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  • Falquier, Rene
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Flight Dynamics.
    Longitudinal Flight Mechanics of Paraglider Systems2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project outlines a cost-effective numerical simulation method for the analysis of the longitudinal mechanics of paraglider systems. It is built on static stability methods for the analyses of low subsonic aircraft, non-linear lifting line methods for aerodynamic parameterization, and frequency domain analysis methods derived from system theory. Paragliders possess a glide polar in the range of ≈ 25-60 km.h−1 and display underdamped dynamic responses dominated by a long-period mode. The simulation results for performance and dynamic response are qualitatively valid relative to experimental data and in the same order of magnitude.

  • Ask, Jacob
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Space Technology.
    Selected Trends and Space Technologies Expected to Shape the Next Decade of SSC Services2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Since the early 2000s the space industry has undergone significant changes such as the advent of reusable launch vehicles and an increase of commercial opportunities. This new space age is characterized by a dynamic entrepreneurial climate, lowered barriers to access space and the emergence of new markets. New business models are being developed by many actors and the merging of space and other sectors continues, facilitating innovative and disruptive opportunities. Already established companies are adapting in various ways as efforts to stay relevant are gaining attention. The previous pace of development that was exclusively determined by governmental programs are now largely set by private and commercial ventures. Relating to all trends, new technologies and driving forces in the space industry is no trivial matter. By analyzing and examining identified trends and technologies the author has attempted to discern those that will have a significant impact on the industrial environment during the next decade. Market assessments have been summarized and interviews have been carried out. Discussions and conclusions relating to the services provided by the Swedish Space Corporation are presented. This report is intended to update the reader on the current status of the space industry, introduce concepts and provide relevant commentary on many important trends.

  • Brenes Brenes, Rebeca
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Hydropower Modelling of Continental Europe Using EMPS2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Flexible hydropower plays a vital role when integrating large shares of variablerenewable generation in the power system. This project proposes a method forcreating a stochastic model for hydropower in Continental Europe using EMPS, apower market simulator software that specialises on hydrothermal power systems.The model is intended to be used in a power market analysis context, to assess thehydropower behaviour in Continental Europe in the medium and long term.The first step to create the model was to gather data from multiple sources regardinghydropower stations and reservoirs located in Continental Europe. The gathereddata was built and unified into a geographical information system to provide visualanalysis and facilitate performing of different operations and algorithms. Thecountries under study were split into different areas depending on the water basinsand other location factors. Representative inflow series were created for each area,and these were fed directly into EMPS. The stations and reservoirs were aggregatedper area and the inputs required by EMPS were calculated using a model based onhistorical data and an optimisation process.The model provides results for 45 different weather scenarios. The hydropowergeneration and reservoir content for each country were validated using historicaldata. In general, the results obtained provide a satisfactory representation of thehydropower in the region under study. Fine tuning is still required to improve theresults, but this project successfully provides a solid method to create the core ofthe stochastic hydropower model of Continental Europe in EMPS.

  • Barra, Stefano
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Functional Testing of the Electrical Power System of the MIST Satellite2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Electrical Power System is the key subsystem for the survival of the satellite.It not only supplies power to the satellite by keeping the battery adequatelycharged, but it also provides crucial fault detection and recovery functions.The target of this thesis work is to characterize and test all the functionalitiesof the EPS of the MIST satellite in realistic operational conditions through theimplementation of hardware and software simulators. Such a comprehensiveframework is based on a MATLAB software, the MIST flight hardware, aswell as Solar Panel Simulators and Arduino-based dummy loads created byprevious students in the project. These tools are used to integrate all theseelements into an easy-to-use simulation environment that very closely mimicsconditions in actual orbital flight and that can be used as a model for suchsimulations in similar satellite projects. The purpose of the simulations in thisenvironment is to verify that the planned flight profile of the satellite is correctand safe, especially from a power subsystem point of view.

  • Tamadon, Nahal
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Utilizing Privately Owned Flexibilities in the German Distribution System: Technical and Regulatory Framework2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This Master’s thesis project aims to define the technical and regulatory framework of asystem flexibility service utilizing distributed flexibilities connected to the low-voltage (LV)level. The flexibility service outlined here is local balancing, with the purpose of increasing theload-generation balance in LV networks using thermostatically controlled loads and ElectricalEnergy Storage (EES) devices. The thesis is performed at Avacon Netz GmbH, a GermanDSO, as part of the German demo for project InterFlex.The first part of the thesis encompasses the technical framework of local balancing. For thispurpose, day-ahead scheduling algorithms for heat pumps and EES devices are proposed toincrease the local consumption of distributed generation, and thereby decrease the reversepower flow and load peaks. Two scheduling algorithms are proposed in this thesis, one basedon numerical methods and one on optimization. The proposed algorithms are simulated fornine LV-networks in Avacon Netz’ grid area. The simulation results show that by utilizing allthe residential heat pumps and EES devices, the load peaks and the peak reverse flow can bereduced by up to 21.30% and 37.30% respectively.The commercial and regulatory framework of local balancing are analyzed in the second part ofthe thesis. The said service can be traded either using market-based mechanisms, or throughbilateral contracts between the DSO and the flexibility providers. Utilization of distributedflexibilities through the DSO has been vaguely mentioned in the German Energy Industry Act.The contractual framework and level of load interference has yet to be explicitly defined. Themarket-based trading is also analyzed in Part II, proposing a local semi-competitive marketfor flexibility services. Unlike flexibility services such as voltage or frequency control, localbalancing does not require a high level of DSO-TSO coordination. The service optimizesnetwork-capacity allocation, and makes room for additional integration of renewable-basedgeneration.

  • Ariza Rocha, Oscar David
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering.
    Dynamic transformers rating for expansion of expansion of existing wind farms2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Distribution system operators face the challenge to connect users rapidly to the grid and the opportunity to reduce costs for new connections. A method to enhance network operation and planning is dynamic transformer rating (DTR), which considers load and temperature variations to increase the rating of the transformer while maintaining in safe operation.

    This project investigates DTR application to an existing population of transformers connected to a wind park and proposes a method for adding new turbines to the grid using installed transformers. Five transformer locations and nine units belonging to E.ON AB are used to find the potential of DTR for network expansion.

    A weather analysis reveals that simultaneous high wind speeds and high temperatures seldom occur. An aging estimation based on the IEC 60076-7 standard shows that the transformers for wind power applications are underused. Considering the transformer thermal model, a sensitivity analysis shows that the parameters that mostly affect the aging rate are the moisture content, the hot spot factor, and the top-oil temperature rise. The maximum load to assure aging below 50 years is calculated for each transformer for different maximum hot-spot temperature levels showing that increasing the maximum allowed temperature reduces curtailment and increases aging. A single node analysis depicts the optimal expansion of wind power from a generator perspective, and a network analysis introduces further restrictions to the network. As a result, the optimal increase factor is around 30 to 50 % and is larger for higher hot-spot temperature limits.

    Accurate weather measurements and transformer parameters are necessary to make a proper estimation of transformer aging to unlock transformer potential. To use fiber optic temperature sensors in new transformers and on-site temperature measurements can increase the rating of the transformer. A maximum allowed temperature of 110◦C is conservative and limits the potential of the transformer for wind power applications. Finally, society benefits from DTR in wind power applications because there is a more efficient use of resources and additional renewable energy can be introduced to the network.

  • Ryan, Christian
    KTH, School of Electrical Engineering and Computer Science (EECS).
    On Optimization of Sequential Decision-Making in Customer Relationship Management using Deep Reinforcement Learning2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Customer relationship management (CRM) is a fickle but pivotal elementto the success of any business. Used correctly, it can not only yield higherrevenue and lower operational costs, but significantly boost customersatisfaction. Nonetheless, it can also be mismanaged—sacrificing thewell-being of customers for profitability. Industries have thereby beenflooded with a range of different heuristic strategies that aim to optimizeCRM. This thesis aims to instead study and optimize CRM using a datadrivenapproach, and present a framework that can readily incorporatecustomer well-being into the optimization process. More specifically: cana strategy that outperforms a business’ current strategy without any realworldimplications be derived using modern advances in reinforcementlearning? In this context, the lifetime value (LTV), i.e. net profit, of acustomer will be used as the objective function to optimize for.Using deep feed-forward neural networks, an artificial environmentmimicking typical customer behavior was attained. The model’s predictivecapabilities deviated merely a couple of percent from the true averagecustomer behavior seen in the data. This was further leveraged byan algorithm to obtain a business strategy through reinforcement learning.This novel algorithm is based on deep Q-networks, with furtherdomain-specific additions such as combined experience replay and doublelearning. The algorithmically derived business strategy theoreticallyoutperformed the current state-of-the-art business strategy by approximately100 percent in average 2-year LTV, and further outperformed aplethora of different business strategies.

  • Micski, Erik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    CO2 Flow Estimation using Sidestream Capnography and Patient Flow in Anaesthesia Delivery Systems2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Volumetric CO2 data from patients in anaesthesia delivery systems are sought after by physicians. The CO2 data obtained with the commonly used sidestream sampling technique are not considered adequate for volumetric CO2 estimation due to distortion and desynchrony with patient flow. The purpose of this thesis was to explore the possibility of using signal enhancing methods to the sidestream data to accurately estimate CO2 flow using a Flow-i anaesthesia delivery system.

    To evaluate sidestream performance, experimental data was acquired using a mainstream and a sidestream capnograph connected in series to a FRC test lung with known CO2 content, ventilated by a Flow-i anaesthesia machine. The data was then enhanced and analysed using signal processing methods including sigmoid modelling and neural networks.

    A Feed Forward Neural Network achieved results closest resembling the mainstream capnogram of the evaluated signal processing methods. The mainstream capnogram, considered the benchmark, produced large internal scattering and approximately 25 % offset from actual CO2 flow while using the inherent patient flow data produced by the Flow-i anaesthesia system. When using patient flow data from a Servo-i ventilator, the resulting CO2 flow estimates were drastically improved, producing estimates within 10 % error.

    This thesis concludes that there are several potential processing methods of the sidestream data to approximate the mainstream signal, however the patient flow of the Flow-i system are a suspected source of error in the CO2 flow estimation.

  • Man, Hengyu
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Efficient Intra Prediction for the Next-Generation Video Compression Standard2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    VVC (Versatile Video Coding) is a next-generation video compression standard.It is a potential successor to the MPEG-4/H.264 and High EfficiencyVideo Coding (HEVC)/H.265. Its first working draft was released in April2018 by MPEG and VCEG joint video exploration team. Its final standard isto be approved before the end of 2020. Video compression enables more efficientuse of transmission and storage raw video data to meet the increase ofdemand for high quality video over the internet.The objective of this thesis work is to research and implement algorithmsdeveloped at Ericsson Research to improve video coding efficiency. The algorithmis about intra angular prediction. The intra angular prediction usesprevious decoded samples of the current picture to predict the current block.In HEVC there are 35 directional intra prediction modes designed to be ableto efficiently model different directional structures typically present in videoand image contents. In VVC, the total number of directional intra predictionmodes increases to 67. This thesis work is to research a dynamic granularityintra angular prediction algorithm. The thesis work has investigated severalvariants of dynamic granularity intra angular prediction and focused on improvingvideo coding efficiency.

  • Ter Vehn, Anton
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Longitudinal Control Design for Autonomous HDVs2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Autonomous vehicles are evolving from a futuristic dream to current realityas technology becomes more and more mature. However, their presence on thehighways will demands precise control over lateral and longitudinal positioning.This thesis, completed at Scania Group AB in Södertälje, mainly focuses on thedesign of longitudinal controllers for trajectory tracking without compromisingalready mature control solutions. To this end, a virtual vehicle is created toextrapolate where the vehicle is supposed to be in time, and its position andvelocity are used as reference inputs. Then, two different control strategies (aPD controller and a lead compensator) based on position error and velocityerror are developed. A breaking algorithm is also developed to use servicebrakes on an Heavy-duty vehicle effectively. Numerical studies highlight thatthe proposed controllers exhibit excellent performance while tracking both positionand velocity trajectories. The proposed controllers are examined in threedifferent test cases: varying velocity, executing lane changes, and driving in anenvironment with significant changes in topology. In all test cases, the positionerror is less than 1m, while the velocity error is less than 0.5m/s. Comparedto the existing controller, developed in Scania Group AB, these controllers improvethe tracking performance significantly. Also, both controllers improverobustness against lateral changes and exogenous forces.

  • Székely, Éva
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Henter, Gustav Eje
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Beskow, Jonas
    KTH, Superseded Departments (pre-2005), Speech, Music and Hearing.
    Gustafson, Joakim
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    How to train your fillers: uh and um in spontaneous speech synthesis2019Conference paper (Refereed)
  • Betz, Simon
    et al.
    Zarrieß, Sina
    Székely, Éva
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Wagner, Petra
    The greennn tree - lengthening position influences uncertainty perception2019Conference paper (Refereed)
    Abstract [en]

    Synthetic speech can be used to express uncertainty in dialogue systems by means of hesitation. If a phrase like “Next to the green tree” is uttered in a hesitant way, that is, containing lengthening, silences, and fillers, the listener can infer that the speaker is not certain about the concepts referred to. However, we do not know anything about the referential domain of the uncertainty; if only a particular word in this sentence would be uttered hesitantly, e.g. “the greee:n tree”, the listener could infer that the uncertainty refers to the color in the statement, but not to the object. In this study, we show that the domain of the uncertainty is controllable. We conducted an experiment in which color words in sentences like “search for the green tree” were lengthened in two different positions: word onsets or final consonants, and participants were asked to rate the uncertainty regarding color and object. The results show that initial lengthening is predominantly associated with uncertainty about the word itself, whereas final lengthening is primarily associated with the following object. These findings enable dialogue system developers to finely control the attitudinal display of uncertainty, adding nuances beyond the lexical content to message delivery.

  • Székely, Éva
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Henter, Gustav Eje
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Beskow, Jonas
    KTH, Superseded Departments (pre-2005), Speech, Music and Hearing.
    Gustafson, Joakim
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Off the cuff: Exploring extemporaneous speech delivery with TTS2019Conference paper (Refereed)
  • Székely, Éva
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Henter, Gustav Eje
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Beskow, Jonas
    KTH, Superseded Departments (pre-2005), Speech, Music and Hearing.
    Gustafson, Joakim
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Spontaneous conversational speech synthesis from found data2019Conference paper (Refereed)
  • Székely, Éva
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Wagner, Petra
    KTH.
    Gustafson, Joakim
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    THE WRYLIE-BOARD: MAPPING ACOUSTIC SPACE OF EXPRESSIVE FEEDBACK TO ATTITUDE MARKERS2018In: Proc. IEEE Spoken Language Technology conference, 2018Conference paper (Refereed)
  • Sadik, Bala
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Elias, Sanar
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Svenska byggföretags ställning till Agenda 2030: En analys av Sveriges tio största byggföretag kring hållbarhetsarbete och mål2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis deals with the sustainability programmes and goals of Sweden's 10 largest constructioncompanies as well as their position on Agenda 2030. The fact that the concept of sustainability canbe perceived and defined in different ways around the world has created a certain ambiguity aroundthe notion. The largest construction companies in Sweden present sustainability reports that accountfor successful sustainability projects as well as future planning. The work of construction companiesin achieving the goals of Agenda 2030 is much the same, with the difference of some companieshaving unique approaches to achieving them. Several of the selected construction companies in thisthesis also have a number of goals set up that extend beyond the scope of 2030, partly because of theSwedish government's climate legislation for creating a climate-neutral Sweden by 2045.In this study, four goals from Agenda 2030 have been selected for analysis within the frame of thechosen construction companies' sustainability reports. The reports have been analyzed in order todecipher the companies’ different positions in regard to the chosen goals. The theory of weak andstrong sustainability applied in an organization has been applied to the sustainability of eachconstruction company, which produced a clear pattern as a result. The degree of strength within thesustainability efforts depends on the individual company’s turnover. This was relatively clear sincethe sustainability reports of the companies with a higher turnover were more comprehensive,contained more clearly presented progress, all while the number of Agenda 2030-goals was greater.Herein must be noted that the Signal Theory contradicts, to some extent, the assumption that thestrength of a company's sustainability is dependent on turnover, since companies can increase theirvalue and popularity through voluntary accounting and emphasize and highlight the ‘finer’ parts ofthe business.Future studies can find this study helpful in carrying out research within the same field. Even morein-depth investigational reports can be done using this study as a foundation, which could possiblybrighten prospects for deep-digging sustainability research into any type of company, constructionor non-construction. Sustainable work is a relevant topic in the world right now, which is whyfurther studies of this character will be needed in order to achieve a better understanding of thesustainability concept and development of effective strategies to make the world even moresustainable.

  • Wisseng, Sara
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Ölund, Linnea
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Coworking och dess påverkan vid värdering av kommersiella fastigheter2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The increasingly digitized, global and ever-connected society has made an impact on industries andworkplaces. In the real estate industry, coworking has become an increasingly well-knownphenomenon and is taking over an increasing share of the total office space. Coworking as a businessmodel replaces traditional leasing contracts with memberships. Companies gain access to flexibleoffice solutions with the possibility of networking and services, including everything from printers andconference rooms to beer taps and social events. Coworking offers short memberships instead of long,fixed leases, which has had a great impact among large and small companies around the world.Previous studies conducted in the US indicate that coworking over a certain proportion of a property’srentable area leads to a higher cap rate. The purpose of the study is to identify this relationship and toinvestigate whether coworking has an impact on the valuation of commercial properties in practice inSweden, and if so, what kind of impact. In addition, the study aims to investigate what real estateappraisers need to take into account when valuing property that includes coworking. The study isbased on theory regarding valuation models, uncertainty and risk connected to valuation as well asmarket analysis. In order to answer the study's questions, real estate appraisers from five differentwell-established real estate advisory companies in the Stockholm CBD-area have been selected andinterviewed.The result of this study indicates that there is a similar relationship between the proportion ofcoworking in a property and the cap rate in Sweden. However, an exact connection cannot beconfirmed due to lack of properties consisting of 100% coworking on the Swedish market. Dependingon how the market for coworking will develop, real estate appraisers will increasingly have to takeinto account the risk that coworking over a certain proportion of a property entails when valuingcommercial properties.

  • Engblom, Anna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Isacsson, August
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Poverty reduction through land titling: A study about the economic effects of the Malawi national land policy2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Access to land is vital for providing our basic needs. According to earlier research, private landtitles are a prerequisite for secure land rights and are vital for enabling sustainable economicgrowth and poverty reduction. In Malawi, where a majority of the land is customary, newlaws have been enacted, but not yet implemented. The new laws allow registration ofcustomary land into private land, i.e. land titling. This bachelor thesis investigates the possibleeconomic effects of land titling in Malawi based on earlier research and on the views ofMalawian stakeholders. It was found that the World Bank states that land titling will lead toincreased investments and improved productivity; increased credits access with lowerinterest rate; increased liquidity on transaction markets; increased access to rental market;increased mobility; increased gender equality and decentralization of power. Even though thecultural practices in Malawi partly collide with the privatization of customary land, thestakeholders generally agree with the effects described by the World Bank. It is difficult topredict the effects of the new laws as it depends on various factors. However, land titling willsurely lead to increased tenure security, which inherently is valuable for the landowners.

  • Gustafsson, Markus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Wåhlin, Johannes
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Hållbar finansiering: Fastighetsbolagens utformning av gröna obligationer2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish market for green bonds has increased explosively in recent years. Therefore, it’s surprising that there’s no established definition of the word green or any regulatory framework. Consequently, investors investments are jeopardized with minimum to no guarantees of sustainability. For that reason, this study will aim to sort out the issues that exists in the green bond market by studying issued bonds and what the property companies are prepared to deliver in return for capital. The hope is that the study will be able to increase transparency in the market and create discussion material for a future regulatory framework. The research question is as follows; How do property companies design green bonds on the Swedish bond market? The study is based on theories, concepts and models associated with real estate economics, bonds, environmental certifications and CSR. By means of an inductive qualitative method, the environmental certifications stated in the bond prospectus from the bonds already issued on the Nasdaq OMX Stockholm Nordic list of sustainable bonds, have been compiled. The result shows that BREEAM Very Good, Miljöbyggnad Silver and LEED Gold are the three most common environmental certifications. However, there are large differences between green bonds issued by governmental property companies and private property companies, where governmental property companies tend to issue a small proportion of green bonds but with higher requirements of environmental certifications, while private real estate companies tend to issue a large proportion of green bonds but to lowers levels of environmental certifications. This indicates an inconsistent and non-transparent market that undermines the concept of green bonds. The conclusion is that a definite definition of what is meant by a green bonds are required.

  • Lindqvist, Richard
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Värdering av kommersiella fastigheter baserat på ortsanalys: Fastighetsägare bör ha ett geografiskt diversifierat bestånd2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Strong fundamental conditions in the capital market have contributed to rising prices for real estate in general and in the geographical areas where institutional and international investors invest in particular. The core of this thesis is to compare different geographical office markets from an investor perspective, with the purpose of mapping what type of geographic location properties provide the strongest risk-adjusted return over time. In particular, to map the markets' historical growth to be able to categorize them as primary or secondary markets for offices, but above all by evaluating current yields on each market. After explaining central concepts and essential parameters within the subject, the risk measurement volatility is addressed as a possible argument to explain why real estate in the so-called secondary markets should be considered to have a lower risk than what the market expresses in the form of current yields. With submitted arguments, two alternative models are presented to determine yields in different geographic markets. The thesis ends with a simplified application of the models on two large property portfolios of different character; Hufvudstaden, whose properties are exclusively located in primary locations, and Klövern, whose properties are spread over 12 Swedish cities but in strong locations. Data from IPD, Datscha, Nordanö and PwC were collected for the studies. Overall, collected data supported the thesis that rents from properties in primary locations are being hit hardest by global crises and are generally more volatile than in secondary locations. In the simplified application of presented models, it could also be stated that a diversified portfolio provides stronger risk-adjusted returns over time, which is also in line with portfolio theory and the fact that market risk is the same regardless of how many assets that are included in a portfolio. From this thesis it can also be argued that an optimal real estate portfolio should be overweight to properties in secondary locations based on current values.

  • Johansson, Måns
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Strömberg, Malin
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Coworking – När är det fördelaktigt?: En jämförelse mellan coworking och traditionella kontor2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During the past years the demand for flexible office spaces on the Swedish office market has increased, which has cleared a path for a new concept – coworking. The concept, which shares some similarities with office hotels, is based on the philosophy that capital goods and services should be shared amongst parties. Due to the concept’s recent development on the Swedish market, there is a lack of studies from the tenant’s perspective. Throughout this essay we have used a qualitative research approach, where seven semi structured interviews have been carried out in order to answer the main question: When is it beneficial for the tenant to choose coworking?When renting a traditional office space, the contracts are regulated by 12th chapter in Jordabalken. However, these rental agreements are often written over three years and includes a specific period of notice when the contract is terminated. Coworking is a concept which tries to find the golden path for companies that do not have the possibility to sign long contracts.The conclusion states that it can be more profitable for smaller expanding companies to choose coworking over traditional office space. This is primarily due to expanding company’s requirement of flexibility, following difficulties regarding their ability to predict future office needs. Furthermore, the concept can be more suitable for companies with a lot of consultants, because the time spent in the office is decreasing. For smaller companies, coworking can also be sustainable both economically and ecologically. However, some companies that are working under legal secrecy might not be suitable to sit in coworking areas. The study has generated questions regarding whether coworking-agreement should be classified as a rental agreement or a membership, which should be researched further.

  • Public defence: 2019-11-07 10:00 Kollegiesalen, Stockholm
    Stigsson, Martin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Structural Uncertainties of Rock Fractures and their Effect on Flow and Tracer Transport2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A clear understanding of solute flow and transport through the network of fractures in the rock mass is essential for accurate long-term safety assessments of geological storage of hazardous waste. In a discrete fracture network (DFN) model, flow and transport of solutes are described by chains of flow paths through single fractures, each of which contributes to the total flow and transport properties of the rock mass. Hence, knowledge of the flow and transport properties of each single fracture is essential for accurate safety assessment.The void space that forms a fracture is a derivative of the roughness of the bounding surfaces and the normal force acting on the fracture and is hence dependent on accurate measurement of these properties. As all measurements are associated with uncertainties stemming from e.g. instrument imprecision, external disturbances and human factors, the measured value of the properties will not be single values, but probability distributions. Depending on the set of values drawn from these distributions, interpretations of flow and transport properties of sheared fractures in crystalline hard rock will vary.This thesis examines how flow and transport properties through single fractures are affected by uncertainties in fracture orientation and in roughness. By inferring the orientation and its uncertainty from the fracture intercepts in boreholes, a probability space for the orientation of the fracture is obtained. For a given stress state, this uncertainty in orientation will result in a distribution of normal stresses acting on the fracture. The roughness of the fracture and its uncertainty can be inferred from the small intersecting surfaces of the rock core, if the resolution is sufficient and the surface is representative of the fracture. The inferred roughness affects the correlation structure of the void between the two surfaces defining the fracture and, together with the distribution of normal stresses, produces different flow paths and hence different properties of flow and transport of solutes. Depending on the parameter combinations, the median and variance of the aperture field will change, as will the correlation structure of apertures. Since the flow and transport properties depend on the geometrical framework, the uncertainty will affect path length, travel time, transport resistance and flow-wetted surface. Higher normal stress acting on the fracture will typically result in longer travel times, longer travel lengths, higher transport resistance and larger flow-wetted surface. A rougher fracture will typically result in shorter travel times, longer travel lengths, lower transport resistance and smaller flow-wetted surface. The conclusion is, hence, that uncertainties in the geometric framework will affect flow and tracer transport properties.

  • Andersson, Gabriella
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Jonsson, Eva
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Transport Cartons' Impact on Supply Chain Efficiency2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Large product assortments commonly lead to that fast fashion retailers have a large number of transport cartons, with varying sizes, to distribute products from manufacturing sites to distribution centers. Ultimately, the transport cartons have a large impact on the supply chain efficiency, as they affect several nodes in the supply chain network. Previous research has considered transport cartons’ impact on individual supply chain nodes, but little research has been devoted to evaluate the transport cartons impact on the supply chain network as a whole. Thus, this thesis aims to contribute with knowledge to bridge the gap in literature by investigating how a company’s transport cartons affect the overall supply chain efficiency, by applying a holistic perspective.

    The thesis was conducted as a case study in collaboration with Hennes & Mauritz (H&M), aworld-leading fast fashion retailer. The research identifies opportunities and challenges related totransport carton usage, and how the cartons impact supply chain efficiency. Moreover, the research evaluates the costs associated with different sets of transport carton sizes, based on acost estimation model constructed on data provided by H&M. It is concluded that a small set oftransport carton sizes could increase supply chain efficiency and generate potential cost savingsdue to mainly two reasons. First, a small set of transport cartons could lead to efficient containerloading. Second, it could lead to efficient carton handling and optimal space utilization in thedistribution centers.

  • Frögren, Carolin
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Captivating Architecture2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The project concerns the subject of prisons. How should architects handle buildings that no one wants to enter and should comfort still be the aim of the building? These questions lead me to define my project with two main research questions: ”What is the purpose of a prison?” and ”How can the architecture aid the purpose of a prison?” Prisons are generally known to have four major purposes: Retribution, Prevention, Deterrance and Rehabilitation. Generally, rehabilitation have been prioritized the least. My focus was how the architecture can aid the purpose of rehabilitation, while still considering the balance of control, security, freedom and liberties. Swedish prisons today have one of three different levels of security. If a prisoner needs to change to a different security-level, it means moving them to a different prison, which is a security risk, among other things. My prison instead consists of four different levels of security within the same prison, and they are all organized around a “central park of opportunities”. This strategy is based on the current prison system in Sweden and the notion of free will. These four levels are connected to the park in different ways to emphasize the gradual release back to society. The park offers different places of work, education and variations in the landscape. It gives the inmates the opportunity to change their own circumstances for the better.

  • Madosh, Farzana
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Ålander, Betty
    KTH, School of Industrial Engineering and Management (ITM).
    An Evaluation of the Marketing Process in B2B and B2C Startups2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Marketing is a key function for all organizations and is seen as essential in order to achieve success when launching a new business. Following from the overwhelming amount of accessible data for companies, there exist an urge to understand what activities to include in the marketing process and how to manage them. Despite the vital role and the urge to further understand marketing, there is a lack of research about marketing in the small entrepreneurial business context that is encountered in startups. In addition, a call for further development of empirical research is identified in the business to business (B2B) and business to consumer (B2C) dichotomy. Therefore, the purpose of this study was to evaluate the marketing process used by B2B and B2C Software as a Service (SaaS) startups. This in order to contribute with understanding of the marketing process in the startup context and contribute with development of the research within the B2B and B2C dichotomy. This was done by conducting a multiple case study where the empire was collected from four SaaS startups either selling to consumers or businesses.

    The empirical findings of the study show that the customer type, being a consumer or a business, affects the marketing process. Both differences and similarities were identified between the marketing process applied in the B2B and the B2C startups. Due to different levels of knowledge within the companies and different complexity levels in the buying process differences were found in the evaluation, segmentation, targeting and positioning done by the B2B and the B2C startups. It was found that the B2B companies put in less effort into the market analysis and segmentation compared to the B2C companies. Historically the channels utilized were identified to be different between the segments. However, a trend towards similar targeting channels was identified since the B2B segment is moving towards using more inbound marketing, which already is the main approach applied by the B2C segment. The B2B segment was, compared with the B2C segment, also identified to put more emphasize on achieving a position within the market that radiates credibility. Furthermore, the marketing process was found to be approached differently in startups than what was suggested in literature due to the lacking attention given to the scare resources and the innovative environment of a startup. A suggestion was therefore provided of how the marketing process better could be adapted to the startup context by including a feedback loop, making the marketing process more iterative.

  • Leon Perlasca, José Arturo
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Automated climate calculations and 3D value-based visualizations: An Integration of BIM and LCA2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish Government has set a goal to reach net zero emissions of greenhouse gases by 2045, which together with the commissioning to the Swedish Housing Agency to prepare requirements for a climate declaration that shall reduce the climate impact from buildings, has enforce the AEC industry to provide solutions that help reach these targets. The introduction of the integration of BIM technologies, together with the LCA methodology has been suggested as a key solution to solve this problem. To achieve the results for this study, two main objectives were stablished. The first objective was to develop a BIM model in SMC able to produce automated climate calculations. The second objective was to perform interviews with relevant actors about this tool. The integration of those objectives helped to answer the research questions of this study. This study provides a way of performing automated climate calculations for construction projects using classification of materials in SMC and calculations in Excel. It also has the ability to perform data visualization of the carbon footprints of the complements in the 3D models of the project using the GWP of the chosen materials. It can be said that it is a great tool to introduce to decision-makers an easy way to identify the hotspots of carbon emissions and choose more sustainable alternatives.

  • Engzell Waldén, Frithiof
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Chasing Swans2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The last few years have seen an increasingly infected public debate about the appearance of contemporary buildings. Regardless of where one personally stands, this ought to be cause for architects to examine their own understanding of aesthetics. This project is an exercise in articulating and examining questions of architectural form. The project is divided into three parts; Theory, Observation, and Design. The first aims to establish a broad overview of the theoretical discourse surrounding the subject of aesthetics in architecture, as well as formulate a position within it. The second part is an observation of aesthetic experiences in practice, in which three existing works of architecture are broken down into component formal properties, and the experiences these evoke are put into words. The final part is an exercise in articulating the reasoning behind aesthetic design decisions. A small self-imposed design task serves as the catalyst for a sequence of explicitly formulated and documented design choices, leading from inception to finished design. 

  • Public defence: 2019-11-05 12:00
    Jovanovic, Nenad
    KTH, School of Electrical Engineering and Computer Science (EECS). Research Technology Institute, Comillas Pontifical University, Spain; Delft University of Technology, the Netherlands..
    Electricity markets operation planning with risk-averse agents: stochastic decomposition and equilibium2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The growing penetration of renewable energy sources in electricity systems requires adapting operation models to face the inherent variability and uncertainty of wind or solar generation. In addition, the volatility of fuel prices (such as natural gas) or the uncertainty of the hydraulic natural inflows requires to take into account all these sources of uncertainty within the operation planning of the generation system. Thus, stochastic optimization techniques have been widely used in this context. From the point of view of the system operation, the introduction of wind and solar generation in the mix has forced conventional generators to be subject to more demanding schedules from the technical point of view, increasing for example the number of start-up and shutdown decisions during the week, or having to face more pronounced ramps. From the point of view of the market, all these technical issues are transferred to the market prices that are subject to greater volatility. This thesis focuses on the problem of risk management using the Conditional Value at Risk (CVaR) as a coherent risk measure. The thesis presents a novel iterative method that can be used by a market agent to optimize its operating decisions in the short term when the uncertainty is characterized by a set of random variable scenarios. The thesis analyses how it is possible to decompose the problem of risk management by means of Lagrangian Relaxation techniques and Benders decomposition, and shows that the proposed iterative algorithm (Iterative-CVaR) converges to the same solution as under the direct optimization setting. The algorithm is applied to two typical problems faced by agents: 1) optimization of the operation of a combined cycle power plant (CCGT) that has to cope with the volatility in the spot market price to build the supply curve for the futures market, and 2) strategic unit-commitment model. In a second part of the thesis the problem of market equilibrium is studied to model the interaction between several generating companies with mixed generation portfolios (thermal, hydraulic and renewable). The thesis analyses how the Nash equilibrium solution is modified at different risk-aversion level of the risk of the agents. In particular, the thesis studies how the management of hydroelectric reservoirs ismodified along the annual horizon when agents are risk-averse, and it is compared with the risk-neutral solution that coincides with a centralized planning when the objective is the minimization expected operational cost.

  • Kärrbrant, Robert
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Labriz, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Analys av simulation för implementationer i en automatiserad verkstad2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A workshop that produces gearboxes planned to remodel the workshop. There were several problems that indirectly affected the production. The fact that trains stood still without doing active work on the main road in the workshop was a major problem. Another problem was that there were too many trains in the workshop. The planned reconstruction was to reduce the number of trains in the workshop. With the remodel, those responsible for the workshop wanted to explore further possibilities on how the workshop could be changed. It was also interesting to see if the implementation of changes would give an increased production.

    The goals were to create a simulation tool to investigate how different solutions based on the rebuild could affect a train that loaded the material into assembly lines in the workshop. To be able to test different solutions, a simulation model needed to be developed and verified against the existing solution. Then the model was expanded to test new solutions.

    From the workshop there was data on the consumption of materials. For the train that would load up on materials, there were theoretical times for various work tasks. The consumption of materials behaved according to a random distribution that was normally distributed. The result was that only the consumption of materials could be verified as there was only data on how the consumption of materials took place. Remaining parts of the simulation used theoretically planned values. Of the solutions investigated, it was a solution with a new bus stop on a less busy road, where a train could wait, that showed a more desirable result than the others that were investigated.

  • Dydek, Marta
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    A redesign of a pedestrian passage in Skärholmen Centrum: - variation on modernism´s theory of functional color2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Original project of Skärholmen was composed of a system of public spaces, but this was `broken´  by the closure of the connection between the two squares in 1986. Street between shopping buildings became part of the shoping mall. The current situation is dominated by the activity of consumption, and Storholmsgatan is characterized by an atmosphere of anxiety and constant over-stimutation. The project aims to think through what form of ´restoration´ of this system of public spaces could take. How can we work with quite constrained, long, linear spaces as site for architecture? What is the role of rhythm in producing experience? A theme for design is to produce spacial hierarchy and make  a contemporary variation on modernism’s approach of the funcional color in design process.  

  • Chen, Yijian
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Modern Translation of GuanZhong Narrow Courtyard2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Guanzhong narrow courtyard is a traditional architecture form of family house in Guanzhong area in China. This project will be dedicated to my grandmother.  She used to live in such house for decades. Although she has moved to city long ago, she is still missing the life in such narrow courtyard house. Unfortunately the old house has been teared down just like most of them in Guanzhong area. So I would like to design a new house for her and explore a way to translate the traditional architecture form into a modern building.  

  • Carlsen, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Varanger Sauna2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The detailing of many important and essential aspects of a building are initially neglected and thought of as a last step before the completion of a project, starting with the large scale working down to the small scale. They’re usually treated secondary and the general scheme is prioritized. Superficial and assembled rather than detailed and how it’s assembled. This creates a dilemma when necessary elements of a building begin to be considered how to be built and are treated as a problem, when it should be considered as an opportunity. More often than not, the product of a detail is a solution to a problem that was created. Not meaning the problem could’ve been avoided, the problem still needed to be solved regardless, but it was solved out of necessity and not as an asset to the project. This project was not about working backward, starting with a detail and working outwards to create a whole, to assemble fragments without any real sense of bearing. I didn’t use the detailing of the project just for the sake if it, to solve a problem that perhaps didn’t need to be solved. Instead embrace the challenge of a given situation as a seed from which a design process can grow. By briefly zoom in on a specific situation I hoped to develop a common language of the building as a whole. To create something that belongs to the building and not considered as an addition.

  • Cai, Jialu
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Skanstullsbron Library2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    I describe library as a place where one can detach from everyday life and attach to things that happened hundreds of years ago, happen in the fantasy world, happen in the spiritual space. With this description I regard library as a spiritual space rather than a functional building. It also influences all the decisions though out the design, site selection, space formation and material choosing. All these things put together to sculpture a place which is detach from everyday life. The site that I choose is under skanstullsbron which has a mega structure however surrounded by water and woods. The strong contrast between human scale and huge structure is the drama part of the design. A small out door space is design in the viaduct structure which is the closest to the top of the viaduct carry up this contrast to max. The original structure is beautiful therefore I design to create a place that people can stay and expose the original structure as much as possible. In this case, in the arch part I do not place any wall, just insert two bridges and platform to make it accessible.

  • Bäck, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Värmeverket: - ett ungdomens kulturhus2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Temat för projektet är social hållbarhet, för vilken bostadssegregation har blivit en alltmer kritisk faktor, eftersom vi idag ser hur bostadsområden blir alltmer uppdelade. En uppdelning vilken inte bara är socialekonomisk, som tidigare, utan även etnokulturell. I synnerhet är den här utvecklingen  alvarlig för de unga som kommer ta med sig den in i sin framtid. Idag är det etnokulturella avståndet mellan olika bostadsområden och förorter större än någonsin tidigare. Generellt för hårt segregerade samhällen är att det är de svaga grupperna som blir mest lidande, och därmed den förlorande parten i samhället, vilket visar sig i den fragmentisering och radikalisering som sker i termer av missbruk, kriminalitet med gängbildning och allt grövre vapen och religiös extremism – allt ett tragiskt utryck för en stegrande hopplöshet och brist på framtidstro. Ett ungdomens kulturhus är tänkt att motverka denna negativa utveckling genom att låta barn och ungdomar från olika etnokulturella miljöer mötas och därmed kunna utbyta tankar och erfarenheter. Därför blir den geografiska platsen avgörande viktig. I projektet fanns redan initialt en ambition att placera kulturhuset intill en sorts gränslinje som skiljer etablerade medelklassområden från mer invandrartäta. Bredäng är ett exempel på en förort som ligger mellan medelklassområden så som Mälarhöjden, Segeltorp med flera på ena sidan om gränsen och Sätra, Skärholmen och längre ut mot allt mer invandrartäta förorter som Vårby, Vårbygård, Alby och så vidare på andra sidan om samma gräns. I Bredäng finns ett nedlagt värmeverk som ligger på en plats som vetter mot Mälarhöjden. Det kan vara en strategisk fördel för verksamheten om kulturhuset är placerat så nära medelklassområden som möjligt, för att lättare dra till sig individer från dessa områden .

  • Sörberg, Svante
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Tran Florén, Simon
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Assessing the impact of floating-point precision in plasma simulations: A study of precision reduction and precisionrefinement in iPIC3D2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis explores how the precision of floating-point numbers affects the high-performance, implicit particle-in-cell plasma simulation software iPIC3D. We investigate whether a version of iPIC3D, modified to use floatingpoint numbers in lower precision than the current 64 bit double-precision, could yield accurate simulations in comparison with the current version. Such a version of iPIC3D could open the door for significant performance improvements thanks to architectural elements in modern GPUs that typically offer greater floating-point performance the lower the precision. Two different versions of iPIC3D’s particle mover were created. In the first, all variables were changed from double-precision to single-precision. The second version used precision refinement techniques to combat precision loss while still using single-precision floating-point numbers for the variables. The same simulation was run on the unmodified version of iPIC3D and the two modified ones. The output of the two modified versions were compared to the output of the unmodified version to see how the modifications affected simulations.

    The results suggest that iPIC3D’s particle mover cannot be run entirely in single-precision if high accuracy is required, especially over long time scales. However, macroscopic features of the simulated system remain largely unaffected. This motivates the usefulness of a single-precision version of iPIC3D that could give acceptable accuracy when studying more general properties of a plasma. The simulation using precision refinement techniques showed promising accuracy, but further study is needed to see what performance improvements can be gained from it.

  • Engström, Isak
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Ihre, Alan
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Predicting house prices with machine learning methods2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this study, the machine learning algorithms k-Nearest-Neighbours regression (k-NN) and Random Forest (RF) regression were used to predict house prices from a set of features in the Ames housing data set. The algorithms were selected from an assessment of previous research and the intent was to compare their relative performance at this task.

    Software implementations for the experiment were selected from the scikit-learn Python library and executed to calculate the error between the actual and predicted sales price using four different metrics. Hyperparameters for the algorithms used were optimally selected and the cleaned data set was split using five-fold cross-validation to reduce the risk of bias. An optimal subset of hyperparameters for the two algorithms was selected through the grid search algorithm for the best prediction.

    The Random Forest was found to consistently perform better than the kNN algorithm in terms of smaller errors and be better suited as a prediction model for the house price problem.

    With a mean absolute error of about 9 % from the mean price in the best case, the practical usefulness of the prediction is rather limited to making basic valuations.

  • Gessle, Gabriel
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Åkesson, Simon
    KTH, School of Electrical Engineering and Computer Science (EECS).
    A comparative analysis of CNN and LSTM for music genre classification2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The music industry has seen a great influx of new channels to browse and distribute music. This does not come without drawbacks. As the data rapidly increases, manual curation becomes a much more difficult task. Audio files have a plethora of features that could be used to make parts of this process a lot easier. It is possible to extract these features, but the best way to handle these for different tasks is not always known. This thesis compares the two deep learning models, convolutional neural network (CNN) and long short-term memory (LSTM), for music genre classification when trained using mel-frequency cepstral coefficients (MFCCs) in hopes of making audio data as useful as possible for future usage. These models were tested on two different datasets, GTZAN and FMA, and the results show that the CNN had a 56.0% and 50.5% prediction accuracy, respectively. This outperformed the LSTM model that instead achieved a 42.0% and 33.5% prediction accuracy.

  • Engelhardt, Erik
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Jäger, Simon
    KTH, School of Electrical Engineering and Computer Science (EECS).
    An evaluation of image preprocessing for classification of Malaria parasitization using convolutional neural networks2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this study, the impact of multiple image preprocessing methods on Convolutional Neural Networks (CNN) was studied. Metrics such as accuracy, precision, recall and F1-score (Hossin et al. 2011) were evaluated. Specifically, this study is geared towards malaria classification using the data set made available by the U.S. National Library of Medicine (Malaria Datasets n.d.). This data set contains images of thin blood smears, where uninfected and parasitized blood cells have been segmented.

    In the study, 3 CNN models were proposed for the parasitization classification task. Each model was trained on the original data set and 4 preprocessed data sets. The preprocessing methods used to create the 4 data sets were grayscale, normalization, histogram equalization and contrast limited adaptive histogram equalization (CLAHE).

    The impact of CLAHE preprocessing yielded a 1.46% (model 1) and 0.61% (model 2) improvement over the original data set, in terms of F1-score. One model (model 3) provided inconclusive results. The results show that CNN’s can be used for parasitization classification, but the impact of preprocessing is limited.

  • Bodelsson, Andrea
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Kollektiv odling i kris: - en antropocen trädgård2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    ”Collective cultivation in crisis – an Anthropocene garden” shows a vision of how the spaces in a Swedish city have been reshaped and restructured, perhaps as a consequence of societal decisions, perhaps through local initiatives – perhaps both.   The background to this project is obviously climate change, which most likely, in a few years’ time, will also affect food supply. It will then be necessary to grow locally, in Sweden and in our cities where most people live.   The idea is thus that the cultivated land and greenhouses will generate vegetables and legumes, which we today import and which will make up most of our food intake in the future. Transportation will be minimised, and the food will be consumed firstly by the city dwellers living around the cultivation, at the same time as the waste produced will generate heat and soil for the greenhouse and cultivation.   Around each garden, there is a wall made of earth that protects the cultivation from noise and exhaust from the motorway and also from the wind. The wall becomes a significant figure in the cityscape that frames and protects the cultivation. All the gardens have a central axis where the water is conducted and next to it there are the cultivations, framed by the walls which heat up the soil. The structure is strengthened by rows of greenhouses along the earth walls. The Anthropocene garden is neither a utopia nor a dystopia. The project is simply about how the future may necessarily come to look like, and about how the city can plan to meet future needs.

  • Holmgren Faghihi, Josef
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Gorgis, Paul
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Time efficiency and mistake rates for online learning algorithms: A comparison between Online Gradient Descent and Second Order Perceptron algorithm and their performance on two different data sets2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This dissertation investigates the differences between two different online learning algorithms: Online Gradient Descent (OGD) and Second-Order Perceptron (SOP) algorithm, and how well they perform on different data sets in terms of mistake rate, time cost and number of updates. By studying different online learning algorithms and how they perform in different environments will help understand and develop new strategies to handle further online learning tasks. The study includes two different data sets, Pima Indians Diabetes and Mushroom, together with the LIBOL library for testing. The results in this dissertation show that Online Gradient Descent performs overall better concerning the tested data sets. In the first data set, Online Gradient Descent recorded a notably lower mistake rate. For the second data set, although it recorded a slightly higher mistake rate, the algorithm was remarkably more time efficient compared to Second-Order Perceptron. Future work would include a wider range of testing with more, and different, data sets as well as other relative algorithms. This will lead to better result and higher credibility.

  • Bergström, Mattias
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Fahlander, Per
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Evaluating a Novel, Scalable Natural Language Processing Heuristic for Determining Semantic Relatedness2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     Distributional semantics is a recent research field aiming to quantify how close one text is to another in terms of contextual meaning. In this study we propose and evaluate a novel distributional semantics model on how much agreement its predictions can yield with a set of 12,227 human opinions. We call this method Refined Semantic Relatedness (RSR), which applies an incrementally improvable word association index and some distributional principles for producing theoretically educated predictions. Using 1951 preprocessed Wikipedia articles as a basis for the predictions, the model predicted the human opinions with a Pearson correlation of 0.3. In previous literature it has been claimed that Explicit Semantic Analysis (ESA-Wiki) achieve a corresponding Pearson correlation of 0.72 by utilizing 241,393 preprocessed Wikipedia articles. That is roughly 5.76 times more variance accounted for, although, also a result of considerably more extensive preprocessing in terms of articles. While the predictive value of RSR turned out relatively low as a result of the study’s limitations, this could be addressed in further research. We believe that this paper in any way can contribute with some novel ideas to the field.

  • Bernerstedt, Ingrid
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Varvet: A concert venue on Södermalm2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project proposes a new building for a concert venue on Södermalm in Stockholm. An area especially affected by the current trend that venues for experiencing contemporary music live are being shut down and driven away from the inner city, due to everything from complaining neighbours to making room for more profitable businesses. The idea for the project sprung out of the sudden closing of the venue Debaser Medis, whose facilities was removed when the building it was situated in was to undergo major renovations. The purpose with Varvet was to create a new venue in a freestanding building, independent from other businesses, and giving contemporary music a more articulated place in the city. The project also includes the re-purposing of an adjacent existing building to facilitate a cafe and bar as well as functions supporting the daily business of the venue such as offices, practice rooms and a small workshop. 

  • Taherifard, Ershad
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Load and Demand Forecasting in Iraqi Kurdistan using Time series modelling2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis examines the concept of time series forecasting. More specifically, it predicts the load and power demand in Sulaymaniyah, Iraqi Kurdistan, who are today experiencing frequent power shortages. This study applies a commonly used time series model, the autoregressive integrated moving average model, which is compared to the naïve method. Several key model properties are inspected to evaluate model accuracy. The model is then used to forecast the load and the demand on a daily, weekly and monthly basis. The forecasts are evaluated by examining the residual metrics. Furthermore, the quantitative results and the answers collected from interviews are used as a basis to investigate the conditions of capacity planning in order to determine a suitable strategy to minimize the unserved power demand. The findings indicate an unsustainable over consumption of power in the region due to low tariffs and subsidized energy. A suggested solution is to manage power demand by implementing better strategies such as increasing tariffs and to use demand forecast to supply power accordingly. The monthly supply forecast in this study outperforms the baseline method but not the demand forecast. On weekly basis, both the load and the demand models underperform. The performance of the daily forecasts performs equally or worse than the baseline. Overall, the supply predictions are more precise than the demand predictions. However, there is room for improvement regarding the forecasts. For instance, better model selection and data preparation can result in more accurate forecasts.

  • Axelsson, Henrik
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Wass, Daniel
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Machine Learning for Activity Recognition of Dumpers2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The construction industry has lagged behind other industries in productivity growth rate. Earth-moving sites, and other practices where dumpers are used, are no exceptions. Such projects lack convenient and accurate solutions for utilization mapping and tracking of mass flows, which both currently and mainly rely on manual activity tracking. This study intends to provide insights of how autonomous systems for activity tracking of dumpers can contribute to the productivity at earthmoving sites. Autonomous systems available on the market are not implementable to dumper fleets of various manufacturers and model year, whereas this study examines the possibilities of using activity recognition by machine learning for a system based on smartphones mounted in the driver’s cabin. Three machine learning algorithms (naive Bayes, random forest and feed-forward backpropagation neural network) are trained and tested on data collected by smartphone sensors. Conclusions are that machine learning models, and particularly the neural network and random forest algorithms, trained on data from a standard smartphone, are able to estimate a dumper’s activities at a high degree of certainty. Finally, a market analysis is presented, identifying the innovation opportunity for a potential end-product as high.

  • Olson, Julius
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Södergren, Emma
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Long Term Memory in Conversational Robots2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study discusses an implementation of a long term memory in the robot Furhat. The idea was to find a way to prevent identical and very similar questions from being asked several times and to store the information of which questions have already been asked in a document database. The project encompasses tf-idf, as well as a small-scale test with Word2Vec, to find a vector representation of all questions from Furhat’s database and then clustering these questions with the k-means method. The tests resulted in high scores on all the evaluation metrics used, which is promising for implementation into the actual Furhat robot, as well as further research on similar implementations of long term memory functions in chatbots.

  • Bergström, Emelie
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Durowicz, Aleks
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Establishing requirements for a gamified digital math tool in a South African township primary school: A case study based on gamification and interaction design2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     This project is based on the desire to increase the understanding and knowledge of digital resource usage within the math education in South African townships. Digital education is considered to facilitate solutions for current shortcomings, yet knowledge and experience of the local circumstances are vital for successful implementation. Interviews, observations and analyses of existing games were used to define requirements regarding design and usability, which were implemented through prototypes and evaluated formatively. This study indicates that the requirements of an educational and stimulating digital tool are the most important and suggest consideration of feedback, gamification features, such as storytelling, as well as the balance of formal and informal settings. Furthermore, user characteristics heavily implies low complexity, few distractions and a logical structure. Requirements of appropriate level, in both language and content, also proved to be crucial. However, this demands further assessment before implementation. The developed tool was perceived as suitable and was accepted as a long-term solution to make better use of the current resources. Although the limited time and the difficulty to comprehend the users’ opinions bounded the conclusions, the established requirements are suggested to provide a solid foundation for further research.

  • Gonzalez Munoz, Mario
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Hedström, Philip
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Predicting Customer Behavior in E-commerce using Machine Learning2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    E-commerce has been a rapidly growing sector during the last years, and are predicted to continue to grow as fast during the next ones. This has opened up a lot of opportunities for companies trying to sell their products or services, but it is also forcing them to exploit these opportunities before their competitors in order to not fall behind. One interesting opportunity we have chosen to focus this thesis on is the ability to use customer data, that has not been available with physical stores, to identify customer behaviour patterns and develop a better understanding for the customers. Hopefully this makes it possible to predict customer behaviour. We specifically focused on distinguishing possible-buyers from buyers, with the intent of identifying key factors that affect whether the customer performs a purchase or not. We did this using Binary Logistic Regression, a supervised machine learning algorithm that is trained to classify an input observation. We managed to create a model that predicted whether or not a customer was a possible-buyer or buyer with an accuracy of 88%.

  • Kästel, Arne Morten
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Vestergaard, Christian
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Comparing performance of K-Means and DBSCAN on customer support queries2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In customer support, there are often a lot of repeat questions, and questions that does not need novel answers. In a quest to increase the productivity in the question answering task within any business, there is an apparent room for automatic answering to take on some of the workload of customer support functions. We look at clustering corpora of older queries and texts as a method for identifying groups of semantically similar questions and texts that would allow a system to identify new queries that fit a specific cluster to receive a connected, automatic response. The approach compares the performance of K-means and density-based clustering algorithms on three different corpora using document embeddings encoded with BERT. We also discuss the digital transformation process, why companies are unsuccessful in their implementation as well as the possible room for a new more iterative model.

  • Mekonnen, Michael
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Tahir, Gara
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Vilka kriterier är viktiga för användarupplevelsen vid interaktion med en språkcafé-robot?2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As the number of immigrants in Sweden rises, the demand for alternative methods for language learning increases simultaneously. The use of social robots for teaching a second language is a promising field. The following research question has been designed to identify how social robots can be improved to better suit second language learners. The research question is: Which criteria are important for the user experience when interacting with a language cafe robot? The main method used to answer the question is Design Thinking with the help of semi-structured interviews. The results were 12 criteria which can be implemented for social robots in the future. The research has also studied how the criteria can be implemented in robots and to what degree the robot Furhat developed by Furhat robotics has implemented the criteria today.

  • Duque, Fredd
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Six DOF tracking system based on smartphones internal sensors for standalone mobile VR2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays mid-range smartphones have enough computational power to run simultaneous location and mapping (SLAM) algorithms that, together with their onboard inertial sensors makes them capable of position and rotation tracking. Based on this, Google and Apple have released their own respective software development kits (SDKs) that allow smartphones to run augmented reality applications using six degrees of freedom tracking. However, this same approach could be implemented to virtual reality head-mounted-display (HMD) based on smartphones, but current virtual reality SDKs only offer rotational tracking. In this study the positional tracking technology used for augmented reality mobile applications has been implemented in a virtual reality head-mounted-display only powered by a smartphone by combining virtual and augmented reality SDKs. Compatibility issues between SDKs have been faced to develop a working prototype. An objective and controlled measurement study has been conducted that included 34.200 measurements, to test the accuracy, precision and jitter tracking of the protype against the Oculus Rift, a dedicated virtual reality system. Results show that the developed prototype offers a decent tracking precision and accuracy in optimal conditions. It was concluded to be highly dependent on the camera view. Although, jitter presented the opposite behavior, being dependent to the device used but independent on the camera view. In its optimal conditions, user studies demonstrated that the prototype was capable of offering the same tracking performance feeling as the Oculus Rift although jitter was quite noticeable, and a common user complain. Further studies are proposed that can improve the tracking performance of the prototype by filtering jitter and using two or more cameras with a different angular to correlate feature points and obtain a wider view of the environment were the prototype is used.