process consisted of three major areas: pre-study, literature review and qualitative interviews. The pre-study was based on interviews with different actors within the health care industry in Sweden to provide an academic, political and business perspective of the research area. The literature review focused on the areas eHealth and change management and empirical data was gathered through qualitative interviews. Moreover, to have a tool for analysis, a research framework named 4 Seasons Model was developed.The results of the thesis indicate on a gap between how the literature advocates the implementation of transitional changes, and how it is currently done at Centre for Rheumatology’s. Based on an analysis from a 4 Seasons Model perspective, three success factors and seven improvement areas have been identified in Centre for Rhematology’s current implementation process of the Patient Self-Test.

  • Stetler, Fredrik
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Isolated magnetic field structures in the Saturn magnetosphere2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report’s primary focus is to use the data gathered by the Cassini satellite and analyzeits magnetic field data around Saturn. By looking for isolated changes in magneticfield values locations of potential plasmoids can be determined and examined. Theseso called plasmoids are pockets of higher density plasma ,associated with an increaseor decrease of the magnetic field strength, inside the magnetosheath, which may be importantfor the interaction between the solar wind plasma and the magnetosphere. Thestudy has been made over 7 years, from the beginning of 2010 to the end of 2016. Duringthis period a number of magnetic field structures have been found and documentedin this report, along with analyzing some of their properties such as their width andmagnetic field strength.

  • Roa Rodríguez, Rodrigo
    KTH, School of Computer Science and Communication (CSC).
    Tiling heuristics and evaluation metrics for treemaps with a target node aspect ratio2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Treemaps are a popular space-filling visualization of hierarchical data that maps an attribute of a datum, or a data aggregate, to a proportional amount of area. Assuming a rectangular treemap consisting of nested rectangles (also called tiles), there are multiple possible valid tiling arrangements.

    A common criterion for optimization is aspect ratio. Nevertheless, treemaps usually consist of multiple rectangles, so the aspect ratios need be aggregated.

    The basic definition of aspect ratio (width divided by height) cannot be meaningfully aggregated. Given this, a definition of aspect ratio that does not differentiate height from width was suggested. This definition allows for meaningful aggregation, but only as long as there are no large differences in the data distribution, and the target aspect ratio is 1:1.

    Originally, a target aspect ratio of 1:1 was deemed to be axiomatically ideal. Currently, perceptual studies have found an aspect ratio of 1:1 to lead to the largest area estimation error.

    However, with any other target this definition of aspect ratio cannot be meaningfully aggregated.

    This thesis suggests a correction that can be applied to the current metric and would allow it to be meaningfully aggregated even when there are large value differences in the data. Furthermore, both the uncorrected and corrected metrics can be generalized for any target (i.e. targets other than 1:1).

    Another issue with current evaluation techniques is that algorithm fitness is evaluated through Monte Carlo trials. In this method, synthetic data is generated and then aggregated to generate a single final result. However, tiling algorithm performance is dependant on data distribution, so a single aggregateresult cannot generalize overall performance. The alternative suggested in this thesis is visual cluster analysis, which should hold more general predictive power.All of the above is put into practice with an experiment. In the experiment, a new family of tiling algorithms, based on criteria derived from the results of the perceptual tests in literature,is compared to the most popular tiling algorithm, Squarify.

    The results confirm that there are indeed vast but consistent value fluctuations for different normal distributions. At least for a target aspect ratio of 1.5, the new proposed algorithms are shown to perform better than Squarify for most use cases in terms of aspect ratio.

  • Hübinette, Stina
    KTH, School of Computer Science and Communication (CSC).
    The true effects of programmatic display marketing: A study on how advertisers could make use of programmatic in the different stages of the customer journey.2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In digital marketing, display advertising has always been the largest revenue stream for publishers, and the biggest channel for advertisers to increase the traffic to their sites as well as getting better brand recognition. However, with the ever increasing spread of the smartphone and the continuously smarter machine learning of today, the industry has changed.   

    This study began with a hypothesis that since traditional display marketing evolved into programmatically bought display, the value of display advertising goes beyond branding and driving traffic to sites. Programmatic display advertising is intelligent display advertising that is bought programmatically based on algorithms and big data. The focus of this study was to analyze programmatic display campaigns, which are defined as marketing campaigns where the purchasing of publisher inventory is done by algorithms, with a set of conditions set up by the advertiser.

    The first step in answering the research question: “What value(s) in marketing does programmatic display campaigns bring in different stages of a company’s lifecycle and what should be expected from such campaigns in these different stages as well as in the different stages of the customer journey?” was to investigate how advertisers and experts value this type of advertisement.

    To reach the right customer, at the right time, with the right message, has long been the goal advertisers have with digital marketing. However, the way most advertisers go about doing this, is by using different channels to reach the customer at different stages of the customer journey. This study aims to prove that this way of doing digital marketing might not be the best one. In addition to using different channels for different purposes, could programmatic potentially be used in different ways in order to improve marketing?

    By compiling information and data from previous studies done in the research area, and real programmatic advertising campaigns, this study produced a framework of recommendations for how advertisers should segment their display campaigns in order to get more value from them.

    This research is done in collaboration with experts and advertisers in the Schibsted Media Group. My hopes are that advertisers in the group will either read this study or listen to my presentation and re-evaluate how the framework in this study could help them rethink the way they structure their display campaigns and also rethink how the channel should be valued.

    The findings of this study is that yes, it is possible to use programmatic for more than just branding or for the purpose of driving traffic. 

  • Li, Bing
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Månsson, Daniel
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Impact evaluation of conducted UWB transients on loads in power-line networks2017In: Advances in Radio Science - Kleinheubacher Berichte, ISSN 1684-9965, E-ISSN 1684-9973Article in journal (Refereed)
  • Bergström, Amanda
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Bengtsson, Olivia
    KTH, School of Computer Science and Communication (CSC).
    Låter du andra styra din identitet på Facebook?2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Social Networking Sites (SNS) are growing tremendously, both in terms of number of users and the time spent using social media and SNS. Facebook is the SNS with the most users in the world, and in Sweden 82% of the population in the ages 16 and 25 years visit the site daily. Social media have great impact on people’s lives and also impact the way young people form their identity.

    In this paper we have conducted a number of interviews to answer the question “What feeling are raised among Facebook users between 20-25 years in Sweden when someone else affects their profile through timeline posts and tags?”.

    The study shows that the feelings differs between the participants. The majority were positive to including friends in the social identity on Facebook. However, they also wanted to stay anonymous to keep control of one's identity presented online.

  • Wiklund, Elvira
    KTH, School of Computer Science and Communication (CSC).
    Improving a company's social media strategy: A study based on a competitive analysis2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study started off during the spring of 2017 and had the goal of with the aid of a competitive analysis create a new social media strategy for the company Spree. During the last years, digitalization has grown increasingly and has become more integrated in our society. Together with the digitalization, the use of social medias has increased, both for personal use and for business use. For companies, the use of social medias is still relatively new, so a designed and developed social media strategy can be crucial for a company to reach out in the right way and to the right target group.

    This study show that a well-designed social media strategy can be created with the aid of a competitive analysis together with a deeper analysis of the company’s own social medias. The analysis of the company’s own social medias helps to illustrate the current flaws that exists, while the competitive analysis assist in finding relationships that can help the company get an apprehension of what their main focus should be on. 

  • Berglund, Erik
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    LQR and MPC control of a simulated data center2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of the largest contributions to a data center’s power usage is its cooling system. To decrease the energy usage of the cooling system, an automatic control scheme that adapts the capacity of the cooling units is needed. In this master thesis, a Simulink model of a data center is developed, along with several LQR and one MPC controller. The controllers control the outlet temperature and volumetric airflow of two CRAH units in the simulated data center. Simulations are performed in which the controllers are judged based on their estimated energy usage and how often the server temperatures in the data center exceed 35°C. Based on the experimental results, recommendations are made regarding what kinds of controllers to investigate in ABB’s further research.

  • Edman, Edman
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Radar target classification using Support Vector Machines and Mel Frequency Cepstral Coefficients2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In radar applications, there are often times when one does not only want to know that there is a target that reflecting the out sent signals but also what kind of target that reflecting these signals. This project investigates the possibilities to from raw radar data transform reflected signals and take use of human perception, in particular our hearing, and by a machine learning approach where patterns and characteristics in data are used to answer the earlier mentioned question. More specific the investigation treats two kinds of targets that are fairly comparable namely smaller Unmanned Aerial Vehicles (UAV) and Birds. By extracting complex valued radar video so called I/Q data generated by these targets using signal processing techniques and transform this data to a real signals and after this transform the signals to audible signals. A feature set commonly used in speech recognition namely Mel Frequency Cepstral Coefficients are used two describe these signals together with two Support Vector Machine classification models. The two models where tested with an independent test set and the linear model achieved a overall prediction accuracy 93.33 %. Individually the prediction resulted in 93.33 % correct classification on the UAV and 93.33 % on the birds. Secondly a radial basis model with a overall prediction accuracy of 98.33 % where achieved. Individually the prediction resulted in 100% correct classification on the UAV and 96.76 % on the birds. The project is partly done in collaboration with J. Clemedson [2] where the focus is, as mentioned earlier, to transform the signals to audible signals.

  • Andersson, Karl
    KTH, School of Computer Science and Communication (CSC).
    Manipulating Control-Display Ratios in Room-Scale Virtual Reality2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study examined how reduced control-display ratios on motion-tracked handheld controllers in virtual reality affected user immersion and sense of control. 24 participants played a puzzle game in virtual reality using one of three control-display ratios: one normal, and two that were reduced using the “Go-Go” technique. Results indicate that the control-display ratio can be reduced drastically while retaining user immersion and sense of control, but that the effectiveness of this seems to differ between individuals and is heavily influenced by previous experiences. Even so, these results could be of use for future virtual reality interaction designers as well as researchers studying the senses of vision and proprioception. 

  • Lönnerberg, Mattias
    KTH, School of Computer Science and Communication (CSC).
    Cutting Tetrahedra: Affordances and Limitations of Using Virtual Reality Visualization for Tetrahedral Cutting2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Finite element method researchers aim to create algorithms for optimally cutting complex 3D shapes into several tetrahedra for computational efficiency in simulations. It is difficult to create a mental representation of the 3D shapes as they increase in complexity. Our hypothesis is that a virtual reality (VR) visualization could help with creating this mental 3D representation. In this thesis, a desktop tool using a 2D monitor and a virtual reality tool were compared in a controlled within-subject user study. The findings show that VR gave a better understanding of the 3D objects. Participants reported VR to be more intuitive and enjoyable than the 2D monitor. However, it did not improve the time it took to complete the study tasks and, although it made the users perceive that they were more accurate, the observational data suggests that more accurate cuts were made using the desktop tool.

  • Steier, Martin
    KTH, School of Computer Science and Communication (CSC).
    Discovering plagiarism in entry level programming assignments2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Plagiarism in programming assignments has been a problem for a long time, and while the schools try to stop it, it is an ever ongoing game of cat and mouse between students and the schools. When students find new ways to hide their plagiarism, others develop new tools to find it again. This thesis looks specifically at plagiarism in entry level coding assignments, where the code is usually much simpler, and if it is possible to use the structure of the program code to detect plagiarism. The structural properties chosen is the abstract syntax tree for the code along with the codes call graph. The syntax tree contains the programs general structure and the call graphs are used in an attempt to find plagiarism where plagiarized code has been split up in smaller parts. For comparison a well established algorithm called MOSS is used. The results shows that the abstract syntax tree and call graph can be used to identify plagiarism, but it seems it is not worth the additional effort needed to use algorithms based on program structure, as it seems the plagiarism done for these assignments is quite simplistic. Additional research should instead be done to find out more on how students actually cheat in these entry level assignments and develop methods to counter those specifically.

  • Lindahl, Elin
    KTH, School of Computer Science and Communication (CSC).
    A qualitative examination of lead scoring in B2B marketing automation, with a recommendation for its practice.2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Digital marketing has become an important part for companies in the process of attracting new customers. The digitalisation has led to substantial changes in the ways consumers and businesses search for information and do their research before making a purchase. A major shift has been observed regarding how digital communication influences the purchasing decision within the B2B sector.

    The purpose of this research project was to examine lead scoring in the perspective of B2B marketing automation, and to investigate how lead scoring can contribute to a more efficient and effective marketing process for Visma Advantage. The aim was to develop a recommendation for an optimal lead scoring model for Visma Advantage and which marketing actions that are suitable for the different lead score values.

    The result shows that there can be several ways of an optimal use of a lead scoring model for Visma Advantage. The result also presents a completed lead engagement scorecard and lead profile scorecard, together with a lead score matrix that specifies the thresholds for each lead score value. In addition to that, relevant marketing actions for each lead score value in the model is presented in the result. 

  • Johansson Sjöwall, Martin
    KTH, School of Computer Science and Communication (CSC).
    Exploring the search functionalities on a website designed for children2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The usage of Internet has increased among children. Much of that use comes from watching videos and playing games. There are a few services that cater to this need and Barnkanalen is one of them. However, in order for the service to be usable to children it needs to be adapted for them and content needs to be easily available. Children with no or little reading ability and writing skills need extra attention since they simply can not type correctly what they are searching for into a search field. This paper explores children’s preferred search strategies and what problems they experience on one of the major websites designed for children by conducting a user study.

    The user study was based upon a usability evaluation method called Constructive Interaction, where the children collaborated in pairs to solve search related tasks given to them. It was conducted at an after-school center in Bromma, Stockholm. 19 children aged 6-8 participated.

    The results indicate that the computer user interface and search functionalities of Barnkanalen need some improvements. The children with more developed spelling skills often have no problems, finding what they are supposed to find, when they know the title of the show. When the children did not have the knowledge of the titles or could not spell them they experienced some difficulties in finding what they were looking for. Most would browse the page, scrolling through the content being presented in horizontal lists. Some children got stuck in repetitive search loops; some were not paying enough attention and missed what they were looking for when it showed up on the screen. The children also had a hard time clicking on what they wanted to click at. Only four children had prior experience of visiting Barnkanalen on a computer but almost all of the children had experience using Barnkanalen on tablets or smartphones. The results led to recommendations on how to improve the site. For example, show titles in English should be allowed to be spelled phonetically, certain buttons need to be bigger, making Barnplay the start page of Barnkanalen and a virtual assistant is proposed. 

  • Mishra, Shashank
    KTH, School of Computer Science and Communication (CSC).
    Analysis of test coverage metrics in a business critical setup2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Test coverage is an important parameter of analyzing how well the product is being tested in any domain within the IT industry. Unit testing is one of the important processes that have gained even more popularity with the rise in Test driven development (TDD) culture.This degree project, conducted at NASDAQ Technology AB, analyzes the existing unit tests in one of the products, and compares various coverage models in terms of quality. Further, the study examines the factors that affect code coverage, presents the best practices for unit testing, and a proven test process used in a real world project.To conclude, recommendations are given to NASDAQ based on the findings of this study and industry standards.

  • Ceylan, Ciwan
    KTH, School of Computer Science and Communication (CSC).
    Conditional Noise-Contrastive Estimation: With Application to Natural Image Statistics2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Unnormalised parametric models are an important class of probabilistic models which are difficult to estimate. The models are important since they occur in many different areas of application, e.g. in modelling of natural images, natural language and associative memory. However, standard maximum likelihood estimation is not applicable to unnormalised models, so alternative methods are required.

    Noise-contrastive estimation (NCE) has been proposed as an effective estimation method for unnormalised models. The basic idea is to transform the unsupervised estimation problem into a supervised classification problem. The parameters of the unnormalised model are learned by training the model to differentiate the given data samples from generated noise samples. However, the choice of the noise distribution has been left open to the user, and as the performance of the estimation may be sensitive to this choice, it is desirable for it to be automated.

    In this thesis, the ambiguity in the choice of the noise distribution is addressed by presenting the previously unpublished conditional noise-contrastive estimation (CNCE) method. Like NCE, CNCE estimates unnormalised models by classifying data and noise samples. However, the choice of noise distribution is partly automated via the use of a conditional noise distribution that is dependent on the data. In addition to introducing the core theory for CNCE, the method is empirically validated on data and models where the ground truth is known. Furthermore, CNCE is applied to natural image data to show its applicability in a realistic application.

  • Strigér, Amanda
    KTH, School of Computer Science and Communication (CSC).
    End-to-End Trainable Chatbot for Restaurant Recommendations2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Task-oriented chatbots can be used to automate a specific task, such as finding a restaurant and making a reservation. Implementing such a conversational system can be difficult, requiring domain knowledge and handcrafted rules. The focus of this thesis was to evaluate the possibility of using a neural network-based model to create an end-to-end trainable chatbot that can automate a restaurant reservation service.

    For this purpose, a sequence-to-sequence model was implemented and trained on dialog data. The strengths and limitations of the system were evaluated and the prediction accuracy of the system was compared against several baselines.

    With our relatively simple model, we were able to achieve results comparable to the most advanced baseline model. The evaluation has shown some promising strengths of the system but also significant flaws that cannot be overlooked.

    The current model cannot be used as a standalone system to successfully conduct full conversations with the goal of making a restaurant reservation. The review has, however, contributed with a thorough examination of the current system, and shown where future work ought to be focused.

  • Wong, Mark
    KTH, School of Computer Science and Communication (CSC).
    Comparison of heat maps showing residence price generated using interpolation methods2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this report we attempt to provide insights in how interpolation can be used for creating heat maps showing residence prices for different residence markets in Sweden. More specifically, three interpolation methods are implemented and are then used on three Swedish residence markets. These three residence markets are of varying characteristics such as size and residence type. Data of residence sales and the physical definitions of the residence markets were collected. As residence sales are never identical, residence sales were preprocessed to make them comparable. For comparison, a so-called external predictor was used as an extra parameter for the interpolation method. In this report, distance to nearest public transportation was used as an external predictor.

    The interpolated heat maps were compared and evaluated using both quantitative and qualitative approaches. Results show that each interpolation method has its own strengths and weaknesses, and that using an external predictor results in better heat maps compared to only using residence price as predictor.

    Kriging was found to be the most robust method and consistently resulted in the best interpolated heat maps for all residence markets. On the other hand, it was also the most time-consuming interpolation method.

  • Munasinghe, Aroshine
    KTH, School of Computer Science and Communication (CSC).
    A Culture-Centered Design Approach to Improve a User Interface for Migrants2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A web application known as the Virtual Volunteer has been developed by IBM, the International Federation Red Cross and the Red Crescent Movement. The aim of this application is to extend support to migrants beyond the physical help they receive. The application is also a resource for volunteers who want to help migrants. This paper explores how a culture-centered design approach can help to improve a user interface and enhance the usability for a global audience using Virtual Volunteer as a design case. By conducting multiple interviews and task completion tests with verbal protocols, the results present two independent redesigned prototypes. 

    The culture-centered design approach yielded valuable feedback and data from the migrants that would not have been possible to collect from a more traditional approach like the one employed when creating the Virtual Volunteer in the first place. The results also revealed that all functions in the application were not clearly understandable for the migrants as they were for the Swedish volunteers. The overall results of the design case shows that a culture-centered design approach together with common usability methods are efficient to use when developing user interfaces for migrants and volunteers. 

  • Westerlund, Kristian
    et al.
    KTH, School of Electrical Engineering (EES).
    Carneheim, Stina
    KTH, School of Electrical Engineering (EES).
    Error Analysis for Disconnectors of Type ASEA NUB 420/2000 and ASEA NUB B 245/40002017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An important part in developing the power gridis maintaining the older parts of the system. This reportexamines the reliability of disconnectors ASEA NUB/NUB-Bin the electrical power grid in order for maintenance to beoptimised. Different mathematical models were used to analyseerror statistics of the disconnectors. This is used to obtain animage of the disconnectors life cycle. The report concludes thatASEA NUB 420/2000 have a life expectancy of 20 years and NUBB245/4000 are expected to last for 30 years. It also concludes thatthe amount of data used in this project is insufficient and does notgive a correct representation of the lifespan of the disconnectors.

  • Wall, Thomas
    KTH, School of Electrical Engineering (EES).
    Development of the Winding Geometry for an Efficient Wave Power Generator2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A method for twisting a stranded cable in orderto reduce losses due to circulating currents is investigated. Atheoretical model connecting the voltages over individual strandsto the magnetic flux through the cable is presented. A modelsimplifying the geometry of the cable is developed. Twistingsolutions are investigated both analytically and through the use ofa computer model for a simplified magnetic field. The sensitivityof these solutions to variation in the magnetic field is analysedfor a 40 strand cable. The limitations of the model and problemsassociated with applying it to a cable of 110 strands are discussed.

  • Wahlqvist, Kristian
    et al.
    KTH, School of Electrical Engineering (EES).
    Caesar, Felix
    KTH, School of Electrical Engineering (EES).
    Automatic Measurement Setup for Characterization of On-Chip Tunable Grating Couplers2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Grating couplers are used for coupling betweenoptical fibers and on-chip silicon photonics waveguides. Efficientfiber-to-chip coupling is elemental in in the development ofphotonics, making the process of evaluating new grating couplerdesigns vital. The idea of tunable grating couplers is to useparallel plate actuation to manipulate the power distribution ofthe coupled light, thus affecting coupling efficiency and openingfor implementation of applications such as laser scanning andranging on chip. As new grating coupler designs are developed,they need to be evaluated through experiments to determinetheir behavior. Hence, there is a need to develop a reliable andrepeatable method for characterization. We have successfullydesigned and implemented an automated measurement setup thatcan be used to characterize tunable grating couplers. We havealso showed that tunable grating couplers can in fact be used tooptimize coupling efficiency between optical fibers and on-chipsilicon photonics waveguides.

  • Tuul, Viktor
    et al.
    KTH, School of Electrical Engineering (EES).
    Dahlberg, John
    KTH, School of Electrical Engineering (EES).
    Intelligent Traffic Intersection Management Using Motion Planning for Autonomous Vehicles2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With the increasing advances in the field of autonomousvehicles it is alluring to ask if a possible vehicularparadigm shift is in the near future. Maximizing road capacitywith Intelligent Traffic Intersections that communicate withautonomous vehicles could become a reality, where the needfor traffic lights and stop signs is excluded. In this paper, anAutonomous Intersection Management system is introduced thatutilizes trajectory-based prioritization and motion planning techniquesto manage traffic in an orthogonal single lane four-wayintersection. The developed system reduces the need for vehiclesto slow down or even stop before intersections, contrariwise, itlets all vehicles enter the intersection at the highest allowed speed.The proposed solution is shown to increase the capacity of intersectionscompared with contemporary intersections managedwith traffic lights.

  • Suliman, Ayman
    et al.
    KTH, School of Electrical Engineering (EES).
    Bäverlind, Joakim
    KTH, School of Electrical Engineering (EES).
    Experiments With Four Pattern Recognition Algorithms2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A big part of computer vision concerns the issue ofhow well images can be classified into their corresponding classes.Image classification is a big part of reducing the gap betweenhuman and AI performance. Images are classified by first usinga dataset of images together with their given classifications totrain the system with machine learning. This can then be usedon images without any classification to test and see how well thealgorithm can classify an unknown image. However, this can bedone in many different ways and methods. The aim of the projectis to compare the performance of four algorithms: MultivariateGaussian Distribution Model, Least Square Regression (LS),Kernel Regression (KR) and Extreme Learning Machine (ELM).By using three different databases, the performance of the fouralgorithms varied. The algorithms were tested by reducing thedimensions of the images it was processing in order to analyzehow well the algorithms worked with different quality of images.The results show that some algorithms work best when moreimages are used for training, while some algorithms strugglewith more images and/or classes. This report concluded that theaccuracy of the algorithms varied depending on the structureof the database. By analyzing the structure of the database,the optimal classification algorithm can be chosen for bestperformance.

  • Stiff, Harald
    KTH, School of Electrical Engineering (EES).
    Stem Cell Classification With Convolutional Neural Networks2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this bachelor thesis project, the problem of imageclassification with convolutional neural networks is considered.In several fields of biology, automatized cell detection is a helpfultool for facilitating the process of cellular analysis. This reportanswers the question whether a computer program can tell if animage contains muscle stem cells or not. Analogously to the neuronsof the human brain, the creation of such a program involvestraining thousands of mathematically modeled artificial neuronsto maximize the likelihood of producing correct classifications.This report covers how such a network is implemented and showshow its performance dependens on the network’s dimensions. It isrevealed that a neural network indeed can replace and speed upthe manual process of classifying images. With an image datasetof cells, the best performing networks manage to classify imageswith an accuracy of up to 90%.

  • Solhall, Axel
    et al.
    KTH, School of Electrical Engineering (EES).
    Guéry, Edvin
    KTH, School of Electrical Engineering (EES).
    Coordination of Wind Power and Hydro Power2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The goal of this project was to calculate howmuch wind power could be balanced with hydro power in ourdesignated area consisting of five hydro power stations, fourvillages which consume power, possible locations for windpower and one connection to the national grid. To achieve this asimulation model was constructed in the GAMS software withthe goal of achieving the maximum profit from the hydro powerplants by considering electricity prices, inflow of water, thephysical construction of the power plants and the time of year.When this was achieved, restriction for the maximumtransmission load on the power grid was added as well as localwind power production as to simulate the implementation ofnew power sources on an old system and power grid. This wouldresult in a maximum income in SEK as well as the most windpower which could be maintained and balanced by thedesignated system. This project shows how to find the optimalway to use hydro power and wind power as well as how theintegration between different sources of electricity productioncould work, which is vital for a future powered by renewableenergy and will help towards lowering emissions.

  • Rozenbeek, David
    et al.
    KTH, School of Electrical Engineering (EES).
    von Keyserlingk, Erik
    KTH, School of Electrical Engineering (EES).
    Recovery and Flight Data Recording System for Free Falling Units Ejected From Sounding Rocket2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aurora phenomena is a remarkable sight, commonlyrefereed to as polar or northern lights. A previous spaceexperiment SPIDER was dedicated to measure electric fieldsand characterize plasma properties in the aurora, using tenFree Falling Units (FFU) ejected from a sounding rocket. Theexperiment was successful but some problems arose. A newexperiment WOLF is committed to solve those problems andre-doing the experiment.This paper describes the process of developing a new recoveryand flight data recording system for the WOLF experiment, usingheritage from the previous SPIDER experiment. The developedsystem will be used on the upcoming WOLF experiment rocketlaunch in February 2018.The thesis analyzed hardware problems in previous design toimprove robustness and reliability, identified obsolete componentsfor replacement and added functionality for the new system. Anew hardware system was developed with schematics and PCBlayout ready for manufacturing. Also, plans for the firmware wasestablished. In the paper it is discussed about topics that shouldbe considered in the future work in developing the system andhow the system can be re-purposed for similar experiment in thefuture.

  • Radesjö, Fanny
    KTH, School of Electrical Engineering (EES).
    Parameter Identification and Information Modeling of Gas Turbine Models for Power System Simulations2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the future renewable generation sources will have toco-exist with traditional generation sources that can overcome theirlimitations in providing secure power supply to society, such as gasturbines.In this project we proposed to substitute a simple model of a gasturbine by a detailed model to simulate the turbine´s behavior in areal system. Parameter identification of a simple gas turbine modelwas performed based on measurements from a detailed model. Bythis, the project contributes to a library of electric grid componentmodels. The library is meant to allow operators and engineers topredict the system behavior by simulations. This can facilitate toanticipate possible instability in the grid and thereby contribute tothe transition to the Smart Grid.Further, another gas turbine model was in the Modelica languagewas represented using the Unified Modeling Language (UML). Thisis a standard form of modelling that simplifies exchange of modelinformation between project groups.

  • Pousette, Marcus
    KTH, School of Electrical Engineering (EES).
    3D Mapping of Deuterium for Fusion Applications2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this paper deuterium abundances in plasmaenclosing wall materials are analyzed and visualized. The aim isto improve and find new ways of presenting counting statistics.A continuous extension of the sample variance is introducedto incorporate depth resolution when visualizing concentrationas function of depth in a continuous manner. Some ideas ofdesigning measurements of deuterium are discussed, in particularchoosing ion beam energies. By using multiple energies of thehelium-3 beam instead of one, more detector data can be used.With diverse ways of visualizing concentrations derived fromoptimal detector data, one can conveniently quantify deuteriumconcentrations in a surface.

  • Olsson, Axel
    et al.
    KTH, School of Electrical Engineering (EES).
    ter Vehn, Anton
    KTH, School of Electrical Engineering (EES).
    Performance of Electrohydrodynamic Thrusters When Stacked2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Electrohydrodynamic thrusters or ion crafts arenew potential alternatives to conventional engines. They usehigh voltage to produce a thrust in the form of an airflow,also called an ion wind. The problem when implementing thesethrusters is that they are not efficient enough to compete withconventional engines. The focus of this report lies on how stackingaffects efficiency and performance, depending on the number ofthrusters used in each stack and how they are combined. Thiswas accomplished by placing thrusters on top of each other indifferent orders and studying how the change in current andvoltage affected the flow of air. From this it was possible todetermine that the performance of multiple thrusters in a stackcould produce a higher flow of air at a greater efficiency thana single thruster, as the total efficiency increased by the squareroot of the number of stacked thrusters. At a potential differenceof 3850 V the efficiency increased from 0.08 ppm to 0.47 ppmwhen stacking 1 to 11 thrusters.

  • Norrsjö, Viktor
    et al.
    KTH, School of Electrical Engineering (EES).
    Stenberg, Viktor
    KTH, School of Electrical Engineering (EES).
    PID Controllers for Autonomous Vehicle Path Following2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Autonomous vehicles are set to create a paradigmshift. Everyone could relax on their way to work and no accidentsdue to falling asleep behind the wheel would occur. For this tohappen the autonomous vehicle requires among many differentcomponents, a lane following system. In this paper such asystem is developed. First a mathematical model that describea vehicles behaviour is derived. Then a regulator structure withcontrollers and other components is developed. Finally the systemis implemented as a complete simulator that simulates the movingvehicle. Several different scenarios are tested and the performanceof the system is evaluated. A working simulator is achieved witha vehicle following the predefined path with little deviation, thesystems behaviour is also smooth. It is concluded that the proposedsolution is sufficient for moderates vehicle speeds, but at higherspeeds the mathematical model will not be accurate and theperformance of the system will be insufficient.

  • Nordin, Joakim
    et al.
    KTH, School of Electrical Engineering (EES).
    Rågmark, Johan
    KTH, School of Electrical Engineering (EES).
    Grid Capacity and Upgrade Costs2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this study the incorporation of a larger wind powerpark in an electrical system is studied. The study is based ona simplified version of an existing grid in J¨amtland, a provincein Sweden, and aims to analyse how to best integrate the windpower regarding geographical, economical and system stabilityfactors. The base system consists of five hydro power plants,four cities, four possible connections of wind power parks and aconnection to the national grid. The study is based on numericalanalysis in MATLAB using data sets of wind strength, powerconsumption in the cities and generation from hydro power plantsin the area. Four days, each representing a season, are consideredand compared to give an insight to how the wind power couldaffect the system during a year. It is shown that wind power canbe integrated in J¨amtland’s grid without affecting the systemnoticeably if building a grid based on 220 kV. For a 130 kV gridthe voltage level instability and losses are significantly increased.With the 220 kV system the voltage variations from the windpowers irregular production are heavily suppressed and insteadthe losses from increased currents becomes the restricting factor.When comparing locations for wind power parks it is shown thatit is more preferable with the wind parks located closer to thecenter of the system where the main consumption lies.

  • Nobliá, Matilda
    et al.
    KTH, School of Electrical Engineering (EES).
    Ryan, Christian
    KTH, School of Electrical Engineering (EES).
    Contamination Event Detection in Water Distribution Systems2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In any society, making sure that its citizens havea clean water supply is a fundamental issue. By modernizingthe way water distribution systems (WDSs) are monitored andcontrolled, the impact of contamination can be maintained andminimized. By using sensors that monitor relevant physicalparameters, a system that detects contamination and limitspopulation exposure can be designed. To achieve this, the workpresented in this report is focused on three main topics.Firstly, parameters for determining water quality are examined.This is the basis for choosing relevant sensors. Secondly,a study of contamination event detection (CED) is presented, inparticular a method to determine whether water is contaminatedor not based on sensor measurements is proposed. This iscompleted through the use of binary hypothesis testing as wellas examining existing sensors. Thirdly, the problem of optimalsensor placement in a WDS is studied. In extension, a greedyalgorithm is implemented to optimally place sensors in a modelof real-world network.

  • Morast, Embla
    et al.
    KTH, School of Electrical Engineering (EES).
    Svantesson, Einar
    KTH, School of Electrical Engineering (EES).
    Efficiency of a Time-of-Flight Detection System for Analysis of Wall Material From Controlled Fusion Devices2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Time-of-flight elastic recoil detection analysis (ToFERDA)is a method for material analysis which has provenadvantageous when examining wall samples from fusion devicesas well as for tracking tracer isotopes such as deuterium, oxygen-18 and nitrogen-15. When ToF-ERDA data is processed tocalculate the composition of a material, the detection efficiencyis used to compensate for the lower detection rate of lighterelements. The aim of this project is to examine how the efficiencyof the time-of-flight detector in a ToF-ERDA experimental setupdepends on its settings and determine efficiency parameters touse when producing atomic composition depth profiles with ToFERDA.Experiments were performed at the Tandem Laboratoryin Uppsala. The outcome is a suggested set of changes toexperimental settings and a four-parameter fit to measureddetection efficiencies for efficiency compensation.

  • Mayh, Ahmed
    et al.
    KTH, School of Electrical Engineering (EES).
    Sonono, Tofik
    KTH, School of Electrical Engineering (EES).
    Study on Energy Consumption of a Turning Vehicle With Torque Vectoring and Four-Wheel Steering2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy is a limited resource, and as such it isnecessary to find ways to decrease the energy consumptionwherever possible. In this paper, the energy consumption of avehicle with a drive-by-wire system is observed. The drive-bywiresystem includes individual wheel steering and individualtorque feed to each tire. In order to generate results, a bicyclemodel is created in Simulink. This paper focuses on measuringthe energy consumption in terms of energy losses due to tireslip. The simulations are carried out in a systematic mannerwith predetermined configurations. These configurations definehow the vehicle is being steered, i.e., using a combination ofindividual wheel steering and torque vectoring. The results fromthe simulations show that the energy consumption is in factaffected when using different configurations in a drive-by-wiresystem. A result shows that it is possible to save 7% of energyin a certain turn scenario.

  • Manheij, Freddie
    KTH, School of Electrical Engineering (EES).
    Automated Analysis of Spider Silk Images2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Spider silk is a fascinating material with manyinteresting properties. Silk has many applications, but there areassociated challenges with producing it using spiders. Researchis done in order to find a way to create synthetic spider silkstructures using super hydrophobic surfaces. After this processit is important to evaluate the silk growth on the surface. Thishas to be done by taking images and the task for this projectis to develop a program that is capable of analyse them. Toevaluate the surface, images are taken using a scanning electronmicroscope (SEM) or a fluorescence microscope. Then the imagesare analysed using the program. The program analyses theimages using different methods involving contrast comparisonin order to accomplish the objective. The result is a programwritten in Matlab that is able to detect the size and direction ofthe nanowires on the surface.

  • Lönnroth, Viktor
    et al.
    KTH, School of Electrical Engineering (EES).
    Arleklint, Tomas
    KTH, School of Electrical Engineering (EES).
    Stator Core Design for a Linear Transversive Flux Machine2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wave power is not an energy source takenadvantage of partly due to the lack of effective generatorsfor slow speeds. There is an ongoing project at the RoyalInstitute of Technology in Sweden where a transversive fluxmachine specialised for slow speeds is being developed.This paper aims to design the core of this machine toachieve high efficiency and low cost. The basic design ispresented along with the approach to the different aspectsof the manufacturing. After examining possible losses thesehave been bypassed or minimised using various methods.If this is not done properly, the losses will be too severe forthe machine to prove useful. A study of the results showthat a very high efficiency will be achieved, way superiorto that of currently existing wave power generators.