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  • 2951.
    Aidi, Laili
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Tollmar, Konrad
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Blennerud, Greger
    Ericsson.
    Competing or Aligning? Assessment for Telecom Operator's strategy to address OTT TV/Video services2012Conference paper (Refereed)
    Abstract [en]

    Up until recently, it was rarely direct competition between telecom operators, cable and satellite Pay-TV providers in digital TV/Video, as their business area were different and value chain was well established. However, technology advance has altered digital TV/Video landscape, made these Communication Service Providers (CSPs) cross other’s area and opened door for new actor (OTT player) to enter the market. This triggers second change in the landscape, as it potentially bypasses CSP’s role in digital media value chain.

    There are generic potential options for telecom operator to address OTT service‘s treat, where the trend shows gradual shifts toward allowing or promoting. This study assesses telecom operator’s reaction strategies to react to this digital TV/Video convergence trend. Our analysis reveals two typical relation patterns in the value network, used by telecom operators based on strategy options above, which are ”point-to-point” and ”point-to-multipoint” relation model. We explore the underlining motivations that based these strategies, as well as analysis of the eco-systems: actors identification, business roles and distributed responsibilities among them, where we use ARA (Actors, Resource, Activities) point of view to model these value networks.

  • 2952. Aiempanakit, Montri
    et al.
    Aijaz, Asim
    Lundin, Daniel
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Helmersson, Ulf
    Kubart, Tomas
    Understanding the discharge current behavior in reactive high power impulse magnetron sputtering of oxides2013In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 113, no 13, p. 133302-Article in journal (Refereed)
    Abstract [en]

    The discharge current behavior in reactive high power impulse magnetron sputtering (HiPIMS) of Ti-O and Al-O is investigated. It is found that for both metals, the discharge peak current significantly increases in the oxide mode in contrast to the behavior in reactive direct current magnetron sputtering where the discharge current increases for Al but decreases for Ti when oxygen is introduced. In order to investigate the increase in the discharge current in HiPIMS-mode, the ionic contribution of the discharge in the oxide and metal mode is measured using time-resolved mass spectrometry. The energy distributions and time evolution are investigated during the pulse-on time as well as in the post-discharge. In the oxide mode, the discharge is dominated by ionized oxygen, which has been preferentially sputtered from the target surface. The ionized oxygen determines the discharge behavior in reactive HiPIMS.

  • 2953. Aier, Stephan
    et al.
    Buckl, Sabine
    Franke, Ulrik
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Gleichauf, Bettina
    Johnson, Pontus
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Närman, Per
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Schweda, Christian M.
    Ullberg, Johan
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    A Survival Analysis of Application Life Spans based on Enterprise Architecture Models2009In: Proc. 3rd International Workshop on Enterprise Modelling and Information Systems Architectures, EMISA 2009, 2009, Vol. P-152, p. 141-154Conference paper (Refereed)
    Abstract [en]

    Modern enterprises face the challenge to survive in an ever changing environment. One commonly accepted means to address this challenge and further enhance survivability is enterprise architecture (EA) management, which provides a holistic model-based approach to business/IT alignment. Thereby, the decisions taken in the context of EA management are based on accurate documentation of IT systems and business processes. The maintenance of such documentation causes high investments for enter-prises, especially in the absence of information on the change rates of different systems and processes. In this paper we propose a method for gathering and analyzing such in-formation. The method is used to analyze the life spans of the application portfolio of three companies from different industry sectors. Based on the results of the three case studies implications and limitations of the method are discussed.

  • 2954. Aier, Stephan
    et al.
    Ekstedt, MathiasKTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.Matthes, FlorianProper, ErikSanz, Jorge
    Trends in Enterprise Architecture Research and Practice-Driven Research on Enterprise Transformation: 7th Workshop, TEAR 2012, and 5th Working Conference, PRET 2012, Held at The Open Group Conference 2012, Barcelona, Spain, October 23-24, 2012. Proceedings2012Conference proceedings (editor) (Refereed)
  • 2955. Aigelsperger, Lisa
    et al.
    Kummer, Susanne
    Milestad, Rebecka
    Department of Urban and Rural Studies, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Vogl, Christian R.
    Chowdhury, A.
    Knowledge systems, innovations and social learning in organic farming: An Overwiev2010In: Proceedings of the 9th European IFSA Symposium, 2010, p. 664-669Conference paper (Refereed)
  • 2956.
    Aigner, Joachim Felix
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Environmental Implications of Media Consumption embedded in Digital Ecosystems: A bottom-up systems approach to the perennial case of paperless reading in Germany2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Digitalization has been reshaping the media landscape in recent years, often conveying an implicit promise of becoming less dependent on physical resources. At the same time, the current understanding of digital reading goes beyond dedicated e-readers or definable digital media products such as magazines or newspapers. In fact, it must be perceived as a function or service obtained from existing and ever-expanding “digital ecosystems”. There is furthermore a clear and unambiguous trend that relatively small and mobile devices are on the rise for consuming all kinds of media.

    Next to potentially enabling environmental gains compared to traditional paper-based media consumption, there are agreeing indications of a shift from overall electricity consumption dominated by end-user devices towards an increasing importance of less tangible data transmission networks and data centers. Therefore, a bottom-up analysis is deemed to compliment more general top-down observations and assessments. To this end, an elaborated reference scenario is proposed as to bridge the mere analytical method of Life Cycle Assessment (LCA) with behavioral aspects based on German market observations and surveys. The prevailing aim of this study is to detect environmental hot-spots and absolute impacts linked to the service of accessing text-based content via connected electronic devices. In doing so, this study takes the position that both types of media consumption – digital and paper-based - are incommensurable due to the very evident differences in provided functions, markets, and industries. Therefore, an attributional and stand-alone LCA is considered appropriate.

    The perceived current situation (reference scenario) evolves around substantiated estimates and assumptions concerning production of devices, use of devices as well as operation of essential data transmission network components. Looking at potential hot-spots, electricity consumption linked to data transmission could be a decisive factor for the environmental performance of digital reading. However, the actual importance of data transmission infrastructures depends on both methodological choices and a range of parameters or trends. For instance, the relative importance is shifted when more recent estimates of electricity intensities are incorporated. Depending on actual and localized electricity intensity of data transmission, the amount of data required to provide an expected function may inhibit environmental potentials of digital media consumption.

    Postulating average annual consumption of digital contents and assuming actual substitution of equivalent printed media products, about 50 kg CO2-equivalents. could potentially be avoided. This theoretical potential is based on the calculated global warming potential (GWP) associated with digital reading according to the reference scenario which amounts to about 29 kg CO2-equivalents. Therefore, this study supports findings from previous studies that indicated environmental benefits of digital reading.

    Compared to other functions or services (e.g. video/music streaming, podcasts, audio books) embedded in the same “digital ecosystems”, reading requires little amount of data. If allocation of upstream effects is based on time, the relative importance of data transmission networks could be gauged and compared by adopting a “data-to-service time” ratio. Taking the reference scenario as a starting point, a perceivable ratio for digital reading is 0.015 GB/h, including systemic inefficiencies. In contrast, streaming of high-definition video contents can easily consume 3 GB/h, a 200-fold increase.

    The audience of this study comprises providers of digital reading services and/or other media services as well as end-users as integral element in “digital ecosystems”. Besides, the report proposes a conceptual assessment framework which can be applied to other contemporary digital services or functions.

  • 2957. Aijaz, Asim
    et al.
    Sarakinos, Kostas
    Lundin, Daniel
    Brenning, Nils
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Helmersson, Ulf
    A strategy for increased carbon ionization in magnetron sputtering discharges2012In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 23, p. 1-4Article in journal (Refereed)
    Abstract [en]

    A strategy that facilitates a substantial increase of carbon ionization in magnetron sputtering discharges is presented in this work. The strategy is based on increasing the electron temperature in a high power impulse magnetron sputtering discharge by using Ne as the sputtering gas. This allows for the generation of an energetic C+ ion population and a substantial increase in the C+ ion flux as compared to a conventional Ar-HiPIMS process. A direct consequence of the ionization enhancement is demonstrated by an increase in the mass density of the grown films up to 2.8 g/cm(3); the density values achieved are substantially higher than those obtained from conventional magnetron sputtering methods.

  • 2958.
    Aikaterini, Micheli
    KTH, School of Computer Science and Communication (CSC).
    Impact of IoT Enabled Service Solutions in the Downstream Automotive Supply Chain2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The automotive industry has been an integral element of global economy for many decades and has withstood economic downturns by being able to shift their processes along with market needs. With the addition of new innovations in the field of ICT, the automotive industry has addressed the need to restructure to stay afront of customers‘ expectation. Internet of Things and Big Data have advanced to where connected solutions are possible to provide value opportunities in many industries including automotives with the entrance of connected vehicles.

    This thesis aims to investigate the extent that connected services could be applied to the downstream automotive supply chain as a viable long-term business solution. A door-to-door perspective was applied in order to identify the challenges and opportunities towards different stakeholders within this supply chain. Qualitative interviews were conducted with leading OEMs, Logistics Providers, NSC, and car dealers as well as quantitative analysis performed on car buying customers to gauge their opinions of connected vehicles and services.

    There are many opportunities for a viable connected service solution to offer additional value to each stakeholder including efficient supply chain management due to increased visibility, improved lead times, and operational effectiveness. However, with the complexity and variations in the supply chain it cannot be applied rapidly and requires all actors to agree to participation in a network that supports the IT infrastructures and fortifies information flow.

  • 2959. Aikio, A T
    et al.
    Blomberg, Lars
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Marklund, Göran
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Yamauchi, M
    On the origin of the high-altitude electric field fluctuations in the auroral zone1996In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 101, no A12, p. 27157-27170Article in journal (Refereed)
    Abstract [en]

    Intense fluctuations in the electric field at high altitudes in the auroral zone are frequently measured by the Viking satellite. We have made an analysis of the origin of electric and magnetic fluctuations in the frequency range of 0.1 - 1 Hz by assuming four different sources for the signals: (I) spatial structures, (2) spatial structures with a parallel potential drop below the satellite, (3) traveling; shear Alfven waves, and (4) interfering shear Alfven waves. We will shaw that these different sources of the signals may produce similar amplitude ratios and phase differences between the perpendicular electric and magnetic fields. Since the different sources have different frequency dependencies, this can be used as an additional test if the signals are broadband. In other cases, additional information is needed, for example, satellite particle measurements or ground; magnetic measurements. The ideas presented in the theory were tested for one Viking eveningside pass over Scandinavia, where ground-based magnetometer and EISCAT radar measurements were available. The magnetic conditions were active during this pass and several interfering shear Alfven waves were found. Also, a spatial structure with a parallel potential drop below the satellite was identified. The magnitude of the 10-km-wide potential drop was at least 2 kV and the upward field-aligned current 26 mu A m(-2) (value mapped to the ionospheric level). The held-aligned conductance was estimated as 1.3 - 2.2x10(-8) S m(-2).

  • 2960. Aikio, A. T.
    et al.
    Mursula, K.
    Buchert, S.
    Forme, F.
    Amm, O.
    Marklund, Göran T.
    KTH, Superseded Departments, Alfvén Laboratory.
    Dunlop, M.
    Fontaine, D.
    Vaivads, A.
    Fazakerley, A.
    Temporal evolution of two auroral arcs as measured by the Cluster satellite and coordinated ground-based instruments2004In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 22, no 12, p. 4089-4101Article in journal (Refereed)
    Abstract [en]

    The four Cluster s/c passed over Northern Scandinavia on 6 February 2001 from south-east to north-west at a radial distance of about 4.4 R-E in the post-midnight sector. When mapped along geomagnetic field lines, the separation of the spacecraft in the ionosphere was confined to within 110 km in latitude and 50 km in longitude. This constellation allowed us to study the temporal evolution of plasma with a time scale of a few minutes. Ground-based instrumentation used involved two all-sky cameras, magnetometers and the EISCAT radar. The main findings were as follows. Two auroral arcs were located close to the equatorward and poleward edge of a large-scale density cavity, respectively. These arcs showed a different kind of a temporal evolution. (1) As a response to a pseudo-breakup onset, both the up- and downward field-aligned current (FAC) sheets associated with the equatorward arc widened and the total amount of FAC doubled in a time scale of 1-2 min. (2) In the poleward arc, a density cavity formed in the ionosphere in the return (downward) current region. As a result of ionospheric feedback, a strongly enhanced ionospheric southward electric field developed in the region of decreased Pedersen conductance. Furthermore, the acceleration potential of ionospheric electrons, carrying the return current, increased from 200 to 1000 eV in 70 s, and the return current region widened in order to supply a constant amount of return current to the arc current circuit. Evidence of local acceleration of the electron population by dispersive Alfven waves was obtained in the upward FAC region of the poleward arc. However, the downward accelerated suprathermal electrons must be further energised below Cluster in order to be able to produce the observed visible aurora. Both of the auroral arcs were associated with broad-band ULF/ELF (BBELF) waves, but they were highly localised in space and time. The most intense BBELF waves were confined typically to the return current regions adjacent to the visual arc, but in one case also to a weak upward FAC region. BBELF waves could appear/disappear between s/c crossings of the same arc separated by about 1 min.

  • 2961. Aikio, A. T.
    et al.
    Pitkanen, T.
    Fontaine, D.
    Dandouras, I.
    Amm, O.
    Kozlovsky, A.
    Vaivads, Andris
    Uppsala universitet, Institutet för rymdfysik, Uppsalaavdelningen.
    Fazakerley, A.
    EISCAT and Cluster observations in the vicinity of the dynamical polar cap boundary2008In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 26, no 1, p. 87-105Article in journal (Refereed)
    Abstract [en]

    The dynamics of the polar cap boundary and auroral oval in the nightside ionosphere are studied during late expansion and recovery of a substorm from the region between Tromso (66.6 degrees cgmLat) and Longyearbyen (75.2 degrees cgmLat) on 27 February 2004 by using the coordinated EISCAT incoherent scatter radar, MIRACLE magnetometer and Cluster satellite measurements. During the late substorm expansion/early recovery phase, the polar cap boundary (PCB) made zig-zag-type motion with amplitude of 2.5 degrees cgmLat and period of about 30 min near magnetic midnight. We suggest that the poleward motions of the PCB were produced by bursts of enhanced reconnection at the near-Earth neutral line (NENL). The subsequent equatorward motions of the PCB would then represent the recovery of the merging line towards the equilibrium state (Cowley and Lockwood, 1992). The observed bursts of enhanced westward electrojet just equatorward of the polar cap boundary during poleward expansions were produced plausibly by particles accelerated in the vicinity of the neutral line and thus lend evidence to the Cowley-Lockwood paradigm. During the substorm recovery phase, the footpoints of the Cluster satellites at a geocentric distance of 4.4 R-E mapped in the vicinity of EISCAT measurements. Cluster data indicate that outflow of H+ and O+ ions took place within the plasma sheet boundary layer (PSBL) as noted in some earlier studies as well. We show that in this case the PSBL corresponded to a region of enhanced electron temperature in the ionospheric F region. It is suggested that the ion outflow originates from the F region as a result of increased ambipolar diffusion. At higher altitudes, the ions could be further energized by waves, which at Cluster altitudes were observed as BBELF (broad band extra low frequency) fluctuations. The four-satellite configuration of Cluster revealed a sudden poleward expansion of the PSBL by 2 degrees during similar to 5 min. The beginning of the poleward motion of the PCB was associated with an intensification of the downward FAC at the boundary. We suggest that the downward FAC sheet at the PCB is the high-altitude counterpart of the Earthward flowing FAC produced in the vicinity of the magnetotail neutral line by the Hall effect (Sonnerup, 1979) during a short-lived reconnection pulse.

  • 2962.
    Ailenei, Ivona
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Kahn Skola2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The building is searching for the site’s existing landscape with it’s forests and an existing hidden glade that becomes the core of the project.

    The school is a place which is meant to be discovered step by step, in order to increase the creativity. And it acts like a heart, where the circle becomes a symbol for interaction and movement through the parts of the programme and the surroundings. 

    The building has its heart where the existing glade 

    exists.There are the smaller children, the kindergarden and the dining room which are directed outward. 

    A new , bigger glade is built for the children from the upper classes. This acts also as a social act between the society and the school. The big circle activates the place and takes the 

    children through all parts of the program. There will be an

    challenging investigation to move from the classrooms to the dining room and then to the school garden or the 

    workshops. 

    The classrooms take an articulated form that also

    encourages the idea of that  everyone should find her/his own place and provides a place for everyone.

    The workshops which are located on the ground floor open up to room where they can extend to the exterior  and where the children can work and have acces to the outside and where they can be seen and appreciated.

  • 2963.
    Ailert, Sebastian
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Bevarat boende, Skapat boende: Transformation Tyresö2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    What is a transformation, and what could it be? How could a strategy for how to approach a transformation project look?

    I have defined a transformation as the act of taking an existing building and inserting a new program that creates a new reality.

    There can be many reasons to do a transformation instead of building something new. The most important reason that I have chosen to work with is about capturing the qualities or values that exists in a building and bring them into the new reality and build on them instead of creating whole different values. Values in this case are things like surface area, volumes, height, light conditions, material and details. It is things like the cast concrete stairs and the very special windows in some parts of the building. To me this is the core idea and purpose of any transformation.

    Because the values that are kept ties the present to the history, and carries and keeps memories and identities. They create continuity in the story of the building.

    In a transformation a number of mayor conflicts arise because the new program demands values that the existing building lacks. How you chose to solve these conflicts is the most critical and most difficult aspect of any transformation.

    My transformation is done two steps. The first step is about identifying as much values as possible and trying to bring them into the new program while overlooking the whole. The dwelling was there already, all I had to do was isolate the values and bring them in to the new program. I have kept as much of the existing material as possible to keep the values intact and only added walls to define the new apartments. The result is very particular dwellings; a lot of them have their own entrances, they are spreading out both horizontally and vertically and have sunlight from two directions.

    This is a safe and rather easy way of keeping values. When these kept dwellings are defined the more difficult conflicts arises that makes the transformation so interesting. The surface areas that remain after I have laid out these kept dwellings are hard to create good dwellings from.

    I think it’s important that the additions that has to be made in a transformation relates to the building that used to be. Otherwise there´s a great risk that the existing values are destroyed.

    Relation for me is about picking up things like spatial concepts and concepts relating to form, material or structure.

    The courtyards that exist today are rarely in use. Courtyards are actually something amazing. They don’t only retract sunlight but also shadow, rain, snow, sounds, foliage, bugs and birds deep into a building. Therefore I have chosen to develop the courtyards that already exists by adding some more. In and around the school there are also several stairs in cast concrete. To create connections I’ve added new similar stairs.  

    A good transformation creates the conditions needed for a new demand, while keeping the most important values in a building and adds to the identity instead of destroying it.  

    My strategy for transformations in two steps is about first bringing certain special values into a new program without considering the building as a whole. Afterwards an addition is created which relates to the existing while solving the conflicts that always arise when doing a transformation.

    The result in this case is dwellings that are very particular compared to the dwellings which are usually built today. They are not standard flats but dwellings with surface areas, volumes, details and other characteristics that newly built dwellings rarely has.

  • 2964. Aili, K.
    et al.
    Nyman, Teresia
    KTH, School of Technology and Health (STH).
    Hillert, L.
    Svartengren, M.
    Sleep disturbances predict future sickness absence among individuals with lower back or neck-shoulder pain: A 5-year prospective study2015In: Scandinavian Journal of Public Health, ISSN 1403-4948, E-ISSN 1651-1905, Vol. 43, no 3, p. 315-323Article in journal (Refereed)
    Abstract [en]

    Background: Musculoskeletal pain is one of the most common causes of sickness absence. Sleep disturbances are often co-occurring with pain, but the relationship between sleep and pain is complex. Little is known about the importance of self-reported sleep, when predicting sickness absence among persons with musculoskeletal pain. This study aims to study the association between self-reported sleep quality and sickness absence 5 years later, among individuals stratified by presence of lower back pain (LBP) and neck and shoulder pain (NSP). Methods: The cohort (n = 2286) in this 5-year prospective study (using data from the MUSIC-Norrtälje study) was stratified by self-reported pain into three groups: no LBP or NSP, solely LBP or NSP, and oncurrent LBP and NSP. Odds ratios (ORs) for the effect of self-reported sleep disturbances at baseline on sickness absence (> 14 consecutive days), 5 years later, were calculated. Results: Within all three pain strata, individuals reporting the most sleep problems showed a significantly higher OR for all-cause sickness absence, 5 years later. The group with the most pronounced sleep problems within the concurrent LBP and NSP stratum had a significantly higher OR (OR 2.00; CI 1.09-3.67) also for long-term sickness absence (> 90days) 5 years later, compared to the group with the best sleep. Conclusions: Sleep disturbances predict sickness absence among individuals regardless of co-existing features of LBP and/or NSP. The clinical evaluation of patients should take possible sleep disturbances into account in the planning of treatments.

  • 2965.
    Aili, Katarina
    KTH, School of Technology and Health (STH), Ergonomics.
    Med uppstyckat arbete: En studie som mäter stress bland ackords- och linjestyckare2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna jämförande studie på magisternivå gjordes bland styckare på ett företag i Sverige. Studien gjordes i syfte att utreda hur styckare påverkas av de två vanligast förekommande arbetsuppläggen - arbete vid enkelbord och arbete vid linje. Åtta styckare deltog i studien. Ena veckan arbetade deltagarna vid enkelbord, med ackordslön, andra veckan arbetade de vid linje med maskinstyrt tempo, med lön som sätts utifrån takten på bandet. Stress mättes subjektivt med stress-energi-formuläret. Hjärtfrekvens mättes och jämfördes mellan de olika arbetsuppläggen. Observationer och intervjuer av samtliga deltagare utfördes.

    Skillnaden i arbetsuppläggen består i att styckarna vid enkelbord styckar en större del av grisen, att de väljer tempo själva samt att de arbetar ackordstyrt. Vid linje arbetar styckarna på löpande band under maskinstyrd arbetstakt, de har kortare arbetscykel och mer styrt arbete. Lönen vid linje sätts utifrån takten på bandet.

    En signifikant högre hjärtfrekvens uppmättes vid arbete, samt under pauser, då styckarna arbetade vid enkelbord jämfört med vid linje. Resultatet av svaren på stress-energi-formuläret visade något högre skattad stress vid linje och något högre skattad energi vid enkelbord. Skillnaden var inte signifikant. Beträffande intervjuerna uppgav fyra av åtta att de kände sig mer stressade vid linjearbetet, en av åtta att han kände sig mer stressad vid enkelbord. Fyra av åtta upplevde att de hade mer besvär i nacke/skuldra/rygg efter arbete vid linje, en upplevde mer besvär i nacke/skuldra/rygg efter arbete på enkelbord.

    Endast en av deltagarna uppmätte högre hjärtfrekvens vid arbete och paus vid linje än vid enkelbord. Samma deltagare upplevde arbetet vid linje som mer stressande, samt hade mer besvär av smärta efter arbete vid linje.

    Arbetsbelastningen mätt som hjärtfrekvens verkar således vara högre vid enkelbord. Däremot upplevde fler styckare mer stress och mer besvär i nacke/skuldra/rygg efter arbete vid linje. Det finns det anledning att tro att andra faktorer än den rena mekaniska belastningen styckarna utsätts för i sitt arbete kan vara en bidragande faktor vid besvärsförekomst.

  • 2966. Aimable, Anne
    et al.
    Doubi, Herve Goure
    Stuer, Michael
    Zhao, Zhe
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Bowen, Paul
    Synthesis and Sintering of ZnO Nanopowders2017In: TECHNOLOGIES, ISSN 2227-7080, Vol. 5, no 2, article id 28Article in journal (Refereed)
    Abstract [en]

    Nanopowders are continuously under investigation as they open new perspectives in numerous fields. There are two main challenges to stimulating their development: sufficient low-cost, high throughput synthesis methods which lead to a production with well-defined and reproducible properties; and for ceramics specifically, the conservation of the powders' nanostructure after sintering. In this context, this paper presents the synthesis of a pure nanosized powder of ZnO (dv(50)similar to 60 nm, easily redispersable) by using a continuous Segmented Flow Tubular Reactor (SFTR), which has previously shown its versatility and its robustness, ensuring a high powder quality and reproducibility over time. A higher scale of production can be achieved based on a "scale-out" concept by replicating the tubular reactors. The sinterability of ZnO nanopowders synthesized by the SFTR was studied, by natural sintering at 900 degrees C and 1100 degrees C, and Spark Plasma Sintering (SPS) at 900 degrees C. The performance of the synthesized nanopowder was compared to a commercial ZnO nanopowder of high quality. The samples obtained from the synthesized nanopowder could not be densified at low temperature by traditional sintering, whereas SPS led to a fully dense material after only 5 min at 900 degrees C, while also limiting the grain growth, thus leading to a nanostructured material.

  • 2967.
    Ainomae, Ahti
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Bengtsson, Mats
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Trump, Tonu
    Tallinn Univ Technol, Dept Radio & Telecommun Engn, EE-12616 Tallinn, Estonia..
    Distributed Largest Eigenvalue-Based Spectrum Sensing Using Diffusion LMS2018In: IEEE TRANSACTIONS ON SIGNAL AND INFORMATION PROCESSING OVER NETWORKS, ISSN 2373-776X, Vol. 4, no 2, p. 362-377Article in journal (Refereed)
    Abstract [en]

    In this paper, we propose a distributed detection scheme for cognitive radio (CR) networks, based on the largest eigenvalues (LEs) of adaptively estimated correlation matrices (CMs), assuming that the primary user signal is temporally correlated. The proposed algorithm is fully distributed, there by avoiding the potential single point of failure that a fusion center would imply. Different forms of diffusion least mean square algorithms are used for estimating and averaging the CMs over the CR network for the LE detection and the resulting estimation performance is analyzed using a common framework. In order to obtain analytic results on the detection performance, the exact distribution of the CM estimates are approximated by a Wishart distribution, by matching the moments. The theoretical findings are verified through simulations.

  • 2968.
    Ainomäe, Ahti
    KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Distributed Detection in Cognitive Radio Networks2017Licentiate thesis, monograph (Other academic)
    Abstract [en]

    One of the problems with the modern radio communication is the lack of availableradio frequencies. Recent studies have shown that, while the available licensed radiospectrum becomes more occupied, the assigned spectrum is significantly underutilized.To alleviate the situation, cognitive radio (CR) technology has been proposedto provide an opportunistic access to the licensed spectrum areas. Secondary CRsystems need to cyclically detect the presence of a primary user by continuouslysensing the spectrum area of interest. Radiowave propagation effects like fading andshadowing often complicate sensing of spectrum holes. When spectrum sensing isperformed in a cooperative manner, then the resulting sensing performance can beimproved and stabilized.

    In this thesis, two fully distributed and adaptive cooperative Primary User (PU)detection solutions for CR networks are studied.

    In the first part of this thesis we study a distributed energy detection schemewithout using any fusion center. Due to reduced communication such a topologyis more energy efficient. We propose the usage of distributed, diffusion least meansquare (LMS) type of power estimation algorithms with different network topologies.We analyze the resulting energy detection performance by using a commonframework and verify the theoretical findings through simulations.

    In the second part of this thesis we propose a fully distributed detection scheme,based on the largest eigenvalue of adaptively estimated correlation matrices, assumingthat the primary user signal is temporally correlated. Different forms of diffusionLMS algorithms are used for estimating and averaging the correlation matrices overthe CR network. The resulting detection performance is analyzed using a commonframework. In order to obtain analytic results on the detection performance, theadaptive correlation matrix estimates are approximated by a Wishart distribution.The theoretical findings are verified through simulations.

  • 2969.
    Ainomäe, Ahti
    et al.
    KTH, School of Electrical Engineering (EES), Information Science and Engineering. Tallinn University of Technology, Estonia.
    Trump, T.
    Bengtsson, Mats
    KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Distributed largest eigenvalue detection2017In: 2017 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 3519-3523, article id 7952811Conference paper (Refereed)
    Abstract [en]

    Cognitive radio (CR) systems need to detect the presence of a primary user (PU) signal by continuously sensing the spectrum area of interest. Radiowave propagation effects like fading and shadowing often complicate sensing of spectrum holes because the PU signal can be weak in a particular area. Cooperative spectrum sensing is seen as a prospective solution to enhance the detection of PU signals. In this paper we study distributed spectrum sensing, based on the largest eigenvalue of adaptively estimated correlation matrices (CMs) of received signals. The PU signal is assumed to be temporally correlated. In this paper an Combine and Adapt (CTA) least Mean Square (LMS) diffusion based mean vector estimation scheme is proposed. No fusion center (FC) for estimation or detection is used. We analyse the resulting detection performance and verify the theoretical findings through simulations.

  • 2970.
    Ainomäe, Ahti
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. Tallinn Univ. of Technol., Tallinn, Estonia.
    Trump, Tõnu
    Tallinn Univ. of Technol., Tallinn, Estonia.
    Bengtsson, Mats
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Distributed Diffusion LMS based Energy Detection2014In: Proceedings of 6th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT), 2014, 2014, p. 176-183Conference paper (Refereed)
    Abstract [en]

    Cognitive radio (CR) is seen as a promising technology to make radio spectrum usage more effective by providing an opportunistic access for secondary users to the licensed spectrum areas. CR systems need to detect the presence of a primary user (PU) signal by continuously sensing the spectrum area of interest. Radiowave propagation effects like fading and shadowing often complicate sensing of spectrum holes because the PU signal can be weak in a particular area. Cooperative spectrum sensing is seen as a prospective solution to enhance the detection of PU signals. This paper studies distributed spectrum sensing in a cognitive radio context. We investigate distributed energy detection schemes without using any fusion center. We propose the usage of distributed, diffusion least mean square (LMS) type of power estimation algorithms. In this paper an Adapt and Combine (ATC) diffusion based power estimation scheme is proposed and the performance is compared with the Combine and Adapt (CTA) and ring-around schemes in a common framework. The PU signal is assumed to be slowly fading. We analyse the resulting energy detection performance and verify the theoretical findings through simulations.

  • 2971.
    Ainomäe, Ahti
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. Department of Radio and Telecommunication Engineering, Tallinn University of Technology, Tallinn, Estonia .
    Trump, Tõnu
    Tallin University of Technology.
    Bengtsson, Mats
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Distributed Recursive Energy Detection2014In: Proceedings of Wireless Communications and Networking Conference (WCNC), 2014, IEEE Communications Society, 2014, p. 1242-1247Conference paper (Refereed)
    Abstract [en]

    Recent studies have shown that, while the available licensed radio spectrum becomes more occupied, the assigned spectrum is significantly underutilized. To alleviate the situation, cognitive radio (CR) technology has been proposed to provide an opportunistic access to the licensed spectrum areas. CR systems are able to serve the secondary users for detecting and utilizing so called spectrum holes by sensing and adapting to the environment without causing harmful effects or interference to the licensed primary users (PU). CR systems need to detect the presence of a primary user by continuously sensing the spectrum area of interest. Radiowave propagation effects like fading and shadowing often complicate sensing of spectrum holes because the PU signal can be weak in a particular area. Cooperative spectrum sensing is seen as a prospective solution to enhance the detection of PU signals. This paper studies distributed spectrum sensing in a cognitive radio context. We investigate a distributed energy detection scheme without using any fusion center. Due to reduced communication such a topology is more energy efficient. The PU signal is assumed to be in slow fading. A recursive distributed power estimation and detection scheme is proposed. The theoretical findings are verified through simulations.

  • 2972. Airila, M. I.
    et al.
    Aho-Mantila, L.
    Brezinsek, S.
    Coad, J. P.
    Kirschner, A.
    Likonen, J.
    Matveev, D.
    Rubel, Marek
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics. KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Strachan, J. D.
    Widdowson, A.
    Wiesen, S.
    ERO modelling of local deposition of injected C-13 tracer at the outer divertor of JET2009In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T138, p. 014021-Article in journal (Refereed)
    Abstract [en]

    The 2004 tracer experiment of JET with the injection of (CH4)-C-13 into H-mode plasma at the outer divertor has been modelled with the Monte Carlo impurity transport code ERO. EDGE2D solutions for inter-ELM and ELM-peak phases were used as plasma backgrounds. Local two-dimensional (2D) deposition patterns at the vertical outer divertor target plate were obtained for comparison with post-mortem surface analyses. ERO also provides emission profiles for comparison with radially resolved spectroscopic measurements. Modelling indicates that enhanced re-erosion of deposited carbon layers is essential in explaining the amount of local deposition. Assuming negligible effective sticking of hydrocarbons, the measured local deposition of 20-34% is reproduced if re-erosion of deposits is enhanced by a factor of 2.5-7 compared to graphite erosion. If deposits are treated like the substrate, the modelled deposition is 55%. Deposition measurements at the shadowed area around injectors can be well explained by assuming negligible re-erosion but similar sticking behaviour there as on plasma-wetted surfaces.

  • 2973. Airila, M. I.
    et al.
    Jarvinen, A.
    Groth, M.
    Belo, P.
    Wiesen, S.
    Brezinsek, S.
    Lawson, K.
    Borodin, D.
    Kirschner, A.
    Coad, J. P.
    Heinola, K.
    Likonen, J.
    Rubel, Marek
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Widdowson, A.
    Preliminary Monte Carlo simulation of beryllium migration during JET ITER-like wall divertor operation2015In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 463, p. 800-804Article in journal (Refereed)
    Abstract [en]

    Migration of beryllium into the divertor and deposition on tungsten in the final phase of the first ITER-like-wall campaign of JET are modelled with the 3D Monte Carlo impurity transport code ERO. The simulation covers the inner wall and the inner divertor. To generate the plasma background for Monte Carlo tracing of impurity particles, we use the EDGE2D/EIRENE code set. At the relevant regions of the wall, the estimated plasma conditions vary around T-e approximate to 5eV and n(e) 2 x 10(17) m(-3) (far-scrape-off layer; more than 10 cm away from the LCFS). We calculate impurity distributions in the plasma using the main chamber source as a free parameter in modelling and attempt to reproduce inter-ELM spectroscopic BeII line (527 nm) profiles at the divertor. The present model reproduces the level of emission close to the inner wall, but further work is needed to match also the measured emission peak values and ultimately link the modelled poloidal net deposition profiles of beryllium to post mortem data.

  • 2974. Airila, M. I.
    et al.
    Makkonen, T.
    Järvinen, A.
    Groth, M.
    Brezinsek, S.
    Coad, J. P.
    Jachmich, S.
    Kirschner, A.
    Likonen, J.
    Meigs, A.
    Rubel, Marek
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Widdowson, A.
    Re-deposition dynamics of trace 13C in H-mode divertor conditions2013In: 40th EPS Conference on Plasma Physics, EPS 2013, 2013, p. 629-632Conference paper (Refereed)
  • 2975. Airiskallio, E.
    et al.
    Nurmi, E.
    Heinonen, M. H.
    Vayrynen, I. J.
    Kokko, K.
    Ropo, M.
    Punkkinen, M. P. J.
    Pitkanen, H.
    Alatalo, M.
    Kollar, J.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    High temperature oxidation of Fe-Al and Fe-Cr-Al alloys: The role of Cr as a chemically active element2010In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 52, no 10, p. 3394-3404Article in journal (Refereed)
    Abstract [en]

    Good high-temperature corrosion resistance of Fe-Al alloys in oxidizing environments is due to the alpha-Al2O3 film which is formed on the surface provided temperature is above 900 degrees C and the Al-content of the alloy exceeds the critical value. Ab initio calculations combined with experiments on Fe-13Al, Fe-18Al, Fe-23Al and Fe-10Cr-10Al alloys show that the beneficial effect of Cr on the oxidation resistance is significantly related to bulk effects. The comparison of experimental and calculated results indicates a clear correlation between the Fe-Cr chemical potential difference and the formation of the protective oxide scales. (C) 2010 Elsevier Ltd. All rights reserved.

  • 2976. Airiskallio, E.
    et al.
    Nurmi, E.
    Heinonen, M. H.
    Vayrynen, I. J.
    Kokko, K.
    Ropo, M.
    Punkkinen, M. P. J.
    Pitkanen, H.
    Alatalo, M.
    Kollar, J.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Third element effect in the surface zone of Fe-Cr-Al alloys2010In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 81, no 3Article in journal (Refereed)
    Abstract [en]

    The third element effect to improve the high temperature corrosion resistance of the low-Al Fe-Cr-Al alloys is suggested to involve a mechanism that boosts the recovering of the Al concentration to the required level in the Al-depleted zone beneath the oxide layer. We propose that the key factor in this mechanism is the coexistent Cr depletion that helps to maintain a sufficient Al content in the depleted zone. Several previous experiments related to our study support that conditions for such a mechanism to be functional prevail in real oxidation processes of Fe-Cr-Al alloys.

  • 2977. Airiskallio, E.
    et al.
    Nurmi, E.
    Vayrynen, I. J.
    Kokko, K.
    Ropo, M.
    Punkkinen, M. P. J.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Magnetic origin of the chemical balance in alloyed Fe-Cr stainless steels: First-principles and Ising model study2014In: Computational materials science, ISSN 0927-0256, E-ISSN 1879-0801, Vol. 92, p. 135-140Article in journal (Refereed)
    Abstract [en]

    Iron-chromium is the base material for most of the stainless steel grades. Recently, new insights into the origins of fundamental physical and chemical characteristics of Fe-Cr based alloys have been achieved. Some of the new results are quite unexpected and call for further investigations. The present study focuses on the magnetic contribution in the atomic driving forces related to the chemical composition in Fe-Cr when alloyed with Al, Ti, V, Mn, Co, Ni, and Mo. Using the ab initio exact muffin-tin orbitals method combined with an Ising-type spin model, we demonstrate that the magnetic moment of the solute atoms with the induced changes in the magnetic moments of the host atoms form the main factor in determining the mixing energy and chemical potentials of low-Cr Fe-Cr based alloys. The results obtained in the present work are related to the designing and tuning of the microstructure and corrosion protection of low-Cr steels.

  • 2978. Airiskallio, E.
    et al.
    Nurmi, E.
    Vayrynen, I. J.
    Kokko, K.
    Ropo, M.
    Punkkinen, Marko P. J.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Tuning the surface chemistry of Fe-Cr by V doping2009In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 80, no 15Article in journal (Refereed)
    Abstract [en]

    The reversal of the magnitudes of the bulk and surface chemical-potential differences induces the outburst of Cr on the otherwise pure Fe surface of Fe-Cr alloys. This threshold value for the Cr content is about 10 at. %. It is found that vanadium addition to Fe-Cr shifts the Cr threshold to a substantially lower value suggesting V having a positive effect on the corrosion resistance of low Cr steels. The obtained shift in the Cr threshold is shown to be connected to the change in volume of the alloy.

  • 2979.
    Aishwar, Ravichandran
    KTH, School of Engineering Sciences (SCI).
    Aerodynamics of Bird Flight2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    It is the objective of this thesis project to understand the physics behind the different modes of bird flight and to do numerical two dimensional simulations of pure plunging, pure pitching and combined pitch-plunging motion of an aerofoil. First, the different physical models used to understand the generation of thrust are explained. Then the numerical model used for the simulation is explained briefly. Then the results and analysis of the numerical simulations are presented.

  • 2980.
    Ait Ali, Abderrahman
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Lindberg, Per Olov
    KTH.
    Nilsson, Jan-Eric
    Eliasson, Jonas
    Aronsson, Martin
    Disaggregation in Bundle Methods: Application to the Train Timetabling Problem2017Conference paper (Refereed)
    Abstract [en]

    Bundle methods are often used to solve dual problems that arise from Lagrangian relaxations of large scale optimization problems. An example of such problems is the train timetabling problem. This paper focuses on solving a dual problem that arises from Lagrangian relaxation of a train timetabling optimization program. The dual problem is solved using bundle methods. We formulate and compare the performances of two different bundle methods: the aggregate method, which is a standard method, and a new, disaggregate, method which is proposed here. The two methods were tested on realistic train timetabling scenarios from the Iron Ore railway line. The numerical results show that the new disaggregate approach generally yields faster convergence than the standard aggregate approach.

  • 2981.
    Ait Ali, Abderrahman
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Warg, Jennifer
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Eliasson, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Measuring the Socio-economic Benefits of Train Timetables: Application to Commuter Train Services in Stockholm2017In: 20th EURO Working Group on Transportation Meeting, EWGT 2017, 4-6 September 2017, Budapest, Hungary, Elsevier, 2017, Vol. 27, p. 849-856Conference paper (Refereed)
    Abstract [en]

    On highly used railway lines with heterogeneous traffic, timetabling is challenging. In particular, the limited existing capacity means that to guarantee an acceptable level of quality, the infrastructure manager must cancel some train services on the expense of others. In this article, we study the conflict between commercial long-distance trains and subsidized commuter trains with a socio-economic perspective (i.e. travelers and train operators). The study attempts to answer the following question: What is the socio-economic effect of modifying the timetable of a commuter service?The case study treats the commuter train services in Stockholm. Trip data was collected from the local commuter train operator. An entropy maximization-based model was implemented to estimate the dynamic network Origin-Destination (OD) matrix. This dynamic matrix, of one full working day, was then used to estimate the number of travelers per train, and further converted for use in the microscopic simulation tool RailSys. Travel and waiting time are estimated for each OD pair and with that the generalized costs for the travelers and operators. The effect of crowding in the trains is included in the estimation. The article can be considered as an initiation to a novel method to calculate effects of changes in commuter train timetables. This novel approach enables to price commercial train slots in the capacity allocation process such as in an auction. It provides a new way to estimate the local train operator´s valuation of the different parameters (i.e. waiting, travel time and interchanges). Using RailSys for the estimation of times makes it possible to include capacity aspects that normally are difficult to reveal.

  • 2982.
    Ait-Ali, Abderrahman
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Integration of Production Scheduling and Energy Management: Software Development2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Demand-Side Management concepts have the potential to positively impact the financial as well as the environmental aspects of energy-intensive industries. More specifically, they allow reducing the energy cost for the industrial plants by dealing with energy-availability fluctuations.

    In this context, efficient frameworks for scheduling with energy awareness have been studied and showed potential to reduce the overall energy bill for energy-intensive industries, for instance stainless steel and paper plants. Those frameworks usually combine scheduling and energy optimization into one monolithic system. This work investigates the possibility of integrating the two systems by specific exchange of signals, while keeping the scheduling model separated from the energy-cost optimization model. Such integration means that the pre-existent schedulers and energy optimizers could be easily modified and reused without re-implementing the whole new system.

    Two industrial problems with different scheduling approaches are studied. The first problem is about pulp and paper production which uses the Resource Task Network (RTN) scheduling approach. The second one is about stainless steel production which is based on a bi-level heuristic implementation of an improved energy-aware scheduler. This work presents the decomposition methods that are available in literature and their application to the two industrial problems. Besides an improvement in the RTN approach for handling storages, this thesis describes a prototype implementation of the energy-aware RTN scheduler for paper and pulp production. Furthermore, this work investigates the performance of the application of different decomposition methods on different problem instances.

    The numerical case studies show that even though the decomposition decreases the solution quality compared to the monolithic system, it still gives good solutions within an acceptable duration with the advantage of having two separate pre-existent systems which are simply exchanging signals.

  • 2983. Aitken, Candice L.
    et al.
    Gorniak, Richard J. T.
    New York University.
    Kramer, Elissa L.
    New York University.
    Noz, Marilyn E.
    New York University.
    Farrell, Eward J.
    IBM Research.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Reddy, David P.
    Comparison of three methods used for fusion of SPECT-CT images of liver matastases1998In: Fusion98, International Conference on Multisource-Mulltisensor Information Fusion / [ed] Hamid R. Arabnia and Dongping (Daniel) Zhu, CSREA Press , 1998, p. 435-442Conference paper (Refereed)
    Abstract [en]

    We compare three methods for fusing SPECT-CT images: ImageMatch - an automatic three-dimensional/two-dimensional method developed by Focus Imaging; IBM Visualization Data Explorer - a three-diemensional interactive method developed by Internation Business Machines, Inc.; and qsh - an interactive three-dimensional/two-dimensional method developed at New York University. While many fusion methods have proved successful for registering brain images, most methods have been less successful for thoracic and abdominal images. We use images of liver metastases obtained with a radiolabeled breast tumor-directed antibody to illustrate the strengths and weakness of the methods reviewed. The images used are typical clinical images from eigth patients. We conclude that an optimal image fusion program should combine the strengths of each of the methods reviewed.

  • 2984. Aitken, Candice L.
    et al.
    Mahmoud, Faaiza
    McGuinness, Georgeann
    Kramer, Elissa L.
    Maguire, Gerald Q. Jr.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Noz, Marilyn E.
    New York University.
    Tumor localization and image registration of F-18FDG coincidence detection scans with computed tomographic scans2002In: Clinical Nuclear Medicine, ISSN 0363-9762, E-ISSN 1536-0229, Vol. 27, no 4, p. 275-282Article in journal (Refereed)
    Abstract [en]

    Purpose: The aim of this study was to determine the feasibility of registering routine clinical F-18 fluorodeoxyglucose (FDG) coincidence detection (CD) scans with computed tomographic (CT) scans for radiation treatment planning and case management. Methods: F-18 FDG CD and chest CT scans, performed in 10 randomly selected patients with confirmed or possible adenocarcinoma of the lung, were evaluated. The quality of the matches was verified by comparisons of the center-to-center distance between a region of interest (ROI) manually drawn on the CT slice and warped onto the CD slice with an ROI drawn manually directly on the CD slice. In addition, the overlap between the two ROIs was calculated. Results: All 10 F-18 FDG CD and CT scans were registered with good superimposition of soft tissue density on increased radionuclide activity. The center-to-center distance between the ROIs ranged from 0.29 mm to 8.08 mm, with an average center-to-center distance of 3.89 mm 2.42 mm (0.69 pixels +/- 0.34 pixels). The ROI overlap ranged from 77% to 99%, with an average of 90% +/- 5.6%. Conclusions: Although the use of F-18 FDG CD shows great promise for the identification of tumors, it shares the same drawbacks as those associated with radiolabeled monoclonal antibody SPECT and ligand-based positron emission tomographic scans in that anatomic markers are limited. This study shows that image registration is feasible and may improve the clinical relevance of CD images.

  • 2985.
    Aitken, Candice L.
    et al.
    New York University.
    McGuinness, Georgeann
    New York University.
    Siddiqui, Faaiza
    New York University.
    Ton, Anthony
    New York University.
    Kramer, Elissa L
    New York University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Tumor localization and image registration of 18-FDG SPECT scans with CT scans1999In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 40, no 5, p. 290P-291PArticle in journal (Refereed)
    Abstract [en]

    PURPOSE:

    The aim of this study was to determine the feasibility of registering routine clinical F-18 fluorodeoxyglucose (FDG) coincidence detection (CD) scans with computed tomographic (CT) scans for radiation treatment planning and case management.

    METHODS:

    F-18 FDG CD and chest CT scans, performed in 10 randomly selected patients with confirmed or possible adenocarcinoma of the lung, were evaluated. The quality of the matches was verified by comparisons of the center-to-center distance between a region of interest (ROI) manually drawn on the CT slice and warped onto the CD slice with an ROI drawn manually directly on the CD slice. In addition, the overlap between the two ROIs was calculated.

    RESULTS:

    All 10 F-18 FDG CD and CT scans were registered with good superimposition of soft tissue density on increased radionuclide activity. The center-to-center distance between the ROIs ranged from 0.29 mm to 8.08 mm, with an average center-to-center distance of 3.89 mm +/- 2.42 mm (0.69 pixels +/- 0.34 pixels). The ROI overlap ranged from 77% to 99%, with an average of 90% +/- 5.6%.

    CONCLUSIONS:

    Although the use of F-18 FDG CD shows great promise for the identification of tumors, it shares the same drawbacks as those associated with radiolabeled monoclonal antibody SPECT and ligand-based positron emission tomographic scans in that anatomic markers are limited. This study shows that image registration is feasible and may improve the clinical relevance of CD images.

  • 2986.
    Ait-Lakbir, Hanane
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Study and Industrialization of Computational Methods for Orbital Maneuvers2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of electric propulsion is a watershed in the space field. Indeed, due to its eÿciency in term of mass consumption, the actors of the space industries see in this piece of technology a means to manufacture lighter satellites and to launch them at lower cost. To face with this new market, industries need to develop new tools to handle these satellites and their missions. This report will elaborate on the methods used to compute maneuvers for all-electric spacecraft.

    One of the main phases during satellite operations is maneuvering to ensure on the one hand a correct configuration to achieve the mission and on the other hand the integrity of the satellite. The present work is focused on the computation of the orbital maneuvers during the early phase of the mission: orbit raising. Due to the characteristics of electric propulsion, an overall approach provided by the application of the optimal control theory is required to compute these maneuvers performed by low-thrust engines. This report will develop the use of an indirect method based on the Pontryagin minimum principle. Two types of problems related to the constraints during the space missions are presented. Because electric maneuvers are longer than chemical maneuvers, it is usually necessary to seek to minimize the duration of a maneuver. The second interesting performance is the remaining propellant mass to achieve the mission: therefore, the minimization of the mass consumption during the maneuver is the second performance considered in the report.

    During the internship, a JAVA implementation of the resolution of these two problems has been done. The report will present the preliminary results as well as the encountered difficulties and some possible solutions.

  • 2987.
    Aittokoski, Timo
    et al.
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Miettinen, Kaisa
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Cost Effective Simulation-Based Multiobjective Optimization in Performance of Internal Combustion Engine2008In: Engineering optimization (Print), ISSN 0305-215X, E-ISSN 1029-0273, Vol. 40, no 7, p. 593-612Article in journal (Refereed)
    Abstract [en]

    Solving real-life engineering problems requires often multiobjective, global, and efficient (in terms of objective function evaluations) treatment. In this study, we consider problems of this type by discussing some drawbacks of the current methods and then introduce a new population-based multiobjective optimization algorithm UPS-EMOA which produces a dense (not limited to the population size) approximation of the Pareto-optimal set in a computationally effective manner.

  • 2988.
    Aittokoski, Timo
    et al.
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Miettinen, Kaisa
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Decreasing Computational Cost of Simulation Based Interactive Multiobjective Optimization with Adustable Solution Accuracy2008Report (Other academic)
  • 2989.
    Aittokoski, Timo
    et al.
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Miettinen, Kaisa
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Efficient Evolutionary Method to Approximate the Pareto Optimal Set in Multiobjective Optimization2008In: Proceedings of the International Conference on Engineering Optimization EngOpt 2008, 2008Conference paper (Other academic)
    Abstract [en]

    Solving real-life engineering problems requires often multiobjective, global and efficient (in terms of ob-jective function evaluations) treatment. In this study, we consider problems of this type by discussingsome drawbacks of the current methods and then introduce a new population based multiobjective op-timization algorithm which produces a dense (not limited to the population size) approximation of thePareto optimal set in a computationally effective manner.

  • 2990.
    Aittokoski, Timo
    et al.
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Äyrämö, Sami
    Department of Mathematical Information Technology, University of Jyväskylä, Finland.
    Miettinen, Kaisa
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Clustering aided approach for decision making in computationally expensive multiobjective optimization2009In: Optimization Methods and Software, ISSN 1055-6788, E-ISSN 1029-4937, Vol. 24, no 2, p. 157-174Article in journal (Refereed)
    Abstract [en]

    Typically, industrial optimization problems need to be solved in an efficient, multiobjective and global manner, because they are often computationally expensive (as function values are typically based on simulations), they may contain multiple conflicting objectives, and they may have several local optima. Solving such problems may be challenging and time consuming when the aim is to find the most preferred Pareto optimal solution.

    In this study, we propose a method where we use an advanced clustering technique to reveal essential characteristics of the approximation of the Pareto optimal set, which has been generated beforehand. Thus, the decision maker (DM) is involved only after the most time consuming computation is finished. After the initiation phase, a moderate number of cluster prototypes projected to the Pareto optimal set is presented to the DM to be studied. This allows him/her to rapidly gain an overall understanding of the main characteristics of the problem without placing too much cognitive load on the DM. Furthermore, we also suggest some ways of applying our approach to different types of problems and demonstrate it with an example related to internal combustion engine design.

  • 2991. Ai-Xi, Chen
    et al.
    Hong, Wang
    Duan, Sai
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Hai-Ming, Zhang
    Xin, Xu
    Li-Feng, Chi
    Potential-Induced Phase Transition of N-Isobutyryl-L-cysteine Monolayers on Au(111) Surfaces2017In: Wuli huaxue xuebao, ISSN 1000-6818, Vol. 33, no 5, p. 1010-1016Article in journal (Refereed)
    Abstract [en]

    Functional solid substrates modified by self-assembled monolayers (SAMs) have potential applications in biosensors, chromatography, and biocompatible materials. The potential-induced phase transition of N-isobutyryl-L-cysteine (L-NIBC) SAMs on Au(111) surfaces was investigated by in-situ electrochemical scanning tunneling microscopy (EC-STM) in 0.1 mol.L-1 H2SO4 solution. The NIBC SAMs with two distinct structures (alpha phase and beta phase) can be prepared by immersing the Au(111) substrate in pure NIBC aqueous solution and NIBC solution controlled by phosphate buffer at pH 7, respectively. The as-prepared a phase and beta phase of NIBC SAMs show various structural changes under the control of electrochemical potentials of the Au(111) in H2SO4 solution. The a phase NIBC SAMs exhibit structural changes from ordered to disordered structures with potential changes from 0.7 V (vs saturated calomel electrode, SCE) to 0.2 V. However, the beta phase NIBC SAMs undergo structural changes from disordered structures (E < 0.3 V) to y phase (0.4 V < E < 0.5 V) and finally to the beta phase (0.5 V < E < 0.7 V). EC-STM images also indicate that the phase transition from the alpha phase NIBC SAMs to the a phase occurs at positive potential. Combined with density functional theory (DFT) calculations, the phase transition from the beta phase to the a phase is explained by the potential-induced break of bonding interactions between -COO- and the negatively charged gold surfaces.

  • 2992. Aizman, O
    et al.
    Brismar, Hjalmar
    Uhlen, P
    Zettergren, E
    Levey, A I
    Forssberg, H
    Greengard, P
    Aperia, A
    Anatomical and physiological evidence for D-1 and D-2 dopamine receptor colocalization in neostriatal neurons2000In: Nature Neuroscience, ISSN 1097-6256, E-ISSN 1546-1726, Vol. 3, no 3, p. 226-230Article in journal (Refereed)
    Abstract [en]

    Despite the importance of dopamine signaling, it remains unknown if the two major subclasses of dopamine receptors exist on the same or distinct populations of neurons. Here we used confocal microscopy to demonstrate that virtually all striatal neurons, both in vitro and in vivo, contained dopamine receptors of both classes. We also provide functional evidence for such colocalization: in essentially all neurons examined, fenoldopam, an agonist of the D-1 subclass of receptors, inhibited both the Na+/K+ pump and tetrodotoxin (TTX)-sensitive sodium channels, and quinpirole, an agonist of the Dr subclass of receptors, activated TTX-sensitive sodium channels. Thus D-1 and D-2 classes of ligands may functionally interact in virtually all dopamine-responsive neurons within the basal ganglia.

  • 2993. Aizman, O.
    et al.
    Uhlen, P.
    Lal, M.
    Brismar, Hjalmar
    Aperia, A.
    Ouabain, a steroid hormone that signals with slow calcium oscillations2001In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 98, no 23, p. 13420-13424Article in journal (Refereed)
    Abstract [en]

    The plant-derived steroid, digoxin, a specific inhibitor of Na,K-ATPase, has been used for centuries in the treatment of heart disease. Recent studies demonstrate the presence of a digoxin analog, ouabain, in mammalian tissue, but its biological role has not been elucidated. Here, we show in renal epithelial cells that ouabain, in doses causing only partial Na,K-ATPase inhibition, acts as a biological inducer of regular, low-frequency intracellular calcium ([Ca2+](i)) oscillations that elicit activation of the transcription factor, NF-KB. Partial inhibition of Na,K-ATPase using low extracellular K+ and depolarization of cells did not have these effects. Incubation of cells in Ca2+-free media, inhibition of voltage-gated calcium channels, inositol triphosphate receptor antagonism, and redistribution of actin to a thick layer adjacent to the plasma membrane abolished [Ca2+](i) oscillations, indicating that they were caused by a concerted action of inositol triphosphate receptors and capacitative calcium entry via plasma membrane channels. Blockade of ouabain-induced [C-a2+](i) oscillations prevented activation of NF-kappaB. The results demonstrate a new mechanism for steroid signaling via plasma membrane receptors and underline a novel role for the steroid hormone, ouabain, as a physiological inducer of [Ca2+](i) oscillations involved in transcriptional regulation in mammalian cells.

  • 2994. Ajalloueian, Fatemeh
    et al.
    Zeiai, Said
    Rojas, Ramiro
    Department of Chemistry, Division of Polymer Chemistry, Uppsala University, Sweden.
    Fossum, Magdalena
    Hilborn, Jöns
    One-Stage Tissue Engineering of Bladder Wall Patches for an Easy-To-Use Approach at the Surgical Table2013In: Tissue Engineering. Part C, Methods, ISSN 1937-3384, E-ISSN 1937-3392, Vol. 19, no 9, p. 688-696Article in journal (Refereed)
    Abstract [en]

    We present a method for producing a cell-scaffold hybrid construct at the bedside. The construct is composed of plastic-compressed collagen together with a poly(e-caprolactone) (PCL)-knitted mesh that yields an integrated, natural-synthetic scaffold. This construct was evaluated by seeding of minced bladder mucosa, followed by proliferation in vitro. High mechanical strength in combination with a biological environment suitable for tissue growth was achieved through the creation of a hybrid construct that showed an increased tensile strength (17.9 +/- 2.6 MPa) when compared to plastic-compressed collagen (0.6 +/- 0.12 MPa). Intimate contact between the collagen and the PCL fabric was required to ensure integrity without delamination of the construct. This contact was achieved by surface alkaline hydrolysis of the PCL, followed by adsorption of poly(vinyl) alcohol. The improvement in hydrophilicity of the PCL-knitted mesh was confirmed through water contact angle measurements, and penetration of the collagen into the mesh was evaluated by scanning electron microscopy (SEM). Particles of minced bladder mucosa tissue were seeded onto this scaffold, and the proliferation was followed for 6 weeks in vitro. Results obtained from phase contrast microscopy, SEM, and histological staining indicated that cells migrated from the minced tissue particles and reorganized on the scaffold. Cells were viable and proliferative, with morphological features characteristic of urothelial cells. Proliferation reached the point at which a multilayer with a resemblance to stratified urothelium was achieved. This successful method could potentially be used for in vivo applications in reconstructive urology as an engineered autologous tissue transplant without the requirement for in vitro culture before transplantation.

  • 2995.
    Ajami Gale Rashidi, Sam André
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID.
    Designing for sustainable grocery shopping: A conceptual design to encourage sustainable shopping2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Climate change is one of the biggest issues that the world faces today, and one of the biggest contributors to climate change are groceries. This paper aims at using digital artefacts to create a product or design that will encourage the user to shop more environmentally friendly. To achieve this, I have tried to identify the major hindrances today that grocery shoppers are faced with through the user centered method Contextual Inquiry.  I have then presented the results from the inquiry to students at KTH Royal Institute of Technology during workshops. During these workshops, the students have conceptualized ideas and designs for different solutions. Based on their results, I have created a prototype design that I call the SmartCart. This cart consists of a regular shopping cart with a screen similar to an iPad attached to the handlebars. This screen then delivers easily apprehensible information about different grocery products environmental impact in real time. The design has not been tested in a live environment, but initial testing indicates that a live application could give satisfying results in lowering the sales of grocery products with a high environmental impact, while the design also could simultaneously improve the shopping experience for the customers in the grocery store.

  • 2996.
    Ajami, Sam
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Maupin, Lucas
    KTH, School of Computer Science and Communication (CSC).
    The effects of video gaming on university grades2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this 21st century IT-world, the use of video gaming has dramatically grown and taken a firm place in many young peoples’ busy day-to-day schedule. As a result, many are growing worried that video gaming will affect people in a negative way, especially when it comes to students’ academic performance.

     

    This thesis is an investigation of the correlation between games and university grades amongst students.

     

    Our results show that students, who played more, had more problems with their grades than the ones who played less. However, the results also show that gaming itself is not the problem, as the correlation between hours spent gaming and grades, is similar to the correlation between hours spent on other hobbies and grades. In essence, two hours of video gaming affects the grades just as much as two hours of physical exercise.

     

    The conclusion from our research is that it is the time spent on other activities than studying, that affects the grades. Video gaming is however amongst the easiest activities to be engaged in for an extended period of time, and can therefore be indirectly harmful to students’ grades.

  • 2997.
    Ajani, Altinay
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Karaömer, Ahmed
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Hur samlar Skanska in information vid kalkylering?2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today's industrialized society projects are considered as the obvious model for development. The first step in projects where information plays an essential role is in calculations. This is where the projects future is decided. Here it is important to be clear about the information compiled and making sure that the storage of the information is easily accessed for the project members. Without a proper flow of information, the organization will have difficulty adapting to changes and problems that arise. The purpose of this study is to investigate how the calculation is made in theory and in practice to get an understanding of how the flow of information plays its role.The theoretical framework was based on the theories that were found in a search among KTHB databases and Google Scholar. The information flow has been divided into three parts, presentation, transport and storage of information. Also studied are a number of different calculation methods. To obtain a complementary picture of how this is applied in practice, a case study has been conducted at Skanska Sverige AB. This study includes three interview occasions and continuous contact with a purchasing manager at Skanska. The calculation methods that were examined were ABC - calculation, product calculation and production calculation. Later examined were which of these calculation methods is used at Skanska Sweden AB. Calculations are made from the company's information management system and Skanska use a custom developed system, Spik. It was further examined which type of information that has the greatest impact on the modeling of the calculations and which factors that are crucial. The theory studies are compared with the empirical studies through discussion about the flow of informations role in the development of calculations at Skanska. Later discussed are the recommendations on how the information flow could be improved in the development of calculations.

  • 2998. Ajello, M.
    et al.
    Albert, A.
    Allafort, A.
    Baldini, L.
    Barbiellini, G.
    Bastieri, D.
    Bellazzini, R.
    Bissaldi, E.
    Bonamente, E.
    Brandt, T. J.
    Bregeon, J.
    Brigida, M.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Cecchi, C.
    Charles, E.
    Chekhtman, A.
    Chiang, J.
    Chiaro, G.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Cominsky, L. R.
    Conrad, J.
    Cutini, S.
    D'Ammando, F.
    de Palma, F.
    Dermer, C. D.
    Desiante, R.
    Digel, S. W.
    do Couto e Silva, E.
    Drell, P. S.
    Drlica-Wagner, A.
    Favuzzi, C.
    Focke, W. B.
    Franckowiak, A.
    Fukazawa, Y.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Germani, S.
    Giglietto, N.
    Giommi, P.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Godfrey, G.
    Grenier, I. A.
    Grove, J. E.
    Guiriec, S.
    Hadasch, D.
    Hayashida, M.
    Hays, E.
    Horan, D.
    Hou, X.
    Hughes, R. E.
    Inoue, Y.
    Jackson, Miranda S.
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Jogler, T.
    Johannesson, G.
    Johnson, A. S.
    Johnson, W. N.
    Kamae, T.
    Knoedlseder, J.
    Kocevski, D.
    Kuss, M.
    Lande, J.
    Larsson, S.
    Latronico, L.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Lubrano, P.
    Mayer, M.
    Mazziotta, M. N.
    McEnery, J. E.
    Michelson, P. F.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Murphy, R.
    Nakamori, T.
    Nemmen, R.
    Nuss, E.
    Ohno, M.
    Ohsugi, T.
    Omodei, N.
    Orienti, M.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Panetta, J. H.
    Perkins, J. S.
    Pesce-Rollins, M.
    Petrosian, V.
    Piron, F.
    Pivato, G.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzano, M.
    Reimer, A.
    Reimer, O.
    Roth, M.
    Schulz, A.
    Sgro, C.
    Siskind, E. J.
    Spandre, G.
    Spinelli, P.
    Takahashi, H.
    Thayer, J. G.
    Thayer, J. B.
    Thompson, D. J.
    Tibaldo, L.
    Tinivella, M.
    Tosti, G.
    Troja, E.
    Usher, T. L.
    Vandenbroucke, J.
    Vasileiou, V.
    Vianello, G.
    Vitale, V.
    Werner, M.
    Winer, B. L.
    Wood, D. L.
    Wood, K. S.
    Yang, Z.
    Impulsive and long duration high-energy gamma-ray emission from the very bright 2012 march 7 solar flares2014In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 789, no 1, p. 20-Article in journal (Refereed)
    Abstract [en]

    The Fermi Large Area Telescope (LAT) detected gamma-rays up to 4 GeV from two bright X-class solar flares on 2012 March 7, showing both an impulsive and temporally extended emission phases. The gamma-rays appear to originate from the same active region as the X-rays associated with these flares. The >100 MeV gamma-ray flux decreases monotonically during the first hour (impulsive phase) followed by a slower decrease for the next 20 hr. A power law with a high-energy exponential cutoff can adequately describe the photon spectrum. Assuming that the gamma rays result from the decay of pions produced by accelerated protons and ions with a power-law spectrum, we find that the index of that spectrum is similar to 3, with minor variations during the impulsive phase. During the extended phase the photon spectrum softens monotonically, requiring the proton index varying from similar to 4 to >5. The >30 MeV proton flux observed by the GOES satellites also shows a flux decrease and spectral softening, but with a harder spectrum (index similar to 2-3). Based on these observations, we explore the relative merits of prompt or continuous acceleration scenarios, hadronic or leptonic emission processes, and acceleration at the solar corona or by the fast coronal mass ejections. We conclude that the most likely scenario is continuous acceleration of protons in the solar corona that penetrate the lower solar atmosphere and produce pions that decay into gamma rays. However, acceleration in the downstream of the shock cannot be definitely ruled out.

  • 2999. Ajello, M.
    et al.
    Albert, A.
    Atwood, W. B.
    Barbiellini, G.
    Bastieri, D.
    Bechtol, K.
    Bellazzini, R.
    Bissaldi, E.
    Blandford, R. D.
    Bloom, E. D.
    Bonino, R.
    Bottacini, E.
    Brandt, T. J.
    Bregeon, J.
    Bruel, P.
    Buehler, R.
    Buson, S.
    Caliandro, G. A.
    Cameron, R. A.
    Caputo, R.
    Caragiulo, M.
    Carave, P. A.
    Cecchi, C.
    Chekhtman, A.
    Chiang, J.
    Chiaro, G.
    Ciprini, S.
    Cohen-Tanugi, J.
    Cominsky, L. R.
    Conrad, J.
    Cutini, S.
    D'Ammando, F.
    de Angelis, A.
    de Palma, F.
    Desiante, R.
    Di Venere, L.
    Drell, P. S.
    Favuzzi, C.
    Ferrara, E. C.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Giglietto, N.
    Giommi, P.
    Giordano, F.
    Giroletti, M.
    Glanzman, T.
    Godfrey, G.
    Gomez-Vargas, G. A.
    Grenier, I. A.
    Guiriec, S.
    Gustafsson, M.
    Harding, A. K.
    Hewitt, J. W.
    Hill, A. B.
    Horan, D.
    Jogler, T.
    Johannesson, G.
    Johnson, A. S.
    Kamae, T.
    Karwin, C.
    Knoedlseder, J.
    Kuss, M.
    Larsson, Stefan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Latronico, L.
    Li, J.
    Li, L.
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Longo, F.
    Loparco, F.
    Lovellette, M. N.
    Lubrano, P.
    Magill, J.
    Maldera, S.
    Malyshev, D.
    Manfreda, A.
    Mayer, M.
    Mazziotta, M. N.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nuss, E.
    Ohno, M.
    Ohsugi, T.
    Omodei, N.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Pesce-Rollins, M.
    Piron, F.
    Pivato, G.
    Porter, T. A.
    Raino, S.
    Rando, R.
    Razzano, M.
    Reimer, A.
    Reimer, O.
    Ritz, S.
    Sanchez-Conde, M.
    Parkinson, P. M. Saz
    Sgro, C.
    Siskind, E. J.
    Smith, D. A.
    Spada, F.
    Spandre, G.
    Spinelli, P.
    Suson, D. J.
    Tajima, H.
    Takahashi, H.
    Thayer, J. B.
    Torres, D. F.
    Tosti, G.
    Troja, E.
    Uchiyama, Y.
    Vianello, G.
    Winer, B. L.
    Wood, K. S.
    Zaharijas, G.
    Zimmer, S.
    FERMI-LAT OBSERVATIONS OF HIGH-ENERGY gamma-RAY EMISSION TOWARD THE GALACTIC CENTER2016In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 819, no 1, article id 44Article in journal (Refereed)
    Abstract [en]

    The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of the emission toward the Galactic center (GC) in high-energy gamma-rays. This paper describes the analysis of data taken during the first 62 months of the mission in the energy range 1-100 GeV from a 15 degrees x 15 degrees region about the direction of the GC. Specialized interstellar emission models (IEMs) are constructed to enable the separation of the.-ray emissions produced by cosmic ray particles interacting with the interstellar gas and radiation fields in the Milky Way into that from the inner similar to 1 kpc surrounding the GC, and that from the rest of the Galaxy. A catalog of point sources for the 15 degrees x 15 degrees region is self-consistently constructed using these IEMs: the First Fermi-LAT Inner Galaxy Point Source Catalog (1FIG). The spatial locations, fluxes, and spectral properties of the 1FIG sources are presented, and compared with gamma-ray point sources over the same region taken from existing catalogs. After subtracting the interstellar emission and point-source contributions a residual is found. If templates that peak toward the GC are used to model the positive residual the agreement with the data improves, but none of the additional templates tried account for all of its spatial structure. The spectrum of the positive residual modeled with these templates has a strong dependence on the choice of IEM.

  • 3000.
    Ajello, M.
    et al.
    Clemson Univ, Dept Phys & Astron, Kinard Lab Phys, Clemson, SC 29634 USA..
    Allafort, A.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA.;Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy.;Univ Torino, Dipartimento Fis, I-10125 Turin, Italy.;Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA..
    Axelsson, Magnus
    KTH, School of Engineering Sciences (SCI), Physics. Tokyo Metropolitan Univ, Dept Phys, Minami Osawa 1-1, Hachioji, Tokyo 1920397, Japan..
    Baldini, L.
    Univ Pisa, I-56127 Pisa, Italy.;Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Barbiellini, G.
    Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy.;Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy..
    Baring, M. G.
    Rice Univ, Dept Phys & Astron, MS 108,POB 1892, Houston, TX 77251 USA..
    Bastieri, D.
    Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy.;Univ Padua, Dipartimento Fis Astron G Galilei, I-35131 Padua, Italy..
    Bellazzini, R.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Berenji, B.
    Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90032 USA..
    Bissaldi, E.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Blandford, R. D.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Bloom, E. D.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Bonino, R.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy.;Univ Torino, Dipartimento Fis, I-10125 Turin, Italy..
    Bottacini, E.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Brandt, T. J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Bregeon, J.
    Univ Montpellier, Lab Univers & Particules Montpellier, CNRS IN2P3, F-34095 Montpellier, France..
    Bruel, P.
    CNRS IN2P3, Lab Leprince Ringuet, Ecole Polytech, F-91128 Palaiseau, France..
    Buehler, R.
    Deutsch Elektronen Synchrotron DESY, D-15738 Zeuthen, Germany..
    Burnett, T. H.
    Univ Washington, Dept Phys, Seattle, WA 98195 USA..
    Buson, S.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Cameron, R. A.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Caputo, R.
    CRESST, Greenbelt, MD 20771 USA.;NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Caraveo, P. A.
    INAF, Ist Astrofis Spaziale & Fis Cosm Milano, Via E Bassini 15, I-20133 Milan, Italy..
    Casandjian, J. M.
    Univ Paris Diderot, Laboratoire AIM, CEA IRFU, CNRS,Serv Astrophys,CEA Saclay, F-91191 Gif Sur Yvette, France..
    Cavazzuti, E.
    Italian Space Agcy, Via Politecn Snc, I-00133 Rome, Italy..
    Chekhtman, A.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy.;George Mason Univ, Coll Sci, Fairfax, VA 22030 USA.;Naval Res Lab, Washington, DC 20375 USA..
    Cheung, C. C.
    Naval Res Lab, Space Sci Div, Washington, DC 20375 USA..
    Chiang, J.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Chiaro, G.
    INAF, Ist Astrofis Spaziale & Fis Cosm Milano, Via E Bassini 15, I-20133 Milan, Italy..
    Ciprini, S.
    Space Sci Data Ctr Agenzia Spaziale Italiana, Via Politecnico,Snc, I-00133 Rome, Italy.;Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy..
    Cohen-Tanugi, J.
    Univ Montpellier, Lab Univers & Particules Montpellier, CNRS IN2P3, F-34095 Montpellier, France..
    Cominsky, L. R.
    Sonoma State Univ, Dept Phys & Astron, Rohnert Pk, CA 94928 USA..
    Costantin, D.
    Univ Padua, Dipartimento Fis Astron G Galilei, I-35131 Padua, Italy..
    Cuoco, A.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy.;Rhein Westfal TH Aachen, Inst Theoret Particle Phys & Cosmol TTK, D-52056 Aachen, Germany..
    Cutini, S.
    Space Sci Data Ctr Agenzia Spaziale Italiana, Via Politecnico,Snc, I-00133 Rome, Italy.;Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy..
    D'Ammando, F.
    INAF, Ist Radioastron, I-40129 Bologna, Italy.;Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy..
    de Palma, F.
    Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy.;Univ Telemat Pegaso, Piazza Trieste & Trento,48, I-80132 Naples, Italy..
    Di Lalla, N.
    Univ Pisa, I-56127 Pisa, Italy.;Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Di Mauro, M.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Di Venere, L.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Dubois, R.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Dumora, D.
    Univ Bordeaux 1, Ctr Etud Nucl Bordeaux Gradignan, IN2P3 CNRS, BP120, F-33175 Gradignan, France..
    Favuzzi, C.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Ferrara, E. C.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Franckowiak, A.
    Deutsch Elektronen Synchrotron DESY, D-15738 Zeuthen, Germany..
    Fukazawa, Y.
    Hiroshima Univ, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan..
    Funk, S.
    Friedrich Alexander Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, Erwin Rommel Str 1, D-91058 Erlangen, Germany..
    Fusco, P.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Gargano, F.
    Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Gasparrini, D.
    Space Sci Data Ctr Agenzia Spaziale Italiana, Via Politecnico,Snc, I-00133 Rome, Italy.;Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy..
    Giglietto, N.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Gill, R.
    Open Univ Israel, Dept Nat Sci, 1 Univ Rd,POB 808, IL-43537 Raanana, Israel..
    Giordano, F.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Giroletti, M.
    INAF, Ist Radioastron, I-40129 Bologna, Italy..
    Glanzman, T.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Granot, J.
    Open Univ Israel, Dept Nat Sci, 1 Univ Rd,POB 808, IL-43537 Raanana, Israel..
    Green, D.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;Univ Maryland, Dept Phys, College Pk, MD 20742 USA.;Univ Maryland, Dept Astron, College Pk, MD 20742 USA..
    Grenier, I. A.
    Univ Paris Diderot, Laboratoire AIM, CEA IRFU, CNRS,Serv Astrophys,CEA Saclay, F-91191 Gif Sur Yvette, France..
    Grondin, M. -H
    Guillemot, L.
    Univ Orleans, Lab Phys & Chim Environm & Espace, CNRS, F-45071 Orleans 02, France.;CNRS INSU, Stn Radioastron Nancay, Observ Paris, F-18330 Nancay, France..
    Guiriec, S.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;George Washington Univ, Dept Phys, 725 21st St NW, Washington, DC 20052 USA..
    Harding, A. K.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Hays, E.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Horan, D.
    CNRS IN2P3, Lab Leprince Ringuet, Ecole Polytech, F-91128 Palaiseau, France..
    Imazato, F.
    Hiroshima Univ, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan..
    Johannesson, G.
    Univ Iceland, Sci Inst, IS-107 Reykjavik, Iceland.;NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Kamae, T.
    Univ Tokyo, Dept Phys, Grad Sch Sci, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan..
    Kensei, S.
    Hiroshima Univ, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan..
    Kocevski, D.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy.;NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Kuss, M.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    La Mura, G.
    Univ Padua, Dipartimento Fis Astron G Galilei, I-35131 Padua, Italy..
    Larsson, S.
    KTH, School of Engineering Sciences (SCI), Physics.
    Latronico, L.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy..
    Li, J.
    Inst Space Sci CSICIEEC, Campus UAB,Carrer Magrans S-N, E-08193 Barcelona, Spain..
    Longo, F.
    Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy.;Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy..
    Loparco, F.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Lovellette, M. N.
    Naval Res Lab, Space Sci Div, Washington, DC 20375 USA..
    Lubrano, P.
    Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy..
    Magill, J. D.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA.;Univ Maryland, Dept Astron, College Pk, MD 20742 USA..
    Maldera, S.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy..
    Manfreda, A.
    Univ Pisa, I-56127 Pisa, Italy.;Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Mazziotta, M. N.
    Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Michelson, P. F.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Mizuno, T.
    Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Higashihiroshima, Hiroshima 7398526, Japan..
    Moiseev, A. A.
    CRESST, Greenbelt, MD 20771 USA.;NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;Univ Maryland, Dept Phys, College Pk, MD 20742 USA.;Univ Maryland, Dept Astron, College Pk, MD 20742 USA..
    Monzani, M. E.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Moretti, E.
    Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany..
    Morselli, A.
    Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy..
    Moskalenko, I. V.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Negro, M.
    Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy.;Univ Torino, Dipartimento Fis, I-10125 Turin, Italy..
    Nuss, E.
    Univ Montpellier, Lab Univers & Particules Montpellier, CNRS IN2P3, F-34095 Montpellier, France..
    Ojha, R.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Omodei, N.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Orlando, E.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Ormes, J. F.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA..
    Palatiello, M.
    Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy.;Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy..
    Paliya, V. S.
    Clemson Univ, Dept Phys & Astron, Kinard Lab Phys, Clemson, SC 29634 USA..
    Paneque, D.
    Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany..
    Persic, M.
    Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy.;Ist Nazl Astrofis, Osservatorio Astron Trieste, I-34143 Trieste, Italy..
    Pesce-Rollins, M.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Petrosian, V.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Piron, F.
    Univ Montpellier, Lab Univers & Particules Montpellier, CNRS IN2P3, F-34095 Montpellier, France..
    Porter, T. A.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Principe, G.
    Friedrich Alexander Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, Erwin Rommel Str 1, D-91058 Erlangen, Germany..
    Racusin, J. L.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Raino, S.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Rando, R.
    Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy.;Univ Padua, Dipartimento Fis Astron G Galilei, I-35131 Padua, Italy..
    Razzano, M.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Razzaque, S.
    Univ Johannesburg, Dept Phys, POB 524, ZA-2006 Auckland Pk, South Africa..
    Reimer, A.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA.;Leopold Franzens Univ Innsbruck, Inst Astro & Teilchenphys, A-6020 Innsbruck, Austria.;Leopold Franzens Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria..
    Reimer, O.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA.;Leopold Franzens Univ Innsbruck, Inst Astro & Teilchenphys, A-6020 Innsbruck, Austria.;Leopold Franzens Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria..
    Ritz, S.
    Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Dept Phys, Santa Cruz, CA 95064 USA.;Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA..
    Rochester, L. S.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Ryde, Felix
    KTH, School of Engineering Sciences (SCI), Physics.
    Parkinson, P. M. Saz
    Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Dept Phys, Santa Cruz, CA 95064 USA.;Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA.;Univ Hong Kong, Dept Phys, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China.;Univ Hong Kong, Lab Space Res, Hong Kong, Hong Kong, Peoples R China..
    Sgro, C.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Siskind, E. J.
    NYCB Real Time Comp Inc, Lattingtown, NY 11560 USA..
    Spada, F.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Spandre, G.
    Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy..
    Spinelli, P.
    M Merlin Universita, Dipartimento Fis, I-70126 Bari, Italy.;Politecn Bari, I-70126 Bari, Italy.;Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy..
    Suson, D. J.
    Purdue Univ Northwset, Hammond, IN 46323 USA..
    Tajima, H.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA.;Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi 4648601, Japan..
    Takahashi, M.
    Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany..
    Tak, D.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;Univ Maryland, Dept Phys, College Pk, MD 20742 USA.;Univ Maryland, Dept Astron, College Pk, MD 20742 USA..
    Thayer, J. G.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Thayer, J. B.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Torres, D. F.
    Inst Space Sci CSICIEEC, Campus UAB,Carrer Magrans S-N, E-08193 Barcelona, Spain.;ICREA, E-08010 Barcelona, Spain..
    Torresi, E.
    INAF, Ist Astrofis Spaziale & Fis Cosm Bologna, Via P Gobetti 101, I-40129 Bologna, Italy..
    Tosti, G.
    Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy.;Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy..
    Troja, E.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;Univ Maryland, Dept Phys, College Pk, MD 20742 USA.;Univ Maryland, Dept Astron, College Pk, MD 20742 USA..
    Valverde, J.
    CNRS IN2P3, Lab Leprince Ringuet, Ecole Polytech, F-91128 Palaiseau, France..
    Venters, T. M.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Vianello, G.
    Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Dept Phys, Stanford, CA 94305 USA.;Stanford Univ, SLAC Natl Accelerator Lab, Stanford, CA 94305 USA..
    Wood, K.
    Naval Res Lab, Washington, DC 20375 USA.;Praxis Inc, Alexandria, VA 22303 USA..
    Yang, C.
    Hiroshima Univ, Dept Phys Sci, Higashihiroshima, Hiroshima 7398526, Japan..
    Zaharijas, G.
    Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy.;Univ Trieste, I-34127 Trieste, Italy.;Univ Nova Gor, Ctr Astrophys & Cosmol, Nova Gorica, Slovenia..
    Fermi-LAT Observations of LIGO/Virgo Event GW1708172018In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 861, no 2, article id 88Article in journal (Refereed)
    Abstract [en]

    We present the Fermi Large Area Telescope (LAT) observations of the binary neutron star merger event GW170817 and the associated short gamma-ray burst (SGRB) GRB 170817A detected by the Fermi Gamma-ray Burst Monitor. The LAT was entering the South Atlantic Anomaly at the time of the LIGO/Virgo trigger (t(GW)) and therefore cannot place constraints on the existence of high-energy (E > 100 MeV) emission associated with the moment of binary coalescence. We focus instead on constraining high-energy emission on longer timescales. No candidate electromagnetic counterpart was detected by the LAT on timescales of minutes, hours, or days after the LIGO/Virgo detection. The resulting flux upper bound (at 95% C. L.) from the LAT is 4.5. x. 10(-10) erg cm(-2) s(-1) in the 0.1-1 GeV range covering a period from tGW. +. 1153 s to t(GW). +. 2027 s. At the distance of GRB 170817A, this flux upper bound corresponds to a luminosity upper bound of 9.7. x. 10(43) erg s(-1), which is five orders of magnitude less luminous than the only other LAT SGRB with known redshift, GRB 090510. We also discuss the prospects for LAT detection of electromagnetic counterparts to future gravitational-wave events from Advanced LIGO/Virgo in the context of GW170817/GRB 170817A.

57585960616263 2951 - 3000 of 124280
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