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• Public defence: 2020-01-31 14:00 K1, Stockholm
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Chemical Engineering.
Water density impact on water flow and mass transport in rock fractures2020Doctoral thesis, comprehensive summary (Other academic)

One way of taking care of spent nuclear fuel is to place it in a geological repository. In Sweden, a three-barrier system is planned. The system is based on encapsulating the fuel in copper canisters. These are surrounded by bentonite clay and buried under 500 m of bedrock. As a part of the safety assessment, the Q-equivalent model is used to quantify the possible release of radioactive material. This model also describes the rate at which corrosive agents carried by seeping water in rock fractures can reach the canisters, which may affect the longevity of the canisters.

The aim of this thesis was originally to develop an experimental, phys- ical model to visualize and validate the Q-equivalent model. However, the overarching theme of this work has been to study the effect of minor density differences that might be overlooked in experiments, both concentration- dependent and density-difference induced by light absorption.

In the initial diffusion and flow-experiment and associated calculations and simulations, it was found that simple Q-equivalent can describe and quantify the mass transport in both parallel and variable aperture fractures. However, this is the case only if the density difference between seeping water and clay pore water is insignificant. It was found in experiments with dyes used to visualise the flow and diffusion patterns that even minimal density differences could significantly alter the flow pattern. Density differences can result from concentration gradients or be induced by light absorption. TheQ-equivalent model was extended to account for density-induced flow. The importance of density-induced flow due to concentration gradients at the setting of a long-term repository for nuclear waste was evaluated. It was found that concentration gradients are able to induce rapid vertical up- or downward flow. This could increase the overall mass transport of radioactive material up to the biosphere or carry it downward to larger depths.

• KTH, School of Industrial Engineering and Management (ITM), Learning.
Varierande hinder och svårfångade möjligheter för språkintroduktionselever: En vansklig resa i tiden2019Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis

This qualitative study covers the subject of mathematics. The methods used are student interviews, meetings and discussions with teachers as well as review of mathematical test scores and a broad, inductive, thematic analysis of the interview data.It describes students’ perceptions of obstacles and opportunities in their schooling in mathematics prior to arriving in Sweden and in their Swedish second language introductory program. The results also provide the students’ views on their possibilities to pass in mathematics. A discussion concludes critical progress factors that need to be addressed in order for the students to have realistic possibilities to pass in mathematics.Swedish, as a new academic language for the students, is one of the biggest challenges in their mathematics education. The study describes similarities, but most of all differences between their schooling before and after arrival in Sweden. Among those are differences between authoritarian and authoritative styles of education and communication as well as differences in socio-culturally based behaviours of which the latter can generate huge learning obstacles if not addressed. Some students have manged to adopt effective working methods while others show a need for bonding, support and assistance to cope in the Swedish school characterized by freedom with responsibility.In 2017, the Swedish school inspection authority conducted a quality inspection of 42 schools engaged in second language introduction programmes (Skolinspektionen, 2017). The outcome revealed shortcomings, i.e. the possibilities for students to reach their goals in those programs varied significantly. The critical progress factors of this study address some of the shortcomings highlighted in the quality inspection, thus emphasizing the relevance of this study.

• KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
Medborgardialogens makt och vanmakt: Fallstudie av Rosens röda matta sex år efter invigning2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

• KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
The Organic Pattern of Space:: A Space Syntax Analysis of Natural Streets and Street Segments for Measuring Crime and Traffic Accidents2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

The natural streets model is a research prototype that has been shown to perform better than the conventional GIS-based streets segments for explaining traffic flow and human movement. However, given its experimental status, a gap in the literature was identified. Therefore, the aim of this thesis was to contribute to the literature by investigating the wider applications of natural streets and observe whether a city’s spatial configuration (or structure) is related to outcomes of human behaviour and activity. In this case, the two previously unstudied outcomes were chosen: crime and traffic accidents. Taking an exploratory approach, Stockholm was chosen as the case study. Using the space syntax methodology, the street segments and natural streets connectivity was used to analyse whether accessibility or ‘potential through movement’ is associated with crime and traffic accidents. Two study areas were generated: a primary study area consisting of six nested zones and a secondary study area with hot spots and cold spots for events of crime and traffic accidents. To observe the statistical association between connectivity and events of crime and traffic accidents for natural streets and street segments, a classical regression model was used. The regression analysis showed that natural streets perform significantly better than street segments as they are better able to explain events of crime and traffic accidents. However, more so for traffic accidents. Most importantly, the topological structure or scaling characteristics of natural streets served as a better indicator for measuring human phenomena. The implication of this is that it could potentially be used to further the understanding of human activities in the context of the urban environment.

• KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
Retrofitting Accessibility in a Rapidly Expanding City: The Case of Bus Rapid Transit and Transit-Oriented Development in Dar es Salaam2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Urbanisation is a global trend, but in recent decades it has been occurring at particularly high rates in the Global South. Cities in Sub-Saharan Africa are facing a number of challenges as their populations grow, and among these, urban accessibility stands out as one of the most difficult to contend with. Meeting this challenge will require new solutions, and recently Bus Rapid Transit (BRT) and Transit-Oriented Development (TOD) have emerged as two potentially revolutionary innovations, especially when combined. In 2016, Dar es Salaam launched a BRT system, and in 2017 it introduced a TOD strategy in order to combat the city’s urban accessibility crisis. This study investigates the urban form at and around BRT stations in order to characterise BRT-TOD in the city and extract lessons for future implementations of BRT-TOD in Dar es Salaam and beyond. The investigation was carried out within the framework of urban morphology. It was found that at locations in the city centre, BRT has generally been able to integrate seamlessly into the built environment and achieve many of the core principles of TOD. In the rest of the city, however, BRT acts simply as a form of transit, with stations generally removed from the urban fabric and the local place. Some general issues are the large building setback, the number of informal vendors, private transport operators, exclusive new developments, lack of public spaces, the low quality of the pedestrian environment and the reinforcement of unsustainable forms of urban sprawl. This study aims to contribute to a growing discussion of sustainable urban accessibility solutions in the rapidly expanding cities of the Global South.

• KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
Tensions and Synergies Between Tactical Urbanism and Social Sustainability: A Case Study of the Sunset Triangle Plaza2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

For the past several years, the term social sustainability has gained a strong foothold within urban studies and has become a pervasive and trendy term that seems to be on everyone’s lips. Public space is widely acknowledged as an important urban feature, often in association with the social sustainability. As cities around the world are experiencing rapid population growth, creating meaningful and enjoyable public spaces is more important than ever.

The heightened interest in social sustainability, public spaces and placemaking (as a physical manifestation of social sustainability) has led to the emergence of several urban intervention movements, such as Tactical Urbanism. In 2012, for the first time in Los Angeles’ history, this tactic was used to transform a car trafficked street in Silver Lake into a pedestrian friendly public space: the Sunset Triangle Plaza. The aim of this thesis is to, by studying the use and function of the plaza after the conversion, highlight how a broad concept such as social sustainability can be understood from a relatively small-scale public space intervention.

The case study was conducted during the spring and summer of 2018, using a variety of data sources including interviews and observations of the plaza during February and March 2018. Two interviews were conducted with managers of the businesses directly adjacent to the plaza. Moreover, street surveys were conducted on two different occasions to ask the public about their use and opinions about the plaza. The results from the case study are presented to illustrate the real-life experience of the theories about social sustainability, public space and a discussion regarding “Whose Public Space?”, when applied at a local context. The findings were then further divided into three categories: usage (what type of activities did the installation enable?), users (for whom were they enabled?) and change (indicators of how the site has changed), reflecting the notions of Tactical Urbanism.

While certain changes have been merely “tactical”, others were more substantial; businesses flourished, traffic safety increased, the space has become a meeting place and therefore, it has now got an identity. Immediate change was evident in the process of the physical change when the plaza was constructed, but what has also followed is a continuous change. Even though the plaza with its painted dots may not look like much, a new space for engagement and interaction has been created, both physically and mentally. In addition, converting a street for the cars into a plaza dedicated to pedestrians is especially symbolic in a city like Los Angeles, where the automobile has been the predominant mean of transport for the last 60 years and instrumental in shaping the city’s layout. However, the case study also showed that it is one thing to launch a Tactical Urbanism initiative and another thing to maintain it and achieve long-term social changes.

The examined concepts and models to evaluate whether a public space can be considered successful are not always useful. The Sunset Triangle Plaza has certainly changed, but it has implied a continuous change – for better and for worse. Thus, this study also shows that it is evident that the idea of the “organically emerged” city can imply both opportunities and limitations.

• KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
Manifestation of Urban Segregation in the Urban Form2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis

Segregation in urban areas is a universal phenomenon. A combination of factors include but are not limited to: city form, planning policies, policies relating to the settlement of immigrants, economic policies, building of infrastructure and chronological events in the growth of a city. Through this thesis work, I would like to examine how urban form is different in areas of the city where racial/ economic segregation is prevalent in Stockholm city. The hypothesis which I would like to examine through study is : The development and maintenance of urban form(which stands to denote all elements relating to the urban area: roads, pavements, lighting fixtures, buildings, public services etc) is influenced by segregation in the city, and it reflects and in turn reinforces the prevalent segregation.

• KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
Custom Base Maps for Utility Network Applications2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Web maps are today used more than ever. These are often displayed in geographical information system solutions. Web maps are often constructed in the terms of different layers where the bottom-most layer is called base map or background map. A specific kind of base maps are those that are the canvas for utility networks. These base maps can look vastly different from each other. Sometimes the base map can be overlooked. Currently there are different theories and opinions on how these base maps shall be designed and what information they shall contain. This thesis investigates a suitable base map design for utility network management and also creates some prototypes as a proof of concept. The thesis focus mostly on three factors, colour, information visualisation and symbology. This is investigated by using a user-centred design approach and comparing it to existing findings in literature and among map theories. The user-centred design process involves a case study performed with participants that work with utility networks in web map solutions. The research method is an iterative process where the participants are answering three quantitative surveys. The surveys includes prototypes which is refined for each step after analysing the participants answers. The thesis concludes that low saturated colours is good practise to enhance the network, this is both evident in literature as well as in the case study. Amount of lightness in the base map seem to be more of a opinionated matter and can highly differentiate depending on users device. Using hue is recommended to make borders between map elements more distinct. The base map shall only obtain the most relevant information and more specific information is recommended to be added through additional layers. Further studies need to be done in order to investigate the networks design and there is also a need to investigate how a map solution with several layers shall be design and how the relationships between those layers shall be constructed for utility network management

• KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
Aging of FeCrAl Surface Coatings2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

This Thesis is about the aging of FECRAL surface coatings. In this thesis various substrates have been investigated such as 16 Mo3, 304, 347, Sanicro 31, 800HT, Nikrothal 80 and Kanthal APMT. These substrates have been coated with different FeCrAl alloys, using two different coating methods spraying with (High Velocity Air Force) and welding with (Metal Inert Gas).

The purpose of coating is to achieve specific properties of the layer without affecting the original properties of the substrate. Therefore, it is important to investigate the boundary layer between these two different materials to observe how the interdiffusion of different substances such as Cr, Al, Fe and C is affected, which is the purpose of this project.

The method used to investigate this purpose was to expose these combinations in different temperatures and in different environments for different time intervals. Then, using LOM, SEM and EDS analysis, the change that the boundary layers have undergone is examined. Some calculations in DICTRA have also been performed to see if it was possible to find any connection between experimental data and simulation results.

The result showed carburization of FeCrAl-coatings on 16Mo3 substrates which can lead to deterioration of mechanical properties in the substrates but also decreased corrosion resistance for the coated layers. The result has also shown that it is difficult to perform spraying for small cylindrical products. The reason for this may be the high powder dispersion and the expansion of certain products when spraying, which causes the layer to loosen due to the shrinkage followed by cooling. APMT sprayed with Nikrothal 80 has shown high porosity in the substrates and high interdiffusion of Fe and Ni. High Ni diffusion in low Al alloys such as K 198 may be a reason why the coated layer cannot optimally form the protective oxide.

• KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
A Topological analysis of an alternative to the PageRank algorithm in weighted directed graphs2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

In this thesis I use seven data-sets of weighted, directed graphs and present them as weighted, directed k-simplicial complexes. Then, I analyse the topological properties of each data-set in question using Flagser by \cite{flagser} and the cluster at the TU Darmstadt. I then proceed to run two versions of an alternative to the PageRank algorithm. One version contracting and deleting every node visited, and the other deleting only those visited nodes with less than 3 neighbours. I record snapshots of how the data-sets throughout the run of the algorithm, and compute the same topological properties computed before the run. I compare the changes in their homology to understand how the algorithm alters the topology of the graph. I also run several runs of the algorithms to get an idea of how the average graph looks like after the algorithm has been run. I record their new topological properties to find a correlation between the performance of the algorithm and the change in the topology of the graphs.

• KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
KTH, School of Electrical Engineering (EES), Micro and Nanosystems. KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
A Silicon Micromachined 220-330 GHz Turnstile Orthomode Transducer (OMT) in a Low-Loss Micromachining Fabrication Platform2018Conference paper (Refereed)

The work presented in this paper reports on the first wideband OMT in any frequency band implemented by micromachining. This turnstile-junction design provides full waveguide-band operation (220-330 GHz) and is the first implementation of a turnstile-OMT above 110 GHz, since very accurate fabrication is required for this topology. The measured insertion loss is below 0.5 dB and below 0.6 dB for the two polarizations, respectively, with an average measured return loss of 22 dB. Except for some spikes which still are below 30 dB, the cross-polarization is between 50 and 60 dB.

• KTH, School of Architecture and the Built Environment (ABE), Architecture, Urban Design.
Kan utvecklingen av det urbana öka mångfalden av livsmiljöer?2019In: Rurban Planning Talks / [ed] Nils Björling, Mariestad: DaCapo Mariestad , 2019, p. 24-27Chapter in book (Other (popular science, discussion, etc.))

Rurban Planning Talkds är en dialog mellan akademi och planeringspraktik för att klargöra de problem som pågående urbana och regionala omvandlingar medför. Vi vill utveckla och diskutera de samhällsutmaningar, konflikter och möjligheter som uppstår i skärningspunkten mellan landsbygd och stad. Fokus är alla de kommuner som rymmer både landsbygder och städer, och deras gemensamma arbete för hållbar utveckling.

• KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
Clustering Based Outlier Detection for Improved Situation Awareness within Air Traffic Control2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

The aim of this thesis is to examine clustering based outlier detection algorithms on their ability to detect abnormal events in flight traffic. A nominal model is trained on a data-set containing only flights which are labeled as normal. A detection scoring function based on the nominal model is used to decide if a new and in forehand unseen data-point behaves like the nominal model or not. Due to the unknown structure of the data-set three different clustering algorithms are examined for training the nominal model, K-means, Gaussian Mixture Model and Spectral Clustering. Depending on the nominal model different methods to obtain a detection scoring is used, such as metric distance, probability and OneClass Support Vector Machine.

This thesis concludes that a clustering based outlier detection algorithm is feasible for detecting abnormal events in flight traffic. The best performance was obtained by using Spectral Clustering combined with a Oneclass Support Vector Machine. The accuracy on the test data-set was 95.8%. The algorithm managed to correctly classify 89.4% of the datapoints labeled as abnormal and correctly classified 96.2% of the datapoints labeled as normal.

• KTH, School of Electrical Engineering and Computer Science (EECS).
OSM-Based Automatic Road Network Geometries Generation on Unity2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Nowadays, while 3D city reconstruction has been widely used in important topics like urban design and traffic simulation, frameworks to efficiently model large-scale road network based on data from the real world are of high interests. However, the diversity of the form of road networks is still a challenge for automatic reconstruction, and the information extracted from input data can highly determine the final effect to display.

In this project, OpenStreetMap data is chosen as the only input of a three-stage method to efficiently generate a geometric model of the associated road network in varied forms. The method is applied to datasets from cities in the real world of different scales, rendered and presented the generated models on Unity3D platform, and compared them with the original road networks in both the quality and topology aspects. The results suggest that our method can reconstruct the features of original road networks in common cases such as three-way, four-way intersections, and roundabouts while consuming much shorter time than manual modeling in a large-scale urban scene. This framework contributes to an auxiliary tool for quick city traffic system reconstruction of multiple purposes, while there still being space of improvement for the modeling universality and quality of the method.

• KTH, School of Engineering Sciences (SCI), Mechanics.
Enabling high-fidelity measurements of turbulent boundary layer flow over wing sections in the MTL wind tunnel.2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

A reinforced fiber-glass model of a NACA 4412 wing profile is designed and set-up in the Minimum Turbulence Level (MTL) wind tunnel facility at KTH. The model has 65 pressure taps orifices, and the set-up includes two mounting panels designed to allow for particle image velocimetry (PIV) and hot wire anemometry (HWA) measurements of the boundary layer (to be performed in a future campaign). In a first experimental campaign pressure scans are conducted at three angles of attack of interest (5,10 and 12 degrees), and at four different Reynolds numbers based on chord length and inflow velocity (200,000, 400,000, 1,000,000, and 1,640,000). The preliminary results show good agreement with DNS and LES data, however, the effective angle of attack of the wing is affected by the interference of the test section. In order to obtain proper flow conditions for future campaigns inside the test section, wall inserts are designed using 2D k-omega SST simulations. The side-walls are streamlined and the final geometry is corrected to account for the boundary-layer growth over them. The inserts are shown to avoid early separation near the trailing edge at higher angles of attack (10 and 12 degrees), but the 2D simulations fail to capture the aforementioned angle-of-attack issue affecting the pressure distributions. Future extensions of the present insert design should include both 3D simulations of the test-section and a robust optimization procedure to prescribe the resulting pressure distribution.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Machine Learning for Inferring Depth from Side-scan Sonar Images2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Underwater navigation using Autonomous Underwater Vehicles (AUVs), which is significant for marine science research, highly depends on the acoustic method, sonar. Typically, AUVsare equipped with side-scan sonars and multibeam sonars at the same time since they both have their advantages and limitations. Side-scan sonars have a much wider range than multibeamsonars and at the same time are much cheaper, yet they could not provide accurate depth measurements. This thesis is aiming at investigating if a machine-interpreted method could beused to translate side-scan sonar data to multibeam data with high accuracy so that underwater navigation could be done by AUVs equipped only with side-scan sonars.

The approaches considered in this thesis are based on Machine Learning methods, including generative models and discriminative models. The objective of this thesis is to investigate the feasibility of machine learning based models to infer the depth based on side-scan sonar images. Different models, including regression and Generative Adversarial Networks, are tested and compared. Different CNN based architectures such as U-Net and ResNet are tested andcompared as well. As an experiment trial, this project has already shown the ability and great potential of machine learning based methods extracting latent representations from side-scansonars and inferring the depth with reasonable accuracy. Further improvement could be madeto improve the performance and stability to be potentially verified on the AUV platforms inreal-time.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Exploring A Visualization System For History Paths2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Many business intelligence tools aim to digest data into easy, understandable and visualizable information for helping decision-making, while they are still lack of ability to support visualizing the history of selections. This limitation concerns the coming future when everything is about data. Due to it, users are not able to share their thinking paths to the decision. Here a history selection path means a sequence of previous selections. As an approach, it helps users in decision-making and discovery insight. This study investigated an efficient graphical visualization system of history selection paths to support communicating and iterative analysis. We selected tree representation as the main visualization model and also propose features needed for the system.

Specifically, we researched the significance of this study, existing solutions and also the proper designs and functions for the idea. It is initiated by user research including targeting users and scenario mapping. Based on the understanding, we applied a parallel design to narroww down the suitable design. As a result, tree representation was selected as the visualization model. To evaluate whether it touched user needs or not, we applied usability test to collect quantitative data and qualitative comments. For making the test environment as real as possible, a webbased interactive prototype supported by D3.js library was implemented for testing. We analyzed the user experience and also consolidated improvements. As a case study, we implemented the solution on Qlik Sense to verify the possibility to place this solution into real data visualization tool.

Generally, the result of this study formed a valuable initiative for further development and we saw potentials of this tree model system to be used in other areas when it comes to reviewing history as well.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Investigating differences in response time and error rate between a monolithic and a microservice based architecture2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

With great advancements in cloud computing, the microservice architecture has become a promising architectural style for enterprise software. It has been proposed to cope with problems of the traditional monolithic architecture which includes slow release cycles, limited scalability and low developer productivity. Therefore, this thesis aims to investigate the affordances and challenges of adopting microservices as well as the difference in performance compared to the monolithic approach at one of Sweden’s largest banks, SEB - the Scandinavian Individual Bank.

The investigation consisted of a literature study of research papers and official documentation of microservices. Moreover, two applications were developed and deployed using two different system architectures - a monolithic architecture and a microservice architecture. Performance tests were executed on both systems to gather quantitative data for analysis. The two metrics investigated in this study were response time and error rate.

The results indicate the microservice architecture has a significantly higher error rate but a slower response time than the monolithic approach, further strengthening the results of Ueda et. al. [47] and Villamizar et. al. [48]. The findings have then been discussed with regards to the challenges and complexity involved in implementing distributed systems. From this study, it becomes clear the complexity shifts from inside the application out towards infrastructure with a microservice architecture. Therefore, microservices should not be seen as a silver bullet. Rather, the type of architecture is highly dependent on the scope of the project and the size of the organization.

• KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Communication Systems, CoS, Network Systems Laboratory (NS Lab).
Universitat Politècnica de Catalunya. Queen Mary, University of London. Independent Researcher. AGH University of Science and Technology in Kraków. Barefoot Networks. University of Vienna.
PURR: A Primitive for Reconfigurable Fast Reroute: (hope for the best and program for the worst)2019In: In International Conference on emerging Networking EXperiments and Technologies, , 2019 / [ed] ACM, 2019Conference paper (Refereed)

Highly dependable communication networks usually rely on some kind of Fast Re-Route (FRR) mechanism which allows to quickly re-route traffic upon failures, entirely in the data plane. This paper studies the design of FRR mechanisms for emerging reconfigurable switches.

Our main contribution is an FRR primitive for programmable data planes, PURR, which provides low failover latency and high switch throughput, by avoiding packet recirculation. PURR tolerates multiple concurrent failures and comes with minimal memory requirements, ensuring compact forwarding tables, by unveiling an intriguing connection to classic string theory'' (\textit{i.e.}, stringology), and in particular, the shortest common supersequence problem. PURR is well-suited for high-speed match\slash action forwarding architectures (e.g., PISA) and supports the implementation of arbitrary network-wide FRR mechanisms. Our simulations and prototype implementation (on an FPGA and Tofino) show that PURR~improves TCAM memory occupancy by a factor of 1.51.5x---10.810.8x compared to a na\"ive encoding when implementing state-of-the-art FRR mechanisms. PURR also improves the latency and throughput of datacenter traffic up to a factor of \mbox{2.82.8x---5.55.5x} and 1.21.2x---22x, respectively, compared to approaches based on recirculating packets.

• KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electric Power and Energy Systems.
KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electric Power and Energy Systems. KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electric Power and Energy Systems. 2ABB Corporate Research, Västerås, Sweden.
Many-objective Optimization of IPM and Induction Motors for Automotive Application2019Conference paper (Refereed)

This paper presents a Pareto-optimality-based optimization methodology suitable for the design of electrical motors in automotive applications. The proposed many-objective evolutionary algorithm is utilized in this study case for the optimization of an interior permanent-magnet (IPM) synchronous motor and an induction motor (IM), considering as criteria the motors' torque capability, efficiency as well as torque density. Finite-element (FE) models of the investigated motor topologies are developed and incorporated in the optimization process in order to ensure an accurate estimation of their electromagnetic performance. The attainment of the targeted specifications by the final optimal designs validates the efficacy of the implemented optimization algorithm.

• KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.).
Biomechanics of AAA surveillance patients2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Abdominal aortic aneurysms (AAA) occurs due to local enlargement of the abdominal aorta and affects about 1-2 % of the elderly Swedish population. At admission, AAA patients receive a Computed Tomography-Angiography (CT-A) scanning, and later they are followed-up by 2D ultrasound examinations. There is a need to know if an adequate geometry can be constructed from the baseline CT-A scan and follow-up 2D ultrasounds. To test our hypothesis only CT-A images have been used from six patients and hypothetical ultrasound cross-sections (HUCS) were extracted from the follow-up CT-A scans. The baseline AAA surface was expanded in a mechanical model by applying pressure inside of it until it reached the HUCS. The obtained morphed geometries were then compared with the CT-A-based geometries. The discrepancy between them were calculated by distance measurements. Also, the rupture risk indicators volumes and stresses were compared. Finally, a sensitivity analysis studied the effect of HUCS positioning on the volumes and stresses. The results show that an adequate geometry can be constructed by the investigated concept of morphing. The average distances between the morphed and CT-A-based geometries are 2-4 mm. The average volume difference for the six patients are between 3.8-16.2 %. The wall stress for the morphed and CT-A-based geometries are close only for the first follow-up.

• KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
Implementation and validation of an isogeometric hierarchic shell formulation2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Within this thesis, thin walled shell structures are discussed with modern element formulationsin the context of the Isogeometric Analysis (IGA). IGA was designed to achieve a directinterface from CAD to analysis. According to the concept of IGA, Non-Uniform RationalB-Splines (NURBS) are used as shape functions in the design and the analysis. Dependingon the polynomial order, NURBS can come along with a high order continuity. Therefore,the curvature of a shell surface can be described directly by the shape function derivativeswhich is not possible within the classical Finite Element Analysis (FEA) using linear meshes.This description of the curvature gives rise to the application of the Kirchho-Love shellformulation, which describes the curvature stiness with the dierentiation of the spatialdegrees of freedom. Based upon this, the formulation can be enhanced with further kinematicalexpressions as the shear dierence vector, which leads to a 5-parameter Reissner-Mindlinformulation. This kinematic formulation is intrinsically free from transverse shear lockingdue to the split into Kirchho-Love and additional shear contributions. The formulation canbe further extended to a 7-parameter three-dimensional shell element, which considers volumetriceects in the thickness direction. Two additional parameters are engaged to describethe related thickness changes under load and to enable the use of three-dimensional materiallaws. In general, three-dimensional shell elements suer from curvature thickness and Poisson'sthickness locking. However, these locking phenomena are intrinsically avoided by thehierarchic application of the shear dierence vector and the 7th parameter respectively. The3-parameter Kirchho-Love, the 5-parameter Reissner-Mindlin and the 7-parameter 3D shellelement build a hierarchic family of model-adaptive shells.This hierarchic family of shell elements is presented and discussed in the scope of this thesis.The concept and the properties of the single elements are elaborated and the dierences arediscussed. Geometrically linear and non-linear benchmark examples are simulated. Convergencestudies are performed and the results are validated against analytical solutionsand solutions from literature, taking into account deections and internal forces. Furthermore,the dierent locking phenomena which occur in analyses with shell formulations areexamined. Several test cases are designed to ensure a validated implementation of the hierarchicshell elements. The element formulations and further pre- and postprocessing featuresare implemented and validated within the open-source software environment Kratos Multi-physics.

• KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
Design of a low carbon building: Case study of an architectural competition2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Greenhouse gases (GHGs) emissions due to human activities have considerably increased in the past decades which are the main contributors of global warming. In order to limit the consequences of the global climate change happening, all sectors must reduce their carbon emissions and especially the building industry which represents 19% of the carbon footprint of human activities. This paper is giving methods to help reduce the carbon footprint of a building when designing it such as life cycle assessment which allow project teams to compare the global warming potential of all building materials. Those methods are used and challenged in a case study of an architectural competition project named quai d’Issy in Paris, France. Using biobased materials help reduce the carbon footprint of a building, a structure made of timber and concrete elements can emit less than 21% of GHGs than a classic concrete structure. By sourcing reused and recycled building materials, by using geothermal heat pump as heating and cooling systems for example, we have been able to reach for the quai d’Issy project a carbon footprint of 930kgC02eq/m2 of floor area, which is less than level needed for the highest French environmental certification. However, these results can be obtained only if the building materials companies continue their work to develop low-carbon materials and promote recycled and reused materials. This study emphasises the need to spread knowledge of the tools to design low-carbon building to all the actors of the building industry in order to promote behaviours that will limit the consequences of climate change.

• KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning.
Analysis of Walking and Route-Choice Behavior of Pedestrians inside Public Transfer Stations: A Study on how pedestrians behave in the approaching vicinity of level-change facilities,and how it affects their walking and route-choice behavior2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Pedestrian walking and choice behavior presented was first studied by Fruin in 1971, and since then a lot of research have been carried out in order to understand how humans move and what does make them make choices and obtain certain patterns. In relation to pedestrians, a significant bottleneck inside public stations evaluated by research are the level-change facilities, as Stair Walks and Escalators. The aim of this research is studying how pedestrian behave in the vicinity to stairways and escalators, and how does that affect pedestrian choice, speed and acceleration when choosing one of the two facilities. Also, with a need for more data on pedestrian traffic, further data collection is a big requirement to analyze their behavior and use as tools in future measures. At last, how to optimize the movement of pedestrians in relation to level changes, considering the effects of the movements observed. Two case studies were analysed, Stockholm Central Station and Uppsala Central Station.The study compares data collection methods, tracking methods and previous studies to better fit the scope of this research. The data is backed up from previous research and explains which method better fitted the options available. As a result, video data collection was chosen to collect the data, a semi-automatic tracking software called T-analyst was used to extract speed, trajectories and acceleration from the videos, and microsimulation modelling from VISSIM further investigated different design options to optimize the overall performance and improve travel time in the same area. The analysis found out that there was a possibility to increase the overall performance of the location in higher flow levels, where the most significant queues could be seen, since there was the possibility to achieve higher speeds by modifying the width and position of the stair walks, which allow for a smaller queue in both directions.

• KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
Evaluation of air entraining behaviour in concrete using computer aided methods on hardened samples2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Increasing awareness of sustainability in the concrete industry forces structural design and executionto focus on avoiding costly and unpredictable maintenance action, instead paying higher attention todamage prevention by direct actions on early stages of production. One of such approaches, whichdeals with the problem of freezing and thawing deterioration, is intentional air bubble introductionto the concrete mix. However, the mechanism of air entrainment in concrete can be negativelyaffected on different stages of production by many factors including cement type, admixture dosage,casting conditions or mixing procedure. Therefore, reliable tools for the end-product evaluationought to be considered. The experimental study, presented in this work, focuses on understandingthe blast furnace slag (BFS) influence as well as admixtures’ dosage effect on pore structure ofhardened concrete. Three types of cement were evaluated, including ordinary portland cement(OPC) and two types of CEM III cements with different BFS percentage. The optimal amountsof air entraining agent (AEA) and super plasticizer (SP) were chosen and later reduced in orderto evaluate their impact on total air content, spacing factor and specific surface of the air voids.The main method chosen for this evaluation was the use of an office flat-bed scanner to acquireimages and application of BubbleCounter software for the analysis of the air void structure. Thisapproach is based on linear traverse method and requires special surface treatment for contrastenhancement. Specimens for the analysis were cut from hardened concrete cubes and polishedto achieve a flat surface. The samples were later treated with black ink and zinc oxide paste toachieve a clear contrast between white voids and black paste/aggregate area. In order to estimatethe accuracy of this method, more conventional tools such as pressurised gauge method and air voidanalyser were applied for comparison. Resulted mixtures showed significant differences in air voidproperties between OPC and BFS containing concrete, with the latter being less affected by AEAdosage reduction. Changes in spacing factor and specific surface were also registered; however,their deterioration did not follow the same pattern as that of total air content. No significantdeviation between the two cements containing BFS was observed. An interesting effect of the usedpolycarboxylate ether SP on the AEA reactivity was registered, showing deterioration of air voidproperties with the decrease of plasticizer amount. Comparison of the results from different air voidanalysis methods, suggested an overall agreement on the measured air void system changes due tochanging the AEA content. However, the BubbleCounter software tended to slightly overestimatethe material’s resistance to freeze and thaw phenomenon, giving the most optimistic values inspacing factor and specific surface of air voids.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Robotization as a driver of increased labour productivity and economic convergence or divergence in the European Union2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

During the years 2004-2014, the manufacturing sector within the EU countries witnessed an increase in the utilization of industrial robots, where robot density per worker approximately doubled. Considering that this is a rather recent event, studies investigating how much industrial robots impact labour productivity are still rare. At the same time, one of EU’s outspoken goals is that of working to foster productivity and economic convergence between the member states. Given the above premises, we have investigated the relation between the adoption rate of industrial robotics within the EU and its effect on labour productivity.

Secondly, we have made a predictive convergence model, in terms of labour productivity. We have collected data from several sources, including the Industrial Federation of Robotics and EU KLMS, in order to build a dataset for our quantitative analysis. We have then used statistical methods such as multiple regressions and 3 stage least square analysis (3sls) to estimate our system of interdependent equations model. The results show that implementation of industrial robotics in the manufacturing sector is a driver of labour productivity. The model finally predicts upward labour productivity divergence between the member states in the years 2015-2025, assuming that the determining factors of labour productivity grow at the same pace in our forecast period as in our data sample.

• KTH, School of Industrial Engineering and Management (ITM).
Utveckling av kursmoment för kemiundervisning: En undersökning av gymnasieelevers kunskapsutveckling i samband med lärandeaktiviteter rörande kemisk analys och hållbar utveckling2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

In this research, the knowledge development of a group of high school students during a course component was studied. The course component, which consisted of four separate parts, was developed for this investigation. The students who participated in the investigation are all in year one in high school, and study at the Science programme. The course component was included in their chemistry course. The course component was developed to increase the students’ knowledge within selected topics from the curriculum, however, also to offer the postulation to develop Scientific Literacy, as well as to increase their ability to discuss societal issues while including a scientific perspective. To be able to carry out the investigation, two different data selections were accomplished. One where the students responded to a survey, where they had to reflect upon their own knowledge development, and another, where their subject knowledge was examined during the assessment of an assignment that they had to carry out as the last part of the course component. The instructions for the assignment was to first describe different analytical tools used in chemistry, and secondly, to narrate different solutions on how to deal with environmental issues, using a perspective of sustainable development. The conclusion drawn from this research is that the course component provided the students the opportunity to increase their knowledge and their strengthen abilities within the requested subject areas. However, it also emerged from the study that, if the different parts om the course component were to be adjusted, the result might have been more successful and the correlation between the course component and the main purposes for it to be carried out might had been stronger. The didactical process that has been carried out during this work has also been analysed. Hence, suggestions about how to reflect upon time requirements and work organisation if one, as a teacher, wishes to either implement this course component in their own tutoring, or do something similar, is presented in the end of this report.

• KTH, School of Industrial Engineering and Management (ITM).
Organizational learning through knowledge sharing:: A study regarding influential factors of knowledge sharing between developers of an IT-consultant organization.2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

This study aims to understand the knowledge sharing process between developers within an IT-consultant organization. As with today’s fast-paced and knowledge-driven society, there’s been a growing interest within organizations to manage their collective knowledge. Thus, this study doesn’t merely focus on what’s currently going on in a specific setting, but also what can be done to further influence the process of knowledge sharing.

Previous research within the field of knowledge sharing has been studied, mainly based upon the theoretical framework developed by Minu Ipe (2003). This study has been further divided into several influential factors regarding the process of knowledge sharing. We, therefore, strive to understand where the act of sharing knowledge occurs, how the employees learn from one another and what motivates them to participate in the process. This was done through qualitative methods, where several employees and a few representatives of the management of a certain organization were interviewed. The results gathered were further analyzed and conclusions were made regarding future improvements to the knowledge sharing process. Social and communicational aspects were determined to be core influential factors of knowledge sharing.

• KTH, School of Industrial Engineering and Management (ITM).
“Factors Influencing FDI Inflows in SouthAsian Countries: A Panel Data Analysis”2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Foreign direct investment (FDI) is played a vital role for boosting up the economies of developing countries. Hence, it is necessary to know the factors that determines the flows of FDI in the developing countries. This study has attempted to investigate how different factors affect the inflow of foreign direct investment in South Asian Countries. To attain the objective this study has collected data on the respective variables for 45 years and considered seven countries. The relationship between different economic variables and their overall impact on FDI inflows have been examined through various panel models like basic pooled OLS estimation, entity fixed effect model, time fixed effect estimation and random effect model. The outcome of this study is that GDP of the country is the main factor behind the FDI inflows in South Asian countries.

• KTH, School of Engineering Sciences (SCI).
KTH, School of Engineering Sciences (SCI).
Interscale transport of Reynolds stresses in wall-bounded flows2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Couette, pipe, channel, and zero-pressure gradient (ZPG) turbulent boundary layer (TBL) flows have classically been considered as canonical wall-bounded turbulent flows since their near-wall behavior is generally considered to be universal, i.e. invariant of the flow case and the Reynolds number. Nevertheless, the idea that large-scale motions, being dominant in regions further away from the wall, might interact with and influence small-scale fluctuations close to the wall has not been disregarded. This view was mainly motivated due to the observed failure of collapse of the Reynolds normal stresses in viscous scaling. While this top-down influence has been studied extensively over the last decade, the idea of a bottom-up influence (backward energy transfer) is less examined. One exception was the recent experimental work on a Couette flow by Kawata, T. & Alfredsson, P. H. (Phys. Rev. Lett. 120, 244501, 2018). In the present work, a spectral representation of the Reynolds Stress transport equation is used to perform a scale-by-scale analysis of the terms in the equation. Two flow cases were studied: first, a Direct Numerical Simulation (DNS) of a Couette flow at a similar Reynolds number as Kawata and Alfredsson. The Reynolds number was ReT = 120, viscosity v. Second, a Large Eddy Simulation (LES) of a ZPG TBL at ReT = 730, 1270, and 2400. For both cases the classic interscale transport or turbulent kinetic energy was observed. However, also an inverse interscale transport of Reynolds shear stress was observed for both cases.

• KTH, School of Industrial Engineering and Management (ITM).
A Novel, Wave-based Control Architecture for Collaborative Haptic Virtual Environments2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Haptic feedback, the introduction of sense-of-touch into virtual environments, has been shown to have many benefits in practical applications. One such area of interest, is the increased performance of tasks that require collaboration. In the literature however, a tradeoff has been identified between transparency and consistency among remotely connected users.

The purpose of this thesis is to explore the realisation of a hybrid network architecture to try to gain the transparency benefits of a peer-to-peer (P2P) architecture, and the consistency and scalability benefits of a client-server (CS) architecture. Unlike the conventional CS case where the client only has a static local copy of the object, the hybrid architecture introduces a dynamics engine on the client side. There is still a central node in the topology, designated the Observer, which contains the central model and all information about the virtual environment. To maintain consistency, the Observer is connected to each client model by a consensus controller, which act as a virtual coupling.

Different distributed control strategies and choice of parameter distributions are investigated and evaluated in simulation. To ensure passivity, and thus stability, wave variable transforms are proposed as an alternative to power variables, which also removes the controller design from the analysis. A passivity-preserving, prediction-based reflection compensation algorithm is also proposed to improve the user experience during collaboration. The proposed solution is generalised for an arbitrary amount of users, for any degree of freedom, while the evaluation is limited to two users in a 1-DOF use-case.

Finally, a comparison is performed in simulation between the proposed hybrid architecture and the state-of-the-art P2P and CS architectures. The findings are evaluated in regards to stability, consistency, and transparency.

• KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Management.
Work functions shaping the ability to innovate: insights from the case of the safety engineer2019In: Cognition, Technology & Work, ISSN 1435-5558, E-ISSN 1435-5566Article in journal (Refereed)

To perform as intended, firms are divided into work functions that contribute to the behaviour-shaping constraints under which individuals build their skills, knowledge and networks. These in turn provide a specialized perspective on organisational structure and culture. In a mixed methods study involving interviews and statistical analyses, we investigate whether a work function can thereby affect individuals’ innovation foci and efficacy. Safety engineers, central to firms developing Cyber-Physical Systems (CPS), are shown to play a significant role in identifying and supporting viable innovation related to organisational aspects. Results indicate that safety engineers could use the firm’s collaborative innovation process to facilitate organisational learning, helping different work functions come together to construct working practices aligned with the organisational values of the firm. This is explained by their understanding of safety culture—a specialized understanding of organisational culture and complexity provided by their work function. We conclude that work functions that provide their members with a perspective well aligned with their firm’s organisational values can instil the ability to identify and support organisational innovation. This suggests that safety engineers in CPS domains could be effective in a mediatory role, facilitating innovative changes to organisational structures and processes when introducing and operating safety management systems. Stronger aspects of organisational liaising and systems thinking could reinforce this ability—the former by a wider scope and motivation leading to an increased skill in communicating with dissimilar individuals, and the latter by providing the skills and tools needed to analyse the politics of complex organisations.

• KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems. KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Micro and Nanosystems.
Dielectric Rod Antenna Array for Photonic-Based Sub-Terahertz Beamforming2019Conference paper (Refereed)

This work presents a dielectric rod antenna array designed for a photonic-enabled beamforming system at subterahertz frequencies. The photonic chip generates an optical group delay, providing the beam-steering capability. The antenna array is fabricated from high-resistivity silicon by micromachining. Simulation results demonstrate a directivity of 14.7 dBi and a beam steering range of 56 degrees at 85 GHz. The system is intended as a sub-THz transmitter for broadband wireless communications.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Generative Adversarial Networks in Text Generation2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

The Generative Adversarial Network (GAN) was firstly proposed in 2014, and it has been highly studied and developed in recent years. It has obtained great success in the problems that cannot be explicitly defined by a math equation such as generating real images. However, since the GAN was initially designed to solve the problem in a continuous domain (image generation, for example), the performance of GAN in text generation is developing because the sentences are naturally discrete (no interpolation exists between “hello" and “bye").

In the thesis, it firstly introduces fundamental concepts in natural language processing, generative models, and reinforcement learning. For each part, some state-of-art methods and commonly used metrics are introduced. The thesis also proposes two models for the random sentence generation and the summary generation based on context, respectively. Both models involve the technique of the GAN and are trained on the large-scale dataset. Due to the limitation of resources, the model is designed and trained as a prototype. Therefore, it cannot achieve the state-of-art performance. However, the results still show the promising performance of the application of GAN in text generation. It also proposes a novel model-based metric to evaluate the quality of summary referring both the source text and the summary.

The source code of the thesis will be available soon in the GitHub repository: https://github.com/WangZesen/Text-Generation-GAN.

• KTH, School of Electrical Engineering and Computer Science (EECS).
FoodEd: Encouraging sustainable food waste practices through an informative app2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Every year 1.6 billion tons of food is thrown away corresponding to one third of all the food that is roduced. It accounts for 8 % of the global greenhouse gas emission, meaning that it has a huge negative impact on the environment. In Sweden, households account for the largest amount of food waste. Therefore, this study focuses on reducing food waste on a household level in Swedish households.

There is a growing interest in HCI for how design can be used for reducing food waste by changing unsustainable behaviour. In this work a working mobile prototype, FoodEd, was designed, implemented and studied. FoodEd contains information of how to handle and store different food items in an optimal way. The aim was to raise awareness of good food handling practices and edibility beyond expiry dates in order to prevent unnecessary food waste in households.

In this study, FoodEd was used by 10 participants during a week’s time. Two qualitative interviews were held with each participant during the study. The findings of the study indicate that an informative design can be effective in providing relevant information for its users leading to more sustainable food waste behaviours.

• KTH, School of Electrical Engineering and Computer Science (EECS).
An Explorative Study of Interaction with Tracked Objects in a Virtual Reality Game2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

In recent years, Internet enabled objects (Internet of Things) and their augmentation through virtual reality has become both technically possible and increasingly advanced. This paper explores how interaction between physical IoTs and their virtual and digital twins can be advanced. Three virtual reality games focusing on three different interactions were created. One game focused on rotating, another on pushing and pulling, and a third on lifting and dropping. All games revolved around the use of real tracked cardboard boxes which were represented in the games by a virtual box in the same relative position and rotation to the player, allowing participants to manipulate the virtual boxes by manipulating the physical boxes. 14 participants were asked to play the games and were afterwards interviewed in regards to the games, their interactions with them, their enjoyability and their thoughts regarding them and the concept in general. The results were acquired from game performance, the reflections of the participants, and the subsequent analysis of recorded audio and video. The study presents the difficulties, challenges and opportunities of such a system, while also providing insight into lessons learned from the creation of the system and the games. The main contributions of the paper are the lessons learned in creating the games and experiences in addition to a few specific areas of interest for future research on the area, namely the importance of ergonomic consideration and affordance evaluation.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Key Tension Points of creative Machine Learning applications keeping a Human-in-the-Loop2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Machine learning (ML) and artificial intelligence (AI), might have earlier primarily found industrial use, improving production chains, efficiency and the like but are now an integral part of private and commercial application. Many systems are using, or are claiming to use, machine learning to improve the end user's experience.

This study aims to explore applications that are using creative ML, in which output might have a plethora of solutions instead of a single correct one. More specifically the focus is to evaluate which Key Tension Points, central lesser components of a complex and bigger issue, arise for researchers, designers and users coming into contact with this technology.

The goal is to draw upon these Key Tension Points and attempt to frame guidelines which researchers and designers can use to further their understanding of the relationship between ML and design and how they can be accounted for to build and develop better application. The study found that these tension points (Impersonality, passive consumers & transparency) vary considerably depending on the application and presents how designers can account for them.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Framgångsfaktorer inom digital livsmedelshandel: Samsyn och skillnader mellan konsumenter och aktörer2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

In this research the differences and consensus between the consumers and the actors perception of the crucial success factors within Swedish online grocery shopping are being analyzed.

Online grocery shopping is one of the fastest growing markets in Sweden. The online grocery shopping market encompasses both pure digital players and major hybrid actors with a combination of online and offline sales.

The main result in this report show that consumers and actors agree on some of the main issues even though the actors seems to overrate the importance of making the webpages personalized with each customers favorites. At the same time they seems to underrate the importance of keeping the price at the same level as physical stores and the importance of favorable membership. There is consensus on the importance of an easy-to-use webpage and home delivery being the crucial form of delivery.

It is of greatest importance that the actors develop strategies that make them relevant and attractive to consumers, competitive in the market and also profitable. The market is in a very interesting phase right now, experiencing high growth and there is a lot of potential for successful actors. Big strategic decisions and large investments are being made, but as this research suggests not always on things that really could make a difference for the consumers and could make them loyal to one actor and give that actor a greater part of their spend.

• KTH, School of Industrial Engineering and Management (ITM).
Initial Assessment ofManufacturing ExecutionSystems: Development of a methodology to definebusiness needs and functional requirements2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

A key component of the smart factories that industry 4.0 introduce is the MES (manufacturing executionsystem). The MES lies above the actual shop floor in the enterprise system hierarchy and is not in directcontact with the actual production, in the way PLC (programmable logic control) or SCADA (supervisorycontrol and data acquisition) systems are. MES guide, initiate, respond to and reports on the productionactivities as well as distribute information to other company IT systems, bridging the gap between thecontrol systems of the shop floor and the information systems on an enterprise level. MES is a class ofinformation systems built to support shop floor processes and improve the integration to other departmentsof the enterprise by incorporating these systems into the overall IT-architecture. The main goal of an MESis to improve and optimize the production management functions and increase visibility into themanufacturing process.

The role of the MES is defined by industry standards that identify what functionalities and dataflows anMES should include, and how it is intended to be integrated with other information systems. However, littleresearch has been focused on adopting these standards in actual MES implementation projects. The MESA(manufacturing executions system association) is presenting a standardized definition of MES as well as 2models of the, according to the standard, 11 key MES functionalities. The ISA-95 (IEC/ISO 62264)standard identifies sub-systems of an MES and defines the boundaries between the ERP, MES and otherautomation and IT systems. Company parameters such as manufacturing environment, production modeland plant type all affect the business needs and what MES functionalities are of priority. Hence, for an MESimplementation project, a business-specific evaluation must be performed.

Prior research in the area is presenting a high-level workflow and best-practices of an MES implementationproject. By combining this workflow with the general software implementation standard ISO/IEC 12588(ISO/IEC 15288: System engineering – System lifecycle process), a methodology for performing the initialassessment of a company’s MES needs and business requirements is built. In the methodology models fromMESA and ISA-95 are applied to ensure an industry-accepted terminology and process. The objective ofthe methodology is to provide a standardized way to make an initial assessment of a company’s MES needsand specify system requirements. The methodology is validated through a study performed at discretemanufacturing line.

The overall needs and specific functional requirements are identified through the methodology and arepresented according to a URS (user requirements specification) for an MES. The requirements areprioritizing according to MoSCoW analysis. Additional validation of the methodology must be performedto further evaluate the suitability of using the methodology for initial assessments of businesses’ MES needs.

• KTH, School of Industrial Engineering and Management (ITM).
Conceptualization anddevelopment of a standardizedframework for virtualcommissioning of modularassembly control systems2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Today’s industries are challenged by an ongoing trend of more product variantsto meet differing customer needs. This leads to efficiency losses within traditionalproduction systems using fixed cycle times within an assembly line. Contrarily,flexible modular assembly systems are seen as a promising solution. These are characterizedby offering flexible routes of the products throughout the production system.Utilizing the capabilities of cyber-physical production systems, automated guidedvehicles are performing the transports of workpiece-carriers in-between decoupledworkstations. In order to manage the complexity, sophisticated control approachesare required to coordinate all involved entities. These are organized either in acentralized or decentralized manner. For the performance evaluation of both types ofalgorithms concerning parameters characterizing the factory layout, no standardizedframework exists.

Following the principles of virtual commissioning, this work presents a frameworkcomposed of three elements: a flexible simulation model representing a modularassembly system, a multi-agent system incorporating the logic of centralized ordecentralized control approaches, and an interface for data exchange.The framework has been successfully validated by incorporating a centralized approachfollowing a global schedule and a decentralized approach using a negotiationbasedagent-system which controls the production flow.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Hur förändrar smart teknik resurseffektiviteten i fordonsbranschen?: En studie av hur Cyber-Physical Systems och Internet of Things påverkar resurseffektiviteten i personbilsbranschen2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

Today, there is much talk about smart technology and it is said that the fourth industrial revolution is on its way. The revolution is called Industry 4.0 and involves two technical improvements, the Internet of Things (IoT) and Cyber-Physical Systems (CPS). IoT allows physical devices to be interconnected in a system with other devices using electromagnetic waves and CPS provides the opportunity to get information from the outside world and implement the information in digital form. When it comes to implementation in the manufacturing industry, the concepts Industrial Internet of Things and Cyber-Physical Production Systems are used.

The thesis consists of an in-depth literature study and investigates what implementation of IoT and CPS in the automotive industry's manufacturing system can lead to and how they work in practice. The theory is based on scientific articles, paper and journals, and a study by Atlas Copco. Because smart technology is a broad topic and we needed to relate to a time limit of 18 weeks, the work was limited to IoT and CPS only in manufacturing passenger car companies. The industry for passenger cars was chosen so that, in comparison with other industries, both the quality and the quantity are decisive. While many passenger cars are being produced, each passenger car must meet a variety of requirements and each unit constitutes a significant part of the capital of the company.

The result shows how IoT and CPS work as a whole and what positive and negative consequences the implementation of the concepts gives. The result also shows that the factors of production, economy and humanity should be analysed as a whole and not individually in order for the implementation to be successful in manufacturing passenger car companies.

The opportunities that IoT and CPS entail are faster and more precise decisions, system monitoring and collection, exchange and analysis of data for the automotive industry's companies. The biggest challenge that the implementation of the concepts entails is data management. There is a risk that unwanted recipients will have access to confidential information through, among other things, data leakage and hacking. Thus, the focus should be on preventing this in order to get the benefits and at the same time reduce the disadvantages.

The conclusion that can be drawn from the result is that IoT and CPS in the automotive industry's manufacturing system create a communication network among heterogeneous units that enable systems to communicate and exchange data with each other in an efficient manner. Implementation of the concepts leads to a reduction of defects, introduction costs, energy use and training for workers, as well as increased tool operation and productivity.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Resurseffektiv produktion i tillverkande företag: -Ur ett hållbarhetsperspektiv i en kvalitativt hantverksproducerande verksamhet2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

The increasing global population in combination with finite resources places demands on how resources are used. Mass production was a consequence of the assembly line introduced by Henry Ford in manufacturing processes, and in order to enable product variation, Toyota developed the production process by introducing the Toyota Production System and Lean Production, which focuses on reducing waste.

The concept of Lean Retail is becoming increasingly common in the retail industry, where the benefits of the concept are being implemented in business strategies and manufacturing processes. Cradle to Cradle (C2C) and circular economy are inspired by nature’s own cycles, and concerns eliminating waste. The purpose of this report is to evaluate how a high-quality manufacturing company, which mostly works with craftmanship, has implemented its own sustainability philosophy and to what extent they work with the Lean Retail concept. The company is Svenskt Tenn, and an interview with production and quality manager Johanna Asshoff in combination with a visit at one of their subcontractors is the basis for the empirical study. In combination with that, a literature study was carried out with the help of KTH’s databases, which concerns the topics sustainability, Lean production and circular economy.

As a company, Svenskt Tenn has a clear picture of how they work with their sustainability philosophy. In their own book, ”Svenskt Tenns hållbarhetsfilosofi”, several different dimensions are presented by the company and it is also mentioned that the C2C philosophy has been implemented throughout the process by their linen supplier. There is a sustainability focus behind many of the company’s strategic decisions and since the company has been active for many decades, they have also been involved in how sustainable development and the climate issue have been dealt with over time. As a consequence, they have faced a number of challenges regarding their production process, and they constantly ask themselves the question ”What is sustainable after all?”. Cooperation with subcontractors is long-term and important, and the preservation of crafts is the main focus. Manufacturing processes and selection of materials are carefully evaluated – There is a thought behind every decision.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Vilka nya marknadsmodeller kan få producerande företag att gå mot cirkulär ekonomi?2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

Environmental awareness in the world is increasing. The social debate is increasingly formed by an environmental perspective on several fronts. More and more people are beginning to understand that the earth's resources are finite and we must think about how we live today. The producing industry accounts for a large part of the use of raw materials, but how will the industry change in the future?

The industry of the future is often described as a circular economy where minimal amounts of raw materials are broken and the majority of the material that is in use goes back to production. The reality we live in today is another, the greater part of the world's industry continues with linear production where raw materials are used in manufacturing and products are deposited at the end of its lifecycle. The project group examines the building blocks of circular economy and where we are today in the development towards sustainable management of raw materials.

The purpose of the report is to investigate the economic advantages for companies to change to circular economy in the form of new business models. Opportunities for these business models often grow with the help of new technology from Industry 4.0 like Internet of Things and Big Data.

We have the conclusion that business models such as pay-per-use where companies maintain ownership of the product, often are easy to implement in circular economics, since the company itself can control the entire circuit for the product. They make it easier to base their production on return of products if they control the volumes of the returned products themself. These models are often based on selling services that are dependent on the Internet of things and Big Data.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Vilka metoder och mätetal som företag använder sig av för att utveckla sin befintliga resurseffektivitet2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

As a consequence of the rapid technology development around the world, large manufacturing companies in Sweden face great challenges in order to keep up with development, and to compete with others. Achieving a resource-efficient production is one of the biggest challenges that companies strive to achieve.

The purpose of this thesis is to answer the question "What methods and measures is used by companies to develop their existing resource efficiency?” It was done by first making a broad research about the particular subject in order to find scientific articles and thereafter all the information was narrowed down. In addition, two case studies was executed at Scania and Octapharma to investigate what types of methods and measures they use. The results of the interviews at the two companies were to be compared with the findings in the scientific articles to see how they complete each other.

The thesis provided the following results: The different parts within Lean is practiced as methods in order to achieve a resource-efficient production in the companies that were interviewed and in the selected scientific articles. There is a correlation between the size of a company and its ability to fully implement Lean. A larger company is usually able to implement Lean to a larger extent than a smaller one. OEE and OPE are two measures that were used by Scania, while Octapharma did not use any measures because they measure the efficiency manually. Moreover, communication is a necessary factor in order to achieve a efficient production. The size of the company has an impact on the level of the communication as well. A larger company has a better overall structure and puts in more time and resources to make the communication as effective as possible.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Hur används operatörens kunskap och kompetens för utveckling av produktionen?2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

An important part of the Lean production system is the elimination of waste of various kinds. One of these wastes is unused creativity and competence, which was also the basis for this report and we landed in the issue "How is the operator’s knowledge and competence handled in development of the production?". The work is based on a literature study of knowledge management and Lean principles, as well as interviews with an operator and production manager at Scania and Sandvik Coromant.

Theory shows that there are a variety of ways to look at knowledge and how it is handled in the best possible way. This theoretical subject is called knowledge management and discusses different ways of approaching knowledge transfer and management in business. The subject is based on the fact that there are two ways of looking at knowledge, as an object or as a process linked to action. There is also two kinds of knowledge, explicit which is concrete knowledge such as an instruction and implicit knowledge which is personal knowledge and often comes from experience.

Both Scania and Sandvik Coromant are currently incredibly proficient in knowledge transfer and working with Lean, which is evident through their well established methods and systems. They both have a great focus on improvements and let no deviations pass without discussion. Employees are highly involved in the companies and are given opportunities to influence and develop their workplace. Scania and Sandvik Coromant use different methods to attempt to gather and save implicit knowledge from their experienced employees, but it is a challenge.

The analysis shows that the knowledge management depends on many different parts of the production. In summary it is about the understanding of knowledge, good leadership, well functioning teams and the usage of knowledge management tools. The knowledge that the companies manages to capture is currently used to improve the working environment and safety, but also to develop the companies and keeping them competitive.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Lean Production System: En redogörelse av resurseffektiv produktion och hur det implementeras inom Scania2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

The purpose of this work is to gain a better understanding of what Lean Production entails, with its basic foundations such as the Toyota Production System (TPS), and how it is implemented practically in the industry, where the theory behind Lean Production is put into operation. Lean Production is a philosophy in which you work to achieve as resourceefficient production as possible, by among other things reducing various forms of waste.

To limit the scope of the work, Scania's engine department is specifically investigated and how their implementation of Lean Production and interpretation of the Toyota Production System looks. The work was carried out both as a literature study, with scientific sources from KTH's database and literature within Lean Production and Toyota Production, and field study in the form of an interview with an employee in the engine department at Scania, a tour of the production and a lecture on the Scania Production System.

Toyota is the founder of the Toyota Production System, where they developed a unique system that gives results in terms of quality and efficiency. From being a small company, they were developed into the world's largest car manufacturer and are one of the main reasons why Lean and TPS were noticed. Toyota has 14 principles that address their philosophy, people, processes and problem solving, where these principles are of benefitial to companies seeking to develop their business, both in service and manufacturing. Lean Production is a philosophy that originates from TPS, where it mainly focuses on eliminating seven different types of waste and instead adding more value to the customer.

The result of this work has generated an overall picture of what Lean Production and its foundations are and how it has been implemented in Scania's engine department, where they developed their own production system SPS, the modular system and individual management. In the SPS, many of the concepts discussed in TPS and Lean Production are found and are also the main similarity between these three production systems. What distinguishes Scania from TPS and Lean Production is primarily individual management and the modular thinking.

The conclusion is that Scania is better adapted to Lean than we previously thought and that their work fits well with what Lean Production is today.

• KTH, School of Electrical Engineering and Computer Science (EECS).
Holistic Sustainability Transformation & Addressing Impacts on Global Biodiversity Integrity: Incumbent Nordic Media Companies2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis

Growing ecological challenges [1][2][3] can be addressed by the media industry through proactive engagement with holistic sustainability transformation that covers all activities within their value-chain. With at least 60% of vertebrate species already lost [1] and 40% of insect species at risk of the same [2], the time for business-as-usual has past [4][5][6][49]. In order to mitigate negative, and accelerate positive, impacts on global biodiversity integrity, media companies need to look beyond direct impacts, carbon, and segmented actions to a more holistic understanding and approach of sustainability transformation.

This study focused specifically on the Nordic region (Sweden, Norway, Denmark, Finland) and the largest incumbent companies within that region (Schibsted, MTG, Bonnier, Egmont and Sanoma) [7][8], to find what actions and pathway are necessary to protect both people and planet [10]. Through understanding the drivers of biodiversity loss, as well as the proposed sustainability transformation roadmaps from the research community, and by quantitatively analyzing how these five companies understand and prioritize sustainability, this study developed a visual Pathway Lens consisting of Seven Focus Areas (SFAs) to enable media companies to look holistically at their activities and value-chain. The SFAs need to be approached holistically, similar to the 17 SDGs (Agenda 2030) [4].

Since incumbent Nordic media companies are not currently looking at impacts on biodiversity integrity, nor focusing on a holistic approach to sustainability, the SFAs of the Pathway Lens are a tool to better understand their unique opportunity to accelerate sustainable lifestyles through their content, marketplaces, products and events, which in turn address impacts on biodiversity integrity. The media industry also shares in the collective opportunity to accelerate sustainable value-chains through prioritizing self-transcendence values, resources, responsible operations, circular business models, iterative stakeholder engagement, and external partnerships. Since the drivers of biodiversity loss are complex and interconnected [3], protecting both people and planet requires complex and interconnected solutions.

• KTH, School of Electrical Engineering and Computer Science (EECS).
KTH, School of Electrical Engineering and Computer Science (EECS).
Stuck state avoidance through PID estimation training of Q-learning agent2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

Reinforcement learning is conceptually based on an agent learning through interaction with its environment. This trial-and-error learning method makes the process prone to situations in which the agent is stuck in a dead-end, from which it cannot keep learning. This thesis studies a method to diminish the risk that a wheeled inverted pendulum, or WIP, falls over during training by having a Qlearning based agent estimate a PID controller before training it on the balance problem. We show that our approach is equally stable compared to a Q-learning agent without estimation training, while having the WIP falling over less than half the number of times during training. Both agents succeeds in balancing the WIP for a full hour in repeated tests.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Resurseffektivisering för ökad lönsamhet inom tryck & förpackning2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

To be well prepared for the competitive market in commercial printing, today's companies must direct their production towards becoming more resource-efficient and profitable. It is known that the current market requires ever-increasing production capacity, but the customer is willing to pay less for the products. It is therefore critical that a company keep its productivity high and eliminate unnecessary losses in the production.

The purpose of this thesis is to investigate how resource efficiency affects the profitability of a company. The concept of key figures will be introduced and used primarily to measure and study profitability for a printing company. The project's work takes place in two phases. At first, a literature study, which is used to identify the most important key figures and study how they can be related to resource efficiency and profitability. The second phase involves a field study carried out at Eson Pac Ljungberg, a printing company that produces pharmaceutical packaging. The goal is to locate the largest assets and how they should be managed to extract the greatest possible profitability.

There are many ways to measure and benchmark the performance of a production line. Today's technology provides opportunities to perform complex measurements using computer sensors and telecommunication equipment. However, the challenge is to apply these metrics and use them in practical implementation. All employees in the company must take part in these measurements and understand how they can be used to improve production. These metrics are turned into key figures when a company has successfully found a method of merging its production strategy with the metrics. The method is based on choosing the most relevant metric, considering the company's objectives. the company will then set up an effective communication channel where the management and manufacturers can quickly exchange information about the production and feedback quickly when errors and changes occur.

The result shows that the main resources that contribute to increased profitability are materials, equipment and personnel. By compiling the key figures and an example measurement of OEE value (Overall Equipment Effectiveness), it is shown that low utilization of resources can have negative consequences for profitability. Field study at Eson Pac AB shows that the company's management has an active list of key figures and objectives that they are constantly working towards. The company, on the other hand, shows deficiencies in following up their key figures, since communication between management and production staff lacks mutual understanding of each other's tasks and many of the key figures are not used to their full potential. Eson Pac AB formulates its key figures mainly according to the customer's perception, unlike the versatile factors of the literature study. Customer relationship seems to be the company's focus and has a great impact on the company's view of resource access. The two key figures that the company agrees with the literature review are delivery precision and customer complaints, i.e. the two main key figures to indicate customer satisfaction.

• KTH, School of Industrial Engineering and Management (ITM).
KTH, School of Industrial Engineering and Management (ITM).
Making production more efficient through modernisation and increased automatization.: A case study at a potato production line2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis

As labour prices are rising, and automation gets more advanced, it is important for all process industries to get involved with automation to be able to survive on the open market. Large companies in the process industry have been dealing with automation for decades, thereby making the technology more available and affordable. Smaller companies might not have had the financial strength to invest in such technology in the past, but as the equipment needed becomes more user friendly and affordable, the time for smaller companies to invest in automated systems has come. The cost of buying new automated equipment is high, but the systems in use might not be outdated if machine control and monitoring are modernized.

Process technology has in many cases not been changed radically over the last decades, so modernizing of older equipment might be a more affordable way to automize production. In this report, installation and testing of both modernizing and used equipment has been done, and the results are quite convincing. Labour costs are reduced by investing a fraction of the cost compared to new equipment. The modernized machines might not be as future proof as newer machines, but it gives companies without the financial strength to invest in new machines the possibility to compete with modern automated production lines.

We took a close study at a potato production line at Glomma Potetpakkeri AS, where we installed and tested a robot palletizer. We also discussed possible upgrades with the manager at the plant and calculated some profitability of the possible investments.

A conclusion has been made, and in our perspective, a reasonable amount of automation can be achieved without large investments, and the market for these services do exist.