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  • Hsieh, Yves S. Y.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Harris, Philip J.
    University of Auckland.
    Xylans of red and green algae: what is known about their structures and how they are synthesised?2019In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, no 2, article id 354Article, book review (Refereed)
    Abstract [en]

    Xylans with a variety of structures have been characterised in green algae, including chlorophytes (Chlorophyta) and charophytes (in the Streptophyta), and red algae (Rhodophyta). Substituted 1,4-β-d-xylans, similar to those in land plants (embryophytes), occur in the cell wall matrix of advanced orders of charophyte green algae. Small proportions of 1,4-β-d-xylans have also been found in the cell walls of some chlorophyte green algae and red algae but have not been well characterised. 1,3-β-d-Xylans occur as triple helices in microfibrils in the cell walls of chlorophyte algae in the order Bryopsidales and of red algae in the order Bangiales. 1,3;1,4-β-d-Xylans occur in the cell wall matrix of red algae in the orders Palmariales and Nemaliales. In the angiosperm Arabidopsis thaliana, the gene IRX10 encodes a xylan 1,4-β-d-xylosyltranferase (xylan synthase), and, when heterologously expressed, this protein catalysed the production of the backbone of 1,4-β-d-xylans. An orthologous gene from the charophyte green alga Klebsormidium flaccidum, when heterologously expressed, produced a similar protein that was also able to catalyse the production of the backbone of 1,4-β-d-xylans. Indeed, it is considered that land plant xylans evolved from xylans in ancestral charophyte green algae. However, nothing is known about the biosynthesis of the different xylans found in chlorophyte green algae and red algae. There is, thus, an urgent need to identify the genes and enzymes involved.

  • Ahlin Marceta, Jesper
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, Philosophy.
    Nine Cases of Possible Inauthenticity in Biomedical Contexts and What They Require from BioethicistsManuscript (preprint) (Other academic)
    Abstract [en]

    Respect for autonomy is a main moral principle in bioethics. It is sometimes argued that authenticity, i.e., being "real," "genuine," "true to oneself," or similar, is crucial to a person's autonomy. This article collects nine cases in which the notion of authenticity has been or could be invoked in biomedical contexts. One recently developed theory aiming to provide normative guidance with regard to authenticity-related problems is applied when it is possible, while it is explained in detail why the theory is inept or impractical in the remaining cases. The article thus provides an overview of authenticity-related problems which may be helpful for autonomy theorists. Furthermore, it is argued that there is no universal problem of authenticity, but many problems, and that they may require various particular solutions rather than one universal solution. Among other things, it is suggested that bioethicists should explore non-ideal methodological approaches to authenticity-related problems to provide action-guidance with regard to them.

  • Ahlin Marceta, Jesper
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, Philosophy.
    A non-ideal authenticity-based conceptualization of personal autonomy2018In: Medicine, Health care and Philosophy, ISSN 1386-7423, E-ISSN 1572-8633Article in journal (Refereed)
    Abstract [en]

    Respect for autonomy is a central moral principle in bioethics. The concept of autonomy can be construed in various ways. Under the non-ideal conceptualization proposed by Beauchamp and Childress, everyday choices of generally competent persons are autonomous to the extent that they are intentional and are made with understanding and without controlling influences. It is sometimes suggested that authenticity is important to personal autonomy, so that inauthenticity prevents otherwise autonomous persons from making autonomous decisions. Building from Beauchamp and Childress’s theory, this article develops a non-ideal authenticity-based conceptualization of personal autonomy. Factors that indicate inauthentic decision-making are explicated, and the full concept is defended from three expected objections. The theory is then tested on a paradigm case which has concerned theorists and practitioners for some time, namely the possible inauthenticity of anorexia nervosa patients’ decision-making. It is concluded that the theory seems to be fruitful in analyses of the degree of autonomy of patients’ decision-making, and that it succeeds in providing reliable action-guidance in practical contexts.

  • ALDAJANI, WALEED
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Towards Nearly Zero-Energy Buildings Renovation: Case Study: Telefonplan2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The objective of this thesis is to investigate the potential for a nearly Zero-Energy Building (nZEB) renovation, its benefits for real estate owners in Sweden, and their ability to comply with the current Swedish definition of nZEB. The study is carried out in co-operation with the Swedish real estate company Vasakronan, one of the country’s largest real estate owners. Several energy-efficiency and renewable energy measures are implemented in a case study at the building complex Telefonplan. The improvement measures chosen are based on their proven cost-optimality and potential to bring the buildings to nZEB energy consumption levels, and are calculated using an array of tools; PVSOL, EED and Excel. The results are analyzed using Boverket’s regulation for nZEB, which was set for new builds. The economic performance of the renovation is analyzed considering capital and operational expenses, energy savings, and the increase in property value. The results show that Telefonplan failed to reach the Swedish nZEB targets with pre-selected energy efficiency measures. However, the financial results in terms of annual savings as well as raised property value can stand as a strong motivation for real estate owners to consider such investments.

  • Saameño Perez, Juan Jose
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Characterization of PLA and design of a 3D printed wing2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report describes the structural design of a wing for a Vertical Take Off  and Landing drone, in which all the structure will be built by fused deposition modeling of polylactic acid (PLA). To perform this de-sign, the material used is first characterized in different orientations using tensile stress tests, Image Correlation and MATLAB. These properties are then input in a MATLAB program specially developed for this project to obtain the optimum skin and spar thickness in the wing for certain fight conditions. Results are finally verified with a 3D model in CAD and scaled wings in bending tests.

  • Inegbedion, Ehimenmen Michael
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Stiffness Re-Design and Insert Solutions for the ZBee2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis presents a systematic approach to solving the problem of large deflections in the ZBee vehicle, proposing feasible insert solutions while reducing weight and increasing efficiency were possible.An experimental study was done on the structural deformations of a sample ZBee floor using highly advanced measuring instruments. Based on this background a finite element model was developed which simulates the experiment to a good level of correlation. Modifications were then carried out on the model to examine different factors which affect the stiffness and hence deflections experienced by the driver. Based on a systematic selection of alternative solution an insert analysis was done which gives initial design parameters for a new insert implementation.To improve the manufacturability and hence cost of the Zbee floor, a new floor design with simpler geometry was analyzed and further developed based on the stiffness properties studied on the old chassis.

  • Chacko, Noel
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Impact Resistance of CFRP Products2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis investigated the impact performance of CFRP products within the sports industry. The primary aim of this thesis was to evaluate different configurations, matrix system, and technologies to find the best performing solutions for impact. During this work, an extensive literature study was conducted and various solutions were reviewed. Further on, several tubes were manufactured, impacted and put through a 2 point bending test to find out the residual strength. It was found that TeXtreme R fabrics positively affected the impact performance when compared to conventional fabrics and UD depending on the placement location. Thin plies proved to be better than conventional plies. Newer technologies such as CNT stitching requires further investigation before it can be qualitatively assessed.

  • Anandito, Akhsanto
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Dynamic Analysis of Sinusoidal, Random and Shock Vibration according to Launch Environment for Small Spacecraft Development to Asteroid 2016-HO32019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The investment of space commerce is skyrocketing and it is predicted to be a nascent business in the future. The spacecraft demand has been growing not only for NASA and other space agency’s mission but also collaboration business between small space industries, academia, and scientific community. This glimpse brought an interest to a new investor, government, military, and manufacturing company to deliver their objectives efficiently. Nowadays, many startups compete embracing innovation and pioneering the novelty of space project beyond prodigious vision in an unprecedented way. Many players foresee that decreasing size of the rocket is an important key to survive and succeed in the space business. One of the efficient acts is lowering the launch cost. This can be achieved by designing a small size, lightweight and affordable spacecraft. Within this context, a Beyond Atlas Spacecraft which will be sent to Asteroid 2016-HO3, has achieved a wet mass of 20.85 kg with the size of 24.7 x 42.2 x 40.8 cm in stowed mode and 84 x 399 x 40.8 cm in unstowed mode. However, the drawback being light and small may lead to catastrophic failure due to resonance frequency events. According to past experience, the gyro of the Swedish national satellite was damaged during ground testing and it was suspected due to high amplification when the natural frequency coincides to the main structure resonance. Therefore, this work is focusing on a spacecraft development and a non-destructive structural analysis. The coupled-load analysis of a preliminary spacecraft design including sinusoidal, random vibration and shock analysis are calculated using FEM. This effort can reduce the risk of component destruction before laboratory testing as well as understand better the dynamic behavior of the spacecraft. The critical frequency in each orthogonal axis with base input from launch environment of the LM-3A Launch Vehicle was devised. The maximum stress, amplitude, and acceleration in accordance of qualification test criteria were evaluated and discussed.

  • Public defence: 2019-03-13 14:00 Konstantinbågen, Stockholm
    Mohagheghi Nejad, Mohammadreza
    KTH, School of Electrical Engineering and Computer Science (EECS), Computational Science and Technology (CST). Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.
    Interaction of sensory and motor signals in the basal ganglia in health and disease2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The basal ganglia, a set of deep forebrain nuclei, are among the brain regions involved in movement initiation and suppression. Although many studies have investigated the neural coding underlying these two aspects of movement, there are still questions that need to be addressed. In this thesis, I used computational models of motor thalamus and the basal ganglia at three different levels to improve the understanding of the neural coding our brain utilises to initiate and suppress movement. I used a Hodgkin-Huxley model of a thalamocortical neuron to investigate the transmission of a motor signal (i.e. movement initiation) from the basal ganglia output to the motor thalamus through post-inhibitory rebound spikes. I investigated the impact of pathological activity of the basal ganglia output (e.g. in Parkinson’s disease) and the impact of sensory responses in the basal ganglia output and cortical excitation to the thalamus on these signals. I showed that correlations in the basal ganglia output (representing pathological activity) disrupt the transmission of motor signals via rebound spikes by decreasing the signal-to-noise ratio and increasing trial-to-trial variability. In addition, I found that both the sensory responses and cortical inputs could either promote or suppress the generation of rebound spikes depending on their timing relative to the motor signal. Finally, in the model rebound spiking occurred despite the presence of moderate levels of excitation, indicating that rebound spiking might be feasible in a parameter regime relevant also in vivo.

    In addition to movement initiation, I investigated the role of basal ganglia in movement suppression using a spiking network model of the basal ganglia. I simulated a stop-signal task in the model by stimulating it with realistic patterns evoking movement-related activity in the striatum and substantia nigra pars reticulata (SNr) and evoking stop-related activity in subthalamic nucleus (STN) and arkypallidal neurons in globus pallidus externa (GPe Arky). I found that a Stop response in STN delayed initiation of movement that was detected by observing SNr activity. In addition, I showed that a Stop response in GPe Arky suppressed movement-related activity in the striatum and via direct pathway in SNr. However, the pattern of these suppressed movement-related activities did not match with previous experimental observations in successful Stop trials. I explained this mismatch using a biophysically detailed multicompartmental model of projection neurons in the striatum. I found that the long-lasting depolarisations at the level of the soma, resulting from dendritic plateau potentials evoked by clustered excitatory inputs at distal dendrites, could evoke movement-related activity in these striatal neurons. The inhibition from GPe Arky targeting the excited dendrites could fully suppress the movement-related activity matching with experimental recordings in successful Stop trials.

    In conclusion, the nigrothalamic model in this thesis provides novel insights into the transmission of motor signals from the basal ganglia to motor thalamus by suggesting new functional roles for active decorrelation and sensory responses in the basal ganglia, as well as cortical excitation of motor thalamus. Moreover, the simulation results of the Stop-signal task support the idea that the basal ganglia suppress movement in two steps: STN delays movement and then GPe Arky cancels movement.

  • Public defence: 2019-04-03 13:00 E2, Stockholm
    Francart, Nicolas
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Buildings in municipal climate change mitigation strategies: towards life cycle thinking2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fulfilling climate targets requires ambitious changes. The building sector is a large contributor to emissions of greenhouse gases (GHG), but also offers opportunities for climate change impact reductions. This thesis aims at supporting strategic decisions to reach climate change mitigation targets in the building sector, based on knowledge about what factors contribute significantly to climate impact from buildings in a life cycle perspective and how practitioners can influence these factors. More specifically, a first point of investigation concerns what aspects play a key importance in buildings’ climate impact, and what climate change mitigation strategies for the building sector should focus on. A quantitative analysis of backcasting scenarios for 2050 was performed using a spreadsheet model to estimate GHG emissions for the building sector. The parameters were adjusted to ensure that a GHG emission quota was reached in every scenario. This provided an illustration of four very different ways the building sector could contribute to the fulfillment of a global climate change mitigation target. The results were used to discuss what aspects of buildings were particularly important for target fulfillment. These aspects include a low-carbon energy mix, a reduction of GHG emissions from construction materials and an optimized use of space. A second point of investigation concerns how municipalities can influence practices through the use of environmental requirements in construction, in particular requirements based on a life cycle approach. A survey of Swedish municipalities was used to assess their current practices and knowledge level regarding mitigating climate change impact from construction, as well as the influence of a municipality’s size on these practices. It was followed up by semi-structured interviews investigating barriers to the use of environmental requirements in construction. Barriers were identified regarding in-house skills, access to data, resources, ambiguities regarding the law and guidance from national authorities. A stepwise strategy was suggested to overcome these barriers and successfully implement environmental requirements. Therefore, the thesis as a whole provides insight on how municipalities could use environmental requirements in construction to influence current practices in the building sector, so that the changes needed to fulfill the 1.5℃ target are implemented.

  • Hettinga, Marins
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    The design of participatoryprocess on a municipalitylevel: is a research on the roles of the different actorsin a participatory process in area developmentand on the effects of the design with a casestudy in the municipality of Groningen, theNetherlands.2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • Hernebrant, Karl
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Analysis of a mathematical model in Python for geographical disaggregation of freight growth rates based on the pivot-point method2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of the tasks for the Swedish Transport Agency, Trafikverket, is to provide traffic forecasts. To do this, a number of different forecast models are used, where Samgods is a nationally estimated model, where the quality of the results gets more unstable the more disaggregated level you are looking at. For rail this is handled with a model called Bangods. However, in Bangods the difference in geographical growth within each commodity group is lost.

    This thesis examines whether it is possible to replace the national growth rates from Samgods with geographical disaggregated growth rates. The growth rates are calculated with a mathematical model based on the pivot point method (PPM). The model has been implemented in Python and is used to disaggregate the growth rates from Samgods to maintain the geographical growth. However, the data to the model comes from different systems and models that use different link formats. Therefore a link matching method is required that converts links from one system to another before using PPM.

    The growth rates from the PPM and the link matching-method has been modelled for twelve commodity groups, 8 or 1417 geographic regions and with or without a train division with four train types. The best result was to used 96 growth rates divided into twelve commodity groups and eight geographical regions.

  • Borgström, Sara
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering. Stockholms universitet, Stockholm Resilience Centre.
    Balancing diversity and connectivity in multi-level governance settings for urban transformative capacity2019In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209Article in journal (Refereed)
    Abstract [en]

    Transformation towards sustainable developmentis about findings new ways of thinking, organising and doingto navigate wicked challenges such as climate change andurbanisation. Such challenges call for new governancemodes that match the complexity of the systems to behandled, where multi-level governance and collaborativeapproaches have been suggested to contribute to suchtransformative capacity building. This in-depth, transdisciplinarystudy investigates how the multi-levelgovernance context in Stockholm, Sweden, influences thetransformative capacity from the perspective of localsustainability initiatives. It was found that even though thedecentralized governance of the Stockholm region hosts agreat potential in supporting city wide transformation, it ishampered by disconnect between actors, levels and sectorsand the short-term funding structure. The suggestedinterventions highlight the tension between enablingcollaborations, while safeguarding a high local diversity ofinitiatives and flexibility to ensure sustained space forinnovation and learning.

  • Sörbom, Johanna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Gasim, Alia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Solid Waste Management at Inhaca Island2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Solid Waste Management has become an issue of increasing global concern. As the population continues to grow and consumption patterns change municipal authorities are facing immense challenges to manage the increasing amounts of solid waste in a sustainable way. This report is composed by interviews, observations and literary studies and aims to map the Solid Waste Management system of Inhaca Island in Mozambique, in order to identify challenges and recommend for further actions of improvement.

    At Inhaca Island, waste is deposited on an open dumpsite or otherwise buried or burned around the house yards. The lack of financial means contributes to an improper waste management on the with challenges in areas such as collecting, disposal and treatment of waste. For Inhaca Island it is important to focus on improvements of the Solid Waste Management system that are not as dependent on the financial means of Maputo municipality, such as improvement in public awareness and informal waste-picking. These factors need to be addressed before establishing a technical system. Inadequate collection and handling of waste exposes the population to hazardous waste and endanger both public health and the environment. Therefore it is important to improve the waste management conditions on the island.

  • Hederén, Amanda
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Evaluating material efficiency assessment methods: An assessment of the adaptability to B2B products using Ericsson telecom network infrastructure product as a case study2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Unsustainable consumption patterns and material scarcity has been recognised as one of the challenges within the European Union. To change these patterns policy makers within EU are looking towards a transitioning into circular economy. Electronics and manufacturers of energy related products is found to be important actors in this transition, due to the unsustainable trends of consumption and the materials of important contained in electronics. Energy related products are regulated by the Eco design directive (Directive 2009/125/EC) containing implementing measures on energy efficacy. Today the directive is lacking methods for assessing material efficacy in energy related products. CEN/CENELEC was 2015 requested to develop standard methods on how to assess the material efficiency aspects; durability, ability to reuse, repair, upgrade, re-manufacturabiliy, recyclability and recoverability and use of recycled content and CRM content. This study sets out to assess the adaptability of the preliminary publications of the standards on to an Ericsson radio network product. The study is divided into two parts, part one assesses the general and product specific implementation of the selected standard documents. The first parts of this study are document analysis and seven interviews used to triangulate the general opinions on the standards. In part two the study sets out to test two of the methods found in the standard documents. The study found in the collection of recycling data and rates for a small radio network product, the product had a recyclability of XX% and a recoverability of XX% and a time for disassembly of XX seconds using the suggested method eDiM. The findings of this study suggest that these standardised methods are welcomed by the telecommunications equipment manufacturer but concerns on the amount of data required, future purpose and the reliability of the assessment methods still creates worries for the future.

  • Los, Karolina
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Evaluation of the IFAS system with Deammonification Process for Nitrogen Removal from Municipal Wastewater2018Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
  • Ersöz, Timur
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Sustainable Development in Swedish and Canadian Campus Plans2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The concept of sustainable development being integrated into strategic spatial plans has increased in recent years. University campus plans are examples of such spatial plans, and these form the focus of this study. Sustainable development is a contested concept that lacks clarity and specific guidelines, which has led to various interpretations of the concept around the world. Campus plans in the present are not perfect regarding the implementation of sustainable development on campus. Three Canadian and three Swedish campus plans have been evaluated through content analysis in order to determine the sustainable aspects that were brought up. Furthermore, neighborhood assessment and certification systems were used to identify the sustainability aspects needed in a community. The campus plans differ from each other with regard to the sustainability aspects included and how these were addressed. The campus plans include strategies on how to address the sustainability aspects. The results show different understandings of sustainable development in campuses in the two nations. The major differences between the campus plans were that the Swedish campus plans brought up ecological aspects such as green structure and climate adaptation which were lacking in the Canadian campus plans. The Canadian campus plans on the other hand focused more on the social and the economic dimensions of sustainable development. There were also differences between the campus plans within the same nation. The different strategies between the campus plans can be used to complement each other. The shared knowledge and experience between these plans can help to improve the interpretation of sustainable development in campus plans. We can learn from the pros and cons of the different campus plans in order to enhance and improve the strategies to achieve sustainability in future campuses. The criteria from neighborhood assessment tools also help with developing campus plans and improving strategies which enable sustainable development.

  • Seljeseth, Sandra
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    En feministisk översiktsplan: En analys av Stockholms jämställda stadsutveckling2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The objective of this thesis is to elucidate how feminism and equality is discussed in relation to strategic urban planning in Stockholm. The analysis will evaluate how equality is treated and discussed in Stockholm’s comprehensive plan and how it is generally discussed within planning in Stockholm. The thesis starts with presenting a background on sustainability and equality in Stockholm followed by a theoretical background on environmental justice and the concept of the right to the city in relation to equality. Further on a theoretical background on post structural feminist theories and the concepts norm critical thinking, subjectivity, intersectionality and a discussion about the implications of language on the discourse will be presented. In the next segment the methods used will be presented, which are Bacchi’s (2009) method to analyse a discourse, ‘What’s the problem represented to be? ́, and semi structural interviews with professionals in Stockholm. The next section is a presentation of the results from the analysis and interviews, which indicates that equality in strategic planning would improve by including feminist perspectives such as intersectionality and norm critic thinking to integrate more people in the objective of the city.

  • Soto Trujillo, Adriana Lucia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Assessing individual water and sanitation insecurity: A novel tool to track universal access, the case of Mukuru informal settlements in Nairobi.2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Securing universal, safe, inclusive and affordable water and sanitation services, as targeted by SDG 6, is a challenge for urban settings. Particularly in informal settlements of Mukuru, Nairobi, were its crowded population, insecure land tenure and location in areas prone to environmental hazards places their inhabitants at greater risk of water and sanitation insecurity. Policy and research approaches to measure water and sanitation insecurity lack of a standard tool to assess the multiple dimensions that account for inequalities at the individual level. This study aimed to assess individual water and sanitation insecurity at Mukuru SPA. A novel 21 item insecurity scale was developed addressing water and sanitation availability, accessibility, affordability, perceived water quality, inadequate sanitation and hygiene. Three segments of the Mukuru SPA were selected. Data was collected from 302 individuals through a household survey. Statistical analysis was performed with SAS University software to identify water and sanitation conditions in the area, measure levels of water and sanitation insecurity, examine associations of insecurity levels and socio-economic characteristics and test the validity of the tool. Results indicated that most residents used water sources and sanitation facilities considered improved by global monitoring standards. Nonetheless, more than 50% of the residents of two of the studied segments had higher levels of water and sanitation insecurity. Individuals that were females, belonged to the lowest income ranges or that resided in young female or young male (<18 years old) headed-household were found more vulnerable to water and sanitation insecurity. Significant correlations of water and sanitation insecurity with time spent collecting water and sanitation cost/day, as well as correlations with number of trips to collect water and water cost/day validated the use of the tool.

  • Theokritoff, Emily
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Linking science and policy for climate change adaptation: The case of Burkina Faso: A stocktaking of the integration of scientific information on climate change into national adaptation and development policies2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Africa, especially tropical West Africa, is increasingly affected by climate change making it one of the most vulnerable regions in the world. Developing countries, including Burkina Faso, are severely hit due to their high exposure to climate stress and low adaptive capacity. Adequate climate change adaptation policies and plans are therefore essential to increase their resilience. This master thesis research project focuses on the science-policy interface for climate change adaptation in Burkina Faso, more precisely on how scientific information on climate impacts and adaptation is produced and integrated into policy formulation at a national level. The document analysis and the interviews conducted with ministerial technical units, independent academics, research agencies, civil society organisations and technical and financial partners confirm that climate change is a major threat to Burkina Faso and its impacts are increasingly being felt across numerous sectors. The recently elaborated National Adaptation Plans (NAPs) prove that adaptation has gained importance on the political agenda. However, the scientific basis of these documents and other sectoral development policies remains weak. It was identified that this was mainly due to a lack of financial and human resources, gaps in existing data and difficult access to this data. In addition, there is a need for increased awareness on the issue of climate change across all levels, institutionalisation linking researchers and policy-makers, capacity building of the stakeholders and dissemination of scientific information with the support of knowledge brokers. Reinforcing this science-policy interface would allow Burkina Faso to anticipate the impacts of climate change and plan adaptation measures accordingly, ultimately reducing the risks its population is exposed to.

  • Rachmawati, Titi Sari Nurul
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Impact of Priority and Protected Areas on Deforestation in Brazilian Legal Amazon2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Legal Amazon, the Brazilian region where much of the global tropical forest is located, has suffered from rapid deforestation for decades, undermining the provision of ecosystem services and the conservation of biodiversity on local and global scales. In order to prevent deforestation, the Brazilian government has established priority and protected areas to ensure the preservation of high biodiversity areas and ecosystem services. This study analyses whether the establishment of priority and protected areas have an impact in preventing deforestation, thus promoting biodiversity and ecosystem services. Furthermore, this study also analyses the extent to which deforestation affects priority areas for biodiversity conservation. Deforestation datasets from 2001 to 2014 of the Legal Amazon was processed and analyzed. The total area and density of deforestation were compared across three categories of land: (1) protected priority areas, (2) unprotected priority areas, and (3) non-priority areas. Spatial methods of geoprocessing and the statistical method one-way ANOVA were used to analyse the deforestation trends. As a result, the deforestation density was found to be lowest inside protected areas than in unprotected areas and non-priority areas. This implied that land-use restrictions in protected areas had more impact compared to unprotected areas and non-priority areas. Furthermore, deforestation has been more intensive in regions of lower biodiversity importance. Despite this positive evaluation, substantial tracts of forest had been converted within regions of high biodiversity importance. Therefore, the regulation of priority and protected areas must be evaluated and improved in the future. 

  • An, Jihyun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Feminist Futures: Futures studies through the lens of feminist epistemologies2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study explores how futures studies could engage with critical feminist perspectives in an intrinsic manner and what feminist futures might mean. The study brings attention to the less discussed subject of epistemological basis in futures studies. Literature study and semi-structured interviews with practitioners and researchers working with feminist approaches in the fields related to futures development was deployed. I’ve analyzed Wendell Bell’s discussion on epistemological foundation of futures studies from feminist epistemological perspective, and have suggested the potential of feminist epistemology of situated knowledges and partial objectivity for futures studies. Based on the findings from the semi-structured interviews, an alternative feminist scenario set in Swedish society in the year of 2050 in the format of a fiction is presented with the aim to provide a detailed and situated narrative of political and daily lives in feminist futures. The feminist futures scenario should not be understood as the singular feminist future suggested for implementation. The intention is to demonstrate how the visionary dimensions of feminist studies could be articulated in various forms of futures studies, and to open up space for rich debates on envisioning feminist futures. 

  • Verlhac, Clément
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Temperature dependence study ofmaterials and nanostructures forinfrared emission2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • Persson, Milton
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Transient Dynamics and Core Tunneling in Vertical Spin-Vortex Pairs2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • JUBIEN, Guillaume
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Decoding Electrocorticography Signals by Deep Learning for Brain-Computer Interface2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Brain-Computer Interface (BCI) offers the opportunity to paralyzed patients to control their movements without any neuromuscular activity. Signal processing of neuronal activity enables to decode movement intentions. Ability for patient to control an effector is closely linked to this decoding performance. In this study, I tackle a recent way to decode neuronal activity: Deep learning. The study is based on public data extracted by Schalk et al. for BCI Competition IV. Electrocorticogram (ECoG) data from three epileptic patients were recorded. During the experiment setup, the team asked subjects to move their fingers and recorded finger movements thanks to a data glove. An artificial neural network (ANN) was built based on a common BCI feature extraction pipeline made of successive convolutional layers. This network firstly mimics a spatial filtering with a spatial reduction of sources. Then, it realizes a time-frequency analysis and performs a log power extraction of the band-pass filtered signals. The first investigation was on the optimization of the network. Then, the same architecture was used on each subject and the decoding performances were computed for a 6-class classification. I especially investigated the spatial and temporal filtering. Finally, a preliminary study was conducted on prediction of finger movement. This study demonstrated that deep learning could be an effective way to decode brain signal. For 6-class classification, results stressed similar performances as traditional decoding algorithm. As spatial or temporal weights after training are slightly described in the literature, we especially worked on interpretation of weights after training. The spatial weight study demonstrated that the network is able to select specific ECoG channels notified in the literature as the most informative. Moreover, the network is able to converge to the same spatial solution, independently to the initialization. Finally, a preliminary study was conducted on prediction of movement position and gives encouraging results.

  • Arumuganainar, Ganesh Prasanth
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Simulation of Lower Limb Muscle Activity During Inclined Slope Walking2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Robotic exoskeletons are designed to assist patients with motor dysfunctions. Recent researches focus on extending the robotic assistance to patient activities other than ground level walking. This study aims to analyse the lower limb muscle activity during inclined slope walking contrasting with that of ground level walking. Two different angles of inclination were chosen: 9 degrees and 18 degrees. 9 degrees inclined slope is the universal ramp size for wheelchairs. The hypothesis is that muscle activation, and ultimately metabolic cost, in inclined slope walking is different from that of ground level walking. Collected motion data and simulation in OpenSim prove that the difference in metabolic cost is because of increased activity of ankle dorsiflexors and hip extensors and reduced activity of knee extensors. Finally, muscle activities along with other criteria such as kinematic alignment and joint range of motion are summed up as biomechanical considerations for robotic exoskeleton design.

  • Radhakrishnan, Ganesh Balaji
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Simulation Of Lower Extremity Muscle Activation During Obstacle Clearance2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Exoskeletons can be helpful to patients who suffer from muscular dysfunctions. Recent studies focus on exoskeletons which can perform complex human movements. Further analysis is needed in the area of unusual movements like obstacle clearance to design an assistive device which can deliver effective aid to the intended patients in need. It is necessary to understand the behavior of lower limb muscles when they are subjected to complex physical activity. This study is aimed to analyze the activity of muscles in the lower body during obstacle clearance. Two different levels of obstacle have been maintained, analyzed and compared with a normal gait. The muscle groups taken for the study are quadriceps, hamstrings and plantar flexors. The primary hypothesis is that the quadriceps, Hamstrings, and dorsi flexors tend to have higher muscle activation while performing a complex physical task like stepping over an obstacle with the heights of 20 cms and 36 cms than a normal walking gait. The muscles from those three mentioned groups contribute more to the obstacle clearance compare to that of normal gait. Further research is recommended to expand knowledge about muscle activation.

  • Francart, Nicolas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Erlandsson, Martin
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials.
    Malmqvist, Tove
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Larsson, Mathias
    Florell, Josefin
    Requirements set by Swedish municipalities to promote construction with low climate change impact2019In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 208, p. 117-131Article in journal (Refereed)
    Abstract [en]

    This study investigates how Swedish municipalities work to reduce the climate change impact of building construction. It focuses on current practices related to promoting the use of sustainable construction materials and on barriers to environmental requirements in construction, in particular environmental performance requirements based on LCA procedures. Municipalities were surveyed about the existence of municipal policies dealing with environmental issues in construction, the knowledge level about these issues, and the measures and requirements used to promote materials with low climate change impact. The survey was followed by semi-structured interviews about current practices and barriers to environmental requirements in construction. Results show that large municipalities are more likely to have dedicated policies and implement more measures than their smaller counterparts. However, willingness to implement future measures and knowledge of sustainable construction do not vary significantly with municipality population. Efforts are often limited to procurement, municipal construction projects and discussions with stakeholders. When requirements are set, they are almost always based on prescribing a technical solution (e.g. use of timber) rather than assessing environmental performance (e.g. calculating greenhouse gases emissions with a LCA tool). Measures that municipalities can take as public authorities are restricted by the law, which remains ambiguous as to the legality of environmental performance requirements. Legal issues, limited knowledge and resources appear to be the main barriers to environmental performance requirements in construction. A strategy is proposed to o​v​e​r​

  • Public defence: 2019-03-08 14:00 F3, Stockholm
    Zhou, Yushan
    KTH, School of Electrical Engineering and Computer Science (EECS), Fusion Plasma Physics.
    Impact of Surface Structures onDeposition and Erosion in a Tokamak2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fusion is a potentially unlimited and environmentally friendly energy source for human society in the future. However, along the way towards the application of fusion energy there are still unresolved complications. Among them, deposition and erosion are two critical issues. Deposition of fuel and impurities brings potential long-term fuel retention which may generate safety issues and limit the economic efficiency of fusion devices. Moreover, the erosion of the vacuum vessel wall in a fusion device generates impurities which contaminate core plasma and can restrict the life time of plasma facing component. The work in this thesis focuses on deposition and erosion on tiles in the JET-ILW project, which consist of tungsten (or tungsten coating carbon fibre composited) in the divertor and beryllium in limiters.

    For the deposition issue, micro ion beam analysis (µ-IBA) was used for observing deuterium and beryllium distributions over tile surfaces. The surface topography was obtained from SEM, optical microscope and confocal laser scan microscope. Distribution maps from IBA were compared with surface topography. To explain experimental results, modelling of ion trajectories was applied on real and artificial surfaces. Micro IBA results show that deuterium and beryllium accumulated in depressed areas, e.g. pits, cracks or craters. Modelling implies that ion gyration, surface roughness and inclination of the magnetic field could to some extent explain this non-uniform distribution of deuterium and beryllium. The same kind of issue, although on different scale length, occurs also for penetration of impurities into artificial castellation grooves, also studied experimentally in the thesis.

    For the erosion issue, the thesis includes analysis of a limiter marker tile which is designed for observing material erosion in JET. A new method to acquire erosion data from such marker tiles is proposed, by combining micro IBA and SEM image.  This method could separate the influence on IBA from roughness, a problem in applying IBA on rough surface. Similar Technique is applied to improve the interpretation of IBA measurements of deep penetration of deuterium into layered surface structures.

  • Public defence: 2019-03-06 13:00 1440, Stockholm
    Koller, Marius
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Supporting Patients and Therapists in Virtual Reality Exposure Therapy2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

     This thesis explores challenges for the design of Virtual Reality Exposure Therapy (VRET) systems. Exposure therapy is the established method for treatment of anxiety disorders and is typically delivered in-vivo, i.e. exposure to phobic stimulus in real environments. Virtual reality (VR), instead, offers the potential to conduct exposure therapy at the clinic. This approach has several benefits in terms of efficiency, customization and control, amount of exposure, and as an transition phase to real situations. However, currently many systems are limited in scope and are designed for research purposes without informing the design from therapist's practices. 

    My research aims to contribute towards the understanding of current practices in exposure therapy and investigates challenges for the design of these systems for the two main user groups, patients and therapists. Three different focus areas have been prevalent. First, we have studied therapist in real sessions to inform the design and development of VRET-systems. Second, we have evaluated two different VRET implementations supporting therapists to interact with patients. Third, on the patient's side, we have studied presence on healthy participants focusing on the influence of virtual bodies and patient movement in VR.

    This thesis summarises and discusses these studies. Overall, the studies emphasize the complexity of exposure therapy and the need for individualized patient conditions. This poses multiple challenges for the design of VRET-systems such as, first, the systems must offer flexibility to the therapists to orchestrate individualized therapy. Second, the systems must enable rich therapists-patient interaction. Third, the complexity of individualization of scenarios and sessions must be addressed in the design of the therapist's interface. Fourth, for patients, body avatars influences presence differently depending on the scenario and locomotion is challenging as offices are typically small.

  • Andersson, Elin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Hietala, Sofia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Application of a new method to improve river cross sections derived from satellite images2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In hydrological and hydraulic modelling, river geometry is a crucial input data. Recent investigations have been looking at methods to improve the description of cross sections extracted by DEM derived by satellite images. SRTM derived DEM are often lacking precise information as the sensors cannot detect the submerged river parts, but, on the other hand, it is available on a global scale which makes it very attractive and useful, especially in data scarce regions. This study aims at applying the so called “slope break” method to improve river cross section geometry extracted from SRTM DEM. The report is divided into three parts: a) The making of a Matlab-code to improve cross sections geometry extracted by satellite derived DEM; b) an application of the code to real cross-sections from the river Po in Italy and c) hydraulic simulations with and without SRTM modified cross sections to test the performance of the method, in collaboration with senior colleagues. The Matlab successfully performs the slope break point and finds, when appropriate, the approximated lowest point zmin of the cross section below the water surface. The comparison of the river geometry of the modified SRTM cross sections versus LiDAR available cross sections show the good performance of the method in improving the river geometry description. This code can simplify the work and improve many SRTM river cross sections in an effective way. The hydraulic simulations performed with and without the modified cross sections show how the modified SRTM model improves when compared to LiDAR results 

  • Corsini, Filippo
    et al.
    stituto di Management, Scuola Superiore Sant’Anna, 56127 Pisa, Italy.
    Laurenti, Rafael
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Meinherz, Franziska
    Laboratory for Human-Environment Relations in Urban Systems, Ecole Polytechnique Fédérale de Lausanne EPFL, Station 2, CH-1015 Lausanne, Switzerland.
    Appio, Francesco Paolo
    Research Center, Léonard de Vinci Pôle Universitaire, 92916 Paris La Défense, France.
    Mora, Luca
    The Business School, Edinburgh Napier University, Edinburgh EH14 1DJ, UK.
    The Advent of Practice Theories in Research on Sustainable Consumption: Past, Current and Future Directions of the Field2019In: Sustainability, ISSN 2071-1050, Vol. 11, no 2Article in journal (Refereed)
    Abstract [en]

    The application of practice theories in the domain of sustainability research in consumer studies is increasingly advocated based on the premise that this allows to analyse consumption as a social phenomenon. Consequently, the applications of social practice theories to this field are expanding geometrically and to date, little retrospective work on this evolution has been made. We conduct a bibliometric analysis of applications of practice theories in the domain of sustainability research in consumer studies. Our results show a temporal succession of research trends: ‘consumer identity’ dominated the field between 2009 and 2012, ‘business and governance’ between 2012 and 2014, ‘sustainable consumption and production’ between 2013 and 2014, ‘urban living and policy’ between 2014 and 2015 and ‘household energy’ from 2015 until the present. We see a high potential of future applications of practice theories in the fields of the sharing and circular economy, as well as in research on smart cities. We provide new insights into the evolution and future trends of applications of social practice theory to domains that are relevant for research on sustainability and consumer studies

  • Public defence: 2019-03-08 10:15 F3, Stockholm
    Owrang, Arash
    KTH, School of Electrical Engineering and Computer Science (EECS).
    In Pursuit of Ideal Model Selection for High-Dimensional Linear Regression2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The fundamental importance of model specification has motivated researchers to study different aspects of this problem. One of which is the task of model selection from the set of available competing models. In this regard, several successful model selection criteria have been developed for the classical setting in which the number of measurements is much larger than the parameter space. However, when the number of measurements is comparable with the size of the dimension of the parameter space, these criteria are too liberal and prone to overfitting.

    In this thesis, we consider the problem of model selection for the high-dimensional setting in which the number of measurements is much smaller than the dimension of the parameter space. Inspired by previous work in this area, we propose a new model selection criterion based on the Fisher information. We analyze the performance of our criterion as the number of measurements increases to infinity as well as when the noise variance decreases to zero. We prove that the proposed criterion is consistent in selecting the true model in both scenarios. Besides, we conceive a computationally affordable algorithm to execute our model selection criterion. This algorithm utilizes the solution path of Lasso to narrow the set of all plausible combinatorial models down to a few ones. Interestingly, this algorithm also can be used for choosing the regularization parameter in the Lasso estimator properly. The empirical results support our theoretical findings. We also practice the task of model selection in situations where there are multiple measurement vectors available. Here, we also allow the elements of the noise vector to be spatially correlated. For such situations, we propose a non-negative Lasso estimator that is inspired by covariance matching techniques. Here, to tune the corresponding regularization parameter, we use our model selection criterion that has been introduced earlier. Empirical results show that our non-negative Lasso estimator can correctly select the true model when a relatively small number of measurement vectors are available. Moreover, the empirical results show that our proposed method is rather insensitive to a high correlation between the columns of the design matrix. In the last part of the thesis, we apply some of the theories and tools developed for model selection in the previous chapters to the problem of change point detection for noisy piecewise constant signals. In more details, we first consider the previously proposed change point estimation method, fused Lasso, and explain why it cannot guarantee the detection of the true change points. Then, we propose a normalized version of fused Lasso that is obtained by normalizing the columns of the sensing matrix of the Lasso equivalent. We analyze the performance of the proposed method, and in particular, we show that it is consistent in detecting change points as the noise variance tends to zero. Finally, we show numerical experiments that support our theoretical findings.

  • Frank, Isabella
    KTH, School of Electrical Engineering and Computer Science (EECS).
    “Less Is More, Forget The Mass”: An Explorative Study on Product Transformation Strategies for Subscription-first Newspapers2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The competitive market of the newspaper industry has undergone considerable changes driven by new technology, the internet and changing audience behavior. The industry is facing two current crises, the decline in print and advertising revenues, and at the same time, the growth of free online content. One of the major challenges for traditional newspapers is to find new ways to increase digital revenues to make-up for these losses. This study uses qualitative interviews and readership data collected from a large traditional publisher to explore how the newspaper can reshape the customer value proposition and increase digital subscriptions. Additionally, the study uses case examples from the industry to combine theoretical reflections with practical development. The newspapers need to continue to explore new opportunities in media, and balance focus between traditional and newer, more radical activities. In the future, success will be dependent on the integration of value-added elements. The findings suggest that traditional newspapers should enhance the value proposition by investing even more in high-quality and multimedia journalism. The audience is willing to pay if the product has a high relative value and is differentiated from the free online news. This can be done by an extensive integration of technology into the journalistic processes and a more defined product. Further, the publisher needs to abandon mass media models and offerings that provide something for everyone, instead offering niches and limited-edition news products to add new revenue streams.

  • Eriksson, Urban
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Dynamic Path Planning for Autonomous Unmanned Aerial Vehicles2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis project investigates a method for performing dynamic path planning in three dimensions, targeting the application of autonomous unmanned aerial vehicles (UAVs).  Three different path planning algorithms are evaluated, based on the framework of rapidly-exploring random trees (RRTs): the original RRT, RRT*, and a proposed variant called RRT-u, which differs from the two other algorithms by considering dynamic constraints and using piecewise constant accelerations for edges in the planning tree. The path planning is furthermore applied for unexplored environments. In order to select a path when there are unexplored parts between the vehicle and the goal, it is proposed to test paths to the goal location from every vertex in the planning graph to get a preliminary estimate of the total cost for each partial path in the planning tree. The path with the lowest cost given the available information can thus be selected, even though it partly goes through unknown space. For cases when no preliminary paths can be obtained due to obstacles, dynamic resizing of the sampling region is implemented increasing the region from which new nodes are sampled. This method using each of the three different algorithms variants, RRT, RRT*, and RRT-u, is tested for performance and the three variants are compared against each other using several test cases in a realistic simulation environment.  Keywords

  • Norgren, Eric
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Pulse Repetition Interval Modulation Classification using Machine Learning2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Radar signals are used for estimating location, speed and direction of an object. Some radars emit pulses, while others emit a continuous wave. Both types of radars emit signals according to some pattern; a pulse radar, for example, emits pulses with a specific time interval between pulses. This time interval may either be stable, change linearly, or follow some other pattern. The interval between two emitted pulses is often referred to as the pulse repetition interval (PRI), and the pattern that defines the PRI is often referred to as the modulation.

    Classifying which PRI modulation is used in a radar signal is a crucial component for the task of identifying who is emitting the signal. Incorrectly classifying the used modulation can lead to an incorrect guess of the identity of the agent emitting the signal, and can as a consequence be fatal.

    This work investigates how a long short-term memory (LSTM) neural network performs compared to a state of the art feature extraction neural network (FE-MLP) approach for the task of classifying PRI modulation. The results indicate that the proposed LSTM model performs consistently better than the FE-MLP approach across all tested noise levels. The downside of the proposed LSTM model is that it is significantly more complex than the FE-MLP approach.

    Future work could investigate if the LSTM model is too complex to use in a real world setting where computing power may be limited. Additionally, the LSTM model can, in a trivial manner, be modified to support more modulations than those tested in this work. Hence, future work could also evaluate how the proposed LSTM model performs when support for more modulations is added.

  • Lewenhaupt, Axel
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Real Time Depth Sorting of Transparent Fragments2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Using transparency is an important technique for modelling partial coverage in computer graphics and is used for a variety of effects such as hair, fur, glass, smoke and particle effects. Replacing the per object sorting as the dominant algorithm used in real time 3D engines with anew algorithm with less rendering artifacts could let artists use more transparency and effects in their scenes.

    This thesis evaluates two algorithms as a possible replacement to the per object sorting algorithm, the per pixel linked list and the weighted blended order-independent transparency (WBOIT) in a visual comparison and a performance evaluation.

    The results shows that neither of the algorithms are suitable as replacement as a unified and general transparency algorithm but there are cases where the algorithms can be used as a replacement. The per pixel linked list has good visual quality but lacks in performance and can be used in limited scope such as hair renderings. The WBOIT algorithm has good performance but the approximation used can give noticeable errors in color when there is a large difference in depth between transparent objects.

  • Song, Shiping
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, perception and learning, RPL.
    Study of Semi-supervised Deep Learning Methods on Human Activity Recognition Tasks2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project focuses on semi-supervised human activity recognition (HAR) tasks, in which the inputs are partly labeled time series data acquired from sensors such as accelerometer data, and the outputs are predefined human activities. Most state-of-the-art existing work in HAR area is supervised now, which relies on fully labeled datasets. Since the cost to label the collective instances increases fast with the increasing scale of data, semi-supervised methods are now widely required.

    This report proposed two semi-supervised methods and then investigated how well they perform on a partly labeled dataset, comparing to the state-of-the-art supervised method. One of these methods is designed based on the state-of-the-art supervised method, Deep-ConvLSTM, together with the semi-supervised learning concepts, self-training. Another one is modified based on a semi-supervised deep learning method, LSTM initialized by seq2seq autoencoder, which is firstly introduced for natural language processing. According to the experiments on a published dataset (Opportunity Activity Recognition dataset), both of these semi-supervised methods have better performance than the state-of-the-art supervised methods.

  • Jonsson, Jacob
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Cooperative versus Adversarial Learning: Generating Political Text2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis aims to evaluate the current state of the art for unconditional text generation and compare established models with novel approaches in the task of generating texts, after being trained on texts written by political parties from the Swedish Riksdag. First, the progression of language modeling from n-gram models and statistical models to neural network models is presented. This is followed by theoretical arguments for the development of adversarial training methods,where a generator neural network tries to fool a discriminator network, trained to distinguish between real and generated sentences. One of the methods in the research frontier diverges from the adversarial idea and instead uses cooperative training, where a mediator network is trained instead of a discriminator. The mediator is then used to estimate a symmetric divergence measure between the true distribution and the generator’s distribution, which is to be minimized in training. A set of experiments evaluates the performance of cooperative training and adversarial training, and finds that they both have advantages and disadvantages. In the experiments, the adversarial training increases the quality of generated texts, while the cooperative training increases the diversity. The findings are in line with the theoretical expectation.

  • Schulze, Filip
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Predicting website exits with machine learning2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Website hosts want interested visitors who engage in the activities that are the purpose of a website. This is usually achieved by designing the website to be simple to navigate and aesthetically pleasing. As the design is done before the visits, it would be an exciting addition if the website could identify the visitors who become disinterested during their visits, and then offer personalized motivation for the visitor to engage in the website.

    This study aims to identify whether a visitor is about to leave a website, by using machine learning models to predict their exits. The purpose of that is to offer personalized motivation in real time for visitors to continue their visits. That is however outside the scope of this study. This research investigates how well machine learning models can predict website exits from session data.

    The algorithms chosen for the prediction are an Artificial Neural Network (ANN) and a Support Vector Machine (SVM). These are trained on session data. An important part of the research is to extract suitable features from the session data to enhance the prediction. The models are cross-validated and it is found that the models show success in predicting exits, and that it is possible to predict exits with a performance of at least 0.70 Area Under the Curve (AUC).

  • Deng, Jie
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Training Multi-Agent Collaboration using Deep Reinforcement Learning in Game Environment2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Deep Reinforcement Learning (DRL) is a new research area, which integrates deep neural networks into reinforcement learning algorithms. It is revolutionizing the field of AI with high performance in the traditional challenges, such as natural language processing, computer vision etc. The current deep reinforcement learning algorithms enable an end to end learning that utilizes deep neural networks to produce effective actions in complex environments from high dimensional sensory observations, such as raw images. The applications of deep reinforcement learning algorithms are remarkable. For example, the performance of trained agent playing Atari video games is comparable, or even superior to a human player.

    Current studies mostly focus on training single agent and its interaction with dynamic environments. However, in order to cope with complex real-world scenarios, it is necessary to look into multiple interacting agents and their collaborations on certain tasks. This thesis studies the state-of-the-art deep reinforcement learning algorithms and techniques. Through the experiments conducted in several 2D and 3D game scenarios, we investigate how DRL models can be adapted to train multiple agents cooperating with one another, by communications and physical navigations, and achieving their individual goals on complex tasks.

  • Bouvin, Sofia
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Mattsson, Patrik
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Språkdidaktiska metoder i programmeringsundervisning: En undersökning av möjligheten att anpassa språkdidaktik till programmeringsundervisningen i den svenska gymnasieskolan2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    From 2018, programming courses will be made available for all students in upper secondary school (Sweden). This highlights the need for working and well-defined teaching methods that are adapted for students with different background and experiences in technology. Programming is a formal language unlike Swedish or English that are natural languages. Research shows that when we interpret programming code, the language center of our brain is more active in comparison with regions of the brain that are more connected with logical and mathematical thinking. In this report we investigate the relationship between formal and natural languages in order to evaluate the extent to which language leaching methods can be applied to programming education. To get an overview of how programming education is currently structured, we conducted interviews which were then analyzed from a qualitative perspective. These interviews make it possible to understand the conditions of learning situations in computer education, and what the main difficulties in today's programming classroom are. The scope of this study is limited to introductory programming, more specifically in the Swedish upper secondary school. The result shows that the biggest difficulty for students in introductory programming, is to program without syntax becoming too much of a time-consuming struggle. In addition, the interviews show that teachers in programming courses have little research-based methods to use in their teaching in order to address these difficulties. In our study we find that only a subset of the syllabus of introductory programming can be dealt with using language teaching methods. To increase students' understanding of programming language syntax, the student should be exposed to many examples of programming code. Through these code examples the students are enabled to process the programming language in order to extract the syntax rules of the current language. An obvious step in this process consists of the students' memorizing these lines of code. This way the students' syntax error rate can be reduced.

    An additional challenge when teaching in introductory programming is the confusion of concepts that can occur in a conflict between the Swedish and English languages. It is therefore important to allow the students to reflect upon the semantic meaning of keywords, concepts and commands in a programming language. Through reading of code examples, the students can also get a feeling of how programming code is best structured and commented in order to aid readability. With our proposed approach to teaching programming, we want to inspire to new ways of thinking about programming education, but we also want to leave a bit of space for practice and further research for those interested in the world of programming and computer education.

  • Lundell, Bertil
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Ämnesövergripande arbetssätt –ur ett lärarperspektiv igymnasieskolan: En empiristyrd tematisk analysstudie2019Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Interdisciplinary working methods has both a long history and generate good results and yet it has a relatively hidden position within the educational system. How come, is it too difficult? Or are there other reasons? This is the objective for this study.This study will describe the experiences teachers, in the upper secondary school, express while working within interdisciplinary working methods. The study has been performed by a number of interviews and analyzed with applied thematic analysis framework. The result of the study shows that the themes the interviewees describe are; the subjects and combinations of those, ways of working, the students, the colleagues, the results and the prerequisites. The collaboration between the teachers is not a walk in the park, however the lack of time to perform planning and coordination are the major obstacles preventing successful interdisciplinary working methods.The importance of the enthusiasts is another result of the study. One conclusion is that the informants do not naturally thought about their own teaching of several subjects as a cross-disciplinary approach. The most common form of interdisciplinary working method is the project form. Another conclusion is that: when the follow-up is done, it is the work method that is evaluated and not the students' knowledge.

  • Xia, Ziqi
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Mani Alvandian, Sohrab
    KTH, School of Electrical Engineering and Computer Science (EECS).
    3D Visualized Indoor Positioning System2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Three-dimensional visualization refers to the process by which graphical content is created using the Three-dimensional software. While working with Threedimensional visualization, different indoor positioning techniques can be used to detect and track the movement of objects. Combining these two technologies provide the ability to monitor a room and its objects in real time. Positioning is the process of recording the movement of objects or people. Positioning techniques can be used in many different areas such as emergent situations and tracking objects with potential risks as an aid. It is not self-evident how well this kind of a system would work in the given contexts. To address this, the method has consisted of a literature study focused on existing theories of positioning and different factors that affect the positioning outcome and a case study on positioning systems in a number of existing indoor positioning systems. The purpose of this project is to present and evaluate a prototype where an indoor positioning system will be combined with a specific platform which works with simple types of hardware signals to generate three-dimensional models. The goal is to present a system that will have the ability to be used without any infrastructure or external hardware. Different indoor positioning systems will be analyzed as well as their use in various scenarios. This thesis evaluates various technical choices, and provides an overview of some of the existing wireless indoor positioning solutions and the theory and methods used, before describing the case study, including the development process, problems faced, the result, and the experimental testing results. In conclusion, the thesis presents a prototype which is validated to fulfill the basic expectation of a three-dimensional visualized indoor positioning system.

  • Rodopoulou, Viktoria
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    COsavings of selling food surplus in plastic trays compared to incineration and anaerobic digestion in Sweden.: With an application at KTH Royal Institute of Technology2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Food waste has become a global environmental concern in recent years with food waste prevention being the optimal solution. In Sweden, initiatives to reduce food waste, focus on re-using methods like selling or donating food. The purpose of this study is to analyze the environmental savings, in terms of CO2 eq. savings, of re-using food compared to incineration and anaerobic digestion in Sweden. The study aims to map out the processes of the food waste management system and investigate the parameters that effect the performance of each method using Life Cycle Assessment (LCA). The research is conducted by using a case study, “Save food at KTH” which is an initiative at KTH Royal Institute of Technology in Sweden, to reduce food waste through a mobile application for sharing information on the available edible food waste around campus and options to purchase it through the app.

     

    The results showed that re-using food waste has more CO2 savings compared to the other two energy recovery methods. Avoided emissions from food production when food waste is sold, were the most important factors that framed this result. However, the types of foods are also critical on the choice of food waste management method when the focus is on the CO2 emissions of the system. Foods with high water content or plant-based protein sources can be energy efficient in anaerobic digestion processes as well. In this case, selling food waste can be used as a complementary method.

  • Ravan, Nazila
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    A Study on Life Cycle Assessment-based Tool for the Early Stage of Building Design2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The responsibility of the building sector to diminish the harmful environmental impacts, locally and globally, has been extensively considered. Thus, Environmental Impact Assessment (EIA) in building and construction practices has been widely implemented. Among several available EIA methods, Life Cycle Assessment (LCA) is the only standardized method which provides a holistic overview of environmental impacts to support the decision-making process. However, there are several barriers that hinder the process of implementing the LCA-based tools in the building sector. Specifically, the demand for a simplified LCA-based tool adapted to the early stage of the building design is rather high. Recently, the Construction Sector's Environmental Calculation Tool (Byggsektorns Miljöberäkningsverktyg BM v1.0) is developed to assist non-experts without knowledge of LCA. Architects, as one of the main target groups of the BM tool, have limited knowledge about the LCA approach due to its complexities; further, the architects have their own requirements for applying an LCA-based tool towards leveraging in the early design process. Hence, it leads to scepticism whether the BM tool has been so far successful to entice the architects' attention towards employing the BM tool in that process.

    This master thesis aimed to investigate if the newly-developed LCA-based tool, namely the BM tool, is a desirable choice for architects to evaluate the environmental impacts of their design at the early stage of building design. To be able to perceive more deeply the BM tool, as an environmental assessment and a decision support tool for architects, two main procedures, i.e., quantitatively and qualitatively, were employed to cover different technical and functional angles of the tool: (i) an LCA-based carbon footprint assessment for two reference buildings along with comparing the achieved results with the simplified Environmental Load Profile (ELP-s) tool, plus (ii) using a framework included various criteria for LCA- based tools in the early stage of building design.

    The findings from the quantitative analysis were consistent so that the concrete frame building produces a greater amount of carbon footprint during the stages A1 to A4 compared to the wooden frame building. The considerable deviation was related to the carbon footprint of aluminium profile in the material production stage. This could be due to the fact that in the BM database it is not specified whether aluminium profile was recycled or not. Regarding the carbon footprint in material transport stage, the inconsistent results were mostly linked to the default values in the BM database in which values for two of the main parameters (distance and mode of transport) differed. Particularly, the absence of boat as a transport mode and an error related to an unneeded distance value for concrete transport were identified in the BM database. The framework, used to evaluate the desirability of the BM tool for architects, suggests several criteria required for an LCA-based tool implementation in the early design. The outcome indicated that the majority of criteria, not satisfied by the BM tool, were related to the geometry parameter and associated 3D model. Thus, in order to make the decision-making process, desirable for architects in the early stage of building design, the two parameters, i.e., material and geometry, should be utilized in parallel.

    On the one hand, the LCA methodology in the BM tool is simplified in a way that makes the process comprehensible and easy to learn for non-LCA-experts. Since the tool is under the development, minor amendments would make the carbon footprint evaluation robust for the early stage of design. On the other hand, from the requirements of the architects' point of view, the fundamental modifications are needed in the structure of the tool. If architects intend to work with such an LCA-based tool, they have to make an extra effort to translate the resulted information from the environmental assessment tool to the inputs of the modelling tool and vice versa. This leads to an undesirable and inefficient design process for architects.

  • Torstensson, Johanna
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Investigation of Inconcistencies in Climate Policy Engagement amongst Major Corportations2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report investigates inconsistencies in climate policy engagement of 16 major corporations in five industrial sectors and analyses which problem areas are significant in the inconsistency of their engagement. The purpose of this report was to scope the area of inconsistent climate policy engagement on behalf of the company GES International – Global Engagement Services, who offers advisory services in responsible investment. This report has been performed through a literature review and is partly based on a report on corporate carbon policy footprint by the independent organisation InfluenceMap.

     

    All companies investigated in this report are to some extent supporting the climate agenda of the Paris Agreement, including limiting global warming to below two degrees. Nevertheless, 14 of the 16 companies are at the same time showing a negative climate policy engagement. The problem areas leading up to this inconsistency that have been detected in this report are; when companies are taking part in organisational relationships that are unsupportive of climate change mitigation strategies, when companies are against climate legislation, the unwillingness of companies to change their own industrial sector and companies showing mixed signals on the same policy topic.

     

    The conclusions that can be drawn from this report is that there are substantial inconsistencies in the climate policy engagement of companies and it can be difficult to assess what the company’s true stance on climate engagement is. Some measures to improve on consistency is for companies to review their policy engagement and be transparent on what their actual stance climate engagement is, however this transition can take time.  

  • Rydström, Henning
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematical Statistics.
    A study and further development of nonlinear unsupervised methods: With applications to financial data2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The main focus for this thesis is nonlinear dimensionality reduction. When analysing data of high dimension it is often vital to find a lower dimension representation of the data, while preserving as much information as possible. Dimension reduction is therefore used in many fields of science and in many industries.

    This thesis will deal with applications in finance, and hence financial data. The thesis was made in collaboration with the third national Swedish pension fund, AP3. They wanted a dimension reduction method that is efficient, noise robust and which preserves both linear and nonlinear patterns in the data. Consequently, the main purpose of this thesis is to develop such a method. The method proposed by this thesis is a combination of published and self-developed extensions of the Isomap method.

    For investigating different methods they are applied on both academic data sets in three dimensions, such as the Swiss-roll and the S-plane, and on specific financial data sets such as the S\&P 500 and commodity prices. The results from the academic examples indicate that the proposed method manages to find nonlinear structures in noisy data in an efficient way. The results from the financial data sets are interesting but much harder to interpret. AP3s idea is to use our proposed method as a pre-processing step in their big data algorithms for trading and economic analysis, but that application is out of scope for this thesis.

    The last part of the thesis will make a brief introduction to Topological data analysis (TDA). It will cover the basic theory and will be used for some simple applications on financial data.

  • Nyman, Daniel
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematics (Div.).
    A Study of Isomap Extensions and Topological Data Analysis with Applications to Financial Data2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis focuses mainly on nonlinear dimensionality reduction. A comparison of a number of different extensions of the Isomap-algorithm found in the literature is presented as well as an introduction to the underlying theory. Further, two novel extensions of the algorithm are introduced. Residual variance is used as a means of quantifying performance and optimizing parameters. One of the novel approaches, NNL-Isomap, is applied to financial data sets such as the S&P 500, the results are compared with those from PCA and, when appropriate, well-known academic models. The thesis further introduces a selection of concepts from topological data analysis together with corresponding short explanatory examples as well as applies these concepts to some simple financial examples.

  • Nunes da Silva Ramos, Filipe José
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Identification of Suitable Areas for Offshore Macroalgae Cultivation2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Research in sustainable macroalgae aquaculture has been gaining hype (e.g. Seafarm) to provide advancements in new significant sources of food, feed, materials and bio-energy. Despite the fact that in Asia the offshore production of macroalgae is established for many decades, in Europe is still in its infancy. The issue on where to find suitable cultivation areas without conflicting with current uses to respect the environment and the socio-economic activities is a great challenge. This Master of Science thesis aimed to find suitable offshore areas in order to facilitate implementations of macroalgae cultivations in the Swedish West Coast. Thirteen criteria in environmental, economic and social sustainability aspects were identified and employed (e.g. Depth, Distance to Ports, and Natural and Preserved areas (NPAs)), and the tools Geographic Information Systems (GIS) and Multi-criteria Analysis (MCA) were used in the form of GIS-MCDA, an integrated method available in Idrisi. To aggregate the criteria, Boolean and Weighted Linear Combination (WLC) techniques were applied. The results showed that Boolean areas cover 537 km2 (6,98% of the study area). The best suitable areas, possessing the maximum suitability index 10, that resulted from two WLC models comprise 5 km2 (0,07% of the study area) and 26 km2 (0,34% of the study area) including and excluding the criterion NPAs as constraint, respectively. The results further indicated that GIS-MCDA models excelled in providing an overview for effective spatial decision-making. Both techniques play a role in suitability analysis and complement each other in finding an optimal site which could be carefully selected out of the identified areas. It is recommended that areas with a suitability index 10 be chosen inside Boolean suitable areas. Moreover, this study could act as a driving force to build a resilient planning framework that would boost sustainable placement and development of offshore macroalgae cultivations.