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  • 251.
    Abrahamsson, Lars
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Östlund, Stefan
    KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.
    Söder, Lennart
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    HVDC feeding with OPF and unit commitment for electric railways2012In: Electrical Systems for Aircraft, Railway and Ship Propulsion (ESARS), 2012, IEEE , 2012, p. 6387481-Conference paper (Refereed)
    Abstract [en]

    In this paper a railway power system design based on an HVDC feeder is suggested. The converter stations between the public grid and the HVDC feeder can be sparsely distributed, in the range of 100 km or more, whereas the converters connecting the HVDC feeder to the catenary are distributed with a much closer spacing. The ratings of the catenary-connected ones can be lower than substation transformers or rotary converters, since the power conversion can be fully controlled. Simulations of the proposed solution show clear advantages regarding transmission losses and voltages compared to conventional systems, especially for cases with long catenary sections, and when there are substantial shares of regeneration from the trains.

  • 252.
    Abrahamsson, Lars
    et al.
    KTH, Superseded Departments, Electric Power Systems.
    Östlund, Stefan
    KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.
    Söder, Lennart
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Optimal PowerFlow (OPF) Model with Unified AC-DC Load Flow and Optimal Commitmentfor an AC-catenary Railway Power Supply System (RPSS) fed by aHigh Voltage DC (HVDC) transmission lineManuscript (preprint) (Other academic)
    Abstract [en]

    In this paper an alternative railway power systems design based on an HVDC feeder is studied. The HVDC feeder is connected to the catenary by converters. Such an HVDC line is also appropriate for DC-fed railways and AC-fed railways working at public frequency.

    A unit commitment optimal power flow model has been developed and is applied on a test system. In this paper, the model is presented in detail. The model, in the form of an MINLP program, uses unified AC-DC power flow to minimize the entire railway power system losses.

    Simulations of the proposed solution show clear advantages regarding transmission losses and voltages compared to conventional systems, especially for cases with long distances between feeding points to the catenary, and when there are substantial amounts of regeneration from the trains.

  • 253.
    Abrahamsson, Lars
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Östlund, Stefan
    KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.
    Söder, Lennart
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Optimal PowerFlow (OPF) Model with Unified AC-DC Load Flow and Optimal Commitmentfor an AC-catenary Railway Power Supply System (RPSS) fed by aHigh Voltage DC (HVDC) transmission line2012Article in journal (Refereed)
    Abstract [en]

    In this paper an alternative railway power systems design based on an HVDC feeder is studied. The HVDC feeder is connected to the catenary by converters. Such an HVDC line is also appropriate for DC-fed railways and AC-fed railways working at public frequency. A unit commitment optimal power flow model has been developed and is applied on a test system. In this paper, the model is presented in detail. The model, in the form of an MINLP program, uses unified AC-DC power flow to minimize the entire railway power system losses. Simulations of the proposed solution show clear advantages regarding transmission losses and voltages compared to conventional systems, especially for cases with long distances between feeding points to the catenary, and when there are substantial amounts of regeneration from the trains.

  • 254.
    Abrahamsson, Magnus
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Optimering av bergtransporter i underjordsgruva2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis project was conducted at LKAB, a mineral group that manufactures and supplies iron ore products. The work was conducted for the company's underground mine in Malmberget and deals with the rock transport from the mine development. Development is the process which prepares new parts of the mine for iron ore mining. The goals of this work was to identify how the rock transport from the mine development is controlled and to quantify potential savings. If possible, improvement suggestions were to be presented. The basis for this study has been collected on the site of the mine in Malmberget through meetings and conversations with staff, own observations and review of internal documents. Details of the rock transport from the mine development have also been collected in the form of freight statistics and price information. To achieve the goals of the study, two different approaches were chosen. To identify how the transport of rock from the mine development is controlled, a process mapping effort was performed. To quantify the potential savings, I have sought the lowest possible transport cost and compared this with the actual outcome. The study shows that there is a gross potential to reduce transportation costs by 3060 kSEK per halfyear, corresponding to approximately 20 % of the total transport cost. Of this amount, underground transports account for 2041 kSEK (13 %) and transports out of the mine account for 1019 kSEK (6 %). However, the study's limitations makes the potential savings for transports out of the mine highly uncertain. If shafts are made available already in the development stage, there will be even further opportunities to reduce costs.

  • 255. Abrahamsson, S.
    et al.
    Blom, Hans
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Agostinho, A.
    Jans, Daniel
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Jost, A.
    Müller, M.
    Nilsson, Linnea
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Bernhem, K.
    Lambert, T. J.
    Heintzmann, R.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Multifocus structured illumination microscopy for fast volumetric super-resolution imaging2017In: Biomedical Optics Express, ISSN 2156-7085, E-ISSN 2156-7085, Vol. 8, no 9, p. 4135-4140, article id #294866Article in journal (Refereed)
    Abstract [en]

    We here report for the first time the synergistic implementation of structured illumination microscopy (SIM) and multifocus microscopy (MFM). This imaging modality is designed to alleviate the problem of insufficient volumetric acquisition speed in superresolution biological imaging. SIM is a wide-field super-resolution technique that allows imaging with visible light beyond the classical diffraction limit. Employing multifocus diffractive optics we obtain simultaneous wide-field 3D imaging capability in the SIM acquisition sequence, improving volumetric acquisition speed by an order of magnitude. Imaging performance is demonstrated on biological specimens.

  • 256.
    Abrahamsson, Sara
    KTH, School of Chemical Science and Engineering (CHE).
    Reduktion av organiskt material med MIEX®2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The lake Mälaren is the main source of drinking water in Stockholm and Uppsala. The concentration of organic carbon varies from year to year in Mälaren and may affect, during the water purification, the drinking water resulting undesirable smell, taste and color. Another part of the problem is formation of disinfection byproducts (DPB) and transportation of toxic substances. The concentration of organic carbon in Mälaren will probably increase due to issues such as global warming. Increasing concentration of organic carbon results in harder difficulties for purification in water treatment facilities. Therefore accurate water treatment processes have to be developed considered the higher future treatment demand. A promising alternative is the anion exchange process called MIEX® (Magnetic Ion Exchange resin process) which is a process for water containing dissolved organic materials.

     

    The purpose of the project was to investigate MIEX® treatment for removal of dissolved organic matter (DOC). The aim was to find an optimal contact time and the right number of bed volumes for treatments in a water treatment facility. The aim also involved an evaluation of selectivity for fluorescence and UV-absorbing (254 nm) groups of DOC.  

     

    The main conclusions of the project are that a contact time of 15 minutes and 400-1000 bed volumes should be treated in a water treatment facility. MIEX® seems to be selective for terrestrial and humified material of DOC as well as aromatic groups of DOC.

  • 257.
    Abrahamssson Kwetczer, Loise
    et al.
    KTH, School of Engineering Sciences (SCI).
    Stigenberg, Jakob
    KTH, School of Engineering Sciences (SCI).
    Mobile Network trafficprediction: Based on machine learning2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The investing market can be a cold ruthless placefor the layman. In order to get the chance of making money inthis business one must place countless hours on research, withmany different parameters to handle in order to reach success.To reduce the risk, one must look to many different companiesoperating in multiple fields and industries. In other words, it canbe a hard task to manage this feat.With modern technology, there is now lots of potential tohandle this tedious analysis autonomously using machine learningand clever algorithms. With this approach, the amount ofanalyzes is only limited by the capacity of the computer. Resultingin a number far greater than if done by hand.This study aims at exploring the possibilities to modify andimplement efficient algorithms in the field of finance. The studyutilizes the power of kernel methods in order to algorithmicallyanalyze the patterns found in financial data efficiently. Bycombining the powerful tools of change point detection andnonlinear regression the computer can classify the differenttrends and moods in the market.The study culminates to a tool for analyzing data from thestock market in a way that minimizes the influence from shortspikes and drops, and instead is influenced by the underlying pattern.But also, an additional tool for predicting future movementsin the price.

  • 258.
    Abramczuk, Monika
    KTH, School of Biotechnology (BIO).
    Isolation and characterization of the first heart field progenitor cells2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 259.
    Abramson, Nils
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Holography, relativity and the spooky ellipsoids2006In: Proceedings of the 7th International Symposium on Display Holography: Advances In Display Holography / [ed] Bjelkhagen, HI, 2006, p. 228-235Conference paper (Refereed)
    Abstract [en]

    The further away from a house we move, the smaller it appears. We could say that we are in the centre of a "sphere of observation", which must reach the house before we can see it. The larger that sphere is, the smaller the house appears. This is natural to us and not difficult to understand. In Einstein's Special Relativity it is stated that the faster we move past a house, the shorter it appears. We state in this paper that this is because the faster we travel, the more our "sphere of observation" is elongated into an "ellipsoid of observation". The longer that ellipsoid is, the shorter the house appears. This contraction is not so natural to us, because to be observable the velocity has to be extremely high, almost close to the velocity of light. A similar phenomenon can, however, be studied when holography with ultrashort pulses is used for measurement. In this case the sphere of observation is also transformed into an ellipsoid of observation. Thus, according to our approach objects appear shorter because the definition of length (the metre) becomes longer, just as time moves slower because the definition of time (the second) becomes longer. The transformation of the sphere into an ellipsoid is however hidden to the observer both in the case of holography and in relativity. This spooky behaviour of the ellipsoid has resulted in a new mathematical theorem.

  • 260.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Lorentz contraction, apparent or real2013In: Progress In Electromagnetics Research Symposium Proceedings, Stockholm, Sweden, Aug. 12-15, 2013, 2013, p. 1547-1549Conference paper (Refereed)
    Abstract [en]

    The Michelson Morley interference experiment of 1887 indicated that the velocity of light is independent of the velocities of source and observer. This surprising result was in conflict with earlier calculations. To make theory and experiment in agreement Lorentz stated a contraction of rigid objects parallel to velocity. We discuss if this contraction is real or caused by the interference method of measurement. Our approach is to introduce a sphere of observation based on ultra short light pulses combined to ultra short observations. When the experimenter travels at high velocity this sphere is according to Lorentz contracted into an oblate ellipsoid. According to our proposed theory the sphere is instead elongated into a prolate ellipsoid. The result of this effect is that stationary objects appear contracted. Our results are in full agreement to Einsteins Special Theory of Relativity. To support our statements we introduce a novel method to measure the length of a travelling object that is independent of interferometry.

  • 261.
    Abramsson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Brygiewicz, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Partnering - Kundnytta i fokus2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The literature and research is limited in the subject costumer value in partnering projects. This contributed to the interest to perform an empirical study on the topic. It has not been shown to be appropriate to implement this on a specific issue or problem, when the available information deals with the theory and applications of partnering, not customer value.

    Given the above problem this papers purpose is to describe how the various contractors and clients, associated with partnering activities in Sweden, experiencing the work and factors that maximize customer value in a partnering project.

    A qualitative method where six people were interviewed, related to partnering activities in Sweden. The interviews are semi-structured and adapted to each interviewee.

    The most important conclusions that answer the purpose are:

     Understand the customers business

     Choose a form of compensation based on founded trust and project type

     All parties combined knowledge provides the right conditions for the customer to make the right decision

     Lack of common well-developed digital tools

     Make decisions at the right time

     Reference Surfaces and own final checks instead third party inspector

  • 262. Abrardo, A.
    et al.
    Belleschi, M.
    Fodor, Gábor
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Moretti, M.
    A message passing approach for resource allocation in cellular OFDMA communications2012In: Global Communications Conference (GLOBECOM), 2012 IEEE, IEEE , 2012, p. 4583-4588Conference paper (Refereed)
    Abstract [en]

    This paper proposes a distributed and low-complexity resource allocation scheme for cellular OFDMA networks. In particular, we consider ReMP, a reweighted message passing algorithm that perturbs the standard max-sum algorithm by suitably reweighting messages. In a single-cell scenario, such a scheme allows to achieve convergence to a fixed and provably optimum point without employing any central controller. The ReMP algorithm is then adapted to a multi-cell environment. To this aim, we devise X-ReMP, a ReMP-based algorithm that combines cross-cell signaling and the regular ReMP routine that still runs within each cell. The cross-signaling among cells aids ReMP to deal with the inter-cell multiple-access interference, so that X-ReMP allows convergence to a good working point in terms of system throughput even in presence of strong inter-cell interference.

  • 263. Abrardo, A
    et al.
    Fodor, G
    Tola, B
    Network coding schemes for D2D communications based relaying for cellular coverage extension2015In: European transactions on telecommunications, ISSN 1124-318X, E-ISSN 2161-3915, Vol. -Article in journal (Refereed)
    Abstract [en]

    Although network-assisted device-to-device (D2D) communications are known to improve the spectral and energy efficiency of proximal communications, the performance of cooperative D2D schemes in licenced spectrum is less understood when employed to extend the coverage of cellular networks. In this paper, we study the performance of D2D-based range extension in terms of sum rate and power efficiency when a relaying user equipment (UE) helps to improve the coverage for cell edge UEs. In our design, the relaying UE may have own traffic to transmit and receive to/from the cellular base station (BS) and can operate either in amplify-and-forward (AF) or decode-and-forward (DF) modes and can make use of either digital or analogue physical (PHY) layer network coding. In this rather general setting, we propose mode selection, resource allocation and power control schemes and study their performance by means of system simulations. We find that the performance of the DF scheme with network coding is superior both to the traditional cellular and the AF-based relaying schemes, including AF with two-slot or three-slot PHY layer network coding.

  • 264. Abrardo, A
    et al.
    Fodor, Gabor
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Tola, B.
    Network coding schemes for Device-To-Device communications based relaying for cellular coverage extension2015In: IEEE Workshop on Signal Processing Advances in Wireless Communications, SPAWC, 2015, p. 670-674Conference paper (Refereed)
    Abstract [en]

    In this paper, we study the performance of device-To-device (D2D) based range extension in terms of sum rate and power efficiency when a relaying user equipment (UE) helps to improve the coverage for cell-edge UEs. In our design, the relaying UE has own traffic to transmit and receive to/from the cellular base station (BS) and can operate either in amplify-And-forward (AF) or decode-And-forward (DF) modes and can make use of either digital or analogue (PHY layer) network coding. In this rather general setting, we propose mode selection, resource allocation and power control schemes and study their performance by means of system simulations. We find that the performance of the DF scheme with network coding is superior both to the traditional cellular and the AF based relaying schemes, including AF with two-slot or three-slot PHY layer network coding.

  • 265.
    Abrardo, Andrea
    et al.
    University of Siena, Italy.
    Fodor, Gabor
    KTH, School of Electrical Engineering (EES), Automatic Control. Ericsson Research, Stockholm.
    Tola, Besmir
    University of Siena, Italy.
    Network Coding Schemes for Device-to-Device Communications Based Relaying for Cellular Coverage Extension2015Report (Other academic)
    Abstract [en]

    Although network assisted device-to-device (D2D) communications is known to improve the spectraland energy efficiency of proximal communications, its performance is less understood when employedto extend the coverage of cellular networks.In this paper, we study the performance of D2D basedrange extension in terms of sum rate and power efficiency when a relaying user equipment (UE) helps to improvethe coverage for cell-edge UEs.In our design, the relaying UE has own traffic to transmit and receive to/from the cellular base station (BS) andcan operate either in amplify-and-forward (AF) or decode-and-forward (DF) modes and can make use of either digital oranalogue (PHY layer) network coding.In this rather general setting, we propose mode selection, resource allocation and power control schemesand study their performance by means of system simulations.We find that the performance of the DF scheme with network coding is superior both to the traditional cellularand the AF based relaying schemes, including AF with two-slot or three-slot PHY layer network coding.

  • 266.
    Abrehdary, Majid
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Recovering Moho parameters using gravimetric and seismic data2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Isostasy is a key concept in geoscience to interpret the state of mass balance between the Earth’s crust and mantle. There are four well-known isostatic models: the classical models of Airy/Heiskanen (A/H), Pratt/Hayford (P/H), and Vening Meinesz (VM) and the modern model of Vening Meinesz-Moritz (VMM). The first three models assume a local and regional isostatic compensation, whereas the latter one supposes a global isostatic compensation scheme.

    A more satisfactory test of isostasy is to determine the Moho interface. The Moho discontinuity (or Moho) is the surface, which marks the boundary between the Earth’s crust and upper mantle. Generally, the Moho interface can be mapped accurately by seismic observations, but limited coverage of seismic data and economic considerations make gravimetric or combined gravimetric-seismic methods a more realistic technique for imaging the Moho interface either regional or global scales.

    It is the main purpose of this dissertation to investigate an isostatic model with respect to its feasibility to use in recovering the Moho parameters (i.e. Moho depth and Moho density contrast). The study is mostly limited to the VMM model and to the combined approach on regional and global scales. The thesis briefly includes various investigations with the following specific subjects:

    1) to investigate the applicability and quality of satellite altimetry data (i.e. marine gravity data) in Moho determination over the oceans using the VMM model, 2) to investigate the need for methodologies using gravimetric data jointly with seismic data (i.e. combined approach) to estimate both the Moho depth and Moho density contrast over regional and global scales, 3) to investigate the spherical terrain correction and its effect on the VMM Moho determination, 4) to investigate the residual isostatic topography (RIT, i.e. difference between actual topography and isostatic topography) and its effect in the VMM Moho estimation, 5) to investigate the application of the lithospheric thermal-pressure correction and its effect on the Moho geometry using the VMM model, 6) Finally, the thesis ends with the application of the classical isostatic models for predicting the geoid height.

    The main input data used in the VMM model for a Moho recovery is the gravity anomaly/disturbance corrected for the gravitational contributions of mass density variation due in different layers of the Earth’s crust (i.e. stripping gravity corrections) and for the gravity contribution from deeper masses below the crust (i.e. non-isostatic effects). The corrections are computed using the recent seismic crustal model CRUST1.0.

    Our numerical investigations presented in this thesis demonstrate that 1) the VMM approach is applicable for estimating Moho geometry using a global marine gravity field derived by satellite altimetry and that the possible mean dynamic topography in the marine gravity model does not significantly affect the Moho determination, 2) the combined approach could help in filling-in the gaps in the seismic models and it also provides good fit to other global and regional models more than 90 per cent of the locations, 3) despite the fact that the lateral variation of the crustal depth is rather smooth, the terrain affects the Moho result most significantly in many areas, 4) the application of the RIT correction improves the agreement of our Moho result with some published global Moho models, 5) the application of the lithospheric thermal-pressure correction improves the agreement of VMM Moho model with some other global Moho models, 6) the geoid height cannot be successfully represented by the classical models due to many other gravitational signals from various mass variations within the Earth that affects the geoid.  

  • 267.
    Abrehdary, Majid
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning. Univ Karlstad, Sweden.
    Sjöberg, L. E.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Bagherbandi, Mohammad
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning. Univ Gavle, Sweden.
    Sampietro, D.
    Towards the Moho depth and Moho density contrast along with their uncertainties from seismic and satellite gravity observations2017In: Journal of Applied Geodesy, ISSN 1862-9016, E-ISSN 1862-9024, Vol. 11, no 4, p. 231-247Article in journal (Refereed)
    Abstract [en]

    We present a combined method for estimating a new global Moho model named KTH15C, containing Moho depth and Moho density contrast (or shortly Moho parameters), from a combination of global models of gravity (GOCO05S), topography (DTM2006) and seismic information (CRUST1.0 and MDN07) to a resolution of 1 degrees x 1 degrees based on a solution of Vening Meinesz-Moritz' inverse problem of isostasy. This paper also aims modelling of the observation standard errors propagated from the Vening Meinesz-Moritz and CRUST1.0 models in estimating the uncertainty of the final Moho model. The numerical results yield Moho depths ranging from 6.5 to 70.3 km, and the estimated Moho density contrasts ranging from 21 to 650 kg/m(3), respectively. Moreover, test computations display that in most areas estimated uncertainties in the parameters are less than 3 km and 50 kg/m(3), respectively, but they reach to more significant values under Gulf of Mexico, Chile, Eastern Mediterranean, Timor sea and parts of polar regions. Comparing the Moho depths estimated by KTH15C and those derived by KTH11C, GEMMA2012C, CRUST1.0, KTH14C, CRUST14 and GEMMA1.0 models shows that KTH15C agree fairly well with CRUST1.0 but rather poor with other models. The Moho density contrasts estimated by KTH15C and those of the KTH11C, KTH14C and VMM model agree to 112, 31 and 61 kg/m(3) in RMS. The regional numerical studies show that the RMS differences between KTH15C and Moho depths from seismic information yields fits of 2 to 4 km in South and North America, Africa, Europe, Asia, Australia and Antarctica, respectively.

  • 268.
    Abrehdary, Majid
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Sjöberg, Lars E.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Bagherbandi, Mohammad
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Modelling Moho depth in ocean areas based on satellite altimetry using Vening Meinesz–Moritz’ method2016In: Acta Geodaetica et Geophysica Hungarica, ISSN 1217-8977, E-ISSN 1587-1037, Vol. 51, no 2, p. 137-149Article in journal (Refereed)
    Abstract [en]

    An experiment for estimating Moho depth is carried out based on satellite altimetryand topographic information using the Vening Meinesz–Moritz gravimetric isostatichypothesis. In order to investigate the possibility and quality of satellite altimetry in Mohodetermination, the DNSC08GRA global marine gravity field model and the DTM2006 globaltopography model are used to obtain a global Moho depth model over the oceans with aresolution of 1 x 1 degree. The numerical results show that the estimated Bouguer gravity disturbancevaries from 86 to 767 mGal, with a global average of 747 mGal, and the estimatedMoho depth varies from 3 to 39 km with a global average of 19 km. Comparing the Bouguergravity disturbance estimated from satellite altimetry and that derived by the gravimetricsatellite-only model GOGRA04S shows that the two models agree to 13 mGal in root meansquare (RMS). Similarly, the estimated Moho depths from satellite altimetry andGOGRA04S agree to 0.69 km in RMS. It is also concluded that possible mean dynamictopography in the marine gravity model does not significantly affect the Moho determination.

  • 269.
    Abrehdary, Majid
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Sjöberg, Lars E.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Bagherbandi, Mohammad
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
    Sampietro, Daniele
    Modelling Moho parameters and their uncertainties from the combination of the seismic and satellite gravity dataManuscript (preprint) (Other academic)
    Abstract [en]

    We present a method for estimating a new global Moho model (KTH15C), containing Moho depth and density contrast, from a combination of global models of gravity (GOCO05S), topography (DTM2006) and seismic information (CRUST1.0 and MDN07) to a resolution of 1°×1° based on a solution of Vening Meinesz-Moritz’ inverse problem of isostasy. Particularly, this article has its emphasis on the modelling of the observation standard errors propagated from the Vening Meinesz-Moritz and CRUST1.0 models in estimating the uncertainty of the final Moho model. The numerical results yield Moho depths ranging from 6.5 to 70.1 km, with a global average of 23.4 ± 13 km. The estimated Moho density contrasts range from 21 to 680 kg/m3, with a global average of 345.4 ± 112 kg/m3. Moreover, test computations display that in most areas estimated uncertainties in the parameters are less than 3 km and 50 kg/m3, respectively, but they reach to more significant values under Gulf of Mexico, Chile, Eeastern Mediterranean, Timor sea and parts of polar regions. Comparing the Moho depths estimated by KTH15C and those derived by KTH11C, GEMMA2012C, CRUST1.0, KTH14C, CRUST14 and GEMMA1.0 models shows that KTH15C agree fairly well with CRUST1.0 but rather poor with other models. The Moho density contrasts estimated by KTH15C and those of the KTH11C and KTH14C model agree to 120 and 80 kg/m3 in RMS. The regional numerical studies show that the RMS differences between KTH15C and Moho depths from seismic information yields fits of 2 to 4 km in South and North America, Africa, Europe, Asia, Australia and Antarctica, respectively.    

  • 270.
    Abrigian, Mari
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Almqvist Gärtner, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Möjligheter och utmaningar med internationella inköp: En studie av internationella inköp2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The construction industry in Sweden today are facing a major challenge in building society and following the pace of population growth. Rising material prices are today a fact, and at the same time there is a lack of capacity at the Swedish suppliers as they are bound up in supplier agreements for the coming years. The largest construction companies in Sweden have been working strategically with international suppliers for a long time to increase their margins and to secure their material needs.

    BTH Bygg AB is today a company that builds, renovates and maintains real estate in Stockholm. The company has expanded in recent years and is committed to strong growth by 2020. Work on international purchasing has previously been limited to BTH Bygg, but this type of purchase is today seen as a necessity to continued growth and to be competitive in that part of Sweden where most is built.

    The purpose of this study is to analyze BTH Bygg's existing purchasing process to further develop and propose improvements with international procurement as a starting point.

    The study has been conducted with the help of interviews to get a complete picture of the issues of international purchasing. BTH Bygg AB has a strong organization with a lot of experience related to the subject area, and focus has been on compiling these in order to come up with suggestions and ideas on how to handle international purchases. Recommendations are focused on areas related to supplier assessment, communication, logistics and product selection.

  • 271.
    Abshirini, Ehsan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Interaction between rivers and morphology of cities in Sweden2014In: Our common future in urban morphology, Porto: FEUP edições (Faculdade de Engenharia da Universidade do Porto Edicoes), 2014Conference paper (Refereed)
    Abstract [en]

    Rivers as one of the most important topographic factor have played a strategic role not only on the appearance of cities but they also affect the structure and morphology of cities. In this paper I intend to find out the influence of rivers on the morphology of a cities and discuss that how a city in its physical network interacts with a river flowing inside. My study area is river-cities in Sweden in which they have not received much attention in this issue. To this purpose I use space syntax method integrating with geospatial analysis and extract the properties of physical form of cities in terms of global and local integration value, choice value and so on. Comparing the states of presence and absence of rivers in these cities as well as evaluating the effect of rivers on the morphology of areas located in different banks of rivers are also part of interest in this paper. The primary result shows that although a river is not comparable to a city based on size and the area occupied by, it has a significant effect on the form of a city in both global and local properties. In addition, tracking the pattern of river-cities and their interaction to rivers may lead us to interoperate the physical form of these cities in terms of structured and distributed cities.

  • 272.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture, Architectural Design.
    Resilience, space syntax and spatialinterfaces: The case of river cities2017In: A|Z ITU Journal of the Faculty of Architecture, ISSN 1303-7005, Vol. 14, no 1, p. 25-41Article in journal (Refereed)
    Abstract [en]

    Resilience defined as the capacity of a system to manage impacts, keep its efficiency and continue its development has been scrutinized by researchers from different points of view over the past decades. Due to the prominence of resilience in urban planning, this paper intends to find out how the spatial structure of cities deals with disturbances, and if geographical phenomena such as rivers affect the resilience in cities. Using the space syntax methods syntactically analyze the resilience in cities, we innovatively introduce two measures; similarity and sameness. These measures are in relation with the syntactical properties of cities and compare the degree of resilience between different groups. Similarity measures the degree to which each city retains the relative magnitude of its foreground network after a disturbance and sameness is the degree to which each city retains the same segments as its foreground network after a disturbance. Likewise to network resilience studies, we apply different disturbances on cities and explore the reaction of cities to disturbances in terms of size of the foreground network and which segments are parts thereof. We then compare different groups based on these measurements as a method to analyze sameness and similarity. The results show that the resilience, in the way we define it, is different in different cities depending on in which view and based on which parameters we are discussing the resilience. Additionally morphological phenomena such as rivers have a great impact on the structure of cities and in turn on their resilience.

  • 273.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Rivers as integration devices in cities2016In: City, Territory and Architecture, ISSN 0885-7024, E-ISSN 2195-2701, Vol. 3, no 1, p. 1-21Article in journal (Refereed)
    Abstract [en]

    Background: As dynamic systems rivers and cities have been in interaction under changing relations over time, and the morphology of many cities has risen through a long and steady struggle between the city functions and the river system flowing inside. This makes river cities an interesting case to study how the presence of geographical features interacts with spatial morphology in the formation of cities.

    Methods: The basis of this research is enabled by utilizing a novel model for cross-city comparison presented by Hillier in his Santiago keynote in 2012 called a “star model”. This is done on large samples of cities investigating concurrent configurations, as well as how the properties in this star model react to specific forms of disturbance.

    Results: Results illustrate that the foreground network as identified through maximum choice values in cities are more vital to the structure of cities than the bridges. The overall syntactic structure tends to retain its character (degree of distributedness) and the location of its foreground network (which street segments constitute the foreground network) even when bridges are targeted. Furthermore, counter to the initial hypothesis, river cities tend to change less than non-river cities after targeted disturbance of the systems. Finally, the results show that while there is a statistical morphological difference between river cities and non-river cities, this difference is not directly explained through the bridges.

    Conclusion: Integrating space syntax with statistical and geospatial analysis can throw light on the way in which the properties of city networks and urban structure reflect the relative effect of rivers on the morphology of river cities. The paper, finally, contributes through offering one piece of a better perception of the structure of river-cities that can support strategies of river-cities interaction as well as enhance our knowledge on the constraints and limits to that interaction.

  • 274.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Visibility Analysis, Similarity and Dissimilarity in General Trends of Building Layouts and their Functions2013In: Proceedings of Ninth International Space Syntax Symposium / [ed] Young Ook Kim, Hoon Tae Park, Kyung Wook Seo, Seoul: Sejong University Press , 2013, p. 11:1-11:15Conference paper (Refereed)
    Abstract [en]

    Visibility analysis is one of the key methods in space syntax theory that discusses visual information conveyed to observers from any location in space that is potentially directly visible for the observer without any obstruction. Visibility – simply defined as what we can see – not only affects the spatial function of buildings, but also has visual relation to the perception of buildings by inhabitants and visitors. In this paper we intend to present the result of visibility analysis applied on a sample of building layouts of different sizes and functions from a variety of places of periods. The main aim of this paper is to statistically explore the general trends of building layouts and show if and how visibility properties such as connectivity, clustering coefficient, mean depth, entropy, and integration values can make distinctions among different functions of buildings. Our findings reveal that there are significant correlation coefficients among global properties of visibility in which we consider the mean value of properties, a similarity suggesting that they are not intensively manipulated by architecture. On the other hand, there are correlations although less so than the previous, still significant among local properties of visibility in which we consider the (max-min) value of properties, suggesting that social, cultural or other physical parameters distinguish buildings individually. We also show that functions such as ‘museum’ and ‘veterinary’ are relatively well-clustered, while functions such as ‘ancient’ and ‘shopping’ show high diversity. In addition, using a decision tree model we show that, in our sample, functions such as ‘museum’ and ‘library’ are more predictable rather than functions such as ‘hospital’ and ‘shopping.’ All of these mean that – at least in our sample – the usability and applicability of well-clustered and well-predicted functions have been predominant in shaping their interior spaces; vice versa, in well-diverse and unpredicted functions, the pragmatic solutions of people’s daily life developed in material culture affect the visual properties of their interior spaces.

  • 275.
    Abtahi, Farhad
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Aspects of Electrical Bioimpedance Spectrum Estimation2014Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Electrical bioimpedance spectroscopy (EBIS) has been used to assess the status or composition of various types of tissue, and examples of EBIS include body composition analysis (BCA) and tissue characterisation for skin cancer detection. EBIS is a non-invasive method that has the potential to provide a large amount of information for diagnosis or monitoring purposes, such as the monitoring of pulmonary oedema, i.e., fluid accumulation in the lungs. However, in many cases, systems based on EBIS have not become generally accepted in clinical practice. Possible reasons behind the low acceptance of EBIS could involve inaccurate models; artefacts, such as those from movements; measurement errors; and estimation errors. Previous thoracic EBIS measurements aimed at pulmonary oedema have shown some uncertainties in their results, making it difficult to produce trustworthy monitoring methods. The current research hypothesis was that these uncertainties mostly originate from estimation errors. In particular, time-varying behaviours of the thorax, e.g., respiratory and cardiac activity, can cause estimation errors, which make it tricky to detect the slowly varying behaviour of this system, i.e., pulmonary oedema.

    The aim of this thesis is to investigate potential sources of estimation error in transthoracic impedance spectroscopy (TIS) for pulmonary oedema detection and to propose methods to prevent or compensate for these errors.   This work is mainly focused on two aspects of impedance spectrum estimation: first, the problems associated with the delay between estimations of spectrum samples in the frequency-sweep technique and second, the influence of undersampling (a result of impedance estimation times) when estimating an EBIS spectrum. The delay between frequency sweeps can produce huge errors when analysing EBIS spectra, but its effect decreases with averaging or low-pass filtering, which is a common and simple method for monitoring the time-invariant behaviour of a system. The results show the importance of the undersampling effect as the main estimation error that can cause uncertainty in TIS measurements.  The best time for dealing with this error is during the design process, when the system can be designed to avoid this error or with the possibility to compensate for the error during analysis. A case study of monitoring pulmonary oedema is used to assess the effect of these two estimation errors. However, the results can be generalised to any case for identifying the slowly varying behaviour of physiological systems that also display higher frequency variations.  Finally, some suggestions for designing an EBIS measurement system and analysis methods to avoid or compensate for these estimation errors are discussed.

  • 276.
    Abtahi, Farhad
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Towards Heart Rate Variability Tools in P-Health: Pervasive, Preventive, Predictive and Personalized2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Heart rate variability (HRV) has received much attention lately. It has been shown that HRV can be used to monitor the autonomic nervous system and to detect autonomic dysfunction, especially vagal dysfunction. Reduced HRV is associated with several diseases and has also been suggested as a predictor of poor outcomes and sudden cardiac death. HRV is, however, not yet widely accepted as a clinical tool and is mostly used for research. Advances in neuroimmunity with an improved understanding of the link between the nervous and immune systems have opened a new potential arena for HRV applications. An example is when systemic inflammation and autoimmune disease are primarily caused by low vagal activity; it can be detected and prognosticated by reduced HRV. This thesis is the result of several technical development steps and exploratory research where HRV is applied as a prognostic diagnostic tool with preventive potential. The main objectives were 1) to develop an affordable tool for the effective analysis of HRV, 2) to study the correlation between HRV and pro-inflammatory markers and the potential degree of activity in the cholinergic anti-inflammatory pathway, and 3) to develop a biofeedback application intended for support of personal capability to increase the vagal activity as reflected in increased HRV. Written as a compilation thesis, the methodology and the results of each study are presented in each appended paper. In the thesis frame/summary chapter, a summary of each of the included papers is presented, grouped by topic and with their connections. The summary of the results shows that the developed tools may accurately register and properly analyse and potentially influence HRV through the designed biofeedback game. HRV can be used as a prognostic tool, not just in traditional healthcare with a focus on illness but also in wellness. By using these tools for the early detection of decreased HRV, prompt intervention may be possible, enabling the prevention of disease. Gamification and serious gaming is a potential platform to motivate people to follow a routine of exercise that might, through biofeedback, improve HRV and thereby health.

  • 277.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Berndtsson, Andreas
    Abtahi, Shirin
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Development and preliminary evaluation of an Android based heart rate variability biofeedback system2014In: Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE, IEEE conference proceedings, 2014, p. 3382-3385Conference paper (Refereed)
    Abstract [en]

    The reduced Heart Rate Variability (HRV) is believed to be associated with several diseases such as congestive heart failure, diabetes and chronic kidney diseases (CKD). In these cases, HRV biofeedback may be a potential intervention method to increase HRV which in turn is beneficial to these patients. In this work, a real-time Android biofeedback application based on a Bluetooth enabled ECG and thoracic electrical bioimpedance (respiration) measurement device has been developed. The system performance and usability have been evaluated in a brief study with eight healthy volunteers. The result demonstrates real-time performance of system and positive effects of biofeedback training session by increased HRV and reduced heart rate. Further development of the application and training protocol is ongoing to investigate duration of training session to find an optimum length and interval of biofeedback sessions to use in potential interventions.

  • 278. Abtahi, Farhad
    et al.
    Forsman, Mikael
    Diaz-Olivazrez, Jose A.
    KTH, School of Technology and Health (STH).
    Yang, Liyun
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Ergonomics.
    Lu, Ke
    KTH, School of Technology and Health (STH).
    Eklund, Jörgen
    KTH, School of Technology and Health (STH).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH).
    Seoane, Fernando
    Teriö, Heikki
    Mediavilla Martinez, Cesar
    Aso, Santiago
    Tiemann, Christian
    Big Data & Wearable Sensors Ensuring Safety and Health @Work2017In: GLOBAL HEALTH 2017, The Sixth International Conference on Global Health Challenges, 2017Conference paper (Refereed)
    Abstract [en]

    —Work-related injuries and disorders constitute a major burden and cost for employers, society in general and workers in particular. We@Work is a project that aims to develop an integrated solution for promoting and supporting a safe and healthy working life by combining wearable technologies, Big Data analytics, ergonomics, and information and communication technologies. The We@Work solution aims to support the worker and employer to ensure a healthy working life through pervasive monitoring for early warnings, prompt detection of capacity-loss and accurate risk assessments at workplace as well as self-management of a healthy working life. A multiservice platform will allow unobtrusive data collection at workplaces. Big Data analytics will provide real-time information useful to prevent work injuries and support healthy working life

  • 279.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Karolinska Institutet, Sweden.
    Hilderman, Marie
    Bruchfeld, Annette
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. University of Borås, Sweden.
    Janerot-Sjöberg, Birgitta
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging. Karolinska Institutet, Sweden.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Karolinska Institutet, Sweden.
    Pro-inflammatory Blood Markers and Heart Rate Variability in Apnoea as a Reflection of Basal Vagal ToneManuscript (preprint) (Other academic)
    Abstract [en]

    Pro-inflammatory cytokines play a crucial role in inflammatory response, which istightly regulated by the nervous system to avoid the damage caused by inflammation. There isevidence for a cholinergic anti-inflammatory pathway that includes afferent and efferent vagalnerves that sense the inflammation and stimulate the anti-inflammatory response. Non-functionalanti-inflammatory response might lead to excessive and chronic inflammation e.g., rheumatoidarthritis (RA), inflammatory bowel disease (IBD), and poor outcome. Heart rate variability(HRV) has been proposed as a potential tool to monitor the level of anti-inflammatory activitythrough the monitoring of vagal activity. In this paper, the association of pro-inflammatorymarkers with HRV indices is evaluated. We used a database called “Heart Biomarker Evaluationin Apnea Treatment (HeartBEAT)” that consists of 6±2 hours of Electrocardiogram (ECG)recordings during nocturnal sleep from 318 patients at baseline and 301of them at 3 monthsfollow-up. HRV indices are calculated from ECG recordings of 5-360 minutes. The results showa statistically significant correlation between heart rate (HR) and pro-inflammatory cytokines,independent of duration of ECG analysis. HRV indices e.g., standard deviation of all RRintervals (SDNN) show an inverse relation to the pro-inflammatory cytokines. Longer ECGrecordings show a higher potential to reflect the level of anti-inflammatory response. In light oftheories for the cholinergic anti-inflammatory pathway, a combination of HR and HRV as areflection of basal vagal activity might be a potential prognostic tool for interventional guidance.

  • 280.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Ji, Guangchao
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Rodby, Kristian
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    A knitted garment using intarsia technique for Heart Rate Variability biofeedback: Evaluation of initial prototype2015In: Engineering in Medicine and Biology Society (EMBC), 2015 37th Annual International Conference of the IEEE, IEEE , 2015, Vol. 2015, p. 3121-3124Conference paper (Refereed)
    Abstract [en]

    Heart rate variability (HRV) biofeedback is a method based on paced breathing at specific rate called resonance frequency by giving online feedbacks from user respiration and its effect on HRV. Since the HRV is also influence by different factors like stress and emotions, stress related to an unfamiliar measurement device, cables and skin electrodes may cover the underling effect of such kind of intervention. Wearable systems are usually considered as intuitive solutions which are more familiar to the end-user and can help to improve usability and hence reducing the stress. In this work, a prototype of a knitted garment using intarsia technique is developed and evaluated. Results show the satisfactory level of quality for Electrocardiogram and thoracic electrical bioimpedance i.e. for respiration monitoring as a part of HRV biofeedback system. Using intarsia technique and conductive yarn for making the connection instead of cables will reduce the complexity of fabrication in textile production and hence reduce the final costs in a final commercial product. Further development of garment and Android application is ongoing and usability and efficiency of final prototype will be evaluated in detail.

  • 281.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Ji, Guangchao
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Björlin, Anders
    Kiwok AB.
    Östlund, Anders
    Kiwok AB.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Textile-Electronic Integration in Wearable Measurement Garments for Pervasive Healthcare Monitoring2015Conference paper (Other academic)
  • 282.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Aslamy, Benjamin
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Boujabir, Imaneh
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    An Affordable ECG and Respiration Monitoring System Based on Raspberry PI and ADAS1000: First Step towards Homecare Applications2015In: 16th Nordic-Baltic Conference on Biomedical Engineering: 16. NBC & 10. MTD 2014 joint conferences. October 14-16, 2014, Gothenburg, Sweden, Springer, 2015, p. 5-8Conference paper (Refereed)
    Abstract [en]

    Homecare is a potential solution for problems associated with an aging population. This may involve several physiological measurements, and hence a flexible but affordable measurement device is needed. In this work, we have designed an ADAS1000-based four-lead electrocardiogram (ECG) and respiration monitoring system. It has been implemented using Raspberry PI as a platform for homecare applications. ADuM chips based on iCoupler technology have been used to achieve electrical isolation as required by IEC 60601 and IEC 60950 for patient safety. The result proved the potential of Raspberry PI for the design of a compact, affordable, and medically safe measurement device. Further work involves developing a more flexible software for collecting measurements from different devices (measuring, e.g., blood pressure, weight, impedance spectroscopy, blood glucose) through Bluetooth or user input and integrating them into a cloud-based homecare system.

  • 283.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Dizon, M
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Johansson, M
    KTH-School of Technology and Health.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Högskolan i Borås.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Evaluating Atrial Fibrillation Detection Algorithm based on Heart Rate Variability analysis2015In: Medicinteknikdagarna, Uppsala: Svensk förening för medicinsk teknik och fysik , 2015Conference paper (Refereed)
  • 284.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Dizon, M
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Johansson, M
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Evaluation of Atrial Fibrillation Detection by using Heart Rate Variability analysis2015Conference paper (Other academic)
  • 285.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Guangchao, Li
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Högskolan i Borås.
    A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.2015Conference paper (Other academic)
  • 286.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Electrical bioimpedance spectroscopy in time-variant systems: Is undersampling always a problem?2014In: Journal of Electrical Bioimpedance, ISSN 1891-5469, Vol. 5, no 1, p. 28-33Article in journal (Refereed)
    Abstract [en]

    During the last decades, Electrical Bioimpedance Spectroscopy (EBIS) has been applied mainly by using the frequency-sweep technique, across a range of many different applications. Traditionally, the tissue under study is considered to be time-invariant and dynamic changes of tissue activity are ignored by treating the changes as a noise source. A new trend in EBIS is simultaneous electrical stimulation with several frequencies, through the application of a multi-sine, rectangular or other waveform. This method can provide measurements fast enough to sample dynamic changes of different tissues, such as cardiac muscle. This high sampling rate comes at a price of reduction in SNR and the increase in complexity of devices. Although the frequency-sweep technique is often inadequate for monitoring the dynamic changes in a variant system, it can be used successfully in applications focused on the time-invariant or slowly-variant part of a system. However, in order to successfully use frequency-sweep EBIS for monitoring time-variant systems, it is paramount to consider the effects of aliasing and especially the folding of higher frequencies, on the desired frequency e.g. DC level. This paper discusses sub-Nyquist sampling of thoracic EBIS measurements and its application in the case of monitoring pulmonary oedema. It is concluded that by considering aliasing, and with proper implementation of smoothing filters, as well as by using random sampling, frequency-sweep EBIS can be used for assessing time-invariant or slowly-variant properties of time-variant biological systems, even in the presence of aliasing. In general, undersampling is not always a problem, but does always require proper consideration.

  • 287.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Löfgren, Nils
    Elimination of ECG Artefacts in Foetal EEG Using Ensemble Average Subtraction and Wavelet Denoising Methods: A Simulation2014In: XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013, Springer, 2014, p. 551-554Conference paper (Refereed)
    Abstract [en]

    Biological signals recorded from surface electrodes contain interference from other signals which are not desired and should be considered as noise. Heart activity is especially present in EEG and EMG recordings as a noise. In this work, two ECG elimination methods are implemented; ensemble average subtraction (EAS) and wavelet denoising methods. Comparison of these methods has been done by use of simulated signals achieved by adding ECG to neonates EEG. The result shows successful elimination of ECG artifacts by using both methods. In general EAS method which remove estimate of all ECG components from signal is more trustable but it is also harder for implementation due to sensitivity to noise. It is also concluded that EAS behaves like a high-pass filter while wavelet denoising method acts as low-pass filter and hence the choice of one method depends on application.

  • 288.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Snäll, Jonatan
    KTH, School of Technology and Health (STH).
    Aslamy, Benjamin
    KTH, School of Technology and Health (STH).
    Abtahi, Shirin
    KTH, School of Technology and Health (STH).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. University of Boras, Sweden.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Karolinska Institute, Sweden.
    Biosignal PI, an Affordable Open-Source ECG and Respiration Measurement System2014In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 15, no 1, p. 93-109Article in journal (Refereed)
    Abstract [en]

    Bioimedical pilot projects e.g., telemedicine, homecare, animal and human trials usually involve several physiological measurements. Technical development of these projects is time consuming and in particular costly. A versatile but affordable biosignal measurement platform can help to reduce time and risk while keeping the focus on the important goal and making an efficient use of resources. In this work, an affordable and open source platform for development of physiological signals is proposed. As a first step an 8–12 leads electrocardiogram (ECG) and respiration monitoring system is developed. Chips based on iCoupler technology have been used to achieve electrical isolation as required by IEC 60601 for patient safety. The result shows the potential of this platform as a base for prototyping compact, affordable, and medically safe measurement systems. Further work involves both hardware and software development to develop modules. These modules may require development of front-ends for other biosignals or just collect data wirelessly from different devices e.g., blood pressure, weight, bioimpedance spectrum, blood glucose, e.g., through Bluetooth. All design and development documents, files and source codes will be available for non-commercial use through project website, BiosignalPI.org.

  • 289.
    Abtahi, Farzad
    KTH, School of Information and Communication Technology (ICT).
    Optimal Design of Cost- and Energy-Efficient ScalablePassive Optical Backbone Networks2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Advances in optical coherent transmissions and electrical compensation technologies have stimulated the exploration of novel optical network architectures. Filterless optical backbone networks (F-OBNs) eliminate or minimize the usage of active photonic reconfigurable components, which is also referred to as passive OBN. By introducing passive splitters and combiners to interconnect the fiber links, this type of networks have been proposed as a cost- and energy-efficient alternative to active optical switching networks.

    However, F-OBN suffers from a constraint on wavelength reuse due to its broadcast nature. Consequently, this architecture always requires more resources, i.e. higher number of wavelengths, than the active optical switching networks. To address this issue, another passive approach for optical core network, i.e., semi-filterless OBN (SF-OBN) has been introduced. By utilizing passive colored components, e.g., Fiber Bragg Grating (FBG), red/blue filters, etc., at some selected nodes, the SF-OBN is able to improve the wavelength usage while keeping the similar level on cost and energy consumption as FOBN. In this thesis project, an optimization model for wavelength assignment and filter placement in SF-OBN has been developed. F-OBN can be considered as a special case without any filter in SF-OBN. Using integer linear programming (ILP) formulation, the model aims to minimize the total number of wavelengths required in the network given the number of filters.

    Furthermore, wavelength usage, cost and energy consumption in active optical switching, F-OBN and SF-OBN have been compared in order to evaluate the performance of the each network architecture.

  • 290.
    Abtahi, Farzad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Khanmohamadi, Sahar
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Mantelet, G.
    Archambault, E.
    Tremblay, C.
    Bélanger, M. P.
    Optimal Design of Cost- and Energy-Efficient Scalable Passive Optical Backbone Networks2012In: 2012 Asia Communications And Photonics Conference (ACP), 2012, p. AS3D.4-Conference paper (Refereed)
    Abstract [en]

    We propose an optimization model minimizing number of wavelengths in passive optical backbone networks and obtaining the same resource usage as in networks based on active switching while reducing both cost and power consumption.

  • 291.
    Abtin, Soltanpour
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Ayanle, Sheikhdahir
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Utvärdering och implementering av ett prognosverktyg hos Qibbla Halal2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 292.
    Abu Zeid, Houda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Syed, Tanya
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Suitable textile recycling methods for implementation inSweden: A study in mechanical and chemical recycling methods2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report strives to examine the economical, technical and environmental aspects of textileproduction, but mainly textile recycling. Comparisons between natural fibers and syntheticones will be made, comparing both positive and negative aspects. The textile fibers that willbe discussed are cotton, viscose, polyester and lyocell. Furthermore, an analysis of varioustextile recycling technologies currently available and how suited they are for today’s societywill be made. By doing so one can explore the future possibilities and limitations for thedevelopment of textile recycling. A SWOT-analysis will be conducted in order to examinethe possibility to implement one of the recycling techniques in Sweden. The conclusion thatformed from the SWOT-analysis was that the chemical recycling technique is better fitted fora country of Sweden’s nature. Furthermore, in order for Sweden to be able to implement alarge scale recycling system there is a need for development of certain areas, such as sortingtechnologies, collection and general managing of recycled textile fibers. Some furtherconclusions from this study are that:● Greater focus is needed in order to increase the collection of textiles, since thechemical recycling method is the most efficient when it comes to the recycling oflarger volumes of textiles.● The majority of the sorting of textiles should be done automatically to facilitate thehandling of the collection of textiles.● In the beginning one should focus on recycling textiles that only consist of one type offiber, this since the recycling of textiles consisting of more than one type of fiber ismore complex and the technique for it is not yet fully developed.There are two parts to the report. The first part contains an introduction and a description ofthe project’s research questions and mission. The second part is a literature study whichcontains information about different types of textile fibers currently available and how theproduction and recycling of these fibers affect the environment and society as a whole. Theliterature study is followed by a description of the model used in this report and also ananalysis of the final results. An interview conducted with the sportswear company HoudiniSportswear AB can also be found in the literature study.

  • 293.
    Abuasbeh, Mohammad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Fault Detection and Diagnosis for Brine to Water Heat Pump Systems2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The overall objective of this thesis is to develop methods for fault detection and diagnosis for ground source heat pumps that can be used by servicemen to assist them to accurately detect and diagnose faults during the operation of the heat pump. The aim of this thesis is focused to develop two fault detection and diagnosis methods, sensitivity ratio and data-driven using principle component analysis.

    For the sensitivity ratio method model, two semi-empirical models for heat pump unit were built to simulate fault free and faulty conditions in the heat pump. Both models have been cross-validated by fault free experimental data. The fault free model is used as a reference. Then, fault trend analysis is performed in order to select a pair of uniquely sensitive and insensitive parameters to calculate the sensitivity ratio for each fault. When a sensitivity ratio value for a certain fault drops below a predefined value, that fault is diagnosed and an alarm message with that fault appears. The simulated faults data is used to test the model and the model successfully detected and diagnosed the faults types that were tested for different operation conditions.

    In the second method, principle component analysis is used to drive linear correlations of the original variables and calculate the principle components to reduce the dimensionality of the system. Then simple clustering technique is used for operation conditions classification and fault detection and diagnosis process. Each fault is represented by four clusters connected with three lines where each cluster represents different fault intensity level. The fault detection is performed by measuring the shortest orthogonal distance between the test point and the lines connecting the faults’ clusters. Simulated fault free and faulty data are used to train the model. Then, a new set of simulated faults data is used to test the model and the model successfully detected and diagnosed all faults type and intensity level of the tested faults for different operation conditions.

    Both models used simple seven temperature measurements, two pressure measurements (from which the condensation and evaporation temperatures are calculated) and the electrical power, as an input to the fault detection and diagnosis model. This is to reduce the cost and make it more convenient to implement. Finally, for each models, a user friendly graphical user interface is built to facilitate the model operation by the serviceman.

  • 294. Abubakar, Abdulkareem
    et al.
    Al-Wahaibi, Yahya
    Al-Wahaibi, Talal
    Al-Hashmi, Abdul-Aziz R.
    Al-Ajmi, Adel M.
    KTH.
    Eshrati, Mohammad
    Effect of Water-Soluble Drag-Reducing Polymer on Flow Patterns and Pressure Gradients of Oil/Water Flow in Horizontal and Upward-Inclined Pipes2017In: SPE Journal, ISSN 1086-055X, E-ISSN 1930-0220, Vol. 22, no 1, p. 339-352Article in journal (Refereed)
    Abstract [en]

    Experimental investigations of flow patterns and pressure gradients of oil/water flow with and without drag-reducing polymer (DRP) were carried out in horizontal and upward-inclined acrylic pipe of 30.6-mm inner diameter (ID). The oil/water flow conditions of 0.1- to 1.6-m/s mixture velocities and 0.05-0.9 input oil volume fractions were used, and 2,000 ppm master solution of the water-soluble DRP was prepared and injected at controlled flow rates to provide 40 ppm of the DRP in the water phase at the test section. The flow patterns at the water-continuous flows were affected by the DRP, whereas there were no tangible effects of the DRP at the oil-continuous flow regions. The upward inclinations shifted the boundaries between stratified flows and dual continuous flows, and the boundaries between dual continuous flows and water-continuous flows to lower mixture velocities. This means that the inclinations increased the rate of dispersions. The frictional pressure gradients for both with and without DRP slightly decreased with inclinations especially at low mixture velocities, whereas the significant increases in the total pressure gradients with the inclinations were more pronounced at low mixture velocities. The inclinations did not have a major effect on the drag reductions by the DRP at the high mixture velocities and low input oil-volume fractions where the highest drag reductions recorded were 64% at 0 degrees inclination and 62% at both + 5 degrees and +10 degrees inclinations.  However, the inclinations increased the drag reductions as the input oil-volume fractions were increased before phase-inversion points.

  • 295. Abu-Ghunmi, Diana
    et al.
    Abu-Ghunmi, Lina
    Kayal, Bassam
    KTH, School of Industrial Engineering and Management (ITM).
    Bino, Adel
    Circular economy and the opportunity cost of not 'closing the loop' of water industry: the case of Jordan2016In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 131, p. 228-236Article in journal (Refereed)
    Abstract [en]

    The water industry is moving from an end-of-pipe approach consistent with the linear economic model to a circular approach consistent with the circular economy model. The economic dimension of wastewater circularity has not received the attention that other dimensions have; this study attempts to fill this research gap by studying the economic dimension, in order to estimate the net opportunity cost of a non-circular water industry The financial and environmental benefits of treating wastewater, along with the associated operating and capital costs, are calculated to arrive at the opportunity cost and the 'closing the loop charge'. The analytical results reveal an estimated net opportunity cost of 643 million Jordanian dinar (JOD) (907 million US$) if the option not to go circular is chosen, with JOD 212 million (US$ 299 million) of this amount currently squandered. Furthermore, this indicates an average 'closing the loop charge' of JOD0.70/m(3) ($1.0/m(3)), which represents the average shadow price of the associated environmental externalities. Having thus shown a strong economic case for the circular model in the water industry, movements in all economic sectors to adhere to this model appear to be highly desirable.

  • 296.
    Abukar, Hared
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Al Saati, Firas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Weda pool cleaner Concept P1002016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to develop a new drivetrain for Wedas current robot pool cleaner W50. Currently, the pump is integrated in the drivetrain which contains only one motor running both wheels and pump. This causes a critical problem affecting cleaning when encountering inclinations in the pool, the robot slides down the slope. To get a better understanding of how the product works, the project group made study visits to Weda. The group documented and observed how the current model and its components are mounted. Interviews were conducted with caretakers and janitors at various municipal swimming pools and hotel pools to get a deeper understanding of how these robot pool cleaners are used and what areas for improvement that exists. The research was used as a foundation for suggestions of new and alternative components for the new concept. The different solutions were then evaluated using a decision matrix to determine which components should be included in the final concept. The work has been carried out in close cooperation with Adigo Drives, which assisted the group with their expertise regarding motors and powertrains. The results culminated in a final concept with a new powertrain and a lower weight than the existing robot.

  • 297.
    ABUKAR, HARED
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    PETTERSSON, FREDRIK
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Design koncept för kommersiella applikationer2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 298. Abu-Khader, M. M.
    et al.
    Shawaqfeh, A. T.
    Naddaf, Z.
    Maity, J. P.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Radon in the groundwater in the Amman-Zarqa Basin and related environments in Jordan2018In: Groundwater for Sustainable Development, ISSN 2352-801X, Vol. 7, p. 73-81Article in journal (Refereed)
    Abstract [en]

    The occurrence of radon (222Rn) in environment (groundwater and indoor air) from geogenic sources is receiving an growing attention due to its adverse impact on human health worldwide including Jordan. Highlighting the current status of radon in Jordan, the present study of radon concentrations in ground waters in the Amman-Zarqa basin (AZB) was investigated. Groundwater samples were collected from fifteen wells located in three main areas of Ras Al-Ain, Al-Rsaifeh and Al-Hashemite. Radon concentration was measure using Liquid scintillation counting (LSC) Tri- Carb 3110 with discriminator and the highest values for radon concentration in water were observed in Al-Rsaifeh area and ranged from 4.52 up to 30.70 Bq/l with an average of 11.22 Bq/l, which were attributed to the decay of naturally distributed uranium in phosphate rock from Al-Rsaifeh mines. In Ras Al-Ain area, the radon concentration were noted ranged from 0.6 to 5.55 Bq/l with an average of 2.82 Bq/l, and also in Al-Hashemite area were ranged from 0.77 to 5.37 Bq/l with an average of 4.04 Bq/l. The overall average concentration of tested samples was 5.77 Bq/l and found within the acceptable international levels. Ground water samples of Ras Al-Ain area showed good quality as was tested of low salinity. It recorded the lowest average radon concentration of 2.82 Bq/l. Also, Radon indoor and building materials was reviewed. In conclusion, this study presented an urged need for developing national regulations and standards as well as awareness program concerning the radon status in Jordan.Elsevier B.V.

  • 299. Abu-Lebdeh, Mohammad
    et al.
    Sahoo, Jagruti
    Glitho, Roch
    KTH.
    Tchouati, Constant Wette
    Cloudifying the 3GPP IP Multimedia Subsystem for 4G and Beyond: A Survey2016In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 54, no 1, p. 91-97Article in journal (Refereed)
    Abstract [en]

    4G systems have been continuously evolving to cope with the emerging challenges of human-centric and M2M applications. Research has also now started on 5G systems. Scenarios have been proposed and initial requirements derived. 4G and beyond systems are expected to easily deliver a wide range of human-centric and M2M applications and services in a scalable, elastic, and cost-efficient manner. The 3GPP IMS was standardized as the service delivery platform for 3G networks. Unfortunately, it does not meet several requirements for provisioning applications and services in 4G and beyond systems. However, cloudifying it will certainly pave the way for its use as a service delivery platform for 4G and beyond. This article presents a critical overview of the architectures proposed so far for cloudifying the IMS. There are two classes of approaches; the first focuses on the whole IMS system, and the second deals with specific IMS entities. Research directions are also discussed. IMS granularity and a PaaS for the development and management of IMS functional entities are the two key directions we currently foresee.

  • 300. Abu-Odeh, A.
    et al.
    Galvan, E.
    Kirk, T.
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Chen, Q.
    Mason, P.
    Malak, R.
    Arróyave, R.
    Efficient exploration of the High Entropy Alloy composition-phase space2018In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 152, p. 41-57Article in journal (Refereed)
    Abstract [en]

    High Entropy Alloys (HEAs), Multi-principal Component Alloys (MCA), or Compositionally Complex Alloys (CCAs) are alloys that contain multiple principal alloying elements. While many HEAs have been shown to have unique properties, their discovery has been largely done through costly and time-consuming trial-and-error approaches, with only an infinitesimally small fraction of the entire possible composition space having been explored. In this work, the exploration of the HEA composition space is framed as a Continuous Constraint Satisfaction Problem (CCSP) and solved using a novel Constraint Satisfaction Algorithm (CSA) for the rapid and robust exploration of alloy thermodynamic spaces. The algorithm is used to discover regions in the HEA Composition-Temperature space that satisfy desired phase constitution requirements. The algorithm is demonstrated against a new (TCHEA1) CALPHAD HEA thermodynamic database. The database is first validated by comparing phase stability predictions against experiments and then the CSA is deployed and tested against design tasks consisting of identifying not only single phase solid solution regions in ternary, quaternary and quinary composition spaces but also the identification of regions that are likely to yield precipitation-strengthened HEAs.

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