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  • Disputas: 2018-06-05 10:15 F104, Trollhättan
    Mahade, Satyapal
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT).
    Functional Performance of Gadolinium Zirconate/Yttria Stabilized Zirconia Multi-Layered Thermal Barrier Coatings2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Yttria stabilized zirconia (YSZ) is the state-of-the-art ceramic top coat material used for thermal barrier coating (TBC) applications. Demand for higher efficiency in gas turbine engines has led to a continuous increase in the gas in let temperature. However, this increase in temperature has pushed YSZ to its upper limit. Above1200 °C, issues such as poor phase stability, high sintering rate, and susceptibility to CMAS (Calcium Magnesium Alumino Silicates) degradation limit the durability of YSZ based TBCs. Among the new top coat materials suggested for high temperature TBC applications, gadolinium zirconate (GZ) is an interesting alternative to YSZ since it has shown attractive properties which include a better resistance to CMAS attack. However, GZ has poor thermo-chemical compatibility with the thermally grown oxide (alumina), leading to poor thermalcyclic fatigue performance of single layered GZ TBCs. Therefore, a multi-layered GZ/YSZ based TBC design seems promising. This work presents a new approach of depositing multi-layered (double and triple layered) GZ/YSZ TBCs using the recently developed suspension plasma spray(SPS) process. SPS was employed in this work because of its capability to mimic the electron beam physical vapour deposition (EB-PVD) process in terms of producing columnar microstructured TBCs. Single layer YSZ TBCs were also deposited by SPS process and used as a reference for comparing the functional performance of multi-layered GZ based TBCs. The primary aim of this work was to improve the durability of GZ based multilayered TBCs at high temperatures. Durability tests were performed in the temperature range 1100 °C - 1400 °C under different thermal cyclic test conditions (with and without thermal gradient). The results indicate that multilayered GZ based TBCs improve durability compared to the single layer YSZTBCs at all the test temperatures. Failure analysis of the multi-layered GZ/YSZTBCs revealed spallation within the GZ layer close to GZ/YSZ interface and the reason was believed to be the inferior fracture toughness of GZ. In order to improve the fracture toughness in the region of failure, a composite approach comprising multi-layered GZ+YSZ based TBC was considered. It was shown that the composite GZ+YSZ based TBCs did not improve the thermal cyclic lifetime, although improvement in fracture toughness was observed. As a further extension of this work, the influence of YSZ layer thickness on the durability of GZ/YSZTBCs was investigated. It was shown that an increase in YSZ layer thickness in the GZ/YSZ TBC led to poor durability. Additionally, the other important performance criteria for TBCs, i.e. thermal conductivity, was measured experimentally and compared with the single layer YSZ TBC. It was shown that the GZ based TBCs had lower thermal conductivity than YSZ. The second aim was to investigate and compare the erosion performance of multi-layered GZ based TBCs and single layered YSZ TBCs. In the erosion testconducted at room temperature, the GZ based TBCs showed lower erosion resistance compared to the single layer YSZ TBC. The main reason for this difference was attributed to the inferior fracture toughness of GZ. In case of the composite multi-layered GZ+YSZ based TBC, an improvement in erosion resistance was observed compared to the multi-layered GZ based TBC. Based on the results obtained, this work has demonstrated that SPS is a promising processing technique to produce columnar microstructured TBCs irrespective of the composition (GZ, YSZ, GZ+YSZ). It was also shown that GZ/YSZ multilayered TBCs are promising for high temperature TBC applications due to theirl ow thermal conductivity and high thermal cyclic fatigue lifetime. However, low erosion resistance for certain applications might be an issue for the GZ basedTBCs.

  • Disputas: 2018-06-07 09:15 Auditorium Minus, Uppsala
    Löscher, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datalogi.
    Targeted Property-Based Testing with Applications in Sensor Networks2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Testing is a fundamental part of modern software development, as it unveils bugs in the system under test and gives confidence in their correctness. Testing is often a laborious task as it typically requires to write by hand a plethora of test cases to test a system thoroughly. This task can be aided by high-level testing techniques such as random property-based testing (PBT) where the testing task is reduced to specifying properties that the system under test is expected to satisfy, and generators that produce well-distributed random inputs to these properties. However, as with all random testing techniques, the confidence in the system and the chances of finding a bug is proportional to the number of tests. If the set of possible inputs is large, even a high number of tests does not yield a satisfactory result. One example is testing sensor networks, where one not only needs to produce the inputs for the software system but also needs to consider the network topology and the systems environment.

    This dissertation presents targeted property-based testing, an enhanced form of PBT where the input generation is guided by a search strategy instead of being random, thereby combining the strengths of QuickCheck-like and search-based testing techniques. It furthermore presents an automation for the simulated annealing search strategy that reduces the manual task of using targeted PBT. We present concrete implementations for all presented techniques and a framework for PBT of sensor networks.

    Applying PBT to testing sensor networks has allowed us to test relatively complex software and uncover subtle and hard-to-find bugs. We evaluate targeted PBT by comparing it to its random counterpart on a series of case studies. We show that its testing performance is significantly higher than that of random PBT. Furthermore, we demonstrate that the extra effort required to use targeted PBT is limited to specifying a test goal. With these results, we argue that targeted PBT improves the state-of-the-art of software testing and ultimately leads to higher confidence in complex software systems.

  • Disputas: 2018-06-07 10:15 Room 13:026, Uppsala
    Guath, Mona
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Feedback learning and multiple goal pursuit in an electricity consumption task2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The overall aim with the thesis was to investigate how learning to pursue two conflicting goals (cost and utility) in an electricity consumption task is affected by different forms of feedback, goal phrasing, and task environment. Applied research investigating the efficiency of outcome feedback on electricity consumption via in-home displays points at modest reductions (2-4%). Further, a wealth of cognitive psychological research shows that learning with outcome feedback is not unproblematic. A new experimental paradigm, the simulated household, that captures the cognitive task that confronts people when trying to regulate their electricity consumption, was developed. In three studies, different aspects of the problem of regulating one’s consumption was investigated. Study I, investigated how different feedback in terms of frequency, detail, and presence of random noise or not affect performance. It also investigated if participants pursued the goals sequentially or simultaneously and if they were able to derive a model of the task. Results showed that frequent feedback was beneficial only in a deterministic system and, surprisingly, random noise improved performance by highlighting the most costly appliances. Modelling results indicated that participants pursued goals sequentially and did not have a mental model of the task. Study II, investigated if a short feedforward training could replace or complement outcome feedback. Results indicated that the performance with one of the feedforward training schemes lead to comparable performance to outcome feedback only. The best performance was obtained when this feedforward scheme was combined with outcome feedback. Study III, investigated if the sequential goal pursuit observed in Study I was related to interpretation of the task or cognitive limitations by specifying goals for cost and/or utility. Further, it investigated the reason for the cost prioritisation. Results indicated that the sequential goal pursuit derives from cognitive constraints. Together, the results from the studies suggest that people pursue the goals sequentially and that instant outcome feedback may harm performance by distracting people from the most important and costly appliances to the appliances that allow large variability in use.

  • Disputas: 2018-06-01 10:00 Kalmar
    Davidsson, Marita
    Linnéuniversitetet, Fakulteten för samhällsvetenskap (FSV), Institutionen för pedagogik (PED).
    Värdeladdade utvärderingar: en diskursanalys av förskolors systematiska kvalitetsarbete2018Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The overarching interest of this licentiate thesis is directed towards values as they are discursively constructed in systematic quality work in preschool. The aim of the study is to contribute with knowledge about the values discursively expressed in systematic quality work in preschool and how these can, in turn, be understood in relation to current quality work contexts. Values, as understood in the study, are assumptions about something good, desirable and worth aiming at and are seen as socially constructed in a specific societal, cultural and historical context. Discourse can be interpreted as a certain way of talking about and understanding values where language represents a specific meaning context.

    Fairclough’s critical discourse analysis has been applied to critically examine and make visible what values and discourses are expressed in the systematic quality work in preschool, as well as their mutual relations. In addition, Ball’s performativity concept has been used. The empirical material consists of 17 preschools’ documented systematic quality work in the form of evaluations conducted during the 2014-2015 school year.

    The value practice emerging from the analysis of the evaluations carries a complexity in that values appear to overlap and may thus be hard to separate. Values are both explicitly and implicitly expressed. What is highlighted as desirable can be categorized within five areas: competence, democracy, ethics, disciplination and efficiency.

    The result shows that a goal rational, a market-oriented, a relational, a morally oriented and a development psychology discourse are included in the order of discourse that exercises power over the values that are expressible and over the way this is done. The analysis clearly demonstrates the predominance of the goal rational discourse, while the influence of the development psychology discourse seems to be limited with regard to what is considered desirable in the organization. It also emerges that there is a power structure where the goal rational and the market-oriented discourses seem to include and articulate the other discourses within the order of discourse.

    In a long-time perspective, preschool activities appear to have passed from development psychology rationality to goal rationality. For preschool children this transformation may have entailed that currently the strongly emphasized welfare aspect of the organization tends towards a strong emphasis on competence. These values stand out in the evaluations as two opposite poles, which may indicate a swing of the pendulum from one side to the other.

  • Disputas: 2018-06-13 10:00 Q2, Stockholm
    Gaborit, Mathieu
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. LAUM UMR CNRS 6613, Le Mans Université, Le Mans, France.
    Modelling of thin and imperfect interfaces: Tools and preliminary study2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    For quite some time, the strive for more efficient acoustic absorbers keepsincreasing, driven by a number of psycho-physiological studies on health re-lated dangers of noise exposure. As the global wealth increases and with itthe global expectation of quieter living and working environments, manifestedin both politics and research, an important market for sound absorbing andnoise control systems develops in all industrialised countries. In the acousticcommunity, the main endeavours of the two last decades have been orientedtowards a better understanding of the dissipation phenomena in absorbers(and especially in poroelastic media) as well as proposing new topologies andstructures for these elements. These efforts have resulted in an abundant lit-erature and numerous improvements of the characterisation, modelling anddesign methodologies for a wide range of media and many different systems.The chosen research direction for the present thesis slightly deviates fromthis usual path of modelling absorbing materials as bulk media. Here theaim is to investigate the interfaces between the different components of typ-ical absorbers. Indeed, these interface regions are known to be difficult tocharacterise and controlling their properties is challenging for a number ofreasons. Interfaces in sound packages for instance are inherently by-productsof the assembly process and, even if they surely have an important impact onthe acoustic performance, they remain mostly overlooked in the establishedmodelling practices. Therefore, the overall objective of the current doctoralproject is to identify strategies and methods to simulate the effect(s) of un-certainties on the interface physical or geometrical parameters.The present licentiate thesis compiles three works which together form adiscussion about techniques and tools designed in an attempt to efficientlymodel thin layers and small details in rather large systems. As part of thework a section of physical model simplifications is discussed which will laythe ground for the next stages of the research. Two publications on the firsttopic are included, presenting Finite-Element-based hybrid methods that al-low for coating elements in meta-poroelastic systems to be taken into accountand reduce the computational cost of modelling small geometric features em-bedded in large domains. The third included contribution is an anticipation,to a certain extent, of the remainder of the doctoral project, discussing theuse of physical heuristics to simplify porous thin film models. Here a steptowards the modelling of interface zones is taken, departing from numericalsimulations and reflecting instead on the physical description and modellingof thin poroelastic layers.

  • Disputas: 2018-06-13 10:00 Nash/Wardrop, Stockholm
    Johansson, Ingrid
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Transportplanering, ekonomi och teknik.
    Simulation Studies of Impact of Heavy-Duty Vehicle Platoons on Road Traffic and Fuel Consumption2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The demand for road freight transport continues to grow with the growing economy, resulting in increased fossil fuel consumption and emissions. At the same time, the fossil fuel use needs to decrease substantially to counteract the ongoing global warming. One way to reduce fuel consumption is to utilize emerging intelligent transport system (ITS) technologies and introduce heavy-duty vehicle (HDV) platooning, i.e. HDVs driving with small inter-vehicle gaps enabled by the use of sensors and controllers. It is of importance for transport authorities and industries to investigate the effects of introducing HDV platooning. Previous studies have investigated the potential benefits, but the effects in real traffic, both for the platoons and for the surrounding vehicles, have barely been explored. To further utilize ITS and optimize the platoons, information about the traffic situation ahead can be used to optimize the vehicle trajectories for the platoons. Paper I presents a dynamic programming-based optimal speed control including information of the traffic situation ahead. The optimal control is applied to HDV platoons in a deceleration case and the potential fuel consumption reduction is evaluated by a microscopic traffic simulation study with HDV platoons driving in real traffic conditions. The effects for the surrounding traffic are also analysed. Paper II and Paper III present a simulation platform to assess the effects of HDV platooning in real traffic conditions. Through simulation studies, the potential fuel consumption reduction by adopting HDV platooning on a real highway stretch is evaluated, and the effects for the other vehicles in the network are investigated.

  • Nordling, Sofia
    et al.
    Brännström, Johan
    Carlsson, Fredrik
    Lu, Bo
    Salvaris, Evelyn
    Wanders, Alkwin
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap.
    Buijs, Jos
    Estrada, Sergio
    Tolmachev, Vladimir
    Cowan, Peter J.
    Lorant, Tomas
    Magnusson, Peetra U.
    Enhanced protection of the renal vascular endothelium improves early outcome in kidney transplantation: peclinical investigations in pig and mouse2018Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, artikkel-id 5220Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ischemia reperfusion injury is one of the major complications responsible for delayed graft function in kidney transplantation. Applications to reduce reperfusion injury are essential due to the widespread use of kidneys from deceased organ donors where the risk for delayed graft function is especially prominent. We have recently shown that coating of inflamed or damaged endothelial cells with a unique heparin conjugate reduces thrombosis and leukocyte recruitment. In this study we evaluated the binding capacity of the heparin conjugate to cultured human endothelial cells, to kidneys from brain-dead porcine donors, and to murine kidneys during static cold storage. The heparin conjugate was able to stably bind cultured endothelial cells with high avidity, and to the renal vasculature of explanted kidneys from pigs and mice. Treatment of murine kidneys prior to transplantation reduced platelet deposition and leukocyte infiltration 24 hours post-transplantation, and significantly improved graft function. The present study thus shows the benefits of enhanced protection of the renal vasculature during cold storage, whereby increasing the antithrombotic and anti-adhesive properties of the vascular endothelium yields improved renal function early after transplantation.

  • Bågander, Linnea
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    BODY OF MOVEMENT - (IN)forming movement2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This work aims to suggest materialized expressions based the moving body. As a principle of design, it treats the body as a whole and focuses on the in-betweens that the body creates in movement as aesthetics, not looking at its surface or the traditional ways of dividing the body (e.g. sweater, pants).

    In conclusion, the results suggest that the body movement has a spatial continuation as dynamic space that can be materialized. It is a suggestion a principle of design that can be applied in fashion design, choreography, architecture, furniture design. 

  • Chen, Chen
    et al.
    Middleware System Research Group, University of Toronto.
    Tock, Yoav
    IBM Research - Haifa.
    Girdzijauskas, Sarunas
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    BeaConvey: Co-Design of Overlay and Routing for Topic-basedPublish/Subscribe on Small-World Networks2018Konferansepaper (Fagfellevurdert)
  • Skoog, Therese
    et al.
    Kimber, Birgitta
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap.
    Special issue: Social and Emotional Learning and Diversity2017Inngår i: The International Journal of Emotional Education, ISSN 2073-7629, E-ISSN 2073-7629, Vol. 9, nr 2, s. 1-3Artikkel i tidsskrift (Annet vitenskapelig)
  • Disputas: 2018-06-08 12:40 Room 19, Torino, Italia
    Samavati, Mahrokh
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Design and analysis of solid oxide electrolysis-based systems for synthetic liquid fuels production2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    During the past decades, considerable attention has been dedicated to renewable energy systems. This is due to the increased awareness regarding greenhouse gas emissions as well as limits of the future availability and reliability of conventional energy and power systems. Renewable energy can be considered as free, nearly infinite, and clean; however, such resources have their own drawbacks. Renewables face challenges in meeting instantaneous electricity demand and for utilization as transportation fuels. One of the main challenges of renewable energy sources like solar and wind is due to their variability, making them incapable of meeting the required energy demands at all the time. Therefore it is beneficial to add energy storage for handling supply and demand.

    The current study is dedicated to the design and analysis of an integrated system for production of synthetic fuels as a way of renewable energy storage. The proposed system integrates solid oxide electrolysis, entrained gasification, and Fischer-Tropsch process. The main product of system is Fischer-Tropsch diesel which is produced from steam, CO2, and different renewables, namely: lignocellulosic biomass, solar PV electricity, and wind electricity. This approach has the benefit of storing the excess electrical energy from renewables in the form of chemical energy of the hydrocarbon fuels for further usage during peak hours. Also, using these synthetic fuels results in an increase of the renewable energy share in the transportation system while utilizing existing distribution and conversion technologies.

    The proposed system is analyzed from thermodynamic, economic, and environment perspectives. This study addresses several different research questions, from finding the optimum operating condition of precursor syngas producing subsystems to evaluating the theoretical potential of integrated systems in different locations.

  • Disputas: 2018-06-13 13:00 A3: 1077, Stockholm
    Banerjee, Saikat
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kondenserade materiens teori.
    Interacting Dirac Matter2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The discovery of graphene in 2004 has led to a surge of activities focused on the theoretical and experimental studies of materials hosting linearly dispersive quasiparticles during the last decade. Rapid expansion in the list of materials having similar properties to graphene has led to the emergence of a new class of materials known as the Dirac materials. The low energy quasiparticles in this class of materials are described by a Dirac-like equation in contrast to the Schrödinger equation which governs the low energy dynamics in any conventional materials such as metals. The Dirac fermions, as we call these low-energy quasiparticles, in a wide range of materials ranging from the d-wave superconductors, graphene to the surface states of topological insulators share the common property. The particles move around as if they have lost their mass. This feature results in a completely new set of physical effects consisting of various transport and thermodynamic quantities, that are absent in conventional metals.

    This thesis is devoted to studying the properties of bosonic analogs of the commonly known Dirac materials where the quasiparticle are fermionic. In chapter one, we discuss the microscopic origin of the Dirac equation in several fermionic and bosonic systems. We observe identical features of the Dirac materials with quasiparticles of either statistics when the interparticle interaction is absent. Dirac materials with both types of quasiparticles possess the nodal excitations that are described by an effective Dirac-like equation. The possible physical effects due to the linear dispersions in fermionic and bosonic Dirac materials are also outlined.

    In chapter two, we propose a system of superconducting grains arranged in honeycomb lattice as a realization for Bosonic Dirac Materials (BDM). The underlying microscopic dynamics, which give rise to the emergence of Dirac structure in the spectrum of the collective phase oscillations, is discussed in detail. Similarities and differences of BDM systems to the conventional Dirac materials with fermionic quasiparticles are also mentioned. Chapter three is dedicated to the detailed analysis of the interaction effects on the stability and renormalization of the conical Dirac band structure. We find that the type of interaction dictates the possible fate of renormalized Dirac cone in both fermionic and bosonic Dirac materials. We study interaction effects in four different individual systems : (a) Dirac fermions in graphene interacting via Coulomb interactions, (b) Dirac fermions subjected to an onsite Hubbard repulsion, (c) Coulomb repulsion in charged Cooper pairs in honeycomb lattice and (d) Dirac magnons interacting via Heisenberg exchange interaction. The possibility of interaction induced gap opening at the Dirac nodal point described is also discussed in these cases.

    Chapter four mainly concerns the study of a related topic of the synthetic gauge fields. We discuss the possibility of Landau quantization in neutral particles. Possible experimental evidence in toroidal cold atomic traps is also mentioned. A connection to Landau levels in case of magnons is also described. We finally conclude our thesis in chapter five and discuss the possible future directions that can be taken as an extension for our works in interacting Dirac materials.

  • Gnanapragasam, V. J.
    et al.
    Bratt, O.
    Muir, K.
    Lees, L. S.
    Huang, H. H.
    Stattin, Pär
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi. Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
    Lophatananon, A.
    The Cambridge Prognostic Groups for improved prediction of disease mortality at diagnosis in primary non-metastatic prostate cancer: a validation study2018Inngår i: BMC Medicine, ISSN 1741-7015, E-ISSN 1741-7015, Vol. 16, artikkel-id 31Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The purpose of this study is to validate a new five-tiered prognostic classification system to better discriminate cancer-specific mortality in men diagnosed with primary non-metastatic prostate cancer.

    Methods: We applied a recently described five-strata model, the Cambridge Prognostic Groups (CPGs 1-5), in two international cohorts and tested prognostic performance against the current standard three-strata classification of low-, intermediate- or high-risk disease. Diagnostic clinico-pathological data for men obtained from the Prostate Cancer data Base Sweden (PCBaSe) and the Singapore Health Study were used. The main outcome measure was prostate cancer mortality (PCM) stratified by age group and treatment modality.

    Results: The PCBaSe cohort included 72,337 men, of whom 7162 died of prostate cancer. The CPG model successfully classified men with different risks of PCM with competing risk regression confirming significant intergroup distinction (p < 0.0001). The CPGs were significantly better at stratified prediction of PCM compared to the current three-tiered system (concordance index (C-index) 0.81 vs. 0.77, p < 0.0001). This superiority was maintained for every age group division (p < 0.0001). Also in the ethnically different Singapore cohort of 2550 men with 142 prostate cancer deaths, the CPG model outperformed the three strata categories (C-index 0.79 vs. 0.76, p < 0.0001). The model also retained superior prognostic discrimination in the treatment sub-groups: radical prostatectomy (n =3D 20,586), C-index 0.77 vs. 074; radiotherapy (n =3D 11,872), C-index 0.73 vs. 0.69; and conservative management (n =3D 14,950), C-index 0.74 vs. 0.73. The CPG groups that sub-divided the old intermediate-risk (CPG2 vs. CPG3) and high-risk categories (CPG4 vs. CPG5) significantly discriminated PCM outcomes after radical therapy or conservative management (p < 0.0001).

    Conclusions: This validation study of nearly 75,000 men confirms that the CPG five-tiered prognostic model has superior discrimination compared to the three-tiered model in predicting prostate cancer death across different age and treatment groups. Crucially, it identifies distinct sub-groups of men within the old intermediate-risk and high-risk criteria who have very different prognostic outcomes. We therefore propose adoption of the CPG model as a simple-to-use but more accurate prognostic stratification tool to help guide management for men with newly diagnosed prostate cancer.

  • Disputas: 2018-06-07 14:00 Hörsal K2, Stockholm
    Stefanov, Kalin
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Tal, musik och hörsel, TMH.
    Recognition and Generation of Communicative Signals: Modeling of Hand Gestures, Speech Activity and Eye-Gaze in Human-Machine Interaction2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Nonverbal communication is essential for natural and effective face-to-face human-human interaction. It is the process of communicating through sending and receiving wordless (mostly visual, but also auditory) signals between people. Consequently, a natural and effective face-to-face human-machine interaction requires machines (e.g., robots) to understand and produce such human-like signals. There are many types of nonverbal signals used in this form of communication including, body postures, hand gestures, facial expressions, eye movements, touches and uses of space. This thesis investigates two of these nonverbal signals: hand gestures and eye-gaze. The main goal of the thesis is to propose computational methods for real-time recognition and generation of these two signals in order to facilitate natural and effective human-machine interaction.

    The first topic addressed in the thesis is the real-time recognition of hand gestures and its application to recognition of isolated sign language signs. Hand gestures can also provide important cues during human-robot interaction, for example, emblems are type of hand gestures with specific meaning used to substitute spoken words. The thesis has two main contributions with respect to the recognition of hand gestures: 1) a newly collected dataset of isolated Swedish Sign Language signs, and 2) a real-time hand gestures recognition method.

    The second topic addressed in the thesis is the general problem of real-time speech activity detection in noisy and dynamic environments and its application to socially-aware language acquisition. Speech activity can also provide important information during human-robot interaction, for example, the current active speaker's hand gestures and eye-gaze direction or head orientation can play an important role in understanding the state of the interaction. The thesis has one main contribution with respect to speech activity detection: a real-time vision-based speech activity detection method.

    The third topic addressed in the thesis is the real-time generation of eye-gaze direction or head orientation and its application to human-robot interaction. Eye-gaze direction or head orientation can provide important cues during human-robot interaction, for example, it can regulate who is allowed to speak when and coordinate the changes in the roles on the conversational floor (e.g., speaker, addressee, and bystander). The thesis has two main contributions with respect to the generation of eye-gaze direction or head orientation: 1) a newly collected dataset of face-to-face interactions, and 2) a real-time eye-gaze direction or head orientation generation method.

  • Disputas: 2018-06-08 10:15 F3, Stockholm
    Saglietti, Clio
    KTH, Skolan för teknikvetenskap (SCI), Mekanik, Stabilitet, Transition, Kontroll.
    On optimization of natural convection flows2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Two different techniques are presented for enhancing the thermal  performance of natural convection cooled heat sinks. The physics is  described by solving the conjugate heat transfer problem with a  spectral element method. The temperature distribution is computed in  two sub-domains, whose solution is then conjugated. Additionally, the  contribution of the natural convection to the heat transfer is  evaluated by solving the complete incompressible Navier–Stokes  equations in the fluid domain. One method focuses on the natural convection driven flow. The  disturbances about a base flow are sought, which yield the maximal  transient growth of a quadratic functional measuring the thermal  performance. The “optimal initial condition” method is used for  identifying the above mentioned perturbations. The control variable is  the initial state of the perturbation and the problem is subject to  the constraints enforced by the linearized governing equations. This  method is validated in a simple two--dimensional setup and then  applied to a periodic heat sink. The second approach is a topology optimization of the heat sink  itself. The design of the solid is optimized for maximizing the heat  flux. The control variable is a so-called material distribution  function that describes the presence of solid and fluid in the domain.  By modifying the design of the heat sink, the flow is optimally  conveyed and, by convection, it  extracts the maximal possible amount  of heat from the solid. The constraints are given by the governing  equations, the position of the heat sink, and some manufacturing  constraints (\textit{i.e.}, the maximal volume, or the minimal  thickness). After a validation in a two--dimensional setup, the method  is applied to a three--dimensional case. Complex tree-like shaped heat  sinks induce an increase of the thermal performance by 5 to 16\%,  depending on the conditions considered.

  • Disputas: 2018-06-07 09:00 Häggsalen, Uppsala
    Robo, Céline
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Bone-compliant cements for vertebral augmentation2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Acrylic bone cement based on poly(methyl methacrylate) (PMMA) is commonly used during vertebral augmentation procedures for the treatment of osteoporosis-induced vertebral compression fractures. However, the high stiffness of the cement compared to that of the surrounding trabecular bone is presumed to facilitate the formation of new fractures shortly after surgery. The aim of the thesis was to develop and evaluate a PMMA-based bone cement that better matches the mechanical properties of vertebral trabecular bone. To fulfill this objective, different compounds were added to the initial formulation of bone cement to modify its functional properties. Linoleic acid (LA) was found to give the best combination of strength and stiffness without negative effects on the handling properties and its use was therefore further investigated. In particular, different application-specific mechanical properties of LA-modified cement as well as itsin vivoperformance in an ovine model were assessed. 

    In summary, LA-modified cement exhibited bone-compliant mechanical properties immediately after incorporation of the additive, as well as adequate handling properties, in particular a lower polymerization temperature and appropriate setting time. The screw pullout strength from low-modulus cement was substantially reduced compared to regular PMMA cement, but comparable to some calcium phosphate based cements. The fatigue limit of LA-modified cement was considerably lower compared to regular PMMA bone cement when tested in physiological solution, but still higher than stresses measured in the spine during daily activities. The modified cement displayed similar inflammatory response in vivoto conventional cement, with no evidence of additional cytotoxicity due to the presence of LA. Finally, it was possible to sterilize the additive without significantly compromising its function in the PMMA cement.

    The results from this thesis support further evaluation of the material towards the intended clinical application. 

  • Öberg, Christian
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap. 8912104273.
    Zhu, Baohua
    Scania CV.
    Jonsson, Stefan
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Plastic deformation and creep of two ductile cast irons, SiMo51 and SiMo1000, during thermal cycling with large strainsInngår i: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cyclic deformations of two ferritic, ductile cast irons, SiMo51 and SiMo1000, were studied in air and Ar using a new method, SRTC (stress relaxation with thermal cycling). Locked specimens were thermally cycled up to 800 °C with isothermal holds, varying temperature interval, heating/cooling rates and hold times. A description of the mechanical response to thermal cycling of a locked specimen is given.

  • Disputas: 2018-06-07 13:15 Gunnelsalen Auditorium, Uppsala
    Otterman, Gabriel
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, Forskargrupper (Inst. för kvinnor och barns hälsa), Pediatrisk inflammationsforskning.
    Health sector and community response to child maltreatment in Sweden and in a European context2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Background Child maltreatment is a public health problem of global magnitude. This thesis examined different aspects of the multi-sector response to child maltreatment in Sweden and in Europe.

    Aims To explore how child physical abuse (CPA) is disclosed and how adolescents perceive adult support when they report physical abuse. To examine how police-reported cases of suspected CPA were associated with criminal investigation procedures and prosecutions. To assess how physicians who care for maltreated children across Europe are organised to recognise and respond to child abuse and neglect. To investigate time trends in rates of childhood deaths in Sweden recorded as due to external, ill-defined and unknown causes, from 2000 to 2014.

    Methods We analysed data from a school-based national survey of adolescents, police records of reported suspected CPA in a metropolitan area, a purposeful survey of European child abuse physicians and individual-level data from the Swedish cause of death register. We used quantitative methods to calculate prevalence, descriptive statistics, odds ratios, logistic regression and trends in mortality rates. Qualitative methods included content analysis and narrative synthesis.

    Results Only a minority of reported CPA was brought to the attention of professionals and the most prominent barrier to disclosure was lack of trust in adults or authorities. The police-reported cases of suspected CPA were characterised by high severity, but only a small proportion of the 158 alleged child victims were physically examined and only half were forensically interviewed. All 88 responding physicians in 22 European countries described multidisciplinary involvement in the management of suspected child maltreatment, but wide variations in the organisational approaches were revealed. A sustained decline in childhood deaths from external causes during a 15-year period was observed. A sizeable number of infant deaths were recorded each year as ill-defined or with incomplete documentation from clinicians.

    Conclusions The results presented in this thesis suggest that the multi-sector response in Sweden and in Europe is insufficiently organised, with no clear mandate for the health sector to robustly combat child maltreatment, and that this may undermine the ability of society to adequately protect children.

  • Carlson, Magnus
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematik (Avd.).
    Ahlqvist, Eric
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematik (Avd.).
    The cohomology ring of the ring of integers of a number fieldManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    We compute the étale cohomology ring H^*(Spec O_K,Z/nZ) where O_K is the ring of integers of a number field K. As an application, we give a non-vanishing formula for an invariant defined by Minhyong Kim.

  • Carlson, Magnus
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematik (Avd.).
    Schlank, Tomer
    Hebrew University of Jerusalem.
    The unramified inverse Galois problem and cohomology rings of totally imaginary number fieldsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    We employ methods from homotopy theory to define new obstructions to solutions of embedding problems. By using these novel obstructions we study embedding problems with non-solvable kernel. We apply these obstructions to study the unramified inverse Galois problem. That is, we show that our methods can be used to determine that certain groups cannot be realized as the Galois groups of unramified extensions of certain number fields. To demonstrate the power of our methods, we give an infinite family of totally imaginary quadratic number fields such that Aut(PSL(2,q^2)) for q an odd prime power, cannot be realized as an unramified Galois group over K, but its maximal solvable quotient can. To prove this result, we determine the ring structure of the \'etale cohomology ring H^*(Spec O_K;Z/2Z) where O_K is the ring of integers of an arbitrary totally imaginary number field K.

  • Carlson, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematik (Avd.).
    Tensor products of affine and formal abelian groupsManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    In this paper we study tensor products of affine abelian group schemes over a perfect field k. We first prove that the tensor product G_1 ⊗ G_2 of two affine abelian group schemes G_1,G_2  over a perfect field k exists. We then describe the multiplicative and unipotent part of the group scheme G_1 ⊗G_2. The multiplicative part is described in terms of Galois modules over the absolute Galois group of k. We describe the unipotent part of G_1 ⊗ G_2 explicitly, using Dieudonn\'e theory in positive characteristic. We relate these constructions to previously studied tensor products of formal group schemes.

  • Nikander, Hannele
    et al.
    Andersson, Agnes
    Sverdlilje, Vanja
    Jakobsen, Dorte
    Vihreiden jätteiden siirrot2018Annet (Annet (populærvitenskap, debatt, mm))
    Abstract [fi]

    Näihin ohjeisiin on koottu tietoja vihreiden jätteiden siirtoihin liittyvistä edellytyksistä. Pääsääntöisesti jätteen siirto maasta toiseen edellyttää lupaa. Poikkeuksena tästä ovat vaarattomien ns. vihreiden jätteiden siirrot hyödyntämistä varten. Oikeudellinen tausta on esitetty jätteensiirtoasetuksessa (EY) N:o 1013/2006. Asetuksen 3 ja 18 artiklat koskevat vihreiden jätteiden siirtoja.

  • Korpi, Tomas
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutet för social forskning (SOFI).
    Tåhlin, Michael
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Institutet för social forskning (SOFI).
    On-the-job training:A skill match approach to the determinants and outcomes of lifelong learning2018Rapport (Annet vitenskapelig)
  • Disputas: 2018-06-08 13:15 sal A1:111a, Uppsala
    Skinnars Josefsson, Malin
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Food Service and Nutritional Care in Swedish Elderly Care: The Progress of National Actions and their Local Interpretations2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The main aim of this thesis is to study local level outcomes regarding food service and nutritional care in Swedish elderly care in relation to the progress of national actions. Study I compared results from a repeated national survey using a questionnaire investigating the general structure and organisation of food service in elderly care. Study II built on data merged from a questionnaire, open comparison survey data and records from the quality registry Senior Alert to investigate nutritional care practice, focusing on quality indicators related to food service. Study III was a web-based questionnaire that described perceived facilitators in the process of adopting a national regulation that aims to prevent and treat malnutrition. Study IV explored associations between the level of adoption of the regulation and registrations in Senior Alert using registry data and results from a questionnaire.

           Differences were found primarily between rural and city municipality groups. The predominant food service organisation was public, but city municipalities reported a higher and increased use of private providers, chilled production and meal choices. The number of clinical/community dietitians had declined significantly between the surveys. Access to this profession was associated with being well-nourished. Food service dietitians and private providers were positively associated with meal satisfaction, while the food production system cook-chill was negatively associated. One year after the launch of the regulation, 50% of municipalities had adopted new routines. The odds for adoption were higher in municipalities where preventive work was already in progress, the regulation was considered helpful, and where facilitators had long experience of working in elderly care. The most important support factors for the adoption of new routines were cooperation between professions and well-defined goals. There was no significant difference in nutritional screening scores associated with adoption rate, but, in general, the number of individuals registered in Senior Alert increased after the entry into force of the regulation.

         In conclusion, this thesis contributes increased knowledge about the different outcomes in local level practices in relation to central actions. The results indicate a strong local autonomy and the importance of local access to sufficient capacity and knowledge.

  • Sigmundsson, Thorir Svavar
    et al.
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Öhman, Tomas
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Hallbäck, Magnus
    Maquet Crit Care AB, Solna, Sweden..
    Redondo, Eider
    Hosp Navarra, Dept Intens Care Med, Pamplona, Spain..
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain..
    Wallin, Mats
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Maquet Crit Care AB, Solna, Sweden..
    Oldner, Anders
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Sander, Caroline Hällsjö
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Björne, Håkan
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Performance of a capnodynamic method estimating effective pulmonary blood flow during transient and sustained hypercapnia2018Inngår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 32, nr 2, s. 311-319Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The capnodynamic method is a minimally invasive method continuously calculating effective pulmonary blood flow (COEPBF), equivalent to cardiac output when intra pulmonary shunt flow is low. The capnodynamic equation joined with a ventilator pattern containing cyclic reoccurring expiratory holds, provides breath to breath hemodynamic monitoring in the anesthetized patient. Its performance however, might be affected by changes in the mixed venous content of carbon dioxide (CvCO2). The aim of the current study was to evaluate COEPBF during rapid measurable changes in mixed venous carbon dioxide partial pressure (PvCO2) following ischemia-reperfusion and during sustained hypercapnia in a porcine model. Sixteen pigs were submitted to either ischemia-reperfusion (n = 8) after the release of an aortic balloon inflated during 30 min or to prolonged hypercapnia (n = 8) induced by adding an instrumental dead space. Reference cardiac output (CO) was measured by an ultrasonic flow probe placed around the pulmonary artery trunk (COTS). Hemodynamic measurements were obtained at baseline, end of ischemia and during the first 5 min of reperfusion as well as during prolonged hypercapnia at high and low CO states. Ischemia-reperfusion resulted in large changes in PvCO2, hemodynamics and lactate. Bias (limits of agreement) was 0.7 (-0.4 to 1.8) L/min with a mean error of 28% at baseline. COEPBF was impaired during reperfusion but agreement was restored within 5 min. During prolonged hypercapnia, agreement remained good during changes in CO. The mean polar angle was -4.19A degrees (-8.8A degrees to 0.42A degrees). Capnodynamic COEPBF is affected but recovers rapidly after transient large changes in PvCO2 and preserves good agreement and trending ability during states of prolonged hypercapnia at different levels of CO.

  • Ternström, Sten
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH, Musikakustik.
    Nordmark, Jan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Tal, musik och hörsel, TMH, Musikakustik.
    Intonation preferences for major thirds with non-beating ensemble sounds1996Inngår i: Proc. of Nordic Acoustical Meeting: NAM'96, Helsinki, 1996, s. 359-365, artikkel-id F2Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The frequency ratios, or intervals, of the twelve-tone scale can be mathematically dejned in several slightly diferent ways, each of which may be more or less appropriate in different musical contexts. For maximum mobility in musical key, instruments of our time with fixed tuning are typically tuned in equal temperament, except for performances of early music or avant-garde contemporary music. Some contend that pure intonation, being free of beats, is more natural, and would be preferred in instruments with variable tuning. The sound of choirs is such that beats are very unlikely to serve as cues for intonation. Choral performers have access to variable tuning, yet have not been shown to prefer pure intonation. The difference between alternative intonation schemes is largest for the major third interval. Choral directors and other musically expert subjects were asked to adjust to their preference the intonation of 20 major third intervals in synthetic ensemble sounds. The preferred size of the major third was 395.4 cents, with intra-subject averages ranging from 388 to 407 cents.

  • Jakobsson, Peter
    et al.
    Södertörns högskola, Institutionen för kultur och lärande, Medie- och kommunikationsvetenskap.
    Stiernstedt, Fredrik
    Södertörns högskola, Institutionen för kultur och lärande, Medie- och kommunikationsvetenskap.
    Arbetarklassens symboliska utplåning i medelklassens medier2018Rapport (Annet vitenskapelig)
    Abstract [sv]

    I denna rapport redovisas resultat från den existerande forskningen – både i Sverige och internationellt – kring relationerna mellan samhällsklass och medier. Bland annat ser vi att arbetarklassen är kraftigt underrepresenterad och osynliggjord – den undanhålls både röst och erkännande – i svenska medier och att avsaknaden av representation i medierna kan leda till en (berättigad) känsla av osynliggörande som i sin tur kan ligga till grund för ett avståndstagande från medierna. Vidare ser vi att klasserna är betydligt mer ”segregerade” i televisionens genresystem i dag än vad som var fallet för 35 år sedan; arbetarklassen har i det närmaste försvunnit från nyheter och faktaprogram och återfinns istället huvudsakligen i film, drama och reality-program. Just reality-tv ger dramatisk form till dominerande ideologier som på samma gång exploaterar klass – för att skapa narrativ dramatik – och förnekar eller undertrycker frågan om klass och klasskonflikter. Inte minst gestaltas personer från arbetarklassen på ett stereotypt, nedsättande och hånfullt sätt. Avsaknad av röst och erkännande kan blockera formeringen av klassidentitet och minska arbetarrörelsens möjligheter att organisera sig och formera sig för politisk kamp. Vad gör dagens svenska arbetarrörelse på detta område?

  • van Dijkman, Sven C.
    et al.
    Leiden Acad Ctr Drug Res, Div Pharmacol, Leiden, Netherlands..
    Wicha, Sebastian G.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Danhof, Meindert
    Leiden Acad Ctr Drug Res, Div Pharmacol, Leiden, Netherlands..
    Della Pasqua, Oscar E.
    GlaxoSmithKline, Clin Pharmacol Modelling & Simulat, Uxbridge, Middx, England.;UCL, Clin Pharmacol & Therapeut, London, England..
    Individualized Dosing Algorithms and Therapeutic Monitoring for Antiepileptic Drugs2018Inngår i: Clinical Pharmacology and Therapeutics, ISSN 0009-9236, E-ISSN 1532-6535, Vol. 103, nr 4, s. 663-673Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pharmacokinetic (PK) models exist for most antiepileptic drugs (AEDs). Yet their use in clinical practice to assess interindividual differences and derive individualized doses has been limited. Here we show how model-based dosing algorithms can be used to ensure attainment of target exposure and improve treatment response in patients. Using simulations, different treatment scenarios were explored for 11 commonly used AEDs. For each drug, five scenarios were considered: 1) all patients receive the same dose. 2) Individual clearance (CL), as predicted by population PK models, is used to personalize treatment. 3-5) Individual CL, obtained by therapeutic drug monitoring (TDM) according to different sampling schemes, is used to personalize treatment. Attainment of steady-state target exposure was used as the performance criterion to rank each scenario. In contrast to current clinical guidelines, our results show that patient demographic and clinical characteristics should be used in conjunction with TDM to personalize the treatment of seizures.

  • Disputas: 2018-06-08 10:00 Vivi Täckholmssalen (Q-salen), Stockholm
    Deyanova, Diana
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Seagrass productivity: from plant to system2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Seagrasses form one of the most productive habitats on earth and are recognized as very efficient carbon sinks. The levels and patterns of productivity within and across different seagrass systems vary widely due to natural or human-induced factors. Seagrass plants, being the foundation species of seagrass meadows, have a substitutional role as primary producers to the overall productivity of their habitat. Clarifying the variation in the carbon capture potential of these plants on physiological and ecological levels is essential to understand of the whole system’s carbon balance. In this thesis, the photosynthetic performance and productivity of seagrass plants were studied in relation to factors that have large impact on productivity, such as tissues age, season and water depth. Furthermore, the seagrass response, in terms of capacity to capture and sequester carbon, to human-induced stress factors such as shading and simulated grazing was evaluated in a tropical seagrass meadow. The research has included a multitude of seagrass productivity assessments from plant- to system level.

    The results showed that age has a significant effect on the photosynthetic performance of the temperate seagrass Zostera marina L., both within a single shoot and between shoots. When comparing leaves among the same shoot, the photosynthetic capacity and efficiency were highest in mature tissues and significantly reduced in very young tissues as well as in tissues undergoing senescence. In response to high light stress, very young tissues seemed to cope better with dissipating excess light energy, which was demonstrated by the higher values of non-photochemical quenching (NPQ) observed compared to mature and senescent tissues. Such an effect was also observed when comparing the oldest and youngest shoots from the same genet; the youngest shoot showed higher ability to dissipate excess light energy compared to the oldest one, and might thus be able to better withstand light stress.

    On a larger spatiotemporal scale, the areal productivity of seagrass plants was significantly affected by light availability and temperature, leading to a strong seasonal variation. In addition, depth had a strong site-specific effect on plant productivity in terms of biomass. On a yearly basis, productivity rates varied substantially, reaching up to 20 g C m-2 24h-1 in the summer months. This high carbon capture potential was, however, outbalanced by the high respiration rates of the benthic community. Overall, the whole system had a low but positive yearly carbon balance.

    Both shading and simulated grazing negatively affected seagrass plants and the whole habitat after five months of experimental disturbance. On the plant level, photosynthesis, productivity and growth were all reduced. On the system level, a reduction in community productivity was recorded. The long-term refractory carbon was, however, not affected although erosion was observed in treatments subjected to simulated grazing.

    In summary, this thesis has established that age, season, depth and exposure are factors highly responsible for natural variation in seagrass plant- and habitat productivity, and that seagrasses respond to human-induced stress by significantly reducing their productivity. Even though seagrass plants are generally capable of surviving stress periods, these results suggest that prolonged deteriorating stress conditions will lead to serious harm on the plants as well as the entire habitat, and thereby compromising the carbon burial capacity of the seagrass system.

  • Disputas: 2018-06-08 09:00 David Magnussonsalen (U31), Stockholm
    Ekström, Ingrid
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen.
    Human olfaction: Associations with longitudinal assessment of episodic memory, dementia, and mortality risk2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    A declining sense of smell is a common feature in older age. Above and beyond diminished smelling capacity due to normal processes of human aging, impairments in olfactory function have also been linked to numerous ill-health related outcomes, such as cognitive dysfunctions, dementia pathology and even an increased risk of death. Based on population-based data from the Swedish Betula Prospective Cohort Study, the aim of this thesis was to further our understanding regarding the role of olfaction in long-term memory decline, dementia, and mortality. Furthermore, this thesis investigated the predictive utility of self-reported olfactory dysfunction for assessing the risk of conversion to later dementia and to mortality, as well as the predictive utility of long-term subjective olfactory decline for an actual long-term decline in odor function. Study I explored associations of olfactory deficits with memory decline and found that impairments in an odor identification test were related to an ongoing and long-term decline in episodic memory only in carriers of the e4 allele of the Apolipoprotein E, a genetic risk factor for Alzheimer’s disease. Study II investigated the predictive utility of olfactory ability for conversion to common forms of dementia in participants with intact baseline cognition during a follow-up time-span of 10 years. The results showed that lower odor identification scores, as well as subjectively assessed odor impairment, were associated with an increased risk for dementia conversion, and that the effects of objective and subjective odor function were cumulative. Study III investigated whether olfactory ability could predict mortality and showed that lower odor identification scores, as well as subjective odor impairments, were associated with an elevated risk of death within a follow-up time-span of approximately 10 years. Crucially, this effect could not be explained by dementia conversion prior to death. Study IV showed that a subjectively assessed long-term and ongoing olfactory decline was predictive of an objectively assessed long-term and ongoing decline in odor function. Subjective olfactory impairments might thus be indicative of an actual olfactory decline in older adults. Overall, the findings of this thesis indicate that sense of smell is closely related to processes of memory decline and dementia as well as mortality in older adults. Furthermore, the results of these investigations shed a new light on the role of subjectively experienced olfactory decline, which might reflect an actual intra-individual change in olfactory ability in older adults.

  • Disputas: 2018-06-08 09:30 Magnéli Hall, Arrhenius Laboratory, Stockholm
    Zhu, Chuantao
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK).
    Nanocellulose and Its Biohybrids for Water Purification: Atomic Force Microscopy as a Tool to Probe Surface Properties and Interactions2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Nanocellulose has been explored extensively in recent years as an adsorbent due to its promising performance in the removal of charged contaminants from water. In this thesis, various atomic force microscopy (AFM) techniques are used to understand the surface characteristics and specific interactions of nanocellulose with water contaminants (heavy metal ions and dyes) and nanoscale entities (Graphene Oxide (GO) and Graphene Oxide nanocolloids (nanoGO)), and explain the mechanisms related to adsorption, metal ion clustering, self-assembly and mechanical reinforcement.

    AFM probes functionalised with microscale and nanoscale celluloses were used as colloidal probes to study specific surface interactions with heavy metal ions and dyes in the aqueous medium. This approach enabled quantitative measurements of the adhesion force between nanocellulose and the water pollutants under in situ conditions by direct or in-direct methods. Adhesion forces, including the piconewton range, were measured, and the forces depended on the surface groups present on the nanocellulose.

    AFM imaging in dry and/or wet conditions was successfully used to investigate the adsorption, self-assembly, morphology and mechanical properties of nanocellulose and its bio-hybrids. The self-assembly, the metal nanolayer and the nanoclusters on the surface of nanocellulose and its biohybrids after adsorption were confirmed and explained by advanced microscopy, spectroscopy and computational modelling.

    The adhesion and stiffness measurement of single nanocellulose fibers using in situ PeakForce Quantitative Nanomechanical (PF-QNM) characterization confirmed the adsorption of metal ions on the surface in the liquid medium. PF-QNM mapping of the freestanding biohybrid membranes also revealed the enhanced modulus of the biohybrid membrane compared with the TEMPO(2,2,6,6-tetramethylpiperidine-1-oxylradical)-mediated oxidation nanofibers (TOCNF) membrane, which explained the hydrolytic stability and recyclability of these membranes.

    The established methodology, which combines advanced microscopy with spectroscopy and modelling techniques, can be extended to other biobased macromolecular systems to investigate the adsorption behaviour and/or surface interactions in bio nanotechnology.

  • Disputas: 2018-06-08 13:00 sal 14, hus 5, Kräftriket, Stockholm
    Marseglia, Stefano
    Stockholms universitet, Naturvetenskapliga fakulteten, Matematiska institutionen.
    Computing abelian varieties over finite fields2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In this thesis we address the problem of developing effective algorithms to compute isomorphism classes of polarized abelian varieties over a finite field and of fractional ideals of an order in a finite product of number fields.

    There are well-known methods to efficiently compute the classes of invertible ideals of an order in a number field, but not much has previously been known about non-invertible ideals. In Paper I we produce algorithms to compute representatives of all ideal classes of an order in a finite product of number fields. We also extend a theorem of Latimer and MacDuffee about  conjugacy classes of integral matrices.

    There are equivalences established by Deligne and Centeleghe-Stix between the category of abelian varieties over a finite field and the category of finitely generated free abelian groups with an endomorphism satisfying some easy-to-state axioms, which in certain cases can be described in terms of fractional ideals of orders in finite products of number fields. In Paper II we use this method to produce an algorithm that computes the isomorphism classes of abelian varieties in an isogeny class determined by an ordinary square-free q-Weil polynomial or by a square-free p-Weil polynomial with no real roots (where p denotes a prime and q is a power of a prime). In the ordinary case we also produce an algorithm that computes the polarizations up to isomorphism and the automorphism groups of the polarized abelian varieties. If the polarization is principal, we can compute a period matrix of the canonical lift of the abelian variety.

    In Paper III we extend the description of the second paper to the case when the Weil polynomial is a power of a square-free polynomial which fulfills the same requirements as in Paper II.

    In Paper IV we use the results of the second and third papers to study questions related to base-field extension of the abelian varieties over finite fields.

  • Disputas: 2018-06-08 13:00 JMK-salen, Garnisonen, Stockholm
    Thor, Tindra
    Stockholms universitet, Humanistiska fakulteten, Institutionen för mediestudier.
    Painting the City: Performative Cosmopolitanism and the Politics of Space and Art2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Understanding everyday urban practices as performative, political, and potentially transformative, this dissertation aims to explore how graffiti- and street art use, subvert, and, via media, extend urban space in Stockholm. Drawing upon a performative ethnographic approach, the study focuses on both the practice of and the various forms of social commentary and critique generated by graffiti and street art in Stockholm. The findings illustrate the diversity of positionalities that abide in this cultural cluster, noting, in particular, the ambiguities, juxtaposition and tensions therein. Furthermore, the dissertation explores the cosmopolitan potentials of graffiti and street art as transnational movements, which create connections through shared imaginaries and senses of belonging. The analysis is based upon in-depth interviews, nine months of fieldwork, and numerous photographs, and addresses three research questions: (1) how is contemporary Stockholm graffiti- and street art culture articulated and performed by its makers and in what ways the culture collapse with other media than “writing”/painting?, (2) what characterizes the scope of social critique articulated as part of the performative repertoires of Stockholm graffiti and street art discourses? and, (3) what are the critical and aesthetic cosmopolitan potentials and/or deficits of graffiti- and street art culture and under which conditions do they materialize?

    Theoretically, the study draws on the concept of aesthetic cosmopolitanism in order to explore and analyze the acts and practices of “world-making” through aesthetic performances. By linking aesthetic cosmopolitanism with ancient Cynic philosophy, the concept of performative cosmopolitanism is introduced. Performative cosmopolitanism captures the varieties of outlooks and spaces that open up through critical, sensorial, and, in certain cases, even transformative, interventions in the city and their mediated extensions. Using mediatization as a paradigmatic approach, both an increase in digital dissemination and visibility and a decrease in actual performances and visibility are observed. In this respect, the mediatization of graffiti and street art remains a paradoxical process. Given the entanglement of different media with graffiti and street art performances, the study further introduces the concept of hyper-mediatization to articulate an interdependent relationship between the actual and virtual forms of these urban performances: they fundamentally affect and extend each other by both sustaining and expanding existing imaginaries and connections and generating emergent ones. 

    The dissertation paints the image of a contested, controversial and subversive urban culture and its contemporary mediatized extensions. It shows how graffiti and street art can be understood, both culturally and politically, as a critical, alternative and essentially anti-capitalist aesthetization of the urban. Utilizing the concept of regimes of cosmopolitanism, the author highlights the potentials and deficits of “comingtogetherness” through and during creative practice and the dual dynamics of hospitality and encapsulation. Particular emphasis is placed upon the tensions related to gender and the ways in which such tensions factor into the social relations within these artistic communities and the aesthetics they produce. 

  • Disputas: 2018-06-09 10:00 Auditorium 215, Humanistvillan, Stockholm
    Ohlsson, Hélène
    Stockholms universitet, Humanistiska fakulteten, Institutionen för kultur och estetik.
    ”Gudomlig, ingenting mindre än gudomlig!”: Skådespelerskan Ellen Hartmans iscensättningar på scen och i offentlighet2018Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The purpose of the thesis is to examine the diva femininity, career strategies, and acting style of the Swedish actress Ellen Hartman (1860-1945). The aim is to highlight her importance to Swedish theater during the fin-de-siècle. The dissertation is a contribution to the history of actresses and explores her gender performance and diva codes and how they influenced her career strategies and acting style. The analysis is based on Tracy C. Davis’s feminist historiography, Mimi Schippers’s notion of pariah femininity, and Wayne Koestenbaum's concept of diva codes.

    Historical contextualisation, critical imaginativeness, and actors’ embodied knowledge are the methodologies used in the present thesis. The study emphasizes the close interplay of the gendered contexts and structures that framed Hartman’s career strategies, acting style and performance. The conclusion thereby underlines the idea that Hartman as a popular actress challenged the gender norms of her time and contributed to the empowerment of women in Sweden. As an actress, Hartman was a forerunner and thereby became a pioneer of Swedish modern acting.

  • Chraibi, S.
    et al.
    Philips Lighting B.V., Eindhoven, the Netherlands.
    Creemers, P.
    Department of the Built Environment, Building Lighting Group, Eindhoven University of Technology, Eindhoven, the Netherlands.
    Rosenkötter, C.
    Department of the Built Environment, Building Lighting Group, Eindhoven University of Technology, Eindhoven, the Netherlands.
    van Loenen, E. J.
    Department of the Built Environment, Building Lighting Group, Eindhoven University of Technology, Eindhoven, the Netherlands.
    Aries, Myriam
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Byggnadsteknik och belysningsvetenskap. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Bebyggd miljö.
    Rosemann, A. L. P.
    Department of the Built Environment, Building Lighting Group, Eindhoven University of Technology, Eindhoven, the Netherlands.
    Dimming strategies for open office lighting: User experience and acceptance2018Inngår i: Lighting Research and Technology, ISSN 1477-1535, E-ISSN 1477-0938Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sensor-triggered control strategies can limit the energy consumption of lighting by considering the presence of users in the office and dimming lighting down when it is not needed. In multi-user offices, the application of occupancy-based dimming at room level limits the energy saving potential. However, zone- or desk-based dimming may affect the comfort of co-workers due to its dynamics. This paper reports the assessment by 17 participants (30–50 years of age) of occupancy-based dimming in a mock-up office, using different dimming speeds. Participants consisted of co-workers experiencing changes triggered by others, and actors triggering these light changes. While the participants performed an office-based task, the luminaire above the actors’ desk was dimmed from approximately 550 lx to 350 lx (average horizontal illuminance), and vice versa. The participants evaluated the dimming conditions regarding their noticeability and acceptability. The study showed that the noticeability of light changes due to dimming, increases when fading times become shorter. Dimming with a fading time of at least two seconds was experienced as acceptable by more than 70% of the participants. The results of this experiment provide insights to system behaviour that does not compromise user experience while addressing energy efficient use of electric lighting.

  • Disputas: 2018-06-08 10:00 Air and Fire, Science for Life Laboratory, Solna
    Alneberg, Johannes
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Genteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Bioinformatic Methods in Metagenomics2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Microbial organisms are a vital part of our global ecosystem. Yet, our knowledge of them is still lacking. Direct sequencing of microbial communities, i.e. metagenomics, have enabled detailed studies of these microscopic organisms by inspection of their DNA sequences without the need to culture them. Furthermore, the development of modern high- throughput sequencing technologies have made this approach more powerful and cost-effective. Taken together, this has shifted the field of microbiology from previously being centered around microscopy and culturing studies, to largely consist of computational analyses of DNA sequences. One such computational analysis which is the main focus of this thesis, aims at reconstruction of the complete DNA sequence of an organism, i.e. its genome, directly from short metagenomic sequences.

    This thesis consists of an introduction to the subject followed by five papers. Paper I describes a large metagenomic data resource spanning the Baltic Sea microbial communities. This dataset is complemented with a web-interface allowing researchers to easily extract and visualize detailed information. Paper II introduces a bioinformatic method which is able to reconstruct genomes from metagenomic data. This method, which is termed CONCOCT, is applied on Baltic Sea metagenomics data in Paper III and Paper V. This enabled the reconstruction of a large number of genomes. Analysis of these genomes in Paper III led to the proposal of, and evidence for, a global brackish microbiome. Paper IV presents a comparison between genomes reconstructed from metagenomes with single-cell sequenced genomes. This further validated the technique presented in Paper II as it was found to produce larger and more complete genomes than single-cell sequencing.

  • Wennberg, Maria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Näringsforskning.
    Ruuth, Anders
    Department of Obstetrics and Gynaecology, Sunderby Hospital, Luleå, Sweden.
    Andersson, Liselott
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Obstetrik och gynekologi. Department of Obstetrics and Gynaecology, Sunderby Hospital, Luleå, Sweden.
    Bergdahl, Ingvar A.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin. Umeå universitet, Medicinska fakulteten, Enheten för biobanksforskning.
    Mercury concentrations in pregnant women in circumpolar Sweden (Kiruna)2018Rapport (Annet vitenskapelig)
    Abstract [en]

    High exposure to mercury have been found in populations living in circumpolar areas, due to high consumption of sea food and accumulation of mercury closer to the north pole. The developing fetus is especially sensitive to effects of mercury. Exposure to mercury has previously been examined in pregnant women in Sweden, but not in pregnant women residing in Sweden north of the polar circle.

    In the years 2015-2016, mercury was measured in whole blood from 51 pregnant women living in the city of Kiruna in circumpolar Sweden, taking part in an international comparison between eight circumpolar countries. This report presents the Swedish results on mercury concentrations and associations with some exposure determinants. Also, compliance to dietary advice on fish consumption, appointed to fertile women, was examined.

    The median concentration of total-Hg in whole blood was 0.40 μg/L (min, max; <0.40, 1.88) among the 51 pregnant women in Kiruna. This is similar or lower compared to concentrations of mercury in pregnant women in other parts of Sweden. None of the women in the study had concentrations of mercury that are considered as dangerous.

    Mercury concentrations were associated with total fish consumption but not to consumption of predatory fish, known to be higher in mercury. All of the women in the study had knowledge about dietary advice on fish consumption. One woman exceeded the recommended consumption of predatory fish, limited due to risk of high mercury content, but this woman did not have high concentrations of mercury. While the vast majority of women thus followed the recommendations of not eating too much polluted fish, only 15 % of the women reported sufficient fish consumption to comply with the dietary advice (2-3 times/week).

    In conclusion, pregnant women in circumpolar Sweden have low exposure to mercury, and do not deviant from pregnant women in other parts of Sweden. Knowledge about dietary advice on fish consumption appointed to fertile women is very good. The public health concern though, is that pregnant women in circumpolar Sweden do not eat enough fish.

  • Dosio, Alessandro
    et al.
    Mentaschi, Lorenzo
    Fischer, Erich M.
    Wyser, Klaus
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Extreme heat waves under 1.5 degrees C and 2 degrees C global warming2018Inngår i: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 13, nr 5, artikkel-id 054006Artikkel i tidsskrift (Fagfellevurdert)
  • Disputas: 2018-06-15 13:00 L111, Sundsvall
    Dima, Elijs
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Multi-Camera Light Field Capture: Synchronization, Calibration, Depth Uncertainty, and System Design2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The digital camera is the technological counterpart to the human eye, enabling the observation and recording of events in the natural world. Since modern life increasingly depends on digital systems, cameras and especially multiple-camera systems are being widely used in applications that affect our society, ranging from multimedia production and surveillance to self-driving robot localization. The rising interest in multi-camera systems is mirrored by the rising activity in Light Field research, where multi-camera systems are used to capture Light Fields - the angular and spatial information about light rays within a 3D space. 

    The purpose of this work is to gain a more comprehensive understanding of how cameras collaborate and produce consistent data as a multi-camera system, and to build a multi-camera Light Field evaluation system. This work addresses three problems related to the process of multi-camera capture: first, whether multi-camera calibration methods can reliably estimate the true camera parameters; second, what are the consequences of synchronization errors in a multi-camera system; and third, how to ensure data consistency in a multi-camera system that records data with synchronization errors. Furthermore, this work addresses the problem of designing a flexible multi-camera system that can serve as a Light Field capture testbed.

    The first problem is solved by conducting a comparative assessment of widely available multi-camera calibration methods. A special dataset is recorded, giving known constraints on camera ground-truth parameters to use as reference for calibration estimates. The second problem is addressed by introducing a depth uncertainty model that links the pinhole camera model and synchronization error to the geometric error in the 3D projections of recorded data. The third problem is solved for the color-and-depth multi-camera scenario, by using a proposed estimation of the depth camera synchronization error and correction of the recorded depth maps via tensor-based interpolation. The problem of designing a Light Field capture testbed is addressed empirically, by constructing and presenting a multi-camera system based on off-the-shelf hardware and a modular software framework.

    The calibration assessment reveals that target-based and certain target-less calibration methods are relatively similar at estimating the true camera parameters. The results imply that for general-purpose multi-camera systems, target-less calibration is an acceptable choice. For high-accuracy scenarios, even commonly used target-based calibration approaches are insufficiently accurate. The proposed depth uncertainty model is used to show that converged multi-camera arrays are less sensitive to synchronization errors. The mean depth uncertainty of a camera system correlates to the rendered result in depth-based reprojection, as long as the camera calibration matrices are accurate. The proposed depthmap synchronization method is used to produce a consistent, synchronized color-and-depth dataset for unsynchronized recordings without altering the depthmap properties. Therefore, the method serves as a compatibility layer between unsynchronized multi-camera systems and applications that require synchronized color-and-depth data. Finally, the presented multi-camera system demonstrates a flexible, de-centralized framework where data processing is possible in the camera, in the cloud, and on the data consumer's side. The multi-camera system is able to act as a Light Field capture testbed and as a component in Light Field communication systems, because of the general-purpose computing and network connectivity support for each sensor, small sensor size, flexible mounts, hardware and software synchronization, and a segmented software framework. 

  • Falk Delgado, Alberto
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Plastikkirurgi.
    Falk Delgado, Anna
    Karolinska Inst, Dept Clin Neurosci, Stockholm, Sweden..
    Home institution bias in the New England Journal of Medicine?: A noninferiority study on citation rates2018Inngår i: Scientometrics, ISSN 0138-9130, E-ISSN 1588-2861, Vol. 115, nr 1, s. 607-611Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recently, in the four top journals of humanities, an institutional bias towards publication of authors from Harvard and Yale was shown. The New England Journal of Medicine (NEJM) is today the highest ranked general medical journal. It is unknown if there exists institutional bias favoring publication of articles originating from Harvard University, since the NEJM is produced by the Massachusetts Medical Society with close connections to the Harvard University. We examined if studies originating from the Harvard University published in the NEJM were noninferior in terms of citation rates compared to articles with an origin outside Harvard University. We evaluated original research articles published in the NEJM in 2000 up until June 2001. A two-sample noninferiority test based on the primary endpoint of citations was performed. Twenty-two studies were affiliated to the Harvard University and 280 studies were not affiliated to the Harvard University. The mean number of citations for Harvard affiliated studies was 625 (95% CI 358-952, median 354) and for non-Harvard affiliated studies 493 (95% CI 421-569, median 303). The mean difference was not statistically different between affiliations, but fulfilled the requirements for noninferiority [132 (95% CI - 138-402, P = 0.343), Delta 200]. In summary, citation rates were comparable between studies origination from the Harvard University compared to non-Harvard Institutions. Based on these results there appears to be low risk of institutional bias in the publishing process of original studies in the NEJM.

  • Wu, Lichuan
    et al.
    Hristov, Tihomir
    Rutgersson, Anna
    Vertical Profiles of Wave-Coherent Momentum Flux and Velocity Variances in the Marine Atmospheric Boundary Layer2018Inngår i: Journal of Physical Oceanography, ISSN 0022-3670, E-ISSN 1520-0485, Vol. 48, nr 3, s. 625-641Artikkel i tidsskrift (Fagfellevurdert)
  • Disputas: 2018-06-11 10:00 FA32, Stockholm
    Ignatova, Nina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi. Siberian Federal University.
    Multimode resonant X-ray scattering of free molecules2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis is focused on the role that nuclear dynamics plays in the formation of X-ray absorption (XAS) and resonant inelastic X-ray scattering (RIXS) spectra of multimode free molecules. A combined approach based on ab initio electronic structure methods and quantum nuclear wave packet dynamics is applied to two systems -- water and methanol in the gas phase. An IR-pump – X-ray-probe spectroscopy of vibrationally excited water and its isotope substitutions is employed to explore different vibrational progressions of the final electronic state due to a spatial filtration of the vibrations in the core-excited state and selection rules. It was demonstrated the possibility to use RIXS as a tool to study X-ray absorption from a selected vibrational level of the ground state. IR-pump – X-ray-probe spectroscopy applied to the HDO molecule sheds light on the old classical problem of wave function collapse: we demonstrate numerically the gradual collapse of the initially localised vibrational wave function in the HDO molecule. It is also explained the dynamical nature of the splitting of the 1b1 peak in the RIXS spectrum of H2O, HDO and D2O molecules. This splitting is referred to close-lying molecular and atomic-like peaks. In order to study the methanol molecule a special theoretical tool for studies of multimode molecules has been developed. This approach combines the advantages of the quantum wave packet technique for simulations of the dynamics in dissociative states with the efficiency of the Franck-Condon method for computing transitions between bound states. It is shown that the multimode nuclear dynamics plays an important role in XAS and RIXS spectra of methanol. The XAS and RIXS spectra formation was explained taking into account different dynamics in different core-excited potential energy surfaces, as well as the entanglement of vibrational modes by anharmonicity and by the life-time vibrational interference.

  • Disputas: 2018-06-08 10:00 William Olsson-salen, Geovetenskapens hus, Stockholm
    Blomqvist, Per
    Stockholms universitet, Humanistiska fakulteten, Institutionen för språkdidaktik.
    Samtal om skrivbedömning: Lärares normer, beslut och samstämmighet2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis reports and discusses results from a qualitative study of Swedish teachers' writing assessment in upper secondary school. Based on teacher group discussions, the study investigates teachers' interactions, expressions of norms and decisions when assessing and grading students' writing in the subject of Swedish.

    The aim of the study is to describe and analyze how teachers interact and what they pay attention to when discussing writing assessment. In relation to this aim the following three research questions were posed: (1) What characterizes the teachers' conversations about writing assessment? (2) What assessment norms do the teachers express? (3) What decisions do they make?

    The theoretical perspectives are dialogical and pedagogical. From a dialogical point of view, the assessment conversations are considered as social acts where teachers in interaction collectively create meaning. Furthermore, the assessment conversations are considered as pedagogical, as a part of teachers' reflective work to discuss how to assess students' work and how to make decisions about further instructions and grading. The methods used to describe and analyze interactional patterns, expressions of norms and decisions in these assessment conversations are topic analysis and initiative-response-analysis.

    The empirical data consists of audio and video recordings from three teacher groups' conversations about writing assessment, comprising a total of 17 Swedish teachers from three upper secondary schools. Data was also collected via a questionnaire with the individual teacher's grading of the students' writing and evaluation of the assessment conversations.

    The results show that teachers' assessments of students' writing focus on much more, and partly other, criteria than their pedagogical decisions. The quality standards that teachers express in the discussions about student texts focus mostly on communicative quality, language style and text structure but also on content and the use of sources. The pedagogical decisions, on the other hand, almost exclusively focus on text structure and the use of sources.

    The results also show that shortcomings in the students' texts are crucial for teachers' summative assessments. Meanwhile, the teachers also express that students' age, their writing development in the course and the national test must be considered. These assessment norms can be compensatory and have a substantial impact on these teachers' decisions on summative assessments. The teacher groups show considerable variation in the basis for their decisions regarding summative assessment of students' writing.

    Finally, the teachers demonstrate a high degree of consistency within each teacher group when discussing summative assessment of students' writing. However, the assessments that individual teachers make after the discussions comply only to some extent with the group's decisions. The least degree of consistency was shown by the teacher group who, in the discussion, seemed the most consistent. Decision-making processes in these discussions are characterized by low intensity, where few assessment alternatives are being considered. The overall assessment consistency between the teacher groups was found to be low.

  • Moshi, Haleluya
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi. Kilimanjaro Cristian Medical University College, Moshi, Tanzania.
    Sundelin, Gunnevi
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Sahlén, Klas-Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Epidemiologi och global hälsa. Umeå universitet, Medicinska fakulteten, Institutionen för omvårdnad.
    Anthea, Rhoda
    Sörlin, Ann
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Fysioterapi.
    Coping Resources for Persons With Traumatic Spinal Cord Injury in A Tanzania Rural Area2018Inngår i: Global Journal of Health Science, ISSN 1916-9736, E-ISSN 1916-9744, Vol. 10, nr 5, s. 138-153Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Persons with traumatic spinal cord injury (TSCI) in Tanzanian rural settings face a variety of geographical and socioeconomic challenges that make life almost impossible for them. However, some have managed to live relatively long lives despite these difficult conditions. This study aimed at exploring secrets behind successful lives of persons with TSCI in typical resource-constrained rural Tanzanian settings.

    METHODS: A modified constructivist grounded theory was employed for the analysis of data from 10 individuals who have lived between 7 and 28 years with TSCI in typical Tanzanian rural area. The 10 were purposively selected from 15 interviews that were conducted in 2011. The analysis followed the constructivist approach in which data was first open and axial coded, prior to categories being constructed. The categories were frequently reviewed in light of the available literature to determine the over-arching core category that described or connected the rest.

    RESULTS: Nine categories (identified as internal and external coping resources) were constructed. The internal coping resources were: secured in God, increase in awareness on health risk, problem-solving skills and social skills. External coping resources were: having a reliable family, varying support from the community, a matter of possession and left without means for mobility. Acceptance was later identified as a core category that determines identification and utilization of the rest of the coping resources.

    CONCLUSION: Persons with traumatic spinal cord injury can survive for a relatively long time despite the hostile environment. Coping with these environments requires the employment of various coping resources, acceptance being the most important.

  • Li, Yang
    et al.
    University of Alberta.
    Kim, Amy
    University of Alberta.
    El-Basyouny, Karim
    University of Alberta.
    A resource scheduling decision support model for mobile photo enforcement2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A mobile photo enforcement (MPE) program deploys enforcement resources (equipment and personnel) to roadway locations, using radar and license plate photos to “catch” speed-limit violators. Where and when to deploy MPE program resources is a very important part of MPE operations, which helps enforcement agencies emphasize their road safety improvement goals and helps increasing the efficiency of program resource use. However, the design of MPE programs has received little attention from researchers.

    The allocation of MPE resources is a complex process. This complexity arises from the fact that the allocation of MPE resources is not stationary, but it requires moving those resources from one site to another. Therefore, when MPE program managers allocate operators and equipment to sites, they must simultaneously consider the location of the resource allocation, the time of the allocation, and the availability of resource. Due to this complexity, a tool that can assist MPE program managers in making an effective and efficient resource deployment plan becomes necessary.

  • Park, Sangung
    et al.
    University of Seoul.
    Lee, Seungjae
    University of Seoul.
    Kim, Jooyoung
    University of Seoul.
    Avoidable collision controls under a connected and autonomous vehicles environment2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

     Because all travelers want an efficient and comfortable trip, many engineers and researchers related to automotive technologies have improved their technologies. Two important technologies, connected vehicle environment (CV environment) and autonomous vehicles(AV), are considered to satisfy two properties, which are called ADAS (Advanced Driver assistance system). CV communicates with other vehicles, vehicle management, and connection to other advanced technologies under radio communication environment and shows driver various information of road condition, accident warning, traffic congestion prediction, and nearby vehicle’s kinematic information. While, sensors of AV recognizes nearby information through innate various sensors, called sensor fusion and judge the next path.

    However, these two technologies have their own weakness. CV shows too much information so drivers can’t embrace all information and have many difficulties of judging the driver’s behavior properly. Range of AV’s sensor is nearly the same as the range of vision so AV can’t perceive macroscopic traffic flows. To compensate the defect, automotive technologies tend to be the integrated technologies of connected environment and autonomous vehicles, called connected and autonomous vehicles(CAVs)

    CAVs judge and drive themselves by using the vehicle and road information through the CAV environment and/or vehicle sensors. Among CAV technologies, this paper concentrate on two main technologies: Adaptive cruise control(ACC) and cooperative adaptive cruise control (CACC), which is related to collision controls. ACC and CACC keep the time headway between an ego vehicle and a following vehicle. Therefore, the complexity and diversity of the information obtained by CAVs have resulted in the combination of many sensitive components.

    The combination of many sensitive components, which is related to reliability of technologies, causes CAVs malfunction. Malfunction of CAVs can normally affect vast harm of travelers so various safety standards are adopted to check the safety and minimize the malfunction. Many skeptics of CAVs raise a question about the reliability of CAVs. Therefore, CAV has to adopt its own safety standards. Automotive safety integrity level(ASIL) is a risk evaluation standard for only autonomous vehicles defined by the ISO 26262 – functional safety for road vehicles standard. ASIL is the combination of severity, exposure and controllability. This is a new adaptation of the safety integrity level (IEC 61508) for the automotive industry. ASIL is classified from A (Lowest safety) to D (Highest safety). ASIL D refers to the highest classification of initial hazard and to that standard’s most stringent level of safety measures to apply for avoiding an unreasonable residual risk.

    This paper proposes theoretical methods to suggest proper time headway range by velocity to prevent collision controls. This paper formulates time-invariant headway and evaluates the proper headway range of CAV technologies using string stability theory. We simulate three available cases (No ADAS, ACC, and CACC cases) to investigate effects of the malfunction of CAV’s two main technologies (ACC and CACC). The contribution of this paper is to simulate proper headway range and time-invariant failure probability under CAV environment

  • Lee, JooHyeong
    et al.
    Kagawa University, Japan.
    Ozaki, Ikumi
    Kagawa University, Japan.
    Suzuki, Keisuke
    Kagawa University, Japan.
    Nakajima, Masumi
    Yamaha Motor Co.
    Evaluation of accident avoidance supporting system at intersections for motorcyclists using ADAS2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recently in the world, Technologies using V2I(Vehicle-to-Infrastructure), V2V(Vehicle-to-Vehicle), etc. based on ICT(Information and Communication Technologies) are being developed as a system for driving safety. Those systems are designed to prevent traffic accidents by connecting all things using the internet, such as vehicles to vehicles, vehicles to peoples, vehicles to roads. In Japan, traffic systems using IT(Information Technology) are being developed as ITS(Intelligent Transport Systems). To prevent traffic accidents, autonomous control systems such as CMBS(Collision Mitigation Brake System), LKA(Lane Keeping Assist system), and ACC(Adaptive Cruise Control system) are being put to practical use in the market. However, the development of accident prevention systems for motorcycles with high traffic accident rates and high mortality rates is not active. In this paper, we propose and evaluate an HMI(Human Machine Interface) system that presents visual and auditory information as simple information to prevent traffic accidents by using ITS. This study was carried out on the assumption that the system provides an intuitive notification to the riders for the assistance in decelerating and stopping when their dangerous situations that could not be detected during riding. Therefore, the system should present information at the right time according to the situation. As a research method, we investigated the driving behavior of 30 male subjects in their 20's using a riding simulator applied the accident avoidance supporting system. And it used the scenarios involving scenarios #1 and #2, dummy scenarios, and malfunction scenario. And evaluated the effectiveness of the system through the results of critical parameters and accident probability. As a result, the brake reaction time and average deceleration decreased when using the system, and it is possible to stop the vehicle more safely. We evaluated the system is effective from reduced accident probability when using the system. This system was designed to prevent intersection accidents. Those accidents represent more than 70% of the motorcycle accident rate in Japan.

  • Lee, Jaeyoung
    et al.
    University of Central Florida.
    Abdel-Aty, Mohamed
    University of Central Florida.
    Wang, Jung-Han
    University of Central Florida.
    Lee, Chanyoung
    University of Central Florida.
    Impacts of helmet law changes on motorcyclists' fatalities in the United States2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A motorcycle helmet has been considered a very important safety equipment for motorcyclists as it prevents or minimizes head and traumatic brain injuries which are often fatal. Hence, most of the states in the United States have enacted a law requiring all motorcyclists to wear helmets in the 1960s and 1970s, which is also known as the Universal Helmet Law (UHL). Nevertheless, some states began to repeal or restrict the law since then. After several years, one state has re-enacted the UHL as it has realized that the law was quite effective in reducing motorcycle fatalities. There have been three states with changes in their helmet laws in the 2000s. Florida and Pennsylvania repealed the UHL in 2000 and 2003, respectively, and they only require underage motorcycle riders to wear helmets. In contrast, Louisiana re-enacted the UHL in 2004. The prior studies have consistently discovered that the UHL repeal put motorcyclists in danger whereas the re-enactment significantly increases helmet-use and decreases motorcycle fatalities. Nevertheless, the prior studies have only evaluated short-term effects of the law change mostly using the traditional before-after approach (it is called naïve before-and-after study). The naïve approach assumes that there is no change from the ‘before’ to ‘the after’ period that affected the safety of the entity under scrutiny; hence, the naïve approach is not able to account for the passage of time and its effect on other factors such as exposure, maturation, trend, and regression-to-the-mean bias.

    In order to account for the influence of a variety of external causal factors that change over time, the before-and-after study with comparison group and the before-and-after study with Empirical Bayes (EB) approaches are adopted in this research. A series of SPFs (safety performance functions) were estimated for motorcycle crashes using county-based data. The expected numbers of crashes were calculated using the SPFs to estimate more dependable CMFs (crash modification factors). The authors have attempted to explore the long-term impacts of repeal and reinstatement of the universal helmet law by using 13 to 16 years of data. A range of safety performance functions were developed based on counties and calculated the expected motorcycle fatal crashes.

  • Wallén Warner, Henriette
    et al.
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Mobilitet, aktörer och planering, MAP.
    Patten, Christopher
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Mobilitet, aktörer och planering, MAP.
    An evaluation of re-designed rural roads2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Sweden, there is a strong political desire to shift car traffic to cycling. While the number of road fatalities among motor vehicle occupants have seen a substantial decrease, the same positive trend has, not been found among cyclists. To increase safe cycling, different traffic safety measures is therefore needed. One such attempt is the Swedish Transport Administration’s re-design of five rural road-segments in the southern part of Sweden. On the re-designed segments, the hard shoulders on each side of the road are broadened to give more space to cyclists. At the same time, the area for motor vehicles is narrowed to a single lane where the motor vehicle drivers are forced to adapt their driving to the flow of cyclists when meeting another motor vehicle. The aim of the present study was to evaluate these re-designed rural road segments, focusing on the beliefs underpinning the road users’ attitude, subjective norm and perceived behavioural control associated with these segments.

  • Hong, Sungmin
    et al.
    Korea Transportation Safety Authority.
    Kim, Joonki
    Korea Research Institute for Human Settlements.
    Oh, Cheol
    Hanyang University.
    Ulfarsson, Gudmundur F.
    University of Iceland.
    Daylight, twilight, and night variation in road environment-related freeway traffic crashes in Korea2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    There have been numerous studies of traffic crashes that analyze the relationship of crashes with traffic conditions, the road geometry, and environment. The present paper aims to systematically investigate the possible differences in the effects of those variables during night, twilight or day. Previous studies show there is a relationship between traffic crash frequency, injury severity, and the time of day. Also, research shows that driving is different depending on the time of day. Recent work using a driving simulator has found that there is a significant driving speed differential between night and day and concludes that roadway geometric conditions that are safe during day may not be safe during nighttime driving. Much of the research that considers differences between night and day driving focuses on driver-specific characteristics such as drunk driving, young drivers, age and gender, sleepiness, but omits a systematic investigation of daytime vs. night differences in road environment variables.

    The main contribution of this paper is therefore an investigation of the effect of road environment conditions on crashes under different light conditions, using random parameter Poisson and negative binomial regressions which are estimated separately for each light condition (daytime, nighttime, twilight) and the whole 24-hour day.