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  • Flodin, Martin
    KTH, School of Computer Science and Communication (CSC).
    Betydelsen av skuggning vid volymrenderad visualisering i en multimodal simulator för operativ extraktion av visdomständer2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this thesis was to investigate the importance shading has on the perception of depth in a multimodal simulator for operative extraction of wisdom teeth. The simulator uses both haptics and stereo graphics to convey information about depth. The problem formulated in the thesis was to investigate the necessity of using shading, which is quite demanding computationally, or if a simpler type of rendering would suffice.

    User tests have been performed with experienced dentists who have tried different graphical renderings of the same patient case in the simulator. The method used for the tests is called cooperative evaluation and allows for discussions between the user and the evaluator.

    Shading turns out to play an important role in the users’ perception of depth. It even seems to be more important than the stereo information since the area the dentists focus on is so small the stereo effect seems negligible. The fact that not all people can see depth in stereo images is also important to consider.

    As the intended users are relatively young dental students, they are accustomed to almost photorealistic graphics in computer games and computer animation. Therefore the graphics in the simulator needs to be as close to that standard as possible.

    The use of haptics does make it possible for the user to feel where s/he is located depthwise, but when a conflict with the visual feedback occurs, the visual information tends to dominate.

    The conclusion therefore is to recommend that shading definitely is worth implementing, even though it requires additional resources.

  • Jonsson, Martina
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Exploring Designs for Enhancing the In-store Customer Experience through Digital Product Information in Fashion Retail2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The ongoing consumer transition from offline to online shopping in the fashion retail industry requires retailers to take action. Not only do consumers shop more online, they also go online for research of retail products. Forecasts tell that bringing the online experience to offline stores might bridge the gap between the two channels. The online experience provides high-end digital content, and puts a demand on the product information offline as this was found crucial for the customer experience. The marketing possibilities in-store was found to be an advantage to bricks-and-mortar retailers. Thus, this study aims to investigate how the customer experience can be enhanced in retail bricks-and-mortar stores through digital product information. A survey was conducted to identify user requirements in terms of product information. An augmented reality prototype was formed to satisfy the identified user requirements. The prototype was tested in two user studies that evaluated the content, visualization, interaction and satisfaction. The prototype was iterated between the two user studies. The most crucial parameters of fashion retail product information were established, together with implications for the visual representation and interaction. It was found that there were unfulfilled user needs with existing service options, which were satisfied with the use of an augmented reality prototype for product information retrieval. The use of AR for this purpose also proved to be able to contribute to an omnichannel solution for multi-channel retailers. The conclusion was thus that the customer in-store experience could be enhanced by the introduction of an augmented reality prototype for product information retrieval, taking into account the implications for content, visualization and interaction provided in this study.

  • Möller, Josefine
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Actions for Increasing an Organization’s UX Maturity2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    User experience (UX) design is becoming increasingly crucial for developing successful software today. It can determine whether or not users stay engaged with a product or service and it can also affect the time spent completing tasks which can make a large difference to employees when they try to get their job done. It is therefore important that organizations have their users in mind when developing software and that there is a maturity for UX and user-centered work. Since there are organizations where UX is not highly valued and where the maturity for UX is low it is interesting to find out what can be done to increase the UX work within these organizations, which was the aim of this thesis. The problem was addressed by studying a specific organization that expressed difficulty getting UX work to fit in their working routines, partly due to the fact that they were also working with agile software development. The organization’s maturity for UX was evaluated using Nielsen’s UX maturity model which is a model that describes eight different stages of UX maturity. Data was collected through a survey where questions were based on the UX maturity model and was then followed up with five semi-structured interviews. The results showed that the highest level of maturity yet reached within the organization was stage four, where there is a budget and plan for UX in some projects and where some teams have defined UX roles. A lower level of maturity could also be identified for some teams. Based on these findings, actions for how the organization can increase their UX maturity were discussed. These actions were concluded to be: plan for UX, find a way to show UX results, meet with real users, have UX professionals lead the way and structure UX work to fit with agile processes.

  • Ståhlberg, Louise
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    MusiCushions: Designing interactive cushions that integrate with the home environment2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper is about MusiCushions: Interactive cushions to control external speakers in a living room. The interactive cushions are made of smart and interactive textiles, which acceptance has been profoundly investigated. Several studies have come to the conclusion that the most important feature for acceptance of smart and interactive textiles is the aesthetics of the textile interface. Therefore, this study investigates the question: How is integration of interactive cushions in the home environment affected by design concepts with different levels of explicit interaction and types of use cues? The method used in this study is based on constructive design research (CDR), where the design process consisted of moodboarding, sketching, prototyping and evaluation. Three prototypes were built and tested in two different user observations. The interactive cushions were considered well integrated in the home environment but there is room for improvement of usability. The evaluation showed that visual cues were the most important feature for usability but that there is a trade off between use cues and aesthetics.

  • Sterner, Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Multicomponent fractionation of Saccharina latissima brown algae using chelating salt solutions2016In: Journal of Applied Phycology, ISSN 0921-8971, E-ISSN 1573-5176, Vol. 28, no 4, p. 2561-2574Article in journal (Refereed)
    Abstract [en]

    A fractionation strategy for Saccharina latissima algal biomass was developed utilizing chelating extraction salt solutions to mediate the liberation of algal components. Alginate, cellulose, laminarin, mannitol, protein, and inorganic salts were quantified in the fractions to reveal their individual dissolution patterns. Chelation power was identified as a key parameter for liberating alginate and increasing the yield of extracted components. The most efficient fractionation was achieved using aqueous sodium citrate as the extraction solution, producing an alginate-rich soluble fraction and a salt-poor insoluble fraction rich in cellulose and protein. Extractions at decreased pH were shown to be beneficial because they decreased the M/G ratio of the extracted alginate and concentrated the protein in the insoluble fraction from which it can easily be recovered; these effects could be achieved by switching the traditional sodium carbonate extraction solution with salts that have chelation capacity at lower pH. A cyclic extraction demonstrated that the sodium citrate solution can be reused for multiple alginate extractions with the buildup of the concentrations of other valuable components in the solution.

  • Latupeirissa, Adrian
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    MusiCushions: Prototyping an E-Textile Interface for Music Interaction in Home Environment2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper presents MusiCushions, a set of interactive sofa cushions used as an interface to music. Built on physical affordances of sofa cushions and e-textile technology, the artefact is used to explore how an e-textile interface can be used for music interaction at home. Challenges in prototyping e-textile interfaces would also be identified. Three cushions are prototyped with off-the-shelf e-textile and electronic components: in one cushion, its case is explored as an interactive surface; another cushion explores the softness and how it can be easily pressed; and the last cushion explores its portability. The set is then mapped to music interaction in two scenarios: as a remote control to a music player and as a musical instrument to control a synthesizer. Evaluation is conducted in two focus group discussions involving students in Media Technology. It is concluded that MusiCushions could be received as a new way to control media such as music player at home, with broader possible use to interact with other services and objects. As a musical instrument, however, it might not be accepted due to the lack of precision control.

  • Yang, Yanpeng
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Hossein, Shokri-Ghadikolaei
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Fischione, Carlo
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Ki Won, Sung
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Fast and Reliable Initial Access with Random Beamforming for mmWave NetworksManuscript (preprint) (Other academic)
    Abstract [en]

    Millimeter-wave (mmWave) communications rely on directional transmissions to overcome severe path loss. Nevertheless, the use of narrow beams complicates the initial access procedure and increase the latency as the transmitter and receiver beams should be aligned for a proper link establishment. In this paper, we investigate the feasibility of random beamforming for the cell-search phase of initial access. We develop a stochastic geometry framework to analyze the performance in terms of detection failure probability and expected latency of initial access as well as total data transmission. Meanwhile, we compare our scheme with the widely used exhaustive search and iterative search schemes, in both control plane and data plane. Numerical results show that, compared to the other two schemes, random beamforming can substantially reduce the latency of initial access with comparable failure probability in dense networks. We show that the gain of the random beamforming is more prominent in light traffics and low-latency services. Our work demonstrates that developing complex cell-discovery algorithms may be unnecessary in dense mmWave networks and thus shed new lights on mmWave network design.

  • Marang, Ah Zau
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Analysis of web performance optimization and its impact on user experience2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    User experience (UX) is one of the most popular subjects in the industry nowadays and plays a significant role in the business success. As the growth of a business depends on customers, it is essential to emphasize on the UX that can help to enhance customer satisfaction. There has been statements that the overall end-user experience is to a great extent influenced by page load time, and that UX is primarily associated with performance of applications. This paper analyzes the effectiveness of performance optimization techniques and their impact on user experience. Principally, the web performance optimization techniques used in this study were caching data, fewer HTTP requests, Web Workers and prioritizing content. A profiling method Manual Logging was utilized to measure performance improvements. A UX survey consists of User Experience Questionnaire (UEQ) and three qualitative questions, was conducted for UX testing before and after performance improvements. Quantitative and qualitative methods were used to analyze collected data. Implementations and experiments in this study are based on an existing tool, a web-based application. Evaluation results show an improvement of 45% on app load time, but no significant impact on the user experience after performance optimizations, which entails that web performance does not really matter for the user experience. Limitation of the performance techniques and other factors that influence the performance were found during the study.

  • Dabbaghchian, Saeed
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Computational Modeling of the Vocal Tract: Applications to Speech Production2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Human speech production is a complex process, involving neuromuscular control signals, the effects of articulators' biomechanical properties and acoustic wave propagation in a vocal tract tube of intricate shape. Modeling these phenomena may play an important role in advancing our understanding of the involved mechanisms, and may also have future medical applications, e.g., guiding doctors in diagnosing, treatment planning, and surgery prediction of related disorders, ranging from oral cancer, cleft palate, obstructive sleep apnea, dysphagia, etc.

    A more complete understanding requires models that are as truthful representations as possible of the phenomena. Due to the complexity of such modeling, simplifications have nevertheless been used extensively in speech production research: phonetic descriptors (such as the position and degree of the most constricted part of the vocal tract) are used as control signals, the articulators are represented as two-dimensional geometrical models, the vocal tract is considered as a smooth tube and plane wave propagation is assumed, etc.

    This thesis aims at firstly investigating the consequences of such simplifications, and secondly at contributing to establishing unified modeling of the speech production process, by connecting three-dimensional biomechanical modeling of the upper airway with three-dimensional acoustic simulations. The investigation on simplifying assumptions demonstrated the influence of vocal tract geometry features — such as shape representation, bending and lip shape — on its acoustic characteristics, and that the type of modeling — geometrical or biomechanical — affects the spatial trajectories of the articulators, as well as the transition of formant frequencies in the spectrogram.

    The unification of biomechanical and acoustic modeling in three-dimensions allows to realistically control the acoustic output of dynamic sounds, such as vowel-vowel utterances, by contraction of relevant muscles. This moves and shapes the speech articulators that in turn dene the vocal tract tube in which the wave propagation occurs. The main contribution of the thesis in this line of work is a novel and complex method that automatically reconstructs the shape of the vocal tract from the biomechanical model. This step is essential to link biomechanical and acoustic simulations, since the vocal tract, which anatomically is a cavity enclosed by different structures, is only implicitly defined in a biomechanical model constituted of several distinct articulators.

  • Rudqwist, Lucas
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Designing an interface for a teleoperated vehicle which uses two cameras for navigation.2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish fire department have been wanting a robot that can be sent to situations where it’s too dangerous to send in firefighters. A teleoperated vehicle is being developed for exactly this purpose. This thesis has its base in research that previously has been conducted within Human-Robot Interaction and interface design for teleoperated vehicles. In this study, a prototype was developed to be able to simulate the experience of driving a teleoperated vehicle. It visualised the intended interface of the operator and simulated the operating experience. The development followed a User-Centered Design process and was evaluated by users. After the final evaluation a design proposal, based on previous research and user feedback, was presented. The study discusses the issues discovered when designing an interface for a teleoperated vehicle that uses two cameras for maneuvering. One challenge was how to fully utilize the two video feeds and create an interplay between them. The evaluations showed that users could keep better focus with one larger, designated main feed and the second one being placed where it can be easily glanced at. Simplicity and were to display sensor data were also shown to be important aspects to consider when trying to lower the mental load on the operator. Further modifications to the vehicle and the interface has to be made to increase the operators awareness and confidence when maneuvering the vehicle.

  • Li, Qianqian
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Pilot-scale plant application of membrane aerated biofilm reactor (MABR) technology in wastewater treatment2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This membrane aerated biofilm reactor (MABR) pilot project was performed at Ekeby wastewater treatment plant (WWTP) in Eskilstuna, Sweden. This plant is facing a future challenge of effluent TN < 10mg/L according to the new standard and the growing population, where higher treatment capacity is needed. The MABR as a newly invented technology, is chosen as a promising countermeasure towards the challenge, because of the simultaneous nitrification and denitrification of this technology. By the time of reporting, this project is still on-going, and more information will be reported later in separate report.

    The feed water comes from the secondary clarifier of full-scale plant. Dissolved oxygen (DO), processing air and flow rate was manually controlled to test different operational settings. However, there were a lot challenges during the testing period which makes it hard to evaluate the performance of this pilot. The ammonium removal efficiency is satisfying when the pilot was running smoothly. However, the TN removal efficiency did not comply with the expectation, achieved in average of 39,01%, due to the limitation of readily bio-degradable COD (rbCOD), which is a limitation of the biological process in general and is not specific to MABR.

    This technology is considered as promising by the end of the current testing period, since it can oxidize the ammonium effectively with smaller volume.

  • Patch, Hanna
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Which factors influence Generation Z’s content selection in OTT TV?: A Case Study2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As digital technologies rapidly evolve, traditional television is being disrupted by the development of more devices, screens, and content. Over-the-top television [OTT TV] is replacing linear TV at a growing rate. A majority of consumers of over-the-top content are found in the generational cohort, Generation Z. As true digital natives, this generation is comfortable navigating a variety of online TV platforms and devices, while also being more susceptible to short attention-span and information overload. It is therefore necessary to understand how this emerging cohort makes choices in a TV landscape that is becoming increasingly overloaded with new content.

    The purpose of this study is to understand which user interface components Generation Z takes into consideration when selecting content in OTT TV. Multiple methodologies were selected to investigate these media habits. Think-aloud usability testing and interview determined Generation Z’s natural media behavior while browsing OTT content. Online survey data was collected from a broader sample, comparing Generation Z and Generation Y. It was discovered that both generations have similar behaviors in which user interface components influence content choice. The research also revealed trends in which components are important to Generation Z and why. This research is the first step to making informed and data-driven decisions in the design and implementation of OTT TV platforms for Generation Z, thus lessening cognitive overload and creating optimal user experiences. 

  • Nowik, Martyna
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Promoting Digital Transformation in Digitally Developing Industries: A case study on strategic action points driving digital transformation in the real estate industry2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The digital transformation of businesses has come a long way; however, research and reports are showing how some industries has fallen behind in the progress. This research aimed at identifying driving factors that are essential in the progression of digitalization and use of digital capabilities. The central research question was as follows: What strategic action points should businesses within the real estate industry adopt individually and together in order to support a steady development towards becoming a digitally dextrous industry? The research was performed as a case study, using the real estate industry as an example. The case study consisted of 8 semi structured interviews, performed with representatives of various companies from the real estate value chain. Using Soule et. al.s (2016) M-PWR model as an analytical foundation, three action points, essential for businesses in digitally laggarding industries, were defined: 1. Reforming the organizational structure for better agility and empowerment of the workforce. 2. Create channels and methods encouraging collaborations between various actors. 3. Develop structured processes for identifying, extracting and managing available resources. 

  • Björklund, Linnea
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, perception and learning, RPL.
    Knock on Wood: Does Material Choice Change the Social Perception of Robots?2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper aims to understand whether there is a difference in how socially interactive robots are perceived based on the material they are constructed out of. Two studies to that end were performed; a pilot in a live setting and a main one online. Participants were asked to rate three versions of the same robot design, one built out of wood, one out of plastic, and one covered in fur. This was then used in two studies to ascertain the participants perception of competence, warmth, and discomfort and the differences between the three materials. Statistically significant differences were found between the materials regarding the perception of warmth and discomfort

  • Berg, Niclas
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Blood flow and cell transport in arteries and medical assist devices2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The cardiovascular system is responsible for transport of nutrients, oxygen, as well as the cells and molecules making up the immune system. Through the hemostatic system, the body maintains the integrity of the blood vessels, and prevents bleeding. The biochemical and physical processes governing the circulation interact, and take place at a large range of time and length scales - from those related to the individual cells up to the large scale flow structures. Dysfunctions of the heart or the circulatory system may have severe consequences. Cardiovascular diseases (CVD) is a heterogeneous group of diseases, responsible for about 50% of all death cases in the western world.

    Patients with severe but transient heart and/or lung disease may require the assistance of a heart-lung machine to bridge over the period required for the affected organ to recover. One such system is the Extracorporeal Membrane Oxygenator (ECMO) circuit, consting of a blood pump, a membrane oxygenator, cannulae and tubing system. While the therapy is life-saving, it is associated with relatively frequent thromboembolic (blood clotting and/or bleeding) events. Modeling of the flow in some components of the ECMO circuit was undertaken. The flow data was used together with models for platelet activation to assess the risk for thrombus formation. The results indicated locations of elevated risk of thrombosis in the centrifugal blood pump, the ECMO cannulae and the pipe connectors. The identified locations agreed well with clinical observations. The results lead to a direct recommendation to minimize the use of tube connectors. Further study of the sensitivity of the platelet activation models to uncertainties and errors was carried out. Some recommendations for improved modeling were proposed.

    Arteriosclerosis develops slowly over a long period of time (years or decades). It manifests initially at some common sites; arteries of certain sizes with relatively strong flow rate, as well as near artery bifurcations and locations of strong vessel curvature. The location specificity indicates that the blood flow plays a central role in the arteriosclerotic process. Being able to predict the future development of arteriosclerotic lesion and its location for an individual patient would imply that pre-emptive actions could be taken. This idea was the foundation of some of the numerical simulations in this thesis. A stenoted patient specific renal artery was considered, and was reconstructed to a non-pathological state by removing the stenosis using different segmentation methods. We could then evaluate if common stenosis markers based on functions of time-averages of the Wall Shear-Stress (WSS) could be use as predictive parameters. It was shown that these markers are not adequate as predictive tools. Furthermore, it was shown that the sensitivity to reconstruction technique was at least of the same order as the effect of the choice of blood rheology model. The rheology of blood was further studied through detailed simulations resolving the blood plasma flow and its interaction with the red blood cells (RBC) and the platelets. A hybrid Immersed boundary-Lattice Boltzmann method was applied, and the rheological data was compared to the Quemada model. It was found that the Quemada model could underpredict the effective viscosity by as much as 50%. The same methodology was applied to study the transport of RBCs and platelets, and the influence of RBC polydispersity. An increased degree of variability in RBC volume was found, under certain circumstances, to lead to an increase of the transport of platelets to the vessel wall (margination). 

  • Tahar Aissa, Safia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Improving well-being with virtual reality for frail elderly people: a mixed method approach letting them into the three-dimensional world2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]


    The Swedish population is ageing – resulting in an increase in the number of elderly people and higher socioeconomic demands that the society needs to support them with. In Sweden, frail elderly people with for example mobility and cognitive problems, have the opportunity to attend a day care center where they can join activities and to socialize.


    The purpose of this thesis was to investigate to what extent virtual reality technology could contribute to improved well-being for frail elderly at day care centers.


    This study was conducted via a mixed method consisting of a survey and a semi-structured interview. 19 participants (15 male and 4 female) from three day care centers in Södertälje participated in this study.


    By allowing frail elderly at day care centers to experience virtual reality, quantitative and qualitative data was collected. Both indicating that the experience of using virtual reality was positive and comfortable. 7 themes were identified through a thematic analysis demonstrating what was repeatedly mentioned by the participants. The themes were: (1) immersion & interaction, (2) usage, (3) nature movies, (4) visit places, (5) talking about things that are dear to them, (6) being limited and (7) thinking that VR could affect well-being.


    This study showed that the subjective well-being of frail elderly was arguably partially improved with virtual reality. The participants were overall positive, enjoyed the experience with a sense of immersion and awakening memories. 

  • Sigurjonsson, Sindri Már Kaldal
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Blockchain Use for Data Provenance in Scientific Workflow2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In Scientific workflows, data provenance plays a big part. Through data provenance, the execution of the workflow is documented and information about the data pieces involved are stored. This can be used to reproduce scientific experiments or to proof how the results from the workflow came to be. It is therefore vital that the provenance data that is stored in the provenance database is always synchronized with its corresponding workflow, to verify that the provenance database has not been tampered with. The blockchain technology has been gaining a lot of attention in recent years since Satoshi Nakamoto released his Bitcoin paper in 2009. The blockchain technology consists of a peer-to-peer network where an append-only ledger is stored and replicated across a peer-to-peer network and offers high tamper-resistance through its consensus protocols. In this thesis, the option of whether the blockchain technology is a suitable solution for synchronizing workflow with its provenance data was explored. A system that generates a workflow, based on a definition written in a Domain Specific Language, was extended to utilize the blockchain technology to synchronize the workflow itself and its results. Furthermore, the InterPlanetary File System was utilized to assist with the versioning of individual executions of the workflow. The InterPlanetary File System provided the functionality of comparing individual workflows executions in more detail and to discover how they differ. The solution was analyzed with respect to the 21 CFR Part 11 regulations imposed by the FDA in order to see how it could assist with fulfilling the requirements of the regulations.  Analysis on the system shows that the blockchain extension can be used to verify if the synchronization between a workflow and its results has been tampered with. Experiments revealed that the size of the workflow did not have a significant effect on the execution time of the extension. Additionally, the proposed solution offers a constant cost in digital currency regardless of the workflow. However, even though the extension shows some promise of assisting with fulfilling the requirements of the 21 CFR Part 11 regulations, analysis revealed that the extension does not fully comply with it due to the complexity of the regulations

  • Övermark, Timo
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Assessment of Coverage and Effect of Web Content Accessibility Guidelines 2.12018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Web Content Accessibility Guidelines (WCAG) are an important resource for making the web more accessible for people with disabil- ities. They are used as a source of information for web content cre- ators, but also in standards as a basis for legislation when measuring whether a website is accessible or not. The guidelines have been criti- cized for poor coverage when studying real-life accessibility, especially for people with cognitive impairments. A newly released version of the guidelines, WCAG 2.1 aims to improve accessibility but has not been studied yet.

    This study evaluates the coverage of WCAG guidelines by con- ducting a user study and comparing the results with WCAG evalu- ation to find out if the problems found by users would be fixed by conforming to the guidelines. 3 websites were evaluated with a total of 6 users from 3 different disability groups. Same sites were evaluated with WCAG 2.0 and 2.1.

    The results show none of the site passed the WCAG evaluation. The users found 40 issues, of which 32,5% would be fixed if conform- ing to WCAG criteria. Most of the issues not covered by WCAG were related to understandability and readability of the content and the user interface. The blind group found the biggest number of issues, but al- most half of the issues would be fixed by WCAG, compared to only 13% for people with cognitive impairments. Despite the fact that all critical issues were covered by WCAG, the amount of serious issues not covered reveals that WCAG as a sole measure for accessibility is not enough to guarantee equal access to the web.

  • Kryściński, Wojciech
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Training Neural Models for Abstractive Text Summarization2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abstractive text summarization aims to condense long textual documents into a short, human-readable form while preserving the most important information from the source document. A common approach to training summarization models is by using maximum likelihood estimation with the teacher forcing strategy. Despite its popularity, this method has been shown to yield models with suboptimal performance at inference time. This work examines how using alternative, task-specific training signals affects the performance of summarization models. Two novel training signals are proposed and evaluated as part of this work. One, a novelty metric, measuring the overlap between n-grams in the summary and the summarized article. The other, utilizing a discriminator model to distinguish human-written summaries from generated ones on a word-level basis. Empirical results show that using the mentioned metrics as rewards for policy gradient training yields significant performance gains measured by ROUGE scores, novelty scores and human evaluation.

  • Shi, Shuai
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering.
    Antenna Limitations and Q-factor Trade-off between Parameters, Steps towards Optimal Antenna Design2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sub-wavelength antennas have become ubiquitous in essential devices, such as mobile phones, sensors, Internet of things (IoT) and machine to machine (M2M) communication devices. Such antennas are often embedded as a small part of the device chassis or their circuit-boards. The size assigned both to the antennas as well as the device tends to shrink, while demands on antenna performance are increasing. In such a context knowledge of optimal performance is of increasing importance. The subject of this thesis is on the bounds of small antennas, in particular bounds on impedance bandwidth performance.

    The main tool to obtain bounds is antenna current optimization. The bounds are mainly focused on determining limits on the Q-factor for small antennas, and hence implicitly on the available bandwidth at a given reflection coefficient. We investigate Q-factor bounds under a number of constraints including directivity, far-field radiation pattern, efficiency, and the embedded position of the antenna. In this process, we combine physical methods, mathematical tools, and antenna engineering. We use the Method of Moments (MoM) approach to solving the Electric Field Integral Equations (EFIE), in this context we formulate and solve antenna optimization problems where the surface current density is an unknown variable, and we solve convex and non-convex quadratically constrained quadratic programs (QCQPs). For non-convex problems, we investigate different methods to obtain the solution, but with the main focus on the semidefinite relaxation (SDR) technique. Different current optimization problems are solved for a range of shapes, where the Q-factor and the optimal surface current are determined; the results are compared with full-wave-simulation of antennas that approach the bounds.

    To determine the Q-factor for an available space in the device is here proposed to be an initial step of an antenna design procedure. The current optimization helps us to determine the optimal trade-off between the different performance parameters of a small antenna, and it can inspire antenna design with better performance. We furthermore show that a multi-position feeding strategy to realize an optimal current successfully realize a non-standard far-field performance. As an example, we show that the desired radiation patterns are obtained with small costs of Q-factor. The thesis ends with a discussion of initial steps to a methodology with the goal of obtaining a Q-factor optimal antenna. Here the current optimization plays an important role in the antenna synthesis and analysis stages of the process. An application to the embedded antenna is discussed in detail.

  • Neppare, Christoffer
    KTH, School of Electrical Engineering and Computer Science (EECS).
    A Force Directed Graph for Visualization of Voters Preferences Relative to Political Parties2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As conversations in society to a larger extent are carried out on the internet, so are the civic conversations that are the basis of the democratic process. To help citizens better navigate the democratic process, several news agencies in Sweden provide a version of Valkompassen, the election compass. The intent behind Valkompassen is to give the normal reader an easily understood answer for which party they are most aligned with on 25 questions relevant for the election. This paper suggests an alternative information visualization based on a force directed graph of the results from Valkompassen (developed by TT Nyhetsbyrån). The affordances of a force-directed graph make it an interesting option due to its ability to display specific questions in an intuitive way and aesthetically pleasing way on a two or three dimensional plane not restricted to a political left-right axis. The results of this study suggest that the average citizen might not be familiar with the force directed graph as an information visualization tool but that they felt confident in using it after a few minutes of interaction. Most participants in the study did experience seeing their political sympathies spread across the political left-right divide and found the graph informative for exploring individual questions. The report did not however find that the alternative graph replaced the original Valkompassen in experience provided. The discussion contains some recommendations for how to facilitate the learning curve and proposals for how the artifact could better make use of the affordances of the force-directed graph in the future.

  • de Groot, Jan Jaap
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Designing a system for visually impaired users to identify objects2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the process of designing a system for visually impaired users to identify objects. Smartphones are empowering visually impaired people by providing independence. The two major mobile operating systems, Android and iOS, both include screen reading software. By enabling this feature, the content of the screen is read out loud and the way of interaction is changed. These screen readers have been further investigated to optimize the user experience. Furthermore, several options for identifying objects have been explored. The system has been evaluated by over a hundred blind and visually impaired users. This thesis presents how the design of the system was iteratively improved and in which way it is now being used.

  • Marcon, Nicola
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Designing a sonic interactive open-ended playground installation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The application of digital elements to traditional playgrounds can enhance children’s outdoor play and counteract the growing trend of sedentary activities. This work reports the implementation and evaluation of a playground installation which looks at sound as the modality that can provide new and engaging play experiences. The design of this system follows an open-ended approach that let the children create their own emerging game goals and rules. The sound design is first tested in a lab setting and later on in a Swedish preschool, with a particular focus on the stages of play (invitation, exploration, and immersion). 38 children between 2 and 6 years old participated in a field study that lasted for three days. Children’s engagement over time was quantified and field notes were taken during the whole evaluation. None of the children between 2 and 3 years old reached the immersion stage. On the other hand, children between 4 and 6 years old created their own rules showing parallel and collaborative play and, in some occasions, solitary play. The sound modality chosen proved to be effective to encourage children’s play in a first place. In a longer engagement perspective, the soundscape partly supported an immersive play. The selection of the sounds to be integrated in the system demonstrated to be as fundamental as the physical appearance of the playground installation. The results of this study show how the visual and auditory modalities can be effective in an open-ended interactive playground and report the limitations of this design.

  • Rintala, Jonathan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Skogetun, Erik
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Designing a Mobile User Interface for Crowdsourced Verification of Datasets2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During the last decade machine learning has spread rapidly in computer science and beyond, and a central issue for machine learning is data quality. This study was carried out in the intersection of business and Human-Computer Interaction, examining how an interface may be developed for crowdsourced verification of datasets.The interface is developed for efficiency and enjoyability through research on areas such as usability, information presentation models and gamification.

    The interface was developed iteratively, drawing from needs of potential users as well as the machine learning industry. More specifically, the process involved a literature study, expert interviews, a user survey on the Kenyan market and user tests. The study was divided into a conceptual phase and a design phase, each constituting a clearly bounded part of the study with a prototype being developed in each stage.

    The results of this study give an interesting insight on what usability factors are important when designing a practical tool-type mobile application, while balancing efficiency and enjoyability. The resulting novel interface indicated on a more effective performance than a conventional grid layout and is more enjoyable to use according to the users. In addition, the ‘rapid serial visual presentation’ can be deemed a well-functioning model for tool-type mobile applications which require a high amount of binary decisions on short time.

    The study highlights the importance of iterative, user-driven processes, allowing a new innovation or idea to merge with the needs and skills of users. The results may be of interest to anyone developing tool-type mobile applications and certainly if binary decision making on images is central.

  • Alemrajabi, Mahmood
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Transport Phenomena.
    Recovery of Rare Earth Elements from an Apatite Concentrate2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rare earth elements (REE) are a group of 17 elements including lanthanides, yttrium and scandium; which are found in a variety of classes of minerals worldwide. The criticality of the application, lack of high grade and economically feasible REE resources and a monopolistic supply situation has raised significant attention in recovery of these metals from low grade ores and waste materials. In this thesis, the recovery of REE from an apatite concentrate, containing 0.5 mass% of REE, within the nitrophosphate route of fertilizer production has been investigated. Most of the REE (≥ 95%) content can be recovered into a phosphate precipitate with almost 30 mass% REE. Different processes have been developed to convert the REE phosphate precipitate into a more soluble form to obtain a solution suitable for further REE purification and individual separation. It has been shown that after reprecipitation of the REE phosphate concentrate as REE sodium double sulphate and then transformation into a REE hydroxide concentrate, a solution containing 45g/L REE free of Ca, Fe and P can be obtained. The results suggest that the apatite waste after processing of iron ore have the potential to be a very important source for REE in Europe and that the economy is strongly supported by the simultaneous extraction of phosphorous.

    The potential of using hollow fiber supported liquid membrane (HFSLM) extraction in individual and group separation of REE has been investigated. A hollow fiber supported liquid membrane plant in pilot scale has been operated according to the three main configurations: standard hollow fiber supported liquid membrane technology (HFSLM); hollow fiber renewal liquid membrane technology (HFRSLM) and emulsion pertraction technology (EPT). The standard HFSLM operation is more selective than HFRSLM and EPT, while higher metal transport rate is observed in EPT followed by HFRSLM and HFSLM. The HFRLM configuration helps to maintain the performance of the liquid membrane.

  • Moliis, Sanna
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Building resilience to climate change in marine social-ecological systems: A study on maritime spatial planning in Finland2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Resilience of marine ecosystems are diminished due to climate change and increased human activities at sea. In the European Union acknowledge the issues in the Integrated Maritime Policy (IMP), and the Maritime Spatial Planning Directive, which obligates member states to develop spatial plans for their coastal- and marine areas. The aim of the maritime spatial plans (MSP) is to promote sustainable blue growth within the marine sector by applying an ecosystem-based approach. One of the objectives of the directive is to encourage member states to enhance resilience to climate change in their plans. This study investigates how maritime spatial plans can enhance resilience against climate change in practice. The issue is approached by evaluating how maritime spatial planning can address general social-ecological resilience principles developed within resilience literature. Data for the evaluation is collected by interviews conducted with regional maritime spatial planners and experts. The study has special focus on the Finnish maritime spatial planning process and is limited to the Gulf of Bothnia where climate change impacts already has been observed, and significant future impacts are expected. The results indicate that there are possibilities to enhance resilience against climate change through MSP. Particularly due to its participatory process which facilitates sharing of experiences, knowledge, innovation and learning between governance scales and stakeholders. The resulting plan itself can potentially enhance resilience of the vulnerable ecosystem by spatially allocating human induced pressures and enhancing habitat connectivity. The strategical character of the maritime spatial plan and the fact that the plan will not be legally binding, facilitates an opportunity for an innovative approach to dealing with climate change in spatial planning. However, the successfulness of the plans depends on the willingness to allocate resources for learning and exploration of the opportunities introduced by MSP.

  • Jiang, Xiaolin
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Wireless Communication Networks for Time-critical Industrial Applications2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wireless communication is of paramount importance to enable the vision of Industry 4.0. Compared to mobile communications, industrial communications pose demanding requirements in terms of ultra low latency and high reliability. Currently, for the most time-critical industrial applications, there is no available wireless solutions satisfying these latency requirements. This thesis studies effective techniques to reduce the latency for the time-critical industrial applications, especially from the Physical Layer (PHY) point of view.

    The thesis is organized in two main parts. In the first part, the available methods for low latency are surveyed and analyzed in terms of end-to-end latency. It is argued that the enabling techniques should be optimized together to reduce the end-to-end latency while satisfying other requirements such as reliability and throughput. Moreover, the realistic timing constraints of different PHY algorithms, hardware, and mechanisms are derived based on the state-of-art wireless implementations. In the second part, a revision of PHY with an optimized PHY structure is proposed to reduce the latency. It is shown that a PHY with just a short one-symbol preamble and dedicated packet detection and synchronization algorithms for short packets is robust to carrier frequency offsets and false alarms by both theoretical and site experiments.

    The investigations of this thesis show that revising the PHY structure/parameters is effective to reduce the packet transmission time, and further improve the latency performance of wireless communication network for time-critical industrial applications. In the future, we include the PHY results of this thesis in the investigation of the Medium Access Control (MAC), for industrial wireless communications with very low latencies.

  • Said, Hana
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Nouri, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Konsten att skapa verklighetsbaserade enhetstider: Specialanpassade för Lindbäcks Bygg AB2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • You, Yantian
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Cloud Auto-Scaling Control Engine Based on Machine Learning2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the development of modern data centers and networks, many service providers have moved most of their computing functions to the cloud.  Considering the limitation of network bandwidth and hardware or virtual resources, how to manage different virtual resources in a cloud environment so as to achieve better resource allocation is a big problem.  Although some cloud infrastructures provide simple default auto-scaling and orchestration mechanisms, such as OpenStack Heat service, they usually only depend on a single parameter, such as CPU utilization and cannot respond to the network changes in a timely manner.<p> This thesis investigates different auto-scaling mechanisms and designs an on-line control engine that cooperates with different OpenStack service APIs based on various network resource data.  Two auto-scaling engines, Heat orchestration based engine and machine learning based online control engine, have been developed and compared for different client requests patterns.  Two machine learning methods, neural network, and linear regression have been considered to generate a control signal based on real-time network data.  This thesis also shows the network’s non-linear behaviors for heavy traffic and proposes a scaling policy based on deep network analysis.<p> The results show that for offline training, the neural network and linear regression provide 81.5% and 84.8% accuracy respectively.  However, for online testing with different client request patterns, the neural network results are different than we expected, while linear regression provided us with much better results.  The model comparison showed that these two auto-scaling mechanisms have similar behavior for a SMOOTH-load Pattern.  However, for the SPIKEY-load Pattern, the linear regression based online control engine responded faster to network changes while heat orchestration service shows some delay.  Compared with the proposed scaling policy with fewer web servers in use and acceptable response latency, both of the two auto-scaling models waste network resources.

  • Xing, Renzhi
    KTH, School of Electrical Engineering and Computer Science (EECS).
    The Compression of IoT operational data time series in vehicle embedded systems2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis examines compression algorithms for time series operational data which are collected from the Controller Area Network (CAN) bus in an automotive Internet of Things (IoT) setting. The purpose of a compression algorithm is to decrease the size of a set of time series data (such as vehicle speed, wheel speed, etc.) so that the data to be transmitted from the vehicle is small size, thus decreasing the cost of transmission while providing potentially better offboard data analysis. The project helped improve the quality of data collected by the data analysts and reduced the cost of data transmission. Since the time series data compression mostly concerns data storage and transmission, the difficulties in this project were where to locate the combination of data compression and transmission, within the limited performance of the onboard embedded systems. These embedded systems have limited resources (concerning hardware and software resources). Hence the efficiency of the compression algorithm becomes very important. Additionally, there is a tradeoff between the compression ratio and real-time performance. Moreover, the error rate introduced by the compression algorithm must be smaller than an expected value. The compression algorithm contains two phases: (1) an online lossy compression algorithm - piecewise approximation to shrink the total number of data samples while maintaining a guaranteed precision and (2) a lossless compression algorithm – Delta-XOR encoding to compress the output of the lossy algorithm. The algorithm was tested with four typical time series data samples from real CAN logs with different functions and properties. The similarities and differences between these logs are discussed. These differences helped to determine the algorithms that should be used. After the experiments which helped to compare different algorithms and check their performances, a simulation is implemented based on the experiment results. The results of this simulation show that the combined compression algorithm can meet the need of certain compression ratio by controlling the error bound. Finally, the possibility of improving the compression algorithm in the future is discussed.