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  • 2351. Aguirre, Miren
    et al.
    Johansson Salazar-Sandoval, Eric
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. SP Technical Research Institute of Sweden, Sweden.
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Ahniyaz, Anwar
    Paulis, Maria
    Ramon Leiza, Jose
    Hybrid acrylic/CeO2 nanocomposites using hydrophilic, spherical and high aspect ratio CeO2 nanoparticles2014In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, no 47, p. 20280-20287Article in journal (Refereed)
    Abstract [en]

    A dispersion of CeO2 nanoparticles and nanorods stabilized with nitrilotriacetic acid (NTA) and a 4,4'-azobis(4-cyanovaleric acid) (V-501) initiator has been used to initiate the emulsion polymerization of acrylic monomers, yielding stable hybrid CeO2 nanoparticle-nanorod/polyacrylate latexes for the first time. Films cast from these hybrid latexes are transparent due to the very homogenous distribution of the polymer compatibilized CeO2. Furthermore, it has been proven that the UV-Vis absorption capacity of the hybrid latexes is enhanced with the incorporation of the nanorods.

  • 2352.
    Aguirre Quiroz, Gerardo Daniel
    KTH, School of Information and Communication Technology (ICT).
    Evaluation of the potential benefits of using Licensed Shared Access in the Americas2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Internet has become an ubiquitous service and human need. Mobile networks have been struggling with the "Mobile Data Tsunami", an increase in mobile broadband consumption due to faster networks, powerful devices and more traffic-demandingapplications, as well as a higher penetration volume. According to Cisco mobile data traffic is expected to grow to 15.9 exabytes per month by 2018, that is almost eleven times the mobile data traffic of 2013.

    Spectrum is a key factor for network deployments, since it determines the capacity of the network. Nonetheless, spectrum is a limited natural resource, i.e. a finite, non-exhaustible common resource. In order to fulfill the high performance targets of future mobile broadband (MBB) systems, a more efficient use and more effective management of spectrum resources have to be developed.

    Licensed Shared Access is a new complementary spectrum access scheme that allows for the sharing of partially used licensed spectrum from an incumbent (e.g. a government organization), by a limited number of “LSA licensees” (e.g. Mobile Network Operators). The LSA agreement follows pre-defined dynamic or static sharing conditions, that determine where, when and how to use the incumbent’s spectrum.

    The implementation of Licensed Shared Access needs the support of a very good regulatory framework and follow the harmonized spectrum pathway. Spectral harmonization, or the uniform allocation of frequency bands across entire region lowers the technology costs, making it easier for any country to consider its implementation. Once adpoted throughout the regions, economies of scale are achieved.

    Some first steps towards a new framework based on LSA have been given in Europe and North America, however to consider LSA as a real option, a complete analysis considering more markets is needed. It is crucial to consider how other regions around the world can be affected by this new approach in order to see if LSA is a viable option or not.

    The approach taken in this research covers the interrelations between technical, market and regulatory conditions in the Americas in order to present the possible value of LSA. The first part of the study deals with the analysis of the technical aspects of LSA. The following parts deal with under what conditions the evaluation is made. First, the study deals with the market conditions found in the Americas as a whole, to then deal with a more specific study of the market and regulatory conditions of selected countries in the region.

    The research showed how there are several ways LSA can bring positive value to established and emerging actors in the Americas, specially in high traffic areas, and/or indoor environments. However, and despite the advantages of LSA, the timing is not there yet. The region still has plenty of spectrum to be allocated as exclusive spectrum, which is preferred by operators. The low mobile broadband penetration in most of the region is also a factor for the low value of LSA in the time of this study.

  • 2353. Agustsson, J. S.
    et al.
    Agustsson, B. V.
    Eriksson, A. K.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Olafsson, S.
    Johnsen, K.
    Gudmundsson, J. T.
    Hydrogen uptake in MgO thin films grown by reactive magnetron sputtering2006Conference paper (Other academic)
    Abstract
  • 2354. Agustsson, J. S.
    et al.
    Arnalds, U. B.
    Ingason, A. S.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Johnsen, K.
    Olafsson, S.
    Gudmundsson, Jon Tomas
    University of Iceland, Iceland.
    Electrical resistivity and morphology of ultra thin Pt films grown by dc magnetron sputtering on SiO(2)2008In: Journal of Physics Conference Series, IOP Science , 2008, Vol. 100Conference paper (Refereed)
    Abstract [en]

    Ultra thin platinum films were grown by dc magnetron sputtering on thermally oxidized Si (100) substrates. The electrical resistance of the films was monitored in-situ during growth. The coalescence thickness was determined for various growth temperatures and found to increase from 1.3 nm for films grown at room temperature to 1.8 nm for films grown at 250 degrees C, while a continuous film was formed at a thickness of 3.9 nm at room temperature and 3.5 nm at 250 degrees C. The electrical resistivity increases with increased growth temperature, as well as the morphological grain size, and the surface roughness, measured with a scanning tunneling microscope (STM).

  • 2355. Agustsson, J. S.
    et al.
    Arnalds, U. B.
    Ingason, A. S.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Johnsen, K.
    Olafsson, S.
    Gudmundsson, Jon Tomas
    University of Iceland, Iceland.
    Growth, coalescence, and electrical resistivity of thin Pt films grown by dc magnetron sputtering on SiO22008In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 254, no 22, p. 7356-7360Article in journal (Refereed)
    Abstract [en]

    Ultra thin platinum films were grown by dc magnetron sputtering on thermally oxidized Si (100) substrates. The electrical resistance of the films was monitored in situ during growth. The coalescence thickness was determined for various growth temperatures and found to increase from 1.1 nm for films grown at room temperature to 3.3 nm for films grown at 400 degrees C. A continuous film was formed at a thickness of 2.9 nm at room temperature and 7.5 nm at 400 degrees C. The room temperature electrical resistivity decreases with increased growth temperature, while the in-plain grain size and the surface roughness, measured with a scanning tunneling microscope (STM), increase. Furthermore, the temperature dependence of the film electrical resistance was explored at various stages during growth.

  • 2356. Agustsson, Jon S.
    et al.
    Gylfason, Kristinn B.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Olafsson, Sveinn
    Johnsen, Kristinn
    Gudmundsson, Jon T
    Electrical properties of thin MgO films2005Conference paper (Other academic)
  • 2357.
    AGUZ, JOSEF
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    MARKIEWICZ, OSSIAN
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Exploring the Relationship Between HousingPrices and Stock Prices2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study investigates the long- and short-run relationship between stock- and housingprices in Finland, Denmark, Norway and Sweden between 1987-2017 and 1995-2017 with data from OECD statistics. By using interest rate as a control variable and Johansen's Test for Cointegration, the results show a significant relationship for Finland during the period 1995-2017. The short-run analysis implies a credit effect, which is inline with previous studies. However, in Denmark, Norway and Sweden the analysis show no sign of cointegration. A possible explanation for the insignificant results could be the high degree of policy implementations and changes to market structures in the early 1990s, which theoretically could be controlled for by including additional control variables in the analysis.

  • 2358. Agélii Genlott, Annika
    et al.
    Grönlund, Åke
    Viberg, Olga
    KTH, School of Electrical Engineering and Computer Science (EECS), Media Technology and Interaction Design, MID.
    Disseminating digital innovation in school – leading second-order educational change2019In: Education and Information Technologies: Official Journal of the IFIP technical committee on Education, ISSN 1360-2357, E-ISSN 1573-7608Article in journal (Refereed)
    Abstract [en]

    Using digital technology effectively in schools requires profound changes in traditional teaching and learning activities. Pedagogical innovations often start small-scale and developing good ideas into shared practice across schools is challenging in many ways, especially if the innovation requires second-order change, i.e. challenges to fundamental beliefs about teaching and learning. This study investigates how a validated pedagogical method requiring integrated Information and Communication Technology (ICT) use and second-order change can be disseminated and sustained over time. We surveyed 92 primary school teachers who at different times over a 5-year period participated in a training course designed to implement an innovative technology-supported teaching method, Write To Learn, across an entire city. We found that organized teacher development programs can drive second-order change, but this requires considerable, active, and sustained effort from leaders at both school and district level. Additional factors include immediate and extended social systems and handling diversity among teachers. The results are useful for both practitioners and researchers since they contribute to a deeper understanding of the opportunities and challenges involved in disseminating effective ICT-based methods that requires profound changes of thinking about teaching and learning to guide the transformation of teaching practice.

  • 2359.
    Agüero, Juan C.
    et al.
    The University of Newcastle, Australia.
    Rojas, Cristian R.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Goodwin, Graham C.
    The University of Newcastle, Australia.
    Fundamental Limitations on the Accuracy of MIMO Linear Models Obtained by PEM for Systems Operating in Open Loop2009In: Proceedings of the Joint 48th IEEE Conference on Decision and Control (CDC’09) and 28th Chinese Control Conference (CCC’09), 2009, p. 482-487Conference paper (Refereed)
    Abstract [en]

    In this paper we show that the variance of estimated parametric models for open loopMultiple-Input Multiple-Output (MIMO) systems obtained by the prediction error method (PEM) satisfies a fundamental integral limitation. The fundamental limitation gives rise to a multivariable 'water-bed' effect.

  • 2360.
    Agüero, Juan C.
    et al.
    The University of Newcastle, Australia.
    Rojas, Cristian R.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Goodwin, Graham C.
    The University of Newcastle, Australia.
    Accuracy of linear multiple-input multiple-output (MIMO) models obtained by maximum likelihood estimation2012In: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 48, no 4, p. 632-637Article in journal (Refereed)
    Abstract [en]

    In this paper, we study the accuracy of linear multiple-input multiple-output (MIMO) models obtained by maximum likelihood estimation. We present a frequency-domain representation for the information matrix for general linear MIMO models. We show that the variance of estimated parametric models for linear MIMO systems satisfies a fundamental integral trade-off. This trade-off is expressed as a multivariable 'water-bed' effect. An extension to spectral estimation is also discussed.

  • 2361.
    Agüero, Ramón
    et al.
    University of Cantabria, Spain.
    Berg, Miguel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Choque, Johnny
    University of Cantabria, Spain.
    Hultell, Johan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Jennen, Ralf
    RWTH Aachen University, Germany.
    Markendahl, Jan
    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.
    Muñoz, Luis
    University of Cantabria, Spain.
    Prytz, Mikael
    Ericsson Research.
    Strandberg, Ove
    Nokia, Finland.
    RRM Challenges for Non-Conventional and Low-Cost Networks in Ambient Networks2005Conference paper (Refereed)
    Abstract [en]

    This paper presents an overview of the Radio Resource Management (RRM) functionalities needed for Non-Conventional and Low-Cost Networks. These types of networks are characterized by increased cooperation between different types of networks and providers and they are believed to play a fundamental role for future wireless network networking. The paper describes three specific concepts, which latter is used to identify new RRM challenges. In addition, it identifies the relation between the RRM challenges and the Ambient Networks architecture and functionalities, in particular the multiradio resource management functionality.

  • 2362. Ahangar Zonouzi, S.
    et al.
    Khodabandeh, Rahmatollah
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Safarzadeh, H.
    Aminfar, H.
    Trushkina, Y.
    Mohammadpourfard, M.
    Ghanbarpour, Morteza
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Salazar Alvarez, G.
    Experimental investigation of the flow and heat transfer of magnetic nanofluid in a vertical tube in the presence of magnetic quadrupole field2018In: Experimental Thermal and Fluid Science, ISSN 0894-1777, E-ISSN 1879-2286, Vol. 91, p. 155-165Article in journal (Refereed)
    Abstract [en]

    In this paper, the effects of applying magnetic field on hydrodynamics and heat transfer of Fe3O4/water magnetic nanofluid flowing inside a vertical tube have been studied experimentally. The applied magnetic field was resulted from quadrupole magnets located at different axial positions along the tube length. The variations of the local heat transfer coefficient and also the pressure drop of the ferrofluid flow along the length of the tube by applying the magnetic quadrupole field have been investigated for different Reynolds numbers. The obtained experimental results show maximum enhancements of 23.4%, 37.9% and 48.9% in the local heat transfer coefficient for the magnetic nanofluid with 2 vol% Fe3O4 in the presence of the quadrupole magnets located at three different axial installation positions for the Reynolds number of 580 and the relative increase in total pressure drop by applying the magnetic field is about 1% for Re = 580. The increase of the heat transfer coefficient is due to the radial magnetic force toward the heated wall generated by magnetic quadrupole field acting over the ferrofluid flowing inside the tube so that the velocity of the ferrofluid in the vicinity of the heated wall is increased. It is also observed that the enhancement of heat transfer coefficient by applying magnetic quadrupole is decreased with increasing the Reynolds number.

  • 2363.
    Ahari, Parviz
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    A living systems analysis of student design projects at the Royal Institute of Technology (KTH)2006In: Systems research and behavioral science, ISSN 1092-7026, E-ISSN 1099-1743, Vol. 23, no 3, p. 419-428Article in journal (Refereed)
    Abstract [en]

    Student evaluations of courses are routinely obtained by questionnaire in higher education. That student feedback is used for, among other purposes, the planning of future courses. Whether such questionnaires consider, in specific situations, all aspects of the educational processes, or even the important ones, is an open question. This study examines that question with reference to a particular engineering design course. It investigates how groups of students process information in their design projects. The study uses the breakthrough, or full-spectrum, thinking explained by Nadler, Hibino, with Farrell to understand the uniqueness of the situation and to clarify the purposes of the research. Living systems theory instructs the design of research instruments and of a research hypothesis. The results show that significant differences in information processing exist between lower performing and higher performing groups.

  • 2364.
    Ahari, Parviz
    KTH, Superseded Departments, Machine Design.
    A living systems approach to product design and development2003Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    Product development is a complex activity that involvespeople with different expertise, financial resources,materials, and machines. Organizations that carry out theseprocesses and their products are in fact living and artificialsystems. The concept of system is therefore very important fordealing with complexity of products, and their developmentprocesses. However, the concept of system is not consideredcarefully and scientifically in this context, therefore itsexplanations in design and development literature havelimitations and do not provide sufficient help for those whoare involved in the complex processes of product design anddevelopment.

    In this research an attempt is made to show the relevance ofsystems concepts for product development. The purpose of thisresearch is therefore to provide knowledge, and betteralternative points of view that helps to manage complexities ofproducts and product development processes, to improveunderstanding of them, to avoid problems related toconventional thinking, and to complement conventionalmethods.

    To provide this knowledge the weaknesses of the conventionalmethods of product development and the strengths ofunconventional systemic methods have been shown. Systemsthinking as an unconventional method has been introduced anddiscussed. These presentations include the need for a newscientific method, the meaning of system, its origin, kinds ofsystems, why, and how systems sciences are applied. Further theneed for and importance of a better theory in product designand development is shown. Living systems theory (LST) isintroduced, and explained. LST’s applications in differentdisciplines are presented. The research includes also adiscussion of the meaning of products, their places in livingsystems and what triggers their design and development.

    The importance of creativity, innovation, and lifelonglearning are emphasized and discussed. It has been shown howliving systems theory and other systems sciences can contributeto them. The relevance of how we see the world is discussed andit has been shown how we can and should improve our way ofseeing the world. It has also been shown that information andknowledge are not sufficient. We should also become wiser, andthis requires consideration of the long-term consequences ofour actions and it involves values and judgment.

    The results of this research are both descriptive andprescriptive. They provide several contributions, for example,a systemic cube (table) of artifacts (analogous withMendeleyev’s table of elements) as a model for managingcomplexity and for generating creative ideas; and a new conceptof usability engineering, which has been applied in industry indifferent projects. Further a more complete LST based model,which can be used for products and product developmentprocesses (for living and artificial systems), has beenprovided. The research uncovers also neglected aspects of LSTin product design and development and shows how they can beconsidered, these are for example the concepts of alpha- beta-,and gamma-coded information. It has also been shown how we canacquire a more complete understanding of product developmentactivities and how we can improve these processes. Thesecontributions have both academic and industrial relevance andpresent a step in the right direction–improving thequality of life.

    Keywords:Product design and development, living systemstheory, needs, managing complexity, modeling, systems thinking,problem solving, creativity, lifelong learning.

  • 2365. Aharonian, F.
    et al.
    Akhperjanian, A. G.
    Anton, G.
    Barres De Almeida, U.
    Bazer-Bachi, A. R.
    Becherini, Y.
    Behera, B.
    Bernloehr, K.
    Boisson, C.
    Bochow, A.
    Borrel, V.
    Brion, E.
    Brucker, J.
    Brun, P.
    Buehler, R.
    Bulik, T.
    Buesching, I.
    Boutelier, T.
    Chadwick, P. M.
    Charbonnier, A.
    Chaves, R. C. G.
    Cheesebrough, A.
    Chounet, L. -M
    Clapson, A. C.
    Coignet, G.
    Dalton, M.
    Daniel, M. K.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    Dickinson, H. J.
    Djannati-Ata, A.
    Domainko, W.
    O'C. Drury, L.
    Dubois, F.
    Dubus, G.
    Dyks, J.
    Dyrda, M.
    Egberts, K.
    Emmanoulopoulos, D.
    Espigat, P.
    Farnier, C.
    Feinstein, F.
    Fiasson, A.
    Foerster, A.
    Fontaine, G.
    Fuessling, M.
    Gabici, S.
    Gallant, Y. A.
    Gerard, L.
    Giebels, B.
    Glicenstein, J. F.
    Glueck, B.
    Goret, P.
    Goehring, D.
    Hauser, D.
    Hauser, M.
    Heinz, S.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hinton, J. A.
    Hoffmann, A.
    Hofmann, W.
    Holleran, M.
    Hoppe, S.
    Horns, D.
    Jacholkowska, A.
    De Jager, O. C.
    Jahn, C.
    Jung, I.
    Katarzyński, K.
    Katz, U.
    Kaufmann, S.
    Kendziorra, E.
    Kerschhaggl, M.
    Khangulyan, D.
    Khélifi, B.
    Keogh, D.
    Kluzniak, W.
    Komin, N.
    Kosack, K.
    Lamanna, G.
    Lenain, J. -P
    Lohse, T.
    Marandon, V.
    Martin, J. M.
    Martineau-Huynh, O.
    Marcowith, A.
    Maurin, D.
    McComb, T. J. L.
    Medina, M. C.
    Moderski, R.
    Moulin, E.
    Naumann-Godo, M.
    De Naurois, M.
    Nedbal, D.
    Nekrassov, D.
    Niemiec, J.
    Nolan, S. J.
    Ohm, S.
    Olive, J. -F
    De Wilhelmi, E.
    Orford, K. J.
    Ostrowski, M.
    Panter, M.
    Arribas, M. P.
    Pedaletti, G.
    Pelletier, G.
    Petrucci, P. -O
    Pita, S.
    Paehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raubenheimer, B. C.
    Raue, M.
    Rayner, S. M.
    Renaud, M.
    Rieger, F.
    Ripken, J.
    Rob, L.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Ruppel, J.
    Sahakian, V.
    Santangelo, A.
    Schlickeiser, R.
    Schock, F. M.
    Schröder, R.
    Schwanke, U.
    Schwarzburg, S.
    Schwemmer, S.
    Shalchi, A.
    Sikora, M.
    Skilton, J. L.
    Sol, H.
    Spangler, D.
    Stawarz, Ł.
    Steenkamp, R.
    Stegmann, C.
    Superina, G.
    Szostek, A.
    Tam, P. H.
    Tavernet, J. -P
    Terrier, R.
    Tibolla, O.
    Van Eldik, C.
    Vasileiadis, G.
    Venter, C.
    Venter, L.
    Vialle, J. P.
    Vincent, P.
    Vivier, M.
    Vaelk, H. J.
    Volpe, F.
    Wagner, S. J.
    Ward, M.
    Zdziarski, A. A.
    Zech, A.
    Abdo, A. A.
    Ackermann, M.
    Ajello, M.
    Atwood, W. B.
    Axelsson, Magnus
    Department of Astronomy, Stockholm University.
    Baldini, L.
    Ballet, J.
    Barbiellini, G.
    Baring, M. G.
    Bastieri, D.
    Battelino, Milan
    KTH, School of Engineering Sciences (SCI), Physics.
    Baughman, B. M.
    Bechtol, K.
    Bellazzini, R.
    Berenji, B.
    Bloom, E. D.
    Bonamente, E.
    Borgland, A. W.
    Bregeon, J.
    Brez, A.
    Brigida, M.
    Bruel, P.
    Caliandro, G. A.
    Cameron, R. A.
    Caraveo, P. A.
    Casandjian, J. M.
    Cavazzuti, E.
    Cecchi, C.
    Charles, E.
    Chekhtman, A.
    Chen, A. W.
    Cheung, C. C.
    Chiang, J.
    Ciprini, S.
    Claus, R.
    Cohen-Tanugi, J.
    Colafrancesco, S.
    Conrad, Jan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Costamante, L.
    Cutini, S.
    Dermer, C. D.
    De Angelis, A.
    De Palma, F.
    Digel, S. W.
    Do Couto E Silva, E.
    Drell, P. S.
    Dubois, R.
    Dumora, D.
    Favuzzi, C.
    Fegan, S. J.
    Ferrara, E. C.
    Fleury, P.
    Focke, W. B.
    Frailis, M.
    Fukazawa, Y.
    Funk, S.
    Fusco, P.
    Gargano, F.
    Gasparrini, D.
    Gehrels, N.
    Germani, S.
    Giglietto, N.
    Giordano, F.
    Grondin, M. -H
    Grove, J. E.
    Guillemot, L.
    Guiriec, S.
    Hanabata, Y.
    Harding, A. K.
    Hayashida, M.
    Hays, E.
    Horan, D.
    Jóhannesson, G.
    Johnson, A. S.
    Johnson, R. P.
    Johnson, W. N.
    Kadler, M.
    Kamae, T.
    Katagiri, H.
    Kataoka, J.
    Kerr, M.
    Knödlseder, J.
    Kuehn, F.
    Kuss, M.
    Lande, J.
    Latronico, L.
    Lee, S. -H
    Lemoine-Goumard, M.
    Longo, F.
    Loparco, F.
    Lott, B.
    Lovellette, M. N.
    Madejski, G. M.
    Makeev, A.
    Mazziotta, M. N.
    McEnery, J. E.
    Meurer, C.
    Michelson, P. F.
    Mitthumsiri, W.
    Mizuno, T.
    Moiseev, A. A.
    Monte, C.
    Monzani, M. E.
    Morselli, A.
    Moskalenko, I. V.
    Murgia, S.
    Nolan, P. L.
    Nuss, E.
    Ohsugi, T.
    Omodei, N.
    Orlando, E.
    Ormes, J. F.
    Paneque, D.
    Panetta, J. H.
    Parent, D.
    Pelassa, V.
    Pepe, M.
    Pesce-Rollins, M.
    Piron, F.
    Porter, T. A.
    Rainò, S.
    Razzano, M.
    Reimer, A.
    Reimer, O.
    Reposeur, T.
    Ritz, S.
    Rodriguez, A. Y.
    Ryde, Felix
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Sadrozinski, H. F. -W
    Sanchez, D.
    Sander, A.
    Scargle, J. D.
    Schalk, T. L.
    Sellerholm, A.
    Sgro, C.
    Shaw, M.
    Smith, D. A.
    Spandre, G.
    Spinelli, P.
    Starck, J. -L
    Strickman, M. S.
    Tajima, H.
    Takahashi, H.
    Takahashi, T.
    Tanaka, T.
    Thayer, J. G.
    Thompson, D. J.
    Tibaldo, L.
    Torres, D. F.
    Tosti, G.
    Tramacere, A.
    Uchiyama, Y.
    Usher, T. L.
    Vilchez, N.
    Villata, M.
    Vitale, V.
    Waite, A. P.
    Wood, K. S.
    Ylinen, Tomi
    KTH, School of Engineering Sciences (SCI), Physics.
    Ziegler, M.
    Simultaneous observations of pks 2155-304 with hess, fermi, rxte, and atom: Spectral energy distributions and variability in a low state2009In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 696, no 2 PART 2, p. L150-L155Article in journal (Refereed)
    Abstract [en]

    We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of gamma-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; > 100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little (similar to 30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated variability we find in the various bands for PKS 2155-304.

  • 2366. Aharonov, Dov
    et al.
    Shapiro, Harold S.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    Solynin, Alexander Yu.
    Minimal area problems for functions with integral representation2006In: Journal d'Analyse Mathematique, ISSN 0021-7670, E-ISSN 1565-8538, Vol. 98, p. 83-111Article in journal (Refereed)
    Abstract [en]

    We study the minimization problem for the Dirichlet integral in some standard classes of analytic functions. In particular, we solve the minimal area a(2)-problern for convex functions and for typically real functions. The latter gives a new solution to the minimal area a(2)-problem for the class S of normalized univalent functions in the unit disc.

  • 2367. Aharrouche, M.
    et al.
    Adam-Bourdarios, C.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Zhang, H.
    Grahn, Karl-Johan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lafaye, Remi
    Univ Savoie, LAPP, CNTS IN2P3, Annecy Le Vieux, France.
    Measurement of the response of the ATLAS liquid argon barrel calorimeter to electrons at the 2004 combined test-beam2010In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 614, no 3, p. 400-432Article in journal (Refereed)
    Abstract [en]

    During summer and fall 2004, the response of a full slice of the ATLAS barrel detector to different particles was studied in controlled beam. One module of the ATLAS liquid argon barrel calorimeter identical to the production modules and read out by the final front-end and back-end electronics was used for electromagnetic calorimetry. This paper presents and discusses the electron performance of the LAr barrel calorimeter, including linearity, uniformity, and resolution with different amounts of material upstream the calorimeter and energies ranging from 1 to 250 GeV.

  • 2368. Aharrouche, M.
    et al.
    Colas, J.
    Di Ciaccio, L.
    El Kacimi, M.
    Kerschen, N.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lafaye, Remi
    Univ Savoie, LAPP, CNTS IN2P3, Annecy Le Vieux, France.
    et, al
    Time resolution of the ATLAS barrel liquid argon electromagnetic calorimeter2008In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 597, no 2-3, p. 178-188Article in journal (Refereed)
    Abstract [en]

    The time reconstruction performance of the ATLAS electromagnetic calorimeter readout is studied. The contribution of the electronics to the time resolution is estimated to be about 20 ps, thus demonstrating the possibility of achieving a small constant term in the time resolution for particles. The resolution to electromagnetic showers produced by an electron beam is also measured. After correction for the effects due to the calorimeter geometry, a 100 ps constant term is found for a typical cell.

  • 2369. Aharrouche, M.
    et al.
    Colas, J.
    Di Ciaccio, L.
    El Kacimi, M.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Tayalati, Y.
    Lafaye, Remi
    Univ Savoie, LAPP, CNTS IN2P3, Annecy Le Vieux, France.
    et, al
    Energy linearity and resolution of the ATLAS electromagnetic barrel calorimeter in an electron test-beam2006In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 568, no 2, p. 601-623Article in journal (Refereed)
    Abstract [en]

    A module of the ATLAS electromagnetic barrel liquid argon calorimeter was exposed to the CERN electron test-beam at the H8 beam line upgraded for precision momentum measurement. The available energies of the electron beam ranged from 10 to 245 GeV. The electron beam impinged at one point corresponding to a pseudo-rapidity of eta = 0.687 and an azimuthal angle of phi = 0.28 in the ATLAS coordinate system. A detailed study of several effects biasing the electron energy measurement allowed an energy reconstruction procedure to be developed that ensures a good linearity and a good resolution. Use is made of detailed Monte Carlo simulations based on GEANT4 which describe the longitudinal and transverse shower profiles as well as the energy distributions. For electron energies between 15 and 180 GeV the deviation of the measured incident electron energy over the beam energy is within 0.1%. The systematic uncertainty of the measurement is about 0.1% at low energies and negligible at high energies. The energy resolution is found to be about 10%. root E for the sampling term and about 0.2% for the local constant term.

  • 2370. Aharrouche, M.
    et al.
    Colas, J.
    Di Ciaccio, L.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Tayalati, Yahya
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lafaye, Remi
    Univ Savoie, LAPP, CNTS IN2P3, Annecy Le Vieux, France.
    Study of the response of ATLAS electromagnetic liquid argon calorimeters to muons2009In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 606, no 3, p. 419-431Article in journal (Refereed)
    Abstract [en]

    The response of the ATLAS electromagnetic calorimeter to muons has been studied in this paper. Results on signal over noise ratio, assessment of the detector response uniformity, and position resolution are presented. The possibility to study fine details of the structure of the detector through its response to muons is illustrated on a specific example. Finally, the performance obtained on muons in test-beam is used to estimate the detector uniformity and time alignment precision that will be reachable after the commissioning of the ATLAS detector with cosmic rays.

  • 2371. Aharrouche, M.
    et al.
    Colas, J.
    Maaroufi, F.
    Cleland, W.
    Lacour, D.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lafaye, Remi
    Univ Savoie, LAPP, CNTS IN2P3, Annecy Le Vieux, France.
    et, al
    Response uniformity of the ATLAS liquid argon electromagnetic calorimeter2007In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 582, no 2, p. 429-455Article in journal (Refereed)
    Abstract [en]

    The construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize the complete energy reconstruction chain from the readout and calibration electronics to the signal and energy reconstruction. It was also possible to check the full Monte Carlo simulation of the calorimeter. The analysis of the uniformity, resolution and extraction of constant term is presented. Typical non-uniformities of 5 parts per thousand and typical global constant terms of 6 parts per thousand are measured for the barrel and endcap modules.

  • 2372.
    Ahl, Amanda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Eklund, Johanna
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    A Study of the Potential and Energy Balance of the Emergency Energy Module in Mozambique2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study investigates the potential for implementation of a solar PV-biodiesel hybrid system with battery storage in two rural villages in the Cabo Delgado province in Mozambique. These villages, Nicuita and Quirimize, have at present very limited access to electricity which greatly inhibits an increase in living standards and development of the respective communities.

     

    Based on the results of conducted surveys mapping potential electricity demand, the load profiles of the villages alongside an investigation of the availability of different resources are the input of the model of this study with which appropriate dimensions of the hybrid system are suggested for each village.

     

    The targeted biofuel of the solar PV-biodiesel hybrid parallel configuration suggested in this study is jatropha based biodiesel for both Nicuita and Quirimize. The biodiesel fueled diesel generator and battery storage meets the nighttime load of the villages, while the solar PV system meets the load during daylight hours and also charges the battery bank to supply the nighttime load not covered by the diesel generator. The electricity production of the hybrid system is distributed through a mini-grid.

  • 2373.
    Ahl, Amanda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Eklund, Johanna
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Success Factor of Woody Biomass Supply Chains in Japan2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    There is an abundance of forest in Japan, yet a lack of utilization of woody biomass in energy systems. Small-scale woody biomass can enable a supply chain based on domestic forest integrated with local industry and demands, in turn facilitating local vitalization. Successful creation of collective energy systems is strongly connected to supply chain design based on local conditions and stakeholder integration. A supply chain perspective is key in enabling woody biomass energy systems. In these supply chains lies a complex stakeholder network across different industries, in turn incurring a need to understand both formal factors, such as technology, and informal factors, such as social relations and culture across these industries.The purpose of this study is to investigate the main challenges, success factors and convergence or divergence of perceptions of key stakeholders across the supply chain of small-scale woody biomass energy systems in Japan. In this study, the concept of small-scale woody biomass involves a supply chain based on domestic forest and integrated with local supply and demand. If the challenges and success factors, as well as balance of perceptions, can be highlighted and managed, small-scale woody biomass can be enabled by incorporating a system’s approach in supply chain analysis. This study employs a methodology incorporating literature studies and semi-structured interviews with experts to create an initial “pentagon model” presenting hypothesized success factors, including both formal and informal elements divided into five categories: technology, structure, social relations & network, culture and interaction. This is a base for the case studies, involving in-depth, semi-structured interviews with four key stakeholders in the woody biomass energy system supply chain, exploring their perceived challenges and success factors. The case studies are carried in Kyushu, the southernmost of the Japanese main islands, known for an abundance of forest alongside activity in the field of woody biomass.The main success factors emphasized by one or more of the interviewed case study stakeholders are respect of values & traditions, transportation infrastructure, business model integration, relationship & trust, local vitalization and biomass quality control. Interesting findings related to the relative success factor perceptions include the high emphasis in the upstream supply chain on respect & traditions of the forest industry, and lack of emphasis downstream. Moreover, biomass quality control is more discussed by the downstream supply chain as a main success factor. The success factors and balance of perceptions found in this study indicate the importance of both informal and formal elements in supply chain success, as well as managing a potential imbalance of perceptions. This study is meant to serve as a base for further studies on factors of the woody biomass energy system supply chain, and promote a system’s approach incorporating both formal and informal aspects in this research.

  • 2374.
    Ahl, Amanda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Eklund, Johanna
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Lundqvist, Per
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Yarime, M.
    Balancing formal and informal success factors perceived by supply chain stakeholders: A study of woody biomass energy systems in Japan2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 175, p. 50-59Article in journal (Refereed)
    Abstract [en]

    Small-scale woody biomass energy systems have an inherent ability to aid in emissions reduction while stimulating local economies and, as collective energy systems, are strongly connected to supply chain design based on local conditions and stakeholder integration. Despite an abundance of forest area alongside the promotion of biomass in energy policies, however, woody biomass utilization still remains low in Japan. The woody biomass supply chain, considered as a socio-technical system, involves a complex, cross-sectoral stakeholder network in which inter-organizational dynamics necessitates well-organized management based on an understanding of formal factors such as technology, as well as informal factors such as social relations and culture. In this paper, success factor perceptions from across the woody biomass supply chain are investigated based on semi-structured interviews with four stakeholders in the Kyushu region of Japan. Identified success factors here are: 1) respect of values & traditions, 2) transportation infrastructure, 3) business model integration, 4) relationship & trust, 5) local vitalization and 6) biomass quality control. A convergence as well as divergence of perceptions are observed, involving both formal and informal dimensions. Aiming to balance perceptions and to enable long-term success of woody biomass in Japan, a series of policy implications are drawn, including cross-ministerial integration, knowledge building on wood logistics, forest certification, local coordinators, biomass quality control standards and a feed-in-tariff for heat. This paper suggests a new arena of policy-making based on the importance of considering both informal and formal dimensions in energy policy.

  • 2375.
    Ahl Eliasson, Johan
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Projecting Realities: Re-mediation in the Realm of Architecture2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The boundaries between physical and virtual are dissolving as worlds are superimposed through media saturation. The design proposal of a movie theater at S:t Eriksgatan in Stockholm acts as vehicle for exploring the opportunities of architecture in an unstable reality. Remediation. A concept within media studies, describes the way any new media incorporates the traits of already existing ones. Conversely, “(…)older media refashion themselves to answer the challenges of new media”(1).

    By regarding architecture as a world-conjuring operation, parallel investigations into other media provide new tools of design. The method consists of simultaneously developing five works in five media: text, image, diorama, video and architecture. The text serves as abinding narrative. The image is based on an analysis of Giovanni Battista Piranesis prison etchings wich exhibit a range of devices particular to the world of image. The diorama or mirror box is an attempt to create a boundless but contained world. The video world has centered around the use of a reverse zoom effect. The movie theater uses the techniques of media in order to enhance it´s immersive qualities.

    (1) BOLTER & GRUSIN, Jay David & Richard (2000) Remediation: Understanding New Media, USA: MIT Press, p. 19.

  • 2376.
    Ahl Eliasson, Johan
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Tillbyggnad till Nationalmuseum2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the work is to design an extension to The National Museum in Stockholm. The current facilities are going to be reorganized in a near future. Conservation of artworks, research and administration, today housed in the museum building, will be moved to an extension. The current addition, built in the 1960s will be torn down. The extension designed in this work is placed behind (north of) The National Museum. A smaller body of four stories act as prime motif and include entrances, offices, research rooms, library and main vertical communication of the extension. This volume lies parallel to the original building. In a small angle to the first body a lower but very elongated volume lies, it is a continuation of the apparent urban grid. It includes the conservation studios and forms a solid granite wall toward the National Museum and the sculpture park created between them. The park becomes a new, identifiable space in the city, in a way targeting the modern museum of art across the water.

  • 2377.
    Ahlawat, Paramvir
    KTH, School of Chemical Science and Engineering (CHE).
    Modellering och implementering av simultan dubbel gradient kromatografi2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Polypeptides are becoming an important component of the antibiotic therapeutics. The production demand of therapeutic polypeptides is increasing and there is a significant interest in developing more efficient production processes. In pharmaceutical industries, polypeptides are produced as a crude mixture. Reverse phase high performance liquid chromatography (RP HPLC) is used as a typical separation technique to purify the target polypeptide from other impurities. Currently organic modifier gradients are used to elute product peptides separately from impurities. In this work, we add a second, simultaneous counter-ion gradient, in the hope of increasing separation performance and call it double gradient reverse phase chromatography. A general procedure of the model-based optimization of a polypeptide crude mixture purification process was followed to evaluate the effects of the double gradients on industrial chromatographic process. The target polypeptide elution profile was modeled with a bi-Langmuir adsorption equilibrium isotherm. The isotherm parameters of the target polypeptide were estimated by the inverse method. The model parameters of the impurities were regressed from experimental data. The variations of the isotherm parameters with the modifier concentration and counter-ion concentration were taken into account of the adsorption model. After model calibration and validation by comparison with suitable experimental data, Pareto optimization of the process were carried out to analyze the differences between single gradient chromatography and double gradient chromatography. It was observed that the additional linear gradient of counter-ion concentration did not improve the separation process. Conclusively we were able to demonstrate the concept of double gradient reverse phase chromatography within limited time and possible least experimental efforts.

  • 2378. Ahlberg, Beth Maina
    et al.
    Maina, Faith
    Kubai, Anne
    Khamasi, Wanjiku
    Ekman, Marianne
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Organization and management.
    Lundqvist-Persson, Cristina
    "A child, a tree": Challenges in building collaborative relations in a community research project in a Kenyan context2016In: Action Research, ISSN 1476-7503, E-ISSN 1741-2617, Vol. 14, no 3, p. 257-275Article in journal (Refereed)
    Abstract [en]

    This paper highlights the potential for basing participatory action research on priorities identified by communities. The case builds on a research project by the Social Science Medicine Africa Network (Soma-net) focusing on AIDS prevention among school youth in Kajiado in Kenya during 2003-2006. It became clear from that study just how complex it is to promote open communication on issues of sexuality considered critical for sexual health promotion. Towards the end of that study a spin-off in the form of a concept a child, a tree or tree planting evolved and the research thereafter continued as a partnership between the school community and the researchers. The focus then was on understanding how health promotion could be integrated into other aspects of community life. The concept and tree planting when implemented created a sense of ownership among the pupils largely because they were placed at the centre of the development activities. The story illuminates the nature of change developing in the course of the project, but also the challenges and complexity of creating and maintaining collaborative relations in the face of cultural and gender power dynamics and interventions imposed from outside the community.

  • 2379.
    Ahlberg, Carl Daniel
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Mauritz, Wera
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Modeling Far Ultraviolet Auroral Ovals at Ganymede2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Ganymede, one of Jupiters moons, differs from other moons in the Solar System as it has its own magnetic field. This rare property shapes the morphology on the existing far ultraviolet oxygen auroral ovals on the celestial body in the northern and southern hemisphere created by high energy electrons colliding into the atmosphere.With the help of the Hubble Space Telescope (HST) this phenomenon has been captured and analyzed multiple times during the past 20 years using the on-board Space Telescope Imaging Spectrograph (STIS). The ultimate goal of this project is recreating the far ultraviolet oxygen auroral emissions on Ganymede as a 3D computer model in MATLAB by using the data recovered from HST.The method used to reach this goal was to implement a model with main characteristics of the auroral ovals, project it onto a plane and then use a Cauchy distribution to filter the model. To compare the model with images from HST, a χ2-value was calculated for every pixel in each image. To further improvethe model the Nelder-Mead Simplex optimization method was applied.The project succeeded in such a way that the final model created views of the locations and the appearance of the bright spots that represent the auroral ovals around Ganymede with an accurate result in relation to the given data.

  • 2380.
    Ahlberg, Charlotte
    KTH, School of Engineering Sciences (SCI), Mechanics.
    An experimental study of fiber suspensions between counter-rotating discs2009Licentiate thesis, monograph (Other academic)
    Abstract [en]

    The behavior of fibers suspended in a flow between two counter-rotating discs has been studied experimentally. This is inspired by the refining process in the papermaking process where cellulose fibers are ground between discs in order to change performance in the papermaking process and/or qualities of the final paper product.

    To study the fiber behavior in a counter-rotating flow, an experimental set-up with two glass discs was built. A CCD-camera was used to capture images of the fibers in the flow. Image analysis based on the concept of steerable filters extracted the position and orientation of the fibers in the plane of the discs. Experiments were performed for gaps of 0.1-0.9 fiber lengths, and for equal absolute values of the angular velocities for the upper and lower disc. The aspect ratios of the fibers were 7, 14 and 28.

    Depending on the angular velocity of the discs and the gap between them, the fibers were found to organize themselves in fiber trains. A fiber train is a set of fibers positioned one after another in the tangential direction with a close to constant fiber-to-fiber distance. In the fiber trains, each individual fiber is aligned in the radial direction (i.e. normal to the main direction of the train).

    The experiments show that the number of fibers in a train increases as the gap between the discs decreases. Also, the distance between the fibers in a train decreases as the length of the train increases, and the results for short trains are in accordance with previous numerical results in two dimensions.Furthermore, the results of different aspect ratios imply that there are three-dimensional fiber end-effects that are important for the forming of fiber trains.

  • 2381.
    Ahlberg, Charlotte
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Lundell, Fredrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Soderberg, L. Daniel
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    SELF-ORGANIZATION OF FIBERS IN A SUSPENSION BETWEEN TWO COUNTER-ROTATING DISCS2009In: PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 1, PTS A-C, NEW YORK: AMER SOC MECHANICAL ENGINEERS , 2009, p. 585-592Conference paper (Refereed)
    Abstract [en]

    The behavior of fibers suspended in a flow between two flat counter-rotating discs has been studied experimentally. Captured images of the fibers in the flow were analyzed by steerable filters, to extract positions and orientations of the fibers. Experiments were performed for gaps between the discs of less than one fiber length, and for equal absolute values of the angular velocities for the discs. The length-to-diameter ratio of the fibers was approximately 14. During certain conditions, the fibers organized themselves in a distinct manner, which we will denote as fiber trains, in which three or more fibers are aligned next to each other, at the same radial position, with a short fiber-to-fiber distance. The direction of the individual fibers is radial and the direction of the whole train is tangential. Trains containing more than 60 fibers have been observed and are quite impressing.

  • 2382.
    Ahlberg, Erik
    KTH, School of Engineering Sciences (SCI).
    Verication and evaluation of the DREAM model for subphotospheric dissipation in prompt GRB emission2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Gamma-ray bursts (GRBs) are among the most energetic events in the universe, lasting only seconds and for that brief time outshining all other gamma-ray sources in the universe. However, after decades of studies the emission processes of the prompt  gamma-ray emission phase is still not well understood. A suggested model is the Dissipation with Radiative Emission as A table Model (DREAM). In this thesis a series of systematic tests were performed to test different implementations the DREAM model. The aim was to quantify different kinds of uncertainties in the model, and make suggestions for improvements. 

    The models were tested for their dependence in signal-to-noise ratio, how the interpolation of spectra affect the result, and any degeneracies. An optimum signal-to-noise ratio of 40-100 was found. The systematic errors due to using interpolated spectra were found  to be 10-15% in most of the parameter space and to never exceed the estimated uncertainties arising from assumptions made in the physical scenario. In more than ~ 80% of the parameter space, no strong degeneracies were found. The degenerate region is characterized by a small fraction of the dissipated energy going to the electrons. 

  • 2383.
    Ahlberg, Erik
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Hasan, Samin
    KTH, School of Engineering Sciences (SCI), Physics.
    Optimising a small satellite for hard X-ray polarisation studies of gamma ray Bursts.2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Gamma ray bursts (GRBs) originate from extremely energetic extra-galactic events, and

    much is still unknown about them. Whereas the energy and time structure of GRBs

    have been studied extensively the past years, only a few polarisation measurements have

    been made on their initial, prompt emission. Determining the polarisation of GRBs will

    therefore provide a means to test proposed emission models. A small satellite (SPHiNX)

    has been proposed to measure the polarisation of X-rays from GRBs.

    The performance of the detector is optimised using Monte Carlo simulations of a typical

    GRB source, in order to produce a more efficient design. First, the effect on the performance

    when varying individual parameters is studied, and then when using several

    changes in conjunction for the optimisation. The new design improves the primary gure

    of merit, the minimum detectable polarisation (MDP), by

    7% over the initial design, and

    improves the secondary gure of merit, the effective area, by 22%.

  • 2384.
    Ahlberg, Ernst
    et al.
    Predictive Compound ADME & Safety, Drug Safety & Metabolism, AstraZeneca IMED Biotech Unit, Mölndal, Sweden.
    Winiwarter, Susanne
    Predictive Compound ADME & Safety, Drug Safety & Metabolism, AstraZeneca IMED Biotech Unit, Mölndal, Sweden.
    Boström, Henrik
    Department of Computer and Systems Sciences, Stockholm University, Sweden.
    Linusson, Henrik
    Department of Information Technology, University of Borås, Sweden.
    Löfström, Tuve
    Högskolan i Jönköping, JTH. Forskningsmiljö Datavetenskap och informatik.
    Norinder, Ulf
    Swetox, Karolinska Institutet, Unit of Toxicology Sciences, Sweden.
    Johansson, Ulf
    Högskolan i Jönköping, JTH, Datateknik och informatik.
    Engkvist, Ola
    External Sciences, Discovery Sciences, AstraZeneca IMED Biotech Unit, Mölndal, Sweden.
    Hammar, Oscar
    Quantitative Biology, Discovery Sciences, AstraZeneca IMED Biotech Unit, Mölndal, Sweden.
    Bendtsen, Claus
    Quantitative Biology, Discovery Sciences, AstraZeneca IMED Biotech Unit, Cambridge, UK.
    Carlsson, Lars
    Quantitative Biology, Discovery Sciences, AstraZeneca IMED Biotech Unit, Mölndal, Sweden.
    Using conformal prediction to prioritize compound synthesis in drug discovery2017In: Proceedings of Machine Learning Research: Volume 60: Conformal and Probabilistic Prediction and Applications, 13-16 June 2017, Stockholm, Sweden / [ed] Alex Gammerman, Vladimir Vovk, Zhiyuan Luo, and Harris Papadopoulos, 2017, p. 174-184Conference paper (Refereed)
    Abstract [en]

    The choice of how much money and resources to spend to understand certain problems is of high interest in many areas. This work illustrates how computational models can be more tightly coupled with experiments to generate decision data at lower cost without reducing the quality of the decision. Several different strategies are explored to illustrate the trade off between lowering costs and quality in decisions.

    AUC is used as a performance metric and the number of objects that can be learnt from is constrained. Some of the strategies described reach AUC values over 0.9 and outperforms strategies that are more random. The strategies that use conformal predictor p-values show varying results, although some are top performing.

    The application studied is taken from the drug discovery process. In the early stages of this process compounds, that potentially could become marketed drugs, are being routinely tested in experimental assays to understand the distribution and interactions in humans.

  • 2385.
    Ahlberg, Fanny
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ökad avbördningskapacitet hos befintliga dammar i Sverige: En fallstudie över damm i mellersta Norrland2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Intresset för klimatförändringar, och problem som kommer med dessa, har ökat de senaste årtiondena. En effekt som dessa drar med sig är att de beräknade extremflödena förväntas öka vilket påverkar säkerheten hos befintliga dammar. Flödesdimensioneringsriktlinjerna, vilket kortfattat är riktlinjer för att bestämma dimensionerande flödet i Sverige, reviderades 2015 till att också ta hänsyn till ett föränderligt klimat. Detta leder till krav på befintliga dammar att öka sin avbördningskapacitet samtidigt som intresset för mindre traditionella utskovsanordningar ökar för att säkerställa tillförlitligheten hos utskoven. Denna studie är en fallstudie över en dammanläggning i mellersta Norrland som på grund av en förhöjd klassificering måste öka sin avbördningskapacitet. Syftet med studien är att föreslå åtgärder på dammen som leder till att avbördningskapaciteten blir i linje med flödesdimensioneringsriktlinjerna och att denna rapport ska kunna användas som stöd och underlag när andra dammar i Sverige har motsvarande utmaning. Åtgärderna togs fram genom att först identifiera möjliga utskovsanordningar med avseende på dammens konstruktions- och geologiska förutsättningar samt driftaspekter i ett svenskt klimat. De fördelaktiga utskovsanordningarna anpassades för den aktuella dammanläggningen och avbördningsberäkningar för möjlig design av utskoven utfördes. De åtgärder som kunde avbörda flöden enligt flödesdimensioneringsriktlinjerna utvärderades med avseende på stabilitet i de fall som ansetts möjliga. Efter en diskussion kring olika för-och nackdelar med de olika åtgärderna, med avseende på bland annat ekonomi, föreslogs möjliga lösningar. De utskovsanordningar som enligt resultatet var fördelaktiga att implementera för dammanläggningen var överfallsutskov, både kontrollerat och okontrollerat, och labyrintutskov. Avbördnings-och stabilitetsberäkningarna samt diskussionen kring för och nackdelar kring åtgärderna ledde fram till att tre åtgärder kunde föreslås. Alla tre alternativen innefattade ytvattenutskov, även kallade överfallsutskov med lucka, och var antingen att bygga om befintliga utskov, bygga till ett ytterligare utskov eller en kombination av de två. Labyrintutskovet visade sig ha ganska hög kapacitet, men uppfyllde inte kravet om klass II-flöde vid dämningsgräns. En generell slutsats som kunde dras av studien var att det finns ganska många olika alternativ på utskovsanordningar, men problem och osäkerheter med igenfrysning, drivgods och kavitation måste kunna hanteras i Svenskt klimat. Okontrollerade utskov kan vara ett alternativ, och då främst labyrintutskov, men det förutsätter att dammen med befintlig avbördningskapacitet kan avbörda klass II-flöde.

  • 2386.
    Ahlberg, Fanny
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Ivansen, Anders
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Analys över variationer i vattenförbrukning och dess påverkandefaktorer: En fallstudie över områden i Borås2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The steady supply of fresh water is, and has always been, one of the most important functions in human societies. Different users have been able to take advantage of this resource in different extents and for different purposes. The major areas for water usage are drinking water, water supply for industrial purposes and the usage in agricultural sector.

    By dimensioning the supply- and sewer systems accordingly to the demand of the users a more sustainable and optimal system can be achieved. A proper dimensioning has six general factors it should to take in consideration. These are the size of the population, water consumption in residents, general water consumption in schools and offices, water consumption in industry, leakage and different water losses. With a background of these factors this reports main focus and purpose is analysing the variation in water consumption for different consumers (such as residential houses or apartment blocks) in different time intervals (in this report during days and years) and in respect to different factors. The factors that has been chosen to be examined is how water consumption depends on mean age of the consumers and the outdoor temperature. To complete this study water consumption data of different areas in Borås has been provided from the Swedish consultant firm Tyréns. Before analysing the data another study was made by Victor Eliasson, which included the revealing of different faults in the provided data. As a result of this study the most reliable data was chosen to further analysis with respect to the chosen aspects. During the project the calculation- and modelling program Matlab was used alongside the chart program excel. These two programs combined made it possible to handle large amounts of data and present it in different graphs and models. Conclusions could later be made by analyses and different statistical methods. The result from the comparison between areas with different mean ages of the residents showed that the area with high mean age (80 years) hade a higher water consumption than the other areas. The variation in water consumption differed as well between the area with the high mean age compared to the other areas. A regression- and correlation analysis between water consumption and temperature was performed to see if water consumption is depending on the outdoor temperature. The function of a regression analysis is to describe the relation between different parameters with a mathematic model (in this study a linear model). A correlation analysis is then performed to tell how well the mathematic model describes the relation. A conclusion could be made that the water consumption tends to increase with increasing temperature during parts of the year, since a correlation could be found during mars to September. The strongest correlation was in general during May and July for all the areas. No conclusion of how the variation i water consumption depends on different consumers could be made for the analysis during a day and a year. In contrast to the parameters that had a correlation with water consumption there was no visible connection between water consumption over a year or day depending on different users. 

  • 2387. Ahlberg, J
    et al.
    Claesson, L
    Nauwelarts de Agé, M
    Näsman, P
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Relationen mellan upplevelsemått och fysiologiska mått på fysisk ansträngning1980In: Information från Psykotekniska institutet, ISSN 0347-2795, no 115Article in journal (Other academic)
  • 2388.
    Ahlberg, Jesper
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Modelling of Ice Storms and their Impact on a part of the Swedish Transmission Network2006Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this master thesis a weather model to simulate an ice storm is developed. Precipitation, wind and movement are modelled by mathematical functions to create a realistic model.

    The weather model is used to calculate wind and ice loads on power lines. Two dierent models for the ice accretion on the power lines are used and compared. Data from two storms in Sweden in 1995 and 1999 are studied. In the simulations, the precipitation is assumed to fall as freezing rain instead of snow. The ice and wind loads are calculated in detail for two power lines in southern Sweden. The calculated loads are compared to what is assumed to be the critical loads for the poles, and the risks of power outages in connection with these storms are discussed.

  • 2389.
    Ahlberg, Jesper
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Andrén, Andreas
    KTH, School of Information and Communication Technology (ICT).
    Usability Optimization and Testing Of Social Music Service2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Music playback in venues is very often controlled by the small group of people administrating the business or locale, and not by the audience of listeners themselves. The people listening rarely have any ability to affect the choice of music within the public place or business they are currently situated in.

    This master thesis is built around a developed social music service, that lets the listeners control the playback of music together. The project is called: Blicko, and it enables its users to collaboratively build up a playlist of music, and then vote on the order of the upcoming tracks to be played. It can be thought of as a tool which has similar functions to a jukebox. The service enables the visitors or attendees at any type of public place or venue (i.e. cafes, bars, lobby, restaurants etc.) to be a part of deciding and controlling which music is being played. The thesis is dedicated to examine the best way of refining the service, in terms of optimizing the User Experience (UX), by application of different practices and methods within the field of Human-Computer Interaction (HCI). This also involves managing the complications that rises when developing a multi-platform service for a wide range of devices.

  • 2390.
    Ahlberg, Jesper
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Gustafsson, David
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Distributed snow modelling integrating ground penetrating radar data for improved runoff predictions in a Swedish mountain basin2009In: EGU General Assembly 2009, 2009Conference paper (Other academic)
    Abstract [en]

    Operational forecasts of snow melt runoff in Sweden are currently running with precipitation and temperature as the main input variables and calibrated with runoff data, and there is an interest to make better use of new measurement systems for distributed snow data. At the same time, various data assimilation techniques are becoming more frequently used in hydrological modeling, in order to reduce uncertainties related to both model structure errors and errors in input and calibration data. Thus, it is important to address not only what type of snow data that can be used to improve the model predictions, but also what type of input data and model structures that are optimal in relation to the available snow data. The objective of this study is to investigate to what extent the runoff predictions can be improved by assimilation of temporal and spatially distributed snow data, and if the improvements depend on the choice of model structures, for instance the use of energy balance or day-degree snow models. In order to achieve these objectives a new distributed snow model has been implemented into the hydrological modeling framework HYSS/HYPE. This model can easily be setup with either an energy balance model or a day-degree model for the snow pack calculations, and it is easy to run the model with different spatial resolutions. In the fully distributed case, snow drift processes are implicitly included in the model through a precipitation distribution model, based on topographical information and wind direction. The model was applied to a mountain basin in northern Sweden used for hydropower production, where extensive snow measurements were taken during the last two winters 2007-2009. A climate station is located at the outlet of the regulation lake, including automated point measurements of snow depth, snow mass (snow pillow), snow wetness and snow temperature. Distributed snow cover data was sampled using ground-penetrating radar from snow mobiles. Measurements were taken at the time of the maximum snow cover, providing a data set with snow depth, snow density, snow water equivalent along 20 km long transects in representative areas of the basin. The precipitation distribution model was calibrated using the distributed SWE data from the GPR measurements. Application of the calibrated model to previous years without available snow data show that the runoff predictions was improved compared to calibrations without the distributed snow data, however the improvements were larger for the energy balance compared to the day-degree model. Further developments will include assimilation of the temporal and spatial snow data to adjust the distribution of various input variables, for instance air temperature and wind speed.

  • 2391.
    Ahlberg, Jesper
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Gustafsson, David
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Snow melt runoff simulations using ensemble Kalman filter assimilation of distributed snow data2010Conference paper (Other academic)
  • 2392.
    Ahlberg, Johan
    KTH, School of Technology and Health (STH).
    Real life analysis of myoelectric pattern recognition using continuous monitoring2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of non-invasive signal acquisition methods is today the standard for testing pattern recognition algorithms in prosthetic control. Such research had shown consecutively high performance on both prerecorded and real time data, yet when tested in real life they deteriorate.

    To investigate why, the author who is a congenital amputee, wore a prosthetic system utilizing pattern recognition control on a daily basis for a five-day period. The system generated one new classification every 50 ms and movement execution was made continuously; for classifying open/close; and by winning a majority vote; for classifying side grip, fine grip and pointer. System data was continuously collected and errors were registered through both a manual and an automatic log system.

    Calculations on extracted data show that grip classifications had an individual accuracy of 47%- 70% while open/close got 95%/98%, but if classified according to a majority vote, grips increased their accuracy to above 90% while open/close dropped to 80%. The conclusion was that majority vote might help complex classifications, like fine grips, while simpler proportional movements is exacerbated by majority voting. Major error sources were identified as signal similarities, electrode displacements and socket design.

    After the daily monitoring ended the systems functionality was tested using the "Assessment of Capacity for Myoelectric Control". The ACMC results showed that the system has similar functionality to commercial threshold control and thus is a possible viable option for both acquired and congenital amputees.

  • 2393.
    Ahlberg, Johan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Jansson, Anton
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Corporate Hybrid Bonds2016Independent thesis Advanced level (degree of Master (Two Years)), 20 HE creditsStudent thesis
    Abstract [en]

    Hybrid securities do not constitute a new phenomenon in the Swedish capital markets. Most commonly, hybrids issued by Swedish real estate companies in recent years are preference shares. Corporate hybrid bonds on the other hand may be considered as somewhat of a new-born child in the family of hybrid instruments. These do, as all other hybrid securities, share some equity-like and some debt-like characteristics. Nevertheless, since 2013 the interest for the instrument has grown rapidly and has become a well-accepted, as well as a fairly standardized, source of financing for many well-established corporations around the world. Yet, we have seen very few issues in Sweden and no issues by Swedish real estate companies.

    Corporate hybrid bonds could in a rather simplified manner be explained as a subordinated bond with some equity characteristics. Examples of such equity characteristics are perpetual maturity (or at least very long), coupon deferability and the fact that it due to its subordination provides significant loss absorption. Yet, it also holds typical debt-like characteristics such as regular coupon payments and seniority to equity.

    The outcome of this research has shown that issuing corporate hybrid bonds could be beneficial to a firm. Coupon payments are, unlike dividend payments to holders of preference shares but alike interest payments on a standard bank loan, tax deductible. Other probable advantages with corporate hybrid bonds are; a stronger credit profile (which potentially could improve the (shadow)credit-rating and thus also the terms of other sources of finance), a diversified investment base as well as diversification from a capital structure perspective.

    However, despite the many advantages, numerous obstacles remain. The main shortcoming highlighted among potential issuers is the high pricing of the instrument in relation to other alternatives. Moreover, the lack of Swedish investors investing in hybrid bonds, the assumingly poor liquidity of the product along with the high denomination (piece price) due to regulatory legislations make up for topics of concern among both potential investors and issuers. Although, considering the many benefits, we believe that the weaknesses can be overseen and that there is a potential future use for the product in event of further expansion and acquisition or if the access to capital markets is limited. After all, all good things take time.

  • 2394.
    Ahlberg, Johan
    et al.
    KTH, School of Technology and Health (STH).
    Wang, Jie Yu
    KTH, School of Technology and Health (STH).
    Utveckling av en teoretisk elektrokemisk apparatur för vattentransport i hjärnvävnad2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Every year in Sweden there is about 24,000 head injuries due to external trauma and 30,000 strokes. A significant number may develop secondary damage because of the increased water content around the damaged brain tissue. The proposed method is to induce water flow from damaged to healthy tissue based on the theory of electroosmosis. The theory behind the electroosmosis is that a flow is induced when a voltage is applied across a medium. The theory of electroosmosis is applied in industry and called electro-osmotic dewatering (EOD) which is used as a drying technique for the dewatering of bio-materials, clays, tofu sheets and electroosmosis is also applied in clinical treatment of tumors. Several experiments were performed on brain phantoms consisting of agarose gel to examine whether the method can be used to divert water. The first experiment was done prove that a flow can be induced when a voltage is applied over the phantom. The second experiment was to investigate the relationship between the flow rate, voltage and current. The result showed linear correlation between flow rate and voltage, flow rate and current, and between the voltage and current. The literature sources and experimental results were referred to a relationship which is developed to determine the flow induced by electrical field. The work was completed with recommendations in electrode material, design and placement. The recommendations are to use plate electrodes at a current density under 25 mA/m2. Electrode placement is predetermined by Finite Element (FE) simulations of different types of injuries.

  • 2395. Ahlberg, M.
    et al.
    Lindmark, B.
    Simons, J.
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth. KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Downlink propagation measurements in the GSM 900 and 1800 MHz bands1999In: IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010), 1999, Vol. 3, p. 1506-1509 vol.3Conference paper (Refereed)
    Abstract [en]

    The authors investigate radio propagation in the GSM 900 and 1800 MHz bands in a typical Swedish suburban environment to determine whether or not it is practically feasible to co-site GSM 900 with GSM 1800 systems. They show that propagation in the GSM 1800 band is considerable higher (about 12 dB) than in the old GSM 900. In many cases this difference can be reduced by using dual band sector antennas with 3 dB higher gain at 1800 MHz. However, they also show that in small cells (radius <1000 m) this difference is of little concern and therefore it is possible to co-locate GSM 1800 sites within existing 900 MHz sites as a cost-effective way to increase the system capacity.

  • 2396.
    Ahlberg, Marcus
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Fornander, Eric
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Test Case Prioritization as a Mathematical Scheduling Problem2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Software testing is an extremely important phase of product development where the objective is to detect hidden bugs. The usually high complexity of today’s products makes the testing very resource intensive since numerous test cases have to be generated in order to detect all potential faults. Therefore, improved strategies of the testing process is of high interest for many companies. One area where there exists potential for improvement is the order by which test cases are executed to detect faults as quickly as possible, which in research is known as the test case prioritization problem. In this thesis, an extension to this problem is studied where dependencies between test cases are present and the processing times of the test cases are known. As a first result of the thesis, a mathematical model of the test case prioritization problem with dependencies and known processing times as a mathematical scheduling problem is presented. Three different solution algorithms to this problem are subsequently evaluated: A Sidney decomposition algorithm, an own-designed heuristic algorithm and an algorithm based on Smith’s rule. The Sidney decomposition algorithm outper-formed the others in terms of execution time of the algorithm and objective value of the generated schedule. The evaluation was conducted by simulation with artificial test suites and via a case study in industry through a company in the railway domain.

  • 2397.
    Ahlberg, Marcus
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Lilja, Jimmy
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Lageroptimering: Minimera tiden till leverans med begränsat lagerutrymme2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis presents a study in mathematical optimization of the inventory routine at the company Aktiebolaget Kronborsten. The thesis establishes a general optimization problem identified at Kronborstens inventory routine. The identified problem is to find the optimal mix between products in the finished goods inventory, which minimizes the expected time until delivery.

    The proposed model assumes that orders and manufacturing follow a stochastic process. With these assumptions the inventory and manufacturing are represented as several independent Markov processes. From the stationary distribution of these processes a function was identified for the expected time until delivery for a given solution. The identified function had convex properties which made it possible to solve the optimization problem using the marginal allocation algorithm.

    The mathematical problem is followed by a chapter about the costs related to storage. The purpose of this chapter is to help Kronborsten to valuate their options and consequences of strategical decisions about the inventory levels. 

  • 2398.
    Ahlberg, Michael
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Yasui, Terumasa
    Advanced Technology Research and Development Center, Mitsubishi Electric Corporation, Amagasaki, Japan.
    Router placement in wireless sensor networks2006In: 2006 IEEE International Conference on Mobile Adhoc and Sensor Systems, Vols 1 and 2, IEEE , 2006, p. 498-501Conference paper (Refereed)
    Abstract [en]

    In this paper we propose and evaluate algorithms for placement of routers in a wireless sensor network. There are two major requirements on router placement First, a placement must guarantee connectivity, i.e. every sensor must be able to communicate through routers with a predefined computer-connected gateway node. Second, a placement must provide robust communication in the case of router failures. This is achieved by placing redundant routers that increase the number of possible routes. Both requirements should be met by placing as few routers as possible. The proposed algorithms compute placement in an efficient and reasonably fast way.

  • 2399. Ahlberg, P.
    et al.
    Karlsson, A.
    Goeppert, A.
    Lill, S. O. N.
    Dinér, Peter
    Sommer, J.
    Solvated CH5+ in liquid superacid2001In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 7, no 12, p. 2501-2510Article in journal (Refereed)
  • 2400. Ahlberg, Simon
    et al.
    Horling, Pontus
    Johansson, Katarina
    Jored, Karsten
    Kjellström, Hedvig
    Martenson, Christian
    Neider, Gbran
    Schubert, Johan
    Svenson, Pontus
    Svensson, Per
    Walter, Johan
    An information fusion demonstrator for tactical intelligence processing in network-based defense2007In: Information Fusion, ISSN 1566-2535, E-ISSN 1872-6305, Vol. 8, no 1, p. 84-107Article in journal (Refereed)
    Abstract [en]

    The Swedish Defence Research Agency (FOI) has developed a concept demonstrator called the Information Fusion Demonstrator 2003 (IFD03) for demonstrating information fusion methodology suitable for a future Network Based Defense (NBD) C4ISR system. The focus of the demonstrator is on real-time tactical intelligence processing at the division level in a ground warfare scenario. The demonstrator integrates novel force aggregation, particle filtering, and sensor allocation methods to create, dynamically update, and maintain components of a tactical situation picture. This is achieved by fusing physically modelled and numerically simulated sensor reports from several different sensor types with realistic a priori information sampled from both a high-resolution terrain model and an enemy organizational and behavioral model. This represents a key step toward the goal of creating in real time a dynamic, high fidelity representation of a moving battalion-sized organization, based on sensor data as well as a priori intelligence and terrain information, employing fusion, tracking, aggregation, and resource allocation methods all built on well-founded theories of uncertainty. The motives behind this project, the fusion methods developed for the system, as well as its scenario model and simulator architecture are described. The main services of the demonstrator are discussed and early experience from using the system is shared.

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