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  • Public defence: 2018-10-19 10:00 Air & Fire Auditorium, Solna
    Redin, David
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Gene Technology.
    Phasing single DNA molecules with barcode linked sequencing2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Elucidation of our genetic constituents has in the past decade predominately taken the form of short-read DNA sequencing. Revolutionary technology developments have enabled vast amounts of biological information to be obtained, but from a medical standpoint it has yet to live up to the promise of associating individual genotypes to phenotypic states of wide-spread clinical relevance. The mechanisms by which complex phenotypes arise have been difficult to ascertain and the value of short-read sequencing platforms have been limited in this regard. It has become evident that resolving the full spectrum of genetic heterogeneity requires accurate long range information of individual haplotypes to be distinguished. Long-range haplotyping information can be obtained experimentally by long-read sequencing platforms or through linkage of short sequencing reads by means of a common barcode. This thesis explores these solutions, primarily through the development of novel technologies to phase short sequences of single molecules using DNA barcoding. A new method for high-throughput phasing of single DNA molecules, achieved by the production and utilization of uniquely barcoded beads in emulsion droplets, is described in Paper I. The results confirm that complex libraries of beads featuring mutually exclusive barcodes can be generated through clonal PCR amplification, and that these beads can be used to phase variations of the 16s rRNA gene which reduces the ambiguity of classifying bacterial species for metagenomics. Paper II describes a second methodology (‘Droplet Barcode Sequencing’) which simplifies the concept of barcoding DNA fragments by omitting the need for beads and instead relying on clonal amplification of single barcoding oligonucleotides. This study also increases the amount of information that can be linked, which is showcased by phasing all exons of the HLA-A gene and successfully resolving all the alleles present in a sample pool of eight individuals. Paper III expands on this work and explores the use of a single molecule sequencing platform to provide full-length sequencing coverage of six genes of the HLA family. The results show that while genes shorter than 10 kb can be resolved with a high degree of accuracy, compensating for a relatively high error rate by means of increased coverage can be challenging for larger genomic loci. Finally, Paper IV introduces the use of barcode-linked reads on an unprecedented scale, with a new assay that enables low-cost haplotyping of whole genomes without the need for predetermined capture sequences. This technology is utilized to generate a haplotype-resolved human genome, call large-scale structural variants and perform reference-free assembly of bacterial and human genomes. At a cost of only $19 USD per sample, this technology makes the benefits of long-range haplotyping available to the vast majority of laboratories which currently rely solely on short-read sequencing platforms.

  • Public defence: 2018-10-19 10:00 Kollegiesalen, Stockholm
    Barkar, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. KTH.
    Modelling phase separation in Fe-Cr alloys: A continuum approach2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The formation of Cr-rich and Fe-rich domains upon ageing of an initially homogeneous Fe-Cr alloy at elevated temperatures (300-600 ºC) is commonly referred to as phase separation. The behaviour originates from a miscibility gap in the Fe-Cr phase diagram. The boundary of the miscibility gap is denoted the binodal, and the line where the second derivative of the molar Gibbs energy w.r.t. composition is zero, the spinodal. In the region between the binodal and spinodal lines, the phase separation is said to occur by means of nucleation and growth. Inside the spinodal line, no thermally activated nucleation event is needed, and the initially homogeneous alloy decomposes "spinodally" into Cr-rich and Fe-rich regions. This type of phase transformation can be viewed as a continuous build up of Cr-rich regions, that also are interconnected, forming a microstructure characteristic for alloys decomposed spinodally. Phase separation has been of great interest within the metallurgical community as well as industry, due to its embritteling effect. Phase separation in Cr-rich ferritic steels, and thus embrittlement, sets a practical upper service temperature of ~300 ºC for Cr-containing ferrites. It is desirable to develop understanding and modelling capability for decomposing alloy systems, since such knowledge could be used to relieve the limitation in service temperature. The current work has been focused around the development and use of computer simulations, using thermodynamic and kinetic input from databases, in order to progress towards alloy design where decomposition is minimized. Simulations in this work are based on solving the so called Cahn-Hilliard equation, where an important parameter is the gradient energy, since it influences both the morphology and rate of decomposition in the simulations. An attempt at formulating a general model for the gradient energy coefficients in multi-component systems has been made, but has yet to be properly tried against experimental data. Improvements, and insights, to the initial state used in simulations has also been achieved. The combination of above mentioned efforts is a step towards a predictive tool for decomposition of complex alloys. Such a tool could not only be an aid in future alloy design, but also be used as an aid as a diagnosis tool in life time assessment of critical components already in use and thereby difficult to assess on site by means of in-destructive testing, typically components in nuclear power facilities.

  • Public defence: 2018-10-19 10:00 F3, Stockholm
    Olfat, Ehsan
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Parameter Estimation of Nonlinearities in Future Wireless Systems2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nowadays, our every-day life is immersed with wireless communications.From our hand-held cell-phones to televisions to navigation systems in cars, all and all are using wireless communications. This usage will even be enormouslyexpanded due to the introduction of the era of 5G-based Internet-of-Things(IoT) which consists wearables, sensors and more smart appliances.Orthogonal frequency division multiplexing is a very well-known commu-nication method which has been utilized in modern standards and technolo-gies due to its high spectral efficiency, simple frequency-domain equalization,and robustness against inter-symbol interference. Nevertheless, the major do-wnside of OFDM systems is the large fluctuations of the amplitudes of theirsignals causing high peak-to-average-power-ratio (PAPR). This forces the po-wer amplifier (PA) in the transmitter’s RF front-end to work in its saturationregion, hence introducing nonlinear distortion to the transmitted signal. Thisis particularly challenging in low-cost and low-power (and even low-weight)devices where a high-quality PA with a large dynamic range is not affordable,using complex digital processing techniques to mitigate the PAPR or to line-arize the PA is not computationally feasible, and introducing input back-offto change the operating point of the PA is not desirable due to decreasingthe power efficiency of the PA, which can be problematic because of the shortbattery-life. On the other hand, there are more resources available for a high-quality base station (or IoT gateway) in terms of power, budget, space and computational complexity, which motivates transferring all the complexity and cost to them and implement receiver-side nonlinearity estimation and compensation algorithms.To compensate the effects of a nonlinear PA on the transmitted signal and lastly detect them correctly, an iterative detection algorithm has been proposed in the literature. However, to use this algorithm successfully, thereceiver first needs to estimate the nonlinearity parameters. The importanceof this is more noticeable in the 5G-based Internet-of-Things networks, inwhich presumedly, numerous low-cost and low-power devices aim to transmitdata to a base station (or an IoT gateway).The focus of this thesis is on estimating the nonlinearity parameters al-ong with channel estimation, nonlinearity distortion mitigation, and symboldetection in future wireless systems deploying OFDM. In particular, we firstconsider an OFDM system with a limiter (clipper) communicating over anAWGN channel, and derive a maximum-likelihood estimator of the clippingamplitude. Next, we consider OFDM systems tranceiving over multi-pathfading channels, and propose a joint channel and clipping amplitude esti-mation algorithm using block-type frequency-domain pilots. Furthermore, we propose a new packet-frame consisting time-domain and frequency-domain pilots to separately estimate channel and clipping amplitude. After, we consider a broader types of memory less nonlinear PA models, and propose a jointestimation-detection algorithm to jointly estimate the nonlinearity parame-ters and channel and detect symbols. Finally, the joint channel and clipping amplitude estimation algorithm is extended to SIMO-OFDM systems. The performance of all of these algorithms are verified by means of simulations

  • Public defence: 2018-10-19 10:00 E3, Stockholm
    Jürgensen, Jan Henning
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering. KTH Royal Institute of Technology.
    Individual Failure Rate Modelling and Exploratory Failure Data Analysis for Power System Components2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A set of vital societal functions such as health and safety are necessary for today's society to function and to secure the life of its individuals. Infrastructure is required to provide and maintain these functions. This for society critical infrastructure includes electronic communication technology, transport systems, oil \& gas supply, water supply, and the supply of electric power. The electric power system plays a central role in the critical infrastructure since it is required to operate all others. Therefore, outages in the power system can have severe consequences not solely for the supply of electricity but also for the supply of water, gas, and food. To provide a reliable and safe power supply, power system operators are applying asset management strategies to investigate, plan, maintain, and utilize the system and its components while improving the performance under its own financial constraints.

    One approach to increase the reliability of the power grid while decreasing costs is maintenance planning, scheduling, and optimization. To optimize maintenance, a reliability measure for power system components is required. The failure rate, which is the probability of failure in a predefined interval, is utilized in maintenance optimization. Thus far, an average failure rate has been assigned to all components of the same type due to a shortage of component failure data. However, this limits the accuracy of maintenance techniques since the component heterogeneity is neglected. Moreover, the actual failure rate is being underrated or overrated and it is a challenge to identify the impact of conducted maintenance tasks.

    This thesis presents how the failure rate accuracy can be improved despite limited failure data available. Firstly, an introduction to failure rate modelling theory, concepts, and definitions is given to provide a common understanding for the later chapters and papers. Secondly, regression models are presented which can be used to model, predict, and characterise the failure rate and failure intensity for power system components. The Cox regression and regression models for count data are applied to two case studies of disconnector and circuit breaker failure data. The results contribute to an improved modelling of the failure rate on individual level but also improve the understanding of risk factor's impact on component failures. However, the aforementioned regression models have rarely been applied in the power system domain due to the limited failure data. Thirdly, the necessity to distinguish between population and individual failure rates is illustrated and risk factors and methods are presented, which are frequently used in failure rate modelling. Moreover, the thesis presents a method to calculate and predict individual failure rates despite the occurrence of actual failures which is of particular advantage for new components.

  • Public defence: 2018-10-19 10:15 D3, Stockholm
    Du, Rong
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Optimal Networking in Wirelessly Powered Sensor Networks2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wireless sensor networks (WSNs) are nowadays widely used for the long-term monitoring of small or large regions, such as lakes, forests, cities, and industrial areas. The performance of a WSN typically consists of two aspects: i) the monitoring performance, e.g., the accuracy and the timeliness of the measurements or estimations produced by the sensor nodes of the WSN; and ii) the lifetime, i.e., how long the WSN can sustain such a performance. Naturally, we would like to have the monitoring performance as good as possible, and the lifetime as long as possible. However, in traditional WSNs, the sensor nodes generally have limited resources, especially in terms of battery capacity. If the nodes make measurements and report them frequently for a good monitoring performance, they drain their batteries and  this leads to a severely shortened network lifetime. Conversely, the sensors can have a longer lifetime by sacrificing the monitoring performance. It shows the inherent trade-off between the monitoring performance and the lifetime in WSNs.

    We can overcome the limitations of the trade-off described above by wireless energy transfer (WET), where we can provide the sensor nodes with additional energy remotely. The WSNs with WET are called wirelessly powered sensor networks (WPSNs). In a WPSN, dedicated energy sources, e.g., static base stations or mobile chargers, transmit energy via radio frequency (RF) waves to the sensor nodes. The nodes can store the energy in their rechargeable batteries and use it later when it is needed. In so doing, they can use more energy to perform the sensing tasks. Thus, WET is a solution to improve the monitoring performance and lifetime at the same time.  As long as the nodes receive more energy than they consume, it is possible that the WSN be immortal, which is impossible in traditional WSNs. 

    Although WPSNs can potentially break the trade-off between monitoring performance and lifetime, they also bring many fundamental design and performance analysis challenges. Due to the safety issues, the power that the dedicated energy sources can use is limited. The propagation of the RF waves suffers high path losses. Therefore, the energy received by the sensor nodes is much less than the energy transmitted from the sources. As a result, to have a good WSN performance, we should optimize the energy transmission on the energy source side and the energy consumption on the nodes side. Compared to the traditional WSN scenarios where we can only optimize the sensing and data communication strategies, in WPSNs, we have an additional degree of freedom, i.e., the optimization of the energy transmission strategies. This aspect brings new technical challenges and problems that have not been studied in the traditional WSNs. Several novel research questions arise, such as when and how to transmit the energy, and which energy source should transmit. Such questions are not trivial especially when we jointly consider the energy consumption part.

    This thesis contributes to answer the questions above. It consists of three contributions as follows.

    In the first contribution, we consider a WPSN with single energy base stations (eBS) and multiple sensor nodes to monitor several separated areas of interest. The eBS has multiple antennas, and it uses energy beamforming to transmit energy to the nodes. Notice that, if we deploy multiple sensor nodes at the same area, these nodes may receive the energy from the eBS at the same time and they can reduce the energy consumption by applying sleep/awake mechanism. Therefore, we jointly study the deployment of the nodes, the energy transmission of the eBS, and the node activation. The problem is an integer optimization, and we decouple the problem into a node deployment problem and a scheduling problem. We provide a greedy-based algorithm to solve the problem, and show its performance in terms of optimality.

    The second contribution of the thesis starts by noticing that wireless channel state information (CSI) is important for energy beamforming. The more energy that an eBS spends in channel acquisition, the more accurate CSI it will have, thus improving the energy beamforming performance. However, if the eBS spends too much energy on channel acquisition, it will have less energy for WET, which might reduce the energy that is received by the sensor nodes. We thus investigate how much energy the eBS should spend in channel acquisition, i.e., we study the power allocation problem in channel acquisition and energy beamforming for WPSNs. We consider the general optimal channel acquisition and show that the problem is non-convex. Based on the idea of bisection search, we provide an algorithm to find the optimal solution for the single eBS cases, and a closed-form solution for the case where the eBS uses orthogonal pilot transmission, least-square channel estimation, and maximum ratio transmission for WET. The simulations show that the algorithm converges fast, and the performance is close to the theoretical upper bound.

    In the third contribution, we consider a joint energy beamforming and data routing problem for WPSNs. More specifically, we investigate the WPSNs consisting of multiple eBSs, multiple sensor nodes, and a sink node. Based on the received energy, the sensor nodes need to decide how to route their data. The problem aims at maximizing the minimum sensing rate of the sensor nodes while guaranteeing that the received energy of each node is no less than that is consumed. Such a problem is non-convex, and we provide a centralized solution algorithm based on a semi-definite programming transformation. We extend this approach with a distributed algorithm using alternating direction method of multipliers (ADMM). We prove that the centralized algorithm achieves the optimal energy beamforming and routing, and we show by simulation that the distributed one converges to the optimal solution. Additionally, for the cases where the energy beamforming options are pre-determined, we study the problem of finding the energy that should be spent on each vector. We observe that, if the pre-determined beamforming options are chosen wisely, their performance is close to the optimal.

    The results of the thesis show that WET can prolong the lifetime of WSNs, and even make them work sufficiently long for general monitoring applications. More importantly, we should optimize the WPSN by considering both the energy provision and the energy consumption part. The studies of the thesis have the potential to be used in many Internet of Things (IoT) systems in smart cities, such as water distribution lines and building monitoring.

  • Public defence: 2018-10-22 11:00 C-6, Stockholm
    Mrazovic, Petar
    KTH, School of Electrical Engineering and Computer Science (EECS), Software and Computer systems, SCS.
    Crowdsensing-driven Route Optimisation Algorithms for Smart Urban Mobility2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Urban mobility is often considered as one of the main facilitators for greener and more sustainable urban development. However, nowadays it requires a significant shift towards cleaner and more efficient urban transport which would support for increased social and economic concentration of resources in cities. A high priority for cities around the world is to support residents’ mobility within the urban environments while at the same time reducing congestions, accidents, and pollution. However, developing a more efficient and greener (or in one word, smarter) urban mobility is one of the most difficult topics to face in large metropolitan areas. In this thesis, we approach this problem from the perspective of rapidly evolving ICT landscape which allow us to build mobility solutions without the need for large investments or sophisticated sensor technologies.

    In particular, we propose to leverage Mobile Crowdsensing (MCS) paradigm in which citizens use their mobile communication and/or sensing devices to collect, locally process and analyse, as well as voluntary distribute geo-referenced information. The mobility data crowdsensed from volunteer residents (e.g., events, traffic intensity, noise and air pollution, etc.) can provide valuable information about the current mobility conditions in the city, which can, with the adequate data processing algorithms, be used to route and manage people flows in urban environments.

    Therefore, in this thesis we combine two very promising Smart Mobility enablers – MCS and journey/route planning, and thus bring together to some extent distinct research challenges. We separate our research objectives into two parts, i.e., research stages: (1) architectural challenges in designing MCS systems and (2) algorithmic challenges in MCS-driven route planning applications. We aim to demonstrate a logical research progression over time, starting from fundamentals of human-in-the-loop sensing systems such as MCS, to route optimisation algorithms tailored for specific MCS applications. While we mainly focus on algorithms and heuristics to solve NP-hard routing problems, we use real-world application examples to showcase the advantages of the proposed algorithms and infrastructures.

  • Public defence: 2018-10-23 09:00 Kollegiesalen, Stockholm
    Lundström, Mats Johan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Kommuners roller och samhällsplaneringens betydelse i energi- och klimatomställningen: En flerfallstudie om utvecklingen i bebyggelse- och transportsektorerna i Alingsås och Västerås 1990-20142018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Antropogenic global climate change challenges require changing approaches and actions in all sectors and all levels of society. International climate targets and commitments need to be complemented with activities and actions at both national and local levels in order to govern urban and societal development in a more climate-sustainable way, which is greatly influenced by our use of energy.

    The aim of the dissertation is to highlight and seek to understand the roles of municipalities and in particular the importance of municipal planning in the global energy and climate change work, focusing on the transport and built environment sectors. The dissertation is principally a qualitative contextual multi-case study that investigates and presents the importance of both actors' and structural relationships and forces – both within and outside the municipal organization – for development in the two case-municipalities of Alingsås and Västerås in the period 1990 to 2014. The content of the dissertation is based on interviews with municipal officials as well as readings of municipal documents and other literature.The multi-case study describes, analyzes and compares how the municipalities of Alingsås and Västerås have handled the development of the energy efficiency and energy supply of buildings and transports. The dissertation uses a broad definition of municipal planning, which includes both spatial, energy, environmental and traffic planning as well as development of municipal visions, at strategic municipal level.

    The municipal planning in Alingsås and Västerås has contributed to increased energy efficiency and reduced climate change impact in the built environment and transport sectors, to a greater extent in Västerås than in Alingsås where development is more agency (actor) driven. Municipal planning has a particularly important communicative function for putting energy and climate issues on the municipal agenda, especially by paying attention to the need to address the issues and reflect on how the challenges can be addressed and turned into policy. The municipalities' strategic spatial planning largely addresses the environmental challenges of transport issues, but does not involve the energy efficiency of the built environment and heat supply. Energy planning primarily concerns municipalities' own building stocks and operations, to a lesser degree non-municipal building stocks and operations. Västerås’ energy plan from the first decade has, however, been important and greatly contributed to increased energy focus and measures both in the municipal and non-municipal building stock.

    The emissions of greenhouse gases in Alingsås and Västerås were considerably lower in 2014 compared with 1990. This is largely due to the shift of heating based on fossil fuels to higher proportions of non-fossil (district) heating but also to the fact that in recent years, the transports are more energy-efficient vehicles and are using fuels with lower proportion of fossil fuels.

    In the built environment sector, the municipalities in their role as property owners have focused on making energy use more effective and switching from electricity and oil based heating to district heating in their own municipal building stock, while trying to be a good example for other property owners. The municipalities have been at the forefront of extensive energy efficiency measures and the construction of highly energy efficient buildings (passive house standard etc). Since the municipalities, as owners of energy companies, had (or eventually created) control over the district heating's energy mix, they could positively influence both the municipal and non-municipal property stock's climate impact. The shift from fossil to more carbon neutral fuel in district heating takes place earlier in Alingsås, since they build a new district heating system from scratch. The phasing out of fossil fuels takes longer time in Västerås that has an older and larger district heating system, but due to an unusually high connection rate, significant emission reductions are followed when the municipal energy company eventually makes new investments in the combined heat and power plant.

    The municipalities have, in their role as public transport commissioners, carried out significant investments and changes in public transport – especially in urban bus transport, which for a long time were quite underdeveloped – contributed to increased public transport. The increase was particularly high in Alingsås.

    Both municipalities have taken on the role of inspirators and models for other actors in energy efficient and climate-friendly built environment and transports. However, the extent to which they affected this is unclear. Both municipalities have sought to influence the non-municipal building stock through specific energy requirements when selling land owned by the municipality, which clearly contributed to a positive result in Västerås, but is more uncertain in Alingsås as development is not monitored.

    It is primarily a change of municipal-external institutional (structural) factors in the form of national government economic control instruments that drive the energy and climate change work in the two municipalities. Especially national energy and carbon taxes, but also other positive and negative economic control instruments in the built environment, energy and transport sectors, create economic incentives among municipalities and other actors to reduce fossil energy use. New knowledge about climate change challenges and changes in public opinion contribute to changes among national government, municipalities and other actors.

    In line with increasing general knowledge about and interest in addressing the increased greenhouse gas emissions, the case-municipalities' ambitions in the energy and climate change work increase over time. Particularly in Västerås, the case study shows the development and building of the municipality's institutional capacity in terms of increased knowledge, common reference frames and views, as well as organizational structure and cross-sectoral collaborative planning processes - contributing to higher municipal energy and climate change ambitions. In Alingsås, the municipality's energy and climate ambitions are increasingly driven by a number of actors in the form of municipal officials in central power positions with access to resources. In Västerås, a political actor (a political party balancing between the two main political left and right-wing alliances) is promoting several initiatives that focus on the municipality’s energy and climate change work. Structural conditions such as municipal size, regional position and local municipal cultures and traditions also affect the orientation and implementation of municipal energy and climate change work.

    The dissertation discusses that both driving actors (policy entrepreneurs) and new ways of organizing and running planning processes are important in the local energy and climate change work. Driving actors, however, can contribute to both positive and negative climate change developments. Well-developed municipal planning processes and other municipal governance tools are particularly important if key municipal actors in central positions do not address energy and climate issues. Furthermore, the change of actors and people due to retirement, incoming new generations with new perspectives and elections affect municipal energy and climate change development.

    The case study shows that Sweden and the two case-municipalities have so far been relatively successful in their energy and climate change work and that municipal planning is an important part in this. But in order to attain with the longer-term global and national climate goals, we face major challenges that require new ways of thinking and acting at different levels of society. Energy efficiency within the existing building stock requires more extensive measures and thus greater incentives for property owners to take it one step further than today. The phasing out of oil and coal in the built environment sector places new demands on development and innovation in the electricity and district heating sectors. The shift from car-focused to a more energy- and climate-efficient urban and transport planning has begun, but will politicians and the general public accept such a societal development? The spatial and development-oriented energy perspective needs to be strengthened in municipal planning, and in addition, energy use and climate change issues need to be addressed from a life-cycle perspective. The issue of how (or to some: if) we should handle climate change challenges is highly a political issue involving values. However, if taken seriously, it is time to prioritize this issue as a central starting point that we always bear in mind when we plan, develop and build our cities and communities of tomorrow.

  • Public defence: 2018-10-23 10:00 Sal F3, Stockholm
    Gu, Zhenhong
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering. KTH - SEED.
    An analysis of architectural and urban planning strategies for developing energy efficient cities in China2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents a detailed analysis of architecture and urban planning strategies for developingenergy-efficient cities in a Chinese context. The overall aim of the work is to examine how Chineseurbanisation and city construction can be improved from an energy-saving perspective.

    China is in the process of transforming from an agricultural to an industrial country, and it willconsume more energy than ever before. Creating energy-efficient cities is an important part ofsustainable energy development. City development is a complicated process that affects the interestsof many stakeholders, and the strategies for establishing energy-efficient cities can be directed at twolevels: components and systems.

    The main components of energy-efficient cities are energy-efficient buildings, which have been a hottopic in recent years. In China, a number of new, stricter codes for energy-efficient buildings arebeing issued. In addition, many research institutes have developed Building EnvironmentalAssessment (BEA) methods, where energy efficiency is an important factor in the models. Varioustechnical solutions for energy efficiency are also being developed. This thesis analyses differentsolutions and their applicability within the Chinese context.

    The investigation in Nanjing clearly demonstrated that system-level strategies are vital for achievingenergy-efficient cities. The Swedish energy efficient models of the housing development HammarbySjöstad and the smaller scale Eco-villages were analysed to see if these solutions were compatiblewith the Chinese context. The strategies to reduce energy demands can be further subdivided intoreducing building energy consumption and reducing transportation energy consumption. Thesestrategies were implemented into the urban design for the southern region of Hexi New City District,Nanjing, which will be used as an example of new urban construction in a rapidly urbanising China.

    This thesis proposes a route for developing energy-efficient cities. In the construction of Chinesecities, technological strategies for energy-efficient buildings have been implemented successfully, butthe systems structure of such cities requires special attention, particularly in the context of rapidurbanisation. Urban planning with energy considerations must be seen as equally important to thedevelopment of energy-efficient buildings. City planners should play a key role in this process, notby saving energy directly, but indirectly, by influencing the behaviour of persons living, working andtravelling within their city. Local and regional governments, which have special powers in China,should take responsibility for policymaking, demonstration, standardisation and education. In thebroad context of intelligent urban planning, technological, economic, and social strategies for energyefficientbuildings will all play a positive role.

    China’s government has started the process of improving urban energy efficiency. However, thisprocess will be difficult and progress will be slow. The thesis discusses the conditions in the Chinesecontext and identifies problems that require solutions in the near future.

  • Public defence: 2018-10-23 14:00 F3, Stockholm
    Malm, Arvid
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Economics.
    The Absent Entrepreneur: Exploring the Role of the Entrepreneur in Economics2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Economics as an academic discipline has often found it difficult to formally model the Entrepreneur. As Baumol (1968) noted, “The theoretical firm is entrepreneurless—the prince of Denmark has been expunged from the discussion of Hamlet.”This dissertation first examines if the entrepreneur is still absent from economics and then seeks to apply the concept of the entrepreneur to some contemporary economic discussions. Finally, I examine a concept closely associated with entrepreneurship: Philanthropy.The first and second article examine the presence of the entrepreneur and the family firm in the current economic “canon” in economics PhD programs. We find that the entrepreneur remains scarce in economics, but that some recent included works attempt to model entrepreneurship. The family firm is entirely absent from the surveyed literature.The third article examines the impact of a major Swedish educational reform that lengthened mandatory education on self-employment outcomes. I find that reform participants are less likely to operate marginal businesses.The fourth article examines income inequality in the United States in relation to entrepreneurship. Using the “Supermanager” hypothesis of Thomas Piketty as a starting point, we argue that entrepreneurs and managers in closely held firms play an important role in rising income inequality.Finally, the fifth article examines the state of Swedish philanthropy, a field usually fueled by successful entrepreneurship. We examine the productivity of philanthropic funding of research relative to other R&D funding and conclude that the main predictor of publication and patent output appears to be overall funding, not funding structure.

  • Public defence: 2018-10-24 13:00 Atrium, Solna
    The, Matthew
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Statistical and machine learning methods to analyze large-scale mass spectrometry data2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Modern biology is faced with vast amounts of data that contain valuable information yet to be extracted. Proteomics, the study of proteins, has repositories with thousands of mass spectrometry experiments. These data gold mines could further our knowledge of proteins as the main actors in cell processes and signaling. Here, we explore methods to extract more information from this data using statistical and machine learning methods.

    First, we present advances for studies that aggregate hundreds of runs. We introduce MaRaCluster, which clusters mass spectra for large-scale datasets using statistical methods to assess similarity of spectra. It identified up to 40% more peptides than the state-of-the-art method, MS-Cluster. Further, we accommodated large-scale data analysis in Percolator, a popular post-processing tool for mass spectrometry data. This reduced the runtime for a draft human proteome study from a full day to 10 minutes.

    Second, we clarify and promote the contentious topic of protein false discovery rates (FDRs). Often, studies report lists of proteins but fail to report protein FDRs. We provide a framework to systematically discuss protein FDRs and take away hesitance. We also added protein FDRs to Percolator, opting for the best-peptide approach which proved superior in a benchmark of scalable protein inference methods.

    Third, we tackle the low sensitivity of protein quantification methods. Current methods lack proper control of error sources and propagation. To remedy this, we developed Triqler, which controls the protein quantification FDR through a Bayesian framework. We also introduce MaRaQuant, which proposes a quantification-first approach that applies clustering prior to identification. This reduced the number of spectra to be searched and allowed us to spot unidentified analytes of interest. Combining these tools outperformed the state-of-the-art method, MaxQuant/Perseus, and found enriched functional terms for datasets that had none before.

  • Public defence: 2018-10-26 10:00 Ka-Sal C (Sal Sven-Olof Öhrvik), Stockholm
    Jayakumar, Ganesh
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics.
    Silicon nanowire based devices for More than Moore Applications2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Silicon nanowires (SiNW) are in the spotlight for a few years in the research community as a good candidate for biosensing applications. This is attributed to their small dimensions in nanometer scale that offers high sensitivity, label-free detection and at the same time utilizing small amount of sample. While the recent research has concentrated predominantly on utilizing single or multiple SiNW for biosensing applications, very few attempts have been made to integrate SiNW with complementary-metal-oxide- semiconductor (CMOS) integration to arrive at a complete lab-on-chip (LOC) sensor. Further, the manufacturing methods reported thus far in the production of SiNW for biosensing applications have not fully exploited both the front-end-of-line (FEOL) as well as back-end-of-line (BEOL) methods in CMOS integration. Neither does the research community address CMOS integration based methods to realize multi and specific target detection that are important attributes for an ideal LOC biosensor.

    Integration of SiNW with CMOS circuitry will facilitate real time detection of the output signal and in addition provide a compact small sized sensor that is fully portable operating at high speed. In order to avail the benefits of CMOS circuits and develop a large scale production friendly LOC sensor, the scheme of SiNW fabrication has to facilitate either the FEOL or BEOL CMOS integration schemes. This thesis work is focused on revealing a novel FEOL as well as BEOL scheme for integration of SiNW with CMOS circuitry. The major part of the FEOL research work is concentrated on developing a high volume SiNW manufacturing method that is suitable for industrial production. Likewise, in the BEOL scheme, predominant focus was to develop a wafer scale scheme to integrate network of nanowires (nanonets) with CMOS circuitry to manufacture a monolithic 3D above-IC LOC biosensor.

    In the FEOL scheme, the SiNWs are fabricated using a revised pattern transfer technique called sidewall transfer lithography (STL). The STL method is identified as one of the efficient methods of fabricating SiNW as it uses CMOS industry grade materials that is fully compatible with the FEOL fabrication scheme. Thanks to the usage of single lithography and controlled selective etching techniques used in the STL process, the line width and aspect ratio of the SiNW can be tailored to suit the requirements for DNA hybridization detection. A fabrication process flow matching standard CMOS process integration flows has been developed to integrate SiNW with HfO2 and TiN metal gate MOSFETS. An emphasis has been placed in the design of a novel pixel matrix based SiNW LOC sensor. Specific and multi-target detection has been kept as top priority in the design of the SiNW LOC sensor. The possibility to monitor the potential of the electrolyte during the detection process using a fluid gate has been accounted in this design. Furthermore, the SiNW pixel design eliminates the intricate microfluidics and eases access to the SiNW test site using a simple photolithography mask and RIE. The SiNW and MOSFETS demonstrate excellent electrical characteristics. For the very first time, the concept to access single as well as multiple array SiNW pixels using a transistor has been successfully demonstrated.

    In the BEOL scheme, the nanonets are fabricated using the bottom-up method and transferred onto a pre-fabricated CMOS wafer supplied by ams foundry. The connection between the nanonets lying above-IC and the underlying CMOS layer was established by employing a thin metal backgate electrode, backgate dielectric and metal source/drain contact pads. Many challenges in the BEOL scheme have been identified and overcome by incorporating efficient device architecture and careful selection of materials. To the first of its kind, a wafer scale process was developed to integrate nanonets with CMOS to form a monolithic 3D IC. The devices exhibit excellent electrical characteristics and lower leakage currents compared to standalone nanonet sensors fabricated on Si/SiN substrate. Further, the FEOL and BEOL integration schemes are compared and the various pro’s and con’s of both approaches for integration of SiNW with CMOS circuits to build a LOC biosensor are discussed in detail.

    Finally, dry environment DNA hybridization detection is demonstrated on the surface of thin HfO2 encapsulated SiNW sensors. Upon DNA hybridization, SiNW devices exhibit threshold voltage shift larger than the noise introduced by the exposition to saline solutions used for the bio-processes. More specifically, based on a statistical analysis, it is demonstrated that 85% of the tested devices were efficient for DNA hybridization detection. The estimated density of hybridized DNA was in the order of 1010 cm-2. These promising results of realizing a SiNW based lab-on-chip platform through the FEOL and BEOL monolithic integration of SiNW and CMOS circuitry further strengthen the profile of SiNW as a nano biosensor. Indeed, this is expected to pave the way for more than Moore applications of SiNW based devices and integrated circuits.

  • Public defence: 2018-10-26 10:00 Gardaulan, Solna
    Asp, Michaela
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Gene Technology.
    Spatially Resolved Gene Expression Analysis2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Spatially resolved transcriptomics has greatly expanded our knowledge of complex multicellular biological systems. To date, several technologies have been developed that combine gene expression data with information about its spatial tissue context. There is as yet no single spatial method superior to all others, and the existing methods have jointly contributed to progress in this field of technology. Some challenges presented by existing protocols include having a limited number of targets, being labor extensive, being tissue-type dependent and having low throughput or limited resolution. Within the scope of this thesis, many aspects of these challenges have been taken into consideration, resulting in a detailed evaluation of a recently developed spatial transcriptome-wide method. This method, termed Spatial Transcriptomics (ST), enables the spatial location of gene activity to be preserved and visually links it to its histological position and anatomical context. Paper I describes all the details of the experimental protocol, which starts when intact tissue sections are placed on barcoded microarrays and finishes with high throughput sequencing. Here, spatially resolved transcriptome-wide data are obtained from both mouse olfactory bulb and breast cancer samples, demonstrating the broad tissue applicability and robustness of the approach. In Paper II, the ST technology is applied to samples of human adult heart, a tissue type that contains large proportions of fibrous tissue and thus makes RNA extraction substantially more challenging. New protocol strategies are optimized in order to generate spatially resolved transcriptome data from heart failure patients. This demonstrates the advantage of using the technology for the identification of lowly expressed biomarkers that have previously been seen to correlate with disease progression in patients suffering heart failure. Paper III shows that, although the ST technology has limited resolution compared to other techniques, it can be combined with single-cell RNA-sequencing and hence allow the spatial positions of individual cells to be recovered. The combined approach is applied to developing human heart tissue and reveals cellular heterogeneity of distinct compartments within the complete organ. Since the ST technology is based on the sequencing of mRNA tags, Paper IV describes a new version of the method, in which spatially resolved analysis of full-length transcripts is being developed. Exploring the spatial distribution of full-length transcripts in tissues enables further insights into alternative splicing and fusion transcripts and possible discoveries of new genes.  

  • Public defence: 2018-10-26 10:00 FA32, Stockholm
    Baghban, Mohammad Amin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Integrated Nanophotonic Devices in Lithium Niobate2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lithium niobate (LN) is a ferroelectric crystal offering a broad transparency spectrum, together with excellent electro-optic and nonlinear optical properties. Thanks to them, LN is setting the standard for quantum optics and telecommunications in critical applications such as ultrafast modulation and frequency conversion. The development of a reliable nanophotonic platform in LN can be expected to effectively leverage all such appealing functionalities in compact and integrated formats and provide important and complementary functionalities to current silicon-photonics platforms.

    This thesis encompasses systematic and consistent efforts with the goal to achieve the key building blocks for a comprehensive integrated nanophotonic platform in LN. It involves work on the technology side, sustained and complemented by modelling and experiments, ultimately leading to the demonstration of a few novel devices.

    Ultrahigh field confinement in nanophotonic waveguides is accompanied by the appearance of non-negligible longitudinal components in the guided optical fields. By fabricating high-quality LN nanopillars and analyzing with theory and experiments their second harmonic generation (SHG) response, we provide evidence for the existence of longitudinal field components and demonstrate the possibility to reshape the SHG polar emission properties of these submicrometric waveguides by fine-tuning the nanopillar size.

    This thesis also presents a different technological approach, allowing the fabrication of photonic wires as small as 250 nm with lengths up to 1 cm on LN-on-insulator (LNOI), suitable for upscaling to photonic integrated circuit (PIC) architectures. By optimizing the fabrication process, the propagation losses of single-mode waveguides at telecom wavelengths on this platform were brought down from 76 to 1.13 dB/cm. Fine-pitch waveguide structuring was also successfully achieved, enabling LNOI-to-fiber grating couplers and waveguide Bragg gratings, the latter featuring record extinction ratios in LNOI (45 dB), comparable to the state of the art in silicon.

    The thesis involves also theoretical work on the design of photonic wires where the interplay between LN and waveguide birefringence is used to achieve polarization-insensitive operation for the fundamental guided modes.

    Finally, two demonstrators are provided for novel and emerging applications of LN to the life sciences, using LNOI surface-patterned templates for enhanced Raman spectroscopy and LN templates for controlled neuron growth and manipulation in microfluidic environments, respectively.

  • Public defence: 2018-10-26 13:00 K1, Stockholm
    Kürten, Charlotte
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    On Catalytic Mechanisms for Rational Enzyme Design Strategies2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Enzymes enable life by promoting chemical reactions that govern the metabolism of all living organisms. As green catalysts, they have been extensively used in industry. However, to reach their full potential, engineering is often required, which can benefit from a detailed understanding of the underlying reaction mechanism.

    In Paper I, we screened for an esterase with promiscuous amidase activity capitalizing on a key hydrogen bond acceptor that is able to stabilize the rate limiting nitrogen inversion. In silicoanalyses revealed the esterase patatin as promising target that indeed catalyzed amide hydrolysis when tested in vitro. While key transition state stabilizers for amide hydrolysis are known, we were interested in increasing our fundamental understanding of terpene cyclase catalysis (Paper II-V). In Paper II, kinetic studies in D2O-enriched buffers using a soluble diterpene cyclase suggested that hydrogen tunneling is part of the rate-limiting protonation step. In Paper III, we performed intense computational analyses on a bacterial triterpene cyclase to show the influence of water flow on catalysis. Water movement in the active site and in specific water channels, influencing transition state formation, was detected using streamline analysis. In Paper IV and V, we focused on the human membrane-bound triterpene cyclase oxidosqualene cyclase. We first established a bacterial expression and purification protocol in Paper IV, before performing detailed in vitroand in silicoanalyses in Paper V. Our analyses showed an entropy-driven reaction mechanism and the existence of a tunnel network in the structure of the human enzyme. The influence of water network rearrangements on the thermodynamics of the transition state formation were confirmed. Introducing mutations in the tunnel lining residues severely affected the temperature dependence of the reaction by changing the water flow and network rearrangements in the tunnels and concomitant the active site.

  • Public defence: 2018-10-26 13:00 FB42, Stockholm
    Borgani, Riccardo
    KTH, School of Engineering Sciences (SCI), Applied Physics, Nanostructure Physics.
    Probing nonlinear electrical properties at the nanoscale: Studies in multifrequency AFM2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nanostructured materials promise great advances in diverse and active research fields such as energy harvesting and storage, corrosion prevention and high-density memories. Electrical characterization at the nanometer scale is key to understanding and optimizing the performance of these materials, and therefore central to the progress of nanotechnology. One of the most versatile tools for this purpose is the atomic force microscope (AFM), thanks to its ability to image surfaces with high spatial resolution.

    In this thesis we present several multifrequency techniques for AFM. Intermodulation electrostatic force microscopy (ImEFM) measures the potential of a surface with low noise and high spatial resolution. In contrast to traditionally available methods, ImEFM does not use a feedback-controlled bias to measure the surface potential, and is therefore suitable to measurements in liquid environments. Removing feedback allows the applied bias to be used for investigating charge injection and extraction on nanocomposite materials. Intermodulation conductive AFM (ImCFM) measures the current-voltage characteristic of a sample at every point of an AFM image. ImCFM is able to separate the galvanic and displacement contributions to the measured current, improving the measurement speed by four orders of magnitude compared to previously available methods. We finally demonstrate an alternative approach to pump-probe spectroscopy, which allows the AFM to measure electrical charge dynamics with a time resolution approaching the nanosecond range.

    These techniques are based on intermodulation spectroscopy, and they demonstrate the power and flexibility of measuring and analyzing nonlinear response in the frequency domain. The nonlinearity of the tip-surface force is used to concentrate response in a narrow band around the resonance of the AFM cantilever, where force measurement sensitivity is at the thermal limit. In this narrow band, we perform coherent measurements at multiple frequencies by exploiting the stability of a single reference oscillation. The power of the multifrequency approach is nicely demonstrated in a general method for measuring and compensating background forces, i.e. long-range linear forces that act on the body of the AFM probe. This compensation is necessary to reveal the the true force between the surface and the AFM tip. We show the effect of the compensation on soft polymer materials, where the background forces are typically strongest.

  • Public defence: 2018-10-26 14:00 F3, Stockholm
    Ni, Shengjun
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Carbocation Catalysis for Organic Synthesis2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The most common view of carbocations in organic chemistry is that they are short-lived intermediates in several fundamental reactions, e.g. the classic SN1-reaction. However, carbocations that can delocalize their positive charge can be stable enough to be isolated and used as Lewis acid catalysts, phase transfer catalysts or oxidants in various reactions. The theme of this thesis concerns applying trityl cations as Lewis acid catalysts in different organic reactions. The first chapter presents a general introduction of the field of Lewis acids, the characteristics and applications of carbocations in different organic reactions, and the aims of this thesis. The second chapter describes the carbocation-catalyzed asymmetric Diels–Alder reactions assisted by chiral counteranions. The third chapter shows that carbocations can be utilized as catalysts in oxa-Diels–Alder reactions with unactivated aldehydes and dienes as substrates. The fourth chapter investigates the application of carbocation catalysis in bromination reactions for selective functionalization at the benzylic position and on the aromatic ring, respectively. The fifth chapter highlights that carbocation-catalyzed aldehyde–olefin metathesis reactions can be achieved in high yields by suppressing the decomposition of both starting materials and products.

  • Public defence: 2018-10-26 14:00 Kollegiesalen, Stockholm
    Pabon, Peter
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH. Institute of Sonology, Royal Conservatory.
    Mapping Individual Voice Quality over the Voice Range: The Measurement Paradigm of the Voice Range Profile2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The acoustic signal of voiced sounds has two primary attributes: fundamental frequency and sound level. It has also very many secondary attributes, or ‘voice qualities’, that can be derived from the acoustic signal, in particular from its periodicity and its spectrum. Acoustic voice analysis as a discipline is largely concerned with identifying and quantifying those qualities or parameters that are relevant for assessing the health or training status of a voice or that characterize the individual quality. The thesis presented here is that all such voice qualities covary essentially and individually with the fundamental frequency and the sound level, and that methods for assessing the voice must account for this covariation and individuality. The central interest in the "voice field" measurement paradigm becomes to map the proportional dependencies that exist between voice parameters. The five studies contribute to ways of doing this in practice, while the framework text presents the theoretical basis for the analysis model in relation to the practical principles.

  • Public defence: 2018-10-30 13:00 F3, Stockholm
    Ignat, Razvan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Ground Improvement by Dry Deep Mixing Lime-Cement Column Panels as Excavation Support2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Many urban areas near the coastal regions of Sweden are characterized by post-glacial clay deposits with very low undrained shear strength and high compressibility. Column type ground improvement by the Deep Mixing, DM, method using a binder mixture of lime and cement is commonly used in areas with poor soil conditions due to its cost-effectiveness, predominantly for settlement reduction and to improve the stability of embankments. With increasing urbanization and infrastructural development in these areas there is great interest in the industry in extending the practice of the Deep Mixing method to include other applications such as deep excavation and temporary and permanent improvement of natural slopes. Swedish experience related to use of the DM method for excavation support is limited and the current design recommendations for DM columns installed in the passive zone are very restrictive regarding the allowable mobilized column strength, resulting in a design which is often not cost-effective.

    In order to increase the use of the method to include applications where DM columns are subjected to unloading and lateral loading conditions, the mobilized strength and stiffness properties of the columns as well as the soil-column interaction need to be reliably predicted. The main objective of this study is to present a consistent method to adequately predict the behavior of lime-cement columns installed as excavation support in the passive zone of the structure and to investigate the strength and stiffness properties of lime-cement improved clay under different unloading and laterally loading conditions together with the soil-column interaction under these conditions.

    In order to investigate the field behavior of lime-cement column panels as excavation support, two experimental full-scale tests were performed. In each of these tests, a braced steel sheet pile wall supported by panels of overlapping lime-cement columns was first excavated to a pre-determined depth and thereafter loaded to failure by stepwise increasing a load applied behind the sheet pile wall. The tests provided a case record of deformations, stresses, and pore pressure responses, and failure mechanisms of the structures focusing on the improved soil. These tests showed that column-type ground improvement installed as panels of overlapping columns in the passive zone of a sheet pile wall significantly increases stability and reduces both excavation- and loading-induced structural forces and vertical and horizontal displacements in the soil.

    This thesis also presents the results of a laboratory study involving undrained and drained isotropic consolidated triaxial compression, extension and tension tests on laboratory improved clay with a binder of lime-cement similar to that used in the experimental field tests. Based on undrained triaxial test results, a relationship between the undrained strength, effective consolidation stress, and overconsolidation ratio is presented for different stress paths to failure. From the drained triaxial tests it was found that a failure surface comprising of two failure functions, one for tension failure and one for shear failure, similar to that observed for cemented sand, is consistent with the experimental data. Finally, a 3D FE-study of the experimental field tests considering the laboratory observed stress-strain behavior and mobilized strength of lime-cement improved clay was conducted. The results of these analyses are promising and failure load, deformations and structural forces in the retaining structure were predicted reasonably well.

    Summarizing the most important findings and conclusions from this study:

    -          Lime-cement columns panels installed in the passive zone acting as excavation support for a sheet pile wall will significantly increase the stability of the structure.

    -          Lime-cement column panels installed as excavation support are effective in reducing excavation induced displacements that can be of major concern for deep excavations conducted in areas with soft clay layers.

    -          The undrained strength of lime-cement improved clay at low consolidation stresses, corresponding to approximately 10 m of depth in field conditions, is dependent of the stress path to failure and it was found to be significantly lower for unloading stress paths compared to lateral loading stress paths, i.e. stress induced anisotropy. 

    -          The Young’s Modulus of lime-cement improved clay evaluated from undrained triaxial extension tests was significantly higher, 2.7 to 4.1 times, compared to the corresponding Young’s Modulus evaluated from the undrained triaxial compression tests. Also, significantly more brittle stress-strain behaviour was observed for triaxial extension tests compared to triaxial compression tests, regardless of applied stress path to failure and type of test, i.e. undrained/drained. 

    -          Results of the Finite Element analysis of the conducted experimental tests show that the current Swedish Design Guide for lime-cement columns installed in the passive zone overestimates the material undrained strength when based on results from Unconfined Compression tests, but also significantly underestimates the material drained strength. Since the Swedish Design Guide specifies that the lowest of the undrained/drained column strength should be chosen in the design, the consequence is often a too conservative design as the strength increase in the improved clay is not properly considered.

  • Public defence: 2018-10-31 09:00 T2, Huddinge
    Yang, Kunlong
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH). KTH, School of Electrical Engineering and Computer Science (EECS).
    Flexible Electrical and Photoelectrical Artificial Synapses for Neuromorphic Systems2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Over the past decade, the field of personal electronic systems has trended toward mobile and wearable devices. However, the capabilities of existing electronic systems are overwhelmed by the computing demands at the wearable sensing stage. Two main bottlenecks are encountered. The first bottleneck is located within the computing module, between the processing units and the memory, and is known as the von-Neumann bottleneck. The second bottleneck is located between the sensing module and the computing module of the system.

    Inspired by neuromorphic computing, an architecture of the sensitive neuromorphic network (SNN) is developed as a candidate for overcoming both bottlenecks. Suitable building blocks, especially in flexible form, must be developed. In this work, starting from the demand analysis and followed by prototype development, performance optimization, and feasibility testing, two kinds of critical devices were developed for fabricating a photosensitive neuromorphic network (PSNN).

    A high-performance flexible electrical artificial synapse that is based on the electron-trapping mechanism was developed. In addition to the basic memristive features, multiple kinds of synaptic plasticity were also demonstrated, which enriched the collection of possible applications. Furthermore, optimization on multiple performance metrics was easily performed using the intrinsic features and structure of the device.

    A new photoelectrical artificial synapse was also realized by successfully combining light signal sensing and processing in a single synapse. A flexible dual-mode photoelectrical synapse, which fulfilled the requirements of the designed PSNN working protocol, was demonstrated. The device showed gate-tunable photomemristive features, thereby enabling its application as a photoelectrical artificial synapse.

    Using the newly developed devices and the proposed network architecture, this work successfully initiated a new area of research, namely, the sensitive neuromorphic network, and provided a valid solution that addresses the current limitations of existing wearable electronic systems.

  • Public defence: 2018-10-31 10:15 Oskar Kleins Auditorium, Stockholm
    Thatikonda, Naresh
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Functionalization of spider silk with affinity and bioactive domains via genetic engineering for in vitro disease diagnosis and tissue engineering2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the recent past, spider silk has drawn significant attention from researchers mainly due to its distinguished mechanical strength, elasticity, biocompatibility and biodegradability. Technological advancements in genetic engineering have resulted in methods for creation of partial spider silk proteins. The main objective of this thesis has been to functionalize a partial spider silk protein, 4RepCT, with different affinity and bioactive domains via genetic engineering. Furthermore, the applicability of materials based on functionalized/bioactivated partial spider silk proteins for in vitro disease diagnosis and tissue engineering applications has been investigated.

    In Paper I, four affinity domains of different sizes and folds were genetically attached to 4RepCT. All four silk fusion proteins could self-assemble to silk-like fibers. The retained ability of each added affinity domain to bind its respective target while in silk format was also verified. A construct where a monomeric streptavidin domain was genetically fused to 4RepCT was used to allow non-covalent presentation of biotinylated growth factors. Such materials have potential for applications where capture of growth factors could be advantageous, for example in vitro cell culture studies.

    In Paper II, as a proof-of-concept, two recombinant antibody fragments (scFvs), previously shown to contribute to the candidate protein signature for diagnosing Systemic Lupus Erythematosus (SLE), were covalently attached to either ends of two types of partial spider silk proteins, 4RepCT and NTCT. All of the generated silk fusion proteins were shown able to self-assemble into fibres as well as defined spots in an array. Significantly higher target detection signal was reported from scFv-silk fusion proteins when compared to the same added amount of scFvs alone in micro- and nanoarrays. Thus, scFv-silk fusion proteins can be used as capture probes in the generation of sensitive diagnostic immunoassays for effective disease diagnosis.

    In Paper III, bioactivation of 4RepCT with a pleiotropic growth factor, basic fibroblast growth factor (bFGF) was investigated. The generated silk-bFGF fusion protein retained the propensity to self-assemble into surface coatings and silk-like fibers. Maintained functionality of the silk-bFGF coating to bind FGFR receptor was confirmed using surface plasmon resonance studies. Moreover, with the aim to create an artificial ECM, silk-bFGF protein was combined with FN-silk, an engineered spider silk protein previously reported to support cell adhesion. Retained bioactivity of the bFGF was confirmed by culture of primary human endothelial cells on combined silk coatings and within combined silk fibers, even when cultured in medium containing low serum and no supplemented soluble growth factors. These findings highlight the use of combined silk coatings for in vitro cell culture, and combined silk fibers as a potential scaffold for tissue engineering applications.

    In Paper IV, the possibility to genetically fuse two affibody-based VEGFR2 binders, Zdimer and Ztetramer, to 4RepCT was investigated. Maintained activity of added engineered affibodies was confirmed by receptor phosphorylation and cell proliferation studies. Furthermore, the possibility to create vessel-like structures within a FN-silk based cell scaffold containing Ztetramer-silk fibrils was reported. These findings highlight the future potential of herein developed silk based cell scaffolds in regenerative medicine.

  • Public defence: 2018-11-01 10:00 Kollegiesalen, Stockholm
    Zhang, Chi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Energy Processes.
    Sustainable Business Innovation of Photovoltaic Water Pumping Systems2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The development of renewable energy technology provides an effective approach to replace fossil fuels for greenhouse gas (GHG) emission. Technological innovation and transfer are the main driving forces in promoting renewable energy usage, because of the better efficiency and economic payback under an emission reduction target. With three of the mechanisms of emission trading originating from the Kyoto Protocol, the most wildly accepted and important mechanism between developed and developing countries is the Clean Development Mechanism (CDM). The CDM has been implemented contributing the most of the trading carbon credits. In this study, by extracting and building an exclusive database of issued Chinese CDM projects, a modified multivariable logistic regression model for technology transfer’s correlation test with 11 extended indicators was investigated for the first time. Renewable energy projects were analyzed with certified emission reduction (CER) sizes, economic development, and geographic scopes.In addition, technological innovation should also be enhanced with new business developments to demonstrate and scale up technologies for better economic and environmental performances. This doctoral thesis studied photovoltaic water pumping (PVWP) technology as a technological solution for integration with the new business model for development and co-benefits. The integration of PVWP with water saving irrigation techniques and sustainable management of water resources, leads to technical innovations, economic benefits, and climate benefits. Field measurements at a pilot PVWP system in Inner Mongolia were conducted with detailed economic performance analyses. Different scenarios for PVWP systems considering variant market incentives were proposed with internal rate of return (IRR), and discounted payback period analyses to develop a new business model approach for implementing PVWP systems with multi-value propositions. The environmental externalities were successfully addressed by evaluating the CO2 emission reduction credits. The economic assessment of feasible and optimal production processes for implementing PVWP systems in dairy milk production was conducted with self-supplied energy and forage assumptions. In comparison with other financing mechanisms, discrete choice model analyses were employed with interviews and costumer behavior surveys to explore the willingness to purchase through crowd funding mechanisms in financing integrated PVWP systems.The results showed that emission reduction mechanisms, such as CDM, have promoted the renewable energy development in China with the national incentives at an entrance level. Yet, the limited sizes and lower income from CERs of renewable energy projects than other projects, required renewable energy projects to develop more advanced technological innovations and business model innovations.  The PVWP systems represent the better technical and economic solutions under a feasible innovated business model in comparison with traditional photovoltaic (PV) systems and current PV business models. The dairy farms with integrated PVWP systems and self-sufficient feeds could improve their investment performance through extra energy saving and CO2 emission reductions. The semi-structured interviews and customer surveys’ results showed that customers can tolerate high prices, and are willing to crowd-fund nutritious and secure cow milk with environmental compensation characters. The results from the PVWP technology integration in China as a specific PV application study can be further applied for the business model of innovation of renewable energy systems in other regions of the world under emission reduction targets leading to economic and environmental benefits.

    The full text will be freely available from 2019-10-01 19:10
  • Public defence: 2018-11-02 13:00 F3, Stockholm
    Grünloh, Christiane
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Harmful or Empowering?: Stakeholders’ Expectations and Experiences of Patient Accessible Electronic Health Records2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Healthcare systems worldwide face organisational and financial challenges due to increasing number of people with chronic conditions, increasing costs, and an ageing population. eHealth services have the potential to address some of these challenges, for example, by supporting patients who are engaged in self-care, improving quality of care, and reducing medical costs.

    In 2012, Region Uppsala in Sweden launched an eHealth service that enabled patients to access their electronic health records through the Internet. The launch of the service was accompanied by strong criticism from healthcare professionals (HCPs) and was heavily debated in the media. Patients on the other hand were very positive towards the service.

    Albeit promising, the potential of Patient Accessible Electronic Health Records (PAEHRs) cannot be realised if HCPs still have reservations towards the service and their concerns are not fully understood. The purpose of this research is therefore to enhance our understanding of how physicians view PAEHR in relation to both their work environment and the level of patient participation. Furthermore, the aim is to shed light on whether their concerns related to patients’ well-being have materialised in practice and how patients view and make use of the service. Finally, this thesis identifies implicated human values and value tensions related to PAEHR.

    To enhance our understanding of the physicians’ perspective, semi-structured interviews with 12 physicians in Uppsala were thematically analysed. A national patient survey was conducted to investigate patients’ use of and their experiences with PAEHR. Furthermore, empirical and conceptual investigations were carried out to identify human values and value tensions.

    The results of this research show that the physicians’ assumptions and views of PAEHR and its consequences for patients were different from the views and actual experiences of patients using the PAEHR system. The physicians were mainly concerned about potential increase in their workload and that it could be harmful for patients to access their Electronic Health Record (EHR), for example, as it might evoke anxiety or worry. The vast majority of patients appreciated timely access to their results, felt more involved in their care, and read their records to become more involved. The investigation of human values associated with PAEHR identified values such as Ownership & Property, Professional Autonomy, Responsibility, Human Well-Being, Accountability & Transparency, and Trust. Furthermore, value tensions were identified that may occur between direct and indirect stakeholders (here: patients and physicians), or are related to an interpretation of PAEHR.

    This thesis contributes to current research on eHealth in Human-Computer Interaction (HCI) by instigating a critical discussion of values associated with eHealth technologies that might be perceived as conflicting given a stakeholder’s framing of the technology. For example, tensions that emerge between values that prioritise placing the responsibility on a physician for their patients versus a value system that prioritises patient autonomy. The findings of this thesis suggest that while policymakers and government agencies adhere to a system of values that place a premium on patient empowerment, paternalistic tendencies are still present among physicians. However, an eHealth service like PAEHR is an important first step towards patient participation. The results of this thesis suggest that the support of patient participation in their own care through PAEHR outweighs the potential harm.

  • Public defence: 2018-11-15 10:00 Gard aulan, Solna
    Sjöstedt, Evelina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Systems Biology.
    Towards a deeper understanding of the human brain2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Identifying the proteome variation in different parts of the body provides fundamental molecular details, enabling further findings and mapping of tissue specific proteins. By combining quantitative transcriptomics with qualitative antibody based proteomics, the Human Protein Atlas (HPA) project aims to protein profile each human protein-coding gene. Genes with varying expression levels in the different tissue types are categorized as tissue elevated in one tissue compared to others, thus connecting genes to potential tissue specific functions. This thesis focuses on the most complex organ in the human body, the brain. With its billions of neurons specifically organized and interconnected, the ability of not only controlling the body but also responsible for higher cognitive functions, the brain is still not fully understood.

    In my search for brain important proteins, genes were classified at different stages based on expression levels. In Paper I and II the transcriptome of cerebral cortex was compared with peripheral organs to classify genes with elevated expression in the brain. Brain expression information was expanded by including external data (GTEx and FANTOM5) into the analysis, in Paper III. Thereafter, in Paper IV, the three datasets (HPA, GTEx and FANTOM5) were aligned and combined, enabling a consensus classification with an improved representation of the brain complexity. The most recent classification provided whole body gene expression profiles and out of the 19,670 protein-coding genes, 2,501 were expressed at elevated levels in the brain compared to the other tissue types. Twelve individual regions represented the brain as an organ, and were further analyzed and compared for regional classification of gene expression. One thousand genes showed regional variation in expression level, thus classified as regionally elevated within the brain. Interestingly, less than 500 of the genes classified as brain elevated on the whole body level, and were also regionally elevated in the brain. Many genes with regionally variable expression within the brain showed higher expression in a peripheral organ than in the brain when comparing whole body expression. Based on elevated expression in the brain or brain regions, more than 3,000 genes were suggested to be of high importance to the brain.

    In addition, this high-throughput approach to combine transcriptomics and protein profiles in tissues and cells further generated new knowledge in several different other aspects: better understanding of uncharacterized and “missing proteins” (Paper III), validation of an antibody improving classification of pituitary adenoma (Paper V) and in Paper VI the possibility to explore cancer specific expression in relation to clinical data and normal tissue expression.

    There are multiple diseases of the brain that are poorly understood on both a cellular and molecular level. While my work mainly focused on identifying and understanding the molecular organization of the normal brain, the ultimate goal of mapping and studying the normal expression baseline is to understand the molecular aspects of disease and identify ways to prevent, treat and cure diseases.

  • Public defence: 2018-11-21 09:00 Hörsal F3, Stockholm
    Pajevic, Ljubica
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Performance Analysis of Opportunistic Content Distribution via Data-driven Mobility Modeling2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An opportunistic network is formed by co-located mobile users in order to exchange data via direct wireless links when their devices are within transmission range, without relying on the use of fixed network infrastructure. In this thesis we investigate the capabilities of opportunistic networks and cover two main areas: data-driven modeling of user mobility and analytic performance evaluation of location-aware opportunistic content distribution.The first part of the thesis focuses on mobility modeling. We collect a dataset of user associations in the wireless network of the KTH Royal Institute of Technology, and characterize the mobility of users in this dataset both from the network and from the user perspective. From the network perspective, we model the aggregate mobility and access patterns to different parts of the network. To characterize individual mobility, we assess how mobile the users are, and how accurately their movements can be predicted in the near future. Based on these findings, and on the analysis of several other mobility traces, we propose a mobility model for populations with churn, that is specifically tailored for the evaluation of opportunistic content distribution. In the second part of the thesis, we evaluate the performance of opportunistic content distribution in ephemeral, location-aware networks where content is stored only on the user devices within the locale of interest. We develop a framework that allows modeling of the spread of information as a stochastic process and accurate capturing of the stochastic fluctuations in the number of distributed content items. We study the feasibility of opportunistic content distribution and, by means of stochastic stability analysis, assess how the system parameters can be engineered to ensure content persistence. We show that the content persistence strongly depends on the density of users, and that the requirements for user resources are relatively low already for moderate densities.

    The full text will be freely available from 2018-10-29 08:00
  • Public defence: 2018-11-30 12:30 Senaatzaal, Delft
    Gorenstein Dedecca, João
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Expansion Governance of the Integrated North Seas Offshore Grid2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The expansion of offshore power transmission and generation in the North Seas of Europe is accelerating rapidly. This is due to several drivers, including the decarbonization and reform of the European power system, and innovations in offshore wind and high-voltage direct current transmission. So far, this European North Seas offshore grid is composed of conventional transmission lines, which perform the interconnection of onshore power systems and the wind farm connection functions separately. An integrated offshore grid is an innovative concept where some of the transmission lines perform simultaneously both the interconnection and connection functions. Earlier research leveraging optimization approaches already demonstrated that such an integrated offshore grid can provide socio-economical, technical and environmental benefits.

    The offshore grid is characterized by its multiplicity of actors, working in several levels, from the European to the sub-national. This makes governance the only adequate decision-making mode to manage the grid expansion towards more integration. Governance combines hierarchies, markets and networks in order to guide decision-making in a networked multi-level, multi-actor system. The expansion governance of the offshore grid can be analyzed according to six building blocks: meta-governance, planning, financing, ownership, pricing and operation. Previous studies have identified important barriers in these building blocks for the development of an integrated offshore grid. These comprise the difficulties in the site planning and development of integrated projects, the allocation of costs and benefits among actors, and the compatibilization of national support schemes to offshore wind.

    This research applies an exploratory approach to expansion governance to understand how the offshore grid can be managed towards more integration in the presence of these barriers. Therefore, it does not prescribe investments in specific offshore wind farms and transmission corridors. This approach combines energy systems modeling and regulatory analysis to focus on the management of investments in offshore assets, which are central to developing an integrated grid.

    The Offshore Grid Exploratory Model (OGEM) was developed in this thesis to endogenously represent integrated governance barriers: the complexity of planning integrated lines and the interests of individual North Seas countries. OGEM confirms that an integrated offshore grid is beneficial to Europe. However, these benefits are highly dependent on the e-Highway2050 scenarios used, and asymmetrically distributed between countries and actor groups. Governance barriers (represented as model constraints) lead to a modest reduction in benefits, and do not change the distribution asymmetry.

    The impact of the barriers is more pronounced regarding investment changes in transmission technologies and integrated lines. They increase path dependence and hinder the deployment of multiterminal HVDC lines. Also, the location and potential of offshore wind interacts with investments in offshore transmission, both of which can change radically in the presence of governance barriers.

    The impact of these barriers on the offshore expansion pathways allows to recommend design principles for governance frameworks of offshore investments. These comprise the need for: a comprehensive expansion candidate portfolio including both non-integrated multiterminal HVDC and integrated projects; to consider the interrelation of expansion periods in planning; and to consider different rates of innovation for transmission technologies.

    In parallel, the Clean Energy Package is analyzed for the changes they bring to the European regional governance of offshore expansions. Five challenges are identified. The first two deal with the interaction of the governance structure of the European and national levels with the regional one. Then, the third challenge deals with the participation of the United Kingdom and Norway in the European expansion governance. On the other hand, the las two challenges concern specific governance building blocks. The planning challenge indicates that the regional planning of the offshore grid is dependent on national development plans, which in their turn must consider national interests. And the pricing and financing challenge indicates that cost allocation for Projects of Common Interest rigidly precedes the application for financing, invalidating the cost allocation in case the application is unsuccessful. Importantly, these challenges are largely unaddressed by the Energy Union reform.

    The thesis concludes with a number of policy recommendations. They concern meta-governance and the need for capacity building at the regional level. Then, multiple recommendations cover planning. Beyond following the design principles above, the planning challenge needs to be solved. Also, planning models and data should move towards open-modeling approaches which would facilitate the consideration of a broader candidate portfolio. Regarding financing and pricing, the regulation should foster more anticipatory investments than the current practice, and the Projects of Common Interest cost allocation and funding challenge should be solved. These recommendations constitute specific changes to the European expansion governance which would significantly improve the playing field for an integrated offshore grid.