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  • Public defence: 2019-09-13 13:00 Sal B, Kista
    Sollami Delekta, Szymon
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics.
    Inkjet Printing of Graphene-based Microsupercapacitors for Miniaturized Energy Storage Applications2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Printing technologies are becoming increasingly popular because they enable the large-scale and low-cost production of functional devices with various designs, functions, mechanical properties and materials. Among these technologies, inkjet printing is promising thanks to its direct (mask-free) patterning, non-contact nature, low material waste, resolution down to 10 µm, and compatibility with a broad range of materials and substrates. As a result, inkjet printing has applications in several fields like wearables, opto-electronics, thin-film transistors, displays, photovoltaic devices, and in energy storage. It's in energy storage that the technique shows its full potential by allowing the production of miniaturized devices with a compact form factor, high power density and long cycle life, called microsupercapacitors (MSCs). To this end, graphene has a number of remarkable properties like high electrical conductivity, large surface area, elasticity and transparency, making it a top candidate as an electrode material for MSCs.

    Some key drawbacks limit the use of inkjet printing for the production of graphene-based MSCs. This thesis aims at improving its scalability by producing fully inkjet printed devices, and extending its applications through the integration of inkjet printing with other fabrication techniques.

    MSCs typically rely on the deposition by hand of gel electrolyte that is not printable or by submerging the whole structure into liquid electrolyte. Because of this, so far large-scale production of more than 10 interconnected devices has not been attempted. In this thesis, a printable gel electrolyte ink based on poly(4-styrene sulfonic acid) was developed, allowing the production of large arrays of more than 100 fully inkjet printed devices connected in series and parallel that can be reliably charged up to 12 V. Also, a second electrolyte ink based on nano-graphene oxide, a solid-state material with high ionic conductivity, was formulated to optimize the volumetric performance of these devices. The resulting MSCs were also fully inkjet printed and exhibited an overall device thickness of around 1 µm, yielding a power density of 80 mW cm-3.

    Next, the use of inkjet printing of graphene was explored for the fabrication of transparent MSCs. This application is typically hindered by the so-called coffee-ring effect, which creates dark deposits on the edges of the drying patterns and depletes material from the inside area. In light of this issue, inkjet printing was combined with etching to remove the dark deposits thus leaving uniform and thin films of graphene with vertical sidewalls. The resulting devices showed a transmittance of up to 90%.

    Finally, the issue of the substrate compatibility of inkjet printed graphene was addressed. Although inkjet printing is considered to have broad substrate versatility, it is unreliable on hydrophilic or porous substrates and most inks (including graphene inks) require thermal annealing that damages substrates that are not resistant to heat. Accordingly, a technique based on inkjet printing and wet transfer was developed to reliably deposit graphene-based MSCs on a number of substrates, including flat, 3D, porous, plastics and biological (plants and fruits) with adverse surfaces.

    The contributions of this thesis have the potential to boost the use of inkjet printed MSCs in applications requiring scalability and resolution (e.g. on-chip integration) as well as applications requiring conformability and versatility (e.g. wearable electronics).

  • Bouju, Cecile
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Igergård, Fanny
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Wasted Potential: Potential of a food waste prevention model for the São Paulo street markets - A minor field study2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the municipal kitchens of Gothenburg, the implementation of the Gothenburg Model for reduced food waste has resulted in reducing the food waste by half in two years. The objective of this study is to contribute in the work of food waste prevention at the street markets in São Paulo by investigating how a model like the Gothenburg Model could be created and implemented. The study has mainly been carried out through a field study on a selection of street markets in São Paulo by performing observations, interviews and estimations of the food waste quantities. The findings of the study are that a model alike the Gothenburg Model could be of relevance at the street markets. It was found that both the model as a tool and as a process could be of use, with the phase of motivating and training the workers having special importance. The social responsibility felt by the vendors has been identified as a great opportunity to present not only donation but also food waste prevention as a social issue. The heterogeneity between the different market stalls and the lack of management on each market presents a challenge in the development and implementation of a tool. Further work should therefore be done to find solutions applicable to the various vendors and to investigate the eventual existence of natural leaders.

  • Public defence: 2019-09-12 13:00 F3, Stockholm
    Bütepage, Judith
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, Perception and Learning, RPL.
    Generative models for action generation and action understanding2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The question of how to build intelligent machines raises the question of how to rep-resent the world to enable intelligent behavior. In nature, this representation relies onthe interplay between an organism’s sensory input and motor input. Action-perceptionloops allow many complex behaviors to arise naturally. In this work, we take these sen-sorimotor contingencies as an inspiration to build robot systems that can autonomouslyinteract with their environment and with humans. The goal is to pave the way for robotsystems that can learn motor control in an unsupervised fashion and relate their ownsensorimotor experience to observed human actions. By combining action generationand action understanding we hope to facilitate smooth and intuitive interaction betweenrobots and humans in shared work spaces.To model robot sensorimotor contingencies and human behavior we employ gen-erative models. Since generative models represent a joint distribution over relevantvariables, they are flexible enough to cover the range of tasks that we are tacklinghere. Generative models can represent variables that originate from multiple modali-ties, model temporal dynamics, incorporate latent variables and represent uncertaintyover any variable - all of which are features required to model sensorimotor contin-gencies. By using generative models, we can predict the temporal development of thevariables in the future, which is important for intelligent action selection.We present two lines of work. Firstly, we will focus on unsupervised learning ofmotor control with help of sensorimotor contingencies. Based on Gaussian Processforward models we demonstrate how the robot can execute goal-directed actions withthe help of planning techniques or reinforcement learning. Secondly, we present anumber of approaches to model human activity, ranging from pure unsupervised mo-tion prediction to including semantic action and affordance labels. Here we employdeep generative models, namely Variational Autoencoders, to model the 3D skeletalpose of humans over time and, if required, include semantic information. These twolines of work are then combined to implement physical human-robot interaction tasks.Our experiments focus on real-time applications, both when it comes to robot ex-periments and human activity modeling. Since many real-world scenarios do not haveaccess to high-end sensors, we require our models to cope with uncertainty. Additionalrequirements are data-efficient learning, because of the wear and tear of the robot andhuman involvement, online employability and operation under safety and complianceconstraints. We demonstrate how generative models of sensorimotor contingencies canhandle these requirements in our experiments satisfyingly.

  • Wernius, Emma
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Olausson, Hanna
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Sekkenes, Martina
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Optimization of a solar water pumping system in Progreso, Amazonas, Colombia: Minor field study2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the villages along the Amazon river, the access to clean drinking water is lacking. In Progreso, the Swedish foundation Ankarstiftelsen and the non-governmental organization Entropika have installed a water purification system to solve this problem. The water used in the purification system is today pumped from a tributary to the Amazon river with a gasoline pump. This comes with social, ecologic and economic problems. To solve these problems, a solar water pumping system has been developed. After a preparing literature study on the topic, a field study was done to find relevant data. From this, an Excel program was made to optimize a suitable solution. Together with suggestions from three companies, two with a surface pump and one with a submersible pump, the system including a submersible pump was considered the most preferable. This mainly due to lower cost, weight and maintenance. Further, the suggestions were used to control the accuracy of the developed Excel program. This program can be used for future optimizations of systems with similar character.

  • Ebrahim, Mila
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Lilja, Fanny
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    The feasibility of producing and utilizing bioenergy in Linga Linga, Mozambique: Potential resources, conversion techniques and applications2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the project was to investigate the possibility of producing and utilizing bioenergy from available local resources in the village Linga Linga, Mozambique. Suitable conversion techniques for producing and utilizing bioenergy were identified through a literature study. The investigated techniques were the concept of gasifier cookstoves, the method of producing charcoal from biomass and anaerobic digesters. Through observations and interviews in the village, available local resources suited for the conversion techniques were identified. In the field study, it was found that there is a surplus of solid biomass which led to the conclusion that a gasifier cookstove is suitable to implement. In order to analyze if a gasifier cookstove is suitable for the households, interviews were carried out in ten households in the village. Aprototype of a gasifier cookstove was built with local resources to determine if the technique can be applied. The prototype was tested and evaluated in order to analyze if it will contributeto a more efficient use of resources. One of the conclusions of the study was that a gasifier cookstove can be valuable for the households in several ways, but that cultural differences can make it hard to implement.

  • Belaieff, Vera
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Barns mobilitet: En analys av barns skol- och fritidsresor samt det kommunala arbetet kring de respektive resorna2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Just like adults, children travel regularly in their everyday life. A major part of children’s travels goes to school, but apart from that children also do leisure travels to club activities and leisure facilities. The everyday travel habits of children affect both their health and independence. For this reason, this thesis will embrace children’s mobility and sustainable everyday travels. The aim is to raise the different travel types of children as well as present a basis for continued work within the topic.

    The study contains of literature research and questionnaires. One of the surveys was made in collaboration with Järfälla municipality. The two questionnaires, one for the students and one for their parents, investigated the travels habits to school and leisure activities for children in Skälbyskolan. Another questionnaire was sent to municipalities in the network of ResSmart. This survey collected information about if and how the municipalities work with children’s school travels and leisure travels, including also the reason why in some cases nothing was done.

    The result of the surveys showed that walking and cycling are the most common ways of transport to school. Most of the travels was done alone or with other children. Considering the use of bicycle, the use is dependent on the time of the year, where a large proportion cycle in summer but few in winter. To leisure activities, a great majority of the travels are made by car. Because of this, the independence of children’s leisure travel is generally non-existing. The reason why parents drive their children to leisure activities mainly depends on the distance, but also the time of the day in relation to darkness and the general family life. When driving children to school, the main reasons are lack of time and continued travels by car.

    When comparing Skälbyskolan with Gustav Vasa skola in the downtown of Stockholm, the result showed that walking is to most popular way of travel for both schools. However, neither cycling nor driving was made regularly to Gustav Vasa skola, even if the reasons when actually driving was the same as in Skälbyskolan.

    Regarding the municipality planning and actions, it is more common that municipalities work with sustainable school travels than children’s leisure travels. Furthermore, the working methods differ, where only physical arrangements are made within leisure travel routes and the lack of mobility management is a fact.

    With basis in the literature and survey results, action proposals are presented for a developed work within the area. For school travels, the actions should focus on reaching the parents and affecting their choice of mode, as well as actions for easier and more comfortable cycling during winter season. Considering leisure travels is the proposal to copy actions from the work with school travels, where the work should start off with inventions and travel habits surveys in leisure clubs. Furthermore, mobility management actions should be introduced, but also complex and long-term actions including leisure buses for children as well as compact city planning.

    Finally, the study mean that further work and surveys are needed for continued and developed work with children’s mobility. The area of children’s leisure travels should be raised both in planning documents and information, but also is media and larger forums.

  • Rosenberg, Barbro
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Tenfält, Markus
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Energy Scheme Proposal for Small Sugar Mills for Maximum Power Generation and Bagasse Saving during Harvesting Season2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy systems have significant importance for social development, not least in developing countries. A well-developed energy system can contribute to economic, ecological as well as social sustainability. At the same time, the ambitions to globally reduce dependence on fossil-based fuels and the climate impacting emissions that accompany them increase. To achieve this, energy efficiency improvements and an increased share of renewable energy sources are required. Today, there are both great challenges and opportunities in developing energy systems in developing countries and at the same time reducing the global climate impact.

    Thanks to the sugar industry in Cuba, there are great opportunities for the country to develop its electricity production from biofuels in the form of bagasse, a residual product which is provided during the process of the production of sugar. This report examines the possibility of developing the energy system in the sugar factory Carlos Baliño, located in Villa Clara in Cuba. The purpose is to enable the factory to minimize its use of bagasse and to maximize electricity production. This is to provide the opportunity for the factory to become more economical and ecologically sustainable.

    The current energy system in the sugar industry was examined and a model of the energy flows was created in excel. Based on the current energy system, four different scenarios were then examined with potential improvements. These four scenarios were as follows; (1) Preheating, (2) Bagasse drying, (3) Increase inlet boiler pressure and (4) New generator. For the various scenarios, the energy flow schemes were defined and technical components were selected. An economic and ecological analysis based on the best possible parameters of the scenarios was then performed.

    The result showed that the marginal electricity demand for the current system was 19 kWh per tonne of sugar cane and that the fixed electricity demand was 890 kW. The model defined the value of the bagasse as 8.2 USD per tonne, based on the current system. The current cut of costs by replacing oil were defined as 31 MUSD and the total amount of saved carbon dioxide was 96,000 tonnes, both for a period of 6 years. Out of the four scenarios that were investigated and compared with current systems, drying of bagasse was the option that could best be justified. This scenario resulted in a bagasse value of 5.0 USD per tonne, a cut of costs of 51 MUSD by replacing oil over a 6-year period and 150,000 tonnes of reduced carbon dioxide emissions over the same period.

    Preheating resulted in an increase in bagasse consumption, but also a higher electricity production. The result also showed that increasing the pressure in the boiler is not relevant, as the current pressure is almost the maximum for the current system. Due to a simplified model, Scenario 4, which included the investment of a new generator, could not be tested.

  • Public defence: 2019-09-06 10:00 F3, Stockholm
    Abdalmoaty, Mohamed
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control. KTH Royal Institute of Technology.
    Identification of Stochastic Nonlinear Dynamical Models Using Estimating Functions2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Data-driven modeling of stochastic nonlinear systems is recognized as a very challenging problem, even when reduced to a parameter estimation problem. A main difficulty is the intractability of the likelihood function, which renders favored estimation methods, such as the maximum likelihood method, analytically intractable. During the last decade, several numerical methods have been developed to approximately solve the maximum likelihood problem. A class of algorithms that attracted considerable attention is based on sequential Monte Carlo algorithms (also known as particle filters/smoothers) and particle Markov chain Monte Carlo algorithms. These algorithms were able to obtain impressive results on several challenging benchmark problems; however, their application is so far limited to cases where fundamental limitations, such as the sample impoverishment and path degeneracy problems, can be avoided.

    This thesis introduces relatively simple alternative parameter estimation methods that may be used for fairly general stochastic nonlinear dynamical models. They are based on one-step-ahead predictors that are linear in the observed outputs and do not require the computations of the likelihood function. Therefore, the resulting estimators are relatively easy to compute and may be highly competitive in this regard: they are in fact defined by analytically tractable objective functions in several relevant cases. In cases where the predictors are analytically intractable due to the complexity of the model, it is possible to resort to {plain} Monte Carlo approximations. Under certain assumptions on the data and some conditions on the model, the convergence and consistency of the estimators can be established. Several numerical simulation examples and a recent real-data benchmark problem demonstrate a good performance of the proposed method, in several cases that are considered challenging, with a considerable reduction in computational time in comparison with state-of-the-art sequential Monte Carlo implementations of the ML estimator.

    Moreover, we provide some insight into the asymptotic properties of the proposed methods. We show that the accuracy of the estimators depends on the model parameterization and the shape of the unknown distribution of the outputs (via the third and fourth moments). In particular, it is shown that when the model is non-Gaussian, a prediction error method based on the Gaussian assumption is not necessarily more accurate than one based on an optimally weighted parameter-independent quadratic norm. Therefore, it is generally not obvious which method should be used. This result comes in contrast to a current belief in some of the literature on the subject. 

    Furthermore, we introduce the estimating functions approach, which was mainly developed in the statistics literature, as a generalization of the maximum likelihood and prediction error methods. We show how it may be used to systematically define optimal estimators, within a predefined class, using only a partial specification of the probabilistic model. Unless the model is Gaussian, this leads to estimators that are asymptotically uniformly more accurate than linear prediction error methods when quadratic criteria are used. Convergence and consistency are established under standard regularity and identifiability assumptions akin to those of prediction error methods.

    Finally, we consider the problem of closed-loop identification when the system is stochastic and nonlinear. A couple of scenarios given by the assumptions on the disturbances, the measurement noise and the knowledge of the feedback mechanism are considered. They include a challenging case where the feedback mechanism is completely unknown to the user. Our methods can be regarded as generalizations of some classical closed-loop identification approaches for the linear time-invariant case. We provide an asymptotic analysis of the methods, and demonstrate their properties in a simulation example.

  • FERNANDEZ BARRERO, DIEGO
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Dynamic Soil-Structure Interactionof Soil-Steel Composite Bridges: A Frequency Domain Approach Using PML Elements and Model Updating2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis covers the dynamic soil structure interaction of soil-steel culverts applyinga methodology based on the frequency domain response. At the first stage of this masterthesis, field tests were performed on one bridge using controlled excitation. Then, themethodology followed uses previous research, the field tests, finite element models (FEM)and perfectly matched layer (PML) elements.Firstly, a 2D model of the analysed bridge, Hårestorp, was made to compare the frequencyresponse functions (FRF) with the ones obtained from the field tests. Simultaneously, a 3Dmodel of the bridge is created for the following purposes: compare it against the 2D modeland the field tests, and to implement a model updating procedure with the particle swarmalgorithm to calibrate the model parameters. Both models use PML elements, which areverified against previous solution from the literature. The verification concludes that thePML behave correctly except for extreme parameter values.In the course of this master thesis, relatively advanced computation techniques were requiredto ensure the computational feasibility of the problem with the resources available.To do that, a literature review of theoretical aspects of parallel computing was performed, aswell as the practical aspects in Comsol. Then, in collaboration with Comsol Support and thehelp given by PDC at KTH it was possible to reduce the computational time to a feasiblepoint of around two weeks for the model updating of the 3D model.The results are inconclusive, in terms of searching for a perfectly fitting model. Therefore,further research is required to adequately face the problem. Nevertheless, there are some accelerometerswhich show a considerable level of agreement. This thesis concludes to discardthe 2D models due to their incapability of facing the reality correctly, and establishes a modeloptimisation methodology using Comsol in connection with Matlab.

  • Gustafson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Hur urban täthet och rymlighet hanteras i Hagastaden2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Urban density is an ideal that characterizes today's urban planning in Sweden. This is evident from various general planning documents as well as the densification projects, e.g. Hagastaden in Stockholm, which are a result of these. This paper aims to find an understanding of how urban density and spaciousness are balanced in Hagastaden, and how Hagastaden resembles or differs from other development areas in this respect. Hagastaden and Norra Djurgårdsstaden, another densification project in Stockholm, are compared with respect to density, partly at an area level and partly at a block level. As for the area level, the floor space index (FSI) is calculated for an entire detailed development plan area. In Hagastaden’s plan area DP1 and in Norra Djurgårdsstaden plan area etapp Västra. As for the block level, the floor space index (Swedish: nettoexploateringstal), land use (Swedish: andel bebyggd mark) and spaciousness index (Swedish: rymlighetstal) are calculated, as defined by Rådberg et al (1996), for one block in each area. The block Cellen is chosen in Hagastaden and in Norra Djurgårdsstaden the block Töfsingdalen. These blocks are also compared with the main groups of Swedish city types as described by Rådberg et al. Hagastaden's public open spaces, i.e. park and square areas, are analyzed based on guidelines from the document Grönare Stockholm and the so called Alviksmodellen. The result of the density comparison shows that Hagastaden is considerably denser than both Norra Djurgårdsstaden and the main groups of Swedish city types. DP1 in Hagastaden has an area-wide floor space index of 2.54, compared to 1.65 for etapp Västra in Norra Djurgårdsstaden. Furthermore, the housing block Cellen in Hagastaden has a floor space index of 4.20, compared to 2.57 for Töfsingdalen in Norra Djurgårdsstaden. Both blocks exceed all main groups of Swedish city types with respect to floor space index, but most closely resemble the main group Big city blocks (Swedish: Storstadsmässiga kvarter). The difference in floor space index seems to be mainly due to the difference in number of floors, where the block Cellen has an average number of 11.1 floors and the block Töfsingdalen 7.1 floors. DP1 in Hagastaden, with a 16.7 % share of public open space, achieves the Alviksmodellen guideline of at least 15% public open space. However, it does not achieve the guideline of at least 10 m2 of public open space per resident with only 6 m2 per resident. Furthermore, the guidelines for good access to park and nature are only partly met.

  • Carlson, Douglas
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Out-of-Character: Current and Potential Use of 'Character' in the Development of Swedish Urban Areas2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Character is a term used in urban development and research to describe aspects of the built environment ranging from aesthetics and design to place identity and sense of place. This wide range of interpretations has led to a vague understanding that differs depending on the perception of users and actors in urban development. In the face of increasing housing demands and incentives to expand, Swedish urban environment has begun expansion that mirrors that of the Million Programme. To avoid a detached environment, character is investigated and proposed to be used as a tool for municipalities in the development. The focus is on answering what ‘character’ is perceived as by municipal officials involved in the urban development process, how character should be used and lastly how character should be approached when developing existing areas. Based on interviews for a practical understanding, literature for a theoretical understanding and contemporary studies for a contextual understanding, character is found to be perceived as the connection between not only existing buildings but also new ones as well as the users themselves. With emphasis on cohesion, originality, traditionality, diversity among other attributes, the character of an area should act as a binding agent for urban development moving forward. Finally, the approach to character is recommended to be cautious based on its vague nature but be treated as exploratory where a base set of two foundational attributes are to invite discussion to bridge the perceptions between actors.

  • Fröjd, Felicia
    KTH, School of Industrial Engineering and Management (ITM). KTH.
    Evaluation of quantification methods for inclusion distribution in clean steel2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Ovako products are in many cases used in high fatigue applications. Currently Ovako use ultrasonic evaluation at 10 MHz as a volumetric method for inclusion control. This study intends to investigate two new methods for quantification of micro inclusions.The aim of this study is to develop a method for large area scanning by creating a polishing method that allows you to polish away a specified amount of material, in this case 60 μm. This method will be used to capture the true distribution of critically sized non-metallic inclusions by creating a 3D image out of several 2D scans from the light optical microscope. These results will be compared to the results of high frequency ultrasonic testing at 125 MHz to get a quantitative idea of what can be captured by the high frequency ultrasonic investigation.Two different steel grades were studied, named Grade A and Grade B, with one sample of each. Both grades have similar composition, except that Grade B contains more sulphur. Both grades are of approximately the same hardness. The two steel samples were scanned with a scanning acoustic microscope at the same time as a method to polish away 60 μm was developed. After this, the method was used to scan several layers with an image recognition program in the light optical microscope. The results from both methods were then compared.After testing, it was concluded that the inclusion distribution pattern was completely different for the two steel grades, however the same pattern could be seen for each grade in the LOM and in the ultrasonic. This indicates that the same types of inclusions could be found. It was also found that the ultrasonic enlarges the indications by a severe amount making it hard to take any measurements directly from the ultrasonic images in this study. What is possible to see in the ultrasonic images are the distribution of inclusions and the inclusion placement in the sample. A result of 10 % matching inclusions between both methods is found, which is to say that the same 50 inclusions out of the 500 largest indications from each method in the steel sample is found. These 10 % is however not sufficient enough to conclude by how much the ultrasonic enlarges the indications compared to the light optical microscope.

  • Lundström, Linnéa
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability and Environmental Engineering.
    Managing freight transport as a city: Decreasing climate change impact and reaching sustainable mobility2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Climate change impose a major challenge to the world. About 23% of the world’s energy-related CO2 emissions derive from transportation. Urban freight transport has been increasing because of a growing demand for goods. Cities need to manage freight transportation to decrease its climate change impact. The purpose of this study is to investigate what the cities Gothenburg, Copenhagen, and Turku need in order to manage urban freight transport and what measures the cities have adapted to reduce the CO2 emissions deriving from urban freight transport. The study aims to reflect upon how the elements included in the practice of municipal freight transport management relate to the sustainable mobility paradigm and identify measures to decrease climate change impact and reach sustainable mobility.

    Social practice theory guided the analysis, where meanings, materials, and competences was searched for in the empirical material. Data was collected through a document analysis and interviews with employees at the cities’ administrations. The results showed that the reasons for managing freight is to reduce environmental and negative social impacts, ensure good ease of passage for freight transportation, strengthen the economy and create jobs, and avoid conflicting goals and find joint solutions. Needed materials are funding, guidelines, and personnel resources. Needed competences include taking a systems perspective, understanding the private sector, engaging in cooperation, seeking and managing funding, transport planning, and procurement and planning of the own municipal freight transportation. The need and behaviour that steers the freight transportation seem to be excluded from the freight transport management practice. This is the need for goods and its connected consumption behaviour. The cities’ adapted measures to reduce the climate change impact from freight transportation focus on technological and logistical improvements. The freight transport management practice includes features that are in line with the sustainable mobility paradigm as well as features that are not. To strengthen sustainable mobility, the inclusion of stakeholders when managing freight transport could be expanded to inhabitants and persons with competence in environmental and social aspects.

  • Blomqvist, Camilla
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Zingmark, Natalie
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Optimala biodrivmedel för inblandning i diesel: En jämförelse mellan tre biodrivmedel2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In 2018, the Swedish government decided to impose an obligation of reduction that aims to reduce greenhouse gas emissions in the transportation sector and thereby increase the use of biofuels in our society. Fuel suppliers in Sweden have through this obligation of reduction a responsibility to mix renewable fuels into fossil fuels. For diesel an equivalent of 20 percent of greenhouse gases must be reduced by mixing in biofuel until 2020 and from 2021 onwards, 21 percent greenhouse gases will be reduced each year. The goal of a fossil-free transportation sector in year 2030 is therefore expected to be achieved successively year by year through this initiative. The problem, however, is that there are not an enough amount of biodiesel today to be able to replace fossil diesel to the level required by the obligation. Therefore research, innovations and investments are required to enable the expansion of the biodiesel production so that the need for biofuels can be met. The purpose of this report is to investigate which biodiesel is the most optimal for mixing in to diesel based on supply, cost and environmental impact. The goal is a fossil-free and environmentally sustainable transport sector and to perform this investigation of which biodiesel performs the best, a literature study has been conductedon the fuels HVO (hydrogenated vegetable oil), FAME (fatty acid methyl ester) in the form of RME(rapeseed methyl ester) and FT-diesel (Fischer Tropsch diesel) in the form of BTL (biogas to liquid).Then, a multi-criteria analysis (MCA) followed by a sensitivity analysis has been implemented to compare the three alternatives against each other in a number of criteria selected by the authors of this report. The result showed that the fuel HVO generated the highest average value from the MCA, which is as sumed to be the most optimal. In the sensitivity analysis conducted to test the results uncertainties and sensitivity to hypothetical changes in the future, HVO and FT diesel performed best. RME performed poor in the multi-criterion analysis and the sensitivity analysis, which means that it is not suitable for use to a greater extent than it is today. The criticism that is directed at the tool MCA usually involves the result having a certain type of subjectivity such that the points awarded are influenced by the authors' knowledge and experiences. One of the reasons why sensitivity analysis is carried out is to try to eliminate this uncertainty that the subjectivity brings. The parameters that have the greatest impact on the result and which the authors consider to have the greatest impact on the future development are the availability of raw materials, the production cost and how much is produced by each fuel annually. The conclusion is that HVO is most optimal for mixing in in dieseltoday, but is faced with the challenge of finding alternative raw materials since decay products that HVO are produced from occur in a limited amount. BTL would be a strong candidate to being the most optimal for blending in if investments were made so that it would be available on the commercial market. RME has many short comings and is not suitable for expansion, a decision that the EU has already taken and which this report validate.

  • Lundquist, Frida
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Selsmark, Dan
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Vattenkraftsplanering i kombination med vindkraft och Vattenkraftsplanering i kombination med vindkraft och batterier2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Battery storage may be a key factor towards a CO2 free power system. However, a condition for this solution to befeasible is that it is still economically sustainable for the powerplant owners. The aim of this project is to examine how batterystorage affects a power system consisting of hydropower and windpower, and to draw conclusions about if battery storageis to recommend the power system. Furthermore, a suitable amount of installed battery capacity is to be found. The method includes designing a fictive model of a power system and solvingan optimization problem. The fictive power system model is based on existing hydropower plants in Luleälven in northern Sweden supplemented by windpower and batteries. It is modeledas a deterministic linear optimization problem (LP) and solved with the programming tool GAMS (General Algebraic ModellingSystem). To examine the effects of energy storage in the power system, four case studies are made with different amounts of battery capacity installed in the system. Because the optimization problems are all solveable and generate a profit, battery storage can be recommended to the fictive power system. Installing battery capacity increases the variations in the hydropower production,escalating with higher amounts of batteries. A moderate amount of batteries is found to be the most suitable amount with respect to profit and hydropower planning.

  • Isacson, Jonas
    KTH, School of Industrial Engineering and Management (ITM).
    Network Interconnectivity Prediction from SCADA System Data: A Case Study in the Wastewater Industry2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Increased strain on incumbent wastewater distribution networks originating from population increases as well as climate change calls for enhanced resource utilization. Accurately being able to predict network interconnectivity is vital within the wastewater industry to enable operational management strategies that optimizes the performance ofthe wastewater system. In this thesis, an evaluation of the network interconnectivity prediction performance of two machine learning models, the multilayer perceptron (MLP) and the support vector machine (SVM), utilizing supervisory control and dataacquisition (SCADA) system data for a wastewater system is presented. Results of the thesis imply that the MLP achieves the best predictions of the network interconnectivity. The thesis concludes that the MLP is the superior model and that the highest achievable network interconnectivity accuracy is 56% which is attained by the MLP model.

  • Eklind, Klara
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Myhr, Elina
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Glapp mellan vision och genomförande?: En undersökning av förutsättningarna för införandet av konceptet “smart stad” i Stockholm stad2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today, the world's societies and cities face new challenges in the face of heavy urbanization and major climate change, where the concept of "smart city" is seen as a solution. However, the “smart city” definition is still undecided, and many use the concept in different contexts, which can be confusing. This paper aims to broaden the understanding of what a "smart city" is and how it can be defined according to research and lastly studying the Stockholm city organization in their work to realize its vision "to become the world's smartest city 2040" with help using the framework institutional capacity. The study is conducted with a theory study of the concept "smart city" and a case study that deals with the City of Stockholm's strategic steering documents and interviews of people who work with the municipality's urban development in different ways. Institutional capacity is used in this thesis to study the ability to interpret knowledge resources, relational resources and mobilization capacity within the City of Stockholm work to create change in practice and finally the transformation of the city's qualities. The city's organization is analyzed to answer the questions: What do different actors in Stockholm city mean when they discuss "the smart city", what meaning do they put in the concept and also if there is a gap between the city's vision and the practical work? The study's conclusions are that Stockholm city has the skills and strategies to succeed, but the construction of the organization makes the work difficult. In order for the city to succeed with their transformation into the world's "smartest city they need to increase collaboration within the municipality and also a strong guiding leadership is required. New roles have been added and more need to be added in order to fill the missing skills. Stockholm City has worked on promoting innovation in recent years and new working methods focusing on the "smart city" with the help of innovation and digitization have been added. Stockholm city is in the start-up phase with their transformation and the question is if the ambition “smart” is theoretical trend or if the city is soon "smart" even in practice.

  • Johansson, Niklas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Karlsson, Saga
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Water reuse in peri-urban areas: A case study of Kibondemaji, Dar es Salaam,Tanzania2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An increasing number of countries worldwide is becoming water-stressed, sub-Saharan Africa being one of the most recurrent regions within this discourse. Tanzania, one of the countries in the region, is no exception: large population growth has increased pressure on its precious water resources. The largest city, Dar es Salaam, has a poorly maintained and dimensioned water supply and wastewater system. However, as this system expands and more people are given access to the water network, the water consumption of the city is expected to increase. This is problematic for the whole city; however, peri-urban areas suffer the most from its consequences, e.g. periodical water shortages. This report seeks to investigate the potential for saving water in one of these peri-urban areas, Kibondemaji, by looking at fields of application and techniques for reuse of wastewater from showers. This is done via a literature review and interviews in the field in order to analyse and compare the different systems – reuse for tap water, irrigation and toilet flushing. The interviews showed that there is wide acceptance within the community for water reuse for toilet flushing but not for tap water or irrigation. Reuse for toilet flushing also requires less treatment than other fields of application, thus being the most promising technique for implementation in Kibondemaji.

  • Lennartsson, Anna
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Inkluderande stadsutveckling: Förståelser och metoder inom kommunal planering2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Promoting equality and proper living conditions is gaining focus in city development contexts today. Swedish research shows differences in social conditions between different urban districts and that access to services, workplaces and social networks is often poor in districts where inhabitants have limited economic resources. Additionally, these districts are often surrounded by physical and social barriers and thus different social groups are divided. This situation is referred to as an important driver for polarisation and social instability. Meanwhile, some of these urban districts are experiencing strong growth as they are developed into centres for commercial and business life. This brings the question on how social inclusion can be promoted in city development up to date. The aim of this study is to contribute to the knowledge on how inclusive city development is understood in the context of municipal planning, and to map methods that can be used to create inclusion on the municipal level. The aim is also to contribute with a knowledge base to support the development of Flemingsberg in Huddinge municipality.

    The study is based on semi-structured interviews with municipal officers involved on different levels of the city development process, from strategic planners to managers of individual projects. The interviews have been analysed with a discursive approach to examine the understanding of inclusion. Also, good examples of concrete tools and ways of working with inclusion have been mapped from the interviews. The analysis shows that the discourse on inclusion in municipal planning is in fact consisting of several discourses, of which social mixing, cohesion and participation are the focus. Mixing is largely understood as the addition of socioeconomically strong residents in socioeconomically weak neighborhoods, which is believed to contribute to the social cohesion between different social groups. Furthermore, this cohesion is seen as an important factor for mitigating the effects of social problems and to create a feeling of safety and affinity. This is contrasted by a sort of fear and division that seems to be existing today. Citizen participation is described as important for creating and maintaining trust when socioeconomically weak neighborhoods are developed, and methods of participation are common among the good examples brought up by the interviewees. Other methods are connected to the organisation of city development projects, economic tools and initiatives run by citizens.

  • Granqvist, Jessica
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Gao, Lily
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    The electricity demand andsupply in El Espino: Alternatives for diversification of renewabletechnologies2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of alternative fuels, particularly renewable energy sources, has been an important strategy to achieve greenhouse gas emission reductions. In Bolivia, many rural areas struggle with an unreliable power supply. The most common electricity solution in such isolated areas is to have off-grid systems, where hybrid systems have become a feasible solution. In this study, a hybrid system in the rural village El Espino is optimized using a linear programming tool called MicroGridsPy. Currently, the village is powered by a hybrid system consisting of solar photovoltaics, a diesel generator and lead-acid batteries as a storing system. To optimize the system in a sustainable way, considering economic, environmental and social aspects, two wind turbines of the nominal capacities 5 and 10 kW are studied and introduced to the hybrid system. To find synergies between the wind and solar energy, the irradiance and wind speed of the study area are simulated using a Weather Research and Forecasting (WRF) model. The power output from the wind turbines can then be obtained by modelling the power curves and then be added to the optimization model. The optimization is performed both with and without the wind turbines to evaluate the impact of them. In the optimization model, characteristics of the components, techno-economic parameters, including investment costs, and constraints such as renewable penetration, and cost of the curtailment are set.

    The obtained results include that the wind speed is higher during the winter season, and that the wind power output, regardless of turbine size, is proportional to the wind speed. Furthermore, the 10 kW wind turbine is proven to be the most suitable for the system of the two compared. The economical values of the system, such as NPC and LCOE are higher, the higher the renewable penetration, but lower for the system with wind turbines. This implicates that adding wind energy to the hybrid system could be beneficial from both an environmental and economical point of view. One conclusion that can be drawn is that wind turbines are a feasible technology for rural electrification, and that the optimization tool is sensitive to cost. Furthermore, it is found that the wind and solar energy are suitable complements to each other both season wise and daily.

  • Chen, Yupei
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Classification of Atypical Femur Fracture with Deep Neural Networks2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Atypical Femur Fracture(AFF) is a type of stress fracture that occurs in conjunction with prolonged bisphosphonate treatment. In practice, AFF is very rarely identified from Normal Femur Fracture(NFF) correctly on the first diagnostic X-ray examination. This project aims at developing an algorithm based on deep neural networks to assist clinicians with the diagnosis of atypical femurfracture. Two diagnostic pipelines were constructed using the Convolutional Neural Network (CNN) as the core classifier. One is a fully automatic pipeline, where the X-rays image is directly input into the network with only standardized pre-processing steps. Another interactive pipeline requires the user to re-orient the femur bones above the fractures to a vertical position and move the fracture line to the image center, before the repositioned image is sent to the CNNs. Three most popular CNNs architectures, namely VGG19, InceptionV3 and ResNet50,were tested for classifying the images to either AFF or NFF. Transfer learning technique was used to pre-train these networks using images form ImageNet. The diagnosis accuracy was evaluated using 5-fold cross-validation. With the fully automatic diagnosis pipeline, we achieved diagnosis accuracy of 82.7%, 89.4%, 90.5%, with VGG19, InceptionV3 and ResNet50, respectively. With the interactive diagnostic pipeline, the diagnosis accuracy was improved to 92.2%, 93.4% and 94.4%, respectively. To further validate the results, class activation mapping is used for indicating the discriminative image regions that the neural networks learn to identify a certain class.

  • Laab, William
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Pataky, Adam
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Impact of Interest Rate Increase on Stockholm’s Households2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The housing prices have increased in a rapid pace in Stockholm the past decades. Simultaneously, the interest rates have decreased drastically, since the global financial crisis in 2008. The two movements combined have led to higher debt among Swedish households and especially in the capital, Stockholm. This article presents a quantitative research investigating which types of households, based on their social economic profile, will be mostly affected by an increased mortgage rate. The DSR is calculated for each HH, taking in account the amortization regulations introduced in 2016 and 2018. By doing a regression analysis using the DSR as the dependent variable and the socioeconomic factors as independent variables, we find that income and age are the variables with highest significance describing the DSR. Additionally, we investigate the socioeconomic profile of those households that have the highest DSR increment, based on specific cluster made by Insightone. The findings of the paper suggest that four out of 44 types of families have exceptionally higher exposure to the two different mortgage-rate increase scenarios. Three of these four family clusters are young, have children, high income and lives in houses. The remaining family cluster is young, have no children, has low income but is highly educated.

  • Li, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Developing a Bottom Up Cost Calculation Model and Methodology for Thermal Storage Applications2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Increasing storage for energy is one of the most important challenges today to overcome in order to enable higher penetration of renewable energy in the existing energy systems. Thermal storage is one category of energy storage that has been successfully demonstrated in a number of engineering projects and is showing promising potential in the future. However, a technology cannot be widespread if it is not economically feasible and sustainable in the long run. Bottom up cost analysis can be used to assess economic viability of a technology. For newer technologies, the top-down cost calculation is not always possible due to the limited amount of data. The aim of this thesis is to investigate the best practices in performing bottom up cost calculation and to propose a methodology with the purpose of enabling it to be implemented over thermal energy storage bottom up economic evaluations. To achieve this, two proven applications, molten salt storage for concentrated solar power and ice thermal storage for building cooling, were examined as the basis of the bottom up state of the art calculation models. It was found that in the ice storage case, the models were often done in a hybrid bottom up-top down approach which limits a fully detailed cost analysis. Instead these are referred as case studies instead because of the few elements needed in their calculation. The constructed specialized models and case studies are then compared against other external sources to validate the proposed economic analysis procedure. The numerical results showed some discrepancies when compared to external resources. A compilation of a general bottom up cost model with detailed step by step model to perform a bottom up calculation for thermal storages is finally proposed in this work.

  • Maher, Mario
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Kader, Rahand
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Using Online Communities and User-Generated Content for Innovative ProductDevelopment in the Gaming Industry2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Information from users on the internet come in different forms and shapes, e.g. videos, content on social media, reviews and other interactive platforms where information can be shared. The information on these platforms have the potential of helping developers gain a deeper understanding about users’ behavior, problems and needs for the purpose of capturing value and implementing it to increase the chance of successful product development. This paper aims to explore the role of User-Generated Content in New Product Development and how User-Generated Content can be used from idea to prototype. This is achieved by setting up aprocess for capturing customer value with the help of user information that is shared on the internet. Information on the internet can give an accurate understanding of customers’ needs which allows for a valuable idea capturing process. Information was gathered with the method of collecting information by monitoring and communicating with people on different online platforms. Based on the acquired information from users, a pain for customers with cold hands while gaming is discovered. From the understanding of the problem, a concept is derived as a possible solution. The concept is in the form of a prototype that is a possible suggestion for a new product to be developed – a gaming mouse with heat. The process which brought forward the new prototype set the foundation for this report. The result of the report is a process of how to operate with users on the web to generate new ideas for New Product Development, ideas that likely are more aligned with customer needs compared to traditional New Product Development processes.

  • Bütepage, Judith
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, Perception and Learning, RPL.
    Kjellström, Hedvig
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, Perception and Learning, RPL.
    Kragic, Danica
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, Perception and Learning, RPL.
    A Probabilistic Semi-Supervised Approach to Multi-Task Human Activity ModelingManuscript (preprint) (Other academic)
    Abstract [en]

    Human behavior is a continuous stochastic spatio-temporal process which is governed by semantic actions and affordances as well as latent factors. Therefore, video-based human activity modeling is concerned with a number of tasks such as inferring current and future semantic labels, predicting future continuous observations as well as imagining possible future label and feature sequences. In this paper we present a semi-supervised probabilistic deep latent variable model that can represent both discrete labels and continuous observations as well as latent dynamics over time. This allows the model to solve several tasks at once without explicit fine-tuning. We focus here on the tasks of action classification, detection, prediction and anticipation as well as motion prediction and synthesis based on 3D human activity data recorded with Kinect. We further extend the model to capture hierarchical label structure and to model the dependencies between multiple entities, such as a human and objects. Our experiments demonstrate that our principled approach to human activity modeling can be used to detect current and anticipate future semantic labels and to predict and synthesize future label and feature sequences. When comparing our model to state-of-the-art approaches, which are specifically designed for e.g. action classification, we find that our probabilistic formulation outperforms or is comparable to these task specific models.

  • Toljan, Irena
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Urban Space Index2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Architects and urban designers have a unique background to deal with the experiential qualities of cities. Quality of urban spaces is an essential aspect of livability (Southworth, 2003). The quality of urban spaces is important, specifically the interaction between buildings and the street, and it has been explored by Jane Jacobs, Jan Gehl and many more. BIM and CIM is new technology to analyze and design buildings and cities. With fast technology development, there are many options today on how to deal with the experiential qualities and make a 3D model using image-based input.

  • Pousette, Hedda
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Investigation into Melting Characteristics of Hydrogen-Reduced Iron Ore Pellets2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    What kinetic and thermodynamic characteristics are established in a melt of hydrogen-reduced iron ore pellets? The pellets contain self-fluxing slag components which upon melting form an initial slag. Refining capabilities of this slag, such as dephosphorization power, are investigated in a lab-scale vertical furnace. Understanding the initial slag and the reactions taking place when hydrogen-reduced iron ore pellets melt is important for future optimization of ingoing raw materials as well as industry scale process design.

    A sample of either crushed hydrogen-reduced iron ore pellets or a powder mixture representative of iron ore pellets in terms of composition was melted in a lab-scale vertical furnace. The sample was lowered into the argon atmosphere furnace which had a temperature of 1600°. The sample was kept inside a magnesia crucible with a molybdenum loosely-fitted lid. The purpose of the lid was to fix the oxygen partial pressure. The reduction degree of the pellets or corresponding powder mixture as well as the total melting times were varied.

    XRF and OES analysis were employed to find the composition of the slag and metal phases, respectively. SEM analysis was employed to investigate phases present in the slag. Comparison of melted iron ore pellets and corresponding powder mixture show that powder can be employed to represent reduced iron ore pellets accurately. It was found that reduction degree strongly impacts both phosphorus and vanadium distributions as well as the types of phases formed in the slag fraction. During melting, almost all of the Vanadium and most of the Phosphorus content goes to the slag fraction. At lower reduction degrees, dephosphorization is greater; however, the Phosphorus content in the steel is still quite high at 130 ppm or higher. Modification to the amount and/or composition of the self-fluxing slag is suggested to reach lower levels of phosphorus in the steel.

  • Wolfert, Pieter
    et al.
    Kucherenko, Taras
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, Perception and Learning, RPL.
    Kjellström, Hedvig
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, Perception and Learning, RPL.
    Belpaeme, Tony
    Should Beat Gestures Be Learned Or Designed?: A Benchmarking User Study2019In: ICDL-EPIROB 2019: Workshop on Naturalistic Non-Verbal and Affective Human-Robot Interactions, IEEE conference proceedings, 2019Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a user study on gener-ated beat gestures for humanoid agents. It has been shownthat Human-Robot Interaction can be improved by includingcommunicative non-verbal behavior, such as arm gestures. Beatgestures are one of the four types of arm gestures, and are knownto be used for emphasizing parts of speech. In our user study,we compare beat gestures learned from training data with hand-crafted beat gestures. The first kind of gestures are generatedby a machine learning model trained on speech audio andhuman upper body poses. We compared this approach with threehand-coded beat gestures methods: designed beat gestures, timedbeat gestures, and noisy gestures. Forty-one subjects participatedin our user study, and a ranking was derived from pairedcomparisons using the Bradley Terry Luce model. We found thatfor beat gestures, the gestures from the machine learning modelare preferred, followed by algorithmically generated gestures.This emphasizes the promise of machine learning for generating communicative actions.

  • Renwar, Rand
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Design and analysis of wing mounts for a Formula Student racecar2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report covers the concept production of the mounts for a rear wing of a Formula Student racecar. A structural analysis was also executed of the whole wing. KTH Formula Student’s aerodynamical group requested that this would be done since this part would be better done if it was to be done by someone who inherits better mechanical knowledge.

    The first part of the development process was to study the mounts for different types of racecars, and to later do an evaluation matrix to find the best suitable concept. A further development of the chosen concept was later done, by also performing more evaluation matrix’s that covered material, attachment and manufacturing. Studying literature was essential for this process.

    Finally, the mounts for the rear wing was designed whilst also performing numerous structural analyses in order to optimize the results. It was essentially the results of the analyses that shaped the final design of the whole wing.

  • Mallari, Joy
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Penttilä, Roine
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Design för möbler i framtidens förskola – Ett möbelset som främjar lärandet2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis was to develop a concept for a furniture-set that fits in with the preschools of the future, as well as to deliver CAD models and manufacturing documentation. According to a quantitative definition, this furniture should be able to promote the learning ability of the user, regarding function, safety, and accessibility.

    The task was started at Furnea's initiative to enter the furniture market in central Sweden and the Stockholm area with a new product that can meet the needs that are characterized by future sustainable preschools.

    The work was done in four different phases; planning, fact collection, implementation, and analysis.

    During the planning phase, structuring and methodology of the entire work was established.

    In the fact-finding phase, literature studies were conducted regarding educational orientations, environment, safety, ergonomics, and materials. Interviews of pre-school educators regarding the current use of tables in the preschool, and on companies concerning furniture manufacturing and preschools, were also conducted.

    The implementation phase uses the collected data to create a functional analysis and requirement specification for the furniture design, and then come up with a concept on the furniture. The phase also includes constructing the concepts with CAD and 3D printing.

    Analyses were used to bring out the concept that best meets the user's needs and modify the concept to the result. For this purpose, screening matrices, simulation programs for making strength calculations, and DFMEA, an error cause analysis for product development, were used.

    The result of this work is presented with figures and descriptions of the furniture.

  • Ye Årfelt, Julia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Yousef, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Minskning av kvalitetsbrister i rullagertillverkning – en studie vid SKF Göteborg2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    SKF internal data systems contain production data that has been collected in operator reports. One of the categories in these reports - Scrap & Rework - is directly connected to non-quality issues. Currently, this data is not used for any specific purpose. Large amounts of data are therefore collected and stored with no actual benefit to the company. A consequence of this is that scrap groups for different defect types and the location where defects are found are incorrectly categorized. The purpose for this thesis project was to make suggestions for minimizing non-quality product in one of the channels at the RK factory at SKF Gothenburg. The channel chosen is called RR04. The purpose was further to suggest new defect type names so operators more correctly can report non-quality product. This would make internal data more reliable and useful. Finally, the results from channel RR04 were validated for replication on another production channel at the same factory. To accomplish the project, the following methods were used: data collection from the internal data system, observations of individual operations at RR04, and interviews with related internal personnel involved with this channel. In addition, a root cause analysis and a validation were performed. The defect type codes used at RR04 cause confusion, waste of time, and unreliable data. The results from this project show that the operator reporting system is designed in such a way making probability large for defect codes to be reported incorrectly. This is also true for codes used for the locations where defects are found. The validation shows that results obtained at RR04 can be replicated into other channels in the same factory.

  • Lidén, Linnea
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Melander, Anders
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Problem för pollinatörer och dess påverkan på rapsskörden2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The sound of buzzing insects have become more scarce in the last several years and there is an overhanging risk that There will be a major decrees of them in the future. There is some scientific research that claims so, and that is worrying. A big part of the insects could be endangered and that would mean that the existence of ecosystems is at great risk. Farming in Sweden relies on several ecosystem services from pollinators, mainly provisioning and regulating. There are some cultural services from pollinators as well, that mostly affects outdoor life and the picking of berries among others. Some of the important pollinators are bumblebees and bees. Out of the 299 wild species that live in Sweden a third is threatened. Farmers are in need of pollination of the crops that don't self-pollinate, these crops are mainly fruit and vegetables but also oilseed rape. Oilseed rape is to some extent self-pollinating, but research shows that the yield ripens more evenly and the turnover of the crop is increased by a higher level of presence in the field by pollinators. This is of great interest for the farmers to make their business profitable, therefore they should work to preserve the ecosystem services that pollinators contribute with.

    This report attends the situation of pollinators in Sweden and how they contribute to ecosystem services, it's focused on red-listed species and their threats and problems. Also how the presence of pollinators affects the yield of rapeseed oil is investigated to try to estimate the value of pollinators. A smaller case study was conducted to further see how the conditions for pollinators are in a limited area. A literature study has laid the path for this study and it has been limited to the data available. for pollinators information about bees and bumblebees have been available, and a geographic limitation to Öland and to an area outside Gårdby was made.

    A small case study was conducted to further show the condition of pollinators in a limited area. It was shown that the observations of pollinators were sporadically conducted and there was a lack of knowledge in the chosen area. Therefore it's important to further increase the interest and knowledge about how humans affects and uses the ecosystem services from pollinators every day.

    The identified threats was a change in land use, to such an extent that it affects the conditions of surviving. It could be caused by intensified farming were the access to sufficient food is no longer available to pollinators. Increased land use changes the natural habitats where pollinators build their nests, either because they overgrow or they are exploited to uninhabitable ground. A solution to this is ecological farming where natural regions contribute to a greater biodiversity in the landscape are seen as a resource and preserved. The increased intensification of farming land will decrease if a large part of the farming is done ecologically. The second threat was pesticides in general, it has been shown that it could have a negative impact on pollinators, and mostly the larva’s and eggs. In addition to that, the recommendation on how long to test for the effects of a pesticide is very short. These problems with pesticides have two solutions, one was an increase in ecological farming and also to conduct longer test periods for pesticides. Other potential threats that were identifies was the overhanging climate change, conditions would drastically change. A presence of domesticated pollinators could be rival to native pollinators and lead to a decrease of native pollinators.

  • Bast, Sigvard
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Schück, Fredrik
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Laver, då som nu: En fallstudie om efterbehandlingens vikt vid planering av gruvor2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An increasing demand for copper has led to the prospecting of areas with low copper content. One such area is Laver in Älvsbyn municipality where Boliden Mineral AB wants to establish an open pit mine in what was once an old mining settlement. The planned mine causes conflicts with nearby reindeer husbandry, Natura 2000-areas and has consequences for the environment as well as the society in Älvsbyn. This report examines the effects of both the old and planned mine in Laver, with a focus on the after-treatment and how the concerned agents become affected by a new mine. A scenario analysis was made by gathering information from literature, interviews and a field work at the mining site. This scenario analysis compares and values the impact on the local environment, reindeer herding and society. The planned mine will be on a larger scale than the old one and will therefore have to take more aspects of future impacts into account. If a mine is established in Laver, most of the waste can be taken care of by Boliden. There are some ideas on how the after-treatment can meet the needs of the municipality, but the reindeer husbandry is at great risk of vanishing from the area. Hence, it’s of importance that future consequences are weighed from a holistic perspective where the interests of all agents are met.

  • Kortenius, Jacob
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Wallhed, Niklas
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Studie i att sammanställaenergiplaner för att synliggörakraftbehov 2030: En explorativ och formativ undersökning2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Energy Agreement from 2016 is comprised of several goals for the forming of the Swedishpower system. The Swedish power system should be ecologically sustainable, competitive andbe able to supply power without interruption. Furthermore, this agreement also involves a goalof a 100% renewable power generation in 2040, which has been analyzed in this report. Theaim with his report is to highlight problems that might occur in the case of an unbalanced powersystem with respect to ecological sustainability, competitiveness and safe supply. The reportalso aims to raise awareness amongst the actors in the Swedish energy system and highlightproblems in the future. The main scientific method used in this report is a formativeexamination where interviews with the power company representatives gave a deeperunderstanding of the power system as of now, but also in the future. Another scientific methodused has been an explorative examination throughout the literature studies, where these twomethods combined has enabled explanations and causations. The foremost source ofinformation are scientific studies connected to the power system, where KTH’s database Primoand Google Scholar has been used as a primary medium for searches. Authorities and NGOs,such as the Royal Swedish Academy of Engineering Sciences (IVA) and North EuropeanEnergy Perspectives Project (NEPP), has also been used as a primary source of information.The results show problems connected to lack of effect, inertia as well as a decrease of plannablepower through the closure of nuclear power plants and thermal power plants due to newtaxation. The result also shows that an introduction of wind power to the Swedish power systemalso decrease the national independence and rely more on import of power, mainly fromGermany which have a higher share of fossil elements. In other situations, it also leads to ahigher export where Swedish power removes fossil elements in other countries. Furthermore,a long-term strategy and increased cooperation between the systems actors is crucial for thedevelopment of the future energy system with focus on implementing system services whichare decreasing with the decrease of plannable power. The share of wind power is expected torise to 2030, at the same time the plannable power, nuclear and thermal power, is expected todrop. The national goal of a renewable power generation is reached by the year 2040 is notlikely, where the current nuclear power reactors will remain their entire economic life spanwhich spans to 2045, with chance of life span extension.

  • M. Kösanlioglu, Jiyan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Emad, Mark
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Global affärsmodellering och digitalisering2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis degree project has been submitted for the degree program in Mechanical Engineering, Industrial Business Administration and Manufacturing, at KTH Royal Institute of Technology, Department of Sustainable Production Development. The study has been carried out on behalf of Alfa Laval AB, Business Unit GPHE, during the spring term 2019.

    The goal of this thesis has been to perform a survey of interests in the digital ecosystem, identify customer needs and market players in the field of predictive maintenance and connected products, along with suggesting on possible business models. Alfa Laval’s expectations have been to receive anover view of the currently emerging digital ecosystem and that the project should support the fulfillment of customer needs.

    Interviews and research of stakeholders have been central methods during the implementation. In the project an investigation was made of different companies to design a mapping model. The study included in-person interviews with market players and end customers to support the survey on cases in which connectivity creates customer value and also to get an overview of strategies used by different market players in digitization. The literature studies have covered topics regarding Internet of Things, Connectivity, Industry 4.0, predictive maintenance and business modelling.

    The result has shown that the most common customer needs are asset status monitoring, predictive maintenance, higher productivity and others, all of which are related to the customer’s desire of achieving cost reduction. For the digital ecosystem, it can be stated that the current situation is fragmented and that there is a constant emergence of new solutions with quick implementations and new players trying to position themselves in the market. The study also shows that connectivity contributes to the development of new types of services, thus causing an increased need of implementation of new service-oriented business models with new revenue streams based on subscriptions.

  • Babiker, Dina
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ahlstrand, Matilda
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Experimental Study of Mineral Carbonation of Wollastonite for Increased CO2 Uptake2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The cement and concrete industry stand for approximately 8% of the global CO2 emissions. The demand of concrete and cement is expected to increase rapidly with the growing world population and increased urbanization. This makes it of the utmost importance for the industry to try to mitigate its emissions. One way to reduce the industry’s environmental impact is by mineral carbonation curing through which CO2 can be sequestered in the concrete. This investigation studied the CO2 uptake of wollastonite (CaSiO3) which can be used for mineral carbonation. The CO2 uptake of different brands of wollastonite powders for different temperatures, pressures and water to solid ratios were tested through carbonation, and the samples were then analyzed through XRD, SEM and particle size analysis. The results showed large differences in CO2 uptake between the brands of wollastonite powders. They also indicate that lower temperatures lead to higher CO2 uptake but also possibly slow down the reaction rate and that higher CO2 pressures seem to increase CO2 uptake though the effect is small.

    There was significant variation of the effects of the water to solid ratios on CO2 uptake between the tested brands. The morphology of the powders also seemed to be of little relevance as an amorphous and crystalline powder were the two best performing powders, similarly particle size is not indicated by the result to have a large effect on CO2 uptake, though further studies are required to fully determine the effect of the morphology and particle size.

  • Gustafsson, Amelie
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Wiklund, Hannes
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Batterier i kraftsystemet: En studie i batteriers potential som energilagring för stöd av intermittenta energikällor i det nationella kraftsystemet2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The development of the modern society and the global continuously accelerating energy intensive way of living is putting stress on the climate. In order to achieve the UNs set of sustainability goals, including reduced emissions and more efficient use of energy, vigorous actions in the global energy system is required. To increase the share of clean and modern energy generation a larger quantity of solar and wind power is required. Due to weather dependency these resources generate intermittent electricity which will put new challenges on the grid.

     

    To facilitate the implementation of intermittent energy sources on the national grid and in smaller energy systems this report aims to investigate current prerequisites on integrating battery energy storage systems and intermittent resources to increase the share of clean energy sources in the power system. Current prerequisites are presented as the result of an extensive literature study where the electrical grid, promising battery technologies, financial incentives for battery energy storage and future potential is examined.

     

    A global commitment to increase the share of renewable energy sources using battery energy storage system in the global energy system is identified. Furthermore, battery energy storage systems are shown to have great potential in limiting the negative impact of intermittent energy sources on the electrical grid. This potential is currently being limited by existing political control means and the design of the electricity market such that small producers are benefitted by directly supplying the grid with excess electricity instead of using energy storage. With a growing share of intermittent power generation these limitations are expected to ease and battery energy storage systems in connection with power production becoming more profitable.​

  • Baban, Hanna
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Grauning, Olivia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Using Fetal Myocardial Velocity Recordings to Evaluate an AI Platform to Predict High-risk Deliveries2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Diagnosing abnormal fetal cardiac function using ultrasound is a complicated procedure which makes it difficult to obtain high quality results from ultrasound examinations that are performed shortly before delivery. Color tissue Doppler imaging (cTDI) is the echocardiographic technique that has been used to obtain the data for this project. Subtle changes in the fetal cardiac function caused by a variety of complications can possibly be detected using cTDI. Fetuses suffering from these complications are often involved in high-risk deliveries. Combining the data obtained from cTDI with Artificial Intelligence (AI) may improve precision and accuracy when it comes to diagnosing pathological conditions involving fetal cardiac function before delivery. AI uses machines to perform and execute tasks that are characteristic of human intelligence. AI can be achieved by using deep learning. Deep learning uses algorithms called artificial neural networks that are inspired by the biological structure and function of the human brain. The neural networks classify information in a similar manner to the human brain. A platform that uses deep learning can make statements or predictions based on the data fed to it. The AI platform Peltarion uses deep learning to perform tasks. The aim of this project was to use Peltarion to evaluate the possibility of predicting high-risk deliveries with abnormal perinatal outcome by using data obtained by cTDI velocity recordings of the fetal heart. The data included myocardial velocity recordings from 107 pregnancies, out of the 107 pregnancies 82 of the babies were born healthy while 25 babies had an adverse perinatal outcome. The data was uploaded in the platform and three models were built and trained in order to evaluate the performance of the platform using the data. The parameters that have been used to determine the results are loss, accuracy and precision. The results showed that the accuracy parameter was measured to be 0.8 in all cases which means that the model correctly predicts if a fetal heart is healthy or likely to have an adverse outcome 80% of the time. The precision parameter was measured to be around 0.4 which means out of all the times the model predicted a fetal heart to have an adverse outcome, only 40% truly had an adverse outcome. It was concluded that a substantially larger amount of evenly distributed data is required to appropriately evaluate the possibility of using fetal myocardial velocity recordings as data for the AI platform Peltarion to predict high-risk deliveries.

  • Pettersson, Emil
    KTH, School of Industrial Engineering and Management (ITM), Sustainable production development.
    Kartläggning och förslag på arbetsmetodik inom ett beredningsflöde2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is the result of a bachelor thesis within the area of mechanical engineering, management and production at the Royal Institute of Technology. The study was conducted at the defense and security company BAE Systems Hägglunds AB in Örnsköldsvik, Sweden. The study has been conducted on location which has been essential for the feasibility of the study. The assignment and the goals of which it should accomplish, as well as within which boundaries has been assigned by the section for Prototype and Hulls (Swedish P & S). Set goals include mapping the fault effects which occurs when process times doesn’t match that of which has been planned and assigned for specific work orders, methods for feedback between the workshop and ERP-systemfor more accurate future processes. As well as methods for calculation of process times for all components in a batch since the first ones tend to require more time.

    The section of Prototype and Hulls produce and delivers hull components for all of BAE Systems Hägglunds families of vehicles. It’s necessary for the vehicles to continuously being developed due to customers’ demands for them to be able to compete on the global market. As a result the manufacturing of prototype components is essential for the company’s ability to gain customers, which is why it’s up most important to beingable to deliver prototype components for R & D rapidly. The section for Prototype and Hulls lacks standardized methods for the production preparing and planning. This results in components that are too expensive and late. In a long term this means that employees doesn’t trust the ability of the business and in some cases, develops local improvements, putting the company at risk of developing sub optimizations.

    The study discusses the fault effects discovered by the mapping process, which is being described as a result of not using standard methods. The study recommends BAE Systems Hägglunds to implement a standardized method towards the NC-programming where the programming is conducted before the preparer creates a work order. Since BAE Systems Hägglunds wants to calculate the required time for all componentsin a work order the study recommends intercommunication between different sections to exchange experience and work methods with each other.

  • Boström, Caroline
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Messler, Olivia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Design and Evaluation of a 3D Printed Ionization Chamber2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Ionizing radiation is often used within medicine for diagnosis and treatments. Because ionizingradiation can be harmful to the body, it is important to know how it affects the tissue. Dosimetryis the study of how ionizing radiation deposits energy in a material. To measure how much ionizingradiation is deposited in the body, gas-filled detectors are often used. An ionization chamber isa type of gas-filled detector and exists in different shapes and sizes, depending on what kind ofmeasurements it is made for. Because ionization chambers are relatively expensive, it is often notpossible to buy one for each type of measurement that is to be done. This results in ionizationchambers being used for measurements they are not optimized for. This report evaluates thepossibility of 3D printing ionization chambers to make it easier to optimize them for specificmeasurements. The process included creating models of ionization chambers using CAD-software,slicing them and then 3D printing them. The 3D printed models were then brought to the SwedishRadiation Safety Authority for measurements. The ionization chambers were connected to highvoltage, and exposed to ionizing radiation in the form of high-intensity gamma-ray fields. Theoutput current of the ionization chamber was measured, which is proportional to the field intensity.The results were similar to those of a commercial ionization chamber. The conclusion is that it ispossible to 3D print ionization chambers. However, to get more accurate results, the design has tobe further optimized and more measurements need to be done.

  • Chen, Chao
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Bhamare, Yogesh Vishwas
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Life Cycle Cost Analysis and Optimization of Wastewater Pumping System2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Different attempts have been made to facilitate successful operation of Wastewater Pumping (WWP) system. The WWP units which are already existed in different parts of the world have been studied to identify its success, failure and different parameters associated with its suboptimal performance. The performance of WWP depends on three parameters namely pump, hydraulics, control system and pump station. These parameters are interdependent and must be carefully matched to achieve efficient WWP system. Nowadays the scenario has changed where organizations has started looking increasingly at the total cost of ownership, another way of saying Life Cycle Cost Analysis (LCCA) and recognizing the need to get most out of their equipment purchase.

    The master thesis includes theory part which describes the different parameters associated with WWP unit especially focusing on Xylems WWP system. This thesis is an attempt to help companies to know how LCCA could be productive management tool in order to minimize maintenance cost and maximize energy efficiency

    The study reported in this thesis work has been conducted to shed light over the use of Life Cycle Cost Analysis in WWP system. The current study tries to suggest and assess an adopted approach to ensure successful and efficient operation of WWP system with lowering energy demand and decrease in maintenance cost. Initial cost, Maintenance cost and Energy costs are important issues in the operation of WWP system since they are responsible for total cost over time. Therefore, description of each cost, formulas necessary for LCC calculations, data and survey structure, material and energy flow has been described.

    This work also aims to provide an extensive literature review, different survey and data collection techniques, analysis of collected data, statistical modelling, customer interaction by questionnaires and an interview with experts were used. LCC calculations were used to support the design and selection of most cost-efficient WWP system.

    Therefore, the given thesis work is an attempt to achieve better functional performance, improve existing design principles associated with WWP System, contribution to asses economic viability, support decision making to enhance operational quality to achieve efficient and successful WWP system.

  • Sahal, Sahal
    KTH, School of Engineering Sciences (SCI).
    Mikrobearbetning av Kollagen Baserad Hydrogel Med en Femtosecond Laser För Vaskulär Vävnadsteknik2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Three-dimensional cell cultivation (3D models) has been shown to be a more effective way of mimicking in vivo cells compared to the 2D models used today. One challenge that prevents the wide use of 3D models is the limited diffusion of oxygen within them. Only cells located close to the surface survive. The introduction of a vascular system would counteract this problem and aid in making 3D models viable for drug development research. The aim is to study the possibility of using a femtosecond laser to induce perfusable channels into collagen-based hydrogels. This is done by experimentally processing the hydrogel with a femtosecond laser and studying if visible manipulation is made. The results show that perfusable channels can be induced into the bulk of the collagen-based hydrogel. Further results also suggest how the size of the channel varies with different parameters. Femtosecond lasers seem to be a good candidate for creating artificial vascular systems and advancing current methods in drug development.

  • Gabrielsson, Linnea
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Hasan, Zanwer
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    The Influence of Agile Project Management on Knowledge Sharing in a Team: A Study Conducted at an Engineering Consultancy Firm2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Several studies have been conducted regarding the importance of knowledge managementwithin an organization. Furthermore, due to the successful outcome of the implementation ofagile project management approaches within the IT-sector, they have been implemented inother sectors as well. The purpose of this master thesis is to examine how agile projectmanagement influences knowledge sharing within a project team in an engineeringconsultancy firm.The study was conducted through a qualitative approach at a Swedish engineeringconsultancy firm. Data was gathered from observations of project meetings and interviewswith consultants involved in projects that have implemented agile methods. Moreover,interviews were conducted with external experts with expertise in agile project managementin order to obtain additional perspective. Semi-structured interviews were conducted withmodified questions for consultants and agile experts. Thereafter, the empirical findings wereinterpreted by the theoretical concepts in order to sum up the report with conclusions.Firstly, the study confirmed that the implemented agile methods influence explicit knowledgesharing whereas the tacit knowledge sharing is not enabled sufficiently within a project team.Secondly, it could be concluded that the implemented agile methods influence projecttransparency, team-collaboration and communication. This positive influence enablesknowledge sharing within a project team. Lastly, the conducted research concluded that agilemethods influence consultants to share knowledge due to the nature of required inputs inthese methods. Since tacit and explicit knowledge sharing and its documentation is equallyimportant for the success of a project and the consultancy company subsequently, thisresearch has concluded that a hybrid of traditional management approaches and agile methodsis essential to share and document both types of knowledge for alike consultancy firms.Consequently, the research findings resulted in recommendations which aim to improve theprocess of creating and implementing a hybrid of management approaches.

  • Tähtinen Dahl, Viktor
    KTH, School of Engineering Sciences (SCI).
    Elbil utan elnät - Utnyttjandet av omgivning och klimat för etablering av elbil2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Some of the worlds most hostile and remote locations may seem like unsuitable places for a modern battery electric vehicle when range anxiety is a real issue in countries with a well developed power grid for example Sweden. Belonging to these remote locations are the dessert areas of Africa, Austalias outback along with the steppes of Siberia. The purpose of this thesis is to investigate the possibilities to modify a modern electric or fossil driven vehicle to function completely without the access to a power grid and solely rely on renewable energy mainly from the sun. Data on the amount of sun hours in Africa and Austalia was collected and together with specifications for solar panels an average power output of 123, 67 W/panel was calculated. Further for the analysis a theoretical car, a pickup truck, was chosen mainly because of the wide spreaded usage in the areas but also because of the ability to place two panels on the truck bed. The total area of the two panels was assumed to 4m2 and could the be estimated to charge a 30 kWh battery in 121.3 hours. To decrease the amount of time taken to charge a battery of that size the option to place panels on a small roof was chosen instead of the truck bed. Still completely without supply from the power grid the panels on the roof manage to charge the battery in 16.7 hours which means a 30 kWh battery can be charged within two days of optimal sunshine. In other words there is no efficient way to charge a battery using only solar panels mounted on a vehicle. Instead a larger area must be used, for example a house roof, to charge a battery within reasonable time without the need for a power grid.

  • Waldemarsson, Mathias
    KTH, School of Engineering Sciences (SCI).
    Igenkänning av filbyte och undvikande av kollision i KTH PlatoonSim2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The goal of this project was the design of an algorithm for detection of an unsafe lane change (cut-in) and the avoidance of a collision within KTH PlatoonSim, a simulator of autonomous vehicles developed at KTH. The solution proposed is the introduction of two new ECU classes: A Cut-in Detector (CID) and a Cut-in Braker (CIB). The CID is responsible for detecting an unsafe lane change and the CIB is responsible for calculating the necessary brake command for safe but smooth braking. Testing reveals that this model is successful at avoiding collision at ordinary motorway speeds.

  • Heintz, Alfons
    et al.
    KTH, School of Engineering Sciences (SCI).
    Thunberg, Jonas
    KTH, School of Engineering Sciences (SCI).
    Extrahering av återkommande beteendemotiv från videoinspelningar av naturligt beteende2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report we demonstrate the usefulness of hidden Markov model estimation as a method to construct models of mouse behavior. We used a neural network to retrieve positional data of different body parts from overhead video recordings of lone mice in an enclosure. We then extracted features such as velocity and elongation from the positional data and used an implementation of the Baum-Welch algorithm to fit hidden Markov models to the feature data. We could identify recurring behaviors such as "running next to wall" and "investigating wall" among the estimated states in several different mice, which was consistent with what we could see in the actual videos. We thereby demonstrate that hidden Markov model estimation by the Baum-Welch algorithm can be utilized to automatically find models of mouse behavior.

     

  • Injan, Nattapol
    et al.
    KTH, School of Engineering Sciences (SCI).
    Norström, Arvid
    KTH, School of Engineering Sciences (SCI).
    Heterogena Multiskalmetoder för Högt Oscillativa och Dissipativa Ordinära Differentialekvationer2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report we study a class of numerical algorithms under the name of heterogeneous multiscale methods. We present an introduction to the subject and analyze the stability and accuracy of a few implementations of dissipative and oscillatory problems. Furthermore, we demonstrate its superiority in comparison to tradtional numerical methods for these types of problems. Finally, we also present an implementation on a larger problem, namely the well known three-body problem.

  • Falk, Simon
    KTH, School of Engineering Sciences (SCI).
    Finita differens-metoder för reservoarsimulering2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Reliable computational tools are important in general to understand the vari- ous processes around us, and the simulation of flow in reservoirs in particular is vital for responding to some of our time’s urgent demands. For instance, stable groundwater basins, sustainable oil extraction, and safe nuclear waste repositories all require reservoir simulation. In this thesis, two methods for discretizing Poisson’s equation with variable coecients will be implemented and compared. This equation is a partial di↵er- ential equation that describes stationary, incompressible fluid flow in a porous medium: an ubiquitous process in reservoirs. In the first method, Taylor ex- pansions are used for discrete points (the Finite Di↵erence method), and in the second one, the concept of flux makes it possible to state continuity relations be- tween cells (the Finite Volume method, here the O-method). The methods yield di↵erent stencils which may be thought of as recipes for discretizing the equa- tion. While the former is a derived to obtain a certain numerical consistency, the last method is derived on principles of local flux conservation. The stencils are judged by their convergence rate, and two tests are per- formed to see which is the more accurate stencil. Both are implemented on a Cartesian grid, and it is measured how far the numerical solutions are from the analytical one. The tests are carried out with a full, heterogenous permeability tensor, which in case 1 varies smoothly over the whole domain. In this case it is found that the error series of both stencils are proportional to h2, where h is the step size. The FDM stencil reduces the error with 12% compared to the FVM stencil. In case 2, an imposed discontinuity ”gap” in the permeability leads to a convergence rate in the interval [0.73, 1.11], but the FVM stencil has a higher convergence rate than the FDM stencil. Curiously, the convergence rate are not correlated to the magnitude of the gap. Experiments using other grid refinement techniques are suggested to carry the comparison further. The results illustrate that in the case of continuous media, a straight-forward Taylor expansion of the equation is converging with the same convergence rate as the more elaborate O-method. The testings can furthermore verify that the O-method converges to second order for heterogeneous media, which was proved for homogeneous media by Aavatsmark. Moreover, tests on discontinous media show that the O-method performs slightly better than the Taylor method while losing the second order convergence.

  • Barchin, Alexander
    et al.
    Sedighi, Navid
    Alternative methods to prevent thermal cracking in concrete2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the construction industry, concrete is the most common material, because of its good properties such as compressive strength and endurance. Concrete is a composition of several different materials where one of the main components is cement. When the hydration process starts, large amount of heat is generated. This leads to temperature rise within the structure. The heat development that takes place can become critical for massive structures such as dams and power plants, where natural cooling is not sufficient. This in combination with internal and external restraint resulting in tensions causing cracks in the structure. By controlling the temperature development, one can reduce the risk of cracking in massive structures. The controlling is divided into pre-cooling and post-cooling. Reduction of the risk for thermal cracking can be done in different ways. Parts of the cement in the concrete can be replaced by a pozzolan material such as silica fume, blast furnace slag or fly ash. Another method is to increase the size of the aggregates which makes it possible to reduce the cement content with remained strength. Cooling the aggregates or use of ice can also be used as a pre-cooling methods. The most common post-cooling method is the installation of cooling pipes. Pipes are installed between the reinforcement bars, in which one then pump through with cold water. This thesis aims at practicing the methods examined by Lagundžija & Thiam (2017). Focusing on those results that proved to be most effective, i.e. the combination of fly ash, ice and large aggregates. The results retrieved during the tests shows a significant increase in the compressive strength when using a combination of fly ash, ice and large aggregates. This gives us the opportunity to reduce the initial cement content. Reducing the cement content is the most effective factor regarding the heat development. When replacing amounts of the water with ice, it can be seen that the initial casting temperature was reduced. Further studies can be done to find the right amount of reduction of the cement that can be done while maintaining the required compressive strength.

     

  • Johnsen, Sebastian
    KTH, School of Engineering Sciences (SCI).
    Komponentanalys för integrerad kvantfotonik på chip2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Being able to control nature on the quantum level promises to unlock technologies far beyond capabilities of today. In the race for achieving such technologies several avenues are being pursued, each with their benefits and drawbacks. One of these is quantum photonics. With the possibility of on-chip implementations, making use of already established methods of production, and the possibility of developing on demand entangled photons, a scalable quantum photonic circuit might not seem too far away. This report aims to facilitate the creation of a on-chip scalable photonic platform by evaluating the different components needed to realize quantum photonic integrated circuits.