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  • Public defence: 2018-03-21 13:30 hörsal F3, Stockholm
    Li, Nan
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Smart Cooperation with Network Coding in Hierarchical Wireless Networks2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    To achieve more dynamic, efficient and intelligent use of the scarce wireless spectrum resource, the concept of cooperation has been formalized into several hierarchical network models in future mobile networks. Cooperative communications, such as relaying, can potentially increase communication efficiency and spectrum utilization due to the broadcast nature of wireless networks, and may lead to a better support for diverse communication modes with flexible spectrum sharing. In this thesis, we investigate the cooperation between users with different priorities in hierarchical wireless networks. Especially, by coinciding the idea of relaying and network coding, we explore cooperation schemes from several aspects.

    First we discuss orthogonal time-frequency access for cooperation between primary and secondary users in a cognitive radio network, where two binary network coding schemes are developed. We analyze the transmission process and propose a novel methodology for performance evaluation. Second we propose a selective cooperation mechanism for intelligent resource sharing. By evaluating the system throughput with the approxiamtion method, we further discuss the spectrum sharing strategy by formulating an optimization problem to maximize the secondary system throughput. Besides, we extend our model to larger cognitive radio networks with multiple primary/secondary users. Finally we investigate non-orthogonal multiple access combined with orthogonal multiple access with hierarchical users. We define and study two cooperation schemes, where we derive the achievable rate regions with diverse communication modes supported. We formulate a problem jointly optimizing the strategy on time sharing and transmit power allocation at transmitters.

    Throughout the thesis we progressively reveal the importance of smart cooperation in hierarchical wireless networks, through rendering our models more realistic with smart strategies.

  • Public defence: 2018-03-22 13:00 T1, Huddinge
    Askfors, Ylva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics.
    Samverkan för innovation: En fallstudie av mötet mellan akademi, industri och sjukvård2018Doctoral thesis, monograph (Other academic)
    Abstract [sv]

    Samverkan kan leda till innovation, konkurrenskraftiga företag, förstklassig forskning samt välfungerande myndigheter och institutioner. I den politiska debatten idag finns en förväntan att Sverige ska upprätthålla sin konkurrenskraft och bemöta samhällets utmaningar genom innovation och att vägen till innovation går via samverkan. Avhandlingen bygger på en studie av ett samverkansprojekt vars syfte var att skapa innovation för att minska antalet vårdrelaterade infektioner i Sverige. Projektet som studerats ses som en transdisciplinär ansats med aktörer som representerade akademi, industri samt hälso- och sjukvård.

    Syftet med avhandlingen är att vidareutveckla kunskapen om interorganisatorisk samverkan för innovation. Detta görs genom ett tredelat bidrag, till teoribildningen kring samverkan för innovation som börjat växa fram, till den samverkande praktiken inom både privat och offentlig sektor samt till politiker och beslutsfattare som styr fördelning av statliga anslag till forskning och innovation.

    Fallstudien som ligger till grund för avhandlingen är baserad på en etnografiskt inspirerad studie. Empiriskt material samlades in och skapades tillsammans med aktörerna i projektet under drygt två års tid genom intervjuer och deltagande observation.

    Studien visar att interorganisatorisk samverkan består av flera dimensioner och kan förstås på flera nivåer. Interorganisatorisk samverkan innebär inte bara att det är olika organisationer som ska göra en gemensam ansträngning. Organisationerna består av olika människor med olika discipliner och professioner vilka bygger på olika utgångspunkter och sätt att se på världen. Samverkan kan ses som ett sätt att fylla mellanrummen mellan organisationer istället för att bygga broar över gränser. I de organisatoriska mellanrummen kan aktörer från olika organisationer, med olika discipliner och professioner mötas utan institutionaliserade roller, i en receptiv kontext där innovation kan skapas.

  • Public defence: 2018-03-23 09:00 hörsal F3, Stockholm
    Liu, Du
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Orthonormal Motion-Adaptive Transforms for Image Sequences2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In this thesis, we propose and discuss a class of motion-adaptive transforms (MAT) to describe the temporal correlation in image sequences for compression. The temporal correlation is based on motion models, and undirected graphs are used to represent this correlation in image sequences. The transforms are adaptive to general motion fields. Hence, they avoid the predict-update mismatch of the classic block-motion lifting schemes in processing connected and disconnected pixels. Moreover, the proposed transforms are orthonormal for general motion field, and thus, they permit energy conservation and perfect reconstruction.

    As we represent the motion-connected signals by graphs, we introduce a graph-based covariance matrix model and use the associated eigenvector matrix for compression. As the proposed covariance model is closely related to the graph, the relation between the covariance matrix and theLaplacian matrix is studied and the associated eigenvector matrices are discussed. The class of MAT is constructed by using so-called scale factors.We show that the scale factors determine a relevant subspace of the signal representation.Hence, we propose a subspace-constrained transform, which achieves optimal energy compaction given the subspace constraint. On the other hand, the resulting basis vectors are signal dependent.

    To construct practical transforms without using covariance matrices, we consider two types of incremental transforms over graphs, namely the uni-directional orthogonal transform (Uni-OT) and the bidirectional orthogonal transform (Bi-OT). In addition, fractional-pel MAT is proposed to further extend the class of MAT. Our fractional-pel MAT can incorporate a general interpolation filter into the basis vectors, while offering perfect reconstruction, orthogonality, and improved coding efficiency.

  • Public defence: 2018-03-23 11:00 Madrid
    Mazidi, Peyman
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems. Comillas Pontifical University.
    From Condition Monitoring to Maintenance Management in Electric Power System Generation with focus on Wind Turbines2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    With increase in the number of sensors installed on sub-assemblies of industrial components, the amount of data collected is rapidly increasing. These data hold information in the areas of operation of the system and evolution of health condition of the components. Therefore, extracting the knowledge from the data can bring about significant improvements in the aforementioned areas.

    This dissertation provides a path for achieving such an objective. It starts by analyzing the data at the sub-assembly level of the components and creates four frameworks for analysis of operation and maintenance (O&M) for past, present and future horizons at the component level. These frameworks allow improvement in operation, maintenance planning, cost reduction, efficiency and performance of the industrial components. Next, the dissertation evaluates whether such models can be linked with system level analysis and how providing such a link could provide additional improvements for system operators. Finally, preventive maintenance (PM) in generation maintenance scheduling (GMS) in electric power systems is reviewed and updated with recent advancements such as connection to the electricity market and detailed implementation of health condition indicators into the maintenance models. In particular, maintenance scheduling through game theory in deregulated power system, for offshore wind farm (OWF) and an islanded microgrid (MG) are investigated.

    The results demonstrate improvements in reducing cost and increasing profit for the market agents and system operators as well as asset owners. Moreover, the models also deliver an insight on how direct integration of the collected operation data through the developed component level models can assist in improving the operation and management of maintenance for the system.

  • Public defence: 2018-03-23 14:00 Kollegiesalen, Stockholm
    Della Penda, Demia
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Device-to-Device Communication in Future Cellular Networks: Resource allocation and mode selection2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The widespread use of smart devices and mobile applications is leading to a massive growth of wireless data traffic. Supporting the upcoming demands of data volume, communication rate, and system capacity requires reconsideration of the existing network architecture. Traditionally, users communicate through the base station via uplink/downlink paths. By allowing device-to-device (D2D) communication, that is, direct transmission between the users, we can enhance both efficiency and scalability of future networks. In this thesis, we address some of the challenges brought by the integration of D2D communication in cellular systems, and validate the potential of this technology by means of proper resource management solutions. Our main contributions lie in the context of mode selection, power control, and frequency/time resource allocation mechanisms. First, we investigate how the integration of D2D communication in dynamic Time Division Duplex systems can enhance the energy efficiency. We propose a joint optimization of mode selection, uplink/downlink transmission time, and power allocation to minimize the energy consumption. The optimization problem is formulated as a mixed-integer nonlinear programming problem, which is NP-hard in general. By exploiting the problem structure, we develop efficient (and for some scenarios, optimal) solutions. We complement the work with a heuristic scheme that achieves near-optimal solutions while respecting practical constraints in terms of execution times and signaling overhead. Second, we study the performance of several power control strategies applicable to D2D-enabled networks. In particular, we compare 3GPP LTE uplink power control with a distributed scheme based on utility maximization. Furthermore, to extend the application of well-known power control approaches to Rician-fading environments, we propose a power allocation scheme based on the concept of coherent-measure-of-risk. This approach allows to obtain a convex and efficiently solvable problem. Third, we study the subcarrier allocation problem in D2D-enabled networks. We maximize the total transmission rate by modeling the problem as a potential game. Nash equilibria of the game correspond to local optima of the objective function, which are found via better-response dynamic implemented with message passing approach. Finally, we propose two different applications of full-duplex technology for D2D communication. First, we present a practical mode selection algorithm that leverages only the existing control signaling to minimize the users' probability of outage. Second, we investigate how the combination of D2D relaying and full-duplex operations can improve the network coverage and the communication quality without additional infrastructure deployment.

  • Public defence: 2018-03-26 10:00 F3, Stockholm
    Ehteshami, Hossein
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Finite temperature properties of elements and alloy phases from first principles2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    First principles calculations are usually concerned with properties calculated at temperature 0 K. However, the industrially important materials are functioning at finite temperatures. To fill such a gap a first-principles based modeling of free energy has been developed in this thesis and finite temperature properties of different phases of Fe and Mn have been calculated and contrasted with available experimental data.

    In particular, using partitioning of the Helmholtz free energy, thermophysical properties of paramagnetic Fe have been reported. The heat capacity, lattice constant, thermal expansion and elastic moduli of γ- and δ-Fe show a good agreement with available experimental data. In the case of α-Fe, we observe a good agreement for elastic moduli and thermal expansion with experiments but the heat capacity is not well-reproduced in the calculations because of the large contribution of magnetic short-range which our models are not capable of capturing.

    α- and β-Mn theoretically pose a challenge for direct simulations of thermodynamic properties because of the complexity of magnetic and crystal structure. The partitioning of free energy has been used and thermodynamics of these phases have been derived. The obtained results show a good agreement with experimental data suggesting that, despite the complexities of these phases, a rather simple approach can well describe their finite temperature properties. High temperature phases of Mn, γ and δ, are also theoretically challenging problems. Employing a similar approach to Fe, thermophysical properties of these high symmetry phases of Mn have been reported which also show good agreement with available experimental data.

    The point defect and metal-self diffusion in titanium carbide (TiC), a refractory material, have been investigated in the present work. The common picture of metal-vacancy exchange mechanism for metal self-diffusion was shown to be unable to explain the experimentally observed values of activation energy. Several new clusters of point defects such as vacancies and interstitials have been found and reported which are energetically lower that a single metal vacancy. In a subsequent study, we showed that some of these clusters can be considered as mediators of metal self-diffusion in TiC.

    Evaluation of structural properties of Ti(O,C), a solid solution of TiC and β-TiO, from supercell approach is an extremely difficult task. For a dilute concentration of O, we show the complexity of describing an impurity of O in TiC using supercell approach. A single-site method such as the exact muffin-tin orbital method in the coherent potential approximation (EMTO-CPA) is a good alternative to supercell modeling of Ti(O,C). However, a study of Ti(O,C) using EMTO-CPA requires a further development of the technique regarding the partitioning of space. The shape module of EMTO has been modified for this purpose. With the help of the modified module, Ti(O,C) have been studied using EMTO-CPA. The results for the divacancy concentration and corresponding lattice parameter variations show good agreement with experimental data.

  • Public defence: 2018-03-26 13:30 air/fire at SciLifeLab, Solna
    Silverstein, David N.
    KTH, School of Electrical Engineering and Computer Science (EECS), Computational Science and Technology (CST).
    Investigations of neural attractor dynamics in human visual awareness2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    What we see, how we see it and what emotions may arise from stimuli has long been studied by philosophers, psychologists, medical doctors and neuroscientists. This thesis work investigates a particular view on the possible dynamics, utilizing computational models of spiking neural attractor networks. From neurological studies on humans and other primates, we know visual perception and recognition of objects occur partly along the visual ventral stream, from V1 to V2, V4, IT and downstream to other areas. This visual awareness can be both conscious and unconscious and may also trigger an emotional response. As seen from many psychophysical experiments in backward masking (BM) and attentional blink (AB), some spatial and temporal dynamics can determine what becomes visually conscious and what does not. To explore this computationally, biophysical models of BM and AB were implemented and simulated to mimic human experiments, with the assumption that neural assemblies as attractor networks activate and propagate along the ventral stream and beyond. It was observed that attractor interference between percepts in sensory and associative cortex can occur during this activity. During typical human AB experimental trials in which two expected target symbols amongst distractors are presented less than 500 ms apart, the second target is often not reported as seen. When simulating this paradigm as two expected target neural attractors amongst distractors, it was observed in the present work that an initial attractor in associative cortex can impede the activation and propagation of a following attractor, which mimics missing conscious perception of the second target. It was also observed that simulating the presence of benzodiazepines (GABA agonists) will slow cortical dynamics and increase the AB, as previously shown in human experiments.

    During typical human BM experimental trials in which a brief target stimulus is followed by a masking stimulus after a short interval of less than 100 ms, recognition of the target can be impaired when in close spatial proximity. When simulating this paradigm using a biophysical model of V1 and V2 with feedforward and feedback connections, attractor targets were activated in V1 before imposition of a proximal metacontrast mask. If an activating target attractor in V1 is quiesced enough with lateral inhibition from a mask, or not reinforced by recurrent feedback from feedforward activation in V2, it is more likely to burn out before becoming fully active and progressing through V2 and beyond. BM was also simulated with an increasing stimulus interval and with the presence and absence of feedback activity. This showed that recurrent feedback diminishes BM effects and can make conscious perception more likely.

    To better understand possible emotional components of visual perception and early regulation, visual signaling pathways to the amygdala were investigated and proposed for emotional salience and the possible onset of fear. While one subcortical and likely unconscious pathway (before amydala efferent signaling) was affirmed via the superior colliculus and pulvinar, four others traversed through the ventral stream. One traversed though IT on recognition, another via the OFC on conditioning, and two other possibly conscious pathways traversed though the parietal and then prefrontal cortex, one excitatory pathway via the ventral-medial area and one regulatory pathway via the ventral-lateral area. Predicted latencies were determined for these signaling pathways, which can be experimentally testable. The conscious feeling of fear itself may not occur until after interoceptive inspection.

    A pathology of attractor dynamics was also investigated, which can occur from the presence of a brain tumor in white matter. Due to degradation from tumor invasion of white matter projections between two simulated neocortical patches, information transfer between separate neural attractors degraded, leading first to recall errors and later to epileptic-like activity. Neural plasticity could partially compensate up to a point, before transmission failure. This suggests that once epileptic seizures start in glioma patients, compensatory plasticity may already be exhausted. Interestingly, the presence of additional noise could also partially compensate for white matter loss.

  • Public defence: 2018-03-28 09:00 F3, stockholm
    Ekane, Nelson
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies. KTH, Stockholm.
    ‘Making Sanitation Happen’: An Enquiry into Multi-Level Sanitation Governance2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The importance of sanitation for human health and development is undisputed. Sanitation is now high on the international development agenda and has become a salient issue in most developing countries, Rwanda and Uganda being no exception. However, there are still shortcomings as regards ‘making sanitation happen’ on the ground. The basic institutional environment and the right governance structures are yet to be fully put in place. This is even more important in the new modes of governance wherein increasing numbers of public, private, and philanthropic actors at different levels of society are involved in sanitation provision and hygiene promotion driven largely by global goals and international development agendas. This has engendered top-down pressure to meet prescribed targets which in most cases miss the complexity of context, distort service priorities, and in some cases compromise sustainability.

    This thesis disentangles how sanitation policies are articulated at multiple levels of governance and among various actors in the sector, and eventually translate into investment and behaviour change at the community and household levels. This is done by examining sanitation governance structures in Rwanda and Uganda. Specific emphasis is placed on the actors and actions at national, sub-national, community and household levels.

    Drawing on multi-level governance as a conceptual framework, qualitative analysis of policy objectives and choices, and quantitative investigations of what motivates hygiene behaviour change at the community and individual levels, this cross-national comparative study is a novel attempt to decipher the complexity surrounding sanitation and to show ‘what makes sanitation happen’.

    The insights of this research build on different strands of the literature but most importantly they contribute to the debate in the sanitation sector on what works on the ground, why and where.


  • Public defence: 2018-04-06 13:00 FB53, Stockholm
    Parfeniukas, Karolis
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    High-Aspect Ratio Nanofabrication for Hard X-Ray Zone Plates2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Hard x-ray nanoimaging enables structural investigations of new materials for many applications. For high-resolution experiments, zone plate x-ray optics are commonly chosen.Two methods of zone plate nanofabrication are presented in this thesis.

    Zone plates are circular diffraction gratings with radially decreasing grating period. Their optical resolution depends on the width of the smallest zone, which nowadays can be around 10 nanometers. However, the efficiency of a zone plate depends on its thickness and its material. For hard x-rays, the optimal zone plate thickness is in the order of micrometers. Therefore, high aspect ratio nanofabrication processes are needed.Two such methods are investigated in this study.

    First, an existing tungsten nanofabrication process based on reactive ion etching (RIE) was extended to 22:1 aspect ratio structures at 30~nm line width. The core improvement was a resist curing step that enhanced pattern transfer during RIE. Such a zone plate with 200 micrometer diameter and 2.2% efficiency was used in the commissioning experiment of NanoMAX, the nanoimaging beamline at the Swedish synchrotron facility MAX IV. Transmission imaging with 40 nm resolution, as well as the fluorescence imaging modality were demonstrated.

    Second, metal-assisted chemical etching (MACE) of silicon using gold catalyst patterns was investigated. MACE dependence on gold pattern geometry, etching solution composition, temperature, and substrate doping is described. The process is characterized in terms of etching rate, directionality, and nanostructure surface roughness.

    Finally, the Ronchi test is presented as a way to quickly judge the performance of x-ray optics in terms of present aberrations and x-ray sources in terms of coherence.

  • Public defence: 2018-04-06 13:15 Sal B, Kista, Stockholm
    Hjort Blindell, Gabriel
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS. KTH, School of Electrical Engineering and Computer Science (EECS). RISE SICS.
    Universal Instruction Selection2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In code generation, instruction selection chooses instructions to implement a given program under compilation, global code motion moves computations from one part of the program to another, and block ordering places program blocks in a consecutive sequence. Local instruction selection chooses instructions one program block at a time while global instruction selection does so for the entire function. This dissertation introduces a new approach called universal instruction selection that integrates global instruction selection with global code motion and block ordering. By doing so, it addresses limitations of existing instruction selection techniques that fail to exploit many of the instructions provided by modern processors.

    To handle the combinatorial nature of these problems, the approach is based on constraint programming, a combinatorial optimization method. It relies on a novel model that is simpler and more flexible compared to the techniques used in modern compilers and that captures crucial features ignored by other combinatorial approaches. The dissertation also proposes extensions to the model for integrating instruction scheduling and register allocation, two other important problems of code generation.

    The model is enabled by a novel, graph-based representation that unifies data and control flow for entire functions. The representation is crucial for integrating instruction selection with global code motion and for modeling sophisticated instructions, whose behavior contains both data and control flow, as graphs.

    Through experimental evaluation, universal instruction selection is demonstrated to handle architectures with a rich instruction set and scales up to functions with hundreds of operations. For these functions, it generates code of equal or better quality compared to the state of the art. The dissertation also demonstrates that there is sufficient data parallelism to be exploited through selection of SIMD instructions and that this exploitation benefits from global code motion. With these results, it is argued that constraint programming is a flexible, practical, competitive, and extensible approach for combining global instruction selection, global code motion, and block ordering.

  • Public defence: 2018-04-12 10:00 F3, Stockholm
    Li, Wei
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    PMU-based State Estimation for Hybrid AC and DC Grids2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Power system state estimation plays key role in the energy management systems(EMS) of providing the best estimates of the electrical variables in the grid that arefurther used in functions such as contingency analysis, automatic generation control,dispatch, and others. The invention of phasor measurement units (PMUs) takes thepower system operation and control into a new era, where PMUs’ high reportingrate and synchronization characteristics allow the development of new wide-areamonitoring, protection, and control (WAMPAC) application to enhance the grid’sresiliency. In addition, the large number of PMU installation allows the PMU-onlystate estimation, which is ready to leap forward today’s approach which is based onconventional measurements.At the same time, high voltage direct current (HVDC) techniques enable totransmit electric power over long distance and between different power systems,which have become a popular choice for connecting variable renewable energy sourcesin distant locations. HVDCs together with another type of power electronic-baseddevices, flexible AC transmission system (FACTS), have proven to successfullyenhance controllability and increase power transfer capability on a long-term costeffectivebasis. With the extensive integration of FACTS and HVDC transmissiontechniques, the present AC networks will merge, resulting in large-scale hybrid ACand DC networks. Consequently, power system state estimators need to considerDC grids/components into their network models and upgrade their estimationalgorithms.This thesis aims to develop a paradigm of using PMU data to solve stateestimations for hybrid AC/DC grids. It contains two aspects: (i) formulating thestate estimation problem and selecting a suitable state estimation algorithm; (ii)developing corresponding models, particularly for HVDCs and FACTS.This work starts by developing a linear power system model and applying thelinear weighted least squares (WLS) algorithm for estimation solution. Linear networkmodels for the AC transmission network and classic HVDC links are developed. Thislinear scheme simplifies the nonlinearities of the typical power flow network modelused in the conventional state estimations and has an explicit closed-form solution.However, as the states are voltage and current phasors in rectangular coordinates,phasor angle is not an explicit state in the modeling and estimation process. Thisalso limits the linear estimators’ ability to deal with the corrupt angle measurementsresulting from timing errors or GPS spoofing. Additionally, it is cumbersome toselect state variables for an inherently nonlinear network model, e.g., classic HVDClink, when trying to fulfill its linear formulation requirement.In contrast, it is more natural to use PMU measurements in polar coordinatesbecause they can provide an explicit state measurement set to be directly used inthe modeling and estimation process without form changes, and more importantly,it allows detection and correction for angle bias which emerges due to imperfectsynchronization or incorrect time-tagging by PMUs. To this end, the state estimationproblem needs to be formulated as a nonlinear one and the nonlinear WLS is applied for solution. We propose a novel measurement model for PMU-based state estimationwhich separates the errors due to modeling uncertainty and measurement noise sothat different weights can be assigned to them separately. In addition, nonlinearnetwork models for AC transmission network, classic HVDC link, voltage sourceconverter (VSC)-HVDC, and FACTS are developed and validated via simulation.The aforementioned linear/nonlinear modeling and estimation schemes belongto static state estimator category. They perform adequately when the system isunder steady-state or quasi-steady state, but less satisfactorily when the system isunder large dynamic changes and the power electronic devices react to these changes.Testing results indicate that additional modeling details need to be included toobtain higher accuracy during system dynamics involving fast responses from powerelectronics. Therefore, we propose a pseudo-dynamic modeling approach that canimprove estimation accuracy during transients without significantly increasing theestimation’s computational burden. To illustrate this approach, the pseudo-dynamicnetwork models for the static synchronous compensator (STATCOM), as an exampleof a FACTS device, and the VSC-HVDC link are developed and tested.Throughout this thesis, WLS is the main state estimation algorithm. It requiresa proper weight quantification which has not been subject to a sufficient attentionin literature. In the last part of thesis, we propose two approaches to quantify PMUmeasurement weights: off-line simulation and hardware-in-the-loop (HIL) simulation.The findings we conclude from these two approaches will provide better guidancefor selecting proper weights for power system state estimation.

  • Public defence: 2018-04-13 10:00 FR4 Oskar Kleins Auditorium, Stockholm
    Lindbo, Sarah
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Protein Technology.
    Generation and engineering of ABD-derived affinity proteins for clinical applications2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Proteins that specifically recognize and bind to other molecules or structures are important tools in industrial and medical applications. Binding proteins engineered from small stable scaffold proteins have been utilized for several purposes due to their favorable biophysical properties, tolerance to mutagenesis, efficient tissue penetration and ease of production. The 46 amino acid long albumin-binding domain (ABD) derived from the bacterial receptor Protein G is a promising scaffold that has been explored in this thesis. The scaffold was subjected to combinatorial protein engineering for generation of ABD-derived binding proteins with novel specificities. Furthermore, the medical potential of engineered ABD- derived affinity proteins (ADAPTs) was evaluated in a series of pre-clinical studies.

    In the first studies, ADAPTs suitability as tracers for radionuclide molecular imaging was evaluated. Factors influencing biodistribution and tumor targeting properties were assessed in mice models bearing HER2 positive xenografts. All tested ADAPT constructs demonstrated high and specific targeting of HER2-expressing tumor cells as well as fast clearance from circulation. The results also showed that the size and character of the N- terminus affected the biodistribution profile of ADAPTs. Moreover, the targeting properties of ADAPTs proved to be highly influenced by the residualizing properties of the attached radionuclide label. Taken together, the results provided the first evidence that tumor imaging can be performed using ADAPTs and the favorable pharmacokinetic profiles in the studied mice models suggest that the scaffold is a promising candidate for clinical applications.

    In the last study, a platform for generation of stable ABD-derived affinity proteins with novel binding specificities was established using a multi-step approach combining directed evolution and rational protein design. A broad combinatorial protein library with 20 randomized positions in ABD was designed and binders against three distinct targets were selected using phage display. Characterization of the selected binders provided information regarding optimal positions to randomize in a final library. In addition, the isolated binders were subjected to mutagenesis in certain surface exposed positions and mutations that provided increased stability were introduced into the original scaffold. Finally, a more focused combinatorial protein library consisting of 11 randomized positions was designed and constructed. The library was validated by selections against the same set of targets as for the first, broad library. The isolation of highly stable affinity ligands confirms that the library can be used for generation of diverse and stable affinity molecules.

  • Public defence: 2018-04-20 13:30 Architecture School, A108, Stockholm
    Karami, Sepideh
    KTH, School of Architecture and the Built Environment (ABE), Architecture, Critical Studies in Architecture.
    Interruption: Writing a Dissident Architecture2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Interruption: Writing a Dissident Architecture makes a contribution to the fields of writing architecture and dissident architecture. Concerned with developing an ethos of criticality from within, it presents a series of performative writing experiments that are situated in politically charged architectural sites, from public spaces, to institutions, to domestic spaces. My aim is to ask how a dissident architecture could be produced through the practice of writing, specifically by offering an account of the performative acts of various characters who are introduced in the thesis, and who critically inhabit existing architectural sites, interrupt the spatial power relations of those sites, and who thereby construct 'performing grounds'.

    Writing architecture is developed in this thesis not as writing about architecture, but aims instead to write it, to make it. Writing dissident architecture writes with multiple voices, with many authors, not all of whom are welcomed. It offers significant approaches to a political and critical understanding of architecture. Where architecture in this thesis is understood both as a material structure and as a disciplinary framework in which power can become oppressive, writing architecture, on the other hand, is developed as a ‘minor’ practice that can act upon existing sites, interrupting their ‘major’ power relations. Interruption, developed as a tactic, is what activates architecture to become a performing ground for the act of dissidence. 

    Formulated as a journey the three main parts of the thesis deal with three interrupting tactics: Pause, Cut and Fo(o)l+d, which are applied in relation to three different kinds of political site: 1) spaces of appearance or the spectacle; 2) disciplined spaces understood as sites of impossibility; 3) domestic spaces as displaced loci of subversive political actions. The Pause uses stillness and refusal as a mode of interruption. The Cut interrupts the material and structural continuity of established institutions and creates cracks in those systems. The Fo(o)l+d interrupts surveillance and control by folding in and out of private and public spaces. By introducing a quasi-fictional character to each site, who performs through one of the three tactics of interruption, a performing ground is constructed. Writing architecture forwards this journey across specific sites through which the figure of the dissident emerges.